Researchers testing for bait alternatives to horseshoe crabs to catch whelk

The future of scungilli  may rest with Matt Sclafani.

The Cornell Cooperative Extension researcher and his team are leading a new series of trials at the Stony Brook University Marine Laboratory at Flax Pond in Old Field that seek to find viable alternatives to horseshoe crabs for bait to trap channel whelk.

For decades, Long Island fishermen have used quartered sections of horseshoe crabs to bait their pots to trap whelk, also known as conch, in Long Island Sound and local bays. Fishermen say nothing they’ve tried works as well as horseshoe crabs, and some helped research to trial alternatives, including artificial baits that look like white hockey pucks and didn’t work at all. (One fisherman even said traps with no bait worked better than the artificial bait.)

Whelk have been a steady market for Long Island fishermen for decades, but the market grew in importance in the past 20 years as the Long Island Sound lobster population sharply declined. Many fishermen found they could use the same gear to harvest whelk, including special electric winches to haul the heavy traps from bay bottoms. Fishermen such as Phil Karlin, of Riverhead, in the 1980s started selling whelk to Italian restaurants as far away as Little Italy in lower Manhattan. He and his wife, Dolores, make a whelk salad they sell in their shop and at green markets in Manhattan.

The research is crucial now that Gov. Kathy Hochul has signed a state law that eventually bans the use of horseshoe crabs for bait and medical purposes, with harvesting of the crabs gradually phased out starting this year and ending with a full ban by 2029.

A 2024 federal assessment of horseshoe crabs by the Atlantic States Marine Fisheries Commission  found the New York region "continues to be in a poor state," while commercial landings in New York give mixed signals. Last year 74,078 horseshoe crabs were harvested, according to preliminary state figures, a sharp drop from the 141,000 caught in 2024, though the drop may be tied to new restrictions around the full-moon harvest, baymen say. Both figures represent sharp increases from 2020, when just over 44,000 were harvested, according to state data.

Sclafani said recent spawning surveys suggest signs of increases on the South Shore, where a ban is in effect for all of Fire Island, while Long Island Sound has seen severe declines, according to a paper in Nature. 

Sclafani, senior resource educator for Cornell Cooperative Extension, is leading a team that includes Joe Costanzo and Stephen Havens that is testing other baits in specially made tanks at the Flax Pond facility, which uses a sophisticated system of pumps to provide a constant stream of local salt water for the experiments. He’s working with Stony Brook University's Flax Pond Laboratory manager, Demetrios Caroussos.

"We’re trying to come up with another formulation for something that will be as attractive or better in attracting whelk to the traps as horseshoe crabs," Sclafani said.

The solution? A two-channel, split-stream flume tank.

It works like this: Water enters the flume tank through two separate sources at one end and passes through two canisters loaded with various baits in bags. The water then passes through a series of baffles to smooth out the flow so that a whelk, waiting in a holding tank near the end of the device, can get a good, even scent of both.

One canister at the end of the long troughlike tank will contain sections of horseshoe crab, the other one of five separate test baits — hard clams, razor clams, green crab, scallop-body waste and other fish waste. A camera fitted above the tank will make 12-hour recordings of all behaviors of a single whelk during the trials. It’s looking specifically for the whelk to spend more time on one side or the other, its distance traveled and its rate of speed, even its propensity for turning.

"This is a good way for us test if there’s a preference for any of these types of baits," he said. Whelk, though slow, nevertheless "move around a lot in this tank," he added. About 20 whelk, acclimated in the tanks for 12 hours, will be monitored in the trials.

Whelk, which are deprived of food for three days prior to the experiments, feed by affixing themselves to the top of a clam or scallop, prying it open, injecting an enzyme inside and digesting the meat. Sclafani said a hungry whelk can eat up to two clams or scallops a day. Oddly enough, horseshoe crabs aren’t part of the normal diet for whelk, he said, but they are scavenger feeders and may encounter them outside the traps when a horseshoe crab dies on the bay bottoms.

"It’s not part of their normal forage base, so it’s an unusual arrangement," Sclafani said of horseshoe crabs and whelk. "There’s probably some chemical signature in there that is highly attractive to the whelk. Researchers are trying to get close to that scent with other baits."

By the fall, Sclafani said, Cornell hopes to have enough data to begin field tests of the alternative baits next year. Most fishermen already use fish racks — the bodies of fish shorn of their meat — to supplement horseshoe crabs in their traps.

The research is being funded by New York State's Department of Environmental Conservation and the Seatuck Environmental Association, a conservation group, each contributing $75,000. St. Joseph's University in North Patchogue,also a project partner, is contributing analytical software for the trials.

Helping to conserve horseshoe crabs "is something that means a lot to our members," said John Turner, senior conservation policy advocate for Seatuck Environmental. Horseshoe crabs are "an iconic species that a lot of people care about." 

Cornell is testing bait from shellfish and other parts bought or donated from local baymen, who will also be part of tests of new baits once the trials show promise of alternatives.

"Maybe someday someone will be able to synthesize what it is about horseshoe crabs that attract whelk," Sclafani said.

"If we find something that would be attractive to whelk, we’d bring it to the field, test that and see if it’s economically viable," he added, saying the work could have implications for the whelk fishery throughout the East Coast. "If it makes sense from fisheries' business perspective, [if] it is an affordable, reliable source, hopefully [we can] transition that into a horseshoe crab-less fishery."