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South Island Eel Industry Association Eel Fishery Plan for the South Island

South Island Eel Industry Association
Eel Fishery Plan for the South Island
September 2009
Prepared for the South Island Eel Industry Association by
Chisholm Associates, PO Box 11014, Dunedin
South Island Eel Industry Association: Eel Management Plan September 2009
Table of Contents
1. BACKGROUND .................................................................................. 3
2. INTRODUCTION ............................................................................... 4
2.1 Marine Stewardship Council (MSC) ................................................................... 4
2.2 Plan Review ........................................................................................................ 5
3. 1. South Island Quota Management System (QMS) ............................................. 5
3.2 Commercial Catch Levels ................................................................................... 7
4.1 Catch per unit effort (CPUE) .............................................................................. 8
4.2 Recruitment ....................................................................................................... 10
4.3 Conclusion ........................................................................................................ 11
5. STATUS OF LONGFIN EEL POPULATIONS ............................ 11
6. EEL ENHANCEMENT .................................................................... 14
6.1 Upstream elver transfer ..................................................................................... 14
6.2 Downstream migrating transfer ........................................................................ 16
7. OTHER SUSTAINABILITY ISSUES ............................................. 17
7.1 Other Sources Of Mortality .............................................................................. 17
7.2 Illegal catch ....................................................................................................... 18
7.3 Yield-per-recruit ............................................................................................... 18
7.4 Sex ratio ............................................................................................................ 19
7.5 Shortfin/Longfin Ratio ...................................................................................... 20
7.6 Trophic cascade ............................................................................................... 20
7.7 Minimum Quota holding................................................................................... 21
7.8 Summary of measures to maintain a sustainable fishery ................................. 21
8. HABITAT AND ENVIRONMENTAL ISSUES ............................. 21
8.1 Discharges ......................................................................................................... 21
8.2 Land Use ........................................................................................................... 23
8.3 Agrichemicals and fertilisers ............................................................................ 24
8.4 Riparian Areas .................................................................................................. 25
8.5 Water Abstraction ............................................................................................. 27
8.6 Weed clearance and drainage ............................................................................ 28
8.7 Wetland protection and enhancement ............................................................... 29
8.8 Channelling and flood protection works ........................................................... 30
8.9 Gravel and sand removal .................................................................................. 31
8.10 Barriers to Eel Migration ................................................................................ 32
9. Lake Ellesmere/Te Waihora ............................................................. 35
9.1 Lake levels and Lake Opening .......................................................................... 35
9.2 Longfin Eels ...................................................................................................... 36
9.3 Migratory Eels .................................................................................................. 36
9.4 Other Lake Ellesmere/Te Waihora issues ......................................................... 37
10. BIOSECURITY ............................................................................... 38
10.1 Didymo ........................................................................................................... 39
10.2 Other aquatic weeds ........................................................................................ 39
10.3 Pest Fish .......................................................................................................... 40
South Island Eel Industry Association: Eel Management Plan September 2009
11.1 Maori Customary Interests and mataitai ......................................................... 41
11.2 Ministry of Fisheries ....................................................................................... 42
11.3 Department of Conservation (DoC) ................................................................ 42
11.4 Regional and District Councils ...................................................................... 44
11.5 Other Government Departments ..................................................................... 46
11.6 Fish & Game Councils .................................................................................... 46
12. MISCELLANEOUS ISSUES ......................................................... 47
12.1 Illegal activities ............................................................................................... 47
12.2 Bycatch ............................................................................................................ 47
12.3 Consultation .................................................................................................... 47
13. MSC PRINCIPLE 3 ........................................................................ 48
13.1 Management System Criteria: .......................................................................... 48
13.2 Operational Criteria ......................................................................................... 50
14. RESEARCH ..................................................................................... 50
15. REFERENCES ................................................................................ 51
APPENDICES ......................................................................................... 52
APPENDIX 1: Commercial eel catch data ............................................................. 52
APPENDIX 2: New Zealand Eel Biology .............................................................. 55
APPENDIX 3: Eel Fisheries ................................................................................... 59
APPENDIX 4: Eel Quota Management Areas ....................................................... 61
APPENDIX 5: Policy on minimising the spread of didymo .................................. 62
Cover Photo: Releasing migrant female shortfin eels to the sea from Lake
Ellesmere/Te Waihora
South Island Eel Industry Association AGM. September 2009
South Island Eel Industry Association: Eel Management Plan September 2009
The South Island commercial eel industry currently involves 32 commercial eel
harvesters taking the majority of the catch in the South Island. South Island Eel
Industry Association (SIEIA) members comprise the majority of the eel permit
holders. There are up to six eel processing plants servicing this catch, mainly in
Christchurch and Invercargill. The South Island commercial eel fishery has a
commercial export value of approximately 10 million dollars. Industries servicing the
commercial eel industry have been estimated to maintain approximately 200 full-time
equivalent (FTE) jobs.
In 1996, the South Island Eel Fishery Plan gained Ministerial approval. This Plan was
developed by the Working Group known as Te Waahi Pounamu Eel Working Group.
The broad purposes of this 1996 Plan were to bring the South Island eel fishery into
the Quota Management System (QMS), and then sustainably manage the fishery into
the future.
South Island eels were brought into a QMS in 2000, with six Eel Quota Management
Areas (ANG 11 – 16). Catch information from these six Eel Management Areas is
now available. Some research and enhancement initiatives have been implemented,
with information from these now being available.
With regard to sustainably managing the eel fishery into the future, the 1996 South
Island Eel Management Plan had no set expiry date. However, with the introduction
of eels into the QMS, and the disbanding of the Regional Eel Management
Committees, much of the 1996 Plan’s purposes have been fulfilled. The South Island
eel industry is now faced with new challenges.
A large body of information is now available from the QMS catch data, and research
and enhancement initiatives generated by the original Plan. It is therefore considered
prudent to revisit the planning provisions for the South Island eel fishery from an
“industry perspective”, in the form of this Industry Plan. It is expected that this Plan
will provide more comprehensive policies for the management of the commercial eel
fishery in the South Island.
Therefore, this Plan provides a management regime for commercial eeling in South
Island waterways. This will provide a mechanism for sustaining and enhancing the
commercial fishery; while allowing for the conservation of freshwater ecosystems
where they are not already compromised by external factors (such as hydroelectric
power development).
In addition, various Codes of Practice are provided to ensure commercial fisheries are
working to maximum efficiency and effectiveness, and that the waterways are not
adversely affected through these activities. For example, a Code of Practice to
prevent didymo is needed to ensure that this serious pest is not spread by commercial
This Eel Industry Management Plan has been prepared by the South Island Eel
Industry Association (SIEIA).
South Island Eel Industry Association: Eel Management Plan September 2009
This South Island Eel Industry Plan (the Plan) directly addresses all the main issues
relevant to the management of the South Island freshwater eel fishery, including the
short-finned eel (Anguilla australis) and the long-finned eel (Anguilla dieffenbachii).
A third species, the Australasian longfin (Anguilla reinhardtii), identified in 1996, has
been confirmed from North Island landings. This species is only rarely encountered
in South Island landings.
The principal objective of this Plan is to ensure the sustainability of the South Island
eel fishery. This Plan is correspondingly concerned with the principals and policies of
the Fisheries Act, as they relate to the utilisation of the fisheries resources in a
sustainable manner. The Fisheries Act principals are outlined in Part 2, as follows:
Part 2
Purpose and principles
8 Purpose
(1) The purpose of this Act is to provide for the utilisation of fisheries resources
while ensuring sustainability.
(2) In this Act—
Ensuring sustainability means—
(a) Maintaining the potential of fisheries resources to meet the reasonably
foreseeable needs of future generations; and
(b) Avoiding, remedying, or mitigating any adverse effects of fishing on the
aquatic environment:
Utilisation means conserving, using, enhancing, and developing fisheries resources to
enable people to provide for their social, economic, and cultural wellbeing.
It is therefore a requirement of the Fisheries Act that the eel resource be utilised to
provide for wider community wellbeing. “Sustainability” is defined as not only the
ongoing maintenance of the eel resource, but also preventing adverse effects on the
environment occurring as a result of resource utilisation.
2.1 Marine Stewardship Council (MSC)
With reference to the requirement in the Fisheries Act for “sustainability” of the
resource, the South Island Eel Industry Association takes its core policy from the
Marine Stewardship Council (MSC), an international organisation with a set of
Principles and Criteria for sustainable fishing. These Principles and Criteria were
It is SIEIA Policy that all commercial eel fishing be conducted in compliance
with the Fisheries Act, the Quota Management System (QMS), and all legal
and administrative requirements
South Island Eel Industry Association: Eel Management Plan September 2009
developed by means of an extensive, international consultative process through which
the views of stakeholders in fisheries were gathered. The Principles reflect a
recognition that a sustainable fishery should be based upon:
1. The maintenance and re-establishment of healthy populations of targeted species;
2. The maintenance of the integrity of ecosystems;
3. The development and maintenance of effective fisheries management systems,
taking into account all relevant biological, technological, economic, social,
environmental and commercial aspects; and
4. Compliance with relevant local and national laws and standards and international
understandings and agreements.
The Principles and Criteria are further designed to recognise and emphasise that
management efforts are most likely to be successful in accomplishing the goals of
conservation and sustainable use of marine resources when there is full co-operation
among the full range of fisheries stakeholders, including those who are dependent on
fishing for their food and livelihood.
Given that the Fisheries Act requires the sustainable utilisation of the freshwater eel
resource, it should be recognised that there is considerable potential to enhance the
resource, and provide for increases in eel quota and seasonal adjustments. This Plan
explores mechanisms for achieving these goals.
This Plan addresses these issues in the light of the long term sustainability of the
fishery, through the QMS management system, and other legal and administrative
requirements. The Plan also addresses issues relating to customary and recreational
harvesters, other water users, Government Departments, the enhancement of the
fishery, and research requirements.
2.2 Plan Review
This Plan, and the policies contained within, addresses the key issues concerning the
South Island commercial eel fishery. They shall remain in force until the South Island
Eel Industry Association resolves to review or replace them in full, or in part. This
may be done at any time.
3. 1. South Island Quota Management System (QMS)
The South Island eel fishery was introduced into the QMS on 1 October 2000, with
the code ANG (for Anguilla). All eel species (Anguilla spp.) are combined under fish
stock codes ANG 11 to ANG 16. The fishing year extends from 1 October to 30
September except for ANG 13 (Lake Ellesmere/Te Waihora) with a fishing year from
1 February to 30 January (beginning 1 February 2002).
South Island Eel Industry Association: Eel Management Plan September 2009
The present QMS provides the following catch allowances:
• Customary: 107.73 tonnes
• Recreational: 10.79 tonnes
• Commercial: 420.10 tonnes
The Total Allowable Catch (TAC), Total Allowable Commercial Catch (TACC),
Customary and Recreational allowances, are shown in Table 1.
Table 1: QMS allowances (tonnes) for South Island freshwater eels.
Allowance ANG 11 ANG 12 ANG 13 ANG 14 ANG 15 ANG 16
Customary 10.26 10.96 31.26 9.0 30.17 16.08 107.73
Recreational 1.03 1.10 3.13 0.90 30.17 1.61 10.79
TACC 40.00 42.70 121.93 35.10 117.70 62.70 420.10
TAC 51.29 54.80 156.32 45.00 150.85 80.41 538.67
The customary right percentage of 20% of the TAC is the same across all ANG
management areas. While data for the customary and recreational take are not
available, Table 2 provides commercial TACC landings since the QMS was
established in 2000. TACC landings have ranged from 303 tonnes in 2000 to 282
tonnes in 2004, with a small decline over this period. This is approximately 70% of
the 420 tonne TAC allowance for commercial eeling.
Table 2: South Island eel catches 2000 - 2008
South Island Eel Industry Association: Eel Management Plan September 2009
The reasons why the commercial catches are less than the TAC are varied. Reduction
in eel stocks is not a reason, as catch per unit effort (CPUE) is improving, indicating
that the eels are becoming easier to catch, and hence more plentiful. Access to
waterways has declined in some areas as a result of Occupational Safety and Health
regulations, and a general reluctance by rural landowners and Government agencies
(such as the Department of Conservation) to allow commercial activities on their
properties. Other reasons include:
1. A number of quota holders have purchased quota for their capital value, rather than
for their harvest value. Hence, they are not fully utilising their harvest.
2. Overseas eel markets, and subsequent prices for South Island eels, have not been
sufficient to encourage full harvest of existing stocks.
3. A number of mataitai areas have been gazetted, and some waterways have been
gazetted as National Park or Reserve. These areas do not normally allow commercial
eel fishing.
3.2 Commercial Catch Levels
Eel catches are greatly influenced by water temperature, flood events (increased
catches) and drought conditions (reduced catches). Shortfins are opportunistic feeders
and are easily caught in flood conditions. This allows fishers to take more shortfins as
part of their quota, when weather conditions allow. The catch declines in winter
months (May to September), particularly in the South Island, where fishing ceases.
Commercial catch data is available from 1965 (from different sources). Catch data by
calendar year is given in Appendix 1. These data reveal a rapid increase in catches
during the late 1960s, with catches rising to a peak of 2077 tonnes in 1972. Landings
were relatively stable from 1983 to 2000, a period when access to the fishery was
restricted but overall catch limits were not in place.
Annual catches have reduced since 2000 to under 1000 tonnes, as eel stocks were
progressively introduced into the Quota Management System (QMS). Appendix 1
provides catch data to 2004-05. Commercial eel quota have been largely under-caught
in all South Island Quota Management Areas, with the exception of ANG 13 (Lake
Ellesmere/Te Waihora), which was 100% caught in 2003–04, 2004–05, and 2005–06.
The combined South Island commercial catch (420 tonnes) has been between 65 and
75% caught over the last six years.
SIEIA intends to ensure that the productive capacities of the eel resource is
maintained at high levels, and is not sacrificed in favour of short term or sectoral
South Island Eel Industry Association: Eel Management Plan September 2009
interests. MSC criteria have been identified which define the means of sustaining a
fishery resource. Principle 1 states:
A fishery must be conducted in a manner that does not lead to over-fishing or
depletion of the exploited populations and, for those populations that are depleted, the
fishery must be conducted in a manner that demonstrably leads to their recovery
The intent of this principle is to ensure that the productive capacities of resources are
maintained at high levels. MSC criteria for fulfilling this principal are:
1. The fishery shall be conducted at catch levels that continually maintain the high
productivity of the target population(s) and associated ecological community relative
to its potential productivity.
2. Where the exploited populations are depleted, the fishery will be executed such that
recovery and rebuilding is allowed to occur to a specified level consistent with the
precautionary approach and the ability of the populations to produce long-term
potential yields within a specified time frame.
3. Fishing is conducted in a manner that does not alter the age or genetic structure or
sex composition to a degree that impairs reproductive capacity.
The principal objective of this Plan is to ensure the sustainability of the South Island
eel fishery. Monitoring of the eel fishery is vital to achieving this goal. The two main
monitoring methods used are catch-per-unit-effort (CPUE) and elver recruitment.
