In the video, Mr Packer is on a boat moving through the area pointing out the dead fish which are floating at the surface "by the dozen, everywhere you look".
He lays the blame firmly on a commercial trawler, alleging the vessel didn't "have the quota to land these".
"The quota system is designed to do this New Zealand, this is exactly what it is designed to do," he said in the video. "It's not designed to protect the fishery, it's designed to make money out of it. And this is what's happening, in the pursuit of big, big dollars."
In the messages posted under the video on his Facebook page, Mr Packer indicated he had seen a commercial vessel dump the haul, and had reported it to MPI.
Asked to 'name and shame' the culprits, Mr Packer replied: "MPI are in receipt of all the relevant information and [I] would rather not do anything to stop that process."
In a statement this evening, MPI said its compliance department had identified the vessel involved and it had "reported accidentally losing a quantity of gurnard when retrieving its gear".
"The vessel reported the accidental loss in accordance with its requirements under the Fisheries Act," a ministry spokesman said.
"It is timely to remind the public that it is critical that they report any such incidents to MPI directly and as quickly as possible so we can do our job.
"MPI takes a serious view of any illegal activity in our fisheries and dedicate significant resources to ensuring our fish stocks are harvested sustainably and within the rules."
This morning, Scott Macindoe from LegaSea said the dump was "business as usual for the bulk harvesters".
"New Zealand is becoming a laughing stock. We keep preaching this world-leading quota management system, but we're not doing anything really tangible to address the real issue -- this ridiculous wastage," he told TV One's Breakfast programme.
