TWO illegal fishing vessels and their crew had been apprehended off the Northern Territory, Fisheries Minister Ian Macdonald said today.

The apprehensions yesterday – the first for the year – were a warning to illegal fishers that Australia remained committed to border protection, Senator Macdonald said.

The first vessel, with eight crew, was apprehended by Customs officers north-west of Weipa, about 80 nautical miles inside the Australian Fishing Zone (AFZ), yesterday.

About 10kg of shark fin was allegedly found on board, Senator Macdonald said.

Authorities were still waiting to interview the crew, who were being towed to Thursday Island.

A second vessel was apprehended shortly after, north-west of Cape Londonderry, about 50 nautical miles inside the AFZ.

The seven crew members would be interviewed once they arrived at Darwin.

Senator Macdonald said authorities would continue to detect and arrest anyone taking part in illegal fishing.

"While many other Australians are still enjoying the New Year break, the efforts of these dedicated officers should be a warning to illegal fishers that Australia keeps watch on its waters 365 days of the year," Senator Macdonald said.

"Those illegal fishers who feel they can plunder our well managed fish stocks and get away with it are sadly mistaken."

Last year, authorities apprehended a record 138 vessels, Senator Macdonald said.