THE VIRGINIAN-PILOT
Copyright (c) 1995, Landmark Communications, Inc.
DATE: Wednesday, May 17, 1995 TAG: 9505160143
SECTION: VIRGINIA BEACH BEACON PAGE: 02 EDITION: FINAL
SOURCE: Mary Reid Barrow
LENGTH: Medium: 96 lines
Most of us know horseshoe crabs only from the brown, tank-like forms that wash up on the beach after a storm.
But that is a very superficial acquaintance with the horseshoe crab. Those lifeless shapes are usually not even dead horseshoes. They are nothing more than the shells shed by growing creatures as a normal part of getting larger.
What we don't generally see on our beaches here are live horseshoe crabs because they crawl out of the water primarily only to lay their eggs in the sand. Farther north, however, where there are greater concentrations of horseshoes in the water, the spawn of the horseshoe crabs in late spring is a major attraction for nature lovers on some Maryland, Delaware and New Jersey beaches.
Freshly laid crab eggs attract hungry shorebirds and the shorebirds attract the birdwatchers, said Harley Speir, fisheries biologist with the Maryland Department of Natural Resources.
``There can be literally thousands of these things on the beach,'' Speir said. ``And people walk among them and the creatures pay no mind. They just bulldoze their way up onto the beach.''
The big females with the smaller males on their backs lumber up out of the surf and lay their eggs in a shallow nest in the high tide zone. They arrive most often in May and June on a high spring tide during the time of a full moon.
The males release their sperm and waves cover the eggs with sperm and sand. The miniature young hatch a couple of weeks later usually with the help of the next high spring tide which sweeps them back to sea.
It then takes 10 years for young horseshoe crabs to grow to spawning size themselves. The long time it takes for a crab to reach adulthood is one problem for horseshoe crab conservation, according to an article in the May issue of Bay Journal, a publication of the Alliance for the Chesapeake Bay Inc.
``Volunteers sought for horseshoe crabs survey'' raised concern that horseshoe crab numbers are declining because undeveloped beaches where the crabs can spawn are declining. While in the past, the prehistoric looking creatures were not considered to have much value other than as fertilizer, scientists now realize we need keep these awkward Army tanks around.
Not only are their eggs a valuable food source for migrating birds, the crab has become commercially valuable as a bait for the eel, conch and catfish fisheries. Horseshoes have proven to be valuable to humans, too. Their blood is used by medical scientists to detect bacteria in drugs and the animals also are used in several areas of medical research.
Concerns over possible declining numbers has prompted the Maryland Department of Natural Resources to conduct a survey to see if they can identify spawning beaches for the crabs that are not publicly known. Biologists like Speir and his colleague Tom O'Connell are wondering if there are beaches on islands or in other remote areas of the Bay where the crabs are breeding and no one has simply heard about them.
I have never heard of horseshoes spawning in this area, except in the Touch Tank at the Virginia Marine Science Museum. There with no tides or moon to guide them, females lay their eggs in the touch tank's gravel bed. The eggs often hatch into tiny crabs which, as in nature, are quickly eaten by other fish in the tank.
Still, you might know of a spot where you've seen horseshoe crabs spawn or you may have heard stories of where they have spawned in the past. If so, contact Tom O'Connell, Maryland Department of Natural Resources, at (410) 974-2241. Let me know, too. It would be interesting to discover that this odd creature has found a safe beach in our area.
P.S. TAKE A NATURE AND ECOLOGY WALK with refuge volunteer Vickie Shufer at 10 a.m. Saturday at Back Bay National Wildlife Refuge. The program is free but there is a refuge entrance fee. Call 721-2412 for reservations.
A MARKER AT THE SITE of the first church in Virginia Beach will be unveiled at 11 a.m. Saturday in the Church Point neighborhood. The public is invited to attend and hear the history of the church that is now beneath the waters of the Lynnhaven River. Park in the 4000 block of Church Point Road and a trolley will take you to the site.
SEE EAGLES AND A VARIETY OF NESTING SONG BIRDS on a trip to Flowerdew Hundred on the James River with the Virginia Beach Audubon Society Saturday. Meet at 8 a.m. at Galilee Church, Pacific Avenue, to arrange carpools. The fee is $3. Call Betsy Nugent at 428-4434.
LOCAL FOODS is the focus of the annual meeting of the Princess Anne County-Virginia Beach Historical Society at a covered-dish lunch at 2 p.m. Sunday at Nimmo United Methodist Church. Bring a dish, hear about our local food history and look through cookbooks that have been produced by local non-profit groups. MEMO: What unusual nature have you seen this week? And what do you know about
Tidewater traditions and lore? Call me on INFOLINE, 640-5555. Enter
category 2290. Or, send a computer message to my Internet address:
mbarrow(AT)infi.net.
ILLUSTRATION: Photo by MARY REID BARROW
Live horseshoe crab sightings are rare in this area, but they do
spawn in the gravel bed of the touch tank at Virginia Marine Science
Museum.
by CNB