Disease risk explored during salmon hearing
The risk of salmon diseases entering New Zealand will increase if New Zealand King Salmon builds new farms in the Marlborough Sounds, fish parasite expert Ben Diggles said in Blenheim yesterday.
Dr Diggles said in New Zealand, the chinook salmon farmed by King Salmon were disease-free. This could change if a new disease crossed the border or a parasite changed hosts.
King Salmon stocked its farms at about 20 kilograms of fish per cubic metre, which meant farm space was about 2 per cent fish, Dr Diggles said. This was 5kg per cubic metre below the stocking at which fish could become susceptible to disease.
Questioned by Andrew Caddie, of the Kenepuru and Central Sounds Residents Association, Dr Diggles said King Salmon used antibiotics once, 10 years ago. If bacterial disease became a problem, fish would be vaccinated one by one.
Mr Caddie said the residents' association was sent a Primary Industries Ministry interim report on salmon deaths at King Salmon's Waihinau farm, after making an Official Information Act request. It had a lot of information deleted.
The ministry submitted in support of King Salmon's expansion plans.
Mr Caddie said he understood the ministry had sent information about unusual fatty deposits around fish hearts to Norway for analysis and a final report would not be published until results were available.
Biosecurity expert Barrie Forrest said the didemnum sea-squirt, a pest in the Marlborough Sounds, would probably spread to any new farms.
The discussion took place during the Environmental Protection Authority hearing of an application by King Salmon to develop nine new salmon farms in the Sounds. The hearing is expected to continue for another eight weeks.
- The Marlborough Express