Individually, these methods are not particularly robust, but collectively these methods
can show robust trends. Over time, the two databases will improve. Of particular
interest is where both monitoring methods show the same trend (upwards, stable or
4.1 Catch per unit effort (CPUE)
Beentjes & Dunn (2008) analysed CPUE data from 1991 to 2006. In previous CPUE
analyses, some areas showed a clear trend of declining longfin and shortfin CPUE.
However, other areas showed either no clear trend in CPUE or slight increases. While
shortfin CPUE has remained relatively stable over the study period, longfin CPUE
indicated a slow decline during the period 1991-1999. Both species have recently
shown a marked increase in CPUE in some areas. Beentjes & Dunn (2008) outlined
the nature of these fluctuations:
For the five areas where CPUE for shortfin was considered to be meaningful …, all
showed some indication of increasing CPUE over time. In the West Coast …, CPUE
has increased steadily, whereas in others the recent increase has followed a trend of
decline (North Canterbury, Otago and Southland …). Te Waihora/Ellesmere …
showed an extended flat period followed by a steep increase in the indices since about
SIEIA policy is to use CPUE and recruitment monitoring as the prime
indicators of the sustainability of the South Island Eel fishery. SIEIA shall
provide data wherever necessary to assist in building a robust database.
South Island Eel Industry Association: Eel Management Plan September 2009
2003. The large increase in Te Waihora/Ellesmere was evident both inside and
outside the migration area, although was most overt in the migration area ...
For the four areas where CPUE for longfin was considered to be meaningful, three
patterns are apparent. In the West Coast … the indices fluctuated but with no overall
trend. In Otago and Southland … the CPUE indices declined until about 2000 and
thereafter generally increased. And Te Waihora/Ellesmere … showed a very sharp
decline in longfin CPUE until about 1996, after which it was relatively stable.
NB: The decline in the longfin catch in Lake Ellesmere/Te Waihora is the result of a
SIEIA voluntary code of practice which excludes the targeting of longfins in the
commercial catch.
Since the introduction of eels to the QMS, the TACC has been 67–75% caught each
year. The most recent commercial catch sampling programme for Southland in 2004
showed that mean size of eels from inland river strata were about 5 cm larger than
from the period 1996 to 1998.
Beentjes & Dunn (2008) state that, from their analyses of CPUE data since 1991,
there has been either no trend, a stable eel population, or an increase in eel
populations. Recent increases in CPUE may be a result of recent catch reductions.
Beentjes & Dunn (2008) conclude:
The current analyses for all standalone South Island ESAs from 1991 to 2006 indicate
a general increase in CPUE for both longfin and shortfin since about 2000. For some
areas this represents a reversal of the trend of declining CPUE apparent for the two
previous South Island CPUE analyses. Possible reasons include the recent reductions
in catch following the introduction of the South Island eel fishery into the QMS in
Despite this, Beentjes & Dunn (2008) noted that data for some areas was poor and
that resulting calculated indices are unlikely to be a meaningful index of abundance.
They suggested that combining contiguous areas in future analyses may provide the
only means for determining trends from catch-effort data.
It should be noted that CPUE data is, in reality, a measure of “take per unit effort”,
and not “catch per unit effort”. This is because many eels are release unharmed for
various reasons, such as those over 4kg, migratory eels, unmarketable eels etc. There
can be significant differences between the measure of “catch” and “take” per unit
effort. It is considered that measuring actual “catch” per unit effort would be more
accurate than “take” per unit effort, as there would be fewer variables involved.
However, a this stage it is considered that the existing CPUE method is sufficient for
the purposes of monitoring sustainability of the eel fishery.
SIEIA policy is to continue to provide data to MFish and support continued
monitoring of CPUE as an effective tool for monitoring the sustainability of
the commercial eel fishery. Recommendations for improvements to CPUE
monitoring and analyses, outlined by Beentjes & Dunn (2008), are supported.
South Island Eel Industry Association: Eel Management Plan September 2009
4.2 Recruitment
A description of recruitment biology is provided in Appendix 2. Current research on
recruitment is aimed at establishing a time-series of relative abundance of elvers at
key locations in New Zealand where the upstream passage is restricted by hydro
dams. Martin et al (2008) analysed recruitment data from hydro dams throughout
New Zealand. Recruitment was assessed by monitoring trapping and transfer
operations at four main sites (Karapiro, Matahina, Waitaki, and Arnold dams); and
nine supplementary sites (Wilson's Dam, Morrinsville Dam, Wairere Falls Power
Station, Patea Dam, Piripaua Power Station, Mangorei Power Station, Motukawa
Power Station, Waihopai Dam, and Mararoa Weir).
Capture and monitoring procedures have remained consistent at both Karapiro and
Matahina for a number of years so annual catch figures from these sites are reliable
and comparable, and provide the best records to discern trends in annual recruitment.
Records from the other sites monitored are either too short, catches too low or records
too inaccurate to be used for trend analysis. However, recruitment data should
continue to be taken from these sites for future comparisons to be made.
There are now 13 years of reliable records for Karapiro dam, and nine for Matahina
dam. Overall, the records show large variations in the total catch as well as in the
number of shortfins and longfins captured.
In 2007–08, the total elver catch was over 2-fold greater than the previous season, and
the largest total catch ever recorded. Large increases occurred at Matahina, Karapiro,
Arnold, and Waitaki. Despite the exceptionally large recruitment of longfins noted
for the 2007–08 season at Karapiro and Matahina, there appears to be no significant
long-term trend to longfin recruitment at both Karapiro and Matahina since the
1995–96 season. However, since about 2000–01, annual recruitment of longfin
elvers although variable, has tended to increase (Martin et al 2008).
Shortfin catches at Karapiro show a trend of increasing recruitment since 1995–96. At
Matahina, although shortfin recruitment appeared to be in decline since 2002–03, the
2007–08 catches have reversed the trend. Recruitment of shortfin elvers appears to
have been increasing since 1995–96, and the 2007–08 catch is also about 2-fold
greater than any previous season's catch from the monitored sites (Martin et al 2008).
Martin et al (2008) recommend that recruitment monitoring should continue to be
undertaken from at least 1 December through to at least 15 March at the four main
sites (Karapiro and Matahina in the North Island, Waitaki and Arnold Dam in the
South Island). Because of the variability and subsequent unpredictability of the
timing of the migration period, a longer monitoring period should be considered at
these sites if required. The traps should be operated over the entire season and not
SIEIA supports the continuation of elver recruitment monitoring, and its
application as a tool for monitoring the sustainability of the eel fishery.
Recommended improvements to this monitoring (by Martin et al [2008]) are
South Island Eel Industry Association: Eel Management Plan September 2009
4.3 Conclusion
Currently, both CPUE and recruitment data show that South Island shortfin and
longfin populations are either stable or increasing. As both monitoring methods show
the same general trends, it is concluded that the present level of fishing is consistent
with a sustainable fishery and therefore this level of fishing should continue.
The MSC principal 1, Criteria 2 states:
Where the exploited populations are depleted, the fishery will be executed such that
recovery and rebuilding is allowed to occur to a specified level consistent with the
precautionary approach and the ability of the populations to produce long-term
potential yields within a specified time frame.
Overall, there is evidence that the current status of shortfin eel stocks are not
compromised by commercial fishing. Historically however, factors such as reduced
water quality, water abstraction and lowland stream/wetland modification have
seriously affected shortfin eel stocks.
Similarly, a decline in longfin stocks is documented (e.g. Jellyman 2008), but
commercial fishing is often misidentified as the principal agent of that decline.
Recent studies (see Graynoth et al 2008) show that the principal agent of decline has
been hydro development. Reduced water quality, water abstraction and
stream/wetland modification have also contributed to this decline. Commercial
fishing for longfins might have exacerbated earlier declines in longfin populations,
but recent CPUE and recruitment monitoring indicate that this trend is reversing as a
result of the imposition of the QMS. The existing populations of longfins are
therefore able to be sustainably harvested.
Graynoth et al (2008) estimated the biomass of longfin eel stocks in New Zealand
rivers using modelling techniques, and correlated this to the amount of fished and
unfished waters in the country. Their findings include:
About 7% of the present tonnage of longfin eels is in waters that are closed to
commercial fishing and have safe egress for migrant females. Another 17% is in
waters that are protected in their upper reaches but where migrant females could be
fished downstream, and a further 25% is located in small streams that are rarely
fished. Therefore about 49% of the total tonnage of eels either in reserves or in
streams that are rarely fished.
It is SIEIA policy to continue to maintain the present levels of fishing as
outlined in the QMS, when CPUE and recruitment monitoring indicate stable
or increasing eel populations. This recommendation is to be reviewed on an
annual basis.
South Island Eel Industry Association: Eel Management Plan September 2009
The nationwide “unfished” figure of 49% can be translated into 59% for the South
Island and 41% for the North Island (see Figure 1).
Graynoth et al (2008) also state that waters open to commercial fishing support an annual
harvest rate of about 7.8%. Furthermore, their report states:
Hydro dams have reduced eel access to waters that could support over 6000 tonnes of
longfin eels.
A standing crop of 6000 tonnes could sustainably support the entire South Island
TACC. Therefore, SIEIA rejects assertions that past declines in longfin eel stocks are
the result of unsustainable commercial fishing. Changes in recruitment for longfin
eels due to a reduction in population size take many years to manifest themselves. It
is likely that the decline in NZ longfin stocks was principally the result of large hydro
developments on the Waitaki, Clutha, Waiau, Waikato and Matahina catchments (and
many smaller catchments) over the past 40 years.
The longfin eel has been classified as in “gradual decline” following a review of the
threat status of native flora and fauna undertaken by the Department of Conservation.
This classification was undertaken by the Department as a result of discussions
between various Department of Conservation staff, scientists and MFish staff. SIEIA
was not involved in this exercise in any way. This was unfortunate, as SIEIA has a
large capital stake in quota value of the fishery. SIEIA members risk losing much of
this value if public waterways are closed to commercial eeling as a result of the
reclassification of longfin eels as “threatened”.
The “gradual decline” classification for longfins is the lowest threat ranking, and
indicates an expected decline of 5-30% over the next ten years and into the future if
current threats continue. There is no threat of extinction. Factors leading to the
classification were the data suggesting poor recruitment in some years, fishing
pressure, loss of habitat and the implications of a sex ratio bias in one area of the
South Island. The combination of these factors is thought to place the species at risk
of decline.
This threat ranking is presently being reassessed by the Department of Conservation.
Given the results from CPUE and recruitment monitoring, it is expected that longfins
will have their threatened status removed. The introduction of all New Zealand eel
fisheries into the QMS, with consequent reductions in catch levels, improved CPUE
figures and improved elver recruitment, would indicate that the threat status for
longfin eels has been reduced.
SIEIA rejects assertions that commercial fishing, undertaken on a sustainable
basis under the QMS and in accordance with this Plan, causes a chronic
decline in longfin populations, or otherwise threatens existing eel stocks
(shortfin and longfin) in any way.
South Island Eel Industry Association: Eel Management Plan September 2009
Figure 1: Areas of Conservation land that are closed to commercial eel fishing
(black), or open (grey). White is other land ownership. (from Graynoth & Booker
MSC Principal 1, Criteria 3 requires the following:
It is SIEIA policy to require its involvement in any reclassification of the
status of shortfin and/or longfin eels; and require DoC to notify SIEIA of any
such exercise at the early planning stage.
It is current SIEIA policy to call for the removal of longfin eels from their
“threatened” status.
South Island Eel Industry Association: Eel Management Plan September 2009
Fishing is conducted in a manner that does not alter the age or genetic structure or
sex composition to a degree that impairs reproductive capacity.
As eels are harvested before spawning, the escapement of sufficient numbers of eels
to maintain a spawning population is essential to maintain recruitment. Egg
production per recruit, or spawning per recruit, is vulnerable to exploitation of the
adult stock, since eels breed only once and at a very-advanced age. For shortfin eels
the wider geographic distribution of this species means that spawning escapement
occurs from a range of habitats throughout its range. In contrast, the more limited
distribution of longfin eels means that the spawning escapement must occur from
New Zealand freshwaters and offshore islands only.
Based on GIS modelling it has been established that for longfin eels, 5% of habitat
throughout New Zealand is in water closed to fishing where there is protected egress
to the sea to ensure spawning escapement. A further 10% of longfin habitat is in
areas closed to fishing in upstream areas but where the spawning migration could be
subject to exploitation in downstream areas. However, migrant longfins are not
harvested, as SIEIA has imposed a voluntary ban on the targeting of migrant adult
longfin eels.
Biomass estimates of migrant longfin females in reserve and rarely-fished or unfished
areas suggest that these areas are sufficient to maintain present longfin stocks but
insufficient to maintain recruitment for historical stock levels. However the
modelling does not take into account habitat reductions caused by hydro development
and habitat loss. If these factors are included, it is estimated that the current biomass
of longfin eels above the minimum weight at migration is less than 20% of historical
6.1 Upstream elver transfer
The transfer of elvers and juvenile eels to catchments above artificial barriers
(especially hydro dams), has been established as a practical method of enhancing eel
populations, and increasing productivity in areas where recruitment has been limited.
Elver transfer operations are conducted in summer months when elvers reach river
obstacles on their upriver migration.
Several projects have been undertaken to evaluate the enhancement of depleted
customary fisheries through the transfer of juvenile eels. In 1997, 2009 juvenile eels
(100–200 g) were caught from Lake Ellesmere/Te Waihora, tagged and transferred to
Coopers Lagoon a few kilometres away. Only ten tagged (coded wire tag implanted in
the top of the head) eels, all females, were recovered in 2001. It is likely that a large
SIEIA members shall continue with the ban on targeting migrant longfin eels.
South Island Eel Industry Association: Eel Management Plan September 2009
number of eels migrated to sea as males following the transfer. Another project in
1998 transferred 7600 (21% tagged) eels weighing less than 220 g from Lake Waahi
in the Waikato catchment to the Taharoa Lakes near Kawhia. No tagged eels were
recovered when the lakes were surveyed in 2001. It is considered that a large number
of eels migrated from the lake as males following the transfer.
The conclusion from these two transfers is that transplanted eels need to be females,
requiring that eels larger than 220 g and above the maximum size of migration for
shortfin males need to be selected for transfer.
In 1998 approximately 10000 juvenile eels were caught in the lower Clutha River,
tagged and transferred to Lake Hawea. In 2001, 19.4% of the tagged eels were
recovered. An estimated 80% of transferred eels survived after three years. The
transferred eels showed accelerated growth and the mean annual growth in length was
almost double that of eels from the transfer site.
For upstream elver passage, retro-fitted native fish passes have previously been shown
to be ineffective. Therefore, the “catch and carry” system is presently the preferred
method of eel enhancement. However, SIEIA has significant concerns about current
“catch and carry” systems for the following reasons:
1) Elvers do not always congregate at the same place as other native fish (e.g.
whitebait). Therefore, any elver “catch and carry” system may need to be
independent of other fish passage systems.
2) Elvers do not always congregate at the same site each year. Also, not all elvers are
attracted to the same point at the bottom of a dam, so only a proportion of migrating
elvers will be able to be caught for transfer. Therefore, the catching system would not
be able to be installed at a fixed site.
