In late July there was a manatee sighting off the coast of Cape Cod. It was a rare occurrence but one we could be seeing more of as few areas see change in water temperature as dramatically as New England.

According to Tufts University, the Gulf of Maine, which stretches from Cape Cod to Nova Scotia, is one of the fastest-warming oceanic areas on Earth with a warming rate about three times faster than the average ocean temperature.

John Durbin, a senior scientist with the Anderson Cabot Center for Ocean Life at the New England Aquarium, says those rare sighting are becoming more common.

“Just about every day, we’re hearing about unusual sightings, species of say tropical fish that are being brought up by the Gulf Stream and settling here and really large animals that are obvious and easy to see like manatees and increased sightings of sharks,” Durbin says.

Durbin points out that since warming waters are habitable to different types of creatures, the local ecosystem is changing.

“Those species we’ve come to associate with New England, like Atlantic cod are shifting northwards into deeper and cooler water. Even lobster, we’re seeing those declines in the southern part of the Gulf of Maine and southern New England.”

Larger creatures are seeing habitat shifts, too. “The biggest impact on whales is on our critically endangered North Atlantic right whales that feed on small plankton that like cold water. Those plankton are just moving further and further north.”

In addition to causing migrations, the warmer water has also impacted the behavior of longtime residents of the Gulf of Maine, such as great white sharks. “Although they can generate their own heat, they’re ectothermic, they use the heat of the water. So when the water’s warmer, they’re more active. They need to eat more, their metabolism’s higher,” says Durbin.

He also adds that factors, such as federal protections for seals, have also contributed to a rise in local great white populations.

Since these ecological changes are happening slowly and systemically, Durbin says that despite uncertainty about the climate’s future, he believes that many newly arrived species will become established in local waters. “Those changes that are slow and big and are going to rumble on. I think it is a fair assumption that some of these unusual visitors are going to become at least seasonal residents — while we still have cold water in the winter.”