Millions of horseshoe crabs spawn on the shores of the Delaware Bay every spring in what is considered to be one of New Jersey’s most unique and spectacular natural phenomena.

But some conservationists worry that over-harvesting and rising sea levels could threaten the crabs – and COVID-19 is playing a role in this worry.

Any COVID-19 vaccine that will be developed will require massive amounts of horseshoe crab blood to produce. The crabs’ blue blood contains an agent used to test pharmaceuticals for dangerous bacteria called endotoxins. The crabs are bled and returned to the wild. The blood is crucial to the medical community.

Groups like the NJ Audubon estimate that 30% of horseshoe crabs do not survive once they are returned to the wild. Any more harvesting could further threaten the crab population, which is already struggling. Birds also depend on horseshoe crab eggs as a crucial food source.

“So, the Delaware Bay is one of the four most important places in the world for migratory shorebirds,” says NJ Audubon president Eric Stiles. “This is our Serengeti.”

The massively increased demand for the crabs’ blood could present a new threat to the ecosystem. Environmentalists are hoping that the medical industry would switch to a synthetic alternative to crab blood. This seemed likely until May when a powerful industry group named US Pharmacopeia said that the synthetic blood needs more rigorous testing and procedures if it is going to be used.

Stiles says that conservationists couldn’t believe it and do not understand the decisions.

“This is sheer science. When you look at the huge potential need for rapidly increasing the use of horseshoe crab blood, which we support for vaccines, and you know, plasma treatments and all sorts of things to test for purity. And you have this synthetic alternative that’s shelf-ready, according to [pharmaceutical company] Eli Lilly, it’s actually more precise than the natural blood because it’s manufactured with great consistency. It doesn’t cost them any more money and can literally save species from extinction,” says Stiles.

NJ Audubon and other groups have launched a new campaign along with business groups to get the synthetic tests approved to hopefully ensure the continuation of the horseshoe crab population.

News 12 New Jersey reached out to US Pharmacopeia for comment, but did not hear back.