King Salmon boss defends feeding regime

New Zealand King Salmon chief executive Grant Rosewarne
New Zealand King Salmon chief executive Grant Rosewarne

Monitoring results for New Zealand King Salmon farms in the Marlborough Sounds are open to interpretation, says company chief executive Grant Rosewarne.

Mr Rosewarne was responding to the Marlborough District Council decision to get advice on whether it needed to serve King Salmon with an abatement notice after 2012 monitoring showed some farms did not meet standards.

When King Salmon established its Clay Point and Te Pangu farms in Tory Channel, little was known about growing salmon in these high- flow conditions, Mr Rosewarne said. It was valid to change resource consent conditions as knowledge increased, he said.

The seabed was more affected than conditions allowed at a monitoring point between the Te Pangu farm in Tory Channel, Mr Rosewarne said.

However, it could be argued that this was irrelevant because thresholds were met beneath the farm and at the outer limits of monitoring.

Cawthron Institute reported that King Salmon fed out 300 tonnes more feed than allowed at its Clay Point Farm, on the opposite side of Tory Channel.

Mr Rosewarne said the over-feeding was due to a spreadsheet error not discovered until the end of the year. However, this was balanced out by fish at Te Pangu being given 300 tonnes less feed than allowed and pellets containing less nitrogen than in the past, he said.

King Salmon would apply to the council to increase feed at Clay Point from 4000 a year to 4500 tonnes, Mr Rosewarne said.

Cawthron monitoring also picked up high copper residues under some farms.

Mr Rosewarne said the residue problem had prompted King Salmon to stop treating nets with anti-fouling chemicals. The company was instead using net cleaning equipment it developed, requiring two to four extra staff.

He welcomed a call from Cawthron for more international research on harmful algal blooms and fish farms because this would confirm there was no link, Mr Rosewarne said. Cawthron put the request on the agenda of algal bloom experts working under the Unesco-supported Geohab programme who met in Paris last month.

A toxic algal bloom has shut down mussel farms in Queen Charlotte Sound and Tory Channel this autumn.

"The amount of nutrients coming in from salmon farms is not enough to impact the natural cycle," Mr Rosewarne said.

Mussel farmers claimed a lack of nutrients in the Marlborough Sounds this season meant their crop failed to reach full size, he said. Nutrients from salmon farms might help.

King Salmon was constantly restructuring to save jobs including changes to Marlborough management positions, Mr Rosewarne said. Production peaked in 2010-11 and would continue to fall as the company changed towards single age-group sites as a biosecurity measure, he said.

"Instead of overlapping the end of last year's brood with new season brood, we are going to keep them separated. If salmon disease does come to New Zealand, we should be well prepared," Mr Rosewarne said.

Four new farms approved at an Environmental Protection Authority hearing in Blenheim last year were to have offset these reductions. However, Sustain Our Sounds and the Environmental Defence Society had appealed, which delayed the expansion, Mr Rosewarne said

He dismissed as "ridiculous" King Salmon being placed second equal in a Campaign Against Foreign Control of Aotearoa Roger Award this month. Overseas investment was a better way of funding New Zealand industry than borrowing which meant paying a portion of profits in interest, Mr Rosewarne said.

The Marlborough Express