Fred (chunking) I am glad there is someone else who remembers the crabs being a common sight all during the summer and very heavy in the early part.
I did some research as FishPicker hinted and I did learn some stuff...pretty disturbing stuff! Did you know that these critters are not sexually mature until age 10? And that they live for 15 to 18 years? At what age do stripers mature
How about the fact that the most desirable bait crabs are.......get this......Egg heavy females!!
Another case of the most vulnerable being sought for harvest. C'mon guys, You can't tell me this is not shortsighted?
The shortage of beaches thing is true but it is part of a double or triple whammy these crabs are getting. There does seem to be a shortage of crabs, if only anecdotally. If we don't see them, they are not there! The other problem with the current trawls is there is no real historic data to compare the trawls to. While it may seem like there are zillions of these crabs it should be noted that there are many accounts that the numbers up on the beach and breeding has declined. Another interesting fact about the crabs and why it is important that they be in great abundance is the role they play in the ecosystem. The crabs lay about 80,000 eggs each. While that may sound like a lot of eggs you have to remember the populations of birds they feed. It was designed that way millenia ago and we have disturbed it. If you reduce the #s of eggs, you reduce the numbers of eggs that survive and so reduce the population. Taking egg heavy females does much more damage. You are taking the eggs out of circulation, so they have ZERO change of survival. None have the chance to get past the birds and out to sea. Another interesting thing about these crabs, besides that they have been here since the Dinosaurs, they have few natural enemies. Sharks and sea turtles are the most notable. Sea birds will eat them if they are turned over.
I have attached a few things I found. Niles didn't write them either
In the News
Decrease in Crabs Raises Concerns
May 27, 2002
By JAMES GORMAN
For hundreds of millions of years, horseshoe crabs have spawned with relatively little fanfare. This spring, however, as they have hauled themselves up on the beaches of Delaware Bay, they have been counted, collected for bait, observed, and argued over.
Last fall, Jim Berkson of the Horseshoe Crab Research Center at Virginia Tech conducted one of the first extensive trawling surveys of horseshoe crab population.
This weekend, Berkson and his colleagues will be flying over the Delaware shoreline with digital video cameras to document the number of crabs on the beaches.
Environmentalists and birders are tracking the crab population as well, because a huge surge in the number of crabs collected for bait in the last decade, and a decrease in the number of the shorebirds that feed on them - red knots in particular - have caused alarm.
The issue is simple enough in its general outline, but one part is missing - how many horseshoe crabs there are, and exactly what is happening to the population.
There is no question that there has been an enormous assault on the population on the East Coast. In the 1990's, the take of horseshoe crabs jumped from the thousands into the millions, because of a burgeoning fishery for whelk (also called conch, or, on the plate in an Italian restaurant, scungili) and eels.
Perry Plumart, the National Audubon Society's director of government relations, wrote in 2000 on the proposed regulations to the Atlantic States Marine Fisheries Commission, "It is known that in the last five years alone between 15 and 20 million horseshoe crabs have been landed."
Observers had noted fewer crabs on the beaches in the spring over time, and several surveys showed a drastic decline in the availability of eggs, a main food for red knots and other shorebirds that stop to feed on their long migration. For some of the birds, being able to fatten up in the Delaware Bay is a matter of life and death. The bay is the most important stop for migratory shorebirds in the lower 48 states.
Lobbying by environmental groups managed to bring about restrictions on the harvest of crabs and the establishment of a sanctuary in the bay, but the harvesting is still going on and one significant problem is that horseshoe crabs take about 10 years to mature sexually.
Current restrictions, put in place by the fisheries commission and the individual states, still allow females heavy with eggs to be taken. The restrictions may be insufficient to protect the crabs and birds, according to Plumart and others.
Berkson's goal is to provide the solid numbers that will help the conflict to be resolved. He conducted a trawl survey off the Atlantic coast from Cape May, N.J., to Ocean City, Md., and said the estimate of the number of crabs in that area was a little over 11 million.
That did not include small crabs, he said, and, given the nature of the survey, the true number could be from 6 million to 17 million.
Given the harvesting rate in the past, that is not necessarily encouraging, but Berkson said there were horseshoe crab populations up and down the coast and at the moment, he said, the population was not endangered or threatened. What is not known, however, is how fast the population is declining and how fast reproduction is replacing crabs.
For Plumart, the lack of knowledge is a call to action, not only to research the numbers, which National Audubon strongly supports, but also to impose tougher restrictions. The numbers of crabs are declining, as are the birds, he says. And if we're not sure what's going on, that argues to play it safe, particularly since the birds need an abundance of eggs to survive their journey.
