For the first time in the island’s history, a new stingray species has settled in Bermuda, according to a study by overseas scientists working with local researchers, fisheries staff and ordinary citizens.

An article in Frontiers in Fish Science states that the migration to Bermuda of the Atlantic cownose ray, Rhinoptera bonasus, which feeds on clams and crustaceans, could have been prompted by shifting wind patterns as well as heightened tropical storm activity in the region.

Robbie Smith, curator at the Natural History Museum of the Bermuda Aquarium, Museum and Zoo, was among contributors.

Dr Smith said: “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?”

Although the newcomer’s feeding has yet to be studied closely, Dr Smith said researchers suspected its food of choice was likely “the exact same diet” as that of the spotted eagle ray, previously the island’s only inshore stingray species.

Eagle rays have “historically always fed on the bottom — they are major predators of calico clams, mussels, oysters living on the bottom”.

Dr Smith said that while much remained to be learnt about the behaviour of the cownose ray, the research was important given the increasing impact of climate change.

“There is change happening in our environment, and we need to keep an eye on it as best we can.”

Researchers from Florida Atlantic University’s Harbour Branch Oceanographic Institute hailed the finding as a first in the centuries of human habitation in Bermuda.

The scientists said people in Bermuda recalled seeing the new rays in Bermuda as early as 2012.

The article said they have been seen “across most of the island's protected coastal waters but not on the exposed South Shore”.

The first photographs came from a “citizen scientist” in May 2016, when two rays were sighted at Mill Creek in Pembroke.

Within months, schools of up to a dozen rays were reported in the Great Sound, and 14 sightings were reported from October 2022 to October 2023.

Scientists conducted their own visual surveys in October 2022, July 2023 and October 2023 from a slow-moving boat circling through Flatts Inlet and Harrington Sound.

They also collected DNA samples.

It marked a return to the island for Matt Ajemian, of FAU, whose doctoral research into eagle rays brought him to Bermuda, and to BAMZ in 2008 to study eagle rays, a close relative of the cownose.

The connection between the species was of interest because cownose rays were increasing in number on the United States East Coast, potentially posing a threat to fisheries such as the North Carolina scallop industry.

All the cownose rays studied in Bermuda were female, but the fish appear to have bred in local waters — although they reproduce slowly, producing one pup per year.

The fish have a stinger to defend themselves, but pose little risk to humans.

Dr Smith said: “It seems pretty clear that they’re coming here from the US East Coast.”

Hurricane activity may have prompted the migration, he said, noting the frequency of tropical storms between 2010 and 2012.

Dr Smith added: “That was also a time we had tremendous amounts of Sargassum weed coming here. Did these align in some way?”

He said many questions remained about the cownose ray, including whether it might compete with the spotted eagle ray.

Cownoses have not been seen on the South Shore, but eagle rays have appeared there, feeding on West Indian top snails in sheltered waters such as Hungry Bay in Paget and Devonshire Bay.

The endangered snail, reintroduced to Bermuda, has rebounded in numbers, presenting a new food source for a different species.

Dr Ajemian recently began attaching video devices to eagle rays to learn more of their behaviour.

Dr Smith said the island would be fortunate to get a chance to delve deeper into the lives of its new cownose residents.

“It’s very labour-intensive work,” he said. “Perhaps if we’re lucky, and Matt gets another grant.”