Late spring along Raritan Bay in New York Harbor. Time once again for Atlantic horseshoe crabs (Limulus polyphemus) to experience urges to find a mate and create new life. Like clockwork it happens every May and June on full and new moon evenings. It’s a reproduction ritual that has persisted every spring for millions of years.
Horseshoe crabs and their relatives have been around for at least 440 million years, outlasting the dinosaurs, ammonites and even the trilobites, their closest known relative. Forget the reality television show on CBS. Horseshoe crabs are true survivors. It's an organism that has outlived about 99 percent of every other species on Earth. Horseshoe crabs have endured through four mass extinctions, including one that wiped out approximately 96 percent of all life, plus the trilobites. It occurred around 250 million years ago and it nearly ended all life on Earth. It was so devastating that researchers call it the “Great Dying.”
Yet, while other animals died out, the horseshoe crab survived. And it survives today almost identical to its ancient ancestors, being morphologically unchanged for more than 200 million years. It’s no wonder why many wildlife biologists call horseshoe crabs “living fossils.”
For many people, however, horseshoe crabs are a mystery, as are many forms of sea life. Something heard, but largely unseen and not quite familiar or fully understood.
If you were to come across a horseshoe crab for the first time you might think it’s a threatening helmet-shaped creature, likely to cause harm or injury, especially with a long tail that looks like a spear. For all one knows this creature can sting or attack?
Unquestionably horseshoe crabs are strange looking sea creatures. Something perhaps out of a second-rate 1950’s black and white science fiction movie like the 1957 Attack of the Crab Monsters where crabs attack people on a tropical island after radiation fallout.
But come on, you know better. Horseshoe crabs are not dangerous. They are harmless and gentle sea creatures. No one has ever died by touching a horseshoe crab. No one!
I remember as a young environmental educator working at a park along the Jersey Shore, I would sometimes pick up a live horseshoe crab off the beach and put it on my face or on top of my head to show off to people that these ancient forms of life are gentle. Sure, people at first would often gasp, gawk, or show great unease at the sight of seeing a person putting a live horseshoe crab on their face, especially with its legs moving widely. Eventually, though, people in the audience would get the point.
Horseshoe crabs are not crab monsters. Their tail, which is called a telson, is just used to help navigate the animal in the water and to also turn itself back over when caught up by a wave. Horseshoe crabs have no teeth or even a jaw, so they can’t bite. The pincers on the end of its legs are not very strong, just muscular enough to pick up small pieces of food, including small clams, crustaceans, and worms, and move the food into its mouth.
Horseshoe crabs are not only harmless to people, they are actually helpful. If you ever had a flu shot or any injectable medication or vaccine, or hip or knee surgery or any medical device implanted into your body in the past few decades, you owe your life to a horseshoe crab.
Their bright blue copper based blood is amazing; no other creature has it quite like horseshoe crabs. Their blood clots almost immediately when exposed to dangerous bacteria or fungi.
In the 1960s, a scientist working at the Marine Biological Laboratory (MBL) in Woods Hole, Massachusetts discovered that horseshoe crab blood clotted when exposed to marine bacteria. With further study, scientists were able to determine that a compound called LAL (Limulus Amebocyte Lysate) is responsible for the clotting. LAL, as part of the horseshoe crab’s immune system, releases proteins that can surround and kill bacteria, fungi, and—perhaps most importantly—proteins called endotoxins that are part of the cell structure of certain bacteria.
Their copper-based blood is an important reason why horseshoe crabs have outlasted the dinosaurs and many other forms of life on Earth. It’s also the reason the biomedical industry depends on LAL to make sure medical products don’t contain endotoxins, which can cause a range of problems for people from fever to burst blood vessels in the brain to even death. The U.S. Food and Drug Administration (FDA) requires all intravenous drugs and vaccines, and any medical device, such as replacement hips, hearts, pacemakers or knees, coming in contact with the human body to be first tested through the crab's blood for bacterial toxins, such as toxic shock syndrome, meningitis, and typhoid.
Additionally, several electronic companies use horseshoe crab blood in the form of a powder to detect damaged computer chips. The chips are so small that the presence of a single bacterium across two little elements in a chip could be enough to damage the computer chip.
Even more, horseshoe crabs are playing an important role in the research on how the human eye and the brain work together to give people vision. The crab's two large complex compound lateral eyes have been studied more than any other animal.
