The fisher provided a GPS position and estimated that there was an area of approximately 4000sq m with snapper floating in it.
On arrival at the scene, Opotiki fishery officers collected samples of snapper still floating. All were found to be well over the minimum commercial size limit of 25cm.
Tom Teneti, Ministry of Fisheries field operations manager for Poverty Bay, said dumping of legal size quota species was prohibited under the Fisheries Act 1996 because all legal size quota species must be landed and counted against the fisher's annual catch entitlement (ACE).
Fishery officers found blue paint embedded under the scales of two of the snapper, Mr Teneti said.
"The paint was scientifically tested by the University of Otago Chemistry Isotrace unit. This contributed to identification of the source of the dumped snapper - the Garraway."
Electronic evidence obtained from the vessel was also used in the investigation to identify it as being in the vicinity at the time the fish were dumped.
"A process of elimination was applied to make sure no other vessel could have been involved in the vicinity of the detected dumping," Mr Teneti said.
The paint samples provided a "unique signature" and ultimately a strong case against the fisher charged.
Paint samples were analysed by the Isotrace Unit of University of Otago Chemistry Isotrace unit using Laser-Ablative Inductively Coupled Plasma Spectroscopy (LA-ICPMS).
This determines the proportions of various elements and isotopes in a sample, to very fine concentrations.
Investigators were able to use this information, as well as statistical methods, to analyse the data.
It suggested that both the paint found on the snapper and paint from the Garraway were similar and distinct from other samples obtained during the investigation. Initially the case had been set down for a two-week defended hearing due to the involved nature of the case, which had 13 witnesses for the Crown. However, Harvey pleaded guilty.
If the case had proceeded to a defended hearing, witnesses called would have included three scientists, a specialist statistician and computer forensic specialists.
In his sentencing report, Judge Phil Moran said the aggravating features of Harvey's offence included the large number of snapper dumped, the waste of over-fishing, with 40 per cent of the catch returned to the sea, a potential saving of $13,000 by not landing and returning the catch, and the undermining of the quota management system.
"This was a cynical dumping of a large quantity of a high value species for commercial gain, an offence that struck at the heart of the quota management regime."
Harvey was not charged as principal offender, but was charged with aiding his employer West Coast Fishing Ltd to return snapper of legal size to the sea.
The Ministry of Fisheries withdrew the charge against West Coast Fishing Ltd.
But Judge Moran said Harvey's culpability "has to be high".
"... he is the person who actually dumped the fish."
Harvey has no previous convictions for offences against the Fisheries Act.
But Judge Moran said it was a "significant aggravating fact" that in 2004 he was the skipper of a vessel operated by Harvey Fishing Ltd which was convicted of an offence of abandoning snapper at sea.
The charge carried a maximum fine of $250,000 and/or a community based sentence. Harvey, who continues to be employed by West Coast Fishing Ltd, did not wish to comment.
- Bay of Plenty Times
