Photo: Volunteer Sharon Morrill measures and records a horseshoe crab’s size, then puts it back.
By Patty Wight
Published on Maine Public on June 18, 2026
What has twelve legs, ten eyes and one tail? It’s not a creature from science fiction — it’s the horseshoe crab, a so-called living fossil that some scientists say is now threatened with extinction.
That’s at the center of a lawsuit alleging the federal government has so far failed to include them for protection under the Endangered Species Act.
In Maine, citizen scientists are monitoring the Atlantic horseshoe crab along the coast.
The salty ocean waters are warming along the shore in Great Salt Bay, and love is in the air.
“And there is a horseshoe crab — for lack of a better word — orgy that occurs every year at this time, where they’re mating,” says Sharon Morrill, a volunteer with the Coastal Rivers Conservation Trust in Damariscotta.
Morrill is part of a small group that monitors horseshoe crabs at two sites every day at high tide during their spawning season, from mid-April to mid-June.
Today, she’s joined by her sister Lynn Bernier, who’s also a volunteer. They’re both dressed in waders, and the rounded toe of their boots is not unlike the shape of a horseshoe crab, which looks like an upside-down bowl with a tail.
When Morrill sees my polka dot rain boots, she issues a warning.
“You have very attractive boots on, so don’t be surprised if they think you’re female, and they’re on your boots. This happens too,” she says.
The pair make their way through tall grass to the shore, where they first measure water temperature and salinity. Horseshoe crabs — which, by the way, aren’t crabs and are closer to spiders, ticks and scorpions — prefer warm, salty water for spawning. Next, Morrill and Bernier wade through knee deep water to begin counting.
“We’ve got one single, one double, and we’re gonna walk this way,” Morrill says to Bernier, who records the data.
Morrill is careful not to disturb mating doubles. But she sees a single crab that’s dead, picks it up and turns it over.
“Now this is a male,” she says. “They have like, boxing gloves.”
It’s a pair of small, bulbous legs that males use to clasp onto females so they can fertilize the thousands of tiny eggs she’ll lay.
“Boxing gloves are so apropos. They are frisky, feisty, these males,” Morrill says.
“We’re guessing they’re teenagers or something,” Bernier says with a giggle.
Horseshoe crabs are often called living fossils. They’ve roamed the Earth since well before the dinosaurs. But some scientists say they’re now threatened with extinction.
