Ecosystem_tradeoffs_in_managing_New_England_fisheries
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This document discusses ecosystem trade-offs in managing New England fisheries. It describes conflicting legislative mandates around maximizing catch while preventing overfishing. Trade-offs are illustrated in the sea scallop fishery, where rotational area closures increased scallop densities and yields but reduced fishing areas. In groundfish fisheries, overfishing of species like haddock and cod required rebuilding plans involving catch limits and closed areas. Managing fisheries requires balancing ecological and economic objectives, which remains an ongoing challenge under an ecosystem approach.
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- 1. ECOSYSTEM TRADE-OFFSECOSYSTEM TRADE-OFFS IN MANAGINGIN MANAGING NEW ENGLAND FISHERIESNEW ENGLAND FISHERIES Jon BrodziakJon Brodziak National Marine Fisheries ServiceNational Marine Fisheries Service Northeast Fisheries Science CenterNortheast Fisheries Science Center Woods Hole, MA 02543Woods Hole, MA 02543
- 2. 30 second grid resolution = 0.9 km This map = 1.25km/pixel SRTM30_PLUS: SRTM30, COASTAL & RIDGE MULTIBEAM, ESTIMATED TOPOGRAPHY Joseph J. Becker & David T. Sandwell Shelf Region Median Depth (m) Middle Atlantic Bight 34 Southern New England 58 Georges Bank 70 Gulf of Maine 176 Northeast USA continental Shelf Ecosystem
- 3. • Conflicting Legislative MandatesConflicting Legislative Mandates • Trade-Offs in Sea Scallop FisheriesTrade-Offs in Sea Scallop Fisheries • Trade-Offs in Groundfish FisheriesTrade-Offs in Groundfish Fisheries • Trade-Offs in Pelagic FisheriesTrade-Offs in Pelagic Fisheries • Applying an Ecosystem ApproachApplying an Ecosystem Approach in New England fisheries –in New England fisheries – Is there a clear path forward?Is there a clear path forward? OverviewOverview
- 4. Conflicting Mandates • Magnuson-Stevens Fishery Conservation and Management Act • Marine Mammal Protection Act • Endangered Species Act • National Environmental Policy Act • Regulatory Flexibility Act
- 5. •National Standard 1 •Achieve Optimum Yield •Prevent Overfishing •National Standard 8 •Maintain Fishing Communities •National Standard 9 •Minimize Bycatch Potential Conflicts betweenPotential Conflicts between MSFCMA National StandardsMSFCMA National Standards
- 6. “optimum … means the amount of fish that will provide the greatest overall benefit to the Nation … taking into account the protection of marine ecosystems” - Magnuson-Stevens Fishery Conservation “Conservation and management measures shall prevent overfishing while achieving, on a continuing basis, the optimum yield from each fishery”
- 7. When scallopers dream ... Trade-Offs in Scallop Fisheries
- 8. 3.96 6.927 6.275 3.025 Area I Area II Nantucket Light W. Gulf of Maine 0 1 2 3 4 5 6 7 8 Thousands of Square Kilometers Groundfish Closed Areas Total Area: 20,200 km2 W. Gulf of Maine Nantucket Lightship Area I Gulf of Maine USA Canada Area II
- 9. 1983 1986 1989 1992 1995 1998 2001 ScallopDensity(kg/tow,meats) 0 2 4 6 8 10 12 14 16 18 20 22 Overall Density Closed Areas Open Areas An Unintended Experiment
- 10. (A) Year 1980 1985 1990 1995 2000 2005 NominalFishingEffort 0 5000 10000 15000 20000 25000 30000 Days fished Days absent Sea Scallop Fishing Effort
- 11. (B) Year 1980 1985 1990 1995 2000 2005 Fisheryyield(mt) 0 2000 4000 6000 8000 10000 12000 Landingsperuniteffort(mt/day) 0.0 0.2 0.4 0.6 0.8 1.0 1.2 Landings Landings per day absent Landings per day fished Sea Scallop Catch Rates
- 12. Sea Scallop Yield GB and SNE Year 1980 1985 1990 1995 2000 2005 Landings(mt) 0 2000 4000 6000 8000 10000 12000
- 14. Scallop Yield Per Recruit using Rotational Areas FAVG (y-1 ) 0.0 0.2 0.4 0.6 0.8 YPRAVG (g) 0 2 4 6 8 10 12 14 16 18 No rotation 3 yr rotation 6 yr rotation 9 yr rotation Rotation at high fishing mortalities allows some scallops to grow to a large size, no matter how high the mortality rate.
