Control and Containment Efforts on the Commonwealth of the Northern Marianas Islands (CNMI), Hawaii, and Other Island Governments
Excerpted from "Integrated Pest Management Approaches to Preventing the Dispersal of the Brown Treesnake and Controlling Snakes in Other Situations" 1999.
Commonwealth of the Northern Marianas
The volume and frequency of commercial and military traffic to the CNMI, together with the ecological similarity of its islands to Guam, places these islands at very high-risk for brown tree snake introductions. The degree of emphasis placed on snake control in the CNMI has increased significantly in recent years, but more efforts are needed. Specific areas for concentration in the future include: expanding the detector dog program to Tinain and Rota; creating an emergency trapping plan which will include proper response once a sighting is made, including immediate visual searches, employment of traps, and erection of a short-term barrier in the area of the sighting; and adding barriers in high-risk ship and air traffic areas for incoming products from Guam. A recent directive from the CNMI Governor mandated that all government agencies familiarize themselves with the brown tree snake problem and cooperate with researchers and their proposed control strategies.
On Tinian, high-risk materials associated with construction of a Voice of America Relay Station are placed, upon arrival, within a concrete barrier (enclosure) constructed at the seaport. Ideally, all shipments from Guam are held in the area for 72 hours unless an inspection is completed. Planned expansion of this barrier would allow all cargo from Guam to be placed in a protected area. In addition, expansion of Tinian's airport was begun in 1999, and, although this airport represents a relatively low-risk situation for snake introduction, the Commonwealth Ports Authority implemented a brown Treesnake prevention plan outlining strategies to be included in the new airport's design. Measures included in the plan covered incoming construction materials and cargo as well as operation into the future of the new Tinian International Airport.
On Rota, all goods arriving via ship are placed within a barrier at the commercial seaport when possible. Recently, high volumes of incoming cargo exceeded the space available inside the barrier, leading to unloading outside the bounds of the barrier. If these volumes continue to arrive, an expansion will be incorporated in port construction to avoid encountering this problem in the future.
The Coordinating Group on Alien Pest Species has undertaken several actions to decrease the likelihood of brown Treesnakes entering Hawaii. This includes placing control of the snake on Guam and exclusion from Hawaii as its highest alien species concern in its "Hawaii Brown Treesnake Prevention Plan."
Hawaii Department of Agriculture detector dog and handler teams are trained to search for snakes as well as plants, fishes, etc. At present, the teams are unable to check 100% of the incoming traffic. This effort may be stepped up in the future to include all commercial and military traffic (presently, only 60% of the military aircraft arriving from Guam are inspected).
Ongoing efforts include allocating funding to fully enable the Alien Species Coordinator to oversee invasive species' threats to Hawaii and associated programs, extending barrier technology to commercial and military airports, and continuing to educate citizens and visitors on alien species issues. Special efforts are needed to discourage those who would illegally import snakes for pets or resale purposes.
Significant control efforts are needed where the threat of brown Treesnake introduction is high, but the discovery of snakes on other islands and continents documents that the threat of brown tree snake introduction is widespread. Pacific islands receiving air traffic from Guam include the Federated States of Micronesia (Pohnpei, Kosrae, Yap, and Chuuk), Palau, Okinawa, and American Samoa. The level of threat posed to these islands is dependent on a number of factors, including the frequency and type of shipments received. Wildlife Services conducts ongoing evaluations regarding the nature of commercial and military cargo that moves from Guam to different island and mainland destinations. By expanding this work to provide more detailed information on the nature of shipments to locations potentially at risk, a more refined understanding of the risks facing these locations will be possible. Likely, education will be the most effective tool for some locations, with the hope that, as incidents document increased risk, more extensive measures will be taken. In recent years, Department of the Interior biologists have traveled to Pacific Islands to conduct educational workshops with local port authorities and transportation workers. This effort should be renewed and examined as a possibility for some mainland destinations. Preventing snakes from leaving Guam remains the most cost-effective and secure method for preventing and controlling the snake in other locations.