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FISH QUESTIONNAIREDeep-sea fisheries commission FranceRponse Matthew DUNN (NIWA, NZ)

(11/03/2010)

FOR ALL

1. Could you please send us a short bio (less than 20 lines)?

Dr Matthew Dunn. I received my PhD in fisheries stock assessment from theUniversity of Portsmouth UK in 1999. After Portsmouth University I worked at CEFAS(UK) on the stock assessment of various inshore species, including substantial timespent at sea on research and commercial fishing vessels. In 2003 I moved to theNational Institute of Water & Atmospheric Research (NIWA) in New Zealand, to workon deepwater fisheries. My main focus for the last 7 years has been stockassessments for several different deepwater fishes (orange roughy, oreos,cardinalfish, and others). My current research includes studying deep sea fish biologyand population dynamics, describing and understanding the fisheries, and conductingquantitative stock assessment modelling, including the provision of managementadvice to the NZ Government. I am also involved in research planning processes inNew Zealand, and spend some time studying the ecosystem interactions of deep-seafisheries. I have been the manager of the deepwater fisheries group at NIWA since2004, and lead NIWAs deepwater stock assessment research.

Do you know of anyone having compiled or in the process of doing so all the

existing (and precise) data on the vulnerability of deep-sea fish?

No.

There are special sets of questions targeting local expertise, but if you could alsotry to answer as many questions from the general questionnaire, it would be muchappreciated.

GENERAL QUESTIONNAIRE

What do you consider the deep sea?

In New Zealand we have a lot of sea, so we consider deep-sea to be >800 m.

How many fish species are known from the deep sea?

I do not know the total number, but we regularly catch ~150 in research trawlsurveys.

How many species are targeted and how many are caught as bycatch?

Four main target species in New Zealand. By-catch tends to be relatively low, butmight include another ~100 species on an intermittent basis.

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How well are deep-sea fishes monitored?On the whole quite poorly. This is largely because of scientific problems.

How much is known about the life history of both targeted and untargeted species?

For the target species the basic biology is known, but details are often lacking (e.g.,connectivity between areas). The biology of most by-catch species is poorly known,and often includes little more than species identification and depth or spatialdistribution from trawl catches.

How much is known about the fecundity, egg production and spawning frequency ofdeep-sea fishes?

Only known for target species, but generally from 1 or 2 studies a decade or moreago.

How much is known about the food and habitat requirements for deep-sea species?

Basics are known for the target species. Otherwise poor knowledge.

Are some deep-sea fish endangered? Which ones? Where? As a result of what?

I doubt any fish are endangered as a species, but I dont think anyone really knowsfor deep-sea fishes. Some stocks are heavily depleted, but this does not necessarilyclassify them as endangered.

Are there deep-sea fish that can be exploited sustainably? Specifically, what aboutblack scabbardfish, blue ling, or grenadiers?

In principle all fish could be exploited sustainably, but I dont know for these particularspecies.

What proportion of known deep-sea fish species could support a fishery?

All could support some form of fishery. The question is how big will the fishery be? Acatch of 1 tonne per year would be no problem but 1 t per year would not be an

economic possibility! It is a balance between sustainability, taking a precautionaryapproach, and the economics of harvesting.

Do we know enough about deep-sea fishes in general to manage them rationally?

Yes, we can manage them rationally. But I am not sure we know enough to managethem in a way that can be scientifically demonstrated to be sustainable. For thescience, finding n cost-effective monitoring tool is the main problem. I dont know ofany deepwater fisheries that would, at present, pass Marine StewardshipCertification.

What indicators might be used to show possible decline of fish populations?

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Biomass survey estimates are the main tool. These can be acoustic or trawl (orboth). Surveys would be better than using commercial catch rates (catch rates canbe very biased for some species). Length frequencies and age structure can be usedto monitor future production (recruitment), but would probably require researchsurveys (to go to the areas where juveniles may be found, which are often not the

commercial fishery areas).

