..

I

J

'1

~"

~

edited by

Prof. Tony .l Pitcher

and

Rat/ana (Ying) Chuenpagdee

published by

~!:t

;;I

The Rsheries Centre, University of British Columbia

~j.~204 Main Mall

Vancouver, B.C, Canada

~~

ISSN 1198-6727

",,J

TABLE OF CONTENTS

..1

Director's ForewordTony J.Pitcher

Workshop Agenda , 3

Section I: Ecological and Economic Impact of Bycatches on Fisheries

Session SummaryPeter Larkin 5

The bycatch problem from an economic perspectiveJoe Terry 6

Bycatch mortality impacts and control for Pacific halibutBroce Leaman ""'"

,

14

Three proposed solutions to bycatc:h and discard in the North Pacific:focus on the U.S. rocksole fishery

John Gauvin and Joe Blum .23

Section II: Bycatches and Trawl Fis,heries

The Pacific ground fish trawl fisheries: bycatch problem and potential solutionsBany Ackerman 31

Research and development efforts in bycatch elimination intrawl fISheries of British Colwnbia

Douglas March 31

Development of by-catch reducing trawl gears in NSW's'prawn trawl fisheriesSteven Kennelly 33

Use of a semi-pelagic trawl in a tropical demersal trawl fisheryDavid Ramm ..39

Section III: Bycatches and Passive (;ear Fisheries

World bycatches of sharks in high-seas fisheries: appraising the waste of a resourceRamon Ronft/ 41

Management of bycatch in hook-aDd-line groundfish fisheries off Alaska.Janet Smoker 45

.49

Bycatch of steelhead (Oncorhynchus mykiss) and coho (0. kisutch)in the Skeena river sockeye (0. nerka) fishery

Joel Sawada and Art Tautz

Section IV: Bycatches and Purse-seine Fisheries

Bycatches in purse-seine fisheriesMartin Hall 53

Bycatch in B.C. purse-seine fisheries: recent experiences insouth coast chum sahnon fisheries

Paul Ryall 59

Reducing bycatch through gear modifications:the experience of the ttma-dolphin fishery

Harold Medina 60

Section V: Towards solving the bycatch problem ~-;,;

.JBycatch strategies: some success stories and promising approaches

Brad Warren 61

A classification of bycatch problems and. some approaches to their solutionsMartin Hall. 65

Section 6: Summary of working groups

TechnologySteve Kennelly. 75

Policy and AttiwdesAndrew Trites 78

List of Participants 79

Fisheries Centre Workshop Series 85

ill

~:]

I

,;j

~i';,

,.;;It

1

DIRECTOR'S FOREWORD development. Conservation groups focus on suchiniquities as evidence of irresponsible fishingdriven by greed, multinational corporations andevil fisher folk. To make matters worsemortality of marine mammals and turtles as by:catch in commercial fisheries enragesconservation groups and large sectors of thegeneral public. This workshop was held toestablish some of the facts about by-catch,discuss how its adverse effects might bemitigated, and try to determine whether thedifferent perspectives of the fishing industry, fishecologists, conservationists and policy makers onthis issue might be reconciled.

Academic fishery researchers, fisheries graduatestudents, government fishery scientists, fisheriesconsultants and a commercial fishermen gatheredat the Fisheries Centre at UBC on October 13thand 14th 1994 in order to discuss the probleIDSof by-catch. 51 participants came from BritishColumbia, Washington, Alaska, California,Mexico and Australia. This comprises the 3rdreport in the UBC Fisheries Centre's ResearchReport Series.

There is little doubt that. for conventionalfisheries and the existing spectrum of species.the sustainable marine world fish catch hasreached its limits of around 80 million tonnesper annum. It is not surprising therefore that wehear growing public concern at the amount ofdiscarded by-catch in world fisheries. C1Jrrentlyestimated at around 30%. That one tonne offishin every three caught is tipped back into the seais perceived as a waste of fish and of fishingactivity in a world short of protein for humannutrition and rife with demands for economic

Discards are large and widespread in tropicalfisheries for high value species like prawns,where in the worst examples in South East Asiaas much as ten tonnes of small fish are discardedfor every tonne of prawns landed. Fish that arecaught below legal size limits of target speciesare commonly discarded, for example in purseseine fisheries for mackerel in Europe, a practiceknown as 'high- grading' (Figure 1). It is asurprise and a paradox that large by-catch

--TOTAL MORTALITY i~ ~.

encounter, with gear

u(~~~;~) itarget 'species I

._.~~;=r:rs.d1ffl,Z~

~

high--gratiing

FISH STOCKSof..-

alive

By-<;atch: by Hook and by CrookFigure

2

discards are endemic in many intensivelyresearched and managed fisheries in NorthAmerica, and that these discards occur as adirect consequence of complex and we] 1-considered regulations supporting policiesdevised to avoid depletion.

problems, while the final section comprisessummaries of the discussions on ecological andeconomic impacts, technological solutions andpolicy and attit.udes to bycatch that werepresented following discussions among threeworking groups at the workshop. I

Operational reduction of bycatch through morecareful fishing practice, in tandem withincentives to vessel skippers and crew, is onedevelopment presented here that has significantlyreduced bycatch in tuna fisheries. TecbniC4l1solutions may be found lie in the improvement ofgear design to allow target species to escape thegear and survive but this simple objective oftenturns out to be not as simple as might bethought. Figure I illustrates schematically whathappens when fish encounter fishing gear. Fishmake a series of be havioura I decisions that resultin evasion, escape or capture. Most fishing gearshave traditionally been designed to maximisecapture~ and so the technical challenge inreducing bycatch is to identify key behaviouralcomponents of this system that may selectivelyrelease or allow the escape of fish that are toosmall or of the wrong species. Several solutionsof this kind were presented at the workshop.Nevertheless, even with technical advances inthe design of fishing gear, some bycatch isinevitable, and at the workshop there wa.c;discussion of the idea that we have to learn toaccept that trade-offs have to be made, even withmarine mammal deaths, if fISheries are to bemanaged optimally and sustainably.

In contrast to the atmosphere of gloom andforeboding that seems obligatory at manyworkshops on fisheries problems these days,most of the participants were generally moreoptimistic at the end of the workshop than at thebeginning. Hopefully, this was not just onaccount of the convivial atmosphere that isassociated with Fisheries Centre workshops, andis a portent of reasonable solutions may soon bedevised to the bycatch problem.

Tony J. PitcherDirector. Fisheries Centre UBC. Vancouver

'{

1~

~.,

~

:1

.~

~:j

c ~

An analysis of bycatch may distinguisl1ecological, technological, economic and policydeterminants, with consequences and candidateremedies that may be associated with each of'these categories. This report commences with asection devoted to a review of ecological andeconomic factors, followed by reports on twoimportant North Pacific fisheries. Subsequentsections then discuss bycatch in three differenttypes of fishing gear: trawls, purse seines andpassive gear such as long-lines. Technicaldevelopment of selective trawl and purse seinegears is evaluated and case studies presentedfrom Australia, British Columbia, Alaska andMexico. There is also a review of by-catchproblems affecting world shark populations.Section 5 presents progress towards a generalclassification and strategies for solving bycatch

J

%J

,;:1~iI

.~

,"

..~

cl,.:~,,;~~

3

WORKSHOP AGENDA

13 October 1994

8:15 -8:458:45 -9:00

Registration & Continental BreakfastWelcoming and Opening AddressBycatch in Fisheries: By Hl)Ok and By CrookTony Pitcher, UBC Fisheries Centre

Session 1: Ecological and Economic Impact of Bycatches on Fisheries

9:00 -9: 10

9:10 -9:30

9:30 -9:50

9:50-10:10

General IntroductionPeter Larkin, UBC, North Pacific Universities Marine Mammal Research ConsortiumThe bycatch problem from an economic perspectiveJoe Terry, NMFS, WashingtonBycatch mortality impacts alld control for Pacific halibutBruce Leaman, PBS, NanaimoThree proposed solutions to bycatch and discard in the North Pacific: focus on the U.Srocks ole fisheryJohn Gauvin and Joe Blum, .4merican Factory Trawler AssociationCoffee Break10:10-10:30

Session 2: Bycatches and Trawl Fisheries

10:30-10:40

10:40-11:00

11:00-11:20

11:20-11:40

11:40-12:00

General IntroductionDayton L. Alverson, Natural Resources Consultants, Inc.,WashingtonThe Pacific groundfish trawl fisheries: bycatch problem and potential solutionsBarry Ackerman, DFOResearch and development efforts in bycatch elimination in trawl fisheries of BritishColumbiaDouglas March. Deep Sea Trawlers Association of B.C.Development of by-catch redllcing trawl gears in NSW's prawn trawl fisheriesSteven Kennelly, NSW Fisheries, AustraliaUse of a semi-pelagic trawl in a tropical demersal trawl fisheryDavid Ramm, Dept. of Primary Industry and Fisheries, Damin, AustraliaSandwich lunch (in Ralf r orq;ue Room)12:00 -1:00

Bycatches and Passive Gear FisheriesSession 3:

1:00-1:10

1:10 -1:30

1:30 -1:50

1:50 -2:10

General IntroductionAndrew Trites, UBC, North Pacific Universities Marine Mammal Research ConsortiumWorld bycatches of sharks in high-seas fisheries: appraising the waste of a resourceRamon Bonfil, UBC Fisheries CentreManagement of bycatch in hook-and-line groundfish fisheries off AlaskaJanet Smoker, Fisheries Info. ..S'erviceBycatch of steelhead (Oncorhynchus mykiss) and coho (0. kisutch)in the Skeena riversockeye (0. nerka) fisheryJoel Sawada and Art Tautz, B.C. Provincial Fisheries Branch

)iI4

Session 4: Bycatches and Purse-1>eine Fisheries

2:10 -2:20

2:20 -2:40

2:40 -3:00

3:00 -3:203:20 -3:40

3:40 -4:00

,

':,§4:00 -4:20

4:20 -5:30

General IntroductionMartin Hall, Inter-Americtln Tropical Tuna CommissionBycatches in purse-seine fisheriesMartin Hall, Inter-American Tropical Tuna CommissionBycatch in B.C. purse-seine fisheries: recent experiences in south coast chum salmonfisheriesPaul Ryall, DFOCoffee BreakReducing bycatch through gear modifications: the experience of the tuna-dolphin fisheryHarold Medina, CaliforniaBycatch strategies: some success stories and promising approachesBrad Warren, National Fisherman, WashingtonA classification of bycatch problems and some approaches to their solutionsMartin Hall, Inter-American Tropical Tuna CommissionSummary of Day One (identification ofmqjor issues to be addressed on Day Two)

14 October 199~J

.

i;

9:00 -12:001:00 -2:00 -4:00

Parallel sessions of working groups, addressing major issues identified on Day One.Sandwich lunch (in RalfYorque Room)Chair of each working groups report to the full meetingFull meeting discussion and summary I Discussion of possible publication.Adjourn -

~

~

;;~

:.'-~~.:~

~;.~~

~.~

j

;~,,~

12:00-1:00

2:004:00

SECTION

ECOLOGIC:AL AND ECONOMIC IMPACTOF BY'CATCHES ON FISHERIES

5

lerns of monitoring and enforcement. Ecologicalimpacts are not readily assessed because there isno routine monitoring of abundance of non-targetspecies. The relative abundance of target andnon-target species is important in determiningthe severity of the bycatch problem.

SESSION SUMMARY:

ECOLOGICAL AND ECONOMIC IMPACTOF BYCATCHES ON FISHERIES

Peter Larkin, North Pacific Universities MarineMammal Research Consortium, Room 18, HutB-3, 6248 Biological Sciences Road, Varlcouver.B.C. V6T IZ4. Canada.

John Gauvin and Joe Blum presented solutions tothe rock sole bycatch problem in the Gulf ofAlaska: increasing mesh size, increasing reten-tion rates, establishment of individual transfer-able quotas (ITQs) with tradeable rights tobycatch. The measures would reduce thebycatch from a fishery that targets on femaleswith roe.