3) Fish congregating at the bottom end of the dam will be exposed to additional
mortality factors, especially predation by larger fish and seabirds. This has been
observed at other dams where elvers have congregated because their upstream
migration has been blocked.
4) SIEIA has virtually no information on elver survival after transfer, other than the
Clutha/Hawea juvenile transfer (see above). In addition, SIEIA has no information on
whether elver survival is affected by moving elvers from a flowing-water habitat
immediately into other habitats such as lakes or wetlands.
5) Exposure to mortality factors such as disease and predation as a result of the
transfer process could be significant.
Present “catch and carry” systems are largely funded through hydro-electricity
companies’ compliance with the conditions on their resource consents to dam the
river. While compliance with consent conditions has been effective, SIEIA regards
much of this as a “box-ticking exercise”, with little regard for the end result (in
relation to enhancement of upstream eel populations). This results in ineffective eel
At present, elver “catch and transfer” systems are preferred over retrofitted
native fish passes, for eel enhancement upstream of dams.
South Island Eel Industry Association: Eel Management Plan September 2009
enhancement measures, despite the dams seriously damaging the fishery. Much of
these problems originate from inexperience, and unawareness of the difficulties
outlined in 1-5 above.
Accordingly, SIEIA will seek closer involvement with existing “catch and carry”
systems, and require its involvement in new systems, through ongoing consultation
with dam owners and input into resource consent conditions. Further information is
provided in Section 8.10.
6.2 Downstream migrating transfer
A significant problem occurs where downstream migrating eels cannot pass through
barriers such as dams and weirs. This problem is compounded by the fact that few
eels survive passage through hydro-electric turbines. This means that any spawning
contribution from eels living above these dams is lost.
To mitigate the impact of hydro turbines on migrating eels, a catch and release
programme for large longfin females has been conducted from Lake Aniwhenua with
release below the Matahina Dam since 1995. A capture and release programme has
also been conducted from Lake Manapöuri to below the Mararoa Weir on the Wairau
River, Southland by the Waiau Mahinga Kai Trust, since 1998. Adult eel bypasses
have been installed at the Wairere Fall power station on the Mokau River since 2002
and controlled spillway openings have been undertaken at Patea Dam during rain
events in autumn (when eels are predicted to migrate downstream) since the late
The problem with these measures is that their effectiveness in passing migrating eels
unharmed is difficult to measure. Not all eels can be captured and safely transferred,
and the adverse effects on their spawning cannot be measured. The best that can be
done is to trap adult migrating eels from above dams and release them downstream.
SIEIA has the necessary expertise to undertake this task. For example, SIEIA
members regularly trap and transfer migrating shortfin and longfins across the gravel
bar at Lake Ellesmere/Te Waihora. These operations have successfully transferred
many tonnes of migrating eels, and local knowledge amongst commercial fishermen
has built up over the years, allowing the timing and methods of trapping migrating
eels to be optimised.
Therefore, where necessary and practicable, migrating eels shall be caught and
released downstream of any dam acting as a barrier to adult migration. These eels
will hopefully remain downstream of the structure until they reach spawning
conditions, and then pass safely out to sea.
It is SIEIA policy to be fully involved with all existing and new elver
enhancement programmes required through resource consent conditions.
This involvement will include planning, field work and monitoring elver
enhancement systems, at the expense of the consent holder.
South Island Eel Industry Association: Eel Management Plan September 2009
MSC Principle 2 requires the following:
Fishing operations should allow for the maintenance of the structure, productivity,
function and diversity of the ecosystem (including habitat and associated dependent
and ecologically related species) on which the fishery depends.
The intent of this principle is to encourage the management of fisheries from an
ecosystem perspective under a system designed to assess and restrain the impacts of
the fishery on the ecosystem.
Criteria required to meet this principal are:
1. The fishery is conducted in a way that maintains natural functional relationships
among species and should not lead to trophic cascades or ecosystem state changes.
2. The fishery is conducted in a manner that does not threaten biological diversity at
the genetic, species or population levels and avoids or minimises mortality of, or
injuries to endangered, threatened or protected species.
3. Where exploited populations are depleted, the fishery will be executed such that
recovery and rebuilding is allowed to occur to a specified level within specified time
frames, consistent with the precautionary approach and considering the ability of the
population to produce long-term potential yields.
This section addresses these criteria in detail. In addition, Section 9 outlines measures
designed to ensure that New Zealand’s freshwater biosecurity is not compromised by
commercial eel fishing operations.
7.1 Other Sources Of Mortality
There is no information on the level of fishing related mortality associated with the
eel fishery. The fishing methods used in the fishery are passive and catch eels in a
live state. However eels are subject to significant sources of mortality due to nonfishing
activities. The actual mortality from non-fishing activities has not been
quantified. Direct mortality occurs through the mechanical clearance of drainage
channels and damage by hydro-electric turbines and flood control pumping.
Hydroelectric turbine mortality is affected by eel length, turbine type and turbine
rotation speed. The turbine mortality of larger eels (specifically longfin females), is
When fishing upstream of any dam acting as a barrier to adult migration,
SIEIA members shall release, downstream of this barrier, all migrating eels.
It is SIEIA policy that the cost of this transfer is borne by the dam consent
South Island Eel Industry Association: Eel Management Plan September 2009
thought to be 100%. Given the large area of water in hydro lakes, this source of
mortality could be significant and prevents spawner escapement.
In addition to these direct sources of mortality, eel populations are likely to have been
significantly reduced since European settlement in the 1840’s by wetland drainage
(wetland areas have been reduced by up to 90% in some areas), and habitat
modification brought about by the channelisation of rivers and streams and the
reduction in littoral habitat. On-going drain maintenance activities may similarly
cause problems for the survival of eels.
These issues are discussed in more detail in section 8 of this Plan.
7.2 Illegal catch
There is no information available on illegal catch. There is some evidence of fishers
exceeding the amateur bag limit, and some historical incidences of commercial fishers
operating outside of the reporting regime, but overall the extent of illegal take is
considered to be not significant.
Despite this, illegal takes have the potential to cause significant damage to the
sustainability of the fishery. This has been demonstrated in other New Zealand
fisheries (e.g. paua). Preventing illegal takes, along with education of recreational
fishers are important activities in avoiding damage to the fishery.
7.3 Yield-per-recruit
Yield-per-recruit (YPR) models have been run on Lake Ellesmere/Te Waihora and
Lake Pounui, to test the impact of increases in size limit. Results indicate that an
increase in minimum size should result in a small gain in YPR for shortfins in Lake
Ellesmere/Te Waihora and longfins in Lake Pounui, but a decrease for shortfins in
Lake Pounui.
A practical demonstration of the benefits of an increase in size limit has been reported
from the Waikato area where a voluntary increase in minimum size from 150 to 220 g
in 1987 resulted in decreased CPUE for up to 18 months, but an increase thereafter.
Yield per recruit will need to be maximised in circumstances where recruitment is
limiting. Current recruitment monitoring reveals that this is improving, although it is
likely that it could improve further. Therefore, it is preferred that yield per recruit is
Current regulations require eels of less than 220g to be released unharmed. This is
normally achieved through the use of 27mm escapement tubes (which are rated to
SIEIA members shall report any actual or potential illegal eel fishing to the
Ministry of Fisheries as soon as practicable.
South Island Eel Industry Association: Eel Management Plan September 2009
allow eels of 220g or less to escape). However, during floods, smaller eels can gorge
themselves on worms etc, making them larger than 220g. When caught, they then
disgorge this food, bringing them back below the 220g limit. Therefore, in the South
Island, escapement tubes have been enlarged to 31mm, to allow eels of 280g or less to
escape. This overcomes the problem of smaller eels being caught, and enhances the
yield per recruit.
7.4 Sex ratio
The shortfin fishery is based mainly on the exploitation of immature female eels,
although there is a significant fishery based on migrant male eels in Lake
Ellesmere/Te Waihora. Elsewhere, male shortfin eels migrate before reaching the
minimum size of 220 g and are therefore not harvested. This allows sufficient male
shortfins to escape from other waterways to breed; which compensates for taking
migrating male shortfins from Lake Ellesmere/Te Waihora.
The longfin fishery is based on immature male and female eels. A study on the
Aparima River in Southland focused on assessing the longfin spawning escapement
from a fished area of the mainstem river and lightly fished areas of tributary streams.
The study found that female longfins were rare in the catchment. Only five of 738 eels
sexed were females. This is presumably because the chances of the longer-lived
females being caught are proportionately greater.
The sex ratio in other southern catchments, determined from analysis of commercial
landings, also show a predominance of males. In contrast some other catchments
(Waitaki River, some northern South Island rivers) showed approximately equal sex
ratios. The presence of skewed sex ratios in some waterways is not thought to have
any significant adverse effect on breeding success or recruitment into the eel fishery.
Explaining the predominance of males in some rivers, but not others, should not be
attributed directly to the effects of fishing. Other factors affecting sex rations include:
• The sexual differentiation of eels can be influenced by environmental factors. It is
possible that changing environmental factors are responsible for the greater
proportion of male eels in these southern rivers.
• Male and female eels may have different behaviour in different waterways,
depending on a wide range of environmental factors. This may cause different
male/female sex ratios in the catch.
• Commercial fishermen do not target longfin eels > 4kg. These are all female.
Therefore, it is likely that more males would be caught in areas where habitat for
> 4kg eels is not present.
SIEIA members shall continue to use 31mm escapement tubes which allow eel
of 280g or less to escape unharmed from their nets.
South Island Eel Industry Association: Eel Management Plan September 2009
7.5 Shortfin/Longfin Ratio
ANG eel quota does not differentiate between longfin and shortfin eels. This allows
flexibility for fishers to mix their catch ratio between the two species according to
local conditions and availability. For example, shortfin eels can be easier to catch
during flood conditions. It is important that the ratio of shortfins and longfins in the
catch is not fixed by the QMS, so that fishers are able to take advantage of favourable
conditions, in order to fulfil their quota in the most efficient and effective manner
It is SIEIA policy that the QMS does not differentiate between shortfin and
longfin eels in the TACC
Fishers have currently preferred to target shortfin eels over longfins. Shortfins are
generally faster-growing than longfins, and easier to access as they generally favour
lowland waterways. This preference for estuaries and lowland waterways makes
shortfin eels less prone to the impacts of hydro dams and other migration barriers.
All South Island ANG regions have at least 20% of the available fishing habitat as
predominantly shortfin habitat. Therefore, it is preferred that at least 20% of the
TACC from each region consists of shortfins, although this may be considerably more
in some regions. For example, the Lake Ellesmere/Te Waihora Region is a 100%
shortfin fishery.
It is SIEIA policy that at least 20% of the TACC in each South Island ANG
Region consists of shortfin eels
7.6 Trophic cascade
Trophic cascade is defined as an adverse shift in ecosystem dynamics caused by the
removal of link(s) in the food chain through depletion of fish stocks. Eels occupy the
higher end of the food chain, with smaller eels (< 300g) being predominantly
insectivorous, and eels > 300g being both insectivorous and piscivorous. Larger eels
> 2 kg can become predominantly piscivorous.
The excessive removal of eels from a waterway therefore has the potential to cause
trophic cascade, through removal of a high-end predator. However, larger eels > 4kg
are released unharmed, so the piscivorous character of the food chain is largely
retained. Insect communities are unlikely to be changed as a result of the harvest of
smaller eels. Furthermore, introduced brown and/or rainbow trout are widespread
and common in almost all major NZ waterways. These species are likely to have an
equivalent or greater effect on high-end trophic relationships than eels.
Therefore it is considered that the threat of trophic cascade is not a factor in the
sustainable harvest eels in NZ waterways.
South Island Eel Industry Association: Eel Management Plan September 2009
7.7 Minimum Quota holding
Currently, there is a 4-tonne minimum holding for ANG quota in the South Island.
This was imposed because it was thought that it would bring efficiencies to the
commercial fishing of eels through reducing the number of small, part-time fishers.
However, this rule restricts the ability for trading ANG quota to new entrants who
may wish to start small, without having to commit considerable capital to purchase
quota, before they even start fishing. It also has the effect of reducing the
marketability of ANG quota, reducing its value and generally distorting the value of
eel quota. This rule makes no difference to the sustainability of the eel fishery, and
there is no practical reason for it to remain
It is SIEIA Policy for the 4 tonne minimum quota holding requirement, for
South Island ANG quota, to be removed from Schedule 8 of the Fisheries Act.
7.8 Summary of measures to maintain a sustainable fishery
In summary, SIEIA initiatives to improve the sustainability of the fishery will
continue. These include:
• Escapement tubes of 31mm to allow juvenile eels to escape from nets. This
significantly improves the yield-per-recruit;
• A 4kg upper size limit to protect breeding females;
• A code of practice to prevent the taking of migrating female eels.
• Accurate reporting of catch data for ongoing monitoring of eel populations.
• A policy that at least 20% of the TACC in each South Island ANG Region
consists of shortfin eels.
The sustainability of the eel fishery is dependent on the sustainability of the habitat,
and how it is managed. There have been a large number of pressures put on eel
habitat, principally in lowland waters of the South Island. These pressures are
principally caused by increased nutrient inputs from the dairy industry, and excessive
abstraction of waterways through irrigation development.
Issues requiring management include flood control works, obstacles to eel migration
(upstream and downstream), drain clearance, general discharges and biosecurity.
8.1 Discharges
Regional Councils manage point-source and non point-source discharges, through the
Resource Management Act and associated Regional Water Plans. These Plans are
South Island Eel Industry Association: Eel Management Plan September 2009
updated from time to time. Consultation on Regional Water Plan development is
essential to ensure that eel habitats are not compromised. Regional Councils are
charged with obtaining monitoring and compliance information on discharges. This
information should be forwarded (on request) to the SIEIA, to ensure that eel fisheries
are not adversely affected by excessive pollution. In addition, any accidental
pollution incident needs to be immediately reported to the SIEIA.
Pollution from non-point discharges includes all harmful changes in water quality
caused by the diffuse discharge of toxic substances into the waterway from the
surrounding lands. These may include excess heat, salinity, silt, pesticides, oxidising
agents and oxygen consuming materials. The effects of these can range from subtle
alteration of the instream habitat to the detriment of eel stocks, to the direct mass
deaths of eels and other fish. Further problems are encountered through the
contamination of eel flesh.
Management of non-point source pollution of waterways requires a close relationship
between SIEIA and territorial authorities (Regional and District Councils). In
particular, proposed Regional and District Plan changes will need to be closely
scrutinised to ensure their provisions do not adversely affect water quality, through a
permissive attitude towards non-point discharge activities (e.g. subdivisions). SIEIA
shall assist Councils in the promotion of statutory Plans and catchment management
Plans; which may be developed to assist in improving water quality, particularly for
Waihora/Lake Ellesmere.
SIEIA shall also advocate that territorial authorities:
a) Identify priorities for enhancement of water quality, including research
b) Set as a minimum environmental standard the maintenance and
enhancement of water quality in waterways.
c) Apply monitoring and enforcement procedures to ensure pollution from
non-point source discharges is minimised.
d) On request, provide SIEIA with information from water quality monitoring
and research.
