BERLIN – Officials with the Maryland Department of Natural Resources (DNR) are asking for the public’s help to ensure the survival of horseshoe crabs this season.
In the coming weeks, visitors to Maryland’s coastal bays and beaches can witness horseshoe crabs as they migrate from the depths of the Atlantic Ocean to the shoreline to spawn.
The greatest number of horseshoe crabs can be found on Maryland beaches during the full moon, May 29 and June 28, and new moon, June 13 and July 12.
Steve Doctor, a DNR biologist, said the annual spawning run brings in thousands of horseshoe crabs.
“The horseshoe crab is such a unique species here in Maryland,” he said. “During peak egg-laying times, the horseshoe crabs are so abundant you can’t even see the sand.”
Doctor noted horseshoe crabs use high and low tides during its annual spawning process. During new and full moons, for example, horseshoe crabs come to coastal beaches during high tides to spawn. When the tide gets lower, the sun acts as an incubator for the remaining eggs. By the next high tide, the hatched eggs are swept out to sea.
Each year, Doctor and his team conduct an annual horseshoe crab survey – made possible through a partnership with the Maryland Coastal Bays Program – to determine the number of horseshoe crabs that come ashore.
“The survey we do is for tracking the local abundance and making sure everything is stable,” he said.
Doctor said recent surveys have found that the population of horseshoe crabs have remained relatively unchanged.
“They are in pretty good shape,” he said.
Doctor noted that those wishing to catch a glimpse of the horseshoe crabs can visit the coastal bays of Ocean City or areas around Assateague State Park. Locations such as Skimmer Island, to the north of the Route 50 bridge, have been known to attract as many as 20,000 horseshoe crabs.
One individual horseshoe crab can lay nearly 20,000 eggs, but many do not survive, according to DNR officials. Crustaceans, fish and migrating shorebirds, including the red knot, prey on the eggs for food.
“The Mid-Atlantic is a crucial byway for migratory birds,” said Public Affairs Officer Eric Wilson. “The eggs are important for a lot of them.”
Adult horseshoe crabs are also vulnerable to predators if they get stuck on their backs.
To that end, the department is asking anyone who spots a horseshoe crab on its back to gently flip the crab over, so it can return to the water. The best practice for flipping over a horseshoe crab is to pick it up by its sides using two hands; never by its telson (tail).
While the horseshoe crab may look menacing, DNR officials said they are harmless and gentle creatures that do not bite or strike.