New Brown Treesnake Inspection Rules Now in Effect for Small Vessels Arriving from Guam

SAIPAN, CNMI – The Department of Lands and Natural Resources (DLNR) has adopted emergency regulations requiring small boats arriving from Guam to show CNMI officials that the vessel and its cargo were inspected for brown treesnakes before leaving Guam. The rules took effect on September 15, 2026, and will remain in effect for 120 days while permanent regulations are promulgated.

The brown treesnake is established on Guam but not in the CNMI, and inter-island cargo transport comprises a high-risk pathway for introductions. Since Super Typhoons Sinlaku and Bavi, shipments from Guam to the CNMI have increased to support recovery and rebuilding, raising the risk that a snake may slip through existing biosecurity measures. In July 2026, two brown treesnakes were sighted away from the ports on Rota, a clear sign that stronger protections are needed.

Why It Matters

On Guam, the brown treesnake wiped out most of the island's native forest birds and continues to threaten public health and safety. The snake also causes frequent power outages and damage to electrical infrastructure, costing Guam's economy an estimated $4.5 million each year, not counting repairs and lost revenue during outages. A study of the hypothetical establishment of the brown treesnake in Hawaii estimated damages of $593 million to $2.14 billion every year, including medical costs, power outages, reduced tourism, and the loss of 1,400 to 13,000 jobs.

Who Is Affected?

The rules apply to any boat up to 55 feet in length (inclusive) that departs Guam before entering the CNMI. This includes commercial, private, and government vessels of any type or registration.

What Is Required?

•       Inspection before departure. Both the boat and all cargo on board must be inspected on Guam and found free of brown treesnakes. Inspections must be done by United States Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) brown treesnake inspectors on Guam, or by another inspection authority approved in writing by DLNR.

•       Timing. For nighttime departures (6:00 p.m. to 6:00 a.m.), the inspection must be completed within 3 hours before departure. For daytime departures (6:00 a.m. to 6:00 p.m.), a daytime inspection is valid until 6:00 p.m. the same day. If departure is delayed beyond these windows, the boat and cargo must be inspected again.

•       Paperwork. The inspection document must identify the vessel, the inspector, the date and time of inspection, the result, and a description of the cargo, including container and seal numbers where applicable.

•       Matching cargo. The cargo on board must match what is listed on the inspection document, and any container seals must be unbroken and match the recorded numbers. The boat's captain must sign a statement confirming the cargo matches the inspection record.

•       On arrival. The captain, owner, or agent must give the inspection documents and the vessel manifest to the Division of Customs and Biosecurity at a recognized CNMI port of entry.

These requirements are in addition to the existing requirement that brown treesnake inspections are conducted by the CNMI Division of Fish and Wildlife (DFW) at CNMI ports.

Making Pre-departure Inspection Arrangements

Contact the USDA duty phone at 671-685-8992 to schedule snake inspections on Guam.

What If a Boat Is Not Compliant?

Boats or cargo arriving without valid documentation may be refused entry, held, or subjected to inspection, treatment, or containment. Violations may also result in fines, criminal penalties, or the confiscation, destruction, or return of shipments.

Report Snake Sightings

Anyone who sees a snake anywhere in the CNMI is asked to report it immediately to the DFW brown treesnake hotline at (670) 287-6253. If possible, note the location and take a photo to assist responders.

More Information

The full text of the emergency regulations is published in the Commonwealth Register, Volume 48, Number 09 (September 15, 2026).