Dery Bennett, president of the American Littoral Society, agrees. "It seems to us as if the handwriting is there. We probably ought to lay off these animals completely."
Berskon said, "My opinion is that we have enough crabs out there for the shorebirds, for the biomedical community and for some harvest." What is not known, he said, is what level of harvest is tolerable to the crab population. "Nobody knows if measures taken so far are sufficient or overkill."
The issue is not merely one of conservation; horseshoe crab blood is a basis for a required biomedical test of bacterial contamination to determine the safety of drugs, intravenous solutions and some medical devices. Estimates of the size of the industry vary but it is at least $50 million. Berkson is currently waiting for an assurance that he will get money for the next trawl survey, as well as a federal appropriations measure that would provide $700,000 a year for five years for monitoring the horseshoe crab population.
In the meantime, the fishing continues, and another organization, the nonprofit Ecological Research and Development Group in Lewes, Del., is looking for technical solutions.
"We're an odd group within the environmental community," said Glenn Gauvry, the group's president. "We really are against regulation."
Instead, Gauvry's organization has been conducting research on alternative bait for whelk fishing, and on a very simple solution, that may be one of the only things everyone involved with the issue agrees on - bait bags.
The bait bag, first developed by a whelk fisherman, is simply an enclosure of rigid plastic mesh that protects the crab used as bait. Consequently, whelk fisherman can cut down on the amount of bait in traps because fewer creatures are able to eat it in bags, so it lasts longer.
The ecological research group now makes and gives the bags away free, and fishermen are starting to make their own. The bait bag, Gauvry says, could cut use of horseshoe
crabs in half.
Shorebird Crisis: The Horseshoe Crabs of Delaware Bay
by Don Crockett
So what has happened to get Pete Dunne, as he describes in the introductory piece, so frustrated and upset.
Back in the early 80's, Pete was among the first to document and describe the spectacular concentrations of shorebirds that were gathering along the shores of the Delaware Bay from mid-May to early-June (Wander & Dunne, 1981). Each year half a million to a million or more shorebirds arrive on the bayshores to feast on the eggs of the largest concentration of spawning horseshoe crabs along the Atlantic coast. Many of the shorebirds use this abundant supply of food to fuel the last thousand miles of their northward migration to the artic tundra. Red Knots, for example, arrive below their fat-free weight after flying 7,000 miles from southern Brazil. The knots need to double their weight during their 2-3 week stay in order to complete their journeys to artic Canada and breed successfully (Harrington, 1996).
Several years ago Pete and others noticed that the numbers of shorebirds and crabs seemed to be in decline. This seemed all too closely related to the increase in harvesting of the crabs as bait for the eel, whelk, and conch fisheries. Surveys that had first been performed in 1990 & 1991 to determine the density of available eggs for birds on New Jersey beaches, showed a 90% decrease when performed in 1995 & 1996. Censuses of spawning crabs showed a 2/3 decrease from 1990 to the present with most of the decline attributed to fewer crabs on the New Jersey beaches. Trawl samples performed in the bay showed a decline that correlated closely with the census data. Despite regulations put into place to restrict how and when horseshoe crabs could be harvested, the numbers of crabs taken each year in New Jersey kept increasing.
And then this year the numbers of spawning crabs and shorebirds plummeted in New Jersey. What had once been an awe inspiring spectacle that lined the shores with layers of shorebirds and horseshoe crabs was reduced to small isolated groups. Surface egg density surveys confirmed that there were very few eggs available for shorebirds. Aerial surveys of the bay found that birds that in previous years had been evenly distributed around the bay were heavily concentrated around one section of the Delaware side of the bay, the only place where crabs had spawned in large numbers.
The dramatic effects witnessed this year are not necessarily solely based on harvesting pressure. Environmental factors such as water temperature and the lunar cycle could also have influenced when and where crabs spawned this year. Shifts in the percentages of crabs on the Delaware and New Jersey shores have been documented in the past. No one knows for sure at this point what is causing the changes. Surveys do show that there has been a significant decline in the horseshoe crab population in the bay, and the commercial harvest is the most significant and controllable source of mortality in the horseshoe crabs.
Based on the dramatic changes observed this spring, a 60-day moratorium banning the harvest of horseshoe crabs in New Jersey was put into effect on May 31st by Governor Christine Todd Whitman. Several birding and conservation organizations are urging that a total emergency ban on horseshoe crabs be put in place in NJ, DE, MD, and VA until comprehensive regulations can be developed and put into place to ensure the sustainability of the crabs and the shorebirds that depend on them. On July 29th, Governor Whitman announced new strict regulations and extended the ban until the regulations could be put in place.
