Hi Tweets,
Thought some of you might find this interesting...

Trileigh Stroh
Green Lake/Seattle University

---------- Forwarded message ----------
Date: Thu, 30 May 1996 07:52:35 -0700 (PDT)
From: Brenda I. Allen <allenb at seattleu.edu>
To: ecology-list at seattleu.edu
Subject: Of Birds and Horshoe Crabs


THURSDAY, MAY 30, 1996
NEW YORK TIMES

Horsehoe Crabs Dwindle, But Threat Is To Arctic-Bound Birds

By ANDY NEWMAN

REED'S BEACH, N.J. - As the tide goes out, the beach disappears beneath
a blanket of birds, screaming and near starvation after flying nonstop for
4,000 miles from South America.
Around them are spawning horseshoe crabs: jumbo-sized, helmet-shelled
relics of the Paleozoic Era, clacking against each other in the surf,
forming amorous conga lines six or seven crustaceans long, turning the
water cloudy with millions of milky-green eggs, getting flipped over by
waves on the beach and writhing mutely as they die.
For 350 million years, the greenish-brown, spike-tailed horseshoe crabs
- not crabs at all, but 10-legged arthropods closely related to spiders -
have surged ashore every spring in a slow-motion mating frenzy.
For the last few thousand years, they have done it in greater
concentration along the mucky shores of the Delaware Bay than anywhere else
in this hemisphere, a fact that has not escaped the notice of the
participants in the largest shorebird migration east of Alaska.
The birds - more than a million sanderlings, red knots, ruddy turnstones
and a few other species - each gobble up to 9,000 little green eggs a day
for two weeks, doubling their weight before flying off to the Canadian
tundra to nest.
But the spectacle that usually accompanies the high tides of the full
and new moons in May has been muted along the bayshore for the last two
years: the crabs' numbers, state researchers say, have dropped sharply,
posing a threat not so much to the crabs, who are found all along the
Eastern seaboard, as to the shorebirds, who have no other plentiful food
source at this time of year to fuel their migration.
``I was looking at a photograph the other day from four or five years
ago,'' said Fred Mears, a naturalist for the New Jersey Audubon Society's
Cape May Bird Observatory who leads daily tours of Reed's Beach, 12 miles
up the coast from Cape May. ``There was no way you could walk down to the
water without stepping on crabs. Now there's maybe half as many.''
No one is certain about what happened to the crabs. This year, the cold
spring has set them behind schedule. But state wildlife officials suspect
the main culprit may be overfishing by crabbers who dredge the creatures
from the bay or simply pick them from the beach like fallen fruit, and sell
them as bait for eel and conch traps.
Estimating the total population of horseshoe crabs has proven difficult.
A half-dozen surveys of the bay's crab population over the last decade show
widely varying numbers, from hundreds of thousands to more than 4 million.
But all show a downward trend.
And in the three years that the state has been requiring crabbers to
report their catches, the harvest has jumped to 369,000 crabs from 252,000,
due in large part to increased demand for eels in Japan and Europe.
Last month, the state Bureau of Marine Fisheries, which issued 300
permits last year, cut back on horseshoe crabbing, moving the hand-crabbers
a thousand feet off the beaches into back bays and tidal streams, limiting
hand-crabbing to two days a week, and completely closing the offshore crab
beds during the month of May.
The crabbers say the counters are using the wrong equipment and are
simply looking for crabs in the wrong places.
``There is no shortage of horseshoe crabs in the Delaware Bay
whatsoever,'' said Charles F. Burke Jr., a fisherman from Cape May who
fought the new regulations.
Even a modest decline in the spawning population could spell trouble for
the birds, because it takes a high density of crabs to make the eggs
accessible. The she-crab deposits her eggs - up to 4,000 at a time - 7 or 8
inches down in the sand, out of reach of the relatively short-billed birds.
When another crab comes along to lay in the same spot, she disturbs the
first nest, pushing the eggs up toward the surface where the birds can get
at them.
