Plankton’s survival dependent on climate change
21 Jul 2016 by qwbdchbctt.d qwbdchbctt.d
Climate change could jeopardise the viability of phytoplankton responsible for a tenth of the oceans’ biomass, according to scientists.
Climate change could jeopardise the viability of phytoplankton responsible for a tenth of the oceans’ biomass, according to scientists. Scientists researched a particular group, called coccolithophorids, which cover themselves with calcium carbonate shields called coccoliths. They are created in a multitude of ways such as an impenetrable coat, sharp spikes, parasols against the sun or funnel-shaped light collectors. Researchers believe the calcifying plankton’s niche will become narrower in the future.
Professor Ulf Riebesell, co-author from the GEOMAR Helmholtz Centre for Ocean Research Kiel, said "Coccolithophorids have survived over 200 million years. But now it is questionable whether they are also able to withstand climate change.”
There are 200 coccolithophore species, producing up to 10% of ocean biomass, allowing the marine carbon cycle to continue. As the production of coccoliths is quite energy intensive, researchers believe the plankton’s ability to survive in the future hinges on competitors in the food web reacting to ocean change as well as energy expenditure by the microorganism.
Due to fossil fuel emissions, the amount of C02 dissolved in seawater is rising. Conversely, ocean acidification, caused by a reduction in sea pH, prevents calcification.
Professor Toby Tyrrell, co-author at the University of Southampton, said: “In the future ocean, the trade-off between changing ecological and physiological costs of calcification and their benefits will ultimately decide how this important group is affected by ocean acidification and global warming. There are signs that their distribution in the oceans is changing over time. If we understand better the costs and benefits of their distinguishing feature (coccoliths) then this should help us understand why their biogeography is shifting."
In order to understand the purpose of coccoliths, researchers from Germany, the UK, France and the United States analysed results from evolutionary history and cell biology studies as well as laboratory, field and modelling experiments.
The study was published in Science Advances.
