What can microscopic microbes tell us about climate change?

Dr Mark BrownA University of Newcastle researcher has participated in a projectthat has recorded more than 175,000 tiny microbes that provide an unprecedented baseline against which to measure the effects of climate change and human activities.

Invisible to the naked eye, microbes constitute almost 98 per cent of the ocean’s biomass and are responsible for keeping the marine ecosystem healthy.

A paper recently published in Nature journalled by University of Newcastle’s Dr Mark Brown reveals the vast diversity of microbes and provides new knowledge about their environmental behaviour.

The unparalleled dataset is the result of an ongoing collaborative initiative involving 18 Australian universities, Commonwealth agencies and research institutes, which recorded more than 175,000 unique species of microbes at seven sites around Australia’s coastline and into the Southern Ocean.

Dr Brown said microbes in the ocean are possibly the most important organisms for maintaining the world as a healthy, inhabitable planet.

“Similar to the links between human health and the human microbiome, ocean health is largely controlled by its microbial inhabitants. Forming the foundation of the entire ecosystem, microbes provide food for all other marine life and produce half the oxygen we breathe.

“In this regard, they function in a similar way to organs in a human body. Some microbes act as the lungs of the ocean responsible for gathering and distributing oxygen to the planet, while others act as the gut or liver to detoxify impurities within the water and control the flow of nutrients.”

Scientists developed the project in 2012 to address a lack of data surrounding marine microbial communities and their changes over time.

“We were extremely concerned that no baseline existed to compare microbial activity against. Prior to this project, there was no information detailing what the microbes were like around Australia, which made it difficult to know how they might have changed over seasons or years,” Dr Brown said.

What can microscopic microbes tell us about climate change? Marine diatom Thalassiosira – Image supplied by Penelope Ajani from the University of Technology, Sydney

Marine dinoflagellate Ceratium – Image supplied by Penelope Ajani from the University of Technology, Sydney (1).

Marine dinoflagellate Certium furca – Image supplied Penelope Ajani from the University of Technology, Sydney.

Mixed marine diatoms – Image supplied by Penelope Ajani from the University of Technology, Sydney

TweetFacebook Microbes of the oceanEmploying filtration methods similar to those used to purify drinking water, scientists collected microbe samples each month at multiple depths, ranging from surface water down to 100 metres.

“Different microbes live in different parts of the ocean and they have evolved to occupy every conceivable niche. Different species can be found living on deep-sea hydrothermal vents, in sediments, at varying depths and in warm or cold water,” Dr Brown said.

The material extracted from the filters was then genetically sequenced using technology only available in the last few years, which provided a snapshot of the DNA blueprint of the microbial inhabitants within each sample.

Forming an enormous genetic database, this first data release tracks over 200 million records of more than 175,000 unique species of microbes.

Dr Mark Brown from the University of Newcastle and Martin Ostrowski from Macquarie University.

Co-author, Dr Martin Ostrowski from Macquarie University, said the project team is now building models to predict where organisms will live in the future and what functions they will carry out.

“We can now use the baseline data we have collected to make models that tell us how microbes respond to different environmental conditions and how we expect them to change given future climate projections.

“The primary production and carbon use by marine microbes determines how much food is provided to the rest of the food chain, so our forecasts will be incredibly relevant to scientists but also to industries such as fisheries and tourism.”

The DNA sequence data is available to the public and can be accessed via the Bioplatforms Australia website.

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