The Ministry for Primary Industries is calling on fishermen to better consider how they return carcasses to sea after rig sharks and an eagle ray were found at Onerahi foreshore this week.
A member of the public shared images on Tuesday after they discovered the shark species, also known as lemonfish or spotted dogfish, dumped near a grass boat ramp.
The Advocate visited the area on Wednesday morning and counted nine lemonfish, which had been gutted and stank.
Fisheries New Zealand regional manager for fisheries compliance Andre Espinoza said rig sharks are legal to catch in New Zealand and return to sea - but under specific conditions.
“We would encourage fishers not to return carcasses to sea very close to shore as it can leave an unpleasant odour and attract pests.”
A Department of Conservation spokeswoman said the species were not protected so were the responsibility of the Ministry of Primary Industries.
Seven species of shark and ray are protected in New Zealand including great whites, the basking shark, smalltooth sandtiger, whale shark, oceanic whitetip shark, spinetailed devil ray and giant manta ray, she said.
According to the National Institute of Water and Atmospheric Research (Niwa), rig sharks are found in coastal waters around New Zealand.
Adult females migrate into shallow coastal waters around spring and summer to give birth to live young and mate before heading to deeper waters.
The species are usually bronze or grey with a white belly and small white spots along the lateral line and their upper body.
Lemonfish feed mainly on animals that burrow on the sea floor, especially crabs.
In Aotearoa New Zealand they are a staple fish-and-chip favourite because of their firm white flesh and low oil content.