Antinuclear

Australia’s marine heatwaves provide a glimpse of the new ecological order, Guardian, Joanna Khan, Tue 5 Mar 2019  Receding kelp forests, jellyfish blooms and disruption to fisheries are just some of climate change’s impacts on the ocean, s bushfires raged across Tasmania, Victoria and New Zealand, and north Queensland faced a massive cleanup after unexpected flooding, a different extreme weather event was silently forming in the Tasman Sea over summer.For the second year in a row, a stubborn high-pressure system over the Tasman Sea was warming the surface of the ocean to above-average temperatures, forming a marine heatwave, wreaking destruction and providing a glimpse of the new ecological order in the marine Anthropocene. Globally marine heatwaves are becoming more frequent and prolonged and affecting biodiversity, according to new research published in Nature Climate Change this week.

In the summer of 2017-18, the intense marine heatwave was combined with a land-based heatwave, together covering four million sq km. Scientists foundthe extreme weather event caused unprecedented loss of glacial ice in the New Zealand Southern Alps, changes to wine-grape harvests, and major disruption of marine ecosystems including kelp habitat loss, new species invasions and fisheries season changes.

This year the National Institute of Water and Atmospheric Research in New Zealand reported that sea surface temperatures in the Tasman were again above average.

Like coral reefs and tropical rainforests, the ocean suffers the slow torture of climate change peppered with high-intensity hits from extreme weather.

A window into the future

Marine heatwaves are generally out of sight and out of mind until one gets so bad it becomes impossible to ignore, says CSIRO research scientist Alistair Hobday.

A marine heatwave happens when the ocean temperature is much warmer than usual for the time of year from sunlight heating the surface water or warm water being brought via ocean currents – or both.

Climate change is causing marine heatwaves to happen more frequently and with more intensity. There may not be scorched earth or destroyed homes left in its wake, but a marine heatwave impacts our future in different ways – and serves as a warning. ……… https://www.theguardian.com/environment/2019/mar/05/australias-marine-heatwaves-provide-a-glimpse-of-the-new-ecological-order