From a nonhuman and ecological standpoint, horseshoe crabs are an important part of a coastal food web, especially during springtime. Horseshoe crab eggs are fatty and full or protein. They are a major food source for several migratory shorebirds, including the federally threatened red knot. Many shorebirds have evolved to time their migrations to the arctic tundra to raise a family to coincide with peak horseshoe crab spawning activity in May and early June. They use horseshoe crab spawning beaches as an important rest stop, to fuel up and continue their journey northward.
And yet with all these benefits for people and birds, we still do an awful job of protecting and preserving horseshoe crabs. Their existence has come into jeopardy, particularly around New York Harbor.
Yes, you understand correctly. New York Harbor does have horseshoe crabs. Sure, maybe not as many as Delaware Bay, but there is still a viable population as of today.
What’s the problem? There are few current protections in place and horseshoe crab populations are just a small fraction of what they should be. One misstep and horseshoe crabs could totally disappear from New York Harbor, including Raritan Bay, Sandy Hook Bay and nearby tidal waters.
About thirty years ago there used to more horseshoe crabs roaming around New York Harbor, lots more crabs. So many crabs that beaches during May and June on or near full and new moon evenings would be covered from one end to the other with horseshoe crabs.
Sadly those days are long gone. Only small selected areas around the harbor remain as spawning sites for horseshoe crabs. Once these crabs and spawning sites are gone, New York Harbor will lose its horseshoe crab population for a long time, perhaps forever.
What could be causing such a dire decline in horseshoe crabs around New York Harbor? Humans and money of course.
One of the biggest threats to horseshoe crabs is the harvest by commercial fishermen to be used as bait for the American eel and channel whelk (conch) fisheries. Fishermen will use the body parts of horseshoe crabs as bait to attract eels and whelks.
New Jersey has instituted a moratorium on harvesting Horseshoe Crabs in 2007, but there is no such law in New York State. People are still able to harvest crabs. This action puts the crab population under severe threat in Lower New York Bay, and on the New Jersey side in Raritan Bay and Sandy Hook Bay.
Eels and whelks are highly valued in Asia and Europe for human consumption. Harvesters in the United States have turned to the American eel and Channel whelk fisheries to make money and meet the diverse needs for seafood in oversea markets. It's a global economy and our Horseshoe crabs in New York Harbor and along the shores of Long Island are often seen as bait and profit.
Since the 1990s, the price for a single horseshoe crab has jumped from .25 cents to more than $5.00 per crab. This might not sound like much money, but someone with a large trawl or seine net can easily capture 1,000 crabs or more in one evening and make over $5,000. Not a bad for nighttime work.
Pregnant females are repeatedly harvested more than males, since female horseshoe crabs are about thirty percent bigger than males. Females have more meat. Adult pregnant females also carry eggs, which make better bait.
The harvesting of horseshoe crabs is ideally managed by each individual state with oversight and regulations imposed by the Atlantic States Marine Fisheries Commission. For over 75 years, the commission is made of representatives from U.S. states formed to coordinate and manage fishery resources along the Atlantic coast of the United States.
Since 2009, New York State’s commercial quota for horseshoe crabs, as allocated by the Atlantic States Marine Fisheries Commission in their Horseshoe Crab Fishery Management Plan, has been around 150,000 crabs, with a certain amount of these captured crabs coming from Raritan Bay and along the south shore of Long Island.
While horseshoe crabs appear to be decreasing in the New York region, the annual quota for New York State has been unchanged since the quota program began in 2009. In addition, New York is the only state along the Atlantic Coast of the United States that has not placed a total or even a partial moratorium on harvesting Horseshoe crabs during their important breeding period. It would make better sense for the harvest of crabs to be carried out once the breeding season has completed. But the need for lots of money is strong in people.
There are also an undetermined amount of crabs in New York being harvested illegally during the breading season. For example, in May 2013 two men from Brooklyn were arrested for stealing 200 horseshoe crabs from an island, locally known as the Ruffle Bar, in Jamaica Bay, Queens. The two men were each charged with taking wildlife without a permit and disturbing wildlife breeding practices in a national park.
A woman was also arrested on an island in Jamaica Bay for illegally harvesting seven Horseshoe crabs on April 30, 2017. The women told officers with the United States Park Police in Jamaica Bay that she was harvesting crabs for her business. The body parts of horseshoe crabs in some parts of the world are considered to be an aphrodisiac for men and can command a high price.
Even in New Jersey where horseshoe crabs are a protected species, poaching still takes place. On the morning of May 23, 2011, Ocean City NJ police arrested three men from Philadelphia for illegally harvesting 132 horseshoe crabs fro bait.
These are just a few well-known examples of horseshoe crabs being harvested illegally. How many more crabs are getting captured illegally that are unknown or under the radar?
The second threat to horseshoe crabs around New York Harbor is their harvest for biomedical use. Although, as stated above, horseshoe crab’s cooper-based blood has remarkable antibacterial properties and enormous medical value that makes certain no impurities exists in medicines, the medical benefit for humans is not always a benefit for the crabs.
Horseshoe crabs are supposed to be caught, bled (about 30% of the blood from each crab is taken), and then returned to waters where they were found, but not all make it back. According to author Alexis Madrigal in a February 26, 2014 article in The Atlantic entitled, The Blood Harvest, “between 10 and 30 percent of the bled animals, according to varying estimates, actually die.” In addition, “bleeding a female horseshoe crab may make it less likely to mate, even if it doesn't kill it.”
Environmental scientists, John Tanacredi and Sixto Portilla, also tell us from a technical research paper published in Changing Global Perspectives on Horseshoe Crab Biology, Conservation and Management, 2015, that many crabs taken from New York State waters to be bled by the medical industry are often not returned to New York, including New York Harbor. From research on Horseshoe crab populations from Brooklyn to Montauk from 2003 to 2014, they found that numerous crabs permitted by the State of New York to be harvested and taken to East Falmouth, Massachusetts to be bled for the medical industry are often released “to local waters in Cape Cod, not back in NYS waters as required” by their permit. In the end, “many of those animals are re-harvested for bait and sold back to NYS fishermen at an average cost of US $5/crab.”
An undetermined amount of live horseshoe crabs are being caught, bled, and not released back in home waters to New York Harbor. Clearly, the bleeding of horseshoe crabs is an ecologically unsustainable practice that leaves thousands of crabs dead every year and a certain amount of crabs left for dead far away from home. The need for a synthetic alternative that eliminates the requisite for animal products in endotoxin detection is surely indispensable.
The third threat to horseshoe crabs around New York Harbor, including on the New Jersey side along Raritan Bay and Sandy Hook Bay, is just as menacing. The loss of spawning habitat from overdevelopment.
Horseshoe crabs need flat, sandy beaches on which to lay their eggs. But increasing levels of coastal development, from townhouses to seawalls to bulk-heading have created a hardening of the shoreline and have put pressure on New York and New Jersey’s horseshoe crab populations. The crabs are finding shorelines that are less natural, and more degraded, developed, fragmented, and crowded than habitats in the past.
More beaches are being lost to erosion, and in many cases, to bulk-heading. People often bulkhead their property in an effort to stop erosion and save their private property, but bulk-heading eliminates breeding habitat for horseshoe crabs by severely narrowing beaches.
As a result, prime spawning sites are being lost and more crabs, especially males, are coming ashore without mates. Reproduction is well below the maximum rate around New York Harbor.
All together, these threats are a major reason why New York Harbor beaches lack a high population of migratory shorebirds each spring. This has an important impact on the ecology of the bay. Decreasing amounts of horseshoe crabs and decreasing densities of horseshoe crab eggs means fewer crab eggs reaching the surface as food for migratory shorebirds. These birds need lots of horseshoe crab eggs for them to endure a long and hazardous migration. Without many horseshoe crabs on many beaches, there just isn’t enough food or enticement for shorebird success.
Please show some love for horseshoe crabs around New York Harbor! Please send emails to both Governor Andrew Cuomo and the New York State Department of Environmental Conservation to tell them to provide greater protection for horseshoe crabs and their habitat. Success first hinges on making sure New York State restricts the harvest of Horseshoe crabs, especially female crabs.
We need to strongly urge people in Albany to put a moratorium on Horseshoe crab harvesting to protect these prehistoric animals before it’s too late.
Moreover, please share the blight of the Horseshoe crab with friends and family. We need to make sure lots of people are aware that protecting horseshoe crabs in New York is absolutely necessary to ensure their survival in estuarine places like Raritan Bay, Sandy Hook Bay, and Jamaica Bay.
Hopefully, with greater awareness and public support, coupled with increased conservation efforts, horseshoe crabs, the ancient mariners of New York Harbor will once again fill beaches for many spring seasons to come. It would be great if we could protect the crab so they might endure for another 440 million years!
To find more information about coastal wildlife, including whales, please visit the website for Save Coastal Wildlife, a wildlife conservation nonprofit organization dedicated to educating people about the preservation and protection of coastal wildlife along the Jersey Shore at www.savecoastalwildlife.org