In this March 28, 2018, file photo, a North Atlantic right whale surfaces in Cape Cod bay off the coast of Plymouth, Mass. Credit: Michael Dwyer / AP

A group representing Maine lobstermen sued the federal government on Monday, arguing that new regulations aiming to protect endangered right whales ignore scientific data and will cause “devastating economic hardship” for those working in the lobster industry.

It is the latest front in a longstanding battle over the regulations, which have been in the works for several years. The final rules prohibit lobster fishing in a 967-square-mile swath of the Gulf of Maine between October and January. They also require the use of weaker ropes so whales that become entangled can break free more easily and reduce the number of rope lines that fishermen can use to link buoys to lobster traps.

Environmentalists have argued that the changes are necessary to reduce the threat to the North Atlantic right whale, which has seen its numbers dwindle in recent decades, with fewer than 400 individuals remaining, according to the National Oceanic and Atmospheric Association. But lobstermen say the rules are unnecessary, noting there are few recorded cases of right whales becoming entangled in the waters where Maine fishermen work.

The lawsuit, filed in the U.S. District Court for the District of Columbia by the Maine Lobstermen’s Association, alleges that the National Marine Fisheries Services’ biological study that was the basis for the regulations is based on flawed data. The survey, the lawsuit argues, attributed right whale deaths to the Maine lobster industry that were actually caused by other fisheries or by non-fishing boats that collide with the endangered whales.

“The science does not support the agency’s plan. Using worst case scenarios that hold Maine lobstermen accountable for right whale deaths occurring in Canada won’t help protect right whales, but it will decimate Maine’s lobster industry,” Patrice McCarron, executive director of the Maine Lobstermen’s Association, said in a statement.

Following the regulations will pose financial challenges to thousands of Maine lobstermen, the suit argues, resulting in “needless economic dislocation.” It asks the court to find the biological survey that the rules were based on violated federal law.

Maine’s elected officials have been united in opposing the rules. Gov. Janet Mills wrote a letter to U.S. Secretary of Commerce Gina Raimondo last week asking the agency to delay implementing the portions of the rule that require lobstermen to update their gear, saying it could cost the industry $30 million in the next year.