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Status of the Southeastern Bering Sea – Upper Trophic Level and Aggregate Indicators

Status of the Southeastern Bering Sea – Upper Trophic Level and Aggregate Indicators. Linking Ecosystem-Based Management Goals with Ecosystem Research. FATE. Fisheries And The Environment. CLIMATE and FISHING. I. ECOSYSTEM ASSESSMENT Objectives for Ecosystem Protection:.

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Status of the Southeastern Bering Sea – Upper Trophic Level and Aggregate Indicators

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  1. Status of the Southeastern Bering Sea– Upper Trophic Level and Aggregate Indicators Linking Ecosystem-Based Management Goals with Ecosystem Research FATE Fisheries And The Environment

  2. CLIMATE and FISHING I. ECOSYSTEM ASSESSMENTObjectives for Ecosystem Protection: • Maintain predator-prey relationships • pelagic forage availability • spatial/temporal conc. of fishery impact on forage fish • removals of top predators • introduction of non-native species • Maintain diversity • species diversity • functional (trophic, structural habitat) diversity • genetic diversity • Maintain energy flow and balance • human-induced energy redirection • system impacts attributable to energy removal

  3. BS Trophic level Ice Cover Index AI Trophic level Surf. Winter Air Temp. Total salmon catch PDO Herring recruits May SST COMU Productivity AOI Atka (R/S) Total CPUE BS Diversity Jellyfish biomass AK Plaice (R/S) Cod (R/S) Pollock (R/S) BS Richness Total crab biomass BLKI Productivity TBMU Productivity RLKI Productivity YFS (R/S) POP (R/S) Northerns (R/S) GT (R/S) ATF (R/S) Rock sole (R/S) FHS (R/S) Summer Bottom Temp. Hook and Line Effort AI Bottom Trawl Duration BS Bottom Trawl Duration BS Pelagic Trawl Duration 1975 1980 1985 1990 1995 2000 1970 Bering Sea/Aleutian Islands

  4. Objectives for Ecosystem Protection: • Maintain predator-prey relationships by examining: • pelagic forage availability • spatial/temporal conc. of fishery impact on forage fish • removals of top predators • introduction of non-native species • Maintain diversity by examining: • species diversity • functional (trophic, structural habitat) diversity • genetic diversity • Maintain energy flow and balance by examining: • human-induced energy redirection • system impacts attributable to energy removal

  5. Objectives for Ecosystem Protection: • Maintain predator-prey relationships by examining: • pelagic forage availability Significance threshold: changes outside natural variability for prey relative to predator demands Indicators: -NMFS bottom trawl survey catches of forage fish -BASIS surveys -age-0 pollock (BS) -ADFG herring -Groundfish trends -Groundfish fishery bycatch amounts -Bristol Bay sockeye salmon

  6. FORAGE –NMFS (Lauth)

  7. FORAGE –Togiak Herring (F. West) Abundance Biomass Age-4 recruits Catch 400 2000 200 1000 Abundance & Recruits (millions fish) 0 0 1998 1993 2003 1988 1978 1983 Biomass and Catch (1,000s mt)

  8. FORAGE – Juvenile sockeye and pollock -BASIS (Eisner et al.) 2000 2001 2002 2003 2004 Juvenile Sockeye Counts Age-0 Pollock Counts

  9. Bristol Bay Sockeye Salmon(L. Fair)

  10. Groundfish B.Sea 0.40 0.20 YFS ATF 0.30 POLLOCK 0.10 0.20 0.20 0.10 0.00 0.00 -0.10 0.00 -0.10 -0.20 -0.20 -0.20 0.20 2002 2002 1996 1996 ROCK SOLE 1984 1984 1960 1960 1966 1966 1972 1972 1978 1978 1990 1990 0.60 COD 0.40 0.00 0.20 0.00 -0.20 -0.20 -0.40 FH SOLE 0.40 0.40 GT 0.20 0.20 0.00 0.00 -0.20 -0.20 -0.40 1.00 AK PLAICE 1960 1966 1972 1978 1984 1990 1996 2002 0.50 0.40 POP 0.00 0.20 -0.50 0.00 NORTHERNS 0.20 -0.20 0.10 -0.40 0.00 2002 1960 1966 1972 1978 1984 1990 1996 -0.10 0.30 AI ATKA 0.20 0.10 0.00 -0.10 1960 1966 1972 1978 1984 1990 1996 2002 1976/77 shift 1988/89 shift Other shift R/S Anomalies

