Horseshoe crabs are killed for bait by commercial fishermen.

Horseshoe crabs are killed for bait by commercial fishermen. Credit: Universal Images Group via Getty Images/REDA&CO

This guest essay reflects the views of Carl Safina, endowed professor for nature and humanity at Stony Brook University.

Plenty of people have never seen a horseshoe crab. Of those who have, plenty are scared of them. But their sharp tail, or “telson,” is not a stinger and not even a weapon; it serves only to let upside-down horseshoe crabs turn themselves right side up. No need to fear them. They haven’t hurt a person during their 450 million years of existence.

But horseshoe crabs have much to fear from us. They’re killed for bait by commercial fishermen, who easily catch them by yanking them off their nests as they are laying their hundreds of eggs along quiet moonlit shores. The scent of their eggs draws eels and whelks to the traps.

The state Department of Environmental Conservation allows fishermen to take 150,000 crabs annually. Since 2000, more than 4 million horseshoe crabs have been killed in Long Island waters alone. Increased protections in neighboring states like Connecticut have put more pressure on horseshoe crabs in New York’s tidal waters.

There is also the odd business of bleeding them for an important but soon-to-be outmoded medical purpose. Horseshoe crabs’ turquoise, copper-based blood contains a clotting agent that is extremely sensitive to bacteria that cause infections, clotting in their presence. Horseshoe crab blood is used to screen batches of injectable drugs and implantable products such as knee and hip replacement joints to make sure they’re bacteria free. Unfortunately, a hefty fraction of the horseshoe crabs (about 15-20%) die in the process of being bled. Thankfully, this is becoming unnecessary; a synthetically manufactured alternative known as rFC is widely used in Europe (horseshoe crabs don’t live there) and was recently approved for use in the United States and in Asian countries.

After decades of abuse, once-abundant horseshoe crabs have declined drastically. This is an issue for more than horseshoe crabs because their little protein-rich eggs (each much smaller than a pea) are vital food for at least a dozen shorebirds, including ruddy turnstones, semipalmated sandpipers, and the federally threatened red knot. Loggerhead turtles, a federally endangered species, prey on the adults.

Our one-way abusive relationship with horseshoe crabs will change if Gov. Kathy Hochul signs into law a bill the State Legislature passed earlier this year. The bill bans the commercial taking of horseshoe crabs in New York state waters, whether for bait or blood, requiring baymen to use other available types of bait.

Horseshoe crabs, which are more closely related to spiders than to true crabs, have been around more than 2,000 times longer than people have been around. Their 10 eyes, including two compound eyes with up to 1,000 photoreceptors, led to an early understanding of how animals see. Horseshoe crabs molt as many as 18 times during their 25-year lives as they grow from tiny crabs to dinner-plate-size animals. Many of the “dead” horseshoe crabs on beaches are cast-off shells. If they’re tan in color and there’s an open seam along the front, it’s a shell the crab outgrew and left for you.

With the manufacture of rFC and the legislation to stop the commercial crab-grab awaiting the governor’s action, we have a chance to write a new chapter of peaceful coexistence with horseshoe crabs, one that no longer views crabs as merely a commodity to be used and abused. If you’d like to help protect horseshoe crabs, write, call or email Gov. Hochul and ask her to sign this important legislation.

This guest essay reflects the views of Carl Safina, endowed professor for nature and humanity at Stony Brook University.