Navy training and testing could inadvertently kill hundreds of whales and dolphins and injure thousands over the next five years, mostly as a result of detonating explosives under­water, according to two environmental impact statements released by the military Friday.

The Navy said that the studies focused on waters off the East Coast, the Gulf of Mexico, Southern California and Hawaii, the main areas that the service branch tests equipment and trains sailors, from 2014 through 2019.

The studies were done ahead of the Navy applying to the National Marine Fisheries Service for permits for its activities. The Navy said that if it hadn’t done so and was later found to have harmed marine mammals, it would be found in violation of federal environmental law and have to stop its training and testing.

Most of the deaths would come from explosives, though some might come from testing sonar or animals being hit by ships.

Rear Adm. Kevin Slates, the Navy’s energy and environmental readiness division director, said the Navy uses simulators where possible but sailors must test and train in real-life conditions.

"Without this realistic testing and training, our sailors can’t develop or maintain the critical skills they need or ensure the new technologies can be operated effectively," Slates said in a conference call with reporters on Wednesday.

According to the reports, computer models show it might kill 186 whales and dolphins off the East Coast and 155 off Hawaii and Southern California.

The Navy said it developed the estimates by totaling the hours it will test and practice with sonar, torpedoes, missiles, explosives and other equipment over five years. Experts then combine the data with what is known about the marine mammals and then use computer modeling.

Off the East Coast, there could be 11,267 serious injuries and 1.89 million minor injuries such as temporary hearing loss. The reports said the testing and training might also cause marine mammals to change their behavior — such as swimming in a different direction — in 20 million instances.

Off Hawaii and Southern California, the reports said that the naval activities might cause 2,039 serious injuries, 1.86 million temporary injuries and 7.7 million instances of behavioral change.

But Michael Jasny, senior policy analyst at the Natural Resources Defense Council, said the Navy was underestimating the effect of its activities on marine mammals.

For example, he pointed to a study by government and private sector scientists published last month in the journal Proceedings of the Royal Society showing mid-frequency active sonar can disrupt blue whale feeding. The study said feeding disruptions and the movement of whales away from their prey could significantly affect the health of individual whales and the overall health of baleen whale populations.

Jasny said the Navy’s ocean activities are "simply not sustainable."

"These smaller disruptions short of death are themselves accumulating into something like death for species and death for populations," Jasny said.

One of the statements covers Hawaii and Southern California, while the other covers the East Coast and Gulf of Mexico.

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On the Net:

>> Hawaii and Southern California Training and Testing EIS: www.hstteis.com 

>> Atlantic Fleet Training and Testing EIS: www.aftteis.com