An FA-18D Hornet and a U.S. Navy MH-60S Knighthawk helicopter receive fuel on West Field on Tinian during simulated surge operation as part of Exercise Forager Fury 2012. The Navy and the Marines are exploring the possibility of expanding training opportunities in the region.

CAMP FOSTER, Okinawa — The U.S. may soon test new weapons systems and host more joint exercises with allies in a vast western Pacific training ground, but the plans depend at least partly on the concerns of local islanders.

Both the Navy and Marine Corps are floating proposals to expand training around the Northern Mariana Islands, which were strategically valuable during World War II and are again gaining attention as the United States pivots toward Asia, at least partly as a counterweight to China.

The Navy wants to conduct more anti-submarine training with its new littoral combat ships. The Marine Corps wants space to practice unit and mixed unit tactics with allies such as Japan while using real bullets and bombs.

But the islands comprise a U.S. territory and commonwealth, so federal law requires the services to consult residents of Guam, Saipan, Tinian and Rota. The military plans unveiled this year will require the federal government to renew permission for the Navy to hurt or kill protected sea mammals and have already raised some concerns over the effects of bombing on a sparsely inhabited island called Pagan, which the Marines want for a practice range.

“The Navy is evolving, and we have new weapons platforms coming onboard,” said John Van Name, a senior environmental planner for the U.S. Pacific Fleet and project manager for the Navy’s study on the potential environmental effects of new training.

The fleet’s newly introduced littoral combat ships are now operating in the region and need to be able to conduct anti-submarine exercises around the Mariana Islands to combat new types of ultra-quiet subs used by China and others, Van Name said.

The Navy may also dramatically expand its training footprint and increase the amount of some live-fire exercises, according to the environmental impact statement it released to the public earlier this year.

The scope of training could increase from the existing 497,469-square-mile Mariana Islands Range Complex to a larger 984,601-square-mile study area, pushing operations much farther west toward the Philippines and Okinawa. The tempo may also go up — for example, air-to-ground bombing exercises could double from 1,300 to 2,520 per year and gunnery exercises between ships could increase from 17 to 240 annually.

Meanwhile, the Marines are looking at more amphibious vehicle landing sites, air-to-ground ranges, landing and drop zones, and training sites large enough to accommodate bilateral training missions.

“Marines make do with our pre-existing training sites to maximize our readiness, but the need to fairly identify gaps in our training capability and solve them is a vital and continuing process to maintain and improve our readiness. These new sites proposed for [the Commonwealth of the Northern Mariana Islands] are needed,” said Maj. Neal Fisher, the public affairs officer with Marine Corps Activity Guam.

In 2012, the U.S. and Japan announced they would pursue increased joint training in the CNMI, which includes Saipan, Tinian and a string of other islands.

The Marines studied the area and concluded that Tinian and the small, mostly uninhabited island of Pagan could meet all its training needs. Tinian was taken by Marine forces from the Japanese during World War II and became an important staging ground for the U.S. war effort. It is still home to a number of U.S. training areas, which the Marines hope to expand.

The Marines are also proposing to create a training range by leasing the entirety of Pagan, a U.S. territorial island that sits in the northern CNMI and shares about 10-25 semi-permanent residents with two neighboring islands, according to a U.S. Fish and Wildlife survey in 2010.

The proposed range on Pagan is separate from the planned relocation of about 4,800 Okinawa Marines to Guam in the coming years, which will also require new live-fire training ranges and military housing.

Both the Navy and Marine Corps proposals are undergoing public scrutiny on Guam and across the CNMI. Military officials are holding public hearings at schools and community centers this month (November). The services are collecting public input on training options and plan to make separate final decisions on the expansions in 2015.

While the projects are expected to produce local jobs and an economic boost, environmental concerns may be hurdles for both plans.

For the Navy, the continuation of its existing training and the addition of new weapons systems require the federal government to renew its permits to disturb, injure and kill some marine mammals such as whales and dolphins. Under federal law, all marine mammals are protected species while some are endangered and have additional legal protections.

The effect of Navy sonar on sea life has raised the ire of some environmental groups for years. In September, a federal judge in California ruled in favor of groups that sued the Navy over similar plans and permits for sonar use in the Pacific Northwest are being reconsidered, according to Reuters.

Humpback, sperm and blue whales are known to live in the Marianas training area and are “likely to be adversely affected” by training. But Van Name said the Navy does not plan to significantly increase the overall use of sonar or the number of whales and dolphins that might be killed, despite the potential uptick in operations.

Some also worry the Marine Corps use of Pagan could destroy the island and its environment.

“There is ample evidence that when Marines take an island for live-fire training, they ultimately destroy it,” said Michael Hadfield, a biology professor at the University of Hawaii at Manoa who headed the 2010 U.S. Fish and Wildlife survey of Pagan.

Hadfield said both Kaho’olawe in Hawaii and Farallon de Medinilla in the Northern Marianas were islands used as U.S. military bombing ranges and are now uninhabitable.

Bombing on Pagan could disrupt thousands of native and endangered birds as well as bats, snails and more than 200 unique insect species. There are also remnants of habitation that date back over 2,000 years and should be preserved, Hadfield said.

“The best-case scenario for Pagan island is to leave it alone,” he said.

Fisher said any effects on land and surrounding waters will be considered during the Marines’ ongoing environmental assessment, which includes work with local and federal agencies such as the Fish and Wildlife Service to minimize or compensate for damage to the environment, he said.

“It is important to recognize that there are more endangered species within military installations because of the U.S. military’s commitment to protecting habitats and ensuring natural resources are protected,” Fisher said.

In addition, the Navy and Marines generally compensate for damage to one island by rehabilitating and protecting other natural habitats in the area. The Navy funded the rehabilitation of Sarigan, an uninhabited island in the Northern Marianas, as mitigation for their use of the nearby island of Farallon de Medinilla as a practice range. Sarigan is now considered a recovered ecosystem and home to a large population of endangered Micronesian megapode birds.

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