A federal suit brought by environmental nonprofit Natural Resources Defense Council seeks to redress the problem by holding defendants Secretary of Commerce, National Oceanic and Atmospheric Administration, and National Marine Fisheries Service responsible for designating a critical habitat for the whales.

The Endangered Species Act requires critical habitat designation within a year of species listing, and "not more than one additional year" if critical habitat is not determinable. The extension expired more than 2 ½ years ago, according to the complaint filed in U.S. District Court for the District of Columbia on July 13.

"False killer whales are a member of the dolphin family and are generally found in the open ocean where they prey on fish and squid," the group says in its complaint. "The main Hawaiian Island insular false killer whales, however, are a distinct population that lives close to land and, rather than migrate through the open ocean like others of their species, are permanent island residents.

"Over a decade of aerial surveys have shown a dramatic decline in the animals' abundance, and the best estimates put the population at fewer than 150 individuals," the group continues. "Although the absolute abundance of Hawaiian insular false killer whales is small, location data collected from satellite tags deployed on the whales has confirmed that they concentrate in select areas around the main Hawaiian Islands and their population density is among the highest of any false killer whale species."

The group first petitioned the Secretary of Commerce and the National Marine Fisheries Service to list the animals as an endangered species and designate critical habitat on Sept. 30, 2009.

On Nov. 17, 2010, the defendants issued a finding that the whales are "in danger of extinction throughout [their] range," and proposed to list them as endangered.

Despite the finding, the government did nothing and the environmentalists sued in Federal Court in May 2012, accusing the feds of being out of compliance with Endangered Species Act provisions requiring the secretary to issue a final rule within a year of the finding.

In a final rule that went into effect on Dec. 28, 2012, based in part on updated information provided by Natural Resources Defense Council's tracking of the whales, the government agreed to list the whale population as endangered — but concluded that critical habitat could not be determined at the time because they lacked sufficient information on the impacts of designation, the geographical area occupied by the species, and the physical and biological features critical to conservation.

"That decision is now overdue," the environmental group says in its complaint.

"Hawaiian false killer whales can't wait," said Giulia Good Stefani, a staff attorney with the Natural Resources Defense Council's Marine Mammal Protection Project. "The species is in grave danger of going extinct because of this delay. Their survival depends on getting their habitat — their home, really — protected. It's past time for the government to step up and fulfill its duty."

Of 29 separate threats to the species, several have been found to be habitat-related: reduced prey from overfishing, injury and mortality from fishing gear, toxic contamination and anthropogenic noise.

"Fisheries enter the whale's habitat and threaten the species by overfishing stocks the whales depend on for food and injuring the animals with active or derelict fishing gear," the group says in its complaint.

"Persistent organic pollutants in the water are a threat to the whale's reproductive and immune systems; a recent study found pollutants in 9 out of 10 samples taken."

Additionally, the group says in its complaint that "the U.S. Navy has a range complex around Hawaii that employs mid-frequency sonar and explosives, for training and testing purposes, in an area encompassing the most of the whales' known range that could cause injury, stranding, habitat displacement, and disruption in essential behaviors such as foraging and communication between mothers and calves."

The group seeks a declaration that the government failed in its duty to designate critical habitat for the whales and an order requiring the agencies to do so by a specific date.

In-house counsel Jared E. Knicley, Rebecca J. Riley, and Giulia Good Stefani are representing the group in the action.

A spokeswoman for the National Oceanic and Atmospheric Administration Fisheries said in an email that the agency is "presently drafting a critical habitat designation for the main Hawaiian Islands insular false killer whale distinct population segment."

In an email, a Natural Resources Defense Council spokeswoman noted the world's navies are currently bombarding the whales' habitat with noise during the RIMPAC naval exercises in the waters around Hawaii.

"RIMPAC is the largest multinational naval exercise in the Pacific Ocean and one of the largest in the world. During the 2004 exercise, RIMPAC nearly caused the deaths of some 200 melon-headed whales, which stranded in Hanalei Bay as sonar blared offshore; and all of that activity is likely impacting false killer whales and Hawaii's other small, resident whale and dolphin populations as we speak," the spokeswoman said.