Presentation on theme: "Human Response Ecosystem Based Management. Kinds of human response Fishing Fleets – When to fish – Where to fish – Discarding – Investment in gear – Response."— Presentation transcript:
Human Response Ecosystem Based Management
Kinds of human response Fishing Fleets – When to fish – Where to fish – Discarding – Investment in gear – Response to regulation – License movement Markets – Demand curve Managers – Feedback control Scientists
Covered today Fleet response and models Knapp’s work on license movement
The nature of fisheries – fish and people We regulate fleets The root cause of current fisheries concerns is generally regarded as “too many boats chasing too few fish” 90% of the science in fisheries goes into the fish … we need to expand our understanding and work on the other ½ of the fisheries
My own experience Peter Larkin’s lecture and the B.C. purse seine fleet – Why don’t all the boats fish whenever they can – Where do they choose to fish – What determines catching power
Dynamics of the B.C. salmon fleet Hilborn, R., and Ledbetter, M Analysis of the British- Columbia Salmon Purse-Seine Fleet - Dynamics of Movement. J. Fish. Res. Board Can. 36: Hilborn, R., and Ledbetter, M Determinants of Catching Power in the British-Columbia Salmon Purse Seine Fleet. Can. J. Fish. Aquat. Sci. 42: Hilborn, R Fleet Dynamics and Individual Variation - Why Some People Catch More Fish Than Others. Can. J. Fish. Aquat. Sci. 42: 2-13.
Canadian Drum Seiner
Johnstone Straight Juan de Fuca
Late 1970s Hollings functional and numerical responses A predator that keeps records The “ideal free distribution”
Why don’t Johnstone St. Fishermen fish in Juan de Fuca
Lab exercise basic fleet movement model
Functional and numerical response of salmon vessels
Effort, catch and CPUE in the Tasmanian lobster fishery Hilborn, R., and Kennedy, R. B Spatial Pattern in Catch Rates - a Test of Economic- Theory. Bulletin of Mathematical Biology. 54:
Abalone divers and their motivation and learning Prince, J. D., and Hilborn, R Concentration profiles and invertebrate fisheries management. pps In G. S. Jamieson and A. Campbell [ed.] North Pacific Symposium on Invertebrate Stock Assessment and Management. Can. Spec. Publ. Fish. Aquat. Sci. 125.
2 nd excel spreadsheet
Other key areas Entry/Exit Discarding Determinants of CPUE Vessel and gear investment Response to regulation
Moving to license movement Many people are concerned that when fishing licenses have economic value, the licenses tend to leave small traditional fishing communities and move to larger centers BC native salmon permits The Alaskan license data base
Gunnar Knapp stuff
Knapp’s theory Cost of fishing – Lower for local residents – Outsiders must pay airfares, boat storage Opportunity cost – Locals often have no other alternatives – Outsiders have range of other jobs Access to capital Number of potential buyers Economic motivation
A simple thought experiment Prior to limited entry, a local fisherman makes $10,000 fishing for salmon as an augmentation to subsistence hunting and fishing More economically motivated individuals, both local and from outside make $50,000 per year Limited entry is introduced: licenses become worth $200,000, because an aggressive individual can earn $50,000 per year What is the economic logic for a small scale low- end fisherman?
Ecosystem based management Humans are part of the ecosystem Humans respond to changes in the ecosystem and to regulation EBM needs to consider this response