Can the same approach that is used to manage shallow water fisheries be used tomanage deep-water fisheries?

In principle, yes.

Are some fishing gears worse than others for vulnerable fish populations?

Trawling is the worst. Most deepwater fishing uses trawls.

What is the likelihood that release from fishing pressure will allow fish populations torecover? And ecosystems to recover?

A high likelihood, given a long enough timespan - a closed orange roughy fishery inNew Zealand has recently shown signs of recovery after 10 years. Ecosystemdamage from trawling can be substantial, and is likely to take longer to recover.

Is it likely that the depletion of deep-sea fish populations will have an effect on thedeep-sea ecosystem?

Almost certainly, but there is no scientific proof of this yet (as far as I am aware).

I have heard some emotive speeches from scientists about the terrible impact ofdeep-sea fishing on ecosystems, but I think from a true scientific point of view manyof these comments cannot be supported (the truth is there isnt enough research yet,and so we simply dont know).

Would the establishment of deepwater marine protected areas (MPAs) be a usefulstep?

Yes, if carefully designed and implemented. MPAs are probably more important for

biodiversity than for sustainable fisheries. It also depends on the effectiveness ofother management tools (e.g., catch quotas, net designs etc).

Would more science help management? How much science? At what cost? Does thelanding value of deep-sea fishes justify the deployment of scientific programs in yourview?

Deepwater fisheries research is very expensive, because of the extensive need fordeep-water research vessels. New Zealand has spent over 50 million euro ondeepwater scientific research over 20 years and although great progress has beenmade, New Zealand has still not been able to answer all of the questions necessary

to demonstrate sustainable deep-sea fisheries. Even reliable stock monitoring toolshave proven very difficult to find, and this research is ongoing. Certainly, the food

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resource that comes from deep-sea fishing does not, in my view, justify the scientificresearch and costs. In some cases the economic value may justify the cost. The NewZealand deep-sea orange roughy fisheries are the largest in the world, and I doubtmany smaller fisheries elsewhere would be able to justify the level of scientificresearch required.

Will science be able to find out enough about deep-sea fish and ecosystems in time,considering current exploitation rates?

This is hard to know. I want to say yes, but I suspect the true answer may be no.

How do you envisage the future of deep-sea fisheries, by the year 2015 for example?

By 2015 I dont think things will be that different. But perhaps by 2020, I can envisagelarge-scale fisheries will be finished, and any remaining fisheries are likely to beboutique fisheries. Public consumer pressure is likely to stop many fisheries, and

only those that can demonstrate some level of sustainability (e.g., using MarineStewardship Certification) are likely to prosper. I believe most deepwater fisheries willnot be able to achieve this level of certification.

Telmo MORATO

About the monitoring of trawl ban and its effects on fisheries:

When was the trawl ban decided and then implemented?

What drove that decision?

What has been the impact of the trawl ban on fisheries?

How many boats did it concern?

Is it experienced as a positive or negative thing by fishermen? Scientists?Politicians? The public?

What kind of deep-sea fisheries go on in the Azores?

Since when?

Size & amount of boats ?

Amount of fishermen ?

Where do they work (far from land ? Close?) and how (technique + gear used) ?

How many fishermen lost or gained to the trawl ban?

What landing volume of deep-sea fish?

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What targeted species?

Are they mainly for local consumption or exports?

Who assesses the status of the targeted deep-sea stocks?

Are fishing objectives or quotas set for this type of fisheries and species (same asE.U quotas?)

Shark special : Bernard SERET & Sarah FOWLER

What are the main targeted / untargeted shark species caught by bottom trawlersworking in the deep sea?

What are the main targeted / untargeted shark species caught by longlinersworking

in the deep sea?

What is known about the decline of deep-sea shark species because of fishing?

What markets exist for deep-sea sharks (% for meat vs % for other products)?

