Horseshoe crabs: How pharmaceutical companies have almost driven them to extinction

The blood of these crabs are overharvested for vaccine and drug testing, imperilling their populations.

High demand for blood of horseshoe crabs puts them at risk of extinction
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High demand for blood of horseshoe crabs puts them at risk of extinction

Horseshoe crabs’ population is fast depleting due to the high demand for their blood in the pharmaceutical industry. Conservationists fear the species of crabs could soon go extinct if this trend continues.

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Dangers of overharvesting

Known as a marine ‘living fossil,’ the 450-million-year-old crab provides a natural source of a substance called limulus amebocyte lysate (LAL).

It is used by pharmaceutical and medical companies to ensure that vaccines and a wide variety of medical devices and products are free from endotoxin contamination.

Endotoxins can cause fever, anaphylactic shock, and diseases like the bubonic plague.

It is estimated that several hundreds of thousands of horseshoe crabs are captured each year for their milky blood.

Ryan Phelan, executive director and co-founder of the environmental nonprofit Revive & Restore, said:

We’re going to live in a world where we have more and more pathogens and the trend is for more pharmaceuticals requiring endotoxin testing. At some point, that’s going to put pressure on the supply of a non-sustainable product.

Unprotected species

Horseshoe crabs are also overharvested for use as food and bait, a phenomenon that’s leading to habitat loss.

There are four extant horseshoe crab species and there are concerns more could follow, further impacting coastal biodiversity. They lay millions of eggs on beaches to feed shorebirds, fish and other wildlife.

The horseshoe crab has large hard shells that serve as microhabitat for species like mussels, snails and sponges.

In spite of this, Larry Niles, a wildlife biologist, says horseshoe crabs are not a protected species, and therefore not seen as valuable.

Yet they acknowledge that there’s a $500 billion industry for their blood, so they’re not worthless. They’re actually one of the most valuable marine species on the East Coast.
50 million crabs block roads as they migrate to the ocean to breed 50 million crabs block roads as they migrate to the ocean to breed