There are a number of important factors that need to be taken into consideration in fish farming, such as the depth and flow of water, temperature and shelter. Fish need a plentiful supply of well-oxygenated and unpolluted water. A good depth of water allows adequate space between the pen and seabed, while a good water flow ensures a constant supply of dissolved oxygen and maintains the water quality.
Temperature is an important factor in determining fish health and growth. Salmon thrive in cooler waters and best growth is achieved at a temperature of 12-17oC.
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, as does the presence of predators - seals, sharks and dolphins.
King salmon is the main finfish farmed in New Zealand. The sea pens used by New Zealand King Salmon sea farms are designed specifically for New Zealand conditions and are up to 40m deep. The net is suspended from a flotation collar and in the pen the young fish are fed until ready for harvest. Salmon are visual feeders, so only feed during the day. The depth of the pens offer improved growing conditions, allowing the fish to move below the surface water and away from surface related stress.
New Zealand King Salmon is dedicated to producing a top quality product. This is achieved through managing several key factors: choosing a pristine and unpolluted rearing environment; the absence of the serious diseases that cause problems in the northern hemisphere; safe feed ingredients; and careful harvesting methods using Aqui-S - a natural anesthetic developed in New Zealand that is safe for use in food and which has been favourably reported on by the British Humane Slaughter Association.
New Zealand King Salmon’s innovative farming, processing and distribution operations are seamlessly integrated into a single system. This allows monitoring and control at all stages, with rigorous quality standards applied throughout all facets of the operation. All fish are documented and closely monitored throughout their lives, so that every product can be traced right back to selected broodstock.
All feed ingredients are also traceable. Feed is imported from overseas, from Australia and Chile, from reputable feed suppliers who source safe feed ingredients that will meet the nutritional needs of the fish. Salmon thrive on food high in protein and fat and typical proportions of the feed are protein 40%, oil 26%, carbohydrate 18%, ash 8% and moisture 8%, with vitamins and minerals added to provide a balanced nutritious diet. Feed components comply with all legislation.
New Zealand King Salmon provides exceptional customer service. King salmon is valued as a premium eating salmon and only small tonnages of cultured salmon are available on the world market. With 50% of production exported, distribution demands flawless logistics and a close working relationship with customers. Each product is specified for an individual customer or market and must meet international HACCP quality standards for which New Zealand King Salmon is independently accredited. Salmon are harvested 52 weeks of the year, processed quickly and transported efficiently, guaranteeing that a consistent, reliable supply of fresh product is arriving in prime condition in any world marketplace within 60 hours of harvest. Government regulatory authorities inspect and monitor our processes for compliance with health and access requirements of consuming countries.
As a new industry establishing itself over the last 30 years during a time of increasing awareness of the environment, aquaculture has been the subject of close scrutiny from the start and regulation of its effects is now well advanced in New Zealand. Independent monitoring of these effects is a requirement of the regulations and this is provided by the Cawthron Institute, a private scientific service provider in Nelson. The Cawthron Institute performs detailed annual monitoring surveys and reports on its findings. The data from these surveys allows the implementation of environmental standards based on sound scientific understanding. Using this knowledge, the company’s Environmental Management System is well above legal requirements.
Assessments of farm performance by the Marlborough District Council have also been carried out utilising Cawthron's independent monitoring and have concluded that effects on the environment are minor, localised, not progressive and meet the sustainability requirements of the Resource Management Act and the local community.
A pristine marine environment with adequate water flows and water depth in a sheltered location is essential for commercially viable and sustainable fish farming, and the Marlborough Sounds provide this environment for New Zealand King Salmon’s sea farms.
Salmon have a particularly high requirement for water quality therefore it is in the company’s interests to avoid effects that will degrade the growing environment. Successful sea pen farming relies on dispersion and dilution of wastes in deep, well flushed waters. Sustainability is achieved through avoiding permanent and irreversible changes to the natural marine environment. Therefore, all structures are easily moveable, a good understanding of environmental processes has been achieved, the ability of the environment to fully recover within several years has been demonstrated, and effective methods of monitoring and managing effects around the farms have been put in place.
The company culture aims for a high level of environmental performance and is proud of its achievements. To be successful, the business not only requires a healthy fish-rearing environment but it also makes a special effort to minimise the environmental effects of all the other aspects of the company’s operations.
New Zealand King Salmon sea farm sites were chosen carefully. They need deep enough water for pens to be clear of the seabed and allow tidal dispersion of wastes; sufficient water flow to maintain high water quality within the pens; shelter from wind and waves; high quality water with minimal pollution, low variation in temperature, salinity, low risk of harmful algal blooms, and adequate separation from other sea farms for disease management.
Because of its isolation, New Zealand is uniquely free of all of the serious pathogenic diseases that can affect salmon, therefore New Zealand King Salmon can farm in a natural and wholesome way. Pathogens are regularly screened for by the Ministry of Agriculture and Forestry and New Zealand King Salmon's own fish health monitoring programme – none have been detected.
The key environmental issues for sea farmers are; the effects of organic particles of feed and fish faeces settling on the seabed below the pens, depletion of dissolved oxygen in the water, and nutrient enrichment. New Zealand King Salmon fish do not suffer from sea lice as King salmon are naturally resistant and sea lice in the Southern Hemisphere are smaller than those found in the far north. Therefore New Zealand King Salmon do not carry out any sea lice treatments.