By Mark Rabago, RNZ Pacific Commonwealth of the Northern Marianas correspondent
The United States military has begun the formal environmental review process for the continuation of large-scale training and testing activities in waters around the Northern Mariana Islands and on Farallon de Medinilla.
The Department of the Navy, including the US Navy and Marine Corps, along with the US Air Force, US Army and US Coast Guard, has prepared a draft Supplemental Environmental Impact Statement/Overseas Environmental Impact Statement for the Mariana Islands Training and Testing (MITT) programme.
The proposal would allow military readiness activities to continue at sea and on Farallon de Medinilla, an uninhabited island north of Saipan used as a live-fire training range.
According to the draft document, the activities include joint military training exercises, weapons testing, research and development, and range modernisation.
At-sea operations would occur within the Mariana Islands Range Complex, additional high seas areas north and west of the complex, and nearshore waters of Guam and the Commonwealth of the Northern Mariana Islands.
The study area remains unchanged from the 2020 review. Land-based activities previously analysed on Guam, Saipan, Tinian and Rota are not being re-evaluated in this supplement.
The updated analysis focuses on activities at sea and on Farallon de Medinilla.
Potential impacts
The draft assesses potential impacts on marine mammals, sea turtles, seabirds, fish, marine habitats, cultural resources and socioeconomic uses such as fishing and shipping. It examines the effects of sonar, explosives, vessel activity and other stressors.
The Navy’s modelling predicts most effects on marine mammals would be temporary behavioural changes. A small number of injuries from explosive use are projected for marine species annually, but no population-level impacts or mortalities are predicted.
Three alternatives are analysed: a no-action alternative under which strike warfare training on Farallon de Medinilla would cease; a preferred alternative reflecting a representative year of training activity; and a second action alternative assuming maximum projected activity annually over seven years.
The notice of intent to prepare the supplemental environmental review was issued on 7 June 2025, followed by a scoping and Section 106 consultation period that ran through 22 July 2025.
The draft document was released on 2 March, triggering a public review and comment period that runs until 1 May 2026.
The final environmental impact statement is scheduled for February 2027, with a record of decision expected in mid-2027.
This article is republished under a community partnership agreement with RNZ.
This content originally appeared on Asia Pacific Report and was authored by APR editor.