Conserving Wildlife, Delaware Bay, Science

A recovery as slow as a horseshoe crab on a cold day


We begin our Delaware Bay Shorebird Project on both sides of the bay this week and as always, it’s a time to look at our program and see where we are and ask the question where would we like to go?  What is happening to the birds, the horseshoe crabs, are things getting better.

The most recent horseshoe crabs surveys suggest there has been no improvement in horseshoe crab numbers since the ASMFC began its regulations affecting the harvest of crabs in 1998.  Moreover the survival models developed for horseshoe crab and red knots developed by a team of scientists, including me, suggest a recovery period of decades.  In the meantime red knots, one of many shorebird species that rely on the horseshoe crab’s eggs, are fast heading towards extinction and the listing of the knot is imminent.  Other species. like the ruddy turnstone, will almost certainly follow as well as some of the 60% of shorebird species now in decline.  These birds cannot wait for an anemic approach to restoration.

Ironically if you ask the ASMFC management board if more can be done, they will say no. They argue that the harvest is effectively closed now.  That don’t include the half million crabs killed by fishermen in DE, MD and VA .  These animals , they will explain,  are either excess males, and thus unnecessary to population, or outside the Delaware Bay population.  They will also point out a recovery is underway, not recognizing the threat to all shorebirds of a recovery that many take several human generations to accomplish.  Getting serious action from this agency that has had a hand in the decimation of the bay’s Atlantic Sturgeon, River Herring, Weakfish would be a herculean task.

Can nothing more be done?

We could close all harvests, making it illegal to hold a horseshoe crab at all, and not reopen it until a recovery is underway.  This is what NJ did for crabs, and the ASMFC did for striped bass.   Why not do it for the crabs throughout the range?  The incentives would be properly aligned in this way,  use depends on restoration.  Now  there really is no financial incentive to restore crab populations..

Notwithstanding the logic, strong action of this kind is unlikely when the people making money from crabs benefit from inaction and the people who care for shorebirds have no substantive voice ( or choose to not speak loudly).

Given this, there are four actions that can make more crabs or more eggs available to birds now.

1. Stop all major sources of illegal use.   Are trawlers taking crabs in international waters and using them as bait without landing them thus avoiding accountability?   Are crabs being taking illegally and landed secretly?  Are fishermen underreporting or reporting their take as males, when they are really more valuable females.  We need a smart investigation into the killing of horseshoe crabs other than the reported harvests and act to stop it.

2. Expose to the light of day the secretive bleeding operations of companies extracting lysate from horseshoe crabs and insure mortality of no greater than 5%.  Currently the bleeding of crabs is cloaked in secrecy and peer reviewed estimates of mortality are far higher than industry reports.  There needs to be a baywide effort to make the bleeding of crabs an above board enterprise and force the drug companies, who earn in excess of of $200,000,000 from the blood of crabs,  to take part in restoration.


3. Improve marginal breeding habitats on the bay by creating wave attenuating oyster reefs and introducing new sand to depleted beaches.  Currently more than half of the suitable breeding habitat in the Delaware Bay is marginal for horseshoe crab breeding.  We need to quickly increase the area, but also make it easier for crabs to lay eggs unaffected by wind driven waves.  We call these wave-protected areas mini-Mispillion harbors,  a jetty-protected Delaware Beach where crabs lay eggs in enormous quantities.

4. Mobilize the public into a massive crab rescue project.  Ever year thousands of crabs overturn from heavy surf , many failing to right themselves and dying from desiccation or attack from gulls.   Other crabs die after being impinged in breakwaters, bulkheads and other water structures.   We need to gear up programs like Glen Gauvry’s Flip a Crab program to rescue all crabs that can be rescued.

5.  Expand Manomet Center for Conservation Sciences nascent social marketing program so that the public can take part in the actions like those listed above and begin the process of overcoming lethargic regulatory agencies.


These five efforts would give shorebirds and crabs a new start by changing prospects right away, instead of waiting for a recovery that could take generations to achieve.