...

Because fisheries management has focused onstatistics of landings the effect of bycatches onmarine ecosystems and on the economics offisheries operations has not been given sufficientattention. It has been estimated by Alvt:rson etal (1994) that the world marine fisheries c;atch of83 million tonnes may be 30% less thaI) actualcatch.

Discussion was c.ombined with that of sessiontwo and underlined the uncertain nature ofecological impacts. Except for historical data onfisheries recently developed there is little infor-mation on pristine relative abundance of species.Changes in abundance of non-target species maybe available from research cruises but the selec-tivity of gear makes even these data unreliableindices.

The ecological effects include mortality ofdiscards of undersize, -wrong sex or otherwiseunwanted individuals of target species, inc:identalmortality to desired but non-target species, readyavailability of food to scavenging speci<~, anddifferential effects on the interactions betweenspecies in fish communities with possible rever-berations through community structure.

The view was unanimous that greater attentionshould be given to bycatch issues if managementis to take better account of the ecological andeconomic issues involved.

Economic issues include the loss of time insorting the catch, the costs of selective gear orrestrictions on time and area of fishing, the costsof retaining the bycatch and its value if landed.

The economic perspective on bycatch was suc-cinctly presented by Joseph Terry of the AlaskaFisheries Science Centre. Bycatch is an econ-omic problem "if it precludes other highervalued uses II and "if there are costs associatedwith actions to reduce bycatch It. His analysisrelated the marginal costs and benefits to thelevel of bycatch mortality from the perspectivesof the individual fisher and of society. Theecological impacts are not readily quantified ineconomic terms.

Bruce Leaman described the bycatch problem ofthe trawl fisheries of Alaska and British Colum-bia with particular reference to the bycatch ofhalibut. The market for the bycatch of manyspecies and sizes is limited. For valued speciessuch as halibut, quotas or trip limits pose prob-

,J

6

THE BYCATCH PROBLEM FROM ANECONOMIC PERSPECTIVE

The net benefit to the Nation is equal to thedifference between the total benefit (value) of theoutputs and the total cost (value) of the inputsassociated with the uses of fishery resources.Costs and benefits should be defined broadlyfrom the Nation's perspective to include thosethat accrue to direct and indirect participants inthe fishery as well as to other members ofsociety.

Joseph M. Terry, Alaska Fisheries ScienC(~Center, National Marine Fisheries Service..NOAA FlAK C2, 7600 Sand Point Way NE.Seattle, WA 98115, USA

ABSTRACT

The inputs used in a commercial fishery includefish taken as target catch and bycatch; otherliving marine resources; the fishing vessels.gear. and bait used in harvesting; the plants orvessels. equipment. and materials used forprocessing; and the fuel and labor used through-out the production process. The cost of eachinput should be measured in terms of its oppor-tunity cost which is the net benefit foregone inits highest valued alternative use. Because eachuse of a fishery resource is associated with adifferent combination of inputs and outputs.alternative uses cannot be ranked in terms of netbenefits without considering the values to theNation of all the inputs and all the outputs ofeach use.

Bycatch occurs whenever fishing gear is notperfectly selective. Bycatch is a problem if itprecludes higher valued uses of fish and otherliving marine resources and if there are costsassociated with actions to reduce bycatch. If theformer condition is not met, there is not a prob-lem. If the latter condition is not met, thesolution to the problem is trivial. There are tworelated issues that should be considered in deter-mining how to control bycatch. They can bestated in tenns of the following two-part ques-tion. What are the appropriate levels of bycatchand why are those levels being- exceeded? Boththe benefits and costs of decreasing bycatch areimportant in determining the answer to each partof this qu~tion, in comparing the extent of thebycatch problem among fisheries, and in evaluat-ing fishery management alternatives intended toaddress the bycatch problem. This paper isbased on a three part series of discussion paperson proposals currently under consideration bythe North Pacific Fishery Management Councilto address the problems of bycatch, discard, andthe utilization of catch in the groundfish fisheriesoff Alaska.

1

The net benefit of the use of fish in a commer-cial fishery and its distribution are determinedjointly by the answers to the following fourquestions:

1. How much fish is removed eachyear by the fishery?

2. How is it removed?3. By whom is it removed?4. For what purposes is it removed?

...

The answers to these questions are detenninedby the decisions made by individual fishennenand processors in response to a variety of incen-tives and constraints that reflect the economic,social, regulatory, biological, and physicalenvironments in which they operate.

The objective for fishery management is toincrease the contribution of fishery resources tothe well-being of the Nation. This can be doneby increasing the total net benefit resulting fromthe use of fishery resources and by improving itsintra-temporal and inter-temporal distributions.The uses of these resources are not limited todirect consumptive uses by man. In the case ofa stock of fish, the uses include being taken ascatch and bycatch in a variety of fisheries andfor a variety of purposes, providing prey forother living marine resources, acting as pred-ators, and contributing to the future size of thatstock of fish.

Each of these four questions is intended toencompass a range of questions. The firstquestion addresses not only total removals butalso the size, age, sex, temporal, and spacialdistributions of the removals. The secondquestion addresses the cost of all the inputsassociated with a particular method of harvestingfish. The third question is intended principally

ill

to address a range of distribution questions. Thefourth question addresses both the cost of all theinputs associated with the use of catch and thebenefits of those uses.

attention as has the bycatch of crab in the BSAIcrab fisheries.

There are two related issues that should beconsidered in determining how to controlbycatch. They can be stated in tern1S of thefollowing questions:

The amount of fish removed (used) by fishermenis total fishing mortality. In addition to fishingmortality accounted for by retained (:atch, itincludes the fishing mortality resulting from thefollowing: discarded catch; lost gear; and otherdirect interactions of fish with fiShermen, fishingvessels, or their gear. Often it is difficult toobtain good estimates for the removals accountedfor by retained catch and even more difficult todo so for the other components of fishing mor-

tality.

2

What is the appropriate level ofbycatch?Why are there currently excessivelevels of bycatch?

Each question is answered below.

What is the a~~ro~riate level of bvcatch? Acommon response to this question is that nobycatch is the appropriate level. Some modifythis response to say that the lowest level ofbycatch practicable is appropriate. This modifi-cation recognizes that it may not be technologi-cally possible to eliminate all bycatch withouteliminating some very important fisheries. Thismodification is a step in the right direction.However, unless the definition of "practicable"is extended to consider the costs, as well as thebenefits, of decreasing bycatch, that response isalso incorrect in tenDS of increasing the netbenefit to the Nation from using fisheryresources. Basically, it makes sense to reducebycatch in a cost effective manner to the level atwhich further changes would increase costs morethan they would increase benefits. If cost effec-tive methods are not used to decrease bycatch,the point at which the additional costs exceed theadditional benefits will be reached at a higherlevel of bycatch.

The at-sea and on-shore observer program andproduct weight monitoring program for theBering Sea/Aleutian Islands (BSAI) and Gulf ofAlaska (GOA) groundfish fisheries in the USEEZ provide better estimates of catch. bycatch.discards. and the use of retained catch andbycatch for these two fisheries than are availablefor most other fisheries. Although the bycatchrates vary significantly among individual compo-nents of these two fisheries. the overall bycatchrates in these two fisheries are not high com-pared to those in many fisheries. However.these rates result in levels of bycatch that arehigh compared to those in many fisheries due tothe sheer magnitude of the BSAI and GOAgroundfish fisheries. In 1993. estimated totalgroundfish catch in the BSAI and GOAgroundfish fisheries was about 2.148.000 metrictons (t) and estimated groundfish discards were348.000 t for an average discard rate of 16.2%(Table 1). For the BSAI fisheries. the 1993discard rates ranged from 4.5% in the pelagicpollock trawl fishery (Table 2) to 69% in therock sole trawl fishery (Table 3).

The marginal benefit and marginal cost curves inFigure 1 present graphically the concept of theoptimum level of bycatch. The marginal benefitcurve depicts the marginal (or additional) benefitof reducing bycatch mortality by one more unit.Similarly, the marginal cost curve depicts themarginal (or additional) cost of reducing bycatchmortality by one more unit. When there arehigh levels of bycatch and little has been done tocontrol bycatch, there are probably some simpleand low cost actions that can be taken to reducebycatch. However. at some point, the simpleand low cost methods of reducing bycatch willbe exhausted and more difficult and costlyactions would be necessary and extreme

In response to concerns about the levels ofbycatch in the BSAI and GOA fisheries, theNorth Pacific Fishery Management Council(Council) has recommended and the Secretary ofCommerce has approved and implemented avariety of management actions that wereintended principally to control the bycatch ofhalibut, crab, herring, and salmon in theground fish fisheries. Recently, the bycatch ofgroundfish and the utilization of the catch andbycatch of groundfish have received increased

8

measures may be necessary to eliminate the lastfew units of bycatch. Therefore, the marginalcost curve is expected to slope down to the right.The marginal benefit curve is expected to slopeup to the right for the following reasons. Atvery low levels of bycatch, most of the fishingmonality of the species taken as bycatch isaccounted for by other fisheries and the netbenefit of some of the uses of that species inthose other fisheries probably is quite low.However, at very high levels of bycatch, muchof the fishing mortality of that species isaccounted for by the bycatch and the lowervalued uses in other fisheries would have beeneliminated. As a result, the opportunity cost ofa unit of bycatch which is the marginal benefit ofreducing bycatch would be high.

managed. Experience and economic theorydemonstrate that, in an open access fishery, eachfisherman has incentives to make decisions thatresult in the wrong answers to the four questionsthat jointly determine the level and distributionof the net benefit generated by a commercialfishery. Generally, too much fish will beremoved and, due to the answers to the last threequestions, the cost of inputs will be unnecessar-ily high and the value of outputs (benefit) will beunnecessarily low for each given level ofremovals.

J

'1

The source of the problem principally is that inmaking decisions each fisherman is motivated byhis expectations concerning the benefit he willreceive and the cost he will bear but his deci-sions can result in benefits and costs for others.These externalities (i.e., benefits and costs thatare to some extent external to the fisherinan -andhis decision making process) result in individualfishermen making decisions that collectivelydecrease the net benefit generated from the useof fishery resources.

1

If the marginal benefit and cost curves captureall benefits and costs to the Nation, the appropri-ate level of bycatch is that at which the marginalcost and marginal benefit are equal. In thisexample, marginal cost and marginal benefitboth equal $10 when bycatch equals 10,000. Atlower levels of bycatch, the marginal cost ofreducing bycatch is greater than $10 and themarginal benefit is less than $10; therefore,reducing bycatch below 10,000 units woulddecrease net benefit. However, at higher levelsof bycatch, the marginal cost is less than $10and the marginal benefit is greater than $10;therefore, net benefit would be increased bydecreasing bycatch.

The source of the problem is depicted in Figure3 in which MBF and MBS, respectively, are themarginal benefits curves for a fisherman and forsociety at large including the fisherman. Fromthe fisherman's perspective, it makes sense forhim to control bycatch up to the point at whichhis marginal benefit and marginal cost of reduc-ing bycatch are equal. In this example, MBFand MC are equal when bycatch is 200.Because the marginal benefit curve for society(MBS) includes the marginal benefit -to thefisherman and to the rest of society and becausethe rest of society also benefits from a reductionin bycatch, MBS is above MBF and the optimumlevel of -bycatch for that fisherman fromsociety's perspective is only 150. The externalbenefit results in the fisherman taking too muchbycatch.

