On the economic optimality of marine reserves when fishing damages habitat

• Main Author: Moeller, Holly Villacorta
• Other Authors: Michael G. Neubert.
• Format: Others
• Language: English
• Published: Massachusetts Institute of Technology 2010
• Subjects: Joint Program in Biological Oceanography.; Biology.; Woods Hole Oceanographic Institution.
• Online Access: http://hdl.handle.net/1721.1/57574

Thesis (S.M.)--Joint Program in Biological Oceanography (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 2010. === This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. === Cataloged from student submitted PDF version of thesis. === Includes bibliographical references (p. 125-127). === In this thesis, I expand a spatially-explicit bioeconomic fishery model to include the negative effects of fishing effort on habitat quality. I consider two forms of effort driven habitat damage: First, fishing effort may directly increase individual mortality rates. Second, fishing effort may increase competition between individuals, thereby increasing density-dependent mortality rates. I then optimize effort distribution and fish stock density according to three management cases: (1) a sole owner, with jurisdiction over the entire fishery, who seeks to maximize profit by optimizing effort distribution; (2) a manager with limited control of effort and stock distributions, who seeks to maximize tax revenue by setting the length of a single, central reserve and a uniform tax per unit effort outside it; and (3) a manager with even more limited enforcement power, who can only set a tax per unit effort everywhere in the habitat space. I demonstrate that the economic efficiency of reserves depends upon model parameterization. In particular, reserves are most likely to increase profit (or tax revenue) when density-dependent fish mortality rates are affected. Interestingly, for large habitats that are sufficiently sensitive to density-dependent fish mortality effects, reserve networks (alternating fished and unshed areas of fixed periodicity) emerge. These results suggest that spatial forms of management which include marine reserves may enable signicant economic gains over nonspatial management strategies, in addition to the well-established conservation benefits provided by closed areas. === by Holly Villacorta Moeller. === S.M.