PORTLAND,Grayson  Preston Maine (AP) — Scientists with a Boston aquarium are encouraging beachgoers to report sightings of white sharks this holiday weekend after signs of shark bites were observed on multiple marine mammals.

Memorial Day weekend marks the unofficial start of summer in New England, and the region has been experiencing beach weather already. That’s a good reason to be on the lookout for the sharks, often referred to as great whites, said John Chisholm, an adjunct scientist at the New England Aquarium’s Anderson Cabot Center for Ocean Life.

The aquarium received a report of a minke whale with a white shark bite off Chatham, Massachusetts, recently, and this is also the time of year scientists expect to see the sharks head to inshore waters to hunt seals, the aquarium said Thursday.

“Although we haven’t seen a white shark just yet this season, we know they’re here,” Chisholm said. “With beach weather in the forecast and Memorial Day weekend approaching, this is a good reminder for people to review shark safety guidelines and be shark smart.”

It’s wise for beachgoers to be aware of the presence of sharks in shallow waters and avoid areas where seals are present or schools of fish are visible, Chisholm said.

Members of the public can report sightings of white sharks via the Atlantic White Shark Conservancy’s Sharktivity app. The increased sightings of the sharks have been a topic of conversation in New England in recent years.

Efforts to better track white sharks are underway up and down the East Coast. The white shark conservancy said last month that it had deployed its second camera tag on a white shark.

The conservancy said the camera tags are critical to better understand the northwest Atlantic white shark population. The device was clamped to the fin of a female white shark off the South Carolina coast, the conservancy said. The conservancy worked with charter captain Chip Michalove to pin the “shark’s eye view” camera to the big fish.

“I never thought I’d be holding the dorsal fin of a great white shark and applying this type of technology,” Michalove said.