``The shorebirds depend on there being not just a lot of horseshoe
crabs, but a really lot of horseshoe crabs,'' said Joan Walsh, a biologist
with the Cape May Bird Observatory.
Despite last year's poor showing by the crabs, the birds are back in
full force on Reed's Beach, said Kathy Clark, a principal zoologist for the
state Division of Fish, Game and Wildlife. But that does not mean they are
getting the nourishment they need.
If they are not, Ms. Clark said, the birds might stay longer on the bay
to feed, cutting into their short nesting season. Or they might depart on
partially empty stomachs and arrive in Canada too weakened to lay a full
clutch of eggs.
Two-thirds of this hemisphere's population of the red knot - an
orange-breasted, robin-sized bird - are believed to visit the Delaware Bay
each year, as are 35 percent of the sandpiper-like sanderlings.
``These birds are on a really strict timetable about getting to the
Arctic,'' Ms. Clark said, ``so for them to be compromised by low weight
really has an impact.''
A few miles up the coast from Reed's Beach and 2,000 feet inland, along
a road through the marsh that floods with every tide, Burke's claims of
abundance seemed justified.
At the stroke of midnight May 23 - the beginning of one of the week's
two permitted crabbing days - Mike Litchko and his four-man crew fanned out
along a stretch of what looked like horseshoe-crab soup. For at least five
feet out, the water, illuminated by powerful lights mounted on Litchko's
truck, was thick and churning with crabs.
The young men stooped in the shallows, turning the crabs over to
determine their sex. (Where the female has two extra claws, the male has a
pair of hooks shaped like crooked fingers that he uses to latch onto the
back of the female, or the male closest to the female. Crab eggs are
fertilized in the nest, and the first male in line has the best chance of
passing on his genes.) Females were tossed into plastic crates, males back
into the bay.
The job often involved breaking up couples. ``As soon as they get it,
they get it taken away,'' one of the workers, Tom Loscar, said as he
planted his hip wader on a male and yanked the female loose. ``I wouldn't
want to be them.''
The female crabs, which at up to 5 pounds and a foot in diameter run
double the size of the males, fetch 40 to 60 cents apiece from bait
distributors.
Litchko said the man who bought his crabs would take them to Virginia
and sell them to eelers for a dollar apiece. By dawn, the crew had filled
Litchko's box truck with 1,880 crabs.
Litchko, 38, of Dennisville, who has been a professional fisherman since
the age of 12, said that the crab population has flourished on inland
marshes in the two years since Public Service Electric & Gas Co. restored
14,000 acres of salt hay fields along the coast to their natural swampy
state.
``The crabs are congregating in phenomenal numbers on the estuaries,''
Litchko said. ``There's more in the estuaries and tributaries now than
there are on the beach.''
Burke and several other crabbers had harsh words for ``environmental
do-gooders'' who, they say, are making it difficult for them to earn a
living.
But Ms. Walsh of the Audubon Society contended that the question is not
simply one of crabbers' jobs versus protecting the environment. The
crab-dependent shorebird migration is the linchpin of the Cape May area's
$10-million-a-year birding industry.
Crabs are also important medically. A laboratory in Dias Creek, several
miles down the coast from Reed's Beach, draws blood from the crabs - a
process that does not harm them - to make a compound called lysate that is
used to detect toxic bacteria on pacemakers, prostheses and other foreign
objects that are placed in the human body.
Lawrence J. Niles, the head of the nongame and endangered species
program in the state Division of Fish, Game and Wildlife, said he doubted
the state was being pessimistic.
``It looks to me,'' Niles said, ``that not only did we take correct
action by restricting the harvest, but there is ample room to suggest that
maybe we should be going further.''
On the other hand, when the full moon reappears June 1, the crabs might
storm Reed's Beach again.
``I'd love to be wrong,'' Niles said. ``That would be really great.''
00:58 EDT MAY 30, 1996