South Island Eel Industry Association: Eel Management Plan September 2009
8.2 Land Use
Water quality (and consequently eel habitat) can be adversely affected through
changes in land use, especially the felling of native or exotic forests, and intensive
agricultural development. An objective of this Plan is to minimise the adverse effects
of these changes on eel habitat.
The felling of native and exotic forests can significantly change the character of the
eel habitat. A forest canopy shades the water, providing generally cooler and more
stable water temperatures. Nutrients are captured by the vegetated riparian margins
and erosion rates are generally slower. Branches and logs in the waterway can
provide additional habitat for eels and their prey. The effects of shading on algal
masses and aquatic weeds is beneficial for eels.
Agricultural development of catchments has resulted in marked changes in stream
ecology, especially in lowland streams. These are the most productive areas for eels,
especially shortfin, so these effects have been significant. Pollution from point and
non-point discharges, channelization’s and stop-banking, sediment inputs, wetland
drainage and riparian vegetation change have all contributed to the serious
degradation of eel habitat in agricultural areas.
The recent popularity of dairy farming, especially in lowland areas, has the potential
to seriously affect eel habitat. Horticultural development in the South Island (e.g.
vineyards) is also very popular, but can have serious effects on water quality if not
properly managed. SIEIA will liaise with industry representatives on the
development of guidelines and oversight of Codes of Practice which minimise the
impact of agricultural development on eel habitat.
SIEIA policy is that it shall:
1. Advocate for no direct discharge of contaminants to waterways, except
where this may to enhance the habitats of those waterways (e.g. for
biosecurity purposes).
2. Request that SIEIA is informed whenever an accidental pollution event
4. Advocate that Regional Councils, through the Regional Planning
a) Set as a minimum environmental standard the maintenance and
enhancement of water quality through the strict regulation of point
source discharge in accordance with MFE water quality guidelines.
b) Identify priorities for enhancement of water quality through the
regulation of point-source discharges
5. Promote industry-based “polluter pays” research into point-source
discharges and the effects they have on water quality.
South Island Eel Industry Association: Eel Management Plan September 2009
8.3 Agrichemicals and fertilisers
Pesticides, herbicides and animal remedies are used throughout New Zealand to
improve agricultural productivity. Some of these compounds are highly toxic and can
bioaccumulate through the food chain. Eels are a high-end predator in the food chain,
so are more likely to bioaccumulate toxic compounds than other instream species.
Anthelminthic drenches and pour-on formulations for stock parasites are one of the
most insidious groups of chemicals which can find their way into waterways. Animals
excrete these chemicals in their urine, and through soil runoff they can remain toxic to
aquatic invertebrates. For example, “Southland Plains Syndrome” was coined to
describe the complete absence of aquatic insects in some waterways on the Southland
Plans, in the 1970’s. This was later found to be largely caused by sheep dips and other
animal remedies being discharged into these waterways.
SIEIA policy is that it shall:
1. Liaise with Fonterra and other agricultural industry representatives to
ensure that Codes of Practice are developed and implemented, which
ensures that agricultural development does not adversely affect eel
2. Encourage better forestry practices which ensure that forestry
operations do not adversely affect eel habitat. These may include:
a) Methods for ensuring that eel habitat is not damaged during the
harvesting of exotic forests. These need to be encouraged as far as
b) Where exotic forests are not being replanted (e.g. for dairy
conversion), riparian plantings should be established to ensure that
no long-term damage is done to the eel habitat.
c) Methods for protection and conservation of native forests and
tussock land will be encouraged.
4. Encourage better farming practices which ensure that stock do not have
access to riparian margins.
5. Provide advice and support to farmers who are contemplating
agricultural development, either through the resource consent process, or
through individual advocacy, to ensure that eel habitats are not adversely
South Island Eel Industry Association: Eel Management Plan September 2009
Thus, habitat loss for eels can occur with little evidence to show how it is happening,
apart from the presence of stock nearby. It is important that these insidious agents of
habitat loss are halted and reversed to ensure the eel fishery remains sustainable.
The presence of pollutants in the flesh of eels can exclude them from export markets.
This can also affect New Zealand’s “clean, green image”, which would have knock-on
effects for other export foodstuffs. It is important that waterways are not contaminated
with agrichemicals which may bioaccumulate and persist in the flesh of eels.
8.4 Riparian Areas
The riparian margins are the strips of land adjacent water bodies, and may include
berms, stopbanks and floodways. They are the interface between the water body and
dry land. Maintenance and enhancement of riparian areas is a major objective of this
Plan. This is because the riparian area is as a major controller of habitat quality for
eels. It is important for food supply, shelter, bank stability, nutrient control
temperature control and flood control.
Many areas have had their riparian vegetation removed and are now farmed right to
the water’s edge. This has adverse effects on eel habitat and the instream ecosystem.
A well-planted riparian margin increases the storage of water, changes the distribution
of flood flows, decreases flooding downstream, decreases erosion, increases bank
stability, decreases instream sediment load and improves the overall habitat for eels.
The enhancement of the riparian zone is therefore a priority of this Plan.
Different water bodies require different plant species in the riparian zone, and there is
a change in habitat preference and species as you move further away from the
waterway. The preference is for the planting of native species such as flaxes, sedges
and rushes for bank stability. Native species recreate the natural ecosystem and are
SIEIA policy is that it shall:
1. Advocate that:
a) The use of agrichemicals near streams and waterways should
cease, if there is any possibility that they may enter that waterway through
direct or diffuse discharge.
b) If agrichemical use is necessary (e.g. for aquatic weed control),
then only those chemicals which are non-toxic to vertebrates, and do not
persist nor bioaccumulate in the food chain, are used.
2. Advocate for the application of suitable Codes of Practice for the
application of agrichemicals near waterways, through the provision of
advice and support to individual farmers, industry representatives and
territorial authorities through the planning process.
South Island Eel Industry Association: Eel Management Plan September 2009
less obtrusive and simpler to control than many exotics. If exotics must be used then
they should provide shade and bank stabilisation to act as protection for native
plantings, and where possible, should be removed later on.
It is recommended that the following species are used where possible as they are the
most appropriate for riparian planting:
• Flaxes, sedges and rushes should be planted closest to the water. Flax has an
excellent ability to bind the soil on the bank, thus preventing erosion, and
providing habitat amongst the roots. Flaxes are also dense enough to prevent
stock from pushing through them and entering the waterway.
• Shrub willows (pohangina, kumiti, glenmark, tiritea) will also provide bank
stability and shade. They are best situated behind species like flax and raupo on
the slope of the bank because they have larger root systems that stabilise soil.
• On the top of the bank it is best to plant larger native species like kowhai, manuka
and kahikatea. These large trees will provide excellent shade for the water when
they are established. Their large root systems will also stabilise the bank.
It is recognised that removal of trees and their root systems from within the channel is
sometimes necessary for flood control. In some areas willows have become so
prolific that they are a flood hazard. However, willows can provide excellent eel
shelter, and their root systems provide excellent eel habitat. They can also help
stabilise daytime water temperatures through their shading effect. Depending on the
willow species involved, their removal can physically destroys this habitat. Those
species listed above (pohangina, kumiti, glenmark, tiritea) are preferred for future use
in river control systems.
South Island Eel Industry Association: Eel Management Plan September 2009
8.5 Water Abstraction
Water abstraction has the potential to adversely affect eel habitat through habitat loss,
and also through the reduction in upstream and downstream eel passage. The
reduction in summer flows particularly affects eel habitat through elevated water
temperatures and deoxygenation of waterways.
Irrigation demand is increasing, especially in South Island east coast areas, as a result
of the dairying boom. Further demands for water abstraction for hydro-electric power
generation are also being created by the desire to move away from global warminginducing
thermal electricity generation. As a consequence, many waterways have
exceeded an allocation of water which would result in minimal environmental
impacts. In many summers, South Island east coast waterways have dried up and/or
their mouths have closed off, which has serious impacts on eel habitat and elver
migration. The setting of minimum flows is required with a buffer or cap to ensure
the protection of the instream values and sustain residual flows.
There is the potential for mitigating the loss of habitat in waterways through the
enhancement of irrigation canals with eels. Liaison with irrigation companies is
essential to achieve this.
SIEIA policy is that it shall:
1. Encourage District and Regional Councils to place a higher regard on
monitoring and compliance of activities in the riparian area.
2. Advocate that District and Regional Councils restrict development of
any kind within a waterway, or situated on the riverside of flood banks
where flooding will periodically inundate the area.
3. Advocate the exclusion of stock from access into waterways and drains
because of the damage they cause to the substrate and the direct
contamination of the water.
4. Encourage fencing and planting (preferably native plant species or
preferred willow species) of riparian strips to protect the stream bank and
prevent access to the stream by grazing stock.
5. Work with District and Regional Councils and DoC to develop a
programme for restoring the riparian vegetation to its natural state. This
will include the use in riparian plantings of the native plant species
described above.
South Island Eel Industry Association: Eel Management Plan September 2009
8.6 Weed clearance and drainage
The removal of weeds from streams by mechanical diggers has serious detrimental
impacts on aquatic communities, and eels in particular (Young et al 2004). While
aquatic weeds can cause problems with flood control and drainage, there are many
cases where their clearance should not be carried out using mechanical methods. In
particular, mechanical diggers can damage the stream substrate, and result in stream
bank and riparian vegetation damage. Recent advances in chemical weed control now
allow this to be the preferred method of aquatic weed control over the use of
mechanical diggers.
If mechanical control needs to be used, the following guidelines should be promoted:
a) Operators should use a bucket design (e.g. grab buckets) that take only weeds, and
not the substrate.
b) Approved operators should be used wherever possible.
c) Diggers with pressure-sensitive hydraulics should be used as they will cause less
damage to the bed and margins of the waterway.
d) Operators should be educated on the values associated with the waterway so they
respect these when they are clearing them.
e) Selective removal of weeds that impede water flows in drains, such as clearings of
only half-width, alternating sections, or only the weed from the middle of the
waterway, will allow for sufficient remaining habitat for freshwater fish.
f) Debris from clearing is to be removed from the channel to avoid anoxia caused by
decomposition and the clogging of areas downstream.
SIEIA policy is that it shall:
1. Advocate that Regional Councils set sustainable minimum flows in
waterways to ensure that the source of water is not overexploited.
2. Establish policies with local government authorities, landowners,
irrigation and power companies to apply the following guidelines so as to
allow the establishment of eel fisheries in irrigation canals and connecting
a) If a race is accessible to fish then maintenance of a residual flow is
b) Large races that are operating continuously should have provision for
fish passage both in and out.
c) Regional Councils should quantify the amount of water to be abstracted
from waterways and aquifers, to determine a limit on the amount able to be
abstracted at any given time, and so to protect sustainable instream flows
and values in the mainstream and the residual flow in the irrigation
South Island Eel Industry Association: Eel Management Plan September 2009
g) Summer is the best time for any clearing as eels are more active and likely to
h) Monitoring of the clearing activity should be encouraged to ensure that live fish
are released back into the stream.
8.7 Wetland protection and enhancement
Massive losses of eel habitat occurred when swamps were drained for pasture
production. This happened on a grand scale in earlier times, particularly on the East
Coast of the South Island. Wetlands provide excellent eel habitat. Shortfin eels have
adapted specifically to live in wetlands and thrive in this environment. The retention
and enhancement of remaining wetland is therefore important to sustain the eel
The practice of eel fishing does not damage the wetland ecosystem. It is noninvasive,
does not damage other flora and fauna, and can aid the productivity of the
wetland through the sustainable removal of a top predator. Therefore, wetland
protection and enhancement plans should include provision for all forms of eel fishing
(customary, recreational and commercial) as a matter of course.
It is an objective of this Plan to encourage and support the restoration, enhancement
and protection of existing wetlands, and the creation of new wetlands, while ensuring
that this does not impede the ability to harvest eel from these areas
SIEIA policy is that it shall:
1. Support manual and/or approved herbicide control for aquatic weeds in
2. Require the above guidelines to be used for mechanical weed control.
3. Request Regional Councils to publicly notify any instream works
programmes using mechanical methods.
4. Oppose the introduction of exotic fish and plant species for biological
control of weeds e.g. grass carp.
5. Oppose the further lowering of water tables through drainage of
wetlands and rivers.
South Island Eel Industry Association: Eel Management Plan September 2009
8.8 Channelling and flood protection works
The natural process of a river is to meander and flood. These processes are essential
in maintaining the natural diversity of habitats within the waterway. Channelling and
straightening changes the natural character of the waterway to the extent that it is not
as suitable for fish.
Channelling, straightening and stopbanking will lead to increased floodwater flows
and velocities. This leads to increased stream bed and bank erosion through removal
of the armoured stream substrate, and hence may cause a streambed to become
permanently unstable. This streambed instability adversely affects eel habitat.
Floods are an important time for eel feeding. Eels are opportunistic feeders, and
utilise freshly inundated areas during floods as major feeding areas. Stopbanking and
channelling reduces the flooded areas, and also reduces the eel ability to gain access
to them.
There is the potential to recreate a considerable area of waterway by redirecting rivers
down their original path and placing a weir at the beginning of the flood channel to
ensure it is used only during flood events. This will return the river to its natural state
and substantially improve the aesthetic and biological characteristics of the river,
while maintaining flood control capacity.
SIEIA will work with local government authorities to ensure that:
SIEIA policy is that it shall:
1. Participate in planning forums and processes to ensure that eel fishery
values are accommodated in the management of existing and new wetlands.
2. Advocate to DoC, LINZ, landcare groups and territorial authorities to
ensure that wetlands are able to be accessed for the harvesting of eels and
are available for providing food and an area for eels to grow and mature.
3. Maintain and enhance oxbow lake systems that have been isolated
through natural and human-induced processes, as areas for habitat
enhancement. These areas are open to eel recruitment through flooding of
creeks leading to them.
4. Advocate for Regional and District Councils to control activities (such as
drainage and extraction bores closed to recognised wetlands) that may have
an adverse effect on the eel fishery and their habitats.
5. Encourage the creation of wetlands on publicly owned and private
South Island Eel Industry Association: Eel Management Plan September 2009
a) Stabilisation and flood control methods do not disturb the rivers natural channel
are used, and that channelling the waterway is used as a last resort for flood control.
b) Recreated river channels that do not have a uniform shape are supported.
c) Bends in the rivers are preserved as important habitat.
d) If there is a need to construct channels for flood prevention then they are to be dry
channels that only fill when the river rises to a certain point. This may be done by
placing a weir at the start of the channel.
e) Wide fairways are maintained to avoid adverse effects from floods. Constrained
channels are more likely to burst their banks and cause scouring.
f) Where possible, rivers are allowed to flood and not be constrained by channels
and flood banks.
g) If possible, a preference for rock stabilisation of banks. These can provide a stable
substrate that is difficult to move, even in foods. They can also provide shelter for
many fish species.
h) Channelization of smaller streams should be discouraged. There is normally very
little need for this and it can severely affect the instream values
i) SIEIA should be consulted on any application for consent to alter a riverbed, to
ensure the eel fishery and habitat needs are recognised and provided for.
8.9 Gravel and sand removal
This can have adverse effects on eel habitat through general disturbance, increased
turbidity, and removing the armouring of a streambed. It is important that gravel and
sand removal is only from dry areas of watercourse so as to avoid adverse effects on
SIEIA policy is that it shall:
1. Co-operate with local government authorities in the development of
guidelines for appropriate flood management strategies that incorporate
fishery management principals.
