Bioeconomics of seasonality, seasonal stock depletion and marine mammal protection

Kathryn D Bisack, University of Rhode Island


This research investigates seasonality, stock depletion and the protection of marine mammals using bioeconomic analysis. Seasonality reflects the availability of a renewable resource during different times of the year, and stock depletion refers to the removal rate of a renewable resource. The effects of these two components are explored under open access, optimal exploitation and individual transferable quota (ITQ) systems. ^ This dissertation is composed of three manuscripts. The first manuscript develops a theoretical model that explores seasonality and seasonal stock depletion within a single species, single fleet, and single fishery under open access conditions with constant and variable price. It is then expanded to a multifleet, multi-species scenario. Optimal exploitation and individual transferable quota (ITQs) are then investigated under seasonality and stock effects. ^ In the second manuscript, an estimate of the efficiency losses due to stock depletion during the course of the year in the New Zealand southern scallop fishery is made, which has been under ITQ management since 1992. A “race-to-fish” behavior is observed in the southern New Zealand scallop fishery. The analysis shows that if there is a lame stock depletion ITQs are not optimal. If the stock depletion is negligible, ITQs are optimal. Theoretical and empirical results of the first two manuscripts show ITQs are sub-optimal to the optimal exploitation model when there is a seasonal stock depletion. ^ Finally in the third manuscript, the biological and economic consequences of season area closures are compared to marine mammal ITQs. The results of a case study of the New England sink gillnet fishery show, ITQs for marine mammals are economically more efficient than season area closures in reducing the total harbor porpoise take. Profits under ITQs are 2–16% greater than closures. Effort and profit reductions under ITQ management are spread more evenly across seasons and ports compared to closure management. ^

Subject Area

Economics, Agricultural|Environmental Sciences|Agriculture, Fisheries and Aquaculture

Recommended Citation

Kathryn D Bisack, "Bioeconomics of seasonality, seasonal stock depletion and marine mammal protection" (2000). Dissertations and Master's Theses (Campus Access). Paper AAI9988721.