A New Stingray Species Calls Bermuda Home
Forget unearthing missing planes, shipwrecks, or alien spaceships. For the first time in Bermuda's history, a new stingray species was discovered to call the island its home, according to a recent study . A team made up of local researchers, overseas scientists, fisheries staff, and citizen scientists, have identified the Atlantic cownose ray (Rhinoptera bonasus) as the latest marine inhabitant of this place cloaked in mystery and intrigue. This remarkable migration, as detailed in an in Frontiers in Fish Science, could be linked to changing wind patterns and increased tropical storm activity in the region.
A distinctive species characterized by its dark brown to golden brown dorsal coloration and white underside, the the Atlantic cownose ray possesses lobes on the front edge of its body that give it its unique cownose appearance. Preferring shallow, brackish waters, cownose rays often swim at the surface, reducing the risk of human encounters. And while these rays are equipped with a long, sturdy tail bearing one or two serrated spines with mild venom for defense, they pose little risk to humans. Atlantic cownose rays possess tile-like teeth ideal for crushing crustaceans, mollusks, small invertebrates, and bony fish. They exhibit gregarious behavior, schooling in large groups to migrate great distances, a spectacle cherished by divers and photographers. Listed as "Near Threatened" by the International Union for Conservation of Nature and Natural Resources, these rays have a wide distribution encompassing the eastern and western Atlantic Ocean, including various countries along the coastlines.
The first sighting of this ray in Bermuda dates back to 2012, based on local recollections, with the first photographic evidence provided by a citizen scientist in May 2016 when two individuals were spotted at Mill Creek in Pembroke. Sightings have since increased, with schools of up to a dozen rays reported in the Great Sound and multiple confirmed sightings from October 2022 to October 2023. This prompted researchers from Florida Atlantic University's Harbour Branch Oceanographic Institute, including Dr. Matt Ajemian, to travel to Bermuda for field studies. The team conducted visual surveys from boats in Flatts Inlet and Harrington Sound in October 2022, July 2023, and October 2023, and collected DNA samples to confirm their identity. Interestingly, all the cownose rays observed here have been female, indicating a breeding population in local waters despite their slow reproductive rate of one pup per year. Despite their slow reproductive rate, there is evidence to suggest that these rays are breeding in local waters.
Ajemian, who had previously conducted doctoral research on eagle rays in Bermuda in 2008, says this is a unique opportunity to investigate the cownose ray's impact and behavior. Dr. Robbie Smith, curator at the Natural History Museum of the Bermuda Aquarium, Museum and Zoo believes the first question that should be answered is what is fueling this predator: "There's a big animal that hopped across the ocean, and now it's here and seems to be gaining in numbers — so the first question is, what does it eat?"
While detailed studies on the feeding habits of the cownose ray in Bermuda are still underway, initial observations suggest its diet may closely resemble that of the spotted eagle ray (Aetobatus narinari), Bermuda's sole inshore stingray species until now. Unlike the cownose ray, eagle rays have been spotted on Bermuda's South Shore, feeding on West Indian top snails in areas like Hungry Bay and Devonshire Bay. The resurgence of these snails, which were reintroduced to Bermuda, provides a new food source for eagle rays, potentially influencing their distribution.
It could also influence potential competition between the cownose ray and the spotted eagle ray. To delve deeper into these dynamics, Ajemian has started attaching video devices to eagle rays to gather more data on their behavior and interactions. This technology could offer valuable insights into how these rays utilize their habitats and compete for resources. As Smith pointed out, understanding the behaviors and ecological impacts of these new residents will require ongoing, labor-intensive research. "Perhaps if we're lucky, and [Ajeman] gets another grant," he said, highlighting the need for continued funding and collaboration to fully explore this phenomenon.
The arrival of the cownose ray, Smith believes, underscores the broader environmental changes driven by climate change. "There is change happening in our environment, and we need to keep an eye on it as best we can," he said, noting the possible influence of hurricane activity on the rays' migration, particularly the frequent tropical storms between 2010 and 2012. "That was also a time we had tremendous amounts of Sargassum weed coming here. Did these align in some way?"
"[Answering all these questions will be] very labour-intensive work," he concludes, but expresses hope that support will allow for a deeper exploration of Bermuda's newest resident.
