Horseshoe crabs may be pushed to the brink of extinction because of the value of their blood to the pharmaceutical industry

According to The Verge, some conservationists worry that horseshoe crabs, a 450 million-year-old “living fossil,” will be pushed to the brink of extinction because of the value of its blood to the pharmaceutical industry. The blood of horseshoe crabs provides a natural limulus reagent for testing vaccines, drugs, and medical equipment to ensure that they are not contaminated by dangerous bacterial toxins called endotoxins. As hundreds of thousands of horseshoe crabs are captured and receive blue blood each year, conservation organizations are now stepping up their publicity efforts and taking legal actions to help save horseshoe crabs and other species that depend on them.

Fortunately, there are already substitutes for horseshoe crab blood: in the late 1990s, biologists at the University of Singapore created a synthetic version of the limulus reagent called Recombinant Factor C (rFC). Many studies have shown that rFC is as effective as horseshoe crab-derived limulus reagent, and it is currently available on the market.

Approximately 60 countries have approved the use of rFC, including EU countries and China. But in the United States, protectionists encountered setbacks last year. US Pharmacopeia (USP), headquartered in Maryland, an organization that sets guidelines for the pharmaceutical industry, decided that before putting rFC and limulus reagents on the same level, they need to see more Much data. Companies can still choose to use rFC as an alternative to limulus reagents (Eli Lilly has already done this) – but only if they pass additional bureaucratic procedures first. Many environmentalists believe that USP’s failure to approve is short-sighted and unwise.

“We will live in a world with more and more pathogens, and the trend is that more drugs require endotoxin testing,” said Ryan Phelan, executive director and co-founder of Revive & Restore, an environmental non-profit organization. “At some point, this will put pressure on the supply of unsustainable products. Why don’t you guarantee your supply line?”

The global pharmaceutical and medical industries use limulus reagents to ensure that vaccines and various medical equipment and products are not contaminated by endotoxins, which can cause fever, anaphylactic shock and diseases like plague. During the test, the limulus reagent condenses around the endotoxin, marking their presence and quantifying the degree of contamination. The high demand for this compound can cost a quart of limulus reagent for $15,000 or more.

Therefore, the horseshoe crab bloodletting business is booming. Today, biomedical companies in the United States catch about 500,000 horseshoe crabs each year, and this practice is overseen by the Atlantic Ocean Fisheries Commission. However, there are few laws or regulations to protect or restrict the fishing of horseshoe crabs. Although horseshoe crabs will eventually be returned to the sea, conservation organizations estimate that up to 30% of horseshoe crabs die in the process. Due to pressure from the biomedical industry, combined with habitat loss and commercial fishermen fishing horseshoe crabs as bait, the number of horseshoe crabs in the United States and around the world has fallen sharply in recent decades.

In the Delaware Bay, which has the largest number of horseshoe crabs in the United States, the number of horseshoe crabs has dropped from 1.24 million in 1990 to less than 334,000 in 2002. Although the number of horseshoe crabs appears to have stabilized, conservationists worry that the increased demand for blood from American horseshoe crabs by the pharmaceutical industry may force it to follow the path of Tachypleus tridentatus, which has quickly disappeared and was approved by the International Union for Conservation of Nature (IUCN). ) Is listed as an endangered species. Currently, horseshoe crabs are classified as vulnerable species in the United States.

Relying on horseshoe crab medicine has had a knock-on effect on other species. As part of the bloodletting process, Charles River Laboratories (one of the main manufacturers of limulus reagents) sealed horseshoe crabs in shelters away from the beach from May to June, the season when they spawn. During this time period, a female horseshoe crab can lay as many as 80,000 eggs. Environmentalists believe that removing horseshoe crabs from the beach will reduce horseshoe crab eggs as a food source for coastal birds, such as migratory red-bellied sandpipers. In recent decades, as a threatened species in the Endangered Species Act, the number of red-bellied sandpipers has fallen by 80%. Conservationists believe that this decline is related to the reduced supply of horseshoe crab eggs.

Because of this connection, environmental non-profit organizations Defenders of Wildlife and Coastal Conservation League recently notified the South Carolina Department of Natural Resources and Charles River Laboratories that they intend to sue these two entities for alleged violations of the Endangered Species Act. The lawsuit seeks to protect the food source and habitat of red-bellied sandpipers by requiring the state government to end the practice of captive horseshoe crabs in Charles River Laboratories.

Defenders of Wildlife’s lawyer Lindsay Dubin told The Verge: “The pond maintained by the agent at Charles River Labs further jeopardizes the survival of the red-bellied sandpiper. The fate of this species is up in the air.”

The South Carolina Department of Natural Resources declined to comment on the lawsuit. Charles River’s laboratory declined to provide specific answers regarding their practice of keeping horseshoe crabs in captivity or its impact on the red-bellied dunlin population. Sam Jorgensen, a spokesperson for Charles River Labs, wrote in an email statement to The Verge that the company does not believe the lawsuit is meaningful and it has taken steps to “protect and maintain the health and the growing number of horseshoe crabs.” , Including support for the ban on the use of horseshoe crabs as bait in eel and snail fisheries. Jorgensen also pointed out that horseshoe crabs play a “vital role” in the healthcare system, and synthetic substitutes for limulus reagents are “not easily available” and have not been approved by the FDA.

However, despite the current bureaucratic obstacles to the widespread adoption of rFC in the United States, advocates continue to urge to change their dependence on horseshoe crab blood. In addition to being more humane, rFC is produced in the laboratory, so the company does not have to worry about the size difference or the number of individual horseshoe crabs, these factors will affect the production of limulus reagent. If demand increases, manufacturers can produce more rFCs on a large scale, which may reduce production costs and make their prices lower. Critics of rFC like Charles River Labs (it is worth noting that if rFC is more widely used, the lab will lose business) insist that rFC needs further research and testing to prove that it is completely safe, and Fully determine its efficacy.

This debate is particularly critical at the moment; the COVID-19 pandemic has driven a wave of research on vaccines and potential COVID-19 treatments, and these studies rely on the use of limulus reagents to ensure product safety. As the demand for vaccines and other medical products increases, conservationists worry that if they do not quickly switch to rFC, the pressure on horseshoe crabs and other organisms that depend on them will only increase.

Larry Niles, a wildlife biologist and an expert on environmental issues in the Delaware Bay, said there is an inherent contradiction in the way that state and federal agencies view horseshoe crabs. He said horseshoe crabs are not a protected species, so they don’t think they are valuable.

“However, they admit that there is a $500 billion industry for their blood, so they are not worthless,” Niles said. “They are actually one of the most valuable marine species on the east coast.”

It remains to be seen whether lawsuits and increasing pressure from the public and environmental groups will force state and federal agencies to more strictly regulate and protect horseshoe crabs, or promote the adoption of rFC. However, Phelan hopes that eventually laboratories and other pharmaceutical industry participants will recognize the benefits of rFC, both in terms of cost and reliability. She said that the adoption of rFC will benefit both the company and horseshoe crabs.

Phelan said: “For any pharmaceutical company that adopts this technology, this is a win-win result, because they will have better quality control and better scientific output. Moreover, their employees and their interests are related Owners or shareholders will feel better because they are doing the right thing for the ecosystem.”