Clark spoke last Thursday evening in a talk called "The Economics of Renewable Resources: An Introduction," directed toward general audiences. His Friday talk, "The Worldwide Crisis in Fisheries: The Use and Misuse of Models," was a more technical discussion of the use of mathematical economic models in the management of ocean fisheries.
To begin his presentation, Clark spoke about the North Atlantic cod collapse. The northern cod fishery became the most intensively managed fishery in the world after Canada took it over in 1977.
Then, in 1991, the fishery collapsed without warning. A moratorium on cod fishing was put in place a year later and is still in effect.
"More than anything, this one collapse has triggered scientists to re-evaluate their worldview of how fisheries ought to be managed," Clark said.
He showed a bio-economical model to illustrate how over-regulation of fisheries results in over-fishing, lower fish values and impoverished fishermen.
He then discussed the traditional approach to managing fisheries. The government usually hires a body of scientists who choose a model of population dynamics, estimate the model, determine the optimal spawning strategy for the fish, set a total allowable catch (TAC) quota for the year, monitor the catch and close the fishery when the TAC has been caught. Many different types of fisheries use this method, Clark said.
What the traditional method ignores, he continued, is fish behavior, fishermen behavior, economics, ecosystems and possible errors.
Clark then showed an individual behavior model to discuss unregulated open-access fishing, during which fleets continue fishing. In these scenarios, the fish stock is reduced, the stock reaches bio-economical equilibrium and the fishermen quit for the rest of the year.
Over-fishing and an over-capacity of fishing fleets are the two components of what Clark called the global crisis. Most fish stocks were at one time over-fished, and many still are, he said.
Clark invented the TAC-based model to show the effects of fishery management. TAC-based management leads to a shortened fishing season, low economic benefits, over-capacity of fishing fleets and pressure for high TACs.
To achieve optimal sustainability, he discussed not letting "just anyone go out and fish" but issuing fishing licenses, and using a buy-back program for people who already own licenses. However, Clark did not suggest using buy-back programs, which he said "[are] always certain to make the situation worse."
Economists recommend that each fishery use an Individual Transferable Quota (ITQ) system, which gives fishermen an economical incentive to cooperate with other fishermen and maximize the value of the quota. ITQ systems are now used in Iceland, Norway, Namibia, Australia, New Zealand, Canada and limited areas of the United States.
Approximately 50 people attended the hour-long talk. Chloe Stull-Lane 07 was impressed with the lecture. She said, "Colin Clarks talk built important bridges between economics, biology and environmental studies, proving insight into how we, as St. Olaf students, Americans and citizens of the world, can prepare for a sustainable future."