Independence Day is one of the last opportunities to watch the horseshoe crabs of Gravesend Bay getting busy on the beach this season.
Every year, between May and July, during full and new moons, horseshoes can be seen congregating on the beaches of Calvert Vaux Park borrowing their eggs in the sand, because of the moon’s gravitational force causes the tide to rise the highest. During the following tide, the eggs will be washed out to sea.
Horseshoe crabs, which are living 450 million year old fossils, are a critical part of an eco system that sustains federally endangered shorebirds at Calvert Vaux, according to the Parks Department. Since the critters are being harvested as bate in a growing conk and eel fishing industry, conservationists are worried about the rate horseshoes are replenishing.
Recently, it was discovered that horseshoe crab blood can react to bacteria that can cause harm to people, so biomedical researchers have been using horseshoe blood to test everything that goes into human bodies.
“If we were to let the species to go extinct right now, it would be a real problem for us,” says Kim McKown of New York State Department of Environmental Conservation.
Since horseshoe populations are shrinking, there has been a concerted effort to monitor the pattern of these amazing animals. This month, as part of the New York Horshshoe Crab Monitoring Network, researchers and volunteers hiked out Calvert Vaux and Kaiser parks at night, to collect data on horseshoe crab spawning abundance, size, sex and tag returns. Though the more trips were tentatively planned for July, the monitoring excursions were cut short, because of low counts in June.
Fortunately, the horseshoes — which are actually more closely related to scorpions and spiders than crabs — can still be spotted swimming and spawning near the bank of the park’s recently restored habitat in sets of twos and threes this weekend.
Anyone interested in witnessing this incredible event, can head out to Calvert Vaux up to two days before and two days after the July 4 new moon. There is also a chance you might catch them on the next full moon cycle, on July 19. Enjoy!