Monday, June 5, 2017

Jersey Beaches, Crabs and Birds

With summer nearing, many of us in New Jersey are ready to drive down the shore. No matter how bad the Garden State Parkway traffic might be, you'll never have the journey that some take to get to a Jersey beach.

These beach visitors come early, mostly before the official Memorial Day weekend that unofficially open the season here. They are birds that have to supply their own nonstop 6,600 mile flight over the Amazon rainforest and ocean,

Red Knots
Red knots arrive in New Jersey very hungry and lightweight and bulk up to twice their weight by eating horseshoe crab eggs and adding about 3 percent of their body weight each day.

For thousands of years, this ritual journey has been reenacted and the Delaware Bay has been the critical food rest stop for migrating shore birds each spring.

The red knots and ruddy turnstones are here around mid-May after their sojourn from South America.

Ruddy Turnstone
In the late 1800s and early 1900s, their stopover was not very satisfying. In those days, as many as 2 million horseshoe crabs were harvested each year and ground up as fertilizer for farms in South Jersey. That usage fell off as better fertilizers were found and was off by the 1960s.

There were a few decades when the main threat was fishermen who used the crabs for bait. In the late 1990s, the demand for them as bait for eel and conch fishermen increased. Those fishermen had been using shellfish bellies discarded by South Jersey processing plants, but when the processing plants started closing and waste disposal laws were made tighter, the supply disappeared.

The horseshoe crabs were also in demand for the biomedical industry. The crabs’ blue blood is used to make a clotting agent that helps detect human pathogens in patients, drugs and intravenous devices. Thankfully, in this process the crabs are returned to the water after blood is extracted, but not all survive the process. More than a half a million crabs were used for biomedical purposes in 2015.

Of course, not only were the crabs affected, but also the numbers of birds who were returning to the beaches.

After a steep population decline, a harvest management plan was put into place for horseshoe crabs in Delaware Bay, Where once 2.5 million crabs were taken annually, now New Jersey, Delaware, Maryland and Virginia harvesters are restricted to 500,000 male crabs and no females.

New Jersey has gone beyond the restrictions and has had a complete ban on horseshoe crab harvesting since 2008.


Horseshoe crabs at Reeds Beach

Hopefully, the Delaware Bay will remain the largest concentration of the prehistoric horseshoe crabs in the world. Red knot numbers have stabilized. Conservationists still work towards those numbers rebounding up. The red knot is considered threatened, and it is listed as endangered by New Jersey.

And after their visit to our state, the birds still have another 3000 miles to go to their breeding grounds in the Arctic. Think about that the next time you're stuck in Parkway traffic on the way to the beach.

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