New Zealand Special

What deep-sea fish species are NZ deep-sea fisheries made of? and for whatcorresponding landings since the beginning of each fishery ? (Its interesting for ourcommission to have a global view of the evolution since the beginning of fishing).

Details of the history of the New Zealand fisheries are available from the NZ Ministryof Fisheries website. Briefly:

Orange roughy. The fishery for orange roughy started in the late 1970s. During the1980s large aggregations of spawning fish were found to the east, and west of NewZealand, and a fishery rapidly developed. There was then a period of fishing downthe stocks to a size estimated to give MSY. Catches peaked at about 50,000 t peryear in the mid to late 1980s. Catch quotas were then reduced, and catches

decreased. Since the mid 1990s catches have been about 15,000 t per year. Thereare now 8 management stocks around New Zealand, of which 3 are effectivelyclosed at present after the stocks were estimated to be over-exploited. Orangeroughy has always been the primary target species for deep-sea fishing in NewZealand.

Black oreo. Oreos are also known as deep-sea dories. Black oreo was first fished inthe early 1970s, and catches peaked in the early 1980s at about 10,000 t per year.Quotas were introduced and catches were reduced in the late 1980s. In recent yearscatches have been about 5,000 t per year. Both black and smooth oreo are foundand targeted primarily to the centre and south of New Zealand, whereas orange

roughy are more northern.

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Smooth oreo. Like black oreo, smooth oreo was first fished in the early 1970s, andcatches peaked in the early 1980s at about 10,000 t per year. Quotas wereintroduced and catches reduced in the late 1980s. In recent years annual catcheshave been about 8,000 t per year. There is an indication that biomass levels arecurrently increasing the largest stock, following a period of good recruitment.

Black cardinalfish. Black cardinalfish are occasionally targeted, but are a secondarycatch to orange roughy. Catches peaked at about 4,000 t in the mid-1990s. Catcheshave generally not been restricted by the quotas. Recent catches have been about2,000 t per year. A stock assessment in 2008 estimated the main stock to besubstantially depleted, and catch quotas are being now reduced to ~1500 t (for themain stock, the quota reduction is from about 2200 to 500 t).

NZ deep-sea fisheries are sometimes referred to (by some at least, not all) as apotential model of sustainability, can one say that deep-sea fisheries in NZ aresustainable?

No, at present it is not possible to prove scientifically that they are sustainable.

Note here that I am referring to deep sea (>800 m) fishes. The science has shownthat some of the stocks we refer to as middle-depths (200-800 m), which might becalled deep-water in other countries, are being managed sustainably.

By which standards?

New Zealand harvest strategy rules.

Do these standards aim for MSY as well as the conduct of fisheries according to anEcosystem-Based approach?

Yes, they aim for MSY. The MSY has been estimated to be about 30-40% of virginbiomass. There is a soft limit when current biomass reaches 20% of virgin biomass(= rebuilding plan), and a hard limit at 10% virgin biomass (= closure).

The ecosystem approach in NZ currently primarily concerns by-catch of seabirds andcetaceans, and these impacts are well managed and have been minimised. Whilstthere is some research on other ecosystem effects (e.g., benthic impacts of trawling),

considering these is, at present, not clearly influencing fisheries behaviour ormanagement.

What is the % of biomass taken on each targeted stock?

This is often poorly known, and not often reported because the management systemdoes not require it.

However, the new harvest paradigm for orange roughy has the catch set to thecurrent estimate of mature biomass multiplied by natural mortality (4.5%), i.e., fishingmortality equals natural mortality.

How do you estimate the stock?

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Either through Bayesian stock assessment models, which integrate information fromcatches, fishery-independent biomass indices or absolute biomass estimates,commercial catch rate indices, age and length information etc. Alternatively, directlyusing acoustic estimates of absolute biomass, with catches set as 4.5% of the

current estimated mature biomass. The latter approach only works well under limitedcircumstances (large and stable single-species aggregations on flat seabeds underother circumstances the acoustic method does not work well).

