The Chesapeake Bay Blue Crab (Callinectes sapidus): A Multidisciplinary Approach to Responsible Stock Replenishment

Abstract

The Chesapeake Bay has traditionally been one of North America's most productive fishing grounds, supporting the world's largest blue crab fishery. During the last several decades, fishing mortality and environmental degradation led to ∼ 70% drop in the bay's blue crab abundance, 84% decline in its spawning stock, and historically low levels of juvenile recruitment as well as nursery habitats being below carrying capacity. This situation makes the Chesapeake Bay blue crab an appropriate candidate for responsible stock enhancement. A multidisciplinary, multi-institutional program was developed to study the basic biology and life cycle of the blue crab, develop hatchery and nursery technologies for mass production of blue crab juveniles, and assess the potential of using cultured juveniles to enhance blue crab breeding stocks and, in turn, bay-wide abundance and harvests. Basic biology and culture studies enabled closing the life cycle of the blue crab in captivity. Juvenile crabs have been produced year round, with excellent survival. During 2002–2006, over 290,000 cultured crabs were tagged and experimentally released into the bay's nursery habitats. Cultured crabs survived as well as their wild counterparts, increased local populations at release sites by 50–250%, grew quickly to sexual maturity, mated, and migrated from the release sites to spawning grounds, contributing to the breeding stock as soon as 5 to 6 months post-release. Findings reported in this text and other articles in this volume are indicative of the feasibility of our approach of using hatchery juveniles to replenish the blue crab breeding stocks in the Chesapeake Bay.

Keywords:

• breeding stock restoration
• hatchery
• tag and recapture
• release strategies
• stock enhancement

ACKNOWLEDGEMENTS

The Blue Crab Advanced Research Consortium and its extensive studies would not have been possible without the vision and continuous support of U.S. Senator Barbara Mikulski. The partnership and cooperation of the Maryland Watermen's Association, especially its president, Larry Simns, and Mick Blackistone, Executive Director of Crab Restoration Around the Bay, is highly appreciated. We are grateful to Steve Phillips, Chief Executive Office, Phillips Foods Inc., for his financial and moral support. We are also thankful to the staff of the Maryland Department of Natural Resources for allowing us to use their facilities. This research was supported by a NOAA Chesapeake Bay Program Grant (NA17FU2841) to the Blue Crab Advanced Research Consortium.

Authors' Note: Since the submission of this manuscript, the total number of released hatchery crabs has increased significantly. A total of 215,000 hatcheryraised crabs were released into Chesapeake tributaries in 2007, bringing the 2001-2007 cumulative release total to 515,000 juvenile hatchery crabs.