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Applying CPUE as management tool a discussion. CPUE as management tool. Outline. Introduction Context of CPUE Merit of CPUE indicators CPUE and the Dutch beam trawl Debate topics. CPUE as management tool. Introduction. C = f q B (1) U = C/f (2)
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CPUE as management tool Outline • Introduction • Context of CPUE • Merit of CPUE indicators • CPUE and the Dutch beam trawl • Debate topics
CPUE as management tool Introduction • C = f q B (1) • U = C/f (2) • U = q B (3) • C t/f t= α(C t+1/f t+1) (4) • q tN t = α (q t+1N t+1)(5)
CPUE as management tool Context of CPUE • Different CPUE measures • Catch: Kg, $ • Effort: Hp, seadays, $ • Stock — CPUE • CPUE > minimum • insight CPUE development
CPUE as management tool Merit of CPUE indicators • Catch in kg • Proceeds in monetary terms • Hp-days • Costs per time unit • Energy usage per unit of time
CPUE as management tool • CPUE and the Dutch beam trawl fisheries
CPUE as management tool CPUE and the Dutch beam trawl fisheries • Correlation coefficient between selected CPUE measures and stock levels
CPUE as management tool Debate topics • Relationship CPUE — Stock • Simple indicator • Time aspect CPUEt , Stockt-1, sole , Stockt-2, plaice , • Multi-species fisheries • Catchability coefficient q • Effort allocation Conclusions Issues
CPUE as management tool Closing remarks • CPUE is a relative simple indicator which can be established ‘above the water’. With modern technology monitoring in ‘real time’ could be established. • By using CPUE the motivation for underreporting catches and manipulating catch declarations is reduced. • The information is derived from the commercial fleet itself which enhances the dialogue between the industry and the policymakers.