海洋保护区.pdf

Marine reserves. A bio-economic model with asymmetric density dependent migration by Claire W. Armstrong and Anders Skonhoft Working Paper Series in Economics and Management No. 04/04, October 2004 Department of Economics and Management Norwegian College of Fishery Science University of Tromsø Norway Marine reserves. A bio-economic model with asymmetric density dependent migration by Claire W. ARMSTRONG Associate Professor Department of Economics and Management Norwegian College of Fishery Science University of Tromsø N-9037 Tromsø Norway clairea@nfh.uit.no and Anders Skonhoft Professor Department of Economics Norwegian University of Science and Technology N-7491 Dragvoll-Trondheim Norway Anders.Skonhoft@SVT.NTNU.NO Abstract A static bioeconomic model of a marine reserve is introduced, allowing asymmetric density dependent migration between the reserve and the fishable area. This allows for habitat or ecosystem differences within and outside a reserve not described in earlier studies. Four scenarios are studied; a) maximum harvest, b) maximum current profit, c) open access and d) maximum sustainable yield (MSY) in the reserve. These are all analysed within the Induced Sustainable Yield Function (ISYF), giving the relationship between the fish abundance inside the reserve and the harvesting taking place outside. A numerical analysis shows that management focus on ensuring MSY within the reserve under the assumption of symmetric migration may be negative from an economic point of view, when the area outside the reserve is detrimental compared to the reserve. Furthermore, choice of management option may also have negative consequences for long run res