BOSTON (AP) — The developer of an offshore wind energy project is partnering with environmental groups on a plan to try to protect the endangered North Atlantic right whale.

The whale is one of the rarest marine mammals. It's thought to number only 411 individuals . The animals travel through New England waters every year.

Vineyard Wind, the Natural Resources Defense Council, the National Wildlife Federation and the Conservation Law Foundation announced an agreement designed to protect the whales on Wednesday.

Vineyard Wind's piece of the agreement involves instituting protective measures while installing and operating turbines as part of a proposed 84-turbine project off Massachusetts.

The developer and the groups say construction will be curtailed in the winter and early spring, which is when the whales tend to visit New England waters.