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Our fisheries and the impact of fishing on marine ecosystems

Throughout New Zealand’s human history, the bounty of the sea has provided people with food and goods for trade. When Polynesian settlers first arrived 700–800 years ago, New Zealand’s coasts and oceans provided an abundance of food and resources. Over time, Māori developed practices to conserve these resources and fishing became a source of economic and cultural wealth for iwi and hapū.

The marine environment continues to be important in the Māori economy. Kaimoana (fish, crustaceans, and molluscs) was the top export commodity of Māori authorities in 2015, accounting for $304 million or 63 percent of all merchandise exports. It was an important commodity for Māori small and medium-sized enterprises (Statistics NZ, 2016b). A number of coastal areas are set up as mātaitai (reserves) and taiāpure (local fisheries) for customary Māori fishing.

Fishing and aquaculture industries contributed $896 million (0.4 percent) to New Zealand’s gross domestic product in 2013, providing over 47,000 jobs (Statistics NZ, 2016a). The marine environment also supports an informal economy for perhaps as many as one-third of New Zealand adults who recreationally fish, dive, or harvest shellfish to feed family and friends (Ministry of Fisheries, 2008).

This report has already discussed some threats to fisheries and aquaculture – such as ocean acidification and warming, sedimentation, and marine pests. However, fishing has its own impact on fish species and marine ecosystems. This chapter is primarily about the impact of fishing on the environment.

A cross-cutting issue

Fishing is both a highly valued human activity and a pressure on marine species and ecosystems.

Commercial fishing

Of New Zealand’s commercial fish stocks, 17 percent were assessed as overfished in 2015, comparing favourably to about 29 percent of overfished fish stocks worldwide.

Seabed trawling and dredging

Seabed trawling and dredging cause widespread harm to seabed habitats. These methods mostly occur in coastal waters – the part of our marine environment under the most pressure from human activities. Commercial trawl and dredge tows have decreased since the late 1990s.

Bycatch

Most fishing methods can result in the accidental death of non-target species (bycatch). Bycatch has been decreasing over the past 15–20 years but is still an important cause of death for rare species of seabirds and marine mammals.

Ecological sustainability

To draw firm conclusions about the ecological sustainability of fishing our reporting programme would need data on the impact of commercial, recreational, and customary fishing on a wider range of non-target species and marine ecosystems.