Monday, March 4, 2024

Fishing for marine heatwave data

New Zealand recorded its most impactful marine heatwave in history in 2022 – and it’s just the beginning, the 2022 Seafood NZ Conference in Nelson has heard.

Speaking to 300 delegates at the seafood industry annual conference, Moana Project Manager, marine ecologist Dr Malene Felsing said that despite being in the tail end of winter, marine heatwaves were continuing to affect many New Zealand coastal areas.

She said the Bay of Plenty has already recorded the most extended marine heatwave seen in New Zealand waters, a heatwave that has now been ongoing for nine months, according to a new Moana Project recording the duration of marine heatwaves in New Zealand.

Fiordland saw the most impactful marine heatwave on record in 2022, with temperatures reaching almost 5 degrees above normal.

To find about more, MetService researchers, through the Ministry Business Innovation and Employment (MBIE) funded Moana Project collated New Zealand’s most extensive ocean temperature data, using sophisticated sensors on commercial fishing gear.

“We have over 250 sensors attached to commercial fishing gear, from inshore cray potters to deepwater trawlers in the Southern Ocean, sending back ocean temperature and depth data,” Dr Felsing said.

Dr Malene Felsing.

“These sensors collected an astounding 4.3 million observations last year, 700,000 alone in the month of June. Altogether, the sensors have been collecting underwater data for a combined time of over 12 years.

“In 2020 New Zealand had almost no real-time observations of coastal ocean temperatures, and now we have millions – thanks to the fishing industry.”

The ocean temperature data collected will be incorporated into MetService ocean forecasts to improve accuracy.

“From the more accurate models we get better forecasts, including for marine heatwaves, and this is vital information will help us prepare for and mitigate climate change impacts,” said Dr Felsing.

“Fishers get their data back, so they know exactly what the temperature was where they fished.”

This, along with the improved forecast and warning of marine heatwaves, is the first step in helping fishing and aquaculture industries better prepare for ocean warming, she said.

“Looking to the future, Moana Project research shows that average sea temperatures could increase by 1.4 degrees by 2060, and by almost 3 degrees by the end of the century. This has wide implications for marine life, including fisheries and aquaculture. This means that by mid-century we may be facing 260 days of marine heatwaves per year, increasing to 350 days by 2100.”

Figure showing that the Bay of Plenty has been under marine heatwave conditions for more than nine consecutive months. Red shading indicates marine heatwave conditions.

“We can’t measure everything, everywhere, all the time – that is why we need accurate models, coupled with real-time data to forecast both short and long-term temperatures. The Moana Project is unlocking the seas around NZ, providing vital data and information for all industries that use our seas,” said Dr Felsing.

The Moana Project is a five-year research project that will come to an end in September 2023. The project is currently looking at ways to further the ocean observation and forecasting beyond the project’s completion.

The Seafood NZ Conference winds up in Nelson today.

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