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THE ROLE OF HARVEST CONTROL LAWS, RISK AND UNCERTAINTY AND THE PRECAUTIONARY APPROACH IN ECOSYSTEM-BASED MANAGEMENT. DOUG BUTTERWORTH - UNIVERSITY OF CAPE TOWN ANDRE PUNT - UNIVERSITY OF WASHINGTON. HARVEST CONTROL LAWS RISK UNCERTAINTY PRECAUTIONARY APPROACH. WHAT’S THE
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THE ROLE OF HARVEST CONTROL LAWS, RISK AND UNCERTAINTY AND THE PRECAUTIONARYAPPROACH IN ECOSYSTEM-BASED MANAGEMENT DOUG BUTTERWORTH- UNIVERSITY OF CAPE TOWN ANDRE PUNT- UNIVERSITY OF WASHINGTON
HARVEST CONTROL LAWS RISK UNCERTAINTY PRECAUTIONARY APPROACH WHAT’S THE CONNECTION ?
UNIFIED WITHIN THE OPERATIONAL MANAGEMENT PROCEDURE(OMP) OR MANAGEMENT STRATEGY EVALUATION(MSE) APPROACH TO FISHERY MANAGEMENT
TRADITIONAL MANAGEMENT APPROACH BEST ASSESSMENT OF STOCK BIOLOGICAL REFERENCE POINT TAC
MANAGEMENT PROCEDURE APPROACH • SPECIFY DATA TO BE USED • SPECIFY FORMULA TO CONVERT DATA TO TAC (FORMULA = HARVEST CONTROL LAW) • USE PRIOR COMPUTER SIMULATION TO CHECK THAT IT WILL WORK
SIMPLE EXAMPLE SOUTH AFRICAN SARDINE FISHERY MANAGEMENT • DATA: ANNUAL HYDROACOUSTIC SURVEY ABUNDANCE ESTIMATE • FORMULA:TAC = 0.1375 x ABUNDANCE ESTIMATE • BUT • TAC CHANGE < 25% ? HOW CHOSEN ?
WILL FORMULA WORK EVENIF BEST ASSESSMENT IS WRONG? KEY NEW FEATURE REASONABLY HIGH CATCHES REASONABLY LOW RISK OF COLLAPSE SCIENTIFIC UNCERTAINTY PRECAUTIONARY APPROACH “WORK” “WRONG”
KEY NEW FEATURE PROPERCONSIDERATION OF RISK INVOLVES REPEATED APPLICATION OF FORMULA OVER MANY YEARS
DECISION-MAKER ROLE CHOOSE FORMULA GIVING DESIRED TRADE-OFF AMONG • AVERAGE SIZE OF TAC • RISK TO RESOURCE • TAC VARIABILITY BETWEEN YEARS
! PROBLEM ! RISK DEFINITION OVER HOW WIDE A RANGE OF UNCERTAINTY MUST THE FORMULA WORK?
THE MANAGEMENT PROCEDURE (OMP/MSE) APPROACH INTEGRATES • HARVEST CONTROL LAWS • RISK • UNCERTAINTY • PRECAUTIONARY APPROACH
IS IT ACTUALLY BEING APPLIED ? • IWC • CCSBT • AUSTRALIA • ICELAND • NAMIBIA • NEW ZEALAND • SOUTH AFRICA
EXTENDING THE OMP/MSE APPROACH TOWARDS ECOSYSTEM MANAGEMENT SINGLE SPECIES MULTI-SPECIES OPERATIONAL INTERACTIONS BIOLOGICAL INTERACTIONS
SOUTH AFRICAN SARDINE-ANCHOVY FISHERY OPERATIONAL INTERACTION EXAMPLE (FISH MEAL) (FISH MEAL) (HUMAN CONSUMPTION) GREATER ANCHOVY CATCH GREATER JUVENILE SARDINE BYCATCH LESS ADULT SARDINE CATCH
SARDINE-ANCHOVY CATCH TRADE-OFF AVERAGE EXPECTED CATCHES IN ‘000 TONS
MARINE MAMMAL BY-CATCH CONTROLS OPERATIONAL INTERACTION EXAMPLE • USA - “PBR” APPROACH • NEW ZEALAND - SQUID FISHERY / HOOKER SEA-LION BYCATCH
SQUID FISHERY – SEA-LION TRADE-OFF PROBABILITY FISHERY CLOSURE VS. PROBABILITY SEA-LION RECOVERY
BIOLOGICAL INTERACTION EXAMPLES FUR SEALS / HAKE MINKE WHALES / COD / HERRING / CAPELIN FUR SEALS / KRILL* NW SHELF FISHERIES • SOUTH AFRICA : • BARENTS SEA : • ANTARTICA : • AUSTRALIA: *CCAMLR - FIRST ECOSYSTEM-ORIENTATED FISHERIES CONVENTION
QUESTIONS ADDRESSED • TRADE-OFFS BETWEEN TAKES OR STATUS OF NATURAL PREDATORS AND COMMERCIAL CATCHES • DISTINGUISHING INTERACTION HYPOTHESES VIA ADAPTIVE EXPERIMENTAL MANAGEMENT
IS IT BEING APPLIED ? OMP/MSE APPROACH IN AN ECOSYSTEM CONTEXT OPERATIONAL INTERACTIONS YES • PBR FOR MARINE MAMMAL BYCATCH • SARDINE-ANCHOVY
IS IT BEING APPLIED ? OMP/MSE APPROACH IN AN ECOSYSTEM CONTEXT BIOLOGICAL INTERACTIONS (AUSTRALIAN NW SHELF EXCEPTED) NOT REALLY WHAT’S THE PROBLEM ? TENTATIVE / IMPRECISE RESULTS AD HOC BASIS FOR CCAMLR KRILL HARVEST CONTROL LAWS
REASONS FOR THE PROBLEM • LIMITED FEEDING DATA • POOR UNDERSTANDING OF HOW COMPETITION OPERATES • DISTINGUISHING MODELS WITH DIFFERENT IMPLICATIONS MORE MINKE WHALES LESS COD LESS COD, LESS HERRING MORE HERRING ?? HERRING: INCREASE/DECREASE ??
FUTURE PROSPECTS OPERATIONAL INTERACTIONS (ESSENTIALLY BYCATCH) GOOD
FUTURE PROSPECTS BIOLOGICAL INTERACTIONS SOME TIME OFF STILL (FOR ADEQUATE PREDICTIVE ABILITY) LIKELY EARLIER FOR TOP PREDATORS
BIOLOGICAL INTERACTIONS NEED TO KNOW BETTER HOW DO PREDATOR DIETS CHANGE AS PREY SPECIES ABUNDANCE ALTERS? INTERIM APPROACH MIMIC IN SINGLE SPECIES APPROACHES BY CONSIDERING TEMPORAL CHANGES IN STOCK DYNAMICS PARAMETERS
BIOLOGICAL INTERACTIONS THE BOTTOM LINE WE’RE GETTING THERE BUT WE NEED TO MOVE FASTER WHY ? WORLD FISH SUPPLY / DEMAND TRENDS