Living the Scientific Life (Scientist, Interrupted)

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Horseshoe Crab, Limutus polyphemus,
a living fossil.

Image: Pier Aquarium, Florida [larger].

In a controversial ruling, a Delaware Superior Court judge partially rolled back the two-year ban on the horseshoe crab harvest by limiting it to males only. The decision was a reaction against John Hughes, secretary of the Department of Natural Resources and Environmental Control, who was actually doing his job. However, according to the judge, Hughes had already decided to enact a complete moratorium on horseshoe crab harvests after only considering scientific data, but before hearing any input from fishermen. Hughes imposed the two-year moratorium after seeing a decline in populations of migratory shorebirds that feed on horseshoe crab eggs.

Populations of shorebirds that “refuel” each spring on the crab eggs in Delaware Bay were found to be declining. Hughes was especially concerned by the dramatic decline in the population of red knots. The red knot is a small, rust-colored shorebird that migrates more than 9,000 miles from the tip of South America to their Arctic breeding grounds. Delaware Bay is one of their most important refueling stops during their epic journey.

Hughes said he was disappointed but not surprised by the decision, which he described as “a debatable legal decision by the court and a lousy environmental decision for the state.” Hughes then imposed his “fall back position” — a maximum harvest of 100,000 male crabs — a limit that complies with the Atlantic States Marine Fisheries Commission ruling. Delaware and other Atlantic states are required to adopt regulations that comply with the commission rulings. But Hughes adopted a more strict restriction: a complete moratorium.

“We’re good to go,” gloated Charlie Auman, the commercial fisherman who challenged Delaware’s two-year moratorium on horseshoe crab harvests. Previously, fishermen decimated the horseshoe crab population by overharvesting them up until 1998, thus reducing their numbers by nearly 80 percent.

Horseshoe crabs are living fossils, predating even the dinosaurs, and they are more closely related to scorpions, ticks and land spiders than crabs. Only four out of five species of horseshoe crabs are still alive today. Their numbers are dropping because of pollution, habitat loss, and overharvesting. Commercial fishermen harvest the crabs and use them for bait in conch and eel fisheries — which in 2005 alone had a dockside value of more than $200,000 in Delaware alone.

Rick Robins, owner of Bernie’s Conchs LLC, a Virginia conch processing business, who with Auman challenged Delaware’s harvest ban, said the limited, male-only harvest is a winning policy both for the commercial fishermen and the migratory shorebirds that feed on the crab eggs each spring.

“There’s no egg impact,” Robins claimed.

Of course, Robins neglects to mention, or to even consider, that the population of horseshoe crabs has been reduced by 80 percent already, so that factor alone has serious long-term impacts on the fishing industry, on horseshoe crab egg quantities and, in turn, upon migrating shorebird populations.

However, Hughes was not put off by the court ruling.

“We’re going to be watching” to make sure only male crabs are taken and there is no harvest overrun, he warned fishermen.

The ruling allows commercial fishermen to begin spring harvests on Monday.


Delaware Online (quotes).

Delaware Audubon; Horseshoe crab workshop: Will the red knot soon be ‘endangered’?

Horseshoe crab facts and figures.


  1. #1 Deb
    June 9, 2007

    I have read that there have been recent developments in creating new sources for bait for the eel/conch fishing. Instead of the horseshoe crab being the best and cheapest bait, apparently there have been advances in alternative bait. It seems that this is the best direction to support since it validates the fishermen’s needs to continue in their livelihoods and respects the horseshoe crab importance in the migrating bird cycle. Can this be investigated and reported upon so we can understand if the information is true?

  2. #2 "GrrlScientist"
    June 10, 2007

    thanks for mentioning this. i’ll look around to see what i can find.

  3. #3 Deb
    June 10, 2007

    You’re welcome. I’ll try to go back to see if I saved the article on line and send you the link where this was mentioned. It seems like an answer of sorts if it does work well as a bait, why wouldn’t it be promoted more? Give me a day or two.

  4. #4 daedalus2u
    June 11, 2007

    This is the same crab that is used in the limulus assay for endotoxin.

    As a source of blood for the LAL test, a single horseshoe crab can be worth $2500 over its lifetime (blood is harvested without killing them).

    Or as a few cents worth of bait? It is my understanding that just about anything can be used as bait.

  5. #5 Science & the City
    June 12, 2007

    The Long Island Horseshoe Crab Network, headed by Dr. John T. Tanacredi, is organizing a community horseshoe crab census to help identify horseshoe crab population trends and to target sites for future research.

  6. #6 Deb
    June 14, 2007

    This is one reference to a fisherperson trying bait for eels and conch other than horseshoe crabs…not successful according to the article, but laudable. I will keep looking for the reference I recall that held more hope. Just can’t find it easily but I’ll keep looking.


  7. #7 Deb
    June 15, 2007

    Here is one link to research that is looking into alternate bait for eel and conch:


  8. #8 mike
    June 9, 2008

    A lie is a lie..It just gets bigger over time …. Larry Niles claimed that fisherman over-harvested HC…No proof at all, Just that more people got permits to harvest, they never had them before..On may 7, 2008 ASMFC stated that the HC population is Higher now then in the 1990…What a lie this article states….an 80% decline, more lies…….The red knots are on the Atlantic coast of the entire east coast of USA they Will not count birds there….There is to many and would show an increase in red knots…I took pictures of thousands of red knot there in April and May before they start the counts of birds. If they see to many birds they wait a week or wait for a storm and then count birds this way there is low numbers….I see the methods to the madness

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