According to Stats NZ, sea surface temperatures have increased by 0.63 to 1.05 degrees Celsius across New Zealand’s ocean regions since 1982, with the Tasman Sea experiencing the highest average rate of increase.
On July 9, New Zealand’s statistics agency, Stats NZ, reported that between 2022 and 2023, the average annual temperature in the oceans and coastal areas surrounding the island nation reached its highest levels since data collection began in 1982.
Sea surface temperatures have risen by 0.63 to 1.05 degrees Celsius across New Zealand’s ocean regions since 1982. (Source: NZ Herald).
According to Stats NZ, since 1982, sea surface temperatures have increased by 0.63 to 1.05 degrees Celsius across New Zealand’s ocean regions, with the Tasman Sea exhibiting the highest average rate of increase.
Stuart Jones, the Senior Director of Environmental and Agricultural Statistics at Stats NZ, stated that coastal regions have warmed by 0.74 to 1.35 degrees Celsius, with the area near the East Coast of the South Island experiencing the highest average temperature increase.
This statistician noted that measuring sea surface temperatures reflects the warming rate of the upper layers of the ocean.
Statistical data on ocean heatwaves (when sea temperatures are abnormally warm for extended periods) have also reached new high thresholds.
According to Stuart Jones, the Tasman Sea experienced ocean heatwaves for 61% of the year in 2022, the highest among ocean regions.
Meanwhile, the Northwest Island faced heatwave conditions for 89% of the year, the highest among coastal areas.
Stuart Jones warned that even a small increase in temperature could disrupt marine ecosystems.
Warming sea waters can affect primary productivity in the ocean, impacting the organic matter production of phytoplankton or microalgae, which supports the marine food chain.
In the waters surrounding New Zealand, from 1998 to 2022, primary productivity in the ocean has shown a decreasing trend as sea temperatures rise in the warmer northern waters, while in the cooler southern waters, productivity tends to increase with rising sea temperatures.
