Horseshoe Crab Monitoring

Juvenile Horseshoe Crab

Peconic Baykeeper partners with the Long Island Horseshoe Crab Monitoring Network  help monitor current populations of this imperiled species.  Hosted by the Cornell Cooperative Extension, this program monitors important spawning sites for horseshoe crabs (Polyphemus limulus) throughout coastal New York. Having survived relatively unchanged for hundreds of millions of years, these “living fossils” are becoming less abundant throughout Long Island as they face threats from commercial harvesting and habitat loss from coastal development. Horseshoe crabs play a vital role in the health of our marine ecosystems as “keystone species” with their eggs being an important food source for threatened and endangered migratory shorebirds and other wildlife. Horseshoe Crab blood is also an invaluable tool to the pharmaceutical industry as it has clotting properties that identify contamination quickly and effectively.


2022 Monitoring Program

Peconic Baykeeper will be partnering with the South Shore Estuary Reserve to monitor a known spawning site for Horseshoe Crabs off Meadow Lane in Southampton, NY with counting and tagging activities taking place during full and new moon tides from May to July. Data generated from the survey will be used to drive better management for this species including advancing coastal conservation. For more about this program, click here!


How Can You Get Involved?

We will be accepting volunteers in 2022 with surveys taking place from mid-May to mid-July around full and new moons. Reach out to to learn more.  You can also report your sightings of adult breeding horseshoe crabs (paired or grouped) to Peconic Baykeeper at Please include the exact location of your sighting so that we can work with our partners to identify new sites for intensive monitoring in both the Peconic and South Shore Estuaries.