New Moana Project forecast predicts marine heatwave in the Chatham Islands

The Chatham Islands (Rēkohu) are expecting a strong marine heatwave this weekend as forecast by the Moana Project’s new marine heatwave forecasting tool.

Located approximately 840 kilometers east of New Zealand’s South Island, the Chatham Islands are an archipelago of 10 islands that host fisheries for rock lobster, pāua and blue cod, which are a valuable part of the Chatham Islands economy and significant contributor to overall fishery exports from New Zealand.

“A recent blocking pattern of high pressure has created optimal conditions for a marine heatwave to form in the waters surrounding the Chatham Islands,” explains Dr Robert Smith from the University of Otago. “Marine heatwaves can occur towards the end of the summer season in New Zealand, when blocking high pressure weather systems reduce surface wind speeds and inhibit ocean mixing.”

Difference between forecasted sea surface temperatures and the long-term average for this time of year. Red shading indicates that the ocean is currently warmer than normal; blue that it is colder.

“Extreme events such as the forecasted marine heatwave can have severe and long-lasting impacts on marine ecosystems and fisheries. There are potentially important consequences for the local community which depend on the ecosystem services,” explains Moana Project Science Lead Dr Joao Souza from MetOcean Solutions.

The new marine heatwave forecast is available at www.moanaproject.org/marine-heatwave-forecast and more information about the forecast can be found at https://www.moanaproject.org/news/nzs-first-marine-heatwave-forecast-live.