From the South Carolina Department of Natural Resources
If you’ve ever encountered the domed shell of a horseshoe crab, chances are it was on a sandy beach.
Until recently, beaches were believed to be the only places where horseshoe crab eggs could hatch and grow. But three years ago, South Carolina Department of Natural Resources biologists discovered that salt marshes might have an unexpected importance to these ancient invertebrates, offering alternate habitat where eggs and hatchlings can thrive.
Now the same research team, in collaboration with researchers at Sacred Heart University and Plymouth State University, has shared new findings confirming that American horseshoe crabs regularly spawn in salt marshes – not just in South Carolina but across the Atlantic coastline. The research was published recently in the peer-reviewed journal Frontiers in Ecology and the Environment.
“While horseshoe crabs would occasionally be observed spawning in marsh areas, that behavior was always thought to be rare,” said lead author and SCDNR scientist Dr. Daniel Sasson. “This study shows that spawning in marshes is more common than we ever thought and seems to happen across much of their range.”
Horseshoe crabs are marine arthropods that have inhabited the planet for millions of years. Despite the name, they are more closely related to scorpions than to crabs. Horseshoe crabs play a critical role in the coastal ecosystem and human health: By digging up sediment during spawning, they add nutrients to the water column; their eggs are an important food sources for tens of thousands of shorebirds making long migrations; and a compound in their blood is collected and used to detect contamination in vaccines and medical devices.
Horseshoe crabs spend most of their lives at sea. But every spring, adult horseshoe crabs from Maine to the Yucatan Peninsula scuttle ashore under new and full moons to spawn – or lay eggs.
It was in South Carolina that researchers first found healthy horseshoe crab eggs, embryos and hatchlings in s
