A horseshoe crab is tagged to monitor its migration pattern in the Raritan Bay. COURTESY OF JOE REYNOLDS A local environmental group is campaigning against the harvesting of horseshoe crabs due to a significant decrease in the population of the crustacean in the Raritan Bay.
After five years of monitoring the crab population, the Bayshore Regional Watershed Council has found that the number of female horseshoe crabs is significantly lower than that of males.
“For every one female, we get 10 to 15 males — and we finally figured out why,” Joseph Reynolds, co-chairman of the watershed council, said at the Jan. 9 meeting of the environmental group.
Reynolds explained that, in New York waters, female horseshoe crabs may be trapped and used as bait to attract fish.
“In 2014, one of our campaigns is to put a moratorium in New York on harvesting horseshoe crabs, especially females.”
According to Reynolds, approximately 130,000 horseshoe crabs were taken from local waters last year.
“Anybody can go to New York and you could pick up five horseshoe crabs per day, chop them up and use them to bait. You don’t need a license or a permit,” he said. “That is crazy. That is the reason why our populations are small.”
The harvesting of the crabs is illegal in New Jersey, and there is a ban on harvesting female crabs in Delaware, he said, adding that the group will reach out to local organizations to enlist support for the campaign. Reynolds explained that horseshoe crab eggs are an important food source for migratory birds that stop in the Bayshore on the way north from South America.
The birds feed on the eggs as they continue on their journey north to northern Canada to begin the next generation of migratory birds, he said. According to Reynolds, the juvenile horseshoe crabs are also an important food source for many fish species, including flounder.
For the past five years, the Bayshore Regional Watershed Council has monitored five locations along the Bayshore, where the crabs gravitate during mating season.
The council visits Sandy Hook’s Plum Island, Middletown’s public beach in Leonardo, Cliffwood Beach in Aberdeen, Conaskonk Point in Union Beach, and the mouth of the ManyMind Creek in Atlantic Highlands.
During May and June, horseshoe crabs wash up on these shores during full-moon and new-moon cycles for the annual mating season.
This is when the counting and tagging of the crabs takes place to provide information on the numbers and movements of the horseshoe crabs in local waters.
“For an animal that has been around for more than 350 million years, there is still a lot of mystery on where it goes to mate and how many crabs exist in the bay,” Reynolds said.
That information is then sent to the New Jersey Department of Environmental Protection (DEP). The tagging process involves attaching a tag to the crabs to monitor migration patterns.
Reynolds said that in 2013, approximately 400 crabs were tagged and information about their whereabouts was recently released by the DEP Department of Fish and Wildlife.
“Most of our tags were found in this area,” he said. “Our theory holds that crab activity stays in the bay.”
Reynolds said that while the crabs stay in the same area, there is movement to different beaches.
“One year they may go to Sandy Hook or Cliffwood Beach, but they don’t move to different regions,” he said.
“This tells me more about the tides and currents of the ocean than it does about the movements of the horseshoe crab.”
Bayshore Regional Watershed Council members and volunteers will monitor and tag horseshoe crabs at 9 p.m. May 15, 8:30 p.m. May 28, 9 p.m. June 13 and 8:30 p.m. June 27.