Marine heatwaves

A marine heatwave is a period of prolonged warming of the sea surface temperatures that can extend thousands of kilometres. For example, some heatwaves in Aotearoa New Zealand have spread across most of the Tasman Sea.

What effect do they have?

Marine heatwaves can cause mass-mortality of marine life, disturb ecosystems, and pose serious problems for fishing and aquaculture. They also contribute to land heatwaves and climate extremes across the country. Their effects can exacerbate the multiple stressors that coastal marine ecosystems already face, including a warming sea, ocean acidification, sediment inputs, and poor water quality.

How are NIWA exploring marine heatwaves?

NIWA’s is focused on enabling Aotearoa New Zealand to understand, anticipate and manage the impacts of marine heatwaves on coastal ecosystems. Our research encompasses the critical spectrum of domains related to marine heatwaves in Aotearoa-New Zealand’s coastal waters. This includes climate modelling, physical oceanography, ecology and ecophysiology, biogeochemistry, and social and adaptation-focussed science.

Why study this area?

Aotearoa New Zealand has unique, productive and biodiverse marine ecosystems and ecosystem services, that support a valuable economy. We urgently need information to guide the sustainable management of Aotearoa-New Zealand’s marine biodiversity and ecosystems and build resilience against the challenges they face from heatwaves. 


Marine heatwave conditions: left – today, right – 2100 (NIWA, Deep South Challenge) 


Principal Scientist - Marine Ecology