  11. Groundfish – Combined Std. Indices of Recruitment and Survival (Mueter)

  12. Biological Response to Climate Flatfish Distribution-(Spencer)

  13. Objectives for Ecosystem Protection: • Maintain predator-prey relationships by examining: • pelagic forage availability • spatial/temporal conc. of fishery impact on forage fish • removals of top predators • introduction of non-native species • Maintain diversity by examining: • species diversity • functional (trophic, structural habitat) diversity • genetic diversity • Maintain energy flow and balance by examining: • human-induced energy redirection • system impacts attributable to energy removal

  14. Objectives for Ecosystem Protection: • Maintain predator-prey relationships by examining: • pelagic forage availability • spatial/temporal conc. of fishery impact on forage fish • removals of top predators • introduction of non-native species • Maintain diversity by examining: • species diversity • functional (trophic, structural habitat) diversity • genetic diversity • Maintain energy flow and balance by examining: • human-induced energy redirection • system impacts attributable to energy removal Significance threshold: catches high enough to cause biomass of top predator(s) to fall below min. biol. acceptable limits Indicators: -Trophic level of the catch -Population status of top predators • -Fishing takes of top predators • -Seabird incidental take

  15. TOP PREDATORS – Trophic level of the catch 4 2,000 3 Trophic level catch 1,000 2 1 0 3.0 2.0 FIB Index Total catch (1000 t) 1.0 0.0 1960 1970 1980 1990 2000 1960 1970 1980 1990 2000 FIB= index that shows a decline in TL only when catches do not increase as expected

  16. TOP PREDATORS 325 50 St. Paul St. George 275 40 225 30 Pups born (1,000's) 175 20 125 10 73 78 83 88 93 98 03 73 78 83 88 93 98 03 • Northern fur seal pup production continued decline (Sinclair et al.)

  17. TOP PREDATORS – Seabirds(Fitzgerald et al.) Seabird Breeding Chronology Seabird Population Trends 12 18 16 10 14 8 12 Frequency Frequency 10 6 8 4 6 4 2 2 0 0 N.BS/Chuk. SE BS SW BS GOA SEAK N.BS/Chuk. SE BS SW BS GOA SEAK Negative trend >3days earlier than average No discernable trend Seabird Productivity Levels =within 3days of average Positive trend 16 >3 days later than average 14 >20% below average 12 Within 20% of average 10 >20% above average Frequency 8 6 4 2 0 N.BS/Chuk. SE BS SW BS GOA SEAK

  18. TOP PREDATORSSeabird Incidental Take(Fitzgerald et al.) 300,000 0.2 BSAI Effort Incidental take 250,000 0.16 200,000 0.12 150,000 0.08 100,000 0.04 50,000 0 0 0.1 1996 1997 1998 1999 2000 2003 1993 1994 1995 2001 2002 Fishing Effort (in 1,000's of hooks) Incidental take rate (per 1,000 hooks)

  19. PREDATOR-Bering Sea Jellyfish (Walters) 400,000 350,000 300,000 250,000 Biomass (t) 200,000 150,000 100,000 50,000 0 2002 2004 1986 1988 1990 1992 1994 1996 1980 1982 1984 1998 2000

