Horseshoe Crab Update

Cape May hosted a panel on red knot and horseshoe crab managment last week.

Roy Miller, fisheries administrator with the Delaware Division of Fish and Wildlife, Department of Natural Resources and Environmental Control, said since 1989, his agency has used a 30-foot bottom trawl in Delaware Bay on a monthly basis to monitor the adult and juvenile horseshoe crab population. Horseshoe crabs are tagged and their migration studied.

Beginning in 1998 when management of horseshoe crabs began, Delaware’s harvest quota was 482,000 crabs. It was subsequently been lowered to 362,000, 150,000 and 100,000 horseshoe crabs, said Miller.

He said there was a considerable build up of crabs in their trawl survey in 2004 and then a decrease in 2006 and 2007. There was a considerable decline in population from 1990 to mid 1990’s.

A trawl survey by Virginia Tech, which works the ocean area just outside Delaware Bay, found a positive trend in the horseshoe crab population.

Miller said red knots declined through 2003 with some recent stabilization of the population at a relatively low level in the 12,000 to 15,000 range from both sides of Delaware Bay.

In Delaware, a harvest of just male horseshoes crabs is permitted only after June 8 of the year to allow shorebirds undisturbed access to crab eggs. Female horseshoe crabs cannot be harvested at any time, said Miller.
The maximum harvest in Delaware is 100,000 crabs per year, he said.

The conference website is here.

It is hard to say what all that means at this point. Even if it has stabilized (and I hope it has!), the red knot population is still very small and thus extremely vulnerable. I hope that the positive reports are not premature.