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Horseshoe Crabs

The Maryland Coastal Bays Program assists the Maryland Department of Natural Resources in conducting annual horseshoe crab surveys to measure spawning abundance in the Coastal Bays. The survey has been in existence since 2002 and provides valuable data used in fisheries management. Surveys start in late May and continue through early July, with sampling taking place once every two weeks.

The surveys are conducted during these months as it is peak spawning (mating) season, and they occur on evening high tides during full and new moons. During high tide events, horseshoe crabs are able to easily navigate obstacles, such as rocks, while spawning. However, when tides recede, these obstacles are no longer navigable causing many horseshoe crabs to become stranded. As a result of the high number of stranded horseshoe crabs seen at several locations over the years, MCBP started the Stranded Spawning Horseshoe Crab Recovery Team. A community science initiative whose goal is to routinely check hotspot spawning locations to rescue stranded or flipped horseshoe crabs throughout the spawning season. This volunteer program helps prevent mass casualties and allows us to better understand stranding patterns throughout the Coastal Bays. People who are interested in learning more about this program can watch this training video link HERE

If you are interested in volunteering for the horseshoe crab survey please contact Carley Toulan  at

If you are interested in becoming a Stranded Spawning Horseshoe Crab volunteer for the 2024 spawning season, click on the link HERE.

To learn more about the significance of the Horseshoe Crab click onto the annual reports and check out the links below.




Horseshoe Crab Anatomy

Horseshoe Crab Brochure

And if you want to participate in community science projects to monitor our Horseshoe Crabs, you can report sightings and also if you find a Horseshoe crab that was tagged:

To report sightings click HERE

To report tagged Horseshoe Crabs, click HERE

Contribute Online

Become a member of the Coastal Bays Foundation and donate online securely through PayPal. Your financial contribution will go toward protecting our watershed, its habitat, and wildlife. The Maryland Coastal Bays Program Foundation is a 501(c)(3) nonprofit; all donations are tax deductible.