It’s early on a hot August morning at the Naples Zoo, yet 60 volunteers packed into a classroom are excited to be learning how to convince a horseshoe crab to submit to a brief but proper welfare check.
Officials with the Florida Horseshoe Crab Watch Program are hoping everyone there will graduate to become citizen scientists, willing to carry a notepad and pencil and walk along the region's beaches looking for members of a species far older than the dinosaurs.
The amount of real-time information volunteers can collect about the ancient creatures is far more than biologists, who are often busy in the lab, could find and compile: where the crabs are congregating, how many are around, and what they’re doing which is quite often mating— quite often making baby horseshoe crabs.
The morning's class is a first run at teaching beachgoing volunteers willing to stick their noses into the crabs’ business what to do, how to do it, and the proper way to record and input what they discover.
It’s important work.
Countless humans have been kept from dying thanks to a compound in the animal's blue blood that has the unique ability to ensure the safety of vaccines, injectable medications, and medical devices.
The Food and Drug Administration requires a whole slew of medical items to pass testing using horseshoe crab blood to detect dangerous bacterial contaminants in medical products.
Taking blood from horseshoe crabs has been done since the 1970s; initially in ways that killed the animal. Today, in theory, labs take some of their blood and return them to the ocean. Still, studies show at least 15 percent of the animals don’t recover from the process and die.
Naples resident Deborah Woods has been active for four years in citizen-scientist programs focusing on seagulls and eagles, but arrived early at the Naples Zoo for the horseshoe crab course.
She said part of her motivation was to help researchers better understand the way horseshoe crabs help humans live. But she was also there to bolster the significance of citizen science in preserving natural opportunities for future generations as the climate changes and beaches disappear under rising seas.
“I have a love for the citizen science and the connection with the horseshoe crabs,” Woods said. And “providing the data for sustainability going into the future so that my grandkids will have the same opportunities that I do for loving nature.”
A national movement
It's an overstatement to say a majority of humans are alive solely because of horseshoe crab blood. At the same time, it is an understatement to say that the animal’s blood has played less than a crucial role in modern medicine and saved less than hundreds of thousands of lives.
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The recent citizen scientist class at the Naples Zoo mirrors those offered throughout the country, where volunteers receive training to accurately identify horseshoe crabs and distinguish between young and old.
They help biologists studying horseshoe crabs learn how to conduct surveys on beaches during spawning season, using standardized techniques to count and record crab numbers, often with the help of dedicated apps or online platforms.
Citizen scientists can also monitor potential threats to horseshoe crab habitats like beach erosion, pollution, and human disturbances.
Now volunteers monitor more than 1,300 miles of Florida coastline.
Horseshoe crab citizen science programs have also taken root along the Atlantic coast, engaging volunteers in crucial data collection efforts.
From crowded beaches in New Jersey to remote shorelines in Florida, the horseshoe crab citizen science movement has become a springtime ritual for many coastal residents and beach lovers, providing a vital link between scientific research and public engagement.
Cornell Cooperative Extension's Marine Program coordinates a network of volunteers on Long Island. Their goal is to monitor spawning horseshoe crabs at various beaches to gain a better understanding of their abundance and distribution in the New York Marine District. Volunteers collect data on spawning abundance, size, sex, and tag returns around full and new moons.
In New Jersey, Save Coastal Wildlife has been monitoring horseshoe crab spawning activity along the northern Jersey Shore since 2009. Volunteers conduct surveys during full moon and new moon evenings in May and June, counting crabs and tagging individuals to track their movements within the New York Estuary
These programs not only contribute valuable data for research and conservation efforts but also foster public engagement and awareness. Volunteers often become passionate advocates for horseshoe crab conservation, spreading knowledge about these living fossils in their communities.
Scientists need the help
Samantha Easterling, the volunteer coordinator for the Collier and Lee County Horseshoe Crab Watch programs, said the program's primary mission is to engage community members in scientific research.
Easterling and other coordinators taught the packed room of 60 volunteer citizen-scientists at the Naples Zoo earlier this month how to properly measure, count, and tag horseshoe crabs.
She also said U.S. scientists need the help.
“Worldwide, the biggest risk is actually biomedical. So they use horseshoe crab blood to test products for anti-clotting materials,” Easterling said. “But in Florida, the actual biggest threat is the aquarium trade.
"We don't know a lot about our horseshoe crabs in the State of Florida, and so this project that we're doing with Florida Horseshoe Crab Watch is really to learn more about them so that we know how to better protect them in the future.”
She said the program aims to increase public awareness and involvement in monitoring horseshoe crabs, animals that are crucial for ecosystem health and as food sources for other species.
Horseshoe citizen scientist classes may be popular among environmentalists just caring for nature, but less well known is how much the creatures do for humans: a compound in the animal's blue blood with the unique ability to ensure the safety of vaccines, injectable medications, and medical devices has saved countless human lives.
The volunteers were also taught how to report sightings of horseshoe crabs, determine their gender, and flip them back over without hurting them (a few fingers on each side of their shell; never by the tail) all while collecting valuable data to share with professional biologists monitoring Florida’s population of the animal.
“Horseshoe crabs serve such an important role in our ecosystem, and so we just really want to get scientists, community scientists, out there to understand these animals and then advocate for them and want to protect them.”
The good news for coordinators like Easterling is that their time spent training citizen scientists results in a quality payoff.
A recent study published in the journal “Citizen Science: Theory and Practice” found that data collected by properly trained citizen scientists is as accurate as information collected by professionals.
Filling in gaps
Horseshoe crabs have been around for more than 450 million years, which means they watched the extinction of the dinosaurs, survived ice ages, and switched from saltwater-based creatures to freshwater-based, and back, several times.
Anyone who has watched any of the scary “Alien” movies could probably imagine the horseshoe crab as the inspiration for the baby aliens that come flying out of the space eggs and face-plant on a human to reproduce.
Despite having "crab" in its name, the animal is closely related to the extinct sea scorpion and the still very much alive land scorpion. But horshoe crabs do not sting.
Horseshoe crab populations have been declining due to harvesting them for their blood, but they are still all over the place in the shallows during their twice-a-year mating season.
The bleeding process not only kills a portion of the crabs returned to the sea, it leaves some unable to reproduce.
“Science costs a lot of money, and unfortunately, a lot of funding gets cut for a lot of science projects,” Easterling said. “And so if we can recruit citizens who care, and citizens who you know want to pay
attention and want to help, that is free help that we can get. And so this is so important. We look for mating pairs,” he said. “So males are usually attached to those females, and they hold on for dear life.”
Easterling said perhaps the most important thing the volunteers will learn is how to properly and safely tag horseshoe crabs.
“The hope is that with those tags in them, if those horseshoe crabs pop up at other beaches, or they're returning to locations, we know that they're hanging around, we know that they're staying in areas, and then we can start to see, how can we maybe protect those areas?
“Are there factors? Are they traveling really long distances? You know, what does that tell us?”
The horseshoe crab's dual role as a critical medical resource and a key part of coastal ecosystems highlights the challenges that sometimes occur when balancing human needs with conservation.
As pressure on the species continues, citizen scientists filling in gaps in our knowledge about their biology and population dynamics becomes all that more important.
Environmental reporting for WGCU is funded in part by VoLo Foundation, a non-profit with a mission to accelerate change and global impact by supporting science-based climate solutions, enhancing education, and improving health.
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