The basis of the ocean’s life-support lies in its microbiome – a vast community and network of microbes. A microbe is a microscopic organism, which may exist in its single-celled form or as a colony of cells. Just as the human microbiome determines the well-being of the human body, the ocean microbiome determines the well-being of the ocean. The ocean’s microbiome comprises millions of microorganisms, each playing a specific role in the ocean’s ecosystem. The latest mission onboard the research vessel, Tara aims to better understand this invisible population by mapping the ocean’s microbiome’s social network.
The health of the ocean’s microbiome is intrinsically linked to the health of the planet. The organisms that make up the microbiome are the first link in the ocean food chain, generating food through photosynthesis. This process also benefits humans. As trees and plants on land ingest carbon dioxide and expel oxygen, plankton and microalgae in the ocean do the same. Without this, the planet’s atmosphere would be overtaken by carbon dioxide.
The Tara research vessle. Photograph: The Tara Ocean Foundation.
“We want to try and sensitise scientists and the public to this microscopic world, so more research can take place.”
Assembling a biological jigsaw
The ocean’s microbiome is vast and complex, which has historically made it challenging to study. The microbiome represents over two-thirds of the ocean’s biomass, four times the accumulative biomass of all the insects on earth. Chris Bowler is the co-director of the Microbiome mission, ‘The mission is really aimed at getting a better idea of what these microbes are doing in the ocean, which of them does what and why they’re important.’ Scientists already have a good understanding of the microbiome’s composition. Still, there are significant gaps in knowledge about how the network of the microbiome operates. Due to the microbiome’s complexity, the task of understanding how the millions of microbes relate to one and another is a mammoth one. Chris describes it as ‘like assembling a giant jigsaw puzzle, but without having the picture.’
Setting sail in December 2020, the Tara embarked on the first leg of the mission. In total, the mission will incorporate 20 stopovers in 14 countries over two years. On route, ocean scientists onboard collect samples and data on the microbiome. Tara is the Tara Ocean Foundation’s main research vessel. At 30 metres long, Tara is relatively small for an ocean science research ship. However, her size means she has lower costs than larger boats, allowing for longer voyages.
First image: Collecting water samples. Second image: Lowering the rosette into to the ocean. Photographs: Tara Ocean Foundation.
Due to the microscopic size of the organisms, special techniques for collecting samples have been devised. Chris explains, ‘We use something called a Bongo net which we drag along behind the boat. The nets concentrate the plankton so we can take a sample.’ The mission will also collect samples from deep in the ocean, using a piece of machinery called a rosette. The rosette is an aluminium structure that can be submerged to depths of 1,000 metres, collecting up to ten samples at a time.
Throughout the two-years, 200 scientists from around the world will join the mission, many of them going onboard Tara to study particular ocean areas. Chris will be joining the crew next year when Tara reaches Antarctica, ‘Icebergs have many goodies in them in terms of nutrients that feed the microbes. I’m going to be studying how they interact with the water around them’.
Given its complexity, the mysteries of the ocean’s microbiome will not be uncovered in a single mission. Chris clarifies, ‘We want to try to sensitise scientists and the public to the importance of this microscopic world, so more research can take place.’ Ultimately, by understanding this world, Chris believes that we will have a better chance of living in harmony with nature, ‘By reconnecting the dots, we can find solutions.’
Helping towards our seven outcomes
A healthy and resilient ocean
where marine ecosystems are mapped and protected.