Sea turtles have returned to forage in Cape and Islands waters and local sea turtle conservationists are asking boaters to be keep an eye out for them and to report their sightings.
Two leatherbacks, the world’s largest species of sea turtle, were the first to be sighted in southern New England waters this boating season.
The first leatherback, spotted last month off Sakonnet Point in Rhode Island, was reported alive and well and swimming slowly on the surface. But the second animal was far less fortunate, washing up a week later at Horseneck Beach in Westport, Mass., gravely injured after being struck by a propeller.
“It was extremely gruesome,” noted Karen Dourdeville, a sea turtle researcher with Mass Audubon’s Wellfleet Bay Wildlife Sanctuary. Sanctuary staff are the responders to dead and stranded sea turtles in southeastern Massachusetts as mandated by the National Oceanic and Atmospheric Administration’s sea turtle stranding network.
Sea turtles are especially vulnerable to vessel strikes when they come to the water’s surface to breathe or to rest. Also, depending on where their prey (jellyfish) are leatherbacks may forage at or just below the surface.
“Even though sea turtles are difficult to see, a careful vessel operator can often see and avoid a sea turtle ahead of their boat,” says Dourdeville.
The Wellfleet Bay Wildlife Sanctuary maintains a website (seaturtlesightings.org) for boaters to report all sea turtle sightings. The site provides photos, videos, and educational tips to aid boaters who may not be familiar with what the four species found here may look like in the water. The website is mobile-device friendly, and sightings can be reported online or by phone, at 888-SEA-TURT (888-732-8878).
Four sea turtle species feed in the waters of southeastern New England in the summer and fall: leatherbacks (the largest in the world and listed as “endangered” under the Endangered Species Act), loggerheads (“threatened”), greens (“threatened”) and Kemp’s ridleys (“critically endangered”).
Leatherbacks exclusively eat jellyfish and are drawn to Buzzards Bay, Vineyard Sound, Nantucket Sound, and Cape Cod Bay due to the summertime abundance of jellies. Loggerheads and Kemp’s ridleys primarily eat crabs and mollusks, and green turtles eat eel grass and other marine vegetation.
In 2018 there were at least 39 stranded leatherbacks in area waters. Of these, at least 15 showed clear evidence of vessel strike.
“The actual number may be higher because some of these were floating carcasses which we couldn’t investigate and limited photos were available to document cause of death,” Dourdeville says. Entanglement with fixed, vertical line fishing gear for the lobster and conch fisheries is another major cause of sea turtle injury and death.
Dourdeville says besides just learning how to look for turtles, boaters are strongly encouraged to refrain from using autopilot.
“Please keep a sharp eye from the helm – autopilots don’t see sea turtles – and remember that we share the water with many species of marine wildlife. Spotting a sea turtle can be exciting and we hope people will make the extra effort to report it!” She says getting photos or videos of the turtles is also helpful for species identification.
The information reported on the website is shared with sea turtle researchers who are working to understand the movements of the animals as well as the dangers they face. “We all have the same goal of wanting to protect and better understand sea turtles in our waters,” Dourdeville says.