2. Ensure that flood control mechanisms and flood protection works are
designed so that they retain the quality and diversity of habitat in waterways
while providing for flood control.
3. Assist in any local government authorities plans for the development of
artifical wetlands and flood channels.
South Island Eel Industry Association: Eel Management Plan September 2009
aquatic ecosystems and organisms. However, gravel extraction has the opportunity to
create new eel habitats, through creation of ponds and backwaters, and retirement of
sediment settling ponds.
8.10 Barriers to Eel Migration
These include, dams, weirs, pump stations, control gates and culverts. While it is
recognised that flood control structures are needed during floods, if they are
operational continuously they could affect fish trying to pass through them.
Floodgates in many catchments can hinder the progress of elvers to the wider
catchment. They operate on a free-moving hinge mechanism. When the tide is
receding they are forced open by a downstream flow and when the tidal influence
pushes upstream they are forced closed to avoid salinity and flooding damage to the
catchment’s upper reaches.
It is thought that elvers migrate on incoming tides. At high tide during elver
migration there is a mass congregation of elvers at the floodgate but, with the opening
of the gate at the drop of the tide, most are swept back into the lower reaches of the
river. Other similar structures may block elver access because of excessive water
Culverts with free-fall have the potential for cutting off large areas of catchments
from recruitment, and eventually removing this area from the fishery. The culverts
usually occur under bridges and are often on private land. The same effects can be
caused by piped coastal outfalls. These may be a method of ensuring drainage over
mobile beaches, but are unacceptable because they prevent eel migration.
A far-reaching cause of habitat loss is dams, especially large hydro dams. Graynoth
& Booker (2008) estimated the total loss of longfin habitat trough hydro development
in NZ could support 6000 Tonnes of longfin eels. For example, at present the eel
SIEIA policy is that it shall:
1. Advocate for the removal of gravel and sand from dry water courses only.
2. Advocate for the designation of areas for the removal of sand and gravel,
to avoid the disturbance of significant eel areas. Liaise with local government
to prohibit extraction at known eel/elver migration times and from settling
sites for juveniles.
3. Encourage the creation of ponds and backwaters where gravel extraction
has taken place. These may be permanently connected to the main waterway
by a channel or rely on flooding or seepage for their renewal.
4. Encourage taking gravel from smaller areas using deeper holes, rather
than over large areas, to ensure less land disturbance and allow the
opportunity for wetland creation.
South Island Eel Industry Association: Eel Management Plan September 2009
populations upstream of the Aviemore dam and Roxburgh Dam are mostly remnants.
The continued presence of eels above these dams is mainly due to the great longevity
of longfin eels, or because eels have been artificially transported there. Most of the
eels are older then the dams. Furthermore, recruitment above other dams is severely
curtailed. For example, elver recruitment upstream of the Waitaki dam and Mararoa
Weir is considerably reduced by these structures.
This problem is compounded by the fact that few eels survive passage back
downstream through the turbines. This means that any spawning contribution from
eels living above the dams is lost. Fortunately, groups of commercial eel fishermen
have become involved with projects to transport elvers from below dams for release
upstream. Adult returning eels have also been trapped from above dams and released
Elver passes have been installed on some hydro dams. While these allow the passage
of some elvers, recruitment into upstream areas remains severely curtailed by the
dams, as the elver passes are not capable of attracting enough elvers to use them.
Allowing eel fishing in Conservation areas upstream of intractable migration barriers
will release fishing pressure from other waterways, and allow commercial fishermen
to fulfil their quota. In addition mature eels in these Conservation areas will be
This Plan has two paramount objectives associated with the problem of dams
and other structures blocking fish passage:
1. The provision of upstream and downstream fish passage is required
wherever possible, on all structures identified as blocking eel passage.
2. Where eel passage (upstream and/or downstream) is curtailed, and suitable
remedies to the problem cannot be implemented, the catchment upstream of
the dam should be declared an open “put and take” eel fishery, with direct
management input from SIEIA. The management of this fishery should
include the following provisions:
a) An active programme of artificial elver transfer into the upstream
catchment shall be put in place, overseen by SIEIA. The costs of this should
be borne by the consent holder.
b) The entire upper catchment shall be declared open to all fisheries
(customary, recreational and commercial). All usual rules and regulations
applying to these fisheries should apply, including existing QMS catch limits.
c) All eels caught larger than 4kg shall be released downstream of the fish
barrier. The cost of this should be borne by the consent holder.
d) All regulations preventing eel fishing in Conservation areas (e.g. National
Parks Act, Reserves Act) should be rescinded.
South Island Eel Industry Association: Eel Management Plan September 2009
caught for downstream release, which will improve their ability to migrate to sea to
Additional SIEIA recommendations are as follows:
1. Request that, as an affected party, it is consulted on all applications for resource
consent to dam or divert water, or for placement and/or operation of structures in
waterways which might be a barrier to eel migration. This shall include renewal of
existing consents.
2. Promote research into stocking rates and the sustainability of removing larger eels
(up to 220g) from downstream areas and moving them above barriers. The restocking
of areas must be done carefully because of high potential mortality, and the
long-term effects from over-stocking.
3. Suggest a conservative estimate of stocking density in the re-stocking of areas so
as to avoid any long-term effects on the host environment.
4. Advocate that dam owners implement research on the effects of dam maintenance
on eel habitat and survival, in particular sediment flushing and sediment deposition.
5. Consult with dam owners over the effects of lake level fluctuations on eels and
their habitat.
6. Advocate to the NZ Conservation Authority and Department of Conservation that
any ban on customary, recreational and/or commercial eeling is lifted in those
waterways where upstream recruitment and/or downstream migration is significantly
affected by damming or diversion.
For floodgates and pump stations, additional SIEIA recommendations are as
1. Advocate that Regional Councils continue to ensure that SIEIA is consulted as part
of the consents process for the erection and use of these structures.
2. Encourage Regional Councils to review the placement and effectiveness of
existing structures, and to look at their removal or modification where they are found
to be unnecessary or faulty.
3. Advocate that all new structures proposed are designed to allow for fish passage,
and to avoid capturing freshwater fish.
4. Request that tide gates are left open to allow fish passage when flood conditions
are unlikely.
5. Request a catch and transfer operation from those Councils which are operating
structures which are preventing elver passage.
For culverts, additional SIEIA recommendations are as follows:
South Island Eel Industry Association: Eel Management Plan September 2009
1. Recommend to Regional Councils that:
a) Culverts should have no free-fall so eel passage is not interrupted.
b) Flaps on culverts for flood control should only be deployed during flood events.
c) Care should be taken to ensure that water velocities through pipes are not too
strong so as to prevent elver passage. High water velocities restrict the ability of fish
to pass and the majority of elver movements occur at times of high flow. Where
necessary, baffles may be installed on culverts to reduce velocities.
2. Encourage local government authorities to consider the effects of culverts and
pipes when developing plans, and dealing with these issues with farmers.
9. Lake Ellesmere/Te Waihora
Lake Ellesmere/Te Waihora is one of the most important eel fisheries in New
Zealand. It supports significant commercial and customary fisheries. The
maintenance of this fishery is very important to commercial fishermen, as
considerable effort and resources have been committed to its development and
enhancement, and further resources are necessary for its ongoing maintenance.
The following issues relate specifically to the management and enhancement of the
commercial shortfin eel fishery of the lake.
9.1 Lake levels and Lake Opening
The lake mouth can be opened artificially by bulldozers, at virtually any time of year.
Sometimes the lake mouth will open naturally as a result of high inflows. Lake levels
fluctuate with inflows, and lake mouth openings (artificial or natural).
A spring-summer (October – mid December) lake opening event is essential to allow
glass eels in. Flounders also enter the lake in late spring or early summer, so opening
the lake at this time is most desirable for all fisheries. There is no need to limit the
number of openings during the spring/early summer period. Sometimes the best intake
of fish occurs in a second opening if it is close to the first.
If a spring-summer opening is not possible, it is preferred that the bulldozers (used for
lake openings) scrape back the shingle on the lake side to reduce the amount of beach
between the lake and the sea. This will allow glass eels to crawl through the shingle
from the sea to the lake.
A high lake during the mid-summer months (mid-December – mid April) is desirable,
as it allows eels access to the (more desirable) riparian feeding grounds. A low lake
during the mid-summer is detrimental to the fisheries, as it can lead to algal blooms
and high water temperatures. Both these events can lead to fish dying.
South Island Eel Industry Association: Eel Management Plan September 2009
It is preferred that there is no artificial lake opening during February or March. This
is the male shortfin migratory season. Migratory male shortfins are targeted by
fishers at this time of year, and their presence in the catch is essential to maintain a
sustainable shortfin fishery in Lake Ellesmere/Te Waihora. However, a lake mouth
opening late April or May is desirable, as it allows the migratory longfins and female
shortfins to escape to the sea to breed.
Therefore, the SIEIA’s preferred times for the lake to be open and for it not to be open
are as follows:
• One or two openings during spring/summer (October – mid December)
• No further openings during the summer months (mid December – mid April), with
lake levels preferably kept high
• One or more openings during late April/May
SIEIA is aware that there are other lake users who may require lake mouth openings
at different times, and it is recognised that it is necessary to seek a fair compromise.
SIEIA shall be involved in as many lake forums as possible, and lobby for the
above times for the lake to be open and for it not to be open.
9.2 Longfin Eels
The eel quota in Lake Ellesmere/Te Waihora can be fully caught with shortfins only.
Longfins are not common in the lake, and consequently there is no need to target them
in the catch. Accordingly, it has been the fisher’s policy that all longfin caught in
Lake Ellesmere/Te Waihora will be returned to the water.
In addition to the no-take policy for longfins, fishers should assist migratory long fin
eels of both sexes over the bar, at times when it is not likely that there is going to be
an April or May opening of the lake.
Longfin eels shall not be commercially taken from Lake Ellesmere/Te Waihora,
or feeder streams. All migratory longfins shall be released to the sea, if it
becomes unlikely that an April May lake opening will occur.
9.3 Migratory Eels
The association fully supports the taking of migratory male eels from the lake, to
assist in fulfilling ANG quota held. The reason why migratory male eels are taken is
because recruitment of shortfin eels is not adversely affected by this reduction in the
number of migratory male eels. They are not taken from any other waterway in NZ,
so there are always sufficient migratory males to sustain breeding rates of shortfin
South Island Eel Industry Association: Eel Management Plan September 2009
Migratory male eels are taken up to 300 grams in size. There are specific rules
covering the taking of these eels. These include:
1. Migratory males may only be taken from a within special area within Lake
Ellesmere (the male shortfin migratory area)
2. The season for taking migratory males is 1 Feb – 31 March.
It is common for nets to fill up with these eels as accidental by-catch outside the male
shortfin migratory area, and outside the 1 Feb – 31 March season. If these eels were
allowed to be taken to fulfil quota, this would be more efficient than the present
system where the taking of these eels is restricted by time and place. The association
does not see the need for the catching of these eels to be restricted, either by date or
by area. If fishers were able to land male migratory eels anywhere in the lake at any
time, this would allow for significantly more efficient catch rates. It would also mean
that fewer female eels would be taken from the lake to fulfil quota.
It is SIEIA policy for the male shortfin migratory eel season to be extended as far
as possible (preferably all year). There is no need for the imposition of a special
“male migratory area” within the lake, and this should be abolished.
The use of grading boxes on Te Waihora should continue.
9.4 Other Lake Ellesmere/Te Waihora issues
• Drying of Creeks
Periodically creeks running into the lake dry up leaving the eels to die. Members of
the association must at all times make themselves available to collect and release
these eels.
• Education
There has been considerable interest from a wide range of learning institutions
(schools, universities etc) about commercial fishing in this unique lake. SIEIA
Members are always available for education purposes, either about the lake and its
environs, or about the eel fishery.
• Health of the Lake
The health of the lake is of paramount importance to eel fishers. Members will lobby
for the enhancement of the health of the lake, feeder streams and associated riparian
areas. This will include participation in community meetings and submissions to
resource consent applications.
• Quota
South Island Eel Industry Association: Eel Management Plan September 2009
A precautionary approach has always been taken by the association in the matter of
quota setting. This will continue, but it is envisaged that with the continued
improvement in lake health, and the health of the eel fishery overall, a quota increase
may be appropriate in the near future.
• By Catch
All non-quota by-catch will be returned to the water. Birds will be prevented from
entering nets by not having front hoops poking out of the water.
• Ngai Tahu
Ngai Tahu are recognised as Tangata Whenua, and hold customary fishing rights in
the lake. Ngai Tahu has partial ownership of the lake bed, but this does not affect
commercial fishing rights and related activities. It is association policy to at all times
maintain effective working relationships with Ngai Tahu and papatipu runanga.
• Other Groups
It is SIEIA policy to foster and maintain contact with other groups interested in the
welfare of the lake.
The South Island has recently been invaded by a range of noxious aquatic fish and
plants. Some of these introductions (e.g. didymo) have been accidental, while others
(e.g. mosquito fish) have been deliberate. Once pest species become established in a
waterway, it is almost impossible to eradicate them. They can then be accidentally
transported throughout the catchment, and into new catchments, through the
movements of recreational and commercial fishermen.
The transfer of eel traps, boats and other equipment associated with commercial
eeling has been implicated in the spread of didymo and hornwort. It is also possible
for eelers to easily transfer Lagarosiphon and other aquatic weeds through equipment
transfer between catchments. For pest fish, they are most likely to be first discovered
(along with new aquatic weed outbreaks) by commercial eelers, who may capture
them in their eel traps, or discover them in the stomachs of captured eels.
Therefore, eel fishermen have an important role to play in the early detection and
prevention of spread of aquatic pests. It is important that they are aware of the threats
from these species. In particular, the following aquatic plant species pose a serious
threat to South Island waterways:
• Didymo (Didymosphenia geminata)
• Hornwort (Ceratophyllum demersum)
• Lagarosiphon (Lagarosiphon major, oxygen weed)
South Island Eel Industry Association: Eel Management Plan September 2009
• Egeria (Egeria densa, oxygen weed)
10.1 Didymo
Didymo has been present in New Zealand for at least 5 years. Didymo is known to
rapidly colonise new waterways, with all favourable habitats fully colonised within
about 12-18 months. Briefly, the adverse effects of excessive didymo growths in a
waterway can be categorised in the following manner
• Environmental – effects on other algae, native fish, trout, wading birds etc
• Health – direct effects causing itchy skin, rashes etc
• Water quality – effects on water odour, taste and texture
• Recreational – effects on fishing, jet boating, whitebaiting, swimming etc
• Aesthetic - the brown slimy look of didymo is not aesthetically pleasing
• Economic – clogging irrigation, water supply intakes, canals etc
SIEIA has developed a policy on minimising the spread of didymo (Appendix 5).
This shall be adhered to by all commercial eel fishermen, and SIEIA will advocate
that customary and recreational eel fishermen follow the same code of practice.
