Horseshoe crabs (Limulus polyphemus) were once found in the Pensacola Bay System and then disappeared. The first thought to the cause of their decline would be the decline in water quality and/or loss of habitat. These ancient creatures, which resemble armored stingrays but are actually related to spider and scorpions, plow through the sediments of both the estuaries and the open Gulf searching for invertebrates to feed on.

But in the spring and fall of each year, they move into the bays to seek mates and beaches for the breeding season. Females are much larger and approach the beach during the spring high tides of the spring and fall to lay their eggs at the wash zone of the sandy beach. The smaller males use a modified appendage that looks like a hook to hold on to her and “rides her back” into the beach as well. Many times, several other males will follow the pair to the shore, these males are known as satellites. Once she begins to lay her eggs, all the males compete to fertilize them with their sperm. The developing young remain in the sand until the next spring tide arrives, at which time they hatch.

It is exciting to see the return of these creatures to our bay and give sign that maybe things are improving here. We are looking for citizen science volunteers to walk potential nesting beaches during the months of October, November, and December searching for nesting activity. If you are interested in participating you can contact Escambia County Sea Grant Agent Rick O’Connor to sign up for one of the beaches, a list of spring high tides for the 2021 fall season, a copy of the data sheet, and a short training on what to do and how to do it. You can contact Rick at roc1@ufl.edu. More than one volunteer can survey the same beach.

Beaches to Be Surveyed

Spring High Tides (based on time at Ft. McRee)

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