In the first of my blogs about heatwaves, I focused on the heatwaves that are occurring on land more and more often and the effects these are having on terrestrial life forms, including humans.
In this blog, I will describe the effects of heatwaves on the oceans, which have doubled in the last 30 years. Up till now, perhaps we have been unaware that heatwaves do affect the oceans and the life that in them. In other blogs, and in my book, I have talked about the destruction of coral as the seas warm, causing coral bleaching. It is also known that, after the 2016 heatwave in Australia, one third of the coral in the Great Barrier Reef died. Many of the beautiful fish who live in coral reefs, and are dependent on them, will be affected by the death of corals.
Fish in a coral reef
In yet another blog, I have referred to how global warming is affecting the gender of sea turtle eggs, developing in the hot sands where they have been laid, so that now the majority (99%) of the hatchlings born in Northern Australia are female.
Swiss scientists have been recording sea water temperatures over the period 1982-2016 and have found that the number of ocean heatwaves has doubled. Marine heatwaves can last for several days, and even weeks, as water absorbs heat more readily than air and releases it more slowly. Dr Thomas Frölicher, of the University of Bern in Switzerland, is the climate scientist who has conducted this study. He believes that the trend of increasing ocean heatwaves will only accelerate with time. Prolonged periods of extreme heat in the oceans can damage kelp forests as well as coral reefs, and harm fish and other marine life. Some sea creatures have evolved to survive in a very narrow band of temperatures compared to creatures on land. Some free swimming fish can move to other places when the sea becomes too hot for them but, with fixed organisms like coral and kelp forests, there is no opportunity to move.
If the plankton in the sea, as well as kelp forests, are affected by warming temperatures, many marine creatures will lose their main source of food.
Further details of the study, published in Nature, can be found on the following websites: