BROOKSVILLE (AP) – Scientists are hoping to learn more about Maine’s horseshoe crab population by tracking the mysterious creatures with transmitters and sponsoring a volunteer survey to count them.

Unregulated harvesting of horseshoe crabs for bait and medical uses has caused a severe reduction in the mid-Atlantic area – which in turn has increased harvesting pressure in Maine. The state two years ago put new limits on horseshoe crab harvests.

Still, little is known in Maine about the strange-looking crab, a prehistoric creature that has remained virtually unchanged for millions of years.

For the past three years, about 70 volunteers from local environmental groups have searched the coast as part of a weeklong, state-sponsored survey of the crabs. The count takes place after the full moon in May and the new moon in June, when the crabs migrate into Maine’s estuaries seeking spawning areas along the shores.

This year, scientists also plan to attach tags containing transmitters and batteries to 26 horseshoe crabs in Taunton Bay to track their whereabouts. The bay, located near Mount Desert Island in Hancock County, is thought to be the crab’s northernmost spawning ground.

Slade Moore, a scientist with the Department of Marine Resources, said the study, part of a larger assessment of the effects of fishing operations in the bay, will help scientists determine whether the crabs return to the same spawning grounds each year.

“We suspect that crabs in the New England area behave differently than in the mid-Atlantic, where they migrate over the continental shelf during the winter months,” he said. “In our area, they really don’t have much of a continental shelf, and some believe that they stay inshore throughout the year.”

Horseshoe crabs inhabit the East Coast from the Gulf of Mexico to Taunton Bay, said Pete Thayer, a DMR scientist who oversees the annual crab survey.

He said anecdotal stories from residents along some of Maine’s rivers suggest the crab populations at one time were so thick they had to be bulldozed off the beaches. Great Salt Bay on the Damariscotta River was one of the most heavily harvested areas along the coast, he said, and residents there reported as much as a truckload a day being taken from the bay.

For the annual surveys the past three years, volunteers have been scouring the shores looking for the crabs. Early counts this year were low, probably because the water is colder than normal, Thayer said.

The last formal assessment of the population was done in the late 1970s. Although that study did not tabulate specific numbers, it pinpointed population concentrations along the coast which have been targeted for the annual count.

The counts so far have been inconclusive, Thayer said. Because it takes a horseshoe crab about 10 years to reach sexual maturity, Thayer is uncertain how much of the population is being measured.

“We’ve gone about 20 years without seeing what they’ve been up to,” he said. “Now we’re trying to develop a solid baseline of information.”

AP-ES-05-26-03 1311EDT