The implications of not using cost effectivemethods of controlling bycatch are depicted inFigure 2. MCI and MC2, respectively, are themarginal cost curves when cost effectivemethods are uses and when they are not used.The appropriate level of bycatch is 10,000 unitswhen the cost effective methods are used, but itis 15,000 units when MC2 is the marginal costcurve because cost effective methods are notused.

j

The concept of the optimum level of bycatch aspresented above is quite simple. Applying theconcept can be very difficult due to the difficultyin determining all of the benefits and costs ofdecreasing bycatch. As noted above, the directbenefit of decreasing bycatch is the decrease inthe total opportunity cost of using fish as bycatchand the opportunity cost of a use of fish equalsthe net benefit foregone in its highest valued

Wh~ are there currentl~ excessive levels ofb~catch? A common response to this question isthat the greed or lack of concern by the fisher-men who make decisions on when and how tofish results in excessive bycatch. Perhaps amore thoughtful and productive response is thatexcessive bycatch is but one of the symptoms ofa major flaw in the way many fisheries are

9

alternative use. The alternative uses include:(1) catch in another commercial fishery; (2)consumptive uses in subsistence and recreationalfISheries; (3) contributions to the stock and othersectors of the ecosystem, some of which arenon-consumptive uses; and (4) other non-con-sumptive uses. The value of the fourth includesexistence and option values.

bycatch of one species occurs because bycatch isa multi-species problem in which actions toreduce the bycatch of one species often increasethe bycatch of other species.

The problems of predicting the costs and benefitsof regulatory actions to control bycatch make itdifficult to evaluate either the net Nationalbenefits of proposed regulatory changes or thedistributions of the changes in net benefits.However, these problems do not eliminate therational for attempting to consider both thebenefits and costs of actions to decrease bycatchand to use cost effective methods. The concept-ual framework for determining the optimumlevel of bycatch and for understanding whyregulatory intervention is necessary are useful inevaluating bycatch management alternatives evenwhen accurate estimates and projections of allcosts and benefits are not feasible.

Fortunately, many of the species that: are thefocus of concern are taken as target catch incommercial fisheries. If it is determine<1 that theuse of a specific species as retained catch withadequate utilization is an appropriate use of fishof that species, there is an implicit determinationthat the value of that use is at least as high as thevalue of any use other than in a commercialfishery. If this were not the case, that use wouldnot be appropriate and it should be eliminated.Therefore, the opportunity cost of using such aspecies as bycatch is at most the foregone netvalue of the use that was determined to beappropriate. If the use of a species for bycatchdoes not result in foregone catch for that accept-able use, the per unit opportunity cost may beless than the net benefit per unit of acceptableuse.

Bycatch is a problem when it results in a lowervalued use of a fishery resource. Eliminatingthat use is one solution and increasing the valueof that use is another. The appropriate mix ofthese two solutions will depend on the marginalbenefits and costs of decreasing bycatch and ofincreasing the value of bycatch.

For the living marine resources that are not usedcommercial but that are inputs for a fishery,opportunity costs would have to be estimatedbased on their expected values in other uses suchas their contribution to the value of the ecosys-tem. Such valuations are difficult. The mar-ginal contribution can be positive or negati~e andwe may not know which it is without a substan-tially increased understanding of the ecosystem.Information on the magnitude of bycatch relativeto the biomass of such species may indicatewhether bycatth is expected to have a significanteffect on the contribution of such species to thevalue of the ecosystem. The valuation of theopportunity cost of these non-commercial speciesis important when different management policiesare expected to result in significantly differentlevels of use of these resources (inputs).

The benefits and costs of decreasing bycatch alsoare important in comparing the extent of thebycatch problem among fisheries. Althoughbycatch is typically measured in terms of physi-cal units. such as weight or numbers of animals.aggregate physical measures of bycatch often areof limited use and frequently are misleading.The problem is that the importance or value ofbycatch per physical unit can vary significantlyby species. size. sex. season. and area. Becausean aggregate physical measure of bycatch doesnot account for such differences. it is not usefulin comparing bycatch among fisheries for whichthere are differences in either the ecological oreconomic value per unit of bycatch within oramong fisheries. A value based measure ofbycatch. such as the opportunity cost of usingfishery resources as bycatch. would provide asubstantially more useful measure if both eco-logical and economic relationships are reflectedadequately in the estimates of the opportunitycost of bycatch. With respect to proving mean-ingful comparisons among fisheries, even limitedattempts to account for differences in the oppor-

The cost of decreasing bycatch can be equallydifficult to predict accurately. The range,effectiveness, and cost of changes in fishingstrategies that would decrease bycatch are notknown by the fishery managers. Part of theuncertainty concerning the cost of reducing the

10

tunity cost per physical unit of bycatch couldresult in a substantial improvement compared tostrictly physical aggregate measures of bycatch.Such measures would provide estimates of thebenefits of decreasing bycatch. To compare thepotential net benefits among fisheries of reducingbycatch, the cost of reducing bycatch also has tobe considered by fishery.

I

j~

..~~j

1

jTable 1 Estimated qrcundfish catch and discards (1,000 metric

tons) in the BSAI and GOA qroundfish fisheries, 1991-1994.

BS}.ICatchDiscards, Discarded

19912,127

28513.4

19921,996

31615.8

199228461

21.4

19922,280

37716.5

19931,887

29615.7

1993261

5219.9

19932,148

34816.2

19941,140

18716.4

1994181

2413.0

19941,321

21116.0

1991260

3613.8

GOACatchDiscards, Discarded

BSAJ: and GOAcatchDiscards, Discarded

19912,387

32113.4

~

Note:

~

j

The discard rate estimates that were :alculated usingunrounded estimates of catch and discards cannot all bereproduced exactly using the data provided in thistable.

NMFS Alaska Rec;ion blend esti=ates through July IS,1994.

Source:

:ci

-~

;~

11

Groundfish cAtch and discArds in the BSAI pelAgic pollock trAwlfishery, 1991-1994-

Table 2

Total catch. Di.carded catchMetric ton. Specie. Metric ton. specie. Di.card

compo. it ion compo.ition rAte1991Pollock 680,902 99.2' 50,216 92.4' 7.4'PAcific cod 3,019 .4' 1,806 3.3' 59.8'S&b1efi.h 2 .0\ 2 .0' 96.8'Turbot 63 .0\ 59 .1\ 93.8\Rock 801e 207 .0\ 184 .3\ 88.7'Ye11owfin 39 .0' 31 .1\ 79.6'Arrowtooth 456 .1\ 398 .7\ 87.2\FlAt other 856 .1\ .754 1.4\ 88.1'Rockf18h 68 .0' 52 .1\ 76.9\AtkA mack 0 .0\ a .0' 95.8\Other 878 .1\ 827 1.5' 94.2'Total 686,490 100.0\ 54,330 100.0' 7.9\

1992Pollock 1,295,707 97.7' 80,653 77.2' 6.2'Pacific cod 13.492 1.0' 8,658 8.3'64.2'S&blefi.h 8 .0' 4 .0' 54.8'Turbot 251 .0' 187 .2' 74.4'Rock .ole 3,268 .2' 3,061 2.9' 93.7'Yellowfin 186 .0' 176 .2' 94.7\Arrowtooth 2,798 .2' 2,635 2.5' 94.2'Flat other 5,629 .4' 5,068 4.8' 90.0'Rockfi.h 205 .0' 180 .2' 87.6'AtkA ~ck 242 .0\ 219 .2' 90.5\Other 4.159 .3' 3,695 3.5' 88.8'TotAl 1,325,944 :LOO.O' 104.536 100.0\ 7.9'

1993Pollock 1,227,495 98.6' 41.359 73.0' 3.4'Pacific cod 8,648 .7' 7,052 12.5' 81.5'S&b1efi.h 0 .0\ 0 .0' 15.9\Turbot 67 .0' 66 .1\ 99.6'Rock 801e 2,089 .2' 2.068 3.7' 99.0'rellowfin 579 .0' 556 1.0' 96.0'Arrowtooth 557 .0' 497 .9' 89.2'Flat other 2,659 .2' 2.508 4.4' 94.3'Rockti.h 234 .0\ 227 .4\ 96.9'AtkA mack 35 .0' 34 .l' 98.0'Other 2.346 .2\ 2,252 4.0' 96.0'Total 1.244.710 100.0\ 56.619 100.0' 4.5\

1994-?o110ck 1.185,024 99.0' 20,774 72.7\ 1.8'?acitic cod 8,230 .7' 4,906 l7.2' 5~.5\Sable:ish 2 .0' 1 .0\ 3..5'-:..1:bot .S5 .O' 64 .2' 99.5\Rock .ole 333 .O' 293 :'.0\ 88.2'Ye:low~in 147 .0\ 126 .4' 8~.6\A::oWtooth 956 .1\ 834 2.9\ 8,.3\?:at othe: l.457 .l' 8i8 3.1\ 60.3'Rock:ish 9~ .0' 6~ .2' 66.8'A~~a mac~ 61 .0' 58 .2\ 94.2'Other 713 .1' 563 2.°' 78.9'~otal 1.~91.018 100.0\ 28,5Sa 100.°' 2.4\

~MFS Alaska Regi~n blend e.t~a~e. th:ou;~ Oct 29. 1994.Sou::=e:

~12

Table 3 Groundfi8h catch and di8card8 in the BSAI rock 801e trawl fi8hery,1991-1994-

Discarded catchMetric ton. Specie. Di.card

c~po.ition rate

8,735 32.4' 90.1'1,652 6.1' 38.8'

9 .0' 100.0'1 .0' 100.0'

11,120 41.2' 50.5'1,495 5.5' 73.3'

254 .9' 100.0'2,076 7.7' 79.7'

1 .0' 1.9'3 .0' 100.0'

.1,651 6.1' 97.6'26,998 100.0' 63.3'

9,491 27.8' 91.8'2,108 6.2' 43.9'

------

12,194 35.7' 49.0'2,977 8.7' 61.4'

628 1.8' 99.7'3,620 10.6' 76.6'

22 .1' 97.7'3 .0' 32.3'

3,107 9.1' 99.2'34,150 100.0' 64.0'

17,321 29.7' 93.3'5,632 9.7' 69..0'

3 .0' 68.2'26 .0' 92.9'

23,283 39.9' 58.4'3,799 6.5' 60.5'1,143 2.0' 100.0'4,031 6.9' 55.4'

18 .0' 89.8'8 .0' 53.7'

3,030 5.2' 98.0'58,295 100.0' 69.0\

15,139 27.8' 94.2\3,8a2 7.1\ 61.9'

2 .~\ 12.8\39 .1\ 78.3\

23,654 ~J.3\ sa.5\3,346 5.3\ 73.7\1,74~ 3.2\ lCC.O'3,125 3.7\57.0\

1:5 .2\ 92.9'---3,119 5.7' 98.6'

54.377 100.°' 69.6'

Total catchH.tric ton. Speci..

c~po.ition

9,699 22.7\4,258 10.0\

.9 .0\1 .0\

22,038 51.7\2,040 4.8\

254 .6\2,606 6.1\

46 .1\3 .0\

1,692 4.0\42,646 3.00.0\

10,339 19.4\4,805 9.0\

0 .0\3 .0\

24,866 46.6\4,848 9.1\

630 1.2'4,727 8.9\

22 .0\10 .0'

3,133 5.9\53,384 100.0\

18,573 22.0\8,160 9.7\

4 .0\28 .0\

39,857 47.2\6,277 7.4'1,144 1.4\7,270 8.6\

21 .o,15 .0\

3,091 3.7\84,439 100.0\

16,077 20.6\6,271 a.O\

16 .0'50 .~\

40,419 5:'.7\4,809 6.2\1,744 2.2\5,488 7.0\

125 .2'0 .o,

3,162 4.°'78,161 100.0'

~

ii1

.1

1991PollockPacific codSablefi8hTurbotRock 801eYellowfinArrowtoothFlat otherRockfi8hAtka mackOtherTotal

1992PollockPacific codSablefi8hTurbotRock 801.r.llowfinArrowtoothFlat otherRockfi8hAtJta mackOtherTotal

3.993PollockPacific codSablefi8hTurbotRock 801.YellowfinArrowtoothFlat otherRocktiahAtka ~ckOtherTotal

1.994-PollockPacific codS~l.!iah':",J=~otRock 80!.ev ' 1 #"_e~ ow_J.:\

A::=oWtoothFlat otherRoclc!iahA~ka maCKOt~e=':otal

~M~S Alaska ~eqion ~lend es~~a~e. th~~ug~ Oc~ 29 :'99~So\::=e

~

13

"i9Ur. 1 ft. -~J.na;L benatit and -~inal cost ot reduc1nqbycatcb and the opti8u8 level or bycatcb.

