About the Horseshoe Crab Spawning Beach Survey
The Massachusetts Horseshoe Crab Spawning Beach Survey has been conducted since 2008. We use this survey, along with the DMF Trawl Survey and DMF Seine Survey, to monitor the abundance of horseshoe crabs in the state. Unlike the DMF Trawl and Seine surveys, the Spawning Beach Survey is dependent on volunteers and volunteer organizations. Mass Audubon, North and South Rivers Watershed Association, Southeastern Massachusetts Pine Barrens Alliance, U.S Fish and Wildlife Service, Maria Mitchell Association, and the Nantucket Conservation Foundation partner with us for this survey.
Spawning surveys are conducted two days prior, the day of, and two days after the new and full moons of May and June. Surveys start times are based on the time of high tide, which varies by beach. Sixteen beaches from the South Shore, Cape, and islands are surveyed. Most beaches conduct surveys on both day and nighttime high tides. Surveys could occur at 3 in the afternoon, or 3 in the morning, depending on the time of high tide. The number of crabs you will see varies by location and date. The most crabs seen in one survey is nearly 3,000. But there are other surveys where you may not see any crabs. Whether you see 0 crabs, or 3,000, they are all important data points.
The survey is conducted by counting the number of crabs by sex that fall within the survey area. You will need waders or other footwear that you don’t mind getting wet. Data sheets, clipboards, and a thermometer are provided. Volunteers will need a flashlight or headlamp for night surveys. Survey trainings are conducted at most beaches at the beginning of the spawning season.
2025 Survey Dates
- Saturday, May 10th
- Monday, May 12th
- Wednesday, May 14th
- Saturday, May 24th
- Monday, May 26th
- Wednesday, May 28th
- Monday, June 9th
- Wednesday, June 11th
- Friday, June 13th
- Monday, June 23rd
- Wednesday, June 25th
- Friday, June 27th
Survey locations
Survey locations table
| Site # | Beach | Site # | Beach |
|---|---|---|---|
| 1 | Duxbury | 9 | March 2-3 |
| 2 | Long Beach | 10 | Erica's Beach |
| 3 | Millway | 11 | Stage Harbor |
| 4 | Long Pasture | 12 | Bass River |
| 5 | Sanctuary Beach | 13 | Monomoy Beach |
| 6 | Indian Neck | 14 | Warren's Landing |
| 7 | Great Island | 15 | Tashmoo |
| 8 | Priscilla's Landing | 16 | Swifts Beach |
Compliance reports
Horseshoe crabs are managed at the interstate level by the Atlantic States Marine Fisheries Commission (ASMFC). Each year member-states, including Massachusetts, must submit a compliance report to ASMFC documenting the status of the fishery and show that the horseshoe crab population is being monitored and managed properly. To view an annual report, click on the links below.