[3][4] In 2006, the aquaculture industry in New Zealand developed a strategy aimed at achieving a sustainable annual billion NZ dollar business by 2025.

It takes place in New Zealand in coastal marine areas (mariculture) and in inland tanks or enclosures.

[citation needed] There are three main species in the New Zealand aquaculture industry: the green-lipped mussel, the Pacific oyster and king salmon.

The Hauraki Gulf and the Marlborough Sounds provided sheltered environments, with clean water rich in plankton.

Biodegradable stockings were packed with spat and tied to parallel rows of looped ropes, supported by buoys.

Young mussels grow through the stockings, anchoring themselves to the ropes with their strong byssal threads (beards).

[10] The farms are usually located in sheltered or semi-sheltered areas where there is sufficient depth of water at low tide to keep the longline droppers off the bottom.

[8] Initially the ropes were allowed to reseed naturally, after harvest, from the spat already present in coastal waters.

In 1974 a marine scientist discovered mussel spat encrusted on drift kelp on Ninety Mile Beach.

[2] Improved techniques have led to rapid production increases, and bulk handling methods have been introduced to meet growing demand for export to more than 60 countries.

During the 1960s, commercial farmers grew rock oysters on sticks coated with cement, and laid in racks in the lower intertidal regions of harbours and inlets around the northern North Island.

Instead of using the North Island method of cultivating oysters on racks, Marlborough farmers used hanging longlines, a system developed in Australia.

The venture was originally aimed at ocean ranching, where juvenile salmon would be released into the sea with the expectation that some would return as adults.

Smolt (young fish) from freshwater hatcheries are transferred to cages containing several thousand salmon, and remain there for the rest of their life.

The Tekapo site, fed by fast cold waters from the Southern Alps, is the highest salmon farm in the world, 677 metres above sea level.

[8] Lack of disease in wild populations and low stocking densities used in the cages means that New Zealand salmon farmers do not use antibiotics and chemicals that are often needed elsewhere.

Enhancement is the name given to techniques designed to boost the natural recruitment or survival of young animals or seaweed in the wild.

The scallop larvae settle out of the plankton onto the fine feathery surface of the plastic mesh bags.

The larvae are allowed to grow to a suitable size and are then released onto known natural scallop beds at densities of about six per square metre of sea floor.

[19] Aquaculture consents developed haphazardly, with regional councils unsure about how marine farms might impact coastal environments.

By 2001, some councils were inundated with marine farm applications, and were operating with inadequate guidelines for sustainably managing the coast.

[20] As the Ministry for the Environment put it: "Attempts to minimise local or cumulative environmental effects resulted in bottlenecks, delays and high costs in processing applications for new marine farms, local moratoria, submitter fatigue and poor environmental outcomes.

They now offer nationally recognised training programmes based on the needs of companies involved in aquaculture.

These funds are mostly delivered through a competitive bidding process, organised and controlled by the Foundation for Research, Science and Technology.

[2] In pre-European times, the indigenous Māori of New Zealand undertook rudimentary aquaculture activities, such as placing suitable rocks into the intertidal settlement zones of oyster larvae.

However, inappropriate aquaculture locations and unsustainable practices have the potential to compromise values and resources important to coastal whānau, hapū and iwi.

[27] NIWA operates a Māori research and development unit, Te Kūwaha o Taihoro Nukurangi.

The unit has a team of Māori scientists who undertake research and provide consultancy services, based particularly around iwi with environmental and commercial issues.

[22] The New Zealand industry currently relies on low-value filter-feeding shellfish (mussels and oysters) which are fast growing and relatively easy to culture.

These species need special food supplies and are more expensive to farm, but they command higher prices.