SYDNEY, Australia — A record number of Indonesian fishing boats were caught poaching in Australian waters last year, but the government admitted Monday most crews were simply stripped of their catch and fishing gear and sent home.

The number of seizures of illegal fishing boats, which are endangering the survival of Australia's northern fisheries, have increased in recent years to a record 131 last year, an increase of about 10 boats from the previous year, said Fisheries Minister Ian Macdonald.

Some Indonesian crews were brought to the northern city of Darwin and prosecuted while their boats were impounded, he said.

However, Macdonald said a larger number of boats were intercepted by authorities who confiscated their catch and fishing equipment before allowing them to sail home.

Australian newspapers reported Monday that Australian Customs Service patrol boat crews had been directed to confiscate the catches and fishing gear — so-called administrative seizures — rather than arrest the poachers, because the rising numbers of illegal fishers were overwhelming staff.

Macdonald would not confirm the reported customs order but defended customs and navy patrol boat crews' use of "administrative seizures" instead of arrests.

"We'll continue to use a mix of approaches, depending on the circumstances," said Macdonald.

Macdonald said the current force of eight customs and 16 navy patrol boats, plus surveillance aircraft from Coastwatch — which scour northern waters in search of poachers and drug and people smugglers — were not overwhelmed.

"We have the resources. I'm confident that between customs, navy, and Coastwatch, our operations in the north will be effective ... and will deter (poachers)," Macdonald said. "As they see more and more arrested, boats and fishing gear taken, we think that we eventually will (deter them)."

Indonesian poachers are often caught with protected dolphins and turtles among their catches and have been blamed for a number of Australian fisheries being threatened by overfishing.