Have the models used since the beginning proven to be solid?

No. The stock assessment model for the east and south Chatham Rise orangeroughy, the largest stock in NZ, was rejected in 2008. There is now no stockassessment model for this stock. This was because the model could not explain theobservations. Also, the model predicted a biomass rebuild which was not being seenin the real world. This problem is being seen across most of the other stocks as well.

The stock assessment model miss-fit was the stimulus for changing the managementparadigm, moving to a harvest rule of catch = 4.5% of current mature biomass, wherecurrent biomass is estimated from acoustic surveys. This approach is now beingconsidered for all orange roughy stocks, basically because the current stockassessment models dont work.

The observational data for orange roughy, oreos, and cardinalfish, all show similarpatterns that the current models cannot explain a number of assumptions havebeen made to make these problems go away, but the solutions are unsatisfactory,and as a result, all of the models lack credibility. Research to try and make the stockassessment models work, and explain the observational data, is an ongoingresearch topic.

How can we know the future of a fishery and the behaviour of a stock for species withhigh longevity and unknown fecundity rates ?

Difficult. The best option might be to use Management Strategy Evaluation todetermine harvest rules that are robust to the life history patterns of long-livedspecies, robust to the uncertainties in our understanding of the stock dynamics, androbust to uncertainties in our stock monitoring and stock assessment tools. In the

face of all of the uncertainties, the best harvest rules are likely to be indicate veryconservative catch levels indeed (i.e., very small catches are the only way to have asafe fishery).

How can NZ fisheries prevent impact on habitats and untargeted species? (Since NZclosures analysis shows the vast majority of them are beyond fishable depths.)

This note is correct, in that the benthic protected areas currently do not impact orprotect any of the fisheries. The industry and government would argue that they werenot meant to they were intended to protect non-impacted areas.

The only way to prevent impacts is to remove the impact. In NZ, this is currently notdone. The benthic protected areas agreement is due for review next year, but it

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remains to be seen whether MPAs to protect fish stocks will be considered.

How do you envisage the future of NZ deep-sea fisheries? Has a trend becomeclear?

Consumer choice is having an increasing impact on the fishing industry, with manyoverseas markets now refuse to buy deep-sea fishes from New Zealand. The currentresponse in New Zealand seems to be to reduce the orange roughy fisheriesconsiderably, and try and develop harvest strategies that will be able to satisfyindependent schemes such as Marine Stewardship Certification. This would allow theindustry to say their fish are certified, and so ok to eat. But the likely result of this is adeep-sea fishing industry that is smaller than at present, and very much smaller thanit has been in the past. The fishery would then be more of a boutique species,hopefully commanding a high market price. If this cannot be done, then I envisagethat the industry will not exist.

How has the fishing industry coped or retargeted its fishing effort if theres beenmajor decreases in certain fisheries?

The fishing industry has obviously resisted catch quota reduction in some cases,including legal challenges to the scientists and ministry of fisheries to try and rejectthe stock assessment results. But now I believe the industry recognises the inherentproblems with deep-sea species, and is slowly recognising that they will not be theimportant fisheries they were in the past. The excess fishing effort has relocated toother New Zealand fisheries, or the vessels have been sold overseas. Some of thevessels were chartered from overseas originally (effectively flag ships), and soreducing the catches and effort simply meant the New Zealand companies did notrenew their charter arrangements. The New Zealand government has not providedany subsidies (as far as I know) for the removal or reallocation of fishing vessels orcrews.

Specific for Tracey SUTTON & Jeff DRAZEN

Do pelagic fishes show different resilience or vulnerability than demersal fishes?

How much known about their life cycle etc (see questions below)

Do you know of fisheries targeting deep-sea pelagic fishes?

Which ones? Where? For food, for fishmeal or for oil? (Like Myctophids in SouthAfrica).

Do you have a recommendation of a (few) name(s) we could send a specificquestionnaire about midwater fisheries to?