F1qure 3 rbe aarvinal benefit, aarv1nal coat of reducinq bycatchvith coat effective ..th0d8 (XCI), aarvinal coat orreduC1ft9 bycatch vithout coat effective ..thoda (XC3) ,and the opti8ua level. or bycatcb vith and vithout costeffective ..thoda or reduc1nq bycatcb.

Fiqure 3 Tbe aarqin.l beneCit to the Cishersan ,"Br). aarqinalbenefit to soeiety includinq the Cishersan '"85)..erqinal coat ,"C) oC reducinq byca~ch. and the op~i.umlevels oC byc~~ch. respectively. Cor ~he ~isheraan ~ndtor ,0Cle~v.

14

BYCATCH MORTALITY IMPACTS ANDCONTROL FOR PACIFIC HALIBUT

difficult and has not been achieved withoutsignificant costs in other fisheries. The paperreviews some of the lessons that have emergedfrom this process.Bruce M. leaman, Department of Fisheries

and Oceans, Pacific Biological Station, 3190Hammond Bay Road, Nanaimo BC V9R 5K6,Canada.

JCoastwide bycatch mortality has been reducedfrom approximately 7900 t in 1990 to approxi-mately 6900 t in 1993. Canada will be imple-menting direct bycatch control measures in 1995and has established a target mortality of approxi-mately 490 t in 1997. a reduction of 50% from1991 levels. Data collected from observer pro-grams and directed research studies are produc-ing the information necessary to design andmonitor programs to achieve this result. Thepaper examines some of the economic trade-offswhich must be considered in the design ofbycatch control measures. Finally. the paperexplores the impacts of discard mortality on ourunderstanding of the" population dynamics ofnon-target species.

ABSTRACT

The groundfish trawl fishery off British Colum-bia is characterized by multispecies landingswhich arise through both biological associationsand the fishery management regime. Catches ofmany species may be discarded at sea due tolack of markets, size constraints of existingmarkets, catch prohibition, or quota/trip limitrestrictions. Mortality of the discarded speciesvaries with the fishing method and the biology ofthe species. The fishing gear characteristics, aswell as the exploitation histories and underlyingproductivities of the target species which arecaught together limit the opportunities for jointyield optimization of these target species. Inaddition, incidental mortality on species whichare not targets for the trawl fishery decreasesyield in fisheries for which these species are thetargets. This paper examines some of the econ-omic impacts of bycatch in British Columbiatrawl fisheries from the perspectives of lostyield, management costs, and the impact onknowledge of the population dynamics of non-target species arising from bycatch mortality.The primary focus of this paper is on theimpacts of bycatch mortality of Pacific halibutarising from capture in trawl fisheries.

~., "

."

1...

INTRODucnON

The British Columbia ground fish trawl fisheryshares features with most trawl fisheries in theworld. It is prosecuted with fishing gears thathave limited selectivity and yields multispeciescatches with relatively high proportions ofdiscards at sea. In addition to the voluntarydiscard of fish arising through market forces,discarding can also be mandated by managementprohibition, or arise through the interactionbetween biological associations and the manage-ment framework used to enforce quotas forspecies or species groups. While the quantity offish discarded can often be 50% or higher of thatactually landed, few species management pro-grams in the world provide adequate recognitionand accommodation for this mortality. In thispaper, I examine the magnitude of the discardproblem in the British Columbia trawl fishery, asdetermined through by on-board observations inone the major fishing areas, the myriad causesfor discarding, and the impacts of discardingPacific halibut (Hippoglossus stenolepis) in anon-target fishery on the yield available to atarget fishery for this species. I also present themeasures that have been taken on an interna-tionallevel to control and reduce bycatch mortal-ity of Pacific halibut and illustrate the tradeoffsassociated with some of these control measures.

The management program for Pacific halibut isone of the few management regimes in the worldthat incorporates explicit recognition andaccounting for bycatch mortality. The Interna-tional Pacific Halibut Commission reduces thecatch quota for the directed halibut fishery toaccount for bycatch mortality occurring in trawlfISheries from Alaska to B.C. For 1994, thisreduction totalled over 1100 t and resulted in acatch quota of approximately 4500 t for B.C.waters. Coastwide, the reduction for bycatch wasapproximately 27 % of the final halibut quotasfor Canada and the United States. In 1991,Canada and the United States began a cooper-ative program of bycatch monitoring and controlto reduce the impact of bycatch on the Pacifichalibut resource. Control of bycatch has been

15

Causes of Bycatch and Bycatch Mortality Impacts of Bycatch Mortality

The operational definition of bycatch used in thispaper is that portion of the catch by a given gearthat is, for any reason, unwanted by the har-vester. Bycatch mortality is the mortality gener-ated through this catching process and the subse-quent treatment of the catch. Bycatch is thenfundamentally an issue of the selective propertiesof the fishing gear. If the fishing gear wereperfectly selective for the species and sizesdesired in the market, there would be nobycatch. Such selectivity is exceedingly uncom-mon and is usually restricted to harvestingmethods involving visual identification of targetsprior to harvest. More commonly, fishing gearshows imperfect selectivity, ranging from highlyselective for species or sizes to non-selective.The selectivity may be entirely a function of thegear itself, e.g. mesh or hook sizes, or may berelated to associations of species in the habitat inwhich the gear is deployed.

Assessing the impacts of bycatch mortalityrequires attention to both obvious and obscureprocesses (Table 2). The most direct impact thatfishery biologists should consider regularly is theimpact on population dynamics and yield oftarget species for which there is bycatch mortal-ity of juveniles. However, this mortality compo-nent is seldom considered, even though it isarguably the most obvious impact of bycatch.Stock assessment biologists seldom have infor-mation on the levels of discards for target spe-cies in even the most well documented fisheries.For example, the British Columbia groundfishtrawl fishery is subject to compulsory logbookreporting of catch and effort, on a tow-by-towbasis. Although the logbooks contain provisionfor discard reporting, harvesters seldom providesuch data. Assessment biologists therefore knowlittle about the quantities and species compositionof the discarded catch. Research survey data aresometimes used to estimate the probability ofdiscarding for given size or age groups but thisinformation is generally insufficient for estima-tion of specific time and area impacts.

Bycatch itself is therefore largely a passivefunction of fishing gear and deployment inconjunction with the distribution and biology ofthe species involved in fishing. Conversely,bycatch mortality is a much more complex andactive process. The major contributors tobycatch mortality can be segregated into directand indirect factors. A listing of the majorfactors under these categories (Table 1) findsboth those which are under the control of theindividual harvester and those driven by econ-omic forces quite removed from actions aboardan individual vessel.

Table 2. hnpacts of bycatch mortality and bycatch controlmeasures

Factors affecting bycatch mortality in fisheries.Table

DIRECT IMPACTSLoss of recruits to fished population through juvenile discardsEa>logical impacts rdated to predator-prey and competitive

interactionsEa>nomic impacts through lost or enhanced yields of targetspeciesCosts of enforcement for bycatch controlCosts of monitoring and management

INDIRECT IMPACTSLoss of future yields for species targeted by other fisheries (e.g.

halibut, crab)Extended economic costs concerning undeveloped processing

and marketing potentialEa>logical effects through long-term dynamics of communitiesEffects on dynamics of individual species subject to bycatch

mortalityEffects on the information basis for stock assessment of both tar-

get and non-target species

The magnitude of the bycatch problem in theB.C. trawl fishery is beginning to be docu-mented through observer placement aboardfishing vessels. Observer data gathered in theshallow water fisheries of Hecate Strait during1991-1992 illustrates the general nature ofdiscarding (Table 3). Discards in this fisheryduring the period averaged 56% of the landed

DIRECT FACTORSDepth of captureDuration of fishingSpecies mixture and quantity in catch (e.g., smooth-bodiedvs. spiny)Anatomy and Physiology of the species roncernedSize and age of the individualTemperature and exposure to desiccationHandling practice and time prior to discarding

INDIRECT FACTORSMarket acceptability limits on species and sizes of fishVessels' capability to process catches to meet market specifi-

cations (e.g., freezing)Management prohibition on retention by specific gearsManagement measures which are do not account for the

multispecies nature of catches within fisheries (e.g., indi-vidual species trip limits in multispecies fisheries)

.,j16

J

,,]J

f1':i\.;~

j

~

~

Table 3. s..mwy ~ a.v8d C8-=tI ~ o.c.d8 for h 4 ~., ~ S~ 1~1-1~SUMMER WINTER COMB/NED COMBINED

SPECIES CATCH DISCARD PROP. CATCH DISCARD PROP. CATCH DISCARD PROP.Ika) (ka) .(ta)/ka) /kG) (ta)

~~ ~ ~ 1.00 ~ ~1 o.~ 1~ 1~ 100Big .ua 1613) 1~ 0.87 ~ ~ 1.00 ~25 18415 O:~Black rtIc:kr.h 18 0 0.00 727 0 0.00 245 0 0.008W rtIc:kr.h 0 0 0.00 40 0 0.00 40 0 a.oo8OC8CcG 191 ~ 0.34 2134 0 0.00 2325 65 0.00a.AIw-* 14461 7310 0.51 3m ~ 1.00 14670 7519 0.51CoO -* 124 124 1.00 ~ ~ 1.00 220 ~ 1.00c..y nx:kr.tI 10 47 0.00 417 145 0.35 ~ 192 0.<5CIw. rackr./1 0.00 0 0 0.00 0 0 0.00~ nICkr.h 110 0 0.00 ~ 0 0.00 200 0 0.00~ -* 3) 3) 1.00 58 58 1.00 79 79 1.00o..~o1Ik*;.L.K. rackr./1 ~ 2» o.~ ~ 0 0.00 771 ~ 0.27o..p.. -* 0 0 0.00 131 131 1.00 131 131 1.0000 0-* ~11 N72 0.27 13237 ~ 0.35 49548 14322 0.29Engi8h -* 871~ 58701 o.~ 121945 ~ 0.53 21»143 121~ o.~~ -* 1535 1~ 0.S3 1~ 1~ 1.00 3289 ~ 0.82~ 0.00 55 55 1.00 55 55 1.00~~ 0 0 0.00 ~ --0.00 0 0 0.00~ gr-*IG 0.00 0.00 0 0 0.00~ ~ 145 0.02 21872 115 1).01 31~ ~ 0.01~.ua 11g) 11~ o.~ 1~I9 1~19 1.00 1~ 17959 1.00~ = 135268 1~ o.m 185022 4850 0.00 320288 15427 0.05P8Ciro: t.u 0 0 0.00 15 15 1.00 15 15 1.00P8CifK: h8ibut ~ ~ 1.00 10710 10710 1.00 .7705 47705 1.00P8Ciro: h8TW1g 77 77 1.00 545 545 1.00 622 622 1.00Pacific -~ ~ 310 0.62 1402 0 0.00 1~ 310 0.16PKWI: ~ 1122 1122 1.00 148 148 1.00 1270 1270 1.00P8CifK: ~ 0 0 0.00 78 78 1.00 78 78 1.00P~ -* 1.77 ~ o.c 79J3 1703 0.22 9380 2398 0.26Poact 0 0 0.00 ~ ~ 1.00 236 ~ 1.00PrI7WIish 0 0 0.00 3 3 1.00 3 3 1.00a~~ G 0 0.00 ~ 55 0.11 947 55 0.06R8dbanded roctr.h 417 0 0.00 491 0 0.00 ~ 0 0.00R~ R)Ckr./I 151 1~ 0.72 ~ 543 0.15 38.s 652 0.17Rex -* 1~ 111~ 0.89 19722 15535 0.79 32278 26731 0.S3R~ksole 19:K)57' 92920 0.48 57194 21428 0.37 250251 114348 0.46R~ roctr.h 97 0 0.00 0 0 0.00 97 0 0.00Rougheye R)Ckr./I 64 0 0.00 0 0 0.00 64 0 0.00Sabi8fisII ~I 91S3 0.95 ~1 ~1 1.00 1~2 1~ 0.97s...", 0.00 64 62 0.97 64 62 0.97s.1d sole 13)22 5821 0.48 1~12 1.,89 O.g) ~ 3)110 0.72Sandpaper.ua 10 10 1.00 237 237 1.00 2.7 247 1.00~ 0 0 0.00 111 111 1.00 111 111 1.00Sh8d 0.00 91 V1 1.00 91 91 1.00$/WIer ~ 0 0 0.00 153 153 1.00 153 153 1.00S~ ~ 12~ ~ 0.24 136 136 1.00 1378 ~ 0.32S~y R)Ckr./I 373 0 000 9124 388 0.04 9497 388 0.04Ska18S 31133 31133 1.00 41257 40986 0.99 723SO 72119 1.00Slender sole 0 0 0.00 7 7 1.00 7 7 1.00Speckled sanddab 0 0 0.00 277 727 0.82 277 227 0.82S~ ~ 87734 87734 1.00 43672 43672 1.00 131~ 131406 1.00Spotl8d ratfish 19820 19820 1.00 24910 2.910 1.00 ..730 "730 1.00Starry ~ 8618 8558 099 3987 3987 1.00 12605 ,~ 1.00Starry skala 0 0 0.00 30 3) 1.00 30 3) 1.00SbJrgeon r-t:t- 0 0 0.00 29 29 1.00 29 29 1.00TIgef ~~ 0 0 0.00 trac. ~ 0.00 0 0 000V8m'8CIn rockfish 0 0 000 5 0 0.00 5 0 000""'y. ~k 7639.256 056 2.269 17612 0.73 31SC8 21868 069Wdow~~ !Jace!Jace 0.00 215 10 0.05 215 10 005Wolf... 70 70 1.00 35 35 1.00 105 105 1.00Yelloweye ~kfish 50 0 0.00 279 0 0.00 3:29 0 0.00Yellowmoudt ~~ 0 0 0.00 ISO 0 0.00 ISO 0 0.00Y..~i ~kfish 1253 ~7 077 598 SO om 1651 1017 055

