2015 Chesapeake Bay Blue Crab Winter Dredge Survey

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The Maryland Department of Natural Resources (DNR) recently announced results of the 2015 Blue Crab Winter Dredge Survey results.

The abundance of spawning-age females was 101 million, substantially higher than 2014 when adult females were considered depleted. The number of adult females remains well below the peak abundances observed in 2010 and 2011 and below the established target level of 215 million crabs.

Juvenile crabs increased 35 percent from 2014, and more than doubled from the record low in 2013. The 2015 juvenile abundance of 269 million crabs is just above the 26 year average of 261 million.

The total abundance of crabs was approximately 411 million.

According to MD DNR, 19 percent of adult crabs perished in the cold temperatures this past winter. A variety of environmental factors contribute to crab abundance, including winter temperatures, coastal currents, weather patterns, and natural predators.

In May, the NOAA Chesapeake Bay Stock Assessment Committee (CBSAC) will conduct a complete examination of the blue crab data including dredge survey results and complete 2014 harvest information.

The results of this analysis will be presented in the 2015 Blue Crab Advisory Report due out in early summer. Maryland officials will evaluate the results of the report, review input from stakeholders and work with partners for the long-term health of the species.

DNR and the Virginia Institute of Marine Science have conducted the primary assessment of the Bay’s blue crab population annually since 1990. The survey employs crab dredges to sample at 1,500 sites throughout the Chesapeake Bay from December through March.

Sampling during winter, when blue crabs are usually buried in the mud and stationary, allows scientists to develop, with good precision, estimates of the number of crabs present in the Bay.

Complete survey results are available at http://dnr2.maryland.gov/fisheries/Pages/blue-crab/dredge.aspx.

source: Maryland Department of Natural Resources

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