  20. Objectives for Ecosystem Protection: • Maintain predator-prey relationships by examining: • pelagic forage availability • spatial/temporal conc. of fishery impact on forage fish • removals of top predators • introduction of non-native species • Maintain diversity by examining: • species diversity • functional (trophic, structural habitat) diversity • genetic diversity • Maintain energy flow and balance by examining: • human-induced energy redirection • system impacts attributable to energy removal

  21. Objectives for Ecosystem Protection: • Maintain predator-prey relationships by examining: • pelagic forage availability • spatial/temporal conc. of fishery impact on forage fish • removals of top predators • introduction of non-native species 2. Maintain diversity by examining: a. species diversity Significance threshold:catch high enough to cause biomass to fall below or be kept from recovering from min. biol. acceptable limits Indicators: -Status of protected and managed stocks relative to thresholds -Species richness and diversity -Areas closed to fishing -Pop’n trends -other nontarget species from surveys (eg. eelpouts) -Bycatch trends of sensitive species lacking population estimates

  22. Ecosystem Mngt Info. –Area closures(Coon)

  23. SPECIES DIVERSITY – Species richness and diversity (Mueter) Shannon-Wiener index Richness= number of species per haul Diversity= function of number of species and relative abundance per haul

  24. Objectives for Ecosystem Protection: • Maintain predator-prey relationships by examining: • pelagic forage availability • spatial/temporal conc. of fishery impact on forage fish • removals of top predators • introduction of non-native species • Maintain diversity by examining: • species diversity • functional (trophic, structural habitat) diversity • genetic diversity • Maintain energy flow and balance by examining: • human-induced energy redirection • system impacts attributable to energy removal

  25. Objectives for Ecosystem Protection: 2. Maintain diversity by examining: b. Functional (trophic and structural habitat) diversity Significance threshold: catch high enough to cause change outside observed natural variability Indicators: -guild or size diversity -bottom gear effort -HAPC biota bycatch -habitat research: Distribution of deep-water corals in AI Seafloor mapping and colonization studies Effects of trawling on benthic habitat Growth and recruitment of coral Spatial and temporal patterns in BS invertebrate assemblages

  26. Demersal fish community size spectrum, 1982-2002 (Bartkiw et al.) a Through time: fewer small individuals and more large individuals

  27. SPECIES DIVERSITY-Bottom trawl effort(Coon) 3500 3000 2500 2000 Observed Bottom Trawl duration (24 hour days) 1500 BS GOA 1000 AI 500 0 2004 1990 1992 1994 1996 1998 2000 2002

  28. FUNCTIONAL DIVERSITY – HAPC Biota (Lauth)

  29. Objectives for Ecosystem Protection: • Maintain predator-prey relationships by examining: • pelagic forage availability • spatial/temporal conc. of fishery impact on forage fish • removals of top predators • introduction of non-native species • Maintain diversity by examining: • species diversity • functional (trophic, structural habitat) diversity • genetic diversity • Maintain energy flow and balance by examining: • human-induced energy redirection • system impacts attributable to energy removal

  30. Objectives for Ecosystem Protection: 3. Maintain energy flow and balance by examining: a. human-induced energy redirection Significance threshold: long-term changes in system biomass, respiration, production, energy-cycling due to discards and offal Indicators: -Prohibited species bycatch amounts -Nontarget catch and discards -Groundfish discards -Trends in scavenger species

  31. 400 15000 CHINOOK SALMON BAIRDI CRAB OTHER SALMON OTHER TANNER CRAB 300 10000 No. fish (1000s) No. of crab (1000s) 200 5000 100 0 0 300 8000 HALIBUT MORTALITY HERRING BYCATCH RED KING CRAB 6000 OTHER KING CRAB 200 No. of crab (1000s) Metric tons 4000 100 2000 0 0 1995 1996 1994 1997 1998 1999 2000 2001 2002 2003 2004 1999 2000 2001 2002 2003 2004 1994 1995 1996 1997 1998 ENERGY REDIRECTIONProhibited Catch(Hiatt and Terry)

