The National Marine Fisheries Service (NMFS) has issued a plan aimed at reducing lethal interactions between false killer whales and the Hawaii longline fishery.

Though NMFS is charged with protecting the large dolphins, the Earthjustice law firm has pursued several rounds of litigation aimed at compelling the federal agency to reduce deaths and injuries that its own studies showed were occurring at unsustainable rates.

The take-reduction plan stems from a court-ordered settlement of the most recent lawsuit, which Earthjustice filed on behalf of the Center for Biological Diversity and Turtle Island Restoration Network.

One key provision expands the area around the main Hawaiian Islands where longline fishing is prohibited. Fishers also will be required to use circle hooks that can bend and straighten under the pull of a false killer whale, allowing the animal to free itself from the longline gear.

However, conservationists were disappointed that the Fisheries Service will allow longliners to use a stronger hook than a take-reduction team had recommended.

“In the final plan, the Fisheries Service admits that, the weaker the hook, the more false killer whales will be spared,” wrote Earthjustice attorney David Henkin in an email. “Particularly since the longliners themselves previously agreed to use weak hooks, the agency should not have watered down the rule, putting countless false killer whales at risk of needless injury and death.”

The take reduction plan must reduce false killer whale deaths in the longline fishery to sustainable levels within six months, according to Henkin, and further reduce harm from the fishery to one-tenth that level within five years.