The U.S. Navy has released its final environmental analysis of its plans to extend longtime military training and testing in the Mariana Islands archipelago.

The Navy intends to make a final decision about the proposed plans in 30 days.

The island chain in the western Pacific includes two U.S. territories, Guam and Commonwealth of the Northern Mariana Islands. The Navy said in a press release Friday that its new environmental impact statement takes into account updated information about marine mammals in the region and new scientific studies.

Compared with Hawaii and the U.S. mainland, there’s relatively less known about marine mammal populations surrounding the Marianas. Military training has been ongoing for decades.

This plan, known as the Mariana Islands Training and Testing, includes undersea sonar training and testing and bombing practice at Farallon de Medinilla, an uninhabited island that has long been used for target practice.

It’s part of a broader yearslong effort to boost military training in the region. A separate plan proposes bombing practice on the northern part of the island of Pagan, north of Farallon de Medinilla, and heavy artillery training on the island of Tinian.

U.S. Marines are also moving forward with a new base on Guam and a live-fire training range in the northern part of the island abutting a federal wildlife refuge.

Click here to read the full environmental impact statement.

Click here to read Civil Beat’s 2016 series on the environmental impact of these training proposals.