Extensive commercial fisheries began before Glacier Bay National Monument was established in 1925. These fisheries continue today even though they are illegal under National Park Service (NPS) 1983 regulations prohibiting commercial fishing in all Parks. Glacier Bay was designated a National Park by the Alaska National Interest Lands Conservation Act of 1980 (ANILCA), which further designated certain areas of the Park as wilderness waters, including portions of the traditional commercial fishing grounds. Commercial fishing continues in these wilderness areas despite its prohibition by the Wilderness Act of 1964. Recent increases in Dungeness crab harvests in southeastern Alaska have resulted in the capture of a large proportion of the legal stock (Koeneman 1985). High exploitation rates coupled with reductions in escapement under the sex and size regulations presently in force may result in a decrease in the maximum size of males in the population toward the legal size limit. Release from human exploitation by closure of the fishery should, over time, result in a shift in the crab population to larger males. Until recently Pacific halibut were assumed to move with enough frequency that depleted areas would be replenished quickly. New data from sonic tagging studies and harvest tag studies in Glacier Bay have demonstrated that Pacific halibut have much smaller home ranges than previously thought. These new data suggest that the yearly commercial and sport harvests may take a large percentage of the local population and that these removals may affect the age and sex frequency distributions of the local population and may alter spatial density patterns. Controlled experiments testing the impact of human exploitation on the population structure of harvested marine species are rare. We propose to utilize the sequential fisheries closures proposed by NPS management as an experimental study to measure the effects of fishing on Dungeness crab and Pacific halibut population size and structure and catch per unit effort (CPUE). Hypotheses will be tested by comparing population parameters and CPUE among open and closed study sites. The pre-closure studies are essential as they will provide baseline information that will be critical for interpreting the results of the post-closure studies. Preclosure studies will consist of measurements of population size frequency, distribution, catch-per-unit-effort and absolute abundance, as well as the determination of habitat correlates, movement patterns, and ecological relationships (i.e., diet and community structure).

• Movement patterns of Pacific halibut in Glacier Bay.
• Population dynamics and habitat selection of Pacific halibut in Glacier Bay.
• Diet of Pacific halibut.