Investigating Economic Costs Of Derelict Blue Crab Callinectes Sapidus Pots And Preferred Mitigation Solutions In The Chesapeake Bay
Master of Science (M.Sc.)
Virginia Institute of Marine Science
Donna M Bilkovic
Kirk J Havens
Jeffrey D Shields
Derelict fishing gear, particularly pots or traps, occupy waters worldwide and cause negative ecological and economic impacts. Derelict pots persist throughout Chesapeake Bay, the largest estuary in the U.S., that supports a valuable commercial fishery for the blue crab Callinectes sapidus. Chesapeake Bay is responsible for 30-40% of U.S. commercial blue crab harvests. Yet, few studies have quantified the impacts of derelict pots on harvest or the perceptions of commercial fishers on derelict pot mitigation activities in this predominantly pot fishery. This thesis examined the impacts of derelict pots on harvest in a field experiment and worked with commercial fishers to develop and disseminate a mail survey that was used to quantify the preferences and decision-making of commercial fishers for addressing derelict pots. The field experiment simulated the presence of derelict pots near actively fished pots and found that derelict pots can reduce harvests by up to 30% during the summer, but not during the fall. Female capture rates were consistently lower when derelict pots were present, but male capture rates were not negatively affected. To better understand the perceptions of commercial fishers and their preferences for derelict pot mitigation actions (e.g., location and removal program, installation of identification tags on pots), a stated preference survey with a discrete choice experiment was distributed to all commercial fishers licensed to deploy hard pots in Virginia. There was a 42% response rate (430 of 1,032 fishers returned the survey packet), and most mitigation activities included in the survey were too costly for commercial fishers to willingly participate in. Management incentives (e.g., bushel limit increase, pot limit increase, season extension) alone were not enough to offset costs and encourage participation in activities that were disliked by commercial fishers. However, there was strong heterogeneity observed across the population, thus some segments of the population would be far more willing to participate in mitigation efforts than others. For instance, participants that perceived derelict pots to cause only negative impacts were 37% more willing to participate in any mitigation activity on average. Results from this study can be used to better inform resource managers and policymakers responsible for addressing the issue of derelict pots and other types of derelict fishing gear plaguing fisheries around the world.
© The Author
DelBene, James, "Investigating Economic Costs Of Derelict Blue Crab Callinectes Sapidus Pots And Preferred Mitigation Solutions In The Chesapeake Bay" (2020). Dissertations, Theses, and Masters Projects. William & Mary. Paper 1593091644.