Bay of Plenty Marine Temperatures Rising

A major national environment report has highlighted heat as a "stressor" for marine organisms in the Bay of Plenty.

Our environment 2025 is the Ministry for the Environment and Stats NZ’s latest three-yearly update on the state of New Zealand’s environment.

It found marine heatwaves caused "unusual fish migrations, severe bleaching and necrosis of sponges, large losses of farmed salmon and southern bull kelp (rimurapa)".

According to the report, heat likely contributed to the mass mortality of blue penguins (kororā) in the Bay of Plenty.

NIWA physical oceanographer, Erik Behrens told 1XX News, "in the Eastern Bay of Plenty, water temperatures are at least one degree warmer than we would expect at this time of year".

"It has influences on varying organisms - penguins or also fish - which encounter heat stroke, basically."

He said extreme marine heat temperatures had impacts like die-off.

In January 2018, hundreds of shearwaters, petrels, prions, shags and penguins, including dead poisonous pufferfish, were reported to have washed up along Mount Maunganui beach, Pāpāmoa beach, Pukehina beach, and Waihi beach.

Behrens said compared to the Pacific and other countries "New Zealand's ocean is warming at two to three times the global rate and is a hotspot for ocean warming on a global scale."

NIWA physical oceanographer Erik Behrens says the large warming around the North Island is unusual and does not align with the pattern which we would typically expect during El Nino. Image / NIWA