Horseshoes at New Haven Harbor

Arabelle Schoenberg

This summer, the New Haven Land Trust has hosted two Hunting for Horseshoes events at Long Wharf Nature Preserve. In partnership with Sacred Heart University's Project Limulus, the New Haven Land Trust has brought researchers from the program to teach community members about horseshoe crabs and how to catch them and collect data for the Project. 

Horseshoe crabs are amazing animals, because their earliest ancestors came about 450 million years ago. You can go back 200 million years in the fossil record and find animals that look exactly like the modern horseshoe -- these amazing "living fossils" have not significantly changed their anatomy for that long. Horseshoe crabs use copper, instead of iron, to oxygenate their blood and this makes their blood blue. Horseshoe crabs' special blue blood is perfect for testing medications for bacteria, and is used by pharmaceutical companies to test most of the common medications we take. Their blue blood allows them to heal wounds extremely quickly -- even when we found horseshoe crabs with legs or other parts missing, the animals can heal their wounds and go on living for a long time.

Our first horseshoe crab event, Hunting for Horseshoes, took place on the evening of June 2. We had to wait for the tide to come all the way in, and then be on its way out, in order to maximize how many crabs we would find. Jo-Marie Kasinak, one of the head researchers from Project Limulus, brought a team with her who caught horseshoes for us and gave a lecture about the animals. She taught us how to identify the age and sex of each horseshoe crab, and then showed us how to make a small puncture in their shell and tag them, using special research tags from the US Fish & Wildlife Service. 


We all headed down to the beach, and almost everyone found crabs in the shallow waters at Long Wharf Preserve. We tagged around 30 crabs that night, and the team from Project Limulus wrote down all the data to be used for their project. Specifically, they are interested in learning about the migration patterns of horseshoes, which don't seem to have "nesting beaches" like sea turtles, to which they return year after year to breed. Instead, horseshoe crabs seem to stay in and around Long Island Sound, but they might pop up on one beach to mate, and then the next year that same crab will mate somewhere else. 

Participants at the first event strongly requested that we do another, so we held our second event, Horseshoe Crab Tag & Release, on June 20. Adam Rudman, the New Haven beach coordinator for Project Limulus, taught us this time. We caught another 30 crabs, tagged them, and sent them back into the water. 


All in all, this has been a great start to our summer programming at Long Wharf! We look forward to hosting more events throughout the summer. Stay tuned through Facebook or at to learn about the Land Trust's upcoming events! 

Blog Date: 
Wednesday, June 21, 2017