A surge of online seafood for sale has seen poachers in Northland taking orders before they collect seafood and illegally sell their catch through social media.
The summer months have seen an increasing number of people offering a smorgasbord of seafood for sale on Facebook pages and fisheries officials in Northland are calling on members of the public to help stem the tide.
Paua, pipi, mullet, snapper, kina and crayfish have all been up for grabs - for a price - on various Facebook sites in the past few months.
One recent post stated: "$80 sack of kinas ... Pre-Order now divers going out in morning ... pm if interested GOING FAST."
Another offered oysters "picked fresh from the Bay of Islands" and available later in the week, while 25kg bins of fresh mullet from the Kaipara were selling for $100 but "be in quick before we sell out".
The sale of recreationally taken seafood is illegal and an offence under the Fisheries Act and those buying the seafood are equally liable as those selling and face a maximum fine of up to $250,000 and confiscation of any gear used in the crime.
The Ministry for Primary Industries (MPI) says the black market in seafood has always been a problem but the explosion of social media has made it an even bigger problem.
Northland fisheries officer Kyall Boonensaid there were plenty of pages and closed groups in Northland where seafood was being offered for sale and there was an obvious demand.
"Posting on Facebook is a fast way to get it out there to a big audience and it's easy to withdraw a post pretty quickly too," Mr Boonen said.
"They are undercutting those who are doing it legitimately. They want quick, fast money and there are people in the community willing to pay for it on a first-in, first-served basis. The faster they can get rid of it and get cash the better."
It was an offence to offer seafood even if there was no sale conducted and swapping seafood for a koha or another item was also illegal.
"You can't trade seafood to obtain a benefit," Mr Boonen said.
To crack down on the trade, members of the public seeing posts online could take a screen shot of the post and contact MPI or private message the ministry through its Facebook page, MPI Fisheries - Northland.
"We are getting plenty of information from the public but the more eyes the better because we can't be everywhere."
He said MPI would investigate no matter how big or small the amount of seafood on offer.
Public help led to the successful prosecution of two women last year after they raffled kina roe, crayfish and oysters and sold crayfish via Facebook.
Santi Samuels-Taylor, 40, from Kamo, and 23-year-old Peti Elizabeth Mark, from Raumanga, were convicted and fined $1000 each under the Fisheries Act.
There are a number of Northland cases going through the court at the moment involving the illegal sale of seafood online.
Mr Boonen warned people who bought black market seafood could also expose themselves to potential health risks, as there was no assurance the product had been processed or stored hygienically.
To legally sell fish the vendor needs to be a registered licensed fish receiver, dealer in fish or a commercial fisherman and must also have all the relevant documentation.
Anyone wishing to report illegal seafood sales on social media are asked by MPI to take a screenshot and contact its confidential hotline on 0800 4 POACHER (0800 4 762 243).