- 15. Where do we go from here?Where do we go from here? • Rotational area management • Biological reserves for spawning stock • Explicit tradeoffs • Scallop fishery access versus EFH • Scallop fishery yield versus bycatch • Stewardship and property rights
- 16. Essential Fish Habitat: Protection of Benthic Biodiversity Benthic megafaunal production within Georges Bank Closed Areas increased by 3- to 10-fold versus comparable disturbed sites (Hermsen et al. 2003. MEPS 260:97-108)
- 17. Year 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 AverageNumberofSpeciesPerHaul 9 10 11 12 13 14 15 16 80th Percentile 20th Percentile Georges Bank Total Species Diversity Updated from Brodziak and Link (2002. Bulletin of Marine Science. 70:589-611) Do Georges Bank MPAs affect biodiversity?
- 18. Feedback Habitat Effects Environmental Variation (trend, variance) Fishery Effects Resource Species (intermediate consumer) Apex Predator Intermediate Pelagic Trophic Level Lower Pelagic Trophic Levels Confounding Factors and the Burden of Proof Density Dependence Benthostrophic cascade yield yield trophic cascade sinkprey prey prey sink fishing gear impacts yield yield Regime Shifts o environmentally driven o fishery driven ? Flow Indirect Effects ? prey
- 19. Minimize Bycatch of Protected Species Scallop fishing gear modifications helped reduce loggerhead turtle bycatch in MAB from 749 turtles in 2003 to 180 in 2004
- 20. •History of Chronic Overfishing • Sequential Depletion & Species Write-Offs – Now Some Write-Ins •Management by Lawsuit - Conservation Law Foundation 1991 - Conservation Law Foundation et al. 1999 •Revised Biomass Targets - Moving the Goal Posts for Rebuilding Trade-Offs in Groundfish Fisheries
- 21. Georges Bank Haddock Spawning Stock Biomass (kt) 0 20 40 60 80 100 120 140 160 180 200 FishingMortality 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 Target F Limit F Observed F 1998 Haddock Harvest Control Rule, 1931-1998 Chronic overfishing of Georges Bank haddock
- 22. Haddock, Closed Area I year 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 RatioofcatchesInside/Outside(lnkg/tow+1) 0 2 4 6 8 10 12 14 16 20 24 28 Area closed Closed Area Effects on Georges Bank haddock
- 23. Year 1930 1940 1950 1960 1970 1980 1990 2000 Fishingmortality 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 FMSY Georges Bank Haddock The Intended Experiment: Reduced Fishing Mortality
- 24. Haddock Spawning Biomass (kg) Per Recruit: What Is the Effect of Allowing Fish to Spawn More Than Once Before You Catch Them?
- 25. Year 1930 1940 1950 1960 1970 1980 1990 2000 Recruitment 0 50 100 150 200 250 300 350 400 450 500 750 760 770 780 790 Average 1931-1960 Average 1980-1993 Georges Bank Haddock Can we please return to the good old days ?
- 26. Spawning Stock Biomass ('000 t) 0 25 50 75 100 125 150 175 200 Age1Recruits(millions) 0 25 50 75 100 125 150 175 200 1931-1963 YCs 1964-2000 YCs '62 YC '75 YC '00 YC (486) '63 YC Odds of above-average recruitment are over 20-fold greater when SSB > 80 kt Brodziak et al. (2001. CJFAS 58:306-318) The importance of maternal effects
- 27. Year 1930 1940 1950 1960 1970 1980 1990 2000 Spawningbiomass(kt) 0 25 50 75 100 125 150 175 200 225 250 275 300 BMSY Georges Bank Haddock Moving the goalposts for rebuilding groundfish
- 28. GARM II: Groundfish Fishing Mortality Fishing mortality 0.0 0.5 1.0 1.5 2.0 2.5 3.0 GM cod GB cod GB haddock GB yellowtail SNE yellowtail FMSY F2004 F 1994 Tracking the Big Five groundfish stocks
- 29. GARM II: Groundfish Biomass Spawning biomass (thousand mt) 0 50 100 150 200 250 300 GM cod GB cod GB haddock GB yellowtail SNE yellowtail Rebuilding target SSB 2004 1994 Some positive signs, but there’s a long way to go
- 30. Groundfish status at the start of Amendment 13
- 31. Atlantic cod fishery (millions of pounds) Georges Bank and Gulf of Maine stocks 0 10 20 30 40 Fishing year 1998-99 1999-00 2000-01 2001-02 2002-03 2003-04 2004-05 Target TAC Landings Amendment 13 went into effect on May 1, 2004
