human response ecosystem based management. kinds of human response fishing fleets – when to fish...

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. 1979. Analysis of the British-Columbia Salmon Purse-Seine Fleet - Dynamics of Movement. J. Fish. Res. Board Can. 36: 384-391.

Hilborn, R., and Ledbetter, M. 1985. Determinants of Catching Power in the British-Columbia Salmon Purse Seine Fleet. Can. J. Fish. Aquat. Sci. 42: 51-56.

Hilborn, R. 1985. 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. 1992. Spatial Pattern in Catch Rates - a Test of Economic-Theory. Bulletin of Mathematical Biology. 54: 263-273.

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Abalone divers and their motivation and learning

Prince, J. D., and Hilborn, R. 1998. Concentration profiles and invertebrate fisheries management. pps. 187-196. In G. S. Jamieson and A. Campbell [ed.] North Pacific Symposium on Invertebrate Stock Assessment and Management. Can. Spec. Publ. Fish. Aquat. Sci. 125.

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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