Nav: Home

Ocean warming and acidification impact on calcareous phytoplankton

July 12, 2016

Two new studies recently published in Limnology & Oceanography and Biogeosciences report that ocean warming may exacerbate the impacts of ocean acidification on calcareous phytoplankton, and its evolutionary success and physiological performance will be hampered.

The oceans have absorbed more than a quarter of the human-made carbon dioxide (CO2) in the last century, changing the chemistry of the ocean and resulting in 'ocean acidification'. A rise in average temperatures is also warming the sea surface. The risks posed by warming and acidification are expected to become more acute in the next decades, as CO2 emissions into the atmosphere are increasing.

Coccolithophores is a very abundant calcifying phytoplankton group which plays a major role in the biogeochemical cycle and in the regulation of the global climate. These tiny algae which measure less than one hundredth of a millimeter "form the basis of the aquatic trophic chain, and through calcification and photosynthesis coccolithophores regulate atmospheric and oceanic CO2 levels", says Dr Patrizia Ziveri, ICREA researcher at ICTA-UAB and author of the study. The effects of acidification - and in particular warming - are rarely considered for the organism itself, and there is very little knowledge on how warming and acidification combined may affect the physiological performance or evolutionary success of coccolithophores.

Therefore, it was the aim of the team to investigate not only how temperature affects the impact of acidification on the cocolithophores, but also on the sinking rate and coccolithophores morphogenesis. A culture experiment was conducted on Mediterranean Sea and North Pacific Ocean strains of Emiliania huxleyi, the most abundant coccolitophore species.

Using scanning electron microscope (SEM) imaging, the researchers show in their study that there will be an increase in the percentage of malformed and incomplete coccoliths in a warmer and more acidified ocean. This will hamper the evolutionary success of these calcifiers and their role in regulating atmospheric carbon.

Since coccolithophores need to stay in the photic zone of the oceans, their sinking velocity affects their survival rate. Nothing is known about the response of coccolithophores to acidification and warming in terms of sinking rate, because it had been impossible to estimate sinking rate in the framework of a typical laboratory experiment. The team used a novel approach to calculate sinking rate from cell-architecture and showed that an increase in temperature will lead to an increase in sinking rate. Hence, the faster sinking for the organism itself has an impact on future global carbon cycling and therewith on atmospheric levels of CO2 and global climate.
-end-
This work was funded by the European Union's Seventh Framework Programme under grant agreement 265103 (project MedSeA), the European Research Council (ERC grant 2010-NEWLOG ADG-267931 HE), the Natural Environment Research Council (Grant NE/N011708/1) and the Generalitat de Catalunya (MERS, 2014 SGR - 1356). This work is contributing to the ICTA-UAB 'María de Maeztu Unit of Excellence' (MinECo, MDM2015-0552).

Universitat Autonoma de Barcelona

Related Ocean Acidification Articles:

New threat from ocean acidification emerges in the Southern Ocean
Scientists investigating the effect of ocean acidification on diatoms, a key group of microscopic marine organisms, phytoplankton, say they have identified a new threat from climate change -- ocean acidification is negatively impacting the extent to which diatoms in Southern Ocean waters incorporate silica into their cell walls.
Coral skeleton crystals record ocean acidification
The acidification of the oceans is recorded in the crystals of the coral skeleton.
Ocean acidification boosts algal growth but impairs ecological relationships
Shrimp fed on marine algae grown in acidic water do not undergo a sex change that is a characteristic part of their reproductive life-cycle, report Mirko Mutalipassi and colleagues at Stazione Zoologica Anton Dohrn in Italy in a study publishing June 26 in the open-access journal PLOS ONE.
Ocean acidification 'could have consequences for millions'
Ocean acidification could have serious consequences for the millions of people globally whose lives depend on coastal protection, fisheries and aquaculture, a new publication suggests.
Southern Ocean acidification puts marine organisms at risk
New research co-authored by University of Alaska indicates that acidification of the Southern Ocean will cause a layer of water to form below the surface that corrodes the shells of some sea snails.
More Ocean Acidification News and Ocean Acidification Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Erasing The Stigma
Many of us either cope with mental illness or know someone who does. But we still have a hard time talking about it. This hour, TED speakers explore ways to push past — and even erase — the stigma. Guests include musician and comedian Jordan Raskopoulos, neuroscientist and psychiatrist Thomas Insel, psychiatrist Dixon Chibanda, anxiety and depression researcher Olivia Remes, and entrepreneur Sangu Delle.
Now Playing: Science for the People

#537 Science Journalism, Hold the Hype
Everyone's seen a piece of science getting over-exaggerated in the media. Most people would be quick to blame journalists and big media for getting in wrong. In many cases, you'd be right. But there's other sources of hype in science journalism. and one of them can be found in the humble, and little-known press release. We're talking with Chris Chambers about doing science about science journalism, and where the hype creeps in. Related links: The association between exaggeration in health related science news and academic press releases: retrospective observational study Claims of causality in health news: a randomised trial This...