Regulatory processes will be influenced by public opinion and you can help by contacting people involved in making the decisions and letting them know that you support regulations that will protect horseshoe crab populations and the shorebirds that depend on them.
While every attempt was made to accurately portray the current situation and research findings, inaccuracies may have been included in this article. References to formal publications are provided for people interested in pursuing this issue further
Hard Times for Horseshoe Crabs
After millions of years, these Rodney Dangerfields of the aquatic kingdom are finally getting some overdue respect
From Outdoor Delaware Magazine
Story by: Kathleen Jamison
Photos by: Stephen Kirkpatrick
For millions of years, the high tides of late spring have drawn horseshoe crabs by the thousands from the bottom of the Delaware Bay and onto its Delaware and New Jersey beaches to mate and lay eggs. Millions upon millions of tiny gray-green eggs that somewhere on the biological time line have become a major source of food for hordes of half starved shorebirds on their annual migration from wintering grounds in South America to breeding grounds in the arctic.
No one knows for sure how many of these eggs successfully hatch, but estimates are that only one out of 130,000 eggs produces an offspring that reaches adulthood. Given that it takes about 10 years for a female to reach sexual maturity and that the average life span is only 18 years, the survival of the species depends in great part on mature females laying large numbers of eggs -- roughly 80,000 per female in a season.
Even with ruddy turnstones, red knots, semi palmated sandpipers, sanderlings, and a dozen other species gobbling up tons of eggs each spring, the ecological balance has remained fairly stable until very recently. Now some fisheries experts and conservationists are concerned that the resilient species -- which is not a true crab at all, but a close relative of spiders, mites and scorpions -- may be in trouble.
"There is no doubt that the numbers are down and that something is going on," says Charles A. Lesser, state fisheries administrator. "We just don't know what." We only started collecting information to assess stocks and to understand population dynamics in 1990 so we don't have the data base to compare what's happening now to what went on in the past."
In 1990 it was estimated that there was a spawning population of 1,200,000 crabs in the Delaware Estuary. In 1995, according to an annual census in which volunteers count the number of spawners coming ashore during a peak, one day period, there were fewer than 200,000. Lesser's best guess is that serious over harvesting is beginning to take its toll. Horseshoe crabs, especially the egg-laden females, are a favorite bait for eel, conch and catfish. With blue crabs scarce and other fisheries in a slump, some commercial fishermen are turning to horseshoe crabs to make ends meet. "At one point eelers were paying 85 cents to $1 per crab," says Lesser. "That brought out the gold rush mentality."
Shorebirds Looking For Eggs
Birders observing the migrating shorebirds were the first to notice the pickup trucks that were backing up to local beaches and hauling away loads of live horseshoe crabs. "That was back in 1988," according to Grace Pierce-Beck, who heads Delaware Audubon's conservation committee. "A few people have gotten cash for horseshoe crabs for years, but the money must have gotten better about then because all of a sudden there was a lot more collecting going on. When one of our birders asked a man with a truck load of crabs what was going on, he was told it was 'none of his business'."
Audubon members quickly made it their business, asking the Division of Fish and Wildlife to investigate. "We were concerned that over harvesting the horseshoe crabs could jeopardize the hundreds of thousands of shorebirds that depend on the horseshoe eggs to give them energy for the second half of their 6,000 mile flight," Pierce-Beck says.
Fisheries officials agreed that controls were needed. They worked with then Sen. Ruth Ann Minner to draft legislation giving the Department of Natural Resources and Environmental Control authority to establish a program for the conservation and management of horseshoe crabs.
Minner, who has since become Delaware's lieutenant governor, recalls the reaction the proposed bill elicited from her colleagues in the General Assembly. "They laughed," she says. "Most of them thought horseshoe crabs were a nuisance and that there were already too many messing up our bay beaches. It took some talking to convince them that we needed a way to make sure that the horseshoe crabs - and the birds that depend on the horseshoe crab eggs - weren't depleted by over harvesting."
A bill authorizing the country's first modern horseshoe crab conservation plan finally was signed into law by Governor Tom Carper on May 16, 1991. Regulations designed to slow down the harvest were written by Division of Fish and Wildlife biologists.
Delawareans wishing to collect crabs for commercial purposes must buy a $100 permit; the cost to nonresidents is $1,000. Permits to collect for documented scientific, medical or education purposes are free, but collectors are encouraged to take only males if possible and to return the crabs to their original habitat when feasible. Commercial eelers are exempt as long as they use the horseshoe crabs they catch for their own pots. A license for dredging, which accounts for about 60% of the Delaware catch, is $100 for residents and $1,000 for nonresidents; only five are issued each year.
