A stateless fishing vessel suspected of illegally drift-netting in high seas is being escorted into the Port of Dutch Harbor this weekend. The Coast Guard intercepted the Bangun Perkasa in mid-September, 2,600 miles southwest of Kodiak.

The crew initially tried to cut their nets and flee when spotted by a patrolling Coast Guard helicopter. Once boarded, they falsely claimed the vessel was registered in Indonesia. The boarding team discovered 10 miles of drift net, 30 tons of squid and 30 shark carcasses onboard the Perkasa. High seas drift-netting is banned by the United Nations.

Coast Guard Petty Officer Sara Francis says it’s harmful for ocean ecosystems.

“[Drift-netting is] indiscriminate. It catches everything in its path. It can seriously harm fish stocks,” says Francis. “The US Coast Guard actively participates in international cooperative efforts against high seas driftnet fishing, which is encouraged by the United Nations moratorium.”

Usually illegal fishing vessels are sent back to their home countries, but stateless vessels have to be seized and escorted to a U.S. port. In the Perkasa’s case, this poses a problem because in addition to its illegal catch, the boat is carrying rats. Because of the danger rats pose to the Aleutian ecosystem, the Coast Guard is holding the boat outside state waters until all of the rodents are exterminated.

Once in port, the National Oceanic and Atmospheric Administration’s Office of Law Enforcement will assess the boat’s catch to determine criminal and civil liability. Vessels fishing illegally face criminal penalties of up to $100,000 and civil penalties of up to $25,000.

All 22 crewmembers will remain onboard the Perkasa until Customs and Border Protection can determine their countries of origin. They speak five different languages, including Chinese, Mandarin, Vietnamese, Taiwanese, and Indonesian, but it is unclear whether they have any official documentation. The crew will also be questioned about whether they were working with other vessels and who is financing and profiting from the illegal fishing.

It has been at least five years since the Coast Guard intercepted a pirate vessel of this kind.