TOTAL I AVERAGE 807548 489119 037 67~ 33759588 058 1~2 826715 056

~~

;~

J

:)."~

L 7

catch, i.e.. for every 1000 t of fish landed, over500 t was discarded. The proportion discardedis higher during summer months, when averagedacross all species, although the proportion of thetotal catch discarded during the winter monthswas higher. Of the species with significantdiscard ratios (Fig. 1). only Pacific halibut mustbe discarded by regulation. All other discardsresult primarily from a lack of markets for thesizes or species obtained. In several instances(e.g. some flatfish spp.) discards could bereduced through gear modifications, such aslarger mesh sizes.

removals relative to available yield for some ofthese stock units (Leaman 1990). The costs ofthis ~proach to the long-term yield from thesestock units is not yet fully understood but maybe substantial. A further cost of aggregation isa comprehensive dockside monitoring programfor all landings from the fishery. This programimposes a shared cost on both industry andgovernment of approximately $700. OOO/y. solelyto provide accurate landing statistics for thismanagement program. The level of discardingat sea to used to circumvent annual quotas andindividual trip limits on these aggregates remainsunknown.

The discussion of bycatch mortality impacts onnon-target species seldom passes beyond thespeculative, due to the paucity of information oneither the quantities of discards or the parentstock from which they were derived. Unlessthese non-target species are themselves theobjects of directed fisheries, insufficient knowl-edge exists to estimate the degree of fishingmortality imposed through bycatch. A notableexception is the Pacific halibut (Hippoglossusslenolepis), which will be treated in the secondportion of this paper.

Where bycatch reduction and control programsare in place. two major impacts of such pro-grams dominate consideration: the cost of moni-toring. managing, and enforcing them; and. theeconomic losses associated with either adherenceto restrictions in target fisheries, or continuedbycatch mortality on non-target species whenrestrictions are not adhered to. These aspectswill also be discussed with respect to the interac-tions of ground fish trawl fisheries and thedirected setline fishery for Pacific halibut.

Figure 1. Catches and discards of groundfish speciesobserved on Canarlign trawlers operating in HecateStrait during 1991-1992.

Perhaps the most insidious effect of bycatchmortality for target species is generated throughdiscarding and misreporting of target species toaccommodate or circumvent managementmeasures for individual species, in mixed-speciesfisheries. For example, there are approximately24 stocks of nine species of rockfishes (genusSebastes) assessed in British Columbia. Thesestock units, which have considerably differentexploitation histories and current productivitylevels, are presently compressed into threecoastWide aggregates for management. Thiscompression is a direct consequence of industrypractices of misreporting and discarding ofspecies to overcome constraints imposed througha previous management regime, which attemptedto manage these stocks individually. The aggre-gation of individual stock yields into coastwideaggregates has led to significant imbalances in

Finally, an impact of bycatch mortality that isless visible but of significant consequence is theimpact on our knowledge base for stock assess-ment. The most benign form of this impactoccurs where there is chronic but stable discard-ing of either target or non-target species. Here,the additional fishing monaIity from discardingwill be transparent to most stock assessments andbe generally subsumed within the estimatednatural mortality rate. More destructive toassessment data sets are instances where bycatchis highly variable within years or in response toincremental management measures. Forexample, under previous management regimes

18for the B.C. trawl fishery the early subscriptionof trip limits for some species would often resultin higher reported landings of species withnormally low levels of incidental occurrence.This scenario suggests high levels of discardingfor species with fully-subscribed quotas, in orderto accrue sufficient landings of these alternativespecies. The alternative of misreported landingsof these alternative species to avoid prosecutionfor illegal landings of the primary species createsequally problematic data. Unreported discardsof minor species also has the impact of removingany opportunity to observe unfished stock: char-acteristics. Productivity of such resources willgenerally tend to be overestimated if observedcharacteristics are mistakenly assumed to repre-sent the unexploited condition.

American states in 1977 (Fig. 3). Coastwide

~

~~j

Figure 2. Regulatory areas of the InternationalPacific Hahout Commission for the west coast ofNorth America.PACIFIC HALIBUT BYCATCH ~

:,~Historical Perspective

""~

~The Pacific halibut is the object of a majordirected fishery off the west coast of NorthAmerica. extending from the Bering Sea toOregon. This lucrative fishery yielded over 59Mlb in 1994. worth over $200M (U.S.) to har-vesters (IPHC 1994). Pacific halibut have acomplex reproductive biology involving spawn-ing migration of adults and consequent counter-migration of juveniles. Although smalleramounts of spawning occur throughout the coast.the majority of halibut spawners migrate towardthe central Gulf of Alaska (Fig. 2, Areas 3A/B)in the winter months. Eggs and larvae drift withprevailing westerly currents to the western Gulfand eastern Bering Sea. Juveniles begin migrat-ing back in an easterly and southerly directionbeginning at about age 2 y and are interceptedby target fisheries for other species between ages.2-7 y. The primary fisheries of interception aretr.awl (both groundfish and shrimp) and hook andline fisheries in the Bering Sea (Area 4). Gulf ofAlaska (Areas 2C-3A), trawl fisheries off BritishColumbia (Area 2B), and trawl fisheries offWashington and Oregon (Area 2A).

!.f.

~: t

..

j

bycatch increased after 1985 as the U.S...Americanized" the fisheries of the Bering Seaand Gulf of Alaska. U.S. factory trawlersfishing for pollock, flatfish and Pacific cod werethe source of most of this increase. Estimatedbycatch mortality in Area 2B (B.C.) during thesame period was relatively stable (Fig. 3), andwas generally below 2 Mlb. The bycatch ofhalibut in B.C. is highest in Hecate Strait,followed by Vancouver Is. and Queen CharlotteSound, with fisheries for shallow water soles andPacific cod accounting for the majority ofbycatch mortality.

