Download FAR 2026/14 Environmental variability and change in the LIN 3&4 stock region

Ling is a commercially important fish species. An important ling fishery takes place on Chatham Rise.
Fish and fisheries are affected by environmental conditions. Environmental conditions in Aotearoa New Zealand are affected by climate variability and change.
We used information from drifting buoys, satellites and computer modelling to describe the oceanographic conditions experienced by ling on Chatham Rise over the last 40 years.
Chatham Rise is an underwater feature that extends eastwards for about 800 km off the east coast of the South Island, with the Chatham Islands at the far end. The ocean is particularly productive here because it is where ocean currents meet, leading to good conditions for phytoplankton; the tiny plants living in the upper ocean. This in turn supports a rich food web, including ling and other deepwater fish.
Environmental observations show that the oceans around New Zealand are getting warmer, and the pace of warming has accelerated over the last 20 years. Chatham Rise is warming particularly quickly, and the warming extends from the sea-surface to the seabed though warming at the seabed is slower than at the surface.
Part of the mixing zone (front) that forms on Chatham Rise has also moved.
Warming has been accompanied by variations in ocean productivity in the Chatham Rise region, but with no substantial long-term trend.
The changes in environmental conditions on the Chatham Rise do not explain the change in ling catch rates or recruitment since 1990.
In parallel with the environmental change, from about 2018 the ling bottom longline fishery partially moved and contracted into areas that have slightly cooler surface temperatures but warmer bottom temperatures.