"The horseshoe crabs that are picked up on the beach are the most noticeable, but only 22% are hand collected coast wide," says Lesser. "The big landings are from the offshore trawl fisheries. The commercial fishermen know where the horseshoe crabs are in winter, where they are concentrated, and that's when most of the trawling is done. They discount studies that indicate the numbers are dwindling dramatically."
The Delaware Bay is the center of horseshoe crab spawning. "To have any impact on protecting the resource, we need a regional management plan," says Lesser. Historically, Delaware has accounted for about 12% of the annual coast wide landings; New Jersey, 25%; Maryland, 45%; Virginia, 7%; and the New England states, 10%.
The Atlantic States Marine Fisheries Commission, which has the best shot at getting cooperation from all the states, has agreed to include a section on the use of horseshoe crabs as bait in the coast wide eel management plan it is not easy to do," says Lesser. "There are a lot of implications. After the draft is completed in late 1997 or 1998, there will be a round of public meetings, rewrites, etcetera . Actual implementation is several years away."
Horseshoe Crab Eggs
Last fall Delaware Audubon drafted a resolution asking state and federal officials to declare a moratorium on catching horseshoe crabs until the plan was developed. "Governor Carper wrote to the other governors in the region asking for their support and they all agreed, but that's as far as it went," says Pierce-Beck. "Until the federal management plan is in place, there will be no way to enforce any actions."
State fisheries biologist Stewart Michels is helping develop the plan. "Getting good data is critical," he says. "We can't arbitrarily close down the horseshoe crab fishery without justification and right now some questions remain unanswered. We hope to get more data and expertise from the other states to determine the status of the horseshoe crab throughout its range and, if necessary, enact reciprocal legislation to protect them."
With more data, Michels adds, "we hope to identify the impact of a number of factors are having on the population, including natural shifts in abundance and distribution, habitat loss and over fishing."
In 1990, the Division of Fish and Wildlife began collecting information on adult horseshoe crabs as part of its fin fish trawl survey. Sampling is done monthly from March through December at nine fixed stations in the Delaware Bay. The crabs are counted, measured and sexed. "At first we saw an equal number of males and females," Michels says. "Then in 1993-94 there was a decrease in the number of females that sent up a red flag about the potential for a population crash. Fortunately, the ratio corrected itself in 1995. We hope that is good news, but it could be that in the absence of the necessary number of females, the males are being hit harder."
In 1992, the Division began collecting statistics on juvenile horseshoe crabs in the Delaware estuary. Sampling is done from April through October at 34 stations. After a first-year low, catch rates have been fairly consistent. One interesting discovery that juveniles are most abundant near the mouth of the St. Jones River, with high concentrations occurring from the Little River to the Mispillion.
"Getting all the answers may take years," Michels admits.
In the meantime, some scientists, fisheries experts and conservationists believe that one answer could be artificial bait. "Something that is more efficient than catching horseshoe crabs and sawing them into pieces," says Lesser. Dr. Nancy Targett at the University of Delaware's Graduate College of Marine Studies agrees. She is seeking funds to study horseshoe crab eggs to find out what makes them attractive to eels and conchs, then duplicate those properties in artificial eggs.
"Management strategies have been proposed to reduce fishing pressure on these animals," Targett says. "Perhaps the best strategy to reduce fishing pressure would be to develop an artificial bait that could be substituted for horseshoe crab eggs. That would also divert horseshoe crab availability to higher value, sustainable uses like the production of Limulus amoebocyte lysate which is used by pharmaceutical companies to detect bacterial contamination in drugs."
Bleeding horseshoe crabs for the blood clotting agent lysate in their white blood cells is a process that does not harm the animals. After a technician takes about 12 ounces of blood, which turns a rich copper blue when exposed to the air, the crab is returned to the water.
The horseshoe crab also is used for vision studies because its complex eye structure is similar to the human eye. Though its scientific name, Limulus polyphemus, comes from the mythological one eyed Cyclops, the animal actually has nine eyes and a number of additional photoreceptors along its tail. Neurophysiologists are especially interested in the two lateral eyes on either side of the shell. They think these studies might lead to some answers about how the human eye and brain work together.
It's about time this unassuming and mildly alarming creature - a living fossil that looks like a helmet with legs and spends most of its life on the bottom of the bay - gets credit for its role in the well being of the ecosystem, not to mention human health. They've survived in their present form for 100 million years, so chances are they will be around a lot longer than the collectors who are threatening their numbers or the biologist and conservationists who are determined to protect them.
Still, if you are walking along one of Delaware's bay beaches next spring and see stranded horseshoe crabs, pick them up - gently and definitely not by the tail! - and put them back in the surf. Just for good measure.