The Navy is seeking public comment on a new environmental impact statement for future training and research, including sonar that might harm whales and dolphins, in what’s known as the Hawaii-Southern California Training and Testing Study Area.

The Hawaii Range Complex, which is part of the study, encompasses about 2.7 million square nautical miles of ocean around the Hawaiian Islands.

But also to be examined for training beyond 2018 are areas where sonar testing could occur during vessel transit between the Hawaii and Southern California range complexes; a “temporary operating area” north and west of the Hawaii Range; and pierside, port and harbor locations.

The Center for Biological Diversity said the move follows a March 31 federal court ruling that the Navy illegally failed to consider restricting military exercises in biologically important areas.

“The Navy doesn’t need continuous access to every square inch of the Pacific. It’s a big ocean, and we need protections for the places that are important to the survival of whales and dolphins,” Miyoko Sakashita, oceans program director for the center, said in a news release.

A five-year Navy training plan underway since 2013 was overturned after a legal challenge by Earthjustice, representing the Conservation Council for Hawaii, the Animal Welfare Institute, the Center for Biological Diversity, and Ocean Mammal Institute.

The Navy was permitted to test and train even if it ended up “harming a stunning number of marine mammals,” a federal court judge determined.

In a September settlement the Navy agreed to make important habitat for numerous marine mammal populations off-limits to midfrequency sonar training and testing and the use of powerful explosives during the remainder of the current five-year plan, which expires in December 2018, the Center for Biological Diversity said.

The new environmental impact statement will consider the effects of Navy training and testing after 2018 while accommodating evolving mission requirements including new ships, aircraft and weapon systems.

“The science is clear. To avoid permanent injuries and death to whales, dolphins and other marine mammals, it is vital to keep Navy sonar and explosives out of the areas these animals need for essential activities like feeding, resting and caring for their young,” said Earthjustice attorney David Henkin. “When it voluntarily agreed to the settlement, the Navy made clear that it can both perform its mission and stay out of important marine mammal habitat.”

The Navy is seeking public comment and concerns to shape the new EIS by mail and through the website hstteis.com. Mailed comments must be postmarked by Jan. 16. Informational meetings also will be held Dec. 3 at Island School Main Hall on Kauai and Dec. 5 at Keehi Lagoon Memorial on Oahu.

“We urge the public to get involved and tell the Navy its new study needs to examine ways to keep destructive training out of vital marine mammal habitat,” Marjorie Ziegler, executive director of the Conservation Council for Hawaii, said in a news release.

Lt. Cmdr. Matt Knight, a spokesman for U.S. Pacific Fleet, said the Navy “seriously considers impacts to marine mammals when evaluating its activities.” At the same time, training and testing “are essential,” he added.

“The key to ensuring national security, maintaining freedom of the seas and avoiding tragic loss of life is to ensure that sailors receive realistic training that fully prepares them to be prepared to fight, and that the equipment they rely on is thoroughly tested prior to use,” Knight said in an email. “This is more critical today than ever.”

More than 40 nations have modern, extremely quiet submarines, and active sonar is the most effective means available for detecting and tracking them, he noted.

“Sonar detection is a highly complex and perishable skill that requires constant honing in a variety of locations and cannot be fully mastered with simulators,” Knight said. Failure to detect and defend against such a threat cost the lives of 46 South Korean sailors when the frigate Cheonan was sunk by a North Korean submarine in March 2010, he said.

Whenever the Navy trains or tests with active sonar or the types of explosives analyzed in the previous EIS, it employs protective measures including lookouts for marine animals, reducing power or halting active sonar when marine mammals get within a predetermined safety range, and establishing safety zones around detonations, Knight said.

After a federal judge ruled against the Navy in late March, the service “faced the real possibility that the court would stop critically important training and testing,” Knight said.

Instead, the National Marine Fisheries Service and Navy negotiated with the plaintiffs over five months to reach agreement, he said.

Among those agreements, the Navy is prohibited from using midfrequency active sonar and explosives on the eastern side of Hawaii island and north of Molokai and Maui, protecting Hawaiian monk seals and small populations of false killer whales and Cuvier’s beaked whales, Earthjustice said.

“The settlement allows critical testing and training activities to continue in the (Hawaii-Southern California training areas) but increases restrictions on the use of active sonar, live munitions and speed protocols in select areas,” Knight said. “The Navy needs to continue to test and train in diverse environments, many of which replicate real-world operating areas. It is essential to military readiness that we maintain this flexibility.”