ANCHORAGE (AP) — A 191-foot fishing boat suspected of using an illegal high seas drift net to catch a half-ton of salmon in the North Pacific was detained by the U.S. Coast Guard last week and turned over Tuesday to Chinese authorities.

The Yin Yuan was spotted by a Canadian aircraft hosting Japanese observers. It was seized by the Honolulu-based U.S. cutter Morgenthau, which was carrying two Chinese law enforcement officials.

“All these countries are affected by illegal activities,” said a Coast Guard spokesman, Petty Officer 2nd Class Grant DeVuyst.

High seas drift net fishing kills huge amounts of fish, birds and marine mammals with nets suspended for miles. The practice is universally condemned, according to the Coast Guard, and is a significant threat to ecosystems.

A Canadian CP-140 maritime patrol aircraft May 22 spotted the Yin Yuan in the North Pacific on May 22. The vessel was carrying equipment associated with large-scale illegal drift net fishing, including net, net buoys and net spreader on deck.