New Zealand's oceanic and coastal temperatures have hit their highest levels since records began in 1982.
New data released by Stats NZ showed oceanic sea-surface temperatures increased on average between 0.16C-0.26C a decade.
"Measuring sea-surface temperature tells us how rapidly the ocean's uppermost productive layers are warming," Stats NZ environment and agricultural statistics senior manager Stuart Jones said.
Coastal regions warmed on average by between 0.19C to 0.34C per decade (equivalent to 0.74C to 1.35C during the recorded period), with the east coast of the South Island having the highest average rate.
Each oceanic and coastal region experienced their hottest years on record in 2022 or 2023.
Changes in sea-surface temperatures could impact marine processes, environments, species, and nature's contribution to people, Stats NZ said.
This could include some species, including some sharks, dolphins, and whales, changing location to maintain their temperature or the possibility they would not survive if they could not move.
It could also cause changes to growth and reproduction of fishes such as snapper, as well as an increase in the occurrence of invasive species.
Marine heatwaves, prolonged periods of unusual seawater warmth, also reached new levels. The west of the North Island experienced a marine heatwave for 89% of 2022, and the Tasman Sea spent 61% of the year in a heatwave.
The data was sourced from the National Institute of Water and Atmospheric Research (NIWA), National Oceanic and Atmospheric Administration (NOAA), National Aeronautics and Space Administration (NASA).
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