The Ministry of Fisheries is vowing to keep up the pressure on paua poachers after three people were sentenced in Northland's courts for plundering the shellfish.

The Ministry's Northland regional manager, Darren Edwards, said the recent convictions showed the Ministry was targeting those who showed no regard for the future of the country's fisheries.

On November 11, Greg James Frearson was sentenced in the Dargaville District Court to 150 hours community service after pleading guilty to one charge of taking excess paua and one charge of taking undersize paua. Frearson was found at Kawerua, on Dargaville's west coast, on April 27 with 121 paua, all of which were undersize.

"The daily limit for paua is 10 per diver, with a minimum size limit of 125mm along the longest part of the shell," Mr Edwards said.

Shane Wikaira was remanded on bail to February 8 for a pre-sentence report after pleading guilty to four charges in relation to possessing excess and undersize paua, providing false details to a fishery officer, and fishing while prohibited.

Wikaira was caught by officers at Kawerua on July 19 with 66 paua, 64 of which were undersize.

Tane Kikara was sentenced to 80 hours community service, after pleading guilty to one charge of possessing excess paua and possessing undersize paua.

He was caught at Kawerua on July 19 with 67 paua, 64 of which were undersize.

Said Mr Edwards: "Fisheries regulations are there to ensure we have a sustainable fishery both now and into the future.

"This sort of blatant plunder could have long-reaching effects on local pauastocks."

He said fishery officers would continue to actively seek out offenders.

But they could not be everywhere and he urged people to play their part in helping catch the plunderers.

"We need to have four million guardians of our coastline and fisheries this summer," Mr Edwards said.

People should report any suspicious fishing activity to the Ministry of Fisheries by calling 0800 4 POACHER (0800 476224).