Halibut Bycatch MortalityTotaJ Stock Ys. Area 2B

~~~

"j

'.:~

illHistorically. bycatch monaJity of Pacific halibutoccurred primarily in fisheries conducted byforeign distant-water trawlers operating inAlaskan waters. Bycatch mortality rose to over20 Mlb in the mid-1960s but was reduced toapproximately 7 Mlb following the promulgationof extended fisheries jurisdiction by North

jFigure 3. Bycatch mortl1ity of Pacific halibut for

Brirlsh Columbia waters (Area 2B) and the entirewest coast of North America. 1962-1993.

,:;j

1:(

:;ii

19

Bycatch is a joint function of fishing effort, theabundance of the target species, and the abun-dance of the non-target or bycaught species.The influence of halibut juvenile abundance onbyca~h can be inferred from data relatiJlg abun-dance of juvenile halibut in the Bering Sea,estimated through systematic research trawlsurveys, to bycatch of halibut in groundfishfisheries (Fig. 4). The declining bycatch ofhalibut following extended jurisdiction, althoughclearly related to a number of area closures andbycatch restrictions imposed on foreign vessels,also occurred during a period of declining abun-dance of juvenile halibut. Conversely, theincreasing bycatch after the Americanization ofthe Alaskan fisheries was coinciden,t withincreasing abundance of halibut juveniles in theBering Sea.

attempts to compensate the stock for bycatchmortality through reductions in directed fisheryquotas to replace the potential egg productionlost through bycatch. Compensation is calcu-lated on a coastwide pool basis because of theobserved spawning behaviour but assigned toeach management area in proportion to thedistribution of adult biomass. Compensationthus accounts for the movement of juveniles outof the areas of bycatch occurrence. However.this has the novel effect of dissociating some ofthe areas where bycatch originates (primarily theBering Sea) from the penalties in lost yield thatare paid (Gulf of Alaska and further south).Table 5 shows the relation of bycatch source andthese yield reduction penalties among manage-ment areas.

Table 4. Losses due 10 bycalch mortality of Pacific halibut.

Juvenile Abundance (Year i-I)vs. Bycatch (Year t)

RECRUITMENT LOSSNo adjustment to compensate forAverage loss in adult equivalent weight is 1.2 times weight of

bycatch

LOST REPRODUCTIVE POTENTIALIPHC adjusts sctlinc yield to attempt to compensate the stockLost recruitment (1.2) times the ratio of adult equivalent

biomass to recruitment biomass (0.83) is used to replace eggproduttioo lost through bycatch

The resulting 1.0 is the adult equivalent biomass subtracted fromthe sctIinc quota for each lb of bycatch (adult reproductivecompensation)

TOT AL ~ YIELDAduh reproductive compensation (1.0), of which 0.6 wil1

cvcntually be caught in subsequent years in the fishery ->0.4

+ Lost recruitmc:nt biomass = 1.2 times bycatchResults in .total yield loss of 1.6 lb/lb of bycatch

1975 1877 1878 1~1 1883 Ig85 1887 Ig8g

Year (t)

The measures adopted by the IPHC for bycatchcompensation result in substantial penalties paidby B.C. halibut fishers for bycatch mortalityoccurring in Alaska. For example. in 1995 thetotal quota reduction of halibut extracted tocompensate the stock for bycatch mortality willbe approximately 16.0 Mlb. to which bycatchmortality in B.C. contributed 1.3 Mlb. How-ever. B.C. fishers will pay a total of3.05 Mlb inquota reduction penalties. of which 2.8 Mlbaccrues to B.C. solely due to bycatch in U.S.waters. While the system used by the IPHC alsoresults in direct penalties to U.S. halibut fishersfor Canadian bycatch. the balance is stronglyagainst Canada. This imbalance. coupled withthe increasing trend in U.S. bycatch in the late

Figure 4. Relationship of the bycatch of halibutjuveniles in the Bering Sea and the abundance ofhalibut juveniles estimated by ttawl surveys in theprevious year, 1975-1991.

Compensation Measures

The Pacific halibut resource is managed jointlyby the U.s. and Canada through the InternationalPacific Halibut Commission (IPHC). The IPHCis one of the few management agencies in theworld that attempts to deal explicitly with theeffects of bycatch mortality on the exploitablestock. The IPHC has developed estimates oflosses to the halibut stock due to lost recruit-ment, lost reproductive potential. and total lostyield (Table 4). At present, the Commission

20

1.0 Mlb by 1997.1980s. triggered a landmark agreement to con-trol and reduce bycatch mortality between thetwo countries in 1991. Measures Used to Monitor and Control Halibut

Bycatch

The most significant feature of bycatch reductionprograms is the development of a process toestimate bycatch and monitor changes resultingfrom various reduction measures implemented.The U.S. began a comprehensive program ofmonitoring in the early 1990s which is nowfunded directly by harvesters. This programinvolves 100% observer coverage for vessels> 125' in length and graduated observer cover-age for smaller vessels. The program cost isvariable but is generally in the $15-20 M range.This program is designed to estimate bycatchthrough direct observation. Canada has alsoimplemented an observer program, although it isnot user-funded. It is designed to. estimateaccurately the ratios of halibut bycatch to targetspecies catches for the purpose of extrapolationto total bycatch.

Table S. Example of apponioamcDt of caIcb limit redlaclioas by \he IPHC (reprl)duaj"eCOaIpeasalioa) by reIIIlaIOry area for ea:ecu of bycatcll monaIily ill 1992. - '

~:;"".14 IToc8iArea I~~ 1= 12A 128 2C 13-'

U

~1.60

'G:70

~ 9

49.30

61.14

136.61m

"1.;J

'1

~:fj5.3 I Q.QS I. o.n .I 1m I 2.41 0.371 0..511 5.31~1

0.481_0.651LOS I Lol 14~~

~I6.11 ~I LIZ I 1.401_~1431 0.131 2.451 3.ml 6.71

W

3B 2L12

4 2U3

Toral 300.36

The 1991 IPHC Bycatch Reduction Agreement:j

Canada and the United States, through theIPHC. agreed in 1991 to embark on a process ofhalibut bycatch mortality control and reduction.A Halibut Bycatch Work Group (HBWG) wascreated by resolution of the Commission andproduced a series of recommendations, that wereadopted by the Commission in July 1991(Salveson et al. 1992). The HBWG conductedan extensive investigation of the bycatch issue,reviewed existing measures for bycatch control,and detailed a number of mechanisms that couldbe implemented to reduce bycatch mortality.The group identified the low levels of bycatchmortality achieved in the mid-1980s as a desir-able goal for reduction. Notably. the group alsoidentified that increasing the survival of thosefish which were caught and discarded wouldlikely be as. or more. effective than decreasingth~ number of fish actually caught in non-targetfish~ries. This recognition provided support foralternative measures of bycatch mortality reduc-tion to traditional measures involving only timeand area prohibitions. .

A variety of measures to control and reducebycatch monality in the two countries have beenimplemented since the 1991 agreement. Theseinclude: bycatch caps or limits for areas andfisheries; time/area closures; bycatch perform-ance standards for specific fishing gears; sea-sonal apportionment programs for bycatch capsto prolong fishing seasons; fishing gear modifi-cations to reduce encounters of halibut; carefulrelease programs involving grid sorting andmanipulation of fish on hook gear; and, vesselincentive programs designed to reward fishing tolower bycatch levels. through access to addi-tional target species' quotas.

:~,i

The implementation of these measures has notbeen without controversy. They involve directcontrol of valuable ground fish fisheries and.panicularly during the initial years of implemen-tation, direct penalties in terms of forgonegroundfish yield due to fishery closures asbycatch caps were reached. For example, in1992 fishery closures associated with bycatchcontrol resulted in forgone groundfish harvestsof over 174.000 t in Alaskan waters. This econ-omic cost to the groundfish industry representsa substantial proponion of the total wonh of thehalibut fishery. This comparison has fuelledintense debate on the merits of protecting ahalibut fishery within the U.S. management

The 1991 agreement identified a process, atimetable and a target. In panicular, the UnitedStates agreed to bring all fisheries under bycatchlimits for 1992 and to implement a program toreduce bycatch limits by a minimum of 10%/yb~ginning in 1993. Canada has subsequentlycommitted to bring its bycatch mortality down to

,:.:Ii

21

system. It is some tribute to th~ resolve of bothcountries that adherence to the principles of the1991 agreement has been maintained. Therecognition that groundfish catches similar tothose at present were harvest by foreign fleets inthe mid-1980s with much lower halibut bycatch,has helped to support this resolve. Canada has ,explored similar approaches to fishery closuresand the flavour of the economic tradeoffsinvolved can be seen in Table 6.

15.996 Mlb, in spite of a reduction in Canadianbycatch mortality from 1.661 to 1.305 Mlb overthe same period. The lack of adherence to U.S.mortality caps resulted largely from difficultiesin projecting closure dates for trawl fisheries dueto large variability in fleet composition, andhigher than estimated incidence rates in rock soleand turbot fisheries.

Future progress on bycatch reduction is some-what uncertain, although both countries have re-affirmed their commitment to the 1991 agree-ment. There are presently no measures toreduce bycatch mortality caps in Alaskan watersbefore U.S. management agencies. Canadaremains committed to achieving a 1.0 Mlbbycatch mortality limit by 1997 and has imple-mented a mortality cap in Hecate Strait for 1995.This will be followed by additional caps for thewest coast of Vancouver Island and QueenCharlotte Sound as required in 1996 and 1997.

Table 6. ~mic tradcoffs ~d wilb ~tcoda1 dO5IIrcs of uawI wherics off thewest CO&SI of VaDCOU..cr Island.

VANOOUVEllISLAND TRAWL FISHERY(Based aD 1976-1990 1IIOGIbIy.-ap)

Lessons from the Halibut Bycatch ReductionProgram

A number of important lessons have emergedfrom the joint efforts of the United States andCanada to reduce halibut bycatch mortality.Perhaps the single most important lesson is thata recognition of the need for change must beestablished in the minds of regulators. If man-agement agencies do not share user groups'perceptions of the need to reduce bycatch.implementation of programs will be delayed orfrustrated at every potential occasion.

There have also been significant costs to theimplementation of bycatch reduction that werenot recognized explicitly at the beginning of theprogram. Aside from observer programs costingmillions of dollars, catch monitoring progx"ams,enforcement and prosecution, and the researchrequired to evaluate reduction measures (e.g.physiology research and tagging progranlS toestimate viability of discarded fish) have resultedin substantial costs in the program of byc:atchreduction.

Another important lesson is that we cannot haveeverything. That is, achievement of the goal ofbycatch reduction requires recognition thatbycatch mortality cannot be reduced to zerowithout elimination of some other fisheries. Itwill clearly be unacceptable to eliminateground fish fisheries solely to eliminate bycatchmortality for halibut. Participants in all fisheriesmust be willing to accommodate the needs ofother sectors if progress is to be made. How-ever, participants must also acknowledge thathalibut bycatch is presently higher than it needsto be in order to harvest the full groundfishquotas. Decisions on bycatch control measuresinvolve millions of dollars worth of halibut andground fish harvests, and proponents of particularmeasures can be expected to be well-funded andpersistent in supporting measures they favour.

Progress on Bycatch Reduction

Coastwide halibut bycatch mortality declinedfrom a high of 18.101 Mlb in 1990 to 15.189Mlb in 1993. Some of this decline resulted fromchanges to our estimates of discard mortalityrates for bycaught fish, and the remainder fromlower actual catches of halibut. Discard mortal-ity was reduced through modified fishing prac-tices and improved estimation of halibut condi-tion resulting from observer data. However, in1994 coastwide bycatch mortality again rose, to

""122

This persistence will translate into prolongedlobbying of management agencies for desiredresults. Efforts to effect change will thereforebe most effective if they are pursued within ajoint optimization framework for target and non-target species.

LITERATURE CITED

]International Pacific Halibut Commission. 1995.Report of assessment and research activities,1994. Int. Pac. Hal. Comm. Seattle, WA.274p.

Leaman, B. M. 1990. Slope rockfish. pp. 195-258 In Tyler, A. V. and J. Fargo (eds.)Groundfish stock assessments for the westcoast of Canada in 1989 and recommendedyield options for 1990. Can. Tech. Rep.Fish. Aquat. Sci. 1732:343p.

The infonnation that is necessary to evaluatealternative measures is highly detailed andanalyses may be complex. Collection and analy-ses of these data will be correspondingly expens-ive and user groups can expect to bear some orall of the costs for these programs. Thesc~"hidden" costs to implementation of bycatchcontrol, and the need to generate the regulato~'authority to recover these costs, have been .1significant component of the difficulty in reduc--ing bycatch mortality.

1

Salveson, S., B. M. Leaman, L-L. Low, and J.C. Rice. 1992. Report of the halibutbycatch working group. Int. Pac. HalibutComm. Tech. Rpt. 25:29p.

,j

Finally, the efforts to reduce bycatch mortalityhave been extremely slow in large measurebecause it has been difficult to implement reduc-tion measures that incorporate individual respon-sibility for bycatches. Most of the measures thathave been implemented have been applied at thelevel of entire fleets or gear sectors. Many ofthese measures have foundered on the reality thatfleets do not act in the best interests of individ-uals. The absence of mechanisms to effectcontrol and reduction measures, and moreimportantly to provide incentives, at the individ-ual vessel level was an important element in theslow progress achieved in the initial stages of thehalibut bycatch control program. Regulatorshave now recognized that embedding individualresponsibility in such programs is often the mostimportant prerequisite to success.

'~,~

~;;;.

~

;,i

~,;j

ACKNOWLEDGEMENTS

JI am grateful to Jeff Fargo for provision ofinfonnation from observer trips on British Col-umbia trawlers and for comments on the presen-tation. I also thank staff of the InternationalPacific Halibut Commission for assistance in thepreparation of some estimates of reproductivecompensation measures used by the Commission.

j

'.j:~

~;4

,~,~.i1i

23

THE IMPLICATIONS OF VOlUN'"ARYAND REGULATORY SOLUTIONS TOBYCATCH AND DISCARD IN THE ROCKSOLE FISHERY

race and the potential for rights to flow to har-vesters who fish with the lowest bycatch. Inaddition, the ITQ proposes gradual reductions inITQs for bycatch species when ITQ shares aretrans ferred .

John R. Gauvin & Joseph R. Blum,American Factory Trawler AssociatioD, 4039 -21st Avenue West, Suite 400, Seattle,Washington 98199, USA

...

Bycatch and discard will likely be the primaryfocus for fisheries management for the remainderof this decade. Of great concern, from theperspective of the fishing industry, is that theissue of bycatch and discard is being oversim-plified and the facts are being misrepresented ina wholesale manner. For one, due to erroneousstatements and the lack of a thorough andunbiased treatment of the issue, bycatch anddiscard are generally construed to be related toor associated with overfishing. As a conse-quence, for the average person who followsenvironmental concerns, a thematic link existsbetween bycatch, discard, and overfishing.There are, however, significant departures fromthis convenient rule of thumb of "they're wipingit out and they're wasting it all" that certainenvironmental groups contend.

ABSTRACT

Approximately 65% of the catch by weight inthe Bering Sea and Aleutian Islands (BSAI)rocksole fishery was discarded last year.Rocksole is targeted for its roe although the fleshof large rocks ole is utilized. Discard is motivatedby the fact that small rocks ole lack roe andcommand very low prices. Production costs forsmall rocksole would exceed revenues even forthe most efficient trawlers.

The rocksole stock and stocks of bycatch speciesare all believed to be healthy according to stockassessments. The allowable biological catch(ABC) for rocks ole was 313.000 mt in 1993. butthe total allowable catch (TAC) was set at75.000 because of a two million mt eco;systemremoval cap. Only 60% of the rocksol(: TACwas taken in 1993 because the bycatch allowancefor Pacific halibut was taken before the T ACwas met. Thus the bycatch/discard problem inthis fishery is not overfishing of rocks ole orbycatch species. but a perceived resource wasteissue.

One very large departure to this rule of thumb isin the largest fisheries in the United States, thefisheries of the North Pacific: the Gulf of Alaskaand the Eastern Bering Sea. Biological assess-ments of the fishery resources in the NorthPacific confirm that overflshing is not occurringfor most species. Yet in Bering Sea and Gulf ofAlaska fisheries, bycatch and discard in terms oftonnage are relatively high, by virtue of themagnitude of the fisheries in the region. Tocomplicate matters, data from an independentfishery observer program in the North Pacificshow that bycatch rates per ton produced aregeneraIly low compared to other United Statesfisheries or fisheries around the world (NRC,1994). This serves to muddy what some envi-ronmentalists want the public to believe. In fact,the more the public learns about the fisheries ofthe North Pacific, the more complicated theissues and tradeoffs are likely become.

This presentation will discuss resource waste andmandated full utilization which would reduceefficiency and bring about economic losses.Three proposed bycatch/discard solutions will beoutlined as they relate to the rocks ole fishery.The fIrst is an industry proposal to increasemesh size. The second proposal, called "HarvestPriority", is billed as a reward program. Itwould take away fishing time from vc~sselswhose bycatch rates exceed an industry-proposedstandard by gear and area. Fishing would still beconducted in a common property race for fish.The final proposed solution is an individualtransferable quota system (ITQ) with tradablerights to bycatch species. The bycatch/di:5cardreduction mechanism of the ITQ is expected toresult from elimination c;>f the common property

Why focus on the Rock Sole Fishery?

As attention has been focussed on what advocacygroups are calling "waste" in the North Pacific,the fishery for rock sole (Pleuronectes

24

bilineatus} in the Bering Sea/Aleutian Islands(BSI AI) has received a great deal of scrutiny.One reason is that in 1993, approximately 65%of the groundfish brought on board in the fisherywas discarded. This is the highest discard ratefor a trawl fishery in the North Pacific. In fact,it is four times higher than the average discardrate for trawl fisheries in the Bering Sea in 1993(pacific Associates, 1994).

flesh of the rock sole is consumed separatelyafter the roe is removed. .

Approximately 25 vessels targeted roe rock solein 1994. All of these vessels were trawlcatcher/processors and most of these boats wereat-sea processors that head, eviscerate, andfreeze product on board. Vessel lengths typical-ly range from 140 to 250 feet, which is con-siderably smaller than catcher/processors withmore sophisticated processing capability. JThis paper focuses on rock sole because it is a

North Pacific fishery where bycatch is large illabsolute terms as well as in terms of a rate peJ~ton. The rock sole fishery is exceptional for tht:North Pacific because. in some ways. it does fitthe mold of what environmentalists contend isoccurring in the North Pacific. On the otherhand. the link between overfishing and bycatchespoused by the environmental group does not fitthe rock sole fishery and really fits none of theNorth Pacific fisheries at all. Through thisdiscussion of the rock sole fishery. it is hopedthat the reader's appreciation for the complexityof the bycatch/discard issue. its causes. and thetradeoffs involved with potential "solutions" willbe enriched.

