KODIAK, Alaska — The U.S. military has scheduled its exercises in the Gulf of Alaska for the spring, despite calls to move the maneuvers to the fall.

The U.S. Pacific Command’s 2019 Northern Edge exercises, which involve participation from all military services and other agency partners, are planned for May 13-24, the Kodiak Daily Mirror reported Tuesday.

The exercises that are held every other year are expected to involve more than 6,000 service members, 200 aircraft and multiple Navy destroyers and Coast Guard cutters. The exercises allow the military to hone its current abilities and “test future applications of combat operations and weapons capabilities,” U.S. Air Force Sgt. George Maddon said.

Some of the exercises involve live munitions.

Alaska municipalities and preservation groups have opposed the exercises in recent years, citing concerns the event could harm aquatic wildlife and the environment.

The Kodiak Island Borough passed a resolution last year, calling for the training to be moved to after September "when overall marine mammal, fish and migratory bird abundances are lower."

The Eyak Preservation Council based in Cordova has also opposed the event.

"The issues are that explosive munitions and high-powered sonar can impact fish, sea mammals and seabirds, especially at times of the year when migratory species are present," said Carol Hoover, the organization's executive director.

Republican Sen. Lisa Murkowski requested in 2017 for the military to consider moving the 2019 event to the fall.

The Navy's environmental assessment in 2016 determined the impact on fish and marine mammals would be minimal, Maddon said.

"The survey determined most species do not have the capacity to hear sonar," Maddon said, adding that those species that can hear sonar "would need to be very close to the sonar source for a duration of time that is highly unlikely."

Most of the exercises involve flying over the Joint Pacific Alaska Range Complex, Maddon said. The effects from explosives would be contained to where the detonation occurs, he said.

“The impact of explosives within any of these exercises is pretty limited,” Maddon said.