Our partners at the Cayman Islands Department of Environment (DoE) recently used REEF data to evaluate Scalloped Hammerhead shark populations in the Cayman Islands, and their findings could mean good news for the future of hammerhead sharks in the area! The Scalloped Hammerhead is a critically endangered shark species with a decreasing global population. They are normally seen in large schools in the Pacific Ocean, but this is a rare sighting in the Atlantic Ocean, and schools of Scalloped Hammerheads have not been observed in the Cayman Islands for decades.

In 2022, DoE's shark research team surveyed the deeper waters off the North Sound, Grand Cayman for the Cayman Deep See Project. Video footage showed a school of Scalloped Hammerhead sharks below 200m - the first sighting around the Cayman Islands since the 1970s! Following this exciting sighting, the team looked at other sources of long-term monitoring data for the Cayman Islands, including the REEF Volunteer Fish Survey Project database, to evaluate population trends. Their findings suggest that Scalloped Hammerhead may be slowly re-occupying the Cayman Islands, selecting and using deeper waters to school. Meanwhile, another species, the Great Hammerhead, has also become less scarce in the Cayman Islands. Results of this work were recently published in the journal Frontiers in Marine Science. For more info and to see all scientific papers using REEF data, visit www.REEF.org/db/publications.