To understand the fishery, it must first be recog-nized that rock sole are targeted principallyduring a four to six week period from January20 to the beginning of March. During that time,the fishery is an Olympic style fishery whereinfishermen compete for rock sole before theprohibited species bycatch caps (PSCs) forhalibut or red king crab are exhausted or- theprime roe period is over, the former being morelikely to occur before the latter. The totalallowable catch limit for rock sole does not drivethe race for fish in the fishery because prohibitedspecies caps and other management regulationsgenerally mean that the rock sole fishery isclosed long before the total allowable catch limitis met.

]'1

jj

The Rock Sole Fishery

Female rock sole with the highest recovery rateof roe receive the highest prices and femaleswithout roe and male rock sole command rela-tively low prices. Even during the peak of theroe rock sole period, catches include rock solewithout roe, Pacific cod, pollock, and flatfishother than rock sole (flathead sole, rex sole,yellowfin sole, Alaska plaice etc.). In addition,considerable quantities of other species that aregenerally considered to have no or very lowcommercial value such as skates, rays, demersalsharks, and arrowtooth flounder are taken.

Although rock sole is a relatively insignificantfisbery in the BSI AI management area in termsof tonnage. comprising only 5 % of the overallBS/AI trawl catch in 1993. the 65% discard ratein the fishery does bring the fishery to theforefront in terms of potential regulatory fixes tothe bycatch/discard issue. In contrast, themid water pollock (Theragra chalgogramma)trawl fishery in the Eastern Bering Seaaccounted for 1.3 million metric tons in 1993(67% of overall BS/AI landings). and only49.000 metric tons of this have been discarded (adiscard rate of four percent).

~

J

~

:?i.'iWith the race for rock sole before the king crabor halibut prohibited species catch limits aremet, fishermen generally process only thehighest-valued species which can mean only roerock sole or roe rock sole and Pacific cod andsome large flatfish other than rock sole.Although distasteful to some, this is economical-ly rational behavior because to fill freezer spacewith species other than roe rock sole couldmean that the vessel would have to offloadprocessed product earlier and might not be able

The rock sole fishery produced approximately22,400 metric tons of retained landings of rocksole in 1993, worth approximately $34 milliondollars at the first wholesale level. Roe rocksole was the principle component of revenuefrom the fishery. Roe rock sole are typicallyfrozen whole or headed and eviscerated with theroe left in the body cavity. Roe is removedfrom fish when secondary processing occurs.Most roe rock sole is exponed to Japan. The

25

In July of 1994, industry requested that theNorth Pacific Fishery Management Council(NPFMC) develop regulations to require a sixinch square mesh panel in the top portion of netcodends. According to an industry survey, mostrock sole fishing currently occurs with codendmesh openings of four to five inches andcodends are mostly double-walled. Double-walled codends further restrict the size of netmesh openings.

to return to the fishing grounds before the seasonwas over. Even if freezer space were not criti-cal in tenDS of having to offload and thus forfeit-ing a second roe rock sole trip, retaining theseother species would result in lost fishing timeduring the window of time when the fishery isopen and rock sole roe recovery and quality ishigh.

Another mitigating factor in the dec:ision toretain or discard Pacific cod and other round fishspecies with commercial value is that round fishare frequently in less-than-optimal conditionwhen captured in conjunction with flatfish. Thisis due to the abusiveness of flatfish skin.

If larger mesh serves to avoid catches that willlater be discarded, then it is logical to ask whythe fishing industry would not have alreadyincreased the size of the mesh voluntarily. Theanswer is that an unfortunate side effect ofexisting regulations designed to control bycatchunder the Vessel Incentive Program (VIP) setstandards of prohibited species (PSCs) catchrates in terms of percentages of .total weightcaught. This means, for instance, that thehalibut VIP rate which could trigger a violationis based on the number of halibut per ton oftotal catch, not retained catch. Assuming thesame number of halibut per tow, a fishingoperation that excluded catches of small fish byusing larger mesh could be in violation becausethe actual halibut rate might exceed the VIPstandard rate. Had the larger mesh cod end notbeen used, the same tow might not have been inviolation. Under this regulatory regime, smallrock sole and other fish thus serve as ballast andany change in mesh would have to be accom-panied by a change in VIP standard rate.

What drives the impetus to discard non-roe rocksole and other species in the rock sole fishery isthe derby nature of the fishery and tlle sheermagnitude of price differentials for the species inthe flatfish complex that are taken while target-ing rock sole (Table 1). Prices for non-roe rocksole can be as little as one-third to one-fourththat of roe rock sole and Pacific cod is generallyless than half the price of roe rock sole:.

Rock Sole Industry Initiatives to Decrease Dis-card in the Fishery

Table 1: Wholesale prices for species landf:d in dierock sole fishery. FOB Dutch harbor

In December of 1994, the North Pacific FisheryManagement Council approved the increase inmesh size for the rock sole fishery but thischange, assuming prompt consideration andapproval by the Secretary of Commerce, cannotbe in place for the upcoming fishery in thewinter/spring of 1995. In spite of this, manymembers of the rock sole fishery appear willingto increase mesh size to six inches throughouttheir codends without a regulation in place andlacking a change in the VIP standard rate. Thiscould result is a dramatic increase in VIP viol-ations if cases are prosecuted. Some in theindustry see the move to larger mesh nets as theone of the few available avenues for the fisheryto reduce its discards and therefore improve itspublic image given the current regulatoryregime.

S~ies ~roe rock sole 1.05rock sole (S-L) 0.40Pacific cod (H +G) 0.55pollock (H +G #2) 0.25Alaska plaice 0.25flathead sole 0.45yellowfin sole 0.25

(average wholesale prices from industry data)

Mesh Size

A potential means of increasing the retentionpercentage in the fishery is to increase codendmesh size so that at least more of the small rocksole and other groundfish escape through the netwebbing. Some of these fish would presumablysurvive. If increased net mesh works to allowunwanted fish to escape, this would make thepercentage of roe rock sole in the catch greater.

26

assumptions, gross revenue would decrease by$16,500 per trip. Assuming there are 25 vesselsfishing next year and that each vessel make twoor three trips during the roe season, the loss ofgross revenue that can be expected from theindustry initiative is approximately $825,000 to$1.23 million for the rock sole roe season.

Proposed Industry Initiative to Increase Retention

Another means of increasing retention in thefishery is to retain more of the catch that iscurrently being discarded. This could be doneon a voluntary basis to respond to public criti-cism of "waste" in the rock sole fishery. InSeptember of 1994. rock sole fishermen agreedupon an industry-wide rock sole initiative toincrease retention in the fishery by thirty percentin 1995. Several rock sole participants havt:stated that thirty percent is probably the maxi..mum increase in retention that is possible in the:short run given the economic conditions facingthe industry and the expectation of continuedopen-access management.

IProportionally larger decreases in gross revenuecould be expected for every unit increase inpercentage retention beyond 46 % that the indus-try has proposed. This is because fishing oper-ations will first select the fish that have the valueclosest to that of roe rock sole. If cod are themost likely to be retained, then the cod with thehighest value will be retained first. Next coddamaged by contact with flatfish would be acandidate, or other flatfish species that commandrelatively high prices to minimize the loss ofrevenue to the vessel. If the retention percen-tage were significantly increased, then smallrock sole without roe will have to be retainedand effects this would have on revenue losseswould be very significant.

~

Lack of defined individual allocations under openaccess continues the race for fish which createsthe incentives to fish as fast as possible. Thismeans that fish of lesser value cannot be pro-cessed economically because the fishery is drivento process as much of the high-value productbefore one of the PSC caps is met and thefishery closes. Some of the economic effects ofthis proposal to increase retention under theOlympic fishery are evaluated below.

The impacts of increasing retention would haveon the rock sole fleet should not be viewed in avacuum because many vessels are at or justabove the break even point at this time. Toappreciate the effects of such a decrease in grossrevenue, one has to understand thatcatcher/processors typically fish in high volume,low profit margin fisheries. Vessels work ontight profit margins because fishing in the BeringSea involves high fishing costs due to theremoteness of operations, large travel distancesto offload points, fishing conditions that areharsh and expensive, and what can be describedas high variable cost structures of at-sea pro-cessing operations in general.

Seen on a per trip basis, increasing retention bythirty percent would have large effects on theexvessel trip revenue and possibly make thefishing unprofitable for marginal participants.Assuming that a typical vessel has a freezercapacity of 300,000 pounds of processed prod-uct, the goal of increasing retention by 30%would mean that a vessel would, on average,have to increase its retention percentage from35 % to 46 % , an net increase in retention of11 %.. If a vessel retained only roe rock solebefore, on a 300,000 trip approximately 33,000pounds of non-roe rock sole would have to beprocessed and retained.

~

::;~~

I~JM

The Potential Benefits of Increased Retention inthe Rock Sole Fishery

On a first wholesale basis ("freight on board"(FOB) Dutch Harbor), if a firm decided toretain Pacific cod, a logical choice given itsprice relative to other candidates, then the grossrevenue loss of approximately SO.50 per poundwould occur for every pound of processed codretained. This is based on an average firstwholesale (headed and gutted) cod price of $0.55and an average roe rock sole price of $1.05 forfrozen (round, ungraded) product. Under these

The potential benefits of decreasing bycatchand discard can be evaluated in terms ofresource conservation, ecosystem effects, con-sumer benefits, and improvement in publicperception. In theory, these benefits could berealized if the percent retained in the fishery isincreased or fishing methods are better able totarget roe rock sole so that bycatches do notoccur.

3::

,j

27

percentage that is a fraction of the measurementerror in the assessment of stock biomass (seeNPFMC, 1992).

Pollock and cod are the principle round fishbycaught in the rock sole fishery. A largeincrease in biomass has occurred for Pacific codin recent years and the status of the pollockstock is thought to bt; excellent (U5DOC, 1994).Fishing mortality on cod and pollock that resultsfrom the rock sole fishery is only a small per-centage of overall mortality on these species. Asis the case for all fishery management in theNorth Pacific, the mortality from the rock solefishery is accounted for when allowable biologi-cal catch (ABC) and total allowable catch (f AC)limits are set for these species. 50 there is littlein the way of a biological evidence that fishstocks bycaught in the rock sole fishery wouldbe in better health if bycatch were reduced oreliminated in the rock sole fishery.

Although expectations for these types of benefitsare reasonable, in the particular case of the rocksole fishery, and other North Pacific fisherieswhere exploitation rates are very low, whetherthere are biological benefits from decreasingbycatch and discard is debatable. Thert: may beecosystem effects but whether these would bepositive or negative depends on how criteria aredefmed and whether exploitation rates thatcurrently occur from the rock sole fishery sig-nificantly impact fish stocks at all.Overall, the main benefit of increased retentionor improved targeting of roe rock sole is likelyto be improved public image for the rock solefishery. This is because fishing mortalitiesoverall on rock sole and the other speciesbycaught in the fishery are extremely low andthere are probably no tangible stock conservationbenefits to improving the ability to target femalerock sole from male rock sole or other ml~mbersof the flatfish and round fish species complex.The effective annual exploitation rate on die rocksole population is less than four percent and thepopulation has been growing steadily over thelast decade (Figures 1 +2). The same is true forother flatfish that comprise most of the bycatchin the fishery such as flathead sole, yellowfinsole, rex sole, and Alaska plaice according tostock assessments (USDOC, 1994). Thebiomass increase in recent years for rock sole isslightly more dramatic than has occurred foryellowfin sole and other flatfish species that arecommonly bycaught in the rock sole fisher:y, butoverall, the biomass of flatfish is thought to beincreasing to historically high levels (USDOC,1994). Exploitation rates for other flatfish aregenerally similar or lower than that for rock sole(USDOC, 1994).

Decreasing catches of prohibited species such asred king crab and halibut affect the amount oftarget catch that can be produced in the roc}: solefishery but probably have no tangible effect oncrab and halibut stocks. This is because halibutand crab PSC caps are very low in tenDS of thepercentage of the biomass that the cap com-prises. For red king crab, for instance, the redking crab PSC limit for the rock sole fisheryrepresents less than one-fourth of one percent ofthe red king crab population (population size asof 1994). Fluctuation in crab stocks affects thispercentage but caps are designed to be a smallfraction of the biomass, and in essence, and

One could argue that consumers forfeit theavailable source of edible protein when bycatchis discarded and hence not brought to the con-sumer. This argument, however, must firstrecognize that only a portion of these bycatchesare on adult fish of market size, i.e. of a sizethat consumers would be willing to eat. Wherebycatch is of juveniles of commercially import-ant species, the impact on consumers, the fishingindustry, and value from the nation's naturalresources as a whole must be evaluated as thediscounted future revenues from those fish, andafter the effects of natural mortality areaccounted for. This is particularly true when theresource is healthy, as is the case for the bycatchspecies in the rock sole fishery because futurestock conditions are not jeopardized by removalsas bycatch or as directed fishing. In the NorthPacific, allowable fishing levels take into accountboth directed fishing and bycatch.Another consideration in assessing the value offish taken as bycatch versus taken by directedfishing is that, just like mandating high levels. ofretention, avoiding bycatch is not without coststo the efficiency of fishing operations. Analyti-cally, the cost of avoiding bycatch must becompared to the net future benefits (i.e. dis-counted at some relevant discount rate) fromjuvenile fish to understand the tradeoffs fully.This cost benefit comparison would also involvethe effects of natural mortality on the future

28

benefit of juvenile fish over the interim period.When overall fishing mortality is low and stocksare increasing, removals of juvenile fishbycaught in the rock sole fishery may have littlemeasurable effect on stock conditions. Yetavoiding capturing those juvenile fish is expens..ive. If this were not the case, then the fishingoperation would have done so in the first place.When unwanted catches occur, fishing operationsincur the cost of sorting and discarding whichinvolves time and labor costs.

maximize profits. Profits are taxable and exportearnings are recirculated through the domesticeconomy.

Concluding Thoughts

When evaluating the effects of regulations orinitiatives that require increased utilization of thecatch, another consideration is that in manycases, it would cost more to the fishing operationto produce something out of these catches thanthe catches themselves could be sold for. Thiswould likely be the case for skates, rays, sharks,or cod and pollock that are damaged becausethey are brought up in the codend with flatfish.In this case, operating losses from mandatingutilization of non-economic species and damagedfish would have to be passed on to the productsthat are produced, i.e. higher prices and poten-tial losses of consumer benefit.

For adult cod and pollock that are not damaged,and for the flatfish species for which marketsexist but price differentials tend to motivatediscard rather than retention in the rock solefishery, fishing operations may be able to pro-cess and retain these catches without incurringdeadweight losses. The loss in this case is theopportunity cost of sacrificed rock sole with roeearnings compared to lower earnings throughretention and processing of lower-valued species.Devoting limited hold space to other specieswhen the roe season lasts approximately sixweeks could impose large profit losses for someoperations. From the perspective of economics,regulations that require increased retention aremandate reduced profits are difficult to justifywhere measurable biological benefits are notcreated, or those biological benefits created are

negligible.

Fishing companies that participate in the rocksole fishery have volunteered to increase reten-tion by 30% for the coming season. This maynot satisfy public perceptions but, according tothe industry, this is a considerable first stepconsidering the inherent tradeoffs and the econ-omic health of the industry. An importantconsideration is that lack a concrete model tosystematically compare economic losses tobenefits of increased retention in the fishery. Adefined objective that clarifies why bycatch anddiscard are a consideration when fishing exploi-tation rates are so low is also .lacking. Acareful, stepwise approach is probably warrantedunder these circumstances, rather than an emo-tional approach that seeks to "solve" the problemin a very short period of time. For instance, ameasured approach might evaluate availableevidence of economic performance in the fisheryas retention standards or bycatch restrictions aregradually increased.A reasonable schedule of increases in retentionknown to industry participants in advance couldfacilitate this transition by allowing the gradualdevelopment of markets for lower-value speciesor allowing participants with a less ability toprocess and market low margin species to findother fishing or business opportunities. Such ameasured approach would at least minimizeeconomic disruptions should policy makersconclude that retention is a more importantobjective than economic performance, employ-ment, export earnings, and other economicfactors.

A potential long run solution that would increasethe ability to utilize low-valued species under anincreased retention standard is to slow the racefor fish that currently occurs in the roe rock solefishery. Some critics contend that mandatingretention will already slow the fishery down, butthat approach does so at a maximum cost toeconomic efficiency. A more reasonableapproach would be to break the incentives torace for fish by allocating individual fishingallotments of prohibited species catches forhalibut and crab species. This would al1ow