10.2 Other aquatic weeds
These mainly include Lagarosiphon (Lagarosiphon major, oxygen weed) and
Egeria (Egeria densa, oxygen weed). Hornwort (Ceratophyllum demersum) is
presently confined to the North Island, where it poses serious threats to flood
control systems, hydro-electric power generation and recreational boating
activities. Hornwort has previously been found in two locations in the South Island
– Centennial Pond in Timaru, and in a tributary of the Lower Moutere River in
Nelson. Both infestations were successfully eradicated using approved aquatic
herbicides. Another oxygen weed species – Hydrilla (Hydrilla verticillata) is
present in NZ but is presently confined to the Hawkes Bay Region.
All four species are known to be easily spread through the use of eel nets. The
procedures outlined in the policy on minimising the spread of didymo also apply to
waterways infested with these weeds. As it only takes a 1cm fragment of these
weeds to form a new colony, it is important that movement of equipment between
waterways is undertaken in a sanitary fashion.
SIEIA shall require all of its members to adhere to the policy on
minimising the spread of didymo (Appendix 5), at all times
South Island Eel Industry Association: Eel Management Plan September 2009
10.3 Pest Fish
There are a number of pest fish species infesting waterways throughout New
Zealand. Descriptions of these, along with their present distributions, are available
on the National Institute of Water and Atmosphere (NIWA) website
(www.niwa.co.nz). While it is not expected that commercial eeling activities
would exacerbate the spread of pest fish, it is important that any new or unusual
fish species is reported to SIEIA immediately. These reports can then be
forwarded to the relevant authorities.
The legislative framework for the management of eels is interwoven with legislation
for managing their habitats (fresh waters). Statutory mechanisms to achieve a
sustainable fishery are largely contained in the Fisheries Act. However, other statutes
such as the Conservation Act contain provision for the management of freshwater
fisheries. Therefore, there needs to be a significant degree of interagency liaison, and
consultation between Crown agencies and the harvesters (customary, recreational and
commercial). Therefore, the goal of a sustainable eel fishery needs to be reflected in
the roles and responsibilities of the central and local government agencies which
manage both the eel fishery and their habitat.
There have been a number of State and private-funded initiatives which have the
potential to reduce the viability and sustainability of the commercial eel fishery.
Examples includes the Draft West Coast Conservancy Management Strategy, which
preferred to exclude commercial fishing from all waterways managed by the
Department of Conservation (DoC). In addition, recent proposals for a mataitai
reserve for eels in coastal waters near Timaru would exclude commercial eeling from
these waters.
Of considerable concern is the re-designation of waterways for various purposes, such
as mataitai, National Parks, Conservation Reserves or Wildlife Refuges. These
designations all have specific policies of excluding the waterway from commercial
eeling. A reduced ability to fulfil quota through these various re-designation of
waterways will inevitably lead to a reduction in the sustainability of the commercial
eel fishery.
SIEIA shall require all of its members to report any new or unusual fish
species to the relevant Regional Council Biosecurity staff as soon as
South Island Eel Industry Association: Eel Management Plan September 2009
11.1 Maori Customary Interests and mataitai
Maori Treaty interests, as they relate to the eel fishery under the QMS, are provided
for in the Maori Fisheries Act 1989, the Treaty of Waitangi (Fisheries Claims
Settlement) Act 1992, and the Fisheries Act 1996.
Twenty percent of the commercial quota is allocated to iwi for treaty settlements. The
holder of this 20% quota is automatically a member of SIEIA. SIEIA will therefore
undertake all measures necessary to protect the value and substance of this, and other
quota held by its members. SIEIA’s role is to protect access of its members to the eel
fishery in the South Island.
Customary allowance is made for the taking of eels for customary purposes, for all
Quota Management Areas. While SIEIA is not directly responsible for protecting
access to this quota, there are significant opportunities for collaboration between
SIEIA and iwi in protecting the fishery and ensuring its sustainability.
Other legislation which provide for Maori treaty interests include the Resource
Management Act 1991, and the Conservation Act 1987. These Acts are principally
concerned with the conservation and enhancement of the eels’ freshwater habitats.
A number of areas previously utilised for commercial eeling have been closed through
the gazettal of mataitai (areas closed to commercial fishing and available for
customary fishing only). SIEIA will generally oppose applications for mataitai, as
this adversely affects commercial access to the eel fishery.
However, SIEIA supports the concept of mataitai, where they are confined to specific
traditional food gathering sites (e.g. Waikawa estuary and Mataura falls in Southland).
SIEIA will consider these applications on a case-by-case basis. Unfortunately, recent
applications for mataitai gazettal (e.g. Temuka District and Waihao catchment) have
included large areas of waterway. SIEIA will not support the gazettal of any mataitai
which requires the closure of wide tracts of waterway to commercial fishing. Reasons
for this policy include:
SIEIA will continue to work with customary fishing interests to ensure the
sustainability and enhancement of eel fisheries and their habitats, and
enhance opportunities for customary take wherever this is appropriate.
SIEIA policy is therefore to oppose all proposals for National Park and
Reserve re-designations, unless they are accompanied by either:
1. The ability to continue eeling on its existing basis, in accordance with this
Plan; or
2. The re-designation of existing protected waterways holding an equivalent
eel fishery, so that it becomes available for commercial eeling in accordance
with this Plan.
South Island Eel Industry Association: Eel Management Plan September 2009
1. Not all areas will hold mataitai values
2. Excluding large areas for commercial fishing reduces the catch efficiency and
sustainability of the commercial fishery
3. In many cases, gazettal application for mataitai are for the wrong reasons e.g.
protection of waterway values, or protection of larger eels. Excluding commercial
eeling does not necessarily achieve these purposes.
SIEIA will generally oppose applications for mataitai, as this adversely affects
commercial access to the eel fishery. However, where mataitai applications are
confined to traditional food-gathering areas, SIEIA will consider supporting
them on a case-by-case basis.
11.2 Ministry of Fisheries
The Ministry of Fisheries is responsible for the customary, recreational and
commercial harvesting of eels under the Fisheries Act 1996, and the Treaty of
Waitangi (Fisheries Claims Settlement) Act 1992. The Fisheries Act provides for the
implementation of the QMS for the harvesting of eels. The Ministry facilitates this
through the preparation and implementation of Fisheries Management Plans.
The Fisheries Act 1996 contains provisions to set or control harvesting levels for any
aquatic organism taken commercially or for traditional or recreational use. These
controls are classed as environmental standards. There are two types of harvest level
controls: those that control catch directly, i.e. catch levels set under a TAC, and those
that control catch indirectly, i.e. gear restrictions such as mesh sizes and area closures.
The Ministry operates a yield-setting process that establishes annual harvest levels.
The Fisheries Act allows this annual harvest to be allocated among user interests,
although the commercial fishers allocation is normally the only amount specified and
published by gazette notice.
Recreational harvest is governed by the Fisheries (Amateur Fishing) Regulations
1986. Specific regulations also cover exclusive eel fisheries such as Te Waiwera/
Lake Forsyth.
11.3 Department of Conservation (DoC)
The Minister of Conservation has the responsibility for the protection of indigenous
freshwater fisheries, including their unhindered access in waterways and their habitats
(Conservation Act S 6ab). DoC are also responsible for the protection of ecosystems,
particularly natural areas which may be representative of a particular region or area.
Many freshwater and riparian areas are managed by DoC. The nature of this
management varies in relation to the specific legislation governing these areas. These
are discussed below:
South Island Eel Industry Association: Eel Management Plan September 2009
National Parks and Reserves: Both the National Parks Act and the Reserves Act
contain clauses which require the complete protection of all indigenous species, which
means that commercial eeling is not permitted. Exceptions to this may occur where
an exclusion allowing commercial eeling is included in the National Park or Reserve
gazettal notice, or where commercial eeling is provided for in a National Park or
Reserve Management Plan.
Marginal Strips: Marginal strips are 20 metre “strips” of riparian land which have
been set aside under Section 24 of the Conservation Act, for public access. They are
not fixed areas of land, but move when the riverbed moves through natural erosion
and accretion. They are therefore, by definition, areas of dry land, and do not have
any direct influence on issues relating to the commercial eel fishery. A concession
from DoC is not required for commercial eel fishermen to move across marginal
strips in the course of eel fishing operations, as the primary purpose of the land is to
provide for public access. A concession is required from DoC if the marginal strip is
to be occupied (e.g. permanent campsites, boat ramps or boat storage sites), or where
the land is to be modified in any way (e.g. vegetation clearance for tracks, campsites
Stewardship Areas: Stewardship lands are managed by DoC for conservation
purposes in general. A concession is required from DoC to undertake commercial
eeling in waterways within these areas. Concessions are granted for commercial
eeling where this is consistent with the Conservancy Management Strategy (CMS) for
the region; or, in circumstances where a CMS is not operative for the region, where
this is consistent with Conservation General Policy and the Conservation Act.
In considering whether to grant concessions on Stewardship areas, DoC is confined to
considering the impacts of activities associated with eeling (for example, access and
camping). Matters of habitat and ecology have already have been addressed by the
Minister of Fisheries when setting the commercial eel quota. The effects of
commercial eeling on the sustainability of the fishery have also been addressed
through the QMS, and cannot be revisited by DoC when considering a concession
application. The effects on activities associated with eeling (such as access and
camping) can be addressed by DoC placing conditions on a concession, and can be
The exclusion of waterways from commercial eeling, through the gazettal of
new National Parks and/or reserves, is detrimental to the efficiency and
sustainability of the commercial eel fishing industry. Therefore, SIEIA will
oppose all proposals for gazetting new waterways into National Park or
Reserve, unless permanent exclusions, allowing for commercial eeling, are
placed in the instrument of gazettal.
SIEIA will ensure that all new and revised CMS’s provide for commercial
eeling on Conservation lands.
South Island Eel Industry Association: Eel Management Plan September 2009
determined by considering which particular activities are to occur in which particular
eeling locations.
DoC is charged with an advocacy role for conservation on lands and waterways of all
tenure. Coupled with its land management role, DoC has a strong role to play in
ensuring the sustainability of the eel fishery in the South Island.
Accordingly, the goal of this Plan (sustainability and enhancement of the resource), is
not incompatible with DoC’s role. However, this should not be mistaken for a
preservation role, which has recently appeared in some CMS drafts. It is considered
that the preservation of eels is appropriate only where lands have been set aside
specifically for this purpose (i.e. National Parks and Reserves), and where this goal is
not compromised by other factors. All other lands administered by DoC should
remain open to commercial eeling under the normal concessions process, to allow the
sustainability of the existing eel fishery to be maintained.
The commercial taking of eels from National Parks and Reserves is banned under the
National Parks Act and Reserves Act. This does not necessarily affect customary or
recreational eel fishing. These areas have been earmarked for the preservation of
ecosystems in their natural state. Despite this, some areas of National Park are unable
to sustain eels in their natural state, because of downstream hydro development. For
example, the Mararoa Weir and Monowai Power Station prevent natural elver
recruitment into the Lake Monowai, Manapouri and Te Anau catchments. These
catchments should be opened up to commercial fishing, as they are unable to sustain a
population of eels in their natural state. This would allow the TAC to be taken, while
relieving fishing pressure on other waterways, thereby enhancing the sustainability of
the fishery.
This policy will help facilitate the sustainable fishery, improve the impetus for eel
enhancement, and improve the escapement of adult migrating eels (all migrating adult
eels will be released unharmed below the dam)
11.4 Regional and District Councils
Regional and District Councils are responsible for Resource Management Act (RMA)
administration. The relevance to the eel fishery is through the RMA requirement to
protect the life supporting capacity of water and ecosystems, and of significant
habitats of indigenous fauna. Regional and District Councils must provide for the
When applying for a commercial eeling concession on DoC – managed lands,
SIEIA members shall pinpoint the areas to be fished, and the activities which
will occur on those areas (e.g. camping, boat mooring storage of eels etc).
SIEIA Policy is to promote the opening of commercial fishing in National
Parks and Reserves containing areas which have been impacted with fishpassage
problems by hydro dams, or other structures.
South Island Eel Industry Association: Eel Management Plan September 2009
sustainable management of natural and physical resources, including protection from
inappropriate use and development.
Regional Councils have primary policy and planning functions under the RMA, that
regulate land use, water quality and quantity, and a range of other environmental
issues impacting on fresh water eel habitats. Regional Councils must promote the
sustainable management of natural and physical resources through their policy and
planning function.
Those sections of the RMA which are of relevance to eel habitat include:
S 5: requires Councils to promote the sustainable management of natural and
physical resources.
S 6 (i) the preservation of the natural character of the coastal environment (including
the coastal marine area), wetlands, and lakes and rivers and their margins, and the
protection of them from inappropriate use and development
S 6 (ii) The protection of areas of significant indigenous vegetation and significant
habitats of indigenous fauna.
S 6 (iii) The relationship of Maori and their culture and traditions with their ancestral
lands, water, sites, waahi tapu and other taonga.
S 7 Kaitiakitangata. This is a principal of “guardianship”.
S 8 The principals of the Treaty of Waitangi.
The Regional Planning process has been ongoing since the inception of Regional
Councils in 1989. Most Regional Water and Land Plans have now been drafted, with
many now operative. The planning process is, however, ongoing, with Plan updates
and changes being required from time to time. It is important that SIEIA is involved
in all of these processes at the early planning stage.
Regional Councils are also responsible for environmental monitoring and RMA
compliance. SIEIA shall access this information where necessary, for its own
planning purposes.
Sustainable land use and the protection of aquatic ecosystems from the effects of land
based activities are District and City Council functions. The District and City
planning and policy mechanisms are similar to those employed by Regional Councils.
SIEIA shall liaise with these organisations in the same way as for Regional Councils.
Regional Councils are also responsible for managing structures in waterways. A
significant problem with structures is their blocking eel passage, upstream and/or
downstream. DoC administers the Fish Pass Regulations to ensure effective access to
and from the sea for eels. Therefore, SIEIA will liaise with DoC and the relevant
Regional Council to ensure that consent applications for in-river structures do not
block upstream or downstream eel passage.
South Island Eel Industry Association: Eel Management Plan September 2009
11.5 Other Government Departments
Management of the eel fishery includes the issue of the provision of access for
customary, recreational and commercial fishermen. The wide variety of Crown
agencies managing access to waterways in New Zealand makes integrated access
management difficult. There is little or no consistency between Crown agencies in
how their “portion” of riverbed or lakebed is managed, and no clear legislation or
regulations on how access, especially for commercial activities, should be managed.
Management of most riverbeds and lake beds in New Zealand is undertaken by Land
Information NZ (LINZ), as these lands are considered Unalienated Crown lands
(UCL) under the Land Act 1949. However, some riverbeds such as the Shag River in
North Otago are privately owned for part of their length. Most rivers and lakes also
have portions of their bed and/or riparian margins owned by other Crown agencies.
For example:
• Marginal strips (Conservation Act 1987) are managed by DoC.
• Riverbed reserves and Lake Reserves (Reserves Act 1977) are managed by DoC, unless
they are Local Purpose Reserves which are managed by the District Council.
• Road reserves adjacent waterways are managed by District Councils or Unitary Authorities,
unless the road is formed, whereby it is managed by Transit NZ.
