Date of Award

12-2002

Level of Access

Open-Access Thesis

Degree Name

Master of Science (MS)

Department

Marine Policy

Advisor

James A. Wilson

Second Committee Member

James M. Acheson

Third Committee Member

Robert S. Steneck

Abstract

In recent years there has been increasing interest in the potential of no-take marine reserves to benefit fisheries management. Scientific reviews have shown that reserves often lead to substantial increases in the density, biomass, size and diversity of marine fishes inside their boundaries. However, little empirical work has been done to determine the effect of reserves on the fisheries outside their boundaries, such as potential changes in yield, size of fleet, or variability in catch. In order to explore the interaction between the biological growth and dispersion processes of the harvested stock and the changing economic incentives of harvesters created by reserves over space and time, many researchers have turned to a modeling approach. Models are being used to construct the framework that will inform the policy decisions of how and when marine reserves are used for fisheries management. This thesis examines the information provided by these models and describes an original model developed in order to examine the effect of the management regime in place before reserve formation and outside its boundaries in a multiple species fishery. Chapter 1 provides a review of the existing reserve models that have been developed to address questions related to the potential impacts of the creation of a marine reserve on fin fish fisheries. It describes the variation in these models in terms of their construction, their biological and economic assumptions, and the specific questions they were designed to explore. It provides a summary of the conclusions that have been drawn to date with regard to the effect of reserves on modeled populations, and indicates some elements of the problem the traditional modeling approach has overlooked. Chapter 2 describes an original multiple species bioeconomic model designed to explore the effect of reserve creation on fisheries for five species with different life history characteristics, under different biological and economic assumptions. Chapter 3 provides information on the tests that were run to ensure that the model conformed to expectations based on basic biological and economic theory. It also presents the results generated with the model for different species under different management regimes. Unlike earlier models, we find that benefits from a reserve can accrue under optimal "sole owner" management. Our model also illustrates that the creation of a reserves will affect different species very differently, depending on parameters such as the amount of larval drift and adult spillover, as well as the management regime. Finally, it confirms results from an earlier model that reserves are likely to be useful in reducing year to year catch variability.

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