~~~

One could argue that consumer benefits and taxbasis would be created if these species areproduced for the domestic market. On the otherhand, consumer benefits and tax basis arecreated from export earnings when companiesthat produce roe rock sole are allowed to

29

individual fishing operations to fish at a pace thatis better able to avoid prohibited species catches.This approach provides a means of avoiding theimpetus to fish as fast as possible before the totalprohibited species cap is met and thf: fisherycloses, as currently occurs.

would flow to entities with high bycatch ratesand a greater ability to pay for bycatch rights.This argument ignores the fact that, in the longrun, firms that catch lower amounts of targetcatch per unit of by catch will be unprofitable andexit the fishery. The willingness to pay forbycatch rights by firms that fish cleanly willrepresent a huge opportunity cost for rights heldinitially by firms that cannot fish with lowbycatch rates.

With individual allotments of bycatch of PSCs,operations may be able to slow do\\/fi therefishing pace and not incur the costs crt~ted bythe externality of being affected by other fisheryparticipants' bycatch behavior in the face of atotal overall cap for the fishery. Loss of rev-enue from a premature closure of the r(ICk solefishery by other fishing operations would nolonger be a possibility because the costs offishing indiscriminately would be internalized byfishing operations that cannot fish cleanly, ratherthan externalized to the whole fleet. Withindividual bycatch allotments, flrInS may be ableto adjust to a higher retention standard with farless economic cost to the industry and the nationthan if the retention standard alone was required.Individual bycatch quotas have been attempted inthe high seas purse seine fishery for yellowfinand skipjack tuna with some success. Thatprogram has accomplished some individualaccountability and allowed fishermen to makeadjustments in fishing practices without facingexternalities of a fleet-wide closure as a total capis attained. That approach has also effectivelyremoved the worst offenders in terms of bycatchfrom the fishery.

Markets to efficiently allocate effluent rights arecurrently being used in regulation of pollution inthe manufacturing industry. Experience withthat approach may some day convince environ-mental groups of the merits of market-basedapproaches to environmental and resource man-agement.

REFERENCES

Natural Resource Consultants. 1994. A GlobalAssessment of Fisheries Bycatch and Discard(Final Report). Dayton Alverson, editor.Unpublished manuscript. Seattle,Washington.

Pacific Associates. 1994. Discards in theGroundfish Fisheries of the Bering Sea /Aleutian Islands & the Gulf of Alaska Dur-ing 1993. A report prepared for the AlaskaDepartment of fish and Game. Unpublishedmanuscript. Juneau, AK.

U.s. Department ofComrnerce. NOAA. NMFS.1994. Stock Assessment and Fishery Evalu-ation for the Groundfish Resources of theBering Seal Aleutian Islands Regions asProjected in 1994. Alaska Fisheries ScienceCenter. Seattle, W A

A controversial but potentially promising meansof making individual bycatch quotas effective forrock sole would be to make quotas tradable.Such a system could allow more target cat(;h perunit of bycatch or perhaps the same directedcatch with far less bycatch. Both of these areeconomically efficient outcomes. The mechan-ism that allows achievement of improved utiliz-ation efficiently is a market for bycatch shares.Such a market would tend to allocate rights tothose who fish with lower bycatch rates becausethose individuals would be able to catch moredirected catch per unit of bycatch. Thus tradingbycatch shares would allow bycatch units to flowto those who make best economic use of thebycatch.

North Pacific Fishery Management Council.1992. Amendment 12A to the FisheryManagement Plan for Bering Sea andAleutian Islands Groundfish (ProhibitedSpecies Caps). Anchorage, AK.

Some environmental groups oppose this approachas a potential solution because they believe rights

30

FIGURE 1: Eastern Bering Sea Rock Solebioma~;s trends 1975-1994

I

I

1

Figure 2. EXPLOITATION RATE FOR ROCK SOLE IN THEEAS1-eRN BERING SEA

~

2500~";j

nole actual catch 01 rocksole IS less than 3% 01 theesumated biomass in 1994.Rock sole T AC is set at a low

level because of the 2 millionmetric ton(ecosystem) capon aS/AI removals and the

Industry's prelerence 101'

pollock

_"1~

$4JUtce NMfS SAFE Report, NMFS Final Spec;ro:ationslot n.. Gfoundrlsh Fish8riH oIlhe Berwog se. AleutianIslanll$l199.)