The Alaska Supreme Court has upheld the $20,000 fine imposed on a Metlakatla commercial fisherman who took coho salmon in 2014 in a closed area, without a state fisheries permit.

In a 4-0 ruling, the justices rejected the appeal filed by the fisherman and the Metlakatla Indian Community, which had argued the state lacked jurisdiction in the waters around Alaska’s only Indian reserve.

John Scudero Jr. was cited for three commercial fishing violations and fined $20,000 after a one-day trial in 2015. The U.S. Coast Guard in 2014 reported the violations after they had boarded his vessel in wa...