- 32. 2004 2006 2008 2010 2012 2014 SpawningStockBiomass FishingMortalityRate(F) current Bmsy F = Fmsy = 0.230 F = Frebuild = 0.217 An Adaptive Management Approach for Gulf of Maine Cod VPA Stock Size Estimates for 2008 Upper Quartile Median Lower Quartile B2008 = 51 Amendment 13: incorporating flexibility
- 33. B2008 > Bwaypoint B2008 = B waypoint B2008 < Bwaypoint F2002-08 > Fmsy Reduce F to Fmsy, re-consider Bmsy, Fmsy Reconsideration should come before reduction in F. Identify causes—strong recruitment offset overfishing? Reduce F to Frebuild Extra measures will be needed since present measures ineffective. Identify causes—strong recruitment offset overfishing? Reduce F to F rebuild; Consider basis for poor biomass performance Extra measures will be needed since present measures ineffective. F2002-08 = Fmsy Maintain F at Fmsy or below Depends on expected trajectory from B’08 to B’14 at Fmsy. Reduce F to Frebuild Proceed with plan. Consider revising F rebuild if value for 2009-2014 greater than previous value Reduce F to Frebuild; and/or re-estimate Bmsy, Fmsy as appropriate Consider regime changes, multispecies effects, changes in vital rates F2002-08 < Fmsy Maintain F </= Fmsy, re- consider Bmsy Reconsider time frame for rebuild. No penalty for early victory. Re-evaluate Fmsy (too low?) If F2008 will rebuild to Bmsy, maintain F Consider basis, re- estimate Bmsy, Fmsy as appropriate Consider regime changes, multispecies effects, and changes in vital rates Waypoint in 2008: Adaptive Management Contingency Table
- 34. What changes would improve quality ? Is more information needed ? Carry out change or test. Collect new data if needed. Observe the effects of the change or test. Study the results. What did we learn ? What can we predict ? The Shewhart cycle for total quality management Adaptive management is an objective approach for improving ecosystem quality
- 35. ““No one knew exactly how many newcomers had arriveNo one knew exactly how many newcomers had arrive during the last four months of 1977, but according toduring the last four months of 1977, but according to one report, new boats entered the fishery at theone report, new boats entered the fishery at the astounding rate of about one every four days.”astounding rate of about one every four days.” Industry in TroubleIndustry in Trouble Margaret DewarMargaret Dewar Overcapacity to Harvest Fishery Resources After the 200-Mile Limit
- 36. Number of Otter Trawl Vessels Landing in New England, 1964-2000 0 200 400 600 800 1000 1200 1964 1968 1972 1976 1980 1984 1988 1992 1996 2000 Year t) #) Ò) Increasing Harvest Capacity Indices
- 37. Average Income of New England Otter Trawl Fishermen, 1964-2000 (adjusted to year 2000US$) $0 $20,000 $40,000 $60,000 $80,000 $100,000 $120,000 $140,000 $160,000 1964 1968 1972 1976 1980 1984 1988 1992 1996 2000 Year Average per crew Average per vessel Working harder for less
- 38. Beware, Latent Effort is Lurking Multispecies Groundfish Days at Sea Year 1996 1997 1998 1999 2000 2001 2002 2003 2004 Groundfishdaysatsea(thousands) 0 50 100 150 200 250 300 Allocated Used
- 39. •Rebuilding Groundfish Stocks versus Maintaining Communities • Share-Based Harvesting Rights (IFQs) versus Freedom to Fish Trade-Offs in Groundfish Fisheries
- 40. Trade-Offs in Pelagic Fisheries
- 41. (A) Atlantic herring Year 1920 1930 1940 1950 1960 1970 1980 1990 2000 Yield(thousandmt) 0 100 200 300 400 500 Landings Forgone yield, 1977-present Herring Fishery Yield
- 42. Year 1965 1970 1975 1980 1985 1990 1995 2000 Spawningbiomass(thousandmt) 0 500 1000 1500 2000 Meanlength(cm)duringAugust 26 27 28 29 30 31 32 33 Spawning biomass Age-5 mean length Herring Density-Dependent Growth
- 43. Herring Density-Dependent Growth Year 1965 1970 1975 1980 1985 1990 1995 2000 Spawningbiomassindex(kg/tow) 0 2 4 6 8 10 12 Meanlength(cm)duringAugust 20 22 24 26 28 30 32 Age-3+ biomass Age-4 Mean length
- 44. Year 1975 1980 1985 1990 1995 2000 Biomass(thousandmt) 0 50 100 150 200 250 300 Herring consumed by fish Fishery landings Herring Fish Predators Versus Fishery Yield
