Some residents may be aware that one of our shoreline ecosystem’s most critical species has been on a steady and concerning decline for decades: the horseshoe crab. This rather weird, alien-looking arthropod (it’s not a crustacean) is not only a critical food source for numerous marine and bird species, this creature has actually saved your life before and will only do so again if we take measures to halt their decline and reestablish its prominence in its habitat

According to Madison Conservation Commission Chair Heather Crawford, this once ubiquitous critter needs protection and help quickly as recent studies are still finding that is continues to decline regionally and numerically. These crabs are among the planet’s oldest organisms still living, have outlasted dinosaurs and survive through numerous extinctions, and are considered “living fossils.”

“People should care about horseshoe crabs for two reasons, one is ecological and the other is human health,” Crawford said. “Without horseshoe crabs, we would not have vaccines, including the COVID vaccine. The blood of horseshoe crabs is a absolutely critical component of vaccines. Almost anything you put in your body has been tested with the lysate product, which is made from their blood.”

The liquid is so precious that it costs $15,000 to $18,000 a quart, according to Crawford.

“So, this seemingly unremarkable creature is simply vital to our health. Their eggs also provide a critical source of nourishment for migratory birds, and there has been a big decline in these and other species, which has been attributed to the decline in horseshoe crabs,” said Crawford. “That is why it is so important that people recognize their worth and help protect them. The species is still in decline.”

Crawford is also involved in educational programs, including tagging efforts, that monitor the species and collect data for state departments, and she said the problem only appears to be getting worse.

“We are still only really picking up in Madison [horseshoe crabs] that are the big, old ones; we are not seeing the younger generations, which is obviously concerning. We are however, seeing repeats [tagged crabs], so that is a good sign, but overall it is still very concerning.”

According to Crawford, in late spring and early summer, horseshoe crabs arrive on area beaches en masse to lay their eggs. The peak spawning period on the Atlantic Coast is May through June.

So, what can residents do to help?

Crawford said that the best thing to do is to leave horseshoe crabs alone. Unless they look like they are obviously in distress or are on their backs, just leave them alone.

“Try and just leave them alone and don’t disturb them. If they are in an area where they seem like they are in real danger, you can move them by picking them up from the sides—they won’t bite or nip. Don’t pick them up by their tails, but make sure the tail is pointed away from you. It won’t sting, but it could scratch you,” Crawford said.

“Pick them up by their sides to move them, and then you can turn them over and hold them like a bowl, but try to limit interaction and get them flipped back over quickly,” she continued. “If you find ones on the beach, and they are buried in the sand, just leave them alone as they are probably just waiting for the next high tide to head back. One other point: Don’t take dead horseshoe crabs home. It’s tempting to collect them as a souvenir, but I can tell you, they will never stop smelling so there is no point in taking them home, and that dead crab and the nutrients are important for ecosystem, so just leave any dead ones here they are. And please, if you find one with a tag, take a picture and send it in and make sure to report it.”

A Few Fast Facts About Horseshoe Crabs

• Horseshoe crabs do not have teeth and don’t bite

• Their tail does not sting; it allows them to re-right themselves when flipped on their back, but it can scratch so be careful

• Don’t pick up horseshoe crabs by the tails—if the tails is damaged, that individual is probably doomed

• This species doesn’t reach sexual maturity until 12- to 15 years old, so protection is vital to their survival

• If you find a crab with a tag, follow any instructions on it and report your find immediately

• Habitat destruction is a main factor in their decline, but their use as bait for commercial fisherman is always having an adverse effect on the species.

• Anyone wishing to legally take horseshoe crabs for fishing needs to review the new laws concerning the dates and the limits imposed on the species. Visit the Department of Energy & Environmental Protection site portal.ct.gov/DEEP for all of the relevant info

• A fully adult female will lay 60,000 to 100,000 eggs, but only one of those will reach the age to reproduce again

• These crabs are among several species that are affected by light pollution, so turn down or turn off lights, especially anything that shines directly at or one the water.