Crabs and the Academy

Since 1968, scientists at the Academy of Natural Sciences Estuarine Research Center, or ERC, have been surveying the blue crab population of the Chesapeake Bay.

Six times a month, from June to November, the ERC boat Callinectes, crewed by George Abbe and an assistant, heads out to collect crabs in the Bay. The boat is named for Callinectes sapidus, the scientific name of the blue crab.

They maintain three lines of traps strategically placed in different parts of the bay. Each trap is emptied. The crabs are sorted, male and female; weighed; and measured across the lateral spines. Data are recorded in the field. The traps are then re-baited and re-set.

Click on the image below to hear about the importance of the Academy's crab research.

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The scientists return to the ERC lab with a subsample of their catch to be measured again and weighed individually, a procedure not practical in a moving boat.

This information is added to databases that go back some 35 years. Since 1968 more than 1200 trips have been made into the Bay to fish 22,000 pots, which have yielded more than 128,000 crabs.

From this it can be seen that "doing science" is often a long and repetitive process of gathering large masses of raw data, but this is vital so that valid findings can be reached.

The long-term decrease of size in male crabs detected in this study has led to an increase in minimum legal size for all hard-shell crabs from 5 inches to 5¼ inches, effective August 1, 2002.