Maine fishing gear is being blamed for the death of an endangered right whale that washed up on Martha’s Vineyard in January.

According to CBS 13 News, federal biologists say the cause of death of the female whale was chronic entanglement. The gear that was found wrapped around the whale had the purple markings Maine lobstermen use on trap and buoy lines.

The Maine Lobstermen’s Association issued a response, saying in part, “This is the first reported entanglement of a right whale in Maine lobster gear in 20 years and the first death attributed to the fishery.”

Maine lobstermen have fought recent federal regulations aimed at protecting the endangered whales.