Horseshoe Crab Egg-stravaganza!

The full moon rose over the Delaware Bay as we drove to our destination beach. We arrived later than I had hoped — the moon was high over the water already. No matter, the horseshoe crabs we moving and the kids were able to see what the big deal was. Large females were crowded by many males vying to disperse their genetic materials for future generations. Hundreds of these ancient creatures came ashore at high tide, the best time for the females to lay their eggs at the highest point on the beach with the least effort. Researchers showed the kids how to count the creatures using a standard grid technique. Most of the students had never seen horseshoe crabs and they were incredibly enthusiastic!

Most scientists agree that the basic design of the horseshoe crab has been around for about 445 million years. However, the Delaware Bay breeding phenomena has only been around less than 10,000 years — there was no bay before then!

The incredible link between the crabs and four species of shorebird has been a hot topic in recent years. Ruddy Turnstones, Sanderlings, Semipalmated Sandpipers and especially Red Knots depend upon the protein-rich crab eggs to nourish them on their journey north to breeding grounds on the tundra. In recent years, the crabs numbers have been dropping. So have the shorebirds’.

Fishermen, collecting the crabs for bait, claim there is an unending supply. Similar thinking led to extinction of the Passenger Pigeon. Pick-up trucks and fishing boats are piled high with crab carcasses to be stripped of their meat and tossed aside, eggs and all. Few regulations are in place to protect the crabs.

Horseshoe crabs are more important than many realize. Prepared properly, their blood has amazing properties for detecting bacteria in vaccines and other medical supplies. What once took days to learn using previous methods can now be much more accurately checked in about an hour!

photos © Kevin Loughlin