Acid oceans are shrinking plankton, fuelling faster climate change
August 26, 2019 3.59pm EDT
The Conversation
By Katherina Petrou
Senior Lecturer in Phytoplankton Ecophysiology, University of Technology Sydney
And Daniel Nielsen, University of Technology Sydney
Increasingly acidic oceans are putting algae at risk, threatening the foundation of the entire marine food web. Our research into the effects of CO₂-induced changes to microscopic ocean algae – called phytoplankton – was published today in Nature Climate Change...In our study we discovered increased seawater acidity reduced Antarctic phytoplanktons’ ability to build strong cell walls, making them smaller and less effective at storing carbon. At current rates of seawater acidification, we could see this effect before the end of the century.
...Diatoms use dissolved silica to build the walls of their cells. These dense, glass-like structures mean diatoms sink more quickly than other phytoplankton and therefore increase the transfer of carbon to the sea floor where it may be stored for millennia....The more acidic the seawater, the more the diatom communities were made up of smaller species, reducing the total amount of silica they produced. Less silica means the diatoms aren’t heavy enough to sink quickly, reducing the rate at which they float down to the sea bed, safely storing carbon away from the atmosphere.
On examining individual cells, we found many of the species were highly sensitive to increased acidity...Most alarming, many of the species were affected at ocean pH levels predicted for the end of this century, adding to a growing body of evidence showing significant ecological implications of climate change will take effect much sooner than previously anticipated.
...The only course of action to prevent catastrophic climate change is to stop emitting CO₂. We need to cut our emissions soon, if we hope to keep our oceans from becoming too acidic to sustain healthy marine ecosystems.
More here
https://theconversation.com/acid-oceans-are-shrinking-plankton-fuelling-faster-climate-change-121443
Meanwhile one empty chair at G-7 climate meeting: Trump’s
