By Michele S. Byers
Humans weren’t the only ones shaken up when Super Storm Sandy tore through New Jersey last fall.
Wind, waves and storm surge resculpted much of the state’s coastline, with potentially disastrous consequences for two of our state’s iconic critters: horseshoe crabs and the Red Knot sandpipers whose lives depend on them.
The Red Knot is the ultra-marathoner of shore birds, migrating each spring from one end of the earth to the other, from its winter home in Tierra del Fuego at the southern tip of South America to its summer breeding grounds in the North American Arctic. The most crucial stop in this incredible journey is a layover in New Jersey’s Delaware Bayshore to gorge on eggs laid by horseshoe crabs.
Sandy damaged many of the best crab nesting beaches along the Bayshore, pushing sand into high dunes on the salt marshes and exposing mudflats, vegetative mats of marsh plant roots and age-old debris from abandoned fishing shacks. According to New Jersey Conservation biologist Dr. Emile DeVito, horseshoe crab nesting sites will likely be in short supply this spring.
Talk about bad timing! The state Senate and Assembly just introduced bills to lift the moratorium on the harvest of horseshoe crabs for bait. Bleeding of horseshoe crabs for lysate, an important pharmaceutical need, is allowed, but many of those crabs also die upon return to the bay. According to DeVito, understanding the scientific evidence gathered on the near-extinct Red Knot might help our legislators and citizens realize exactly what’s at stake:
For 25 years, New Jersey’s Endangered and Non-Game Species Program has coordinated a crackerjack team of shorebird scientists. They have painstakingly documented exactly what migratory sandpipers, especially Red Knots, need from New Jersey so they can arrive on their Arctic breeding grounds in healthy condition. And it all boils down to New Jersey’s Delaware Bayshore!
When Red Knots arrive at the Delaware Bay in late May, they must feast on excess horseshoe crab eggs. The only way to have excess eggs is by having super-abundant horseshoe crabs. When crabs are abundant, successive waves of females come ashore to nest, accidentally digging up other females’ nests from previous high tides.
Red Knots eat excess crab eggs that are dying, floating at the edges of the waves and on top of the sand – not the viable eggs that are safely buried 5 inches deep.
As recently as the 1980s, female horseshoe crabs would pile up on one another, jockeying for nesting spaces and digging up hundreds of millions of eggs! Then along came the bait industry, and the Delaware Bay horseshoe crab population plummeted. A harvest moratorium was instituted by the state in 2006 to recover this ecological phenomenon before Red Knots become extinct.
When enough crab eggs are available, Red Knots nearly double their body weight in a couple of weeks, so that when they arrive in the still-frozen Arctic, they produce and incubate eggs using the fat supply garnered in Delaware Bay. When the Arctic spring gushes forth a few weeks later, Red Knot eggs hatch with perfect timing for the healthy chicks to feast on plentiful insects. But without enough crab eggs in Delaware Bay, the Red Knot nests fail in the Arctic!
The data are irrefutable. Red Knot populations are teetering on the brink of extinction. There are so few birds that males and females may even have trouble finding one another when they arrive in the vast Arctic! Few juveniles have been seen on their wintering grounds in Argentina, indicating that the adult population of Red Knots is aging and not being replaced.
Horseshoe crabs nesting sites on Delaware Bay beaches remain spotty and insufficient, providing few dependable feeding areas for Red Knots. Egg counts are down, since too few female crabs are laying eggs.
So it’s no exaggeration to say this is the worst time to lift the moratorium on harvesting horseshoe crabs. With Super Storm Sandy changing the crab nesting landscape, our horseshoe crab population needs a chance to recover … in turn giving the Red Knot a fighting chance for survival.
“Now is not the time to repeal this important statute,” agrees Eric Stiles, president of the New Jersey Audubon Society.
“The horseshoe crab is an amazing species for many reasons, not the least of which is as a significant economic driver in our state,” adds Stiles. “The crab is a vital link in the chain which ends with a robust eco-tourism economy, upon which this state depends. The crab has been around for 450 million years and in a matter of a few short decades, we’ve decimated the population.”
The bills in the Legislature to lift the horseshoe crab harvest moratorium are not based on science. Let’s hope these bills are withdrawn, so Delaware Bay crabs will be spared from the bait market this spring!
For more information on Red Knots and horseshoe crabs, visit the Conserve Wildlife Foundation of NJ website at www.conservewildlifenj.org/species/fieldguide/view/Calidris%20canutus or the NJ Audubon website at www.njaudubon.org/SectionConservation/ShorebirdHorseshoeCrabConservationCampaign.aspx.
And for more information about preserving New Jersey’s land and natural resources, visit the New Jersey Conservation Foundation website at www.njconservation.org or contact me at firstname.lastname@example.org.