The horseshoe crab "spa".

Adding to the threats facing horseshoe crabs, a controversial pharmaceutical company just started harvesting their blue blood on Cape Cod…

Charles River Laboratories is one of just four companies in the United States — and now the second on the Cape — licensed to harvest the blood of horseshoe crabs for a valuable component that’s used to identify harmful bacteria during the testing of new drugs…

The Wilmington-based company’s state permit requires its staff to maintain the crabs in cool temperatures and return them to their habitat within 36 hours, but the work remains highly controversial. Tens of thousands of horseshoe crabs die every year along the East Coast as a result of such biomedical harvesting, according to the Atlantic States Marine Fisheries Commission, while studies have found that the crabs, after being bled, move more slowly, become less active, and appear to spawn less frequently.

They downplay their impact on a species that has survived for nearly 500 million years, comparing their facility to a “spa” and describing the helmet-shaped aquatic arthropods as “donating” their valuable blood before most are returned safely to the wild.

“We’re stewards of horseshoe crabs,” said Birgit Girshick, the company’s chief operating officer, who refused to let the Globe observe the Harwich operation. “We’re really proud of what we do. It’s all about patient safety.”



The destruction of horseshoe crabs is a hot button issue for me. I’m sickened by the human depredation of this animal which has survived for nearly 500 million years but could be driven to extinction by the use of this irreplaceable species for fishing bait as well as their blood harvesting.

Destruction of the horseshoe crab would also impact the many bird species that feed on the eggs along the Altantic flyway.

Some effort is being made to conserve the horseshoe crab.