Are Horseshoe Crabs Valuable?

The blood of the lowly horseshoe crab contains a chemical that can detect the smallest traces of bacteria in a test called LAL, which is short for Limulus Amebocyte Lysate. The blood test for bacterial contamination is big in the biotech business – drug developers depend on it, as do suppliers of surgical implants such as pacemakers and prosthetic devices. In fact, LAL from horseshoe crab blood can command $60,000 USD a gallon.

Horseshoe crabs live on the sea floor near the shore. When they want to mate, they swim into shallow water, and that's where they're nabbed. Processors pierce the tissue around the crab's heart and drain up to 30 percent of its blood. The crabs are then returned to the ocean 24 to 72 hours later.

Giving blood for mankind:

• The industry reports that 10 to 30 percent of the crabs die during the bloodletting process.
• In regions where horseshoe crabs are harvested for biomedical purposes, fewer and fewer females return to spawn. Researchers say the bleeding process makes them lethargic, less likely to follow tides, and less likely to mate.
• As a species, horseshoe crabs are more than half a billion years old. The copper-based, oxygen-carrying hemocyanin molecules in their blood make it baby blue in color.

Frequently Asked Questions

Why are horseshoe crabs considered valuable?

Horseshoe crabs are invaluable due to their blue blood, which contains a substance called Limulus Amebocyte Lysate (LAL). This compound is crucial for detecting bacterial endotoxins in medical equipment and vaccines. According to biomedical research, LAL tests are a standard for ensuring the safety of millions of medical devices and injections annually.

How does the horseshoe crab's blood benefit medical science?

The blood of horseshoe crabs benefits medical science by providing a natural detection system for bacterial contamination. The LAL from their blood coagulates in the presence of certain bacteria, making it an essential tool for pharmaceutical companies to test the sterility of their products, as noted by the FDA's guidelines for drug safety.

Are horseshoe crabs endangered?

Horseshoe crabs are not currently listed as endangered globally, but their populations are under threat due to habitat loss, overharvesting for bait, and biomedical use. Conservation efforts are in place, as the International Union for Conservation of Nature (IUCN) lists the American horseshoe crab as vulnerable, highlighting the need for sustainable management of this species.

What is being done to protect horseshoe crabs?

Conservation initiatives for horseshoe crabs include regulated harvesting, habitat protection, and research into synthetic alternatives to LAL. Organizations like the Ecological Research & Development Group (ERDG) work to preserve their habitats, while scientists are developing a recombinant factor C (rFC) to reduce dependency on horseshoe crab blood, as reported by conservation groups.

Can horseshoe crabs survive after their blood is harvested?

Horseshoe crabs can survive after a portion of their blood is harvested, but the process is not without risk. Studies suggest that mortality rates can vary, with some estimates indicating up to 15% may die post-bleeding. Efforts to refine bleeding techniques aim to minimize harm, ensuring a higher survival rate for these ancient creatures.

What other roles do horseshoe crabs play in the ecosystem?

Horseshoe crabs play a critical role in coastal ecosystems as a keystone species. Their eggs are a vital food source for migrating shorebirds, particularly the red knot, which times its migration to coincide with the horseshoe crab spawning season. The loss of horseshoe crabs could have cascading effects on these bird populations and overall biodiversity.