  32. ENERGY REDIRECTIONDiscards(Hiatt and Terry) Bering Sea/Aleutian Islands Tonnage discarded 16% Percent discarded 300 12% 200 Discard rate 8% Discards (1000 t) 100 4% 0 0% 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 Improved retention regulations

  33. Objectives for Ecosystem Protection: • Maintain predator-prey relationships by examining: • pelagic forage availability • spatial/temporal conc. of fishery impact on forage fish • removals of top predators • introduction of non-native species • Maintain diversity by examining: • species diversity • functional (trophic, structural habitat) diversity • genetic diversity • Maintain energy flow and balance by examining: • human-induced energy redirection • system impacts attributable to energy removal

  34. Objectives for Ecosystem Protection: 3. Maintain energy flow and balance by examining: b. system impacts attributable to energy removal Significance threshold: long-term changes in system biomass, respiration, production, energy-cycling due to fishery removals of energy Indicators: -Total catch relative to production

  35. ENERGY REMOVAL -Total Catch

  36. ENERGY REMOVAL– ASP(Mueter) 7000 Bering Sea 6000 Gulf of Alaska 5000 4000 ASP (1000 mt) 3000 2000 1000 0 -1000 1400 300 1200 250 1000 200 GOA ASP (1000 mt) 800 150 600 BS ASP (1000 mt) 100 400 50 200 0 0 2004 2002 2000 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 1978

  37. Management Goals Groundfish FMP Goals Ecosystem Assessment Objectives • Maintain predator-prey relationships • Maintain diversity • Maintain energy flow and balance • Prevent overfishing • Promote sustainable fisheries and communities • Preserve food web • Manage incidental catch and reduce bycatch and waste • Avoid impacts to seabirds and marine mammals • Reduce and avoid impacts to habitat • Promote equitable and efficient use of fishery resources • Increase Alaska native consultation • Improve data quality, monitoring and enforcement

  38. Ecosystem Considerations Indices Groundfish FMP Goals Status of stocks, annual surplus productivity Fishing overcapacity programs Pelagic forage availability, spatial/temporal conc. of fishery impact on forage fish, removals of top predators, introduction of non-native species Prohibited species, discards, bycatch, scavenger population trends Seabird and mammal incidental take, population abundance, productivity, and chronology trends EFH research, effects of fishing gear on habitat research Fishing overcapacity programs, groundfish fleet composition ANTEK of climate regimes Prevent overfishing Promote sustainable fisheries and communities Preserve food web Manage incidental catch and reduce bycatch and waste Avoid impacts to seabirds and marine mammals Reduce and avoid impacts to habitat Promote equitable and efficient use of fishery resources Increase Alaska native consultation Improve data quality, monitoring and enforcement

  39. Executive Summary • CLIMATE • North Pacific in uncertain state • BS continues to warm, less sea ice and earlier retreat • BIOLOGY • BS summer zooplankton biomass: low 2000-2004 • BS jellyfish biomass: low 2000-2004 • Warming trend may affect flatfish distribution • Most seabirds show no discernable population trend • 2002 seabird breeding chronology was early • 2004 N. fur seal pups born continued to decline • ASP in BS decreased from 1978-2004 • FISHERY EFFECTS • 2003 and 2004 increases in herring and other salmon bycatch • 2003 seabird incidental take rate same as 2002

  40. Website: Geoff Lang http://access.afsc.noaa.gov/reem/ecoweb/index.cfm

  41. Summary • No noted significant adverse impacts of fishing on the ecosystem (relating to predator/prey interactions, energy flow/removal, or diversity). • There are gaps in understanding the system-level impacts and spatial/temporal effects of fishing on community structure and prey availability. • Future: incorporate predictions from multispecies models. • Need research, validation of models, and models focused on understanding spatial processes, and improvements in monitoring systems • A range of possible climate scenarios and plausible effects on recruitment should be entertained.

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