A world expert on horseshoe crabs is worried about their extinction after 455 million years of life on Earth — largely because the crab has become a delicacy in some Asian nations.
Suffolk County resident John T. Tanacredi, an educator and researcher, first became familiar with horseshoe crabs as a boy from Brooklyn spending summers in Babylon and learning to swim off a beach along the Great South Bay. In those days, the early 1960s, the beach was “filled” with horseshoe crabs, he remembered. The shores of Shelter Island as well as the rest of Long Island, and the wetlands they embrace, have been an active habitat for horseshoe crabs.
As a young man, Mr. Tanacredi, volunteering as a docent at the New York Aquarium in Coney Island, began studying what he speaks of as this “alien-looking creature.” Mr. Tanacredi noted the impact on him of the writings of the aquarium’s director, George Ruggieri, who was also a Franciscan priest. Mr. Ruggieri’s writings told of how horseshoe crabs, beyond being an extraordinary life form in themselves, are “living fossils”Mr. Tanacredi said, and have provided “pharmaceuticals from the sea.”
The blue blood of the horseshoe crab is indispensable in the detection of bacterial endotoxins in medical applications. The crabs are widely harvested for this medical purpose, producing a $300 million global industry. The animals are bled, the blood collected and most of the crabs survive upon being returned to the sea.
Horseshoe crabs, despite their name, are not crabs but more closely related to spiders and scorpions. Their smooth, hard shell is shaped like a horseshoe, thus their name. They predate the dinosaurs by more than 200 million years.
For years horseshoe crabs were killed on a massive scale to make fertilizer. And they are still taken to be used as bait, especially to catch eels and whelk or conch. Some states forbid or restrict the taking of horseshoe crabs. In New York, the Department of Environmental Conservation has been setting yearly quotas, allowing 150,000 to be taken this year. Can that number be appreciably lowered?
“Habitat loss and habitat degradation,” Mr. Tanacredi said, have been negatively affecting horseshoe crabs. Shoreline development has had a major affect. “They go to the same beach every year to mate,” he noted.
And now horseshoe crabs have become “an exotic food” in parts of Asia. Eating them has become especially popular in Singapore, Vietnam and Cambodia, and this is exacerbating the survival of the horseshoe crab as never before.
“In a decade, they could be extinct,” Mr. Tanacredi said.
“Extinction,” he added, can “happen all of a sudden.” He spoke of the passenger pigeon, of which there were an estimated three billion in the world in the 19th century. They were heavily hunted, and in 1914, the last one, named Martha, died in her cage at the Cincinnati Zoo.
Mr. Tanacredi, a Melville resident, has been director of the Center for Environmental Research and Coastal Oceans Monitoring (CERCOM) of Molloy College since 2013. The center is located at what had been the Blue Point Oyster Hatchery in West Sayville. At CERCOM, “about 10,000 juvenile horseshoe crabs” are produced each year.
Mr. Tanacredi is a full professor at Molloy, teaching courses that include Ecology and Marine Biology. Before that, for 13 years, he was a professor and chairman of the Earth Marine Sciences Department at Dowling College in Oakdale, which this year closed. Dowling underwent extinction itself.
Earlier, for 24 years Mr. Tanacredi was a coastal research supervisory ecologist for the National Park Service. He also worked for the U.S. Coast Guard. And he served as a “hurricane hunter” for the U.S. Navy and in that job “cut my teeth on the impacts of hurricanes on coastal environments.” For 12 years he was deputy director of the Aquatic Research and Environmental Assessment Center at Brooklyn College. And he has been chairman of the New York Marine Sciences Consortium and also the Suffolk County Wetlands Management Work Group.
He holds a doctorate in environmental health engineering from NYU-Polytechnic Institute and has had 50 peer-reviewed scientific papers published and has authored five books.
Horseshoe crabs “survived five mass extinction events” that have occurred on the earth through their 455 million years of existence, Mr. Tanacredi said. “They are a wonderful organism. They are so important to human health — and this would be lost forever, too. It is sad testimony to how we treat other species on this planet.”