Did you know that horseshoe crabs “donate blood” in a process very similar to that of human donors? The horseshoe crab’s blood, however, is used by the pharmaceutical industry to manufacture a product called Limulus Amoebocyte Lysate, or LAL, that is used to test drugs to ensure that they are bacteria-free.
On Thursday, June 17, at 7:00 p.m., at the University of Delaware’s College of Marine Studies in Lewes, Bill Hall, education specialist with the UD Sea Grant Marine Advisory Service, will discuss LAL and other interesting aspects of the horseshoe crab in the presentation, “Horseshoe Crabs: Man’s Best Friend.” Hall’s lecture is part of the Ocean Currents Lecture Series, which is held monthly at the Lewes campus from April through September.
The discovery of LAL provided a fast, accurate, and humane way to test drugs. This test is now required by the Food and Drug Administration for all injectable and intravenous drugs as well as for screening prosthetic devices such as heart valves and hip replacements.
In addition to being important to human health, horseshoe crabs are vital to the ecology of the Delaware Bay. Every year, during the full and new moons of late May and early June, hundreds of thousands of horseshoe crabs crawl up on the beaches of the Delaware Bay to spawn and bury their eggs.
This mating ritual coincides with the annual spring migration of shorebirds such as the red knot and ruddy turnstone. The shorebirds arrive on the beaches from points in Central and South America to feast on horseshoe crab eggs and “refuel” before they continue on to to their Arctic nesting grounds.
Hall will begin his presentation by going back to the time when horseshoe crabs first appeared on Earth — some 200 million years before the age of the dinosaurs. Although scientists believe that there once were many different species of horseshoe crabs, only four remain today. One species, Limulus polyphemus, is found along the western Atlantic Coast, with the Delaware Bay as the center of the population.
“Various data indicate, however, that the population of horseshoe crabs in the bay is declining,” says Hall. “Fisheries scientists are currently working to protect the crab through research and legislation. The horseshoe crab is the consummate survivor — it has seen the mighty age of the dinosaurs come and go and has lived through numerous ice ages and natural disasters.”
A member of the Marine Advisory Service since 1976, Hall earned a doctorate in education in 1998 from the University of Delaware. He also has a master’s degree in biology from the University of the Pacific in Stockton, California, and a bachelor’s degree in education from Bloomsburg State College in Pennsylvania.
Since 1990, Hall has organized an annual census of spawning horseshoe crabs along the Delaware Bay. In addition, he runs various professional development workshops for Delaware teachers and is the author of several popular bulletins on marine life including the horseshoe crab and the bottlenose dolphin.
The lecture will begin at 7:00 p.m. in Room 104, Cannon Laboratory, at the Hugh R. Sharp Campus, 700 Pilottown Road, Lewes. The hour-long talk will be followed by light refreshments.
While the lecture is free and open to the public, seating is limited and reservations are required. To reserve your seat, please contact the college at (302) 645-4279.