With a recent cold snap ending a period of unseasonably mild weather, dozens of scup have washed up dead on the shores of Lagoon Pond.

Oak Bluffs shellfish constable David Grunden said between 35 and 100 of the fish have been found along the pond, mainly clustered around the shoreline by Lagoon avenue in Oak Bluffs. He suspects they were killed by the cold water.

Scup, also known as porgy, is a migratory species, often spending time in coastal areas of Massachusetts from May to October. After that most fish swim to deeper offshore waters or migrate south. According to the Department of Marine Fisheries, scup prefer water temperatures greater than 45 degrees Fahrenheit, and are most often found in 55 to 77 degree waters. Plunging water temperatures in the early fall have killed large numbers of the fish in the past.

Derek Nagengast, an Oak Bluffs resident who lives near the Lagoon, said he noticed the dead scup washed up on shore on Wednesday afternoon, visible every few feet along the shoreline.

By Thursday morning Mr. Grunden had also heard about the scup. He headed down to the pond to survey the scene and take pictures.

“The most likely thing right now is that they stayed in the pond too long and the cold snap killed them,” Mr. Grunden said. “It’s unusual for them to be here even past November,” he added.

Mr. Grunden said he placed calls to the Department of Marine Fisheries and other fish experts to find out more information but had yet to hear back.