About 250 kilograms of sea cucumber and 15 shark fins have allegedly been seized from an Indonesian fishing vessel intercepted in Australian waters.

The boat and its eight crew members have since been towed to Darwin.

The Australian Fisheries Management Authority’s (AFMA) Peter Venslovas said the vessel was spotted by an aerial surveillance plane last week and then intercepted by HMAS Armidale off the north-west coast of Australia.

“They’ve been brought to [Darwin] port and it’s an activity we want to investigate and deal with strongly, because we take illegal fishing very seriously,” he said.

Mr Venslovas said the boat would be destroyed and the crew will soon face court.

Sea cucumbers, otherwise known as trepang, are regarded as a delicacy in many Asian nations.

Incidents of illegal fishing in Australian waters peaked in the mid-2000s, according to AFMA.

“It peaked in the financial year of 2005-06 with 648 interceptions,” Mr Venslovas said.

“Then from about 2008, and for about a decade, that number fell to an average of 15 to 25 interceptions a year.”

But he said numbers increased during the COVID pandemic and there had been 85 interceptions so far this financial year.

“We have a good relationship with our counterparts in Indonesia and we visit those particular ports where these operators come from to explain where the boundaries are and what the ramifications are if they get caught,” he said.

“They run the risk of losing their vessel and their livelihood, and they shouldn’t be undertaking those forays in the first place.”

In 2021, Operation Jawline saw Border Force patrol boats intercept 19 Indonesian fishing vessels carrying approximately 860 kilograms of trepang in a two-week period.