Pickleweed and mangroves are aggressive non-native plants that are spreading rapidly through coastal wetlands, where they displace, and sometimes eliminate, native vegetation and wildlife. One species of waterbird, the Hawaiian stilt, has been declining in numbers as these non-native plants invade the open mud. ats it needs for foraging and nesting. The bird is federally listed as endangered.

Though the number of Hawaiian stilts counted in Marine Corps Base Hawaii’s wetlands dropped to just 60 in the early 1980s, the base still hosted one of the State’s largest concentrations of the birds. However, pickleweed and mangroves were creeping into traditional feeding and nesting areas, threatening to wipe out the remaining birds, ultimately contributing to their possible extinction. 

Sierra Club, Hawaii Chapter; Hawaii Department of Land and Natural Resources; Marine Corps Base Hawaii, 3rd Marine Regiments Combat Assault Company, USDI Fish and Wildlife Service’s Paci. c Islands Of. ce, schools, civic groups, and citizens.

In the early 1980s, Base natural resources staff and Marines began teaming with civilian volunteers such as the Sierra Club and other groups to host "ecology camps" to remove mangrove and pickleweed by hand. At the same time, Marines began what is now an annual "Mud Ops" tradition, where weed removal joins Marine training maneuvers. Using 26-ton amphibious assault vehicles, Marines plow through pickleweed in wetland mud. ats, improving stilt habitat before the onset of nesting season while gaining valuable training experience.

While using amphibious assault vehicles might seem heavy-handed, it controls the noxious weeds, allows stilts and native plants to re-establish themselves, and provides the Marines with essential training. Machines developed to operate in wartime are waging an ecological battle. In addition, the event accomplishes in two days what it would take contractors weeks to do. And it’s successful: the number of stilt counted on the Base over twenty years has risen from 60 to 160. The Base is beginning to collaborate with State agencies and other organizations to remove mangroves in adjacent Kaneohe Bay, Oahu to prevent their spread. "Mud Ops" is featured annually in the media and, in 2004, a nationally distributed poster featuring the event was produced as part of the Marines’ Saving a Few Good Species awareness campaign. After 23 years, the Marine Corps Base Hawaii has removed all mangroves from its wetlands, kept pickleweed in check, and has been recognized in the State’s Aquatic Invasive Species Management Plan as a proactive conservation leader.