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Horseshoe crab blood (and, why conservation pays)

Sabri Ben-Achour Jun 16, 2014

Horseshoe crab blood (and, why conservation pays)

Sabri Ben-Achour Jun 16, 2014

Quite possibly, the gentle horseshoe crab has swum ashore during the full and new moons of May and June to spawn for 445 million years. 

Horseshoe crab-like creatures were here when the dinosaurs appeared, and they were here after the dinosaurs disappeared. They survived ancient global warming and ice ages alike. And then people happened. 

“Over a hundred years ago, they were ground up and put on land as a fertilizer,” says Eric Hallerman, professor of fish conservation at Virginia Tech. In places like the Delaware Bay, 90 percent of the crab population was wiped out, and not a great many people cried about it. 

Then in the ’70s, people discovered that they need the crabs for something much more valuable.  

“Every human on the face of the earth, if they’ve ever been given an injectable medicine, has been touched by LAL,” says Allen Bergenson with biomedical firm Lonza. 

LAL – Limulus Amebocyte Lysate  is a test for bacterial contamination made from the crab’s blood (usually made without killing the crabs). Lonza is one of four companies that manufacture it. The test is used throughout the medical industry to ensure medical instruments and materials don’t cause fever or complications when introduced to the blood.

It’s among the reasons that, gradually, people and governments started to care about the crab. 

“We’ve created laws that make sure the animals are returned to sea, that require them to be harvested by hand,” says John Dubczak, general manager with biomed company Charles River Endosafe in South Carolina. In that state the industry lobbied to ban fishermen from harvesting hundreds of thousands of crabs to use as bait for sea snails and eels. 

The Atlantic States Marine Fisheries Commission intervened in 1998 to relieve pressure on the crab from the bait industry. 

Now, the biomedical industry is competing within itself to see who can use the fewest crabs. 

Charles River has developed a highly sensitive test that only uses one twentieth the normal amount of horseshoe crab’s blood. Lonza has a synthetic version that doesn’t use any crab’s blood. The firms argue, sometimes bitterly, over which product is better. The synthetic version doesn’t have the same regulatory standing as the crab-based version (it’s not currently listed in the United States Pharmacopoeia, an official list of sanctioned drugs and uses), and for now that has dissuaded the pharmaceutical industry from embracing it.

Whatever the result, the competition raises a different way of thinking about nature.

“Instead of nature for nature’s sake, nature for people’s sake,” explains Janet Ranganathan, Vice President for Science and Research at the World Resources Institute. She’s referring to a concept called “Ecosystem Services.” When people realize the value in nature, and then pay to maintain it, everyone wins. 

In many cases, this approach has saved entire ecosystems.

“In the ’80s, water quality was degrading in NYC because of development in the Catskill and Delaware watershed,” she says. Instead of building a $6 billion water filtration plant the city spent a fraction of that ($1.5 billion) just protecting the forests that purified water by paying landowners to maintain and restore it. 

It doesn’t always work, of course. Upstream agriculture on the Mississippi causes dead zones downstream that negatively affect fishermen, Ranganathan gives as an example. “You have one industry trumping another,” and polluters don’t have to pay for the disruption in services that nature provides. 

But things appear to be working out somewhat for the horseshoe crabs. Overall, the pressure on their population appears sustainable, according to the ASMFC, though there are troubling declines numbers in certain regions.

In some cases, making money off of nature can be a good way to protect it. 

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