Cycle 4: Second Full Moon of 2026 Monitoring
Night 1:
Two nights before the full moon. We counted 28 total horseshoe crabs on this night, all within the submerged zone. The counts of horseshoe crabs were expected the be low by this point, as we were approaching the end of their peak spawning season.
Night 2:
The night of the full moon. We counted 36 total horseshoe crabs and had one tag recovery! All but one horseshoe crab was seen within the submerged zone.
Please remember that tag recoveries are important for the management of this species, as it helps inform migration patterns of horseshoe crabs. This type of monitoring is reliant on the community to report these tags; if you see a horseshoe crab with a tag, please report it to the US Fish & Wildlife Service!
Daytime Monitoring:
CSHH monitored for horseshoe crabs along the shoreline at North Hempstead Beach Park during the daytime high tide on the day of the full moon. The water was calm, but unusually colored, indicating that there may have been an algal bloom in progress. We counted no live horseshoe crabs, but noted one dead horseshoe crab on the beach near the boom.
Night 3:
Two nights after the full moon. We counted 10 horseshoe crabs, all within the submerged zone. We also saw small baitfish in the shallow waters close to the shoreline.
2026 Monitoring Season Recap:
Across all four monitoring cycles (12 nights) at Tappen Beach, we counted 1,641 horseshoe crabs, tagged 122 horseshoe crabs with US Fish & Wildlife tags, and observed 24 horseshoe crabs that had been tagged previously (all were tagged by us on various dates this season). The highest number of horseshoe crabs counted during a single night was 417, counted during the first full-moon cycle. A total of 26 volunteers participated in the horseshoe crab survey at Tappen Beach.
During our preliminary daytime monitoring at North Hempstead Beach Park, we counted 11 live and 8 dead horseshoe crabs. It was anticipated that there would be less horseshoe crab activity during the day, but it shows that North Hempstead Beach Park is a viable horseshoe crab spawning ground. We also held two educational events with 20 kids.