• Crown riverbeds and lakebeds, including “non-core hydro development” land around hydro
lakes taken for power generation, are managed by LINZ
• Esplanade Reserves are managed by either DoC or the local District Council.
• Riverbed land in the Canterbury Region with ad medium filum rights is owned
by the Crown and managed by LINZ; but is often considered the de facto
private property of the adjacent landowner.
This fractured management structure for NZ waterways requires ongoing consultation
with all relevant authorities.
11.6 Fish & Game Councils
The New Zealand Fish & Game Council manages sports fish and game via the
Conservation Law Reform Act 1989. The principal species managed are trout and
salmon, and waterfowl (ducks, Canada Geese etc), which all rely on healthy aquatic
environments to remain sustainable. The Fish & Game Council does not manage the
waterways themselves, nor do they manage any aspect of the eel fishery.
There are many common issues relevant to Fish & Game Councils and SIEIA,
especially those outlined in Section 8 of this Plan. SIEIA shall maintain close links
SIEIA shall maintain dialogue with all authorities governing riverbed
activities to ensure a consistent approach to issues relating to the South Island
eel fishery.
South Island Eel Industry Association: Eel Management Plan September 2009
with National and Regional Fish & Game Councils, and where possible will
collaborate on issues of mutual interest.
12.1 Illegal activities
Section 7.2 outlines SIEIA policy on reporting illegal activities in waterways, while
Section 9 details systems for reporting biosecurity issues. In addition to these issues,
commercial eel fishermen have had significant problems with tampering with fyke
nets and associated equipment. These are normally “set” overnight, often in remote
areas where there is limited security.
SIEIA promotes a zero-tolerance policy against illegal tampering with fishing
equipment. It is an offense to wilfully interfere with any commercial eeling
equipment, without first notifying the fisherman concerned. There are exceptions
which may occur where fishing equipment is in danger from being lost through
flooding etc. However, it is expected that any landowner or other member of the
public who has concerns about commercial eeling activities should contact that
fisherman or SIEIA immediately.
12.2 Bycatch
Occasionally, trout, salmon, coarse fish and/or native fish may enter commercial eel
nets. In all cases, these fish are immediately released back into the waterway
unharmed. Pest fish should be retained and frozen for further identification, and their
location recorded
Some native fish species are considered rare and/or endangered. These include the
Canterbury mudfish, giant kokopu and lamprey. Records of the location caught, date
and numbers of these species should be recorded by the fisherman, and forwarded to
the SIEIA.
12.3 Consultation
Previously, consultation on issues relating to eel fisheries was conducted through the
Regional Eel Management Committees. These Regional Eel Management
Committees have now been wound-up, with advocacy functions transferring to SIEIA
and Customary interests. While SIEIA cannot advocate on behalf of customary
interests, it is expected that mutual agreement will occur on most issues.
It is SIEIA policy to seek immediate prosecution of any person who interferes
with SIEIA members’ equipment.
South Island Eel Industry Association: Eel Management Plan September 2009
Consultation with government departments and territorial authorities will continue
through SIEIA involvement with various planning processes. Where issues arise
where agreement has not been reached, SIEIA shall seek further consultation with
decision-makers prior to litigation (an exception is tampering with fishing equipment,
where SIEIA Policy is to prosecute forthwith).
Consultation with other organisations and the general public will continue on a case
by case basis, including through the 24-hour freephone. SIEIA encourages the public
to become involved in the sustainability of freshwater ecosystems and the fisheries
contained therein, and welcomes enquiries from schools etc for educational and
promotional purposes.
MSC Principle 3 states:
The fishery is subject to an effective management system that respects local, national
and international laws and standards and incorporates institutional and operational
frameworks that require use of the resource to be responsible and sustainable.
The intent of this principle is to ensure that there is an institutional and operational
framework for implementing Principles 1 and 2, appropriate to the size and scale of
the fishery. This Principle has two main criteria – management systems and
operational. This Plan has been developed to specifically meet these criteria.
Specific sections of this Plan which correspond to each management or operational
criteria are set out below in index form.
13.1 Management System Criteria:
1. The fishery shall not be conducted under a controversial unilateral exemption to an
international agreement. No such exemption exists for NZ eel fisheries.
The management system shall:
2. Demonstrate clear long-term objectives consistent with MSC Principles and
Criteria and contain a consultative process that is transparent and involves all
interested and affected parties so as to consider all relevant information, including
local knowledge. The impact of fishery management decisions on all those who
depend on the fishery for their livelihoods, including, but not confined to subsistence,
artisanal, and fishing-dependent communities shall be addressed as part of this
process. See Section 11.3.
SIEIA shall endeavour to hold regular meetings on South Island eel
management issues.
South Island Eel Industry Association: Eel Management Plan September 2009
3. Be appropriate to the cultural context, scale and intensity of the fishery – reflecting
specific objectives, incorporating operational criteria, containing procedures for
implementation and a process for monitoring and evaluating performance and acting
on findings. See Section 4.
4. Observe the legal and customary rights and long term interests of people dependent
on fishing for food and livelihood, in a manner consistent with ecological
sustainability. This is the purpose of the Fisheries Act.
5. Incorporates an appropriate mechanism for the resolution of disputes arising within
the system. See Section 11.3.
6. Provide economic and social incentives that contribute to sustainable fishing and
shall not operate with subsidies that contribute to unsustainable fishing. Section 6
outlines enhancement opportunities. No subsidies apply to commercial eeling in
7. Act in a timely and adaptive fashion on the basis of the best available information
using a precautionary approach particularly when dealing with scientific uncertainty.
See Section 4.3.
8. Incorporate a research plan – appropriate to the scale and intensity of the fishery –
that addresses the information needs of management and provides for the
dissemination of research results to all interested parties in a timely fashion. See
Section 13.
9. Require that assessments of the biological status of the resource and impacts of the
fishery have been and are periodically conducted. See Section 4.3.
10. Specify measures and strategies that demonstrably control the degree of
exploitation of the resource, including, but not limited to:
a. setting catch levels that will maintain the target population and ecological
community’s high productivity relative to its potential productivity, and account for
the non-target species (or size, age, sex) captured and landed in association with, or as
a consequence of, fishing for target species;
b. identifying appropriate fishing methods that minimise adverse impacts on habitat,
especially in critical or sensitive zones such as spawning and nursery areas;
c. providing for the recovery and rebuilding of depleted fish populations to specified
levels within specified time frames;
d. mechanisms in place to limit or close fisheries when designated catch limits are
e. establishing no-take zones where appropriate;
Measures are contained throughout this Plan which meet these criteria.
11. Contains appropriate procedures for effective compliance, monitoring, control,
surveillance and enforcement which ensure that established limits to exploitation are
not exceeded and specifies corrective actions to be taken in the event that they are.
Measures are contained throughout this Plan which meet these criteria.
South Island Eel Industry Association: Eel Management Plan September 2009
13.2 Operational Criteria
Fishing operations shall:
12. Make use of fishing gear and practices designed to avoid the capture of non-target
species (and non-target size, age, and/or sex of the target species); minimise mortality
of this catch where it cannot be avoided, and reduce discards of what cannot be
released alive. See Sections 7.3 and 11.2.
13. Implement appropriate fishing methods designed to minimise adverse impacts on
habitat, especially in critical or sensitive zones such as spawning and nursery areas.
Commercial eel fishing methods do not cause these effects.
14. Not use destructive fishing practices such as fishing with poisons or explosives.
Such practices are illegal in New Zealand.
15. Minimise operational waste such as lost fishing gear, oil spills, on-board spoilage
of catch, etc.; Commercial eel fishing is not subject to these effects.
16. Be conducted in compliance with the fishery management system and all legal and
administrative requirements. This is SIEIA policy.
17. Assist and co-operate with management authorities in the collection of catch,
discard, and other information of importance to effective management of the
resources and the fishery. This is SIEIA policy.
A great deal of research has been conducted on a wide range of issues relating to eels
and eel fisheries in New Zealand. It is not SIEIA’s intention to repeat or enlarge on
this research. However, there are a number of research projects relating to the
sustainability and enhancement of the fishery which may require further work. These
are listed below in priority order, along with the preferred primary funding agency:
1. Continuation of CPUE and recruitment monitoring. This is funded primarily from
SIEIA members through levies with contributions from MFish. This research is
carried out through a time-series of data to monitor the relative recruitment of shortfin
and longfin eels by co-ordinating to specific standards the collection of data on
abundance, timing of migration and species composition of elver runs at four
locations: Karapiro, Matahina, Waitaki and Arnold; for the elver migrations
2008/2009, 2009/2010, 2010/2011 and 2011/2012.
2. A study on the long-term survival rates of eels transferred upstream of hydro dams.
This study should look at survival rates of transferred eels in various habitats and
situations, growth rates, and intra-catchment migration. As the problem of blocked
elver passage is caused by dams, this study should be funded by the dam consent
South Island Eel Industry Association: Eel Management Plan September 2009
3. To investigate the correlation between elver movement and environmental factors
such as water temperature and flow. This will allow for improved capture of
migrating elvers below dams for transfer purposes. As the problem of blocked elver
passage is caused by dams, if this study is deemed necessary then it should be funded
by the dam consent holder.
4. Movement and survival of female longfins transferred downstream below dams.
This will gauge the effectiveness of transferring >4kg female longfins to suitable
habitats below hydro dams, and their subsequent ability to move out to sea to breed.
As the problem of blocked adult downstream passage is caused by dams, this study
should be funded by the dam consent holder.
Beentjes, M.P.; Dunn, A. 2008. CPUE analyses of the South Island commercial
freshwater eel fishery, 1990–91 to 2005–06.
New Zealand Fisheries Assessment Report 2008.
Graynoth, E.; Booker D. 2008. Biomass of longfin eels in medium to large rivers.
New Zealand Fisheries Assessment Report 2008.
Graynoth, E.; Jellyman, D.J.; Bonnett, M. 2008.
Spawning escapement of female longfin eels.
New Zealand Fisheries Assessment Report 2008/7. 57 p.
Jellyman, D.J. 2008. Status of New Zealand fresh-water eel stocks and
management initiatives.
ICES Journal of Marine Science Advance Access published June 21, 2007.
2007 International Council for the Exploration of the Sea. Published by Oxford
Martin, M.L.; Boubée, J.; Bowman, E. 2008. Recruitment of Freshwater Eels 2006–
07 and 2007–08.
Research Progress Report for Ministry of Fisheries Research Project EEL2006/01
Objective 1.
Young, R.G.; Keeley, N.B.; Shearer, K.A.; Crowe, A.L.M. 2004.
Impacts of diquat herbicide and mechanical excavation on spring-fed drains in
Marlborough, New Zealand.
Science For Conservation 240.
South Island Eel Industry Association: Eel Management Plan September 2009
APPENDIX 1: Commercial eel catch data
Catch data prior to 1983 were only available by calendar year. Licensed Fish
Receiver Returns (LFFRs), Quota Management Reports (QMRs) and Monthly
Harvest Returns (MHRs), provide the most accurate data on landings over the period
1988-89 to 2004-2005 for the whole of New Zealand (Table 1).
Table 1: NZ Eel catch data (tonnes) from 1988-89 to 2007-08 based on –
LFRRs, QMRs and MHRs).
Year Landings
1988-89 1 315.3
1989-90 1 356.4
1990-91 1 590.2
1991-92 1 585.2
1992-93 1 465.9
1993-94 1 255.0
1994-95 1 438.3
1995-96 1 429.0
1996-97 1 342.1
1997-98 1 209.9
1998-99 1 218.9
1999-00 1 133.5
2000-01 1 070.9
2001-02 962.3
2002-03 802.5
2003-04 736.8
2004-05 711.7
2005-06 771
2006-07 730
2007-08 660
Catches remained relatively stable over the period until 2000-2001 when landings
dropped from 1070 t. Landings reduced further from 2001-02 to 200-05, as eel stocks
were progressively introduced into the QMS. For the period 1991-92 to 2004-05, the
North Island provided on average 65% of the total New Zealand eel catch (Table 2).
Table 2: North and South Island eel catch (t) compiled from data from
individual processors 1991-92 to 1999-00 and LFRR/QMR 2000–01 to 2007-08
Island* Total
HR Total NZ
1991-92 989.2 631.7 1 620.9 1 585.2
1992-93 865.3 597.1 1 462.3 1 465.9
South Island Eel Industry Association: Eel Management Plan September 2009
1993-94 744.1 589.8 1 333.8 1 255.0
1994-95 1 004.4 510.8 1 515.2 1 438.3
1995-96 962.4 459.6 1 480.9 1 429.0
1996-97 830.3 418.4 1 248.7 1 342.1
1997-98 794.6 358.6 1 153.1 1 209.9
1998-99 804.2 381.2 1 185.4 1 218.9
1999-00 723.2 396.0 1 119.2 1 133.5
2000-01 767.5 303.4 1 070.9
2001-02 643.6 318.8 962.3
2002-03 506.7 295.8 802.5
2003-04 454.4 282.4 736.8
2004-05 426.3 285.4 711.7
2005-06 497 285 781
2006-07 440 285 725
2007-08 372 288 660
Catch effort landing returns (CELR) provide landings by Fisheries Management Area.
Prior to the 2000-2001 fishing year, three species codes were used to record species
landed, SFE (shortfin), LFE (longfin) and EEU (eels unidentified). A high proportion
of eels (46% in 1990/91) were identified as EEU between the fishing years 1989-90
and 1998-99. Prorating the EEU catch by the ratio of LFE:SFE by fishing year
provides a history of landings by species (Table 3), although it should be noted that
prorated catches prior to 1999/00 are influenced by the high proportion of EEU and
may therefore not provide an accurate species breakdown. The introduction of new
Eel Catch Returns (ECELR) in 2000/01 improved the species composition
information with the deletion of the EEU code. The species proportion has remained
relatively constant from the 1995/96 fishing year until the introduction of the North
Island fishery into the QMS in 2004. (South Island catch limits are set for SFE and
LFE combined). Shortfins are the dominant species in the fishery, on average
constituting 66% of catches between 1995/96 and 2004-05.
Table 3: Total NZ eel landings by species (CELR landed)
Total CELR
1989-90 452.5 616.7 1 069.2
1990-91 615.6 808.4 1 424.0
1991-92 611.9 941.2 1 553.1
1992-93 740.7 872.4 1 613.1
1993-94 587.8 691.5 1 279.3
1994-95 587.9 909.2 1 497.1
1995-96 517.7 977.1 1 494.8
1996-97 465.2 841.4 1 306.6
1997-98 441.7 881.2 1 322.9
1998-99 433.9 824.4 1 258.3
1999-00 413.0 741.2 1 154.2
2000-01 387.7 698.0 1 085.7
2001-02 360.0 660.0 1 020.0
2002-03 278.7 560.3 839.0
South Island Eel Industry Association: Eel Management Plan September 2009
2003-04 215.6 509.9 725.6
2004-05 253.7 459.6 713.3
2005-06 226 553 774
2006-07 209 524 733
2007-08 195 456 651
The species proportion of the landings varies by geographical area. From analysis of
landings made into eel processing factories and estimated landings from CELRs,
longfins were the predominant species in most areas of the South Island. Now,
shortfins make up the entire catch from Lake Ellesmere/Te Waihora, and a larger
proportion of the catch from Lake Brunner, and the Waipori Lakes. Prior to the QMS,
in the North Island there has been a general decline in longfin landings relative to
shortfin landings over a 13 year period from 1990-91 to 2002-03. Estimated longfin
catches declined from about 340 tonnes to 140 tonnes over this period, while shortfin
landings fluctuated between 360 tonnes and 600 tonnes, but showed no decline in
landings. The eel fishery catches are predominantly pre-migratory eels, with the
exception of Lake Ellesmere/Te Waihora, where significant quantities of seaward
migrating adult eels are taken during the period February to March.
