The U.S. Navy is encouraging the public to send in comments about its plan to intensify undersea training in the western Pacific and increase bombing of a tiny uninhabited island north of Guam.

The Navy has been training troops and testing new technologies in the waters around the Mariana Islands for decades, and Farallon de Medinilla has been a target island since 1971. The Navy says that the training and testing in the region is “critical to maintain readiness.”

But there’s relatively little known about the whales and dolphins that live in the region, and environmentalists fear the Navy is underestimating harmful effects of its use of sonar and explosives.

Courtesy of Department of Defense

The Navy announced Tuesday in the Federal Register that it will prepare what’s called a supplemental environmental impact statement that will include new information like “an updated acoustic effects model, updated marine mammal density data, and other best available science.”

The public has until Sept. 15 to comment and can do so at the website for the project, which is known as the Mariana Islands Training and Testing or MITT.

The draft supplemental environmental impact statement isn’t expected to be released until the fall of 2018. That’s when there will be a round of public hearings and additional comments. The final document won’t be out until spring 2020, with a final decision expected that summer.

David Henkin, an attorney for the nonprofit environmental law firm Earthjustice, said the new study makes him cautiously optimistic that the Navy is making an effort to fill information gaps and do a better job of analyzing the impact of its activities.

The notice says the proposed training and testing is “generally consistent” with what the Navy suggested in its last analysis. But one section of the Federal Register notice raises questions about whether the Navy could ramp up its training and testing in light of tensions with China and North Korea.

This map shows where the Department of Defense plans to increase training and testing in the Marianas. The locations are estimates and the plans shown aren’t exhaustive. Use the buttons in the top-right corner to zoom in and out on the map, and click on the arrows in the top-left corner to make the map full screen. Click on “Map Controls” in the top-left corner to learn more about navigating the map.

The supplemental analysis will “propose changes to the tempo and types of training and testing activities, accounting for the introduction of new technologies, the evolving nature of international events, advances in war fighting doctrine and procedures, and changes in the organization of vessels, aircraft, weapon systems, and military personnel,” the notice says.

“The jury is still out about what that means about whales, dolphins and people who are concerned about their well-being,” Henkin said. “It’s early to really know what they’re up to but we’re going to be very carefully monitoring the situation.”

The MITT is one of several military plans to increase training on and around the Marianas, a chain of 15 islands in the western Pacific made up of Guam and the U.S. Commonwealth of the Northern Mariana Islands.

The Air Force is in the process of establishing an airfield on the island of Tinian and the Navy is preparing to create a Marine Corps base on Guam.

The Navy also wants to set up a bombing range on the island of Pagan and establish an artillery range on Tinian despite potential destruction of historic sites and damage to Tinian’s aquifer.

Henkin filed a lawsuit on behalf of local community groups against the relocation of Marines to Guam and the plans to increase training on Tinian and Pagan. He said the next status conference for the case is scheduled Aug. 25, and the court may rule on the Navy’s motion to dismiss.

Click here to read an in-depth series on the military’s plans for the region.