A number of important factors need to be taken into consideration when choosing salmon farm sites to ensure commercially viable and sustainable farming.
New Zealand King Salmon’s sea farm sites were chosen very carefully. The sites need deep enough water; sufficient water flow; shelter from wind and waves; high quality, cool waters with low variation in temperature and salinity, and adequate separation from other sea farms.
Certain parts of the Marlborough Sounds provide this ideal environment, essential for our salmon to thrive and grow.
The good depth of water in the Marlborough Sounds allows adequate space between the pen and seabed, allowing tidal dispersion of wastes.
Good water flow ensures a constant supply of dissolved oxygen and maintains the water quality. Our sea farms are strategically positioned in the remote areas of Queen Charlotte and Pelorus Sounds where tides are continually flushing water in from the Cook Strait.
Salmon need a plentiful supply of well-oxygenated and unpolluted water. The purity of the water is vital to fish health.
Shelter is important. Wind and waves can affect feeding even with the protection of sea pen structures. Net movement during rough weather may also cause stress, so the bays in the Sounds where the farms are situated provide appropriate shelter.
Temperature is an important factor in fish health and growth. Salmon thrive in cooler waters and best growth is achieved at a steady temperature range of 12-17C. The waters of the Marlborough Sounds provide this cooler temperature range.
The sites need to have adequate separation from other sea farms for disease management. Fortunately, New Zealand is isolated and known diseases that can affect salmon elsewhere have not occurred here. Nevertheless, we still practice appropriate biosecurity measures to protect each farm and therefore sea farms are located a stipulated minimum distance apart.
Farms sites are chosen to have minimal impact to residential neighbours, tourism operators, recreational Sounds users, marine mammals, and other Sounds wildlife, and farms must comply with associated legislations.
In 2011 New Zealand King Salmon applied for a change to the Marlborough Sounds Resource Management Plan, and for resource consents to farm nine new sites. Prior to this, no new space had been allocated in the Marlborough Sounds for salmon for many years.
In April 2014, as a result of the application and after various hearings, the Supreme Court of New Zealand granted New Zealand King Salmon three new farm sites; Waitata, Kopāua and Ngamahau.
Despite this new space, salmon farming in Marlborough still has a tiny foot print. Our farms represent about 0.1 per cent of the total surface area of the Marlborough Sounds – the equivalent of 10 hectares out of 10,000.
Certain parts of the Marlborough Sounds provide an ideal environment, essential for our salmon to thrive and grow.