South Island Eel Industry Association: Eel Management Plan September 2009
APPENDIX 2: New Zealand Eel Biology
World-wide there are over 15 species of freshwater eel, with the majority of species
occurring in the Indo-Pacific region. New Zealand freshwater eels are regarded as
temperate species, similar to the Northern Hemisphere temperate species, the
European eel A. anguilla, the North American eel A. rostrata, and the Japanese eel A.
japonica. The short-finned eel (A. australis) is found in both Australia and New
Zealand. However, the Australian long-finned eel (A. reiholdii) is a different species
to the New Zealand long-finned eel (A. dieffenbachii). The Australian long-finned eel
is occasionally caught in New Zealand waters, principally in the North Island.
3.1 Life Cycle and Reproduction
All species of anguillid eels are catadromous, spending the majority of their life cycle
in fresh water or estuaries and reproducing once only in the ocean before dying. The
major part of the life-cycle is spent in freshwater or estuarine/coastal habitat.
Freshwater eels have a life history unique among fishes that inhabit New Zealand
waters. Spawning of both species is thought to occur in the South Pacific Ocean, but
no precise spawning location for either species has been identified. Eggs are thought
to be pelagic and hatch after about two days. Progeny undertake a long oceanic
migration to freshwater where they grow to maturity before migrating to the oceanic
spawning grounds. Eels are presumed to spawn once and die after spawning.
The longfin eel is endemic to New Zealand and is thought to spawn east of Tonga.
The shortfin eel is also found in South Australia, Tasmania, and New Caledonia.
Spawning is thought to occur northeast of Samoa
The newly hatched larvae, or leptocephali, survive on the resources of their yolk sac
for about five days before commencing exogenous feeding. As the leptocephali feed
and grow, they are transported toward the eastern Australian coastline by the South
Equatorial Current, and then along the coast by the East Australian Current.
Larvae (leptocephali) are transported to New Zealand via the South Equatorial
Current, and the metamorphosed juveniles (glass eels) enter freshwater from August
to November. In the lower reaches of rivers, glass eels metamorphose into darkly
pigmented elvers which migrate upstream.
The migrations upstream are remarkable, not only for the numbers of elvers involved
in some years, also for the tenacity with which they approach obstacles. Elvers will
climb up the wetted sides of waterfalls and walls on their migration inland. This
migration may take several years before the elvers settle into suitable habitats and
take up a territorial existence.
The subsequent upstream migration of elvers (pigmented juvenile eels) distributes
eels throughout the freshwater habitat. The two species occur in abundance
throughout New Zealand and have overlapping habitat preferences with shortfins
South Island Eel Industry Association: Eel Management Plan September 2009
predominating in lowland lakes and muddy rivers, while longfins prefer stony rivers
and penetrate further inland to high country lakes.
Adult eels migrate back to the sea to breed when they have attained a suitable size and
perhaps fat level. It may take from 50 to 80 years or more before longfin eels in cool
waters of the inland South Island attain sufficient size and body fat reserves to migrate
to their spawning grounds in the South Pacific ocean. Metamorphosis from resident
adult eel to migrating adult eel involved degeneration of the gut, gonad development,
eye enlargement and colour change. When the river floods in autumn, groups of
migrating eels drift downstream and swim out to sea. Where they go to breed is
unknown, but it is thought to be the tropical South Pacific Ocean, perhaps somewhere
off Tonga. Migrant eels never return and presumably die after spawning.
3.2 Growth rates
Age and growth of New Zealand freshwater eels was reviewed by Horn (1996).
Growth in freshwater is highly variable and dependent on food availability, water
temperature and eel density. Eels, particularly longfinned eels, are generally long
lived. Maximum recorded age is 60 years for shortfins and 106 years for longfins.
Ageing has been validated. Growth rates determined from the commercial catch
sampling programme (1995–97) indicate that in both the North and South Islands,
growth rates are highly variable within and between catchments. Shortfins often grow
considerably faster than longfins from the same location, although in the North Island
longfins grow faster than shortfins in some areas (e.g. parts of the Waikato
catchment). South Island shortfins take, on average, 12.8 years (range 8.1–24.4 years)
to reach 220 grams (minimum legal size), compared with 17.5 years (range 12.2–28.7
years) for longfins, while in the North Island the equivalent times are 5.8 years (3–
14.1 years) and 8.7 years (range 4.6–14.9 years) respectively.
Growth rates are usually linear. Sexing immature eels is difficult, but from length at
age data for migratory eels, there appears to be little difference in growth rate between
the sexes. Age at migration may vary considerably between areas depending on
growth rate. Males of both species mature at a smaller size than females. Migration
appears to be dependent on attaining a certain length/weight combination and
condition. The range in recorded age and length at migration for shortfin males is 5–
22 years and 40–48 cm, and for females 9–41 years and 64–80 cm. For longfinned
eels the range in recorded age and length at migration is 11–34 years and 24–67 cm
for males, and 27– 61 years and 90–158 cm for females. However because of
variable growth rates, eels of both sexes and species may migrate at younger ages.
3.3 Recruitment biology
There are few data on the recruitment biology of glass eels and elvers into New
Zealand freshwaters. Glass eels enter rivers and streams around New Zealand between
August and December. Regional differences in mean size and condition show an
arrival pattern from the north in an anti-clockwise dispersal pattern around New
Zealand. There is evidence of annual variation influenced by the El Nino Southern
Oscillation (ENSO), with the arrival route of glass eels from the northwest being
South Island Eel Industry Association: Eel Management Plan September 2009
stronger during the El Nina phase and stronger from the northeast during the El Nino
phase. The most likely primary vector for larval transport from the northwest is the
East Australian current. A more direct arrival route from the northeast, via the trade
wind drift, may be more important during the El Nina phase. The recent discovery of
the Antarctic Circumpolar Wave that effects how the ENSO cycles develop could also
provide a further mechanism for the periodic alteration of glass eel recruitment.
Rather that a fixed spawning ground, it has been suggested that the tropical spawning
grounds may not be geographically fixed but associated with thermal fronts that might
There are no glass eel data or long term data sets on elver migrations in New Zealand,
such as are available in the Northern Hemisphere for A. anguilla and A. rostrata,
which provide some information on recruitment. Northern Hemisphere stocks have
shown substantial declines in recruitment over recent decades. Available information
on recent recruitment trends of New Zealand eels is equivocal. Research on
recruitment has investigated available information on glass eel recruitment, elver
migrations, age class structure of juvenile eels and length frequency data from
commercial catch sampling. From the age composition of juvenile eels there is
evidence that glass eel recruitment has declined in two North Island and three South
Island waters. Glass eel runs are estimated to be a quarter of the size of runs prior to
the early 1970’s. There is anecdotal evidence that glass eel runs are now substantially
smaller in the Waikato River that in the 1970’s. However specific studies on the
variability and temporal abundance of glass eels over a five-year period from 1995 to
2002 showed no decline in recruitment for either species. The density of shortfin eels
exceeded that of longfins for any one year but the annual trends for both species were
generally similar.
3.4 Distribution and Key habitats (feeding, spawning, migration etc)
Shortfin and longfin eels are widely distributed in South Island freshwaters.
Generally, shortfin eels live in lowland waterways, while longfins will live in streams
from sea level to the subalpine zone. Eels live in a variety of habitat types, ranging
from the open ocean to estuaries, rivers, lakes, swamps, creeks and farm dams,
sometimes appearing in places which have no recognisable connective waterways.
Eels are opportunistic feeders, utilising multiple levels of the food chain, including
phytoplankton, insects and crustaceans, fish and other prey. Smaller eels feed
predominantly on aquatic insects, crustaceans and zooplankton. Larger eels become
progressively more piscivorous as they grow bigger, and are more likely to scavenge.
Sex determination in eels is dependant on several factors, including salinity,
temperature, diet, population density and other environmental factors. Generally
speaking, the proportion of females in eel populations increases as population density
3.5 Spawning biology
The life-cycle of each species has not been completely resolved but all evidence
supports the proposition of a single (panmictic) spawning stock for each species.
South Island Eel Industry Association: Eel Management Plan September 2009
Longfins are endemic to New Zealand and are assumed to be a single stock.
Biochemical evidence suggests that New Zealand and Australian shortfins are a single
biological stock. Within a catchment, adult eels undergo limited movement until their
seaward spawning migration. Therefore once glass eels have entered a catchment,
each catchment effectively contains a separate population of eels. For management
purposes, the South Island fishery has been divided into six fishstocks (species
combined). The Chatham Island fishery comprises two fishstocks and the North
Island eight fishstocks (species separate).
South Island Eel Industry Association: Eel Management Plan September 2009
APPENDIX 3: Eel Fisheries
Historically, eels were a very important food source for Maori. Maori developed
sophisticated and effective methods of harvesting and a good understanding of the
habits and life history of eels. Fishing methods included eel weirs, which
demonstrated a high degree of engineering skill developed prior to European
colonization. Hinaki (eel pots) and other methods of capture were also used. The
customary fishery declined after the 1900s but in many areas Maori retain strong
traditional ties to eels and their harvest.
In the South Island, Lake Forsyth (Waiwera) and its tributaries have been set aside
exclusively for eel management and harvest by Ngai Tahu. Other areas; the lower
Taumutu (Te Waihora), Wainono Lagoon, and lower Pelorus River; have been set
aside as non-commercial areas. In the North Island, commercial fishing has been
prohibited in the Taharoa Lakes, Whakahi Lagoon, Lake Poukawa and the Pencarrow
lakes (Kohangapiripiri and Kohangatera) and catchments in recognition of the special
value of these areas for customary purposes.
Customary fishers desire eels of a greater size, over 750 mm and 1kg. For the
introduction of the South Island eel fishery into the QMS, an allowance was made for
customary harvest set at 20% of the TAC for each QMA, equating to 107. 3 t. For
introduction of the North Island fishery into the QMS, the customary take was
estimated to be 73 tonnes for shortfins and 46 tonnes for longfins.
Eels may be harvested for customary purposes under the authority of permits issued
under fisheries regulations. Kaitiaki are in place for some areas and estimates of
customary harvest can be expected in future.
The recreational fishery for eels includes any eels taken by recreational fishers under
the amateur fishing regulations and includes any harvest by Maori not taken under the
authority of a permit issued under fisheries legislation. There is no quantitative
information on the recreational harvest of freshwater eels. The extent of the
recreational fishery is not known although the harvest by Maori might be significant.
The recreational catch is taken mainly for human consumption, but occasionally for
pet food. In October 1994, a recreational individual daily bag limit of 6 eels was
introduced throughout New Zealand. A further restriction on recreational eel fishing
is a minimum length of taken fish being 12 cm.
Eels are often caught as a by-catch of trout and coarse-fish anglers. Coarse fish
anglers make a point of releasing eels unharmed. However, many trout fishermen
retain the idea that eels are harmful to trout fisheries (this is untrue), and will kill the
eels and leave them to rot on the streambank.
South Island Eel Industry Association: Eel Management Plan September 2009
The Ministry of Fisheries is developing a “Shared Fisheries Project”. This is focused
on improving the management of New Zealand’s “shared fisheries” – i.e. the
fisheries where customary, amateur and commercial uses intersect. The project’s aim
is to increase the value obtained from the use of shared fisheries. Value encompasses
both market and non-market values associated with commercial, amateur and
customary fishing. The project is wide in scope and addresses some complex issues.
Two key objectives are to increase certainty in the allocation framework and to better
recognise non-commercial values.
The Minister has also announced that he intends to establish an independent Amateur
Fishing Trust with a dual purpose, which is to:
1. Work with existing amateur fishing organisations to develop a model for a
long-term, accountable representation structure for the sector, and
2. In the interim, provide professional services to existing sctor organisations and
representatives to support their capacity to engage in ongoing management
The Trust would be constitutionally constrained from acting as a representative or
lobby group in its own right. It will be important that consultation on the nature and
extent of the recreational eel fishery occurs with the Amateur Fisheries Trust.
The history of the commercial eel fishery is well documented. The contemporary
commercial fishery dates from the mid-1960s when markets were established in
Europe and Asia. The freshwater eel fishery is distributed throughout the freshwaters
(lakes, rivers, streams, farm ponds, tarns) and some estuarine and coastal waters of
New Zealand, including the Chatham Islands. Virtually all eels (98%) are caught with
baited fyke nets or hïnaki traps.
South Island Eel Industry Association: Eel Management Plan September 2009
APPENDIX 4: Eel Quota Management Areas
South Island Eel Industry Association: Eel Management Plan September 2009
APPENDIX 5: Policy on minimising the spread of didymo
SIEIA is aware of the effects of Didymo on the
Environment and is proactive in eliminating the
risk of the spread of Didymo to other waterways.
In doing so the following guidelines are to be
adhered to:
To ensure you do not spread Didymo, if you are moving between waterways
before and after entering, you must clean items using the following methods:
1. Check: Before leaving the river, remove all obvious clumps of
algae and look for hidden clumps. Leave them at the affected
site. If you find any later, do not wash them down drains. Treat
them with the approved cleaning methods below, dry them and
put them in a rubbish bin.
2. Clean: Soak and scrub all items for at least one minute in
either hot (60ºC) water, a two percent solution of household
bleach or a five percent solution of salt, nappy cleaner,
antiseptic hand cleaner or dishwashing detergent. A two
percent solution is 200 ml, a five percent solution is 500 ml (two
large cups), with water added to make 10 litres.
3. Dry: If cleaning is not practical, after the item is completely dry
to touch, wait an additional 48 hours before contact or use in
any other waterway.
For all commercial fishing operations the following procedures should
be followed:
1. For cleaning gear, use water sources which are known to be clean such
as town supply or bore water from home base, or if not possible use water
from the area to be fished.
2. After completion of fishing, all fishing equipment including nets and
storage containers must be flushed with cleaning solution – 2% mix of
3. All clothing ie: gloves, overalls, boots etc must be either left to dry for 48
hours or washed in 5% solution from above list before entering another
4. Spray down vehicle in particular underneath and around tyres etc with 2%
mix of bleach or other solutions outlined in 2. above.
When applying the above cleaning methods, it is recommended that you:
?? Use biodegradable products
?? Do not wash cleaning waste into waterways
?? Choose a cleaning solution from the above choices that will not adversely
effect your equipment.
?? Follow manufacturer’s safety instructions when using products.
5. Jet boats must be cleaned down in same manner before
entering another waterway. Also the grill and heat exchange
South Island Eel Industry Association: Eel Management Plan September 2009
must be checked for clumps of didymo. Sand trap must be
emptied and left to dry for 48 hours before entering another