August 1, 2018

Blue crab population in US' biggest estuary down almost 18% this year

The blue crab population in Chesapeake Bay decreased almost 18% to 372 million this year from 455 million in 2017. This is according to the 2018 Chesapeake Bay Blue Crab Advisory Report released by the Chesapeake Bay Programme. Chesapeake Bay is the largest estuary in the US, encompassing the states of Maryland and Virginia.

The report said that while the number was below the long-term average, no overfishing has occurred.

Moreover, the blue crab population in Chesapeake Bay is not depleted, based on the "exploitation fraction" in 2017. Exploitation fraction refers to the percentage of female crabs (ages 0+) removed by fishing. Exploitation fraction in 2017 was approximately 21%, which is below the target of 25.5% and the threshold of 34%.

According to the report, blue crab commercial harvest dropped slightly in 2017. The three Chesapeake Bay management jurisdictions (Maryland, Virginia and the Potomac River Fisheries Commission) implemented additional commercial harvest restrictions during the second half of 2017 in response to the poor number of age 0 crabs (less than 60 mm or 2.4 inches carapace width).

The 2017 commercial harvest for both males and females from the Bay and its tributaries was estimated at 29.5 million pounds in Maryland, 21.7 million pounds in Virginia and 3 million pounds in the Potomac River.

The number of age 0 crabs was estimated at 167 million in 2018.

The report, which provides scientific analysis of the Bay's blue crab population, is meant to help Bay resource managers set blue crab fishing regulations.