- 45. Trends in Pelagic and Demersal Species Biomasses Gulf of Maine Year 1965 1970 1975 1980 1985 1990 1995 2000 2005 Demersalbiomassperarea(mt/km2 ) 0 2 4 6 8 10 12 14 16 Pelagicbiomassperarea(mt/km2) 0 2 4 6 8 10 12 14 Demeral Pelagic Georges Bank Year 1965 1970 1975 1980 1985 1990 1995 2000 2005 Demersalbiomassperarea(mt/km2) 0 5 10 15 20 25 30 Pelagicbiomassperarea(mt/km2) 0 5 10 15 20 25 30 Demeral Pelagic Southern New England Year 1965 1970 1975 1980 1985 1990 1995 2000 2005 Demersalbiomassperarea(mt/km2) 0 5 10 15 20 25 Pelagicbiomassperarea(mt/km2) 0 5 10 15 20 25 Demeral Pelagic Mid-Atlantic Bight Year 1965 1970 1975 1980 1985 1990 1995 2000 2005 Demersalbiomassperarea(mt/km2) 0 5 10 15 20 25 Pelagicbiomassperarea(mt/km2) 0 2 4 6 8 10 12 14 16 Demeral Pelagic
- 46. Trade-Offs in Pelagic Fisheries •Limited Incentives for Fishing versus Forgone Yield • Density-Dependent Growth versus Keeping Fishing Mortality Low •Fishery Yield versus Predator Consumption • Demersal versus Pelagic Dominance of Energy Flux?
- 47. • Conserve Fisheries Resources • Use Marine Protected Areas • Reduce Bycatch and Discards • Improve Management Institutions • Reduce Excess Fishing Capacity Applying an Ecosystem Approach to Manage New England Fisheries
- 48. Metrics of Ecological Sustainability in Ecosystem Management – Measuring Success • Diverse Biota • Mature Fish Thriving and Spawning • Reliable Seafood Products • Low-Impact Fishing Practices • Resilience to Climate Ecological Change • Stable Yields • Profitable Industries • Ample Recreational Fishing and Tourism Opportunities • Robust Populations of Protected Species
- 49. The Participatory Process and Political Intervention Incorporating Other Ocean Uses and Services
- 51. Insufficient Knowledge and Attacking the Credibility of Science
- 52. Inadequate Monitoring, Higher Data Costs, and Aligning Public Expectations with Reality “during the 1980s … the … administration substantially cut the budget of the NMFS. Congress not only failed to restore the agency’s budget but went on to expand greatly its regulatory mandate.” (Hennessey and Healey (2000)
- 53. Fishing Down the Food Web – Can We Restore Marine Ecosystems? Adapted from Pauly et al. (1998. Fishing Down Marine Food Webs)Source: Pauly et al. (1998)
- 54. The Participatory Process and Political Intervention “Under intense political pressure, NOAA eventually acquiesced to a plan (in 1986) that its fishery experts believed was fundamentally flawed” (Hennessey and Healey(2000)
- 55. Overcapacity !!! “…the groundfish fishery includes about 1663 permits [circa 2002], but less than 30% of this level may be more than sufficient to land the maximum sustainable yield (Kirkley et al. (2002).”
- 56. Stressed ecosystem overcapacitymany competing uses Alternative ecosystem states -some uses in moderation -some uses not at all -regulation of all uses high information requirements more variability less resilience more stable yields fewer but more productive vessels Transition costs: -fleet reductions -restructuring of fishing communities -allocation Robust and productive ecosystem Transition benefits: -more stable fish communities -more stable fishing communities -share-based harvest rights habitat damage lower fishing mortality Adapted from Brodziak et al. (2004) Where do we go from here?
- 57. Building Responsible Fisheries • Goals and Constraints • Conservation of Fisheries Resources • Allocation of Fishing Rights • Participatory Decision-Making • Ecosystem Protection • Management Support • The Ethic of Restraint Adapted from Sissenwine and Mace (2001. Governance for responsible fisheries: an ecosystem approach. FAO)
- 58. Brodziak, J.K.T., P. M. Mace, W.J. Overholtz, and P.J. Rago. 2004. Ecosystem Trade-Offs in Managing New England Fisheries. Bulletin of Marine Science. 74:529-548. For more information:For more information:
- 59. Ecological Decision Making in the Face of Diverse Human Value Systems • Accountability: Explicit About Decision Criteria • Legitimacy: Explicit About Policy Strategies • Flexibility: Explicit About Uncertainties
Editor's Notes
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