An extensive catalogue of ocean life has been unveiled by university researchers in Saudi Arabia.
The index provides a baseline for monitoring the effects of global warming, pollution and other human-induced changes to marine environments, enabling scientists to form targeted research questions about specific habitats and microbial classes.
It also offers a new perspective to predict the consequences of changes driven by climate change, such as ocean warming, deoxygenation and acidification.
The comprehensive database, named the KMAP Global Ocean Gene Catalogue 1.0, is a world first, mapping the genetic blueprint of a myriad marine organisms, predominantly microbes.
“The [atlas] is a leap towards understanding the ocean’s full diversity, containing more than 317 million gene groups from marine organisms around the world,” said lead author Elisa Laiolo of the King Abdullah University of Science and Technology (Kaust) in Thuwal, Saudi Arabia.
“The catalogue focuses on marine microbes, which greatly impact human lives through their influence on the ocean’s health and the Earth’s climate.”
Prof Carlos Manuel Duarte, a marine ecologist at Kaust and the study’s senior author, highlighted the significance of the atlas's potential in addressing climate change.
He emphasised its ability to pinpoint genes that could be instrumental in the CO2 reduction processes. “[It does so] by identifying genes that can be harnessed to catalyse reactions to efficiently remove CO2 from the atmosphere or the ocean, of which the catalogue contains thousands,” Prof Duarte said.
The oceans, covering more than 70 per cent of Earth's surface, are teeming with life, much of which remains unexplored and mysterious.
The new catalogue encompasses 317.5 million gene groups gathered from more than 2,100 ocean samples.
But what are marine microbes?
“Marine microbes are unicellular organisms that represent the bulk of life in the ocean, by number and mass, and are responsible for all the cycling of elements, such as carbon, nitrogen and phosphorus,” Prof Duarte explained.
These processes are fundamental in maintaining the ocean's key biological processes.
This includes the balance of greenhouse gases, which are vital for climate regulation, and the production that underpins global fisheries.
What can this massive catalogue of marine genes actually tell us about ocean life?
“It tells us that the global ocean genome is dynamic and constantly evolving, that bacteria contribute to the bulk of genomic diversity across the ocean, but that fungi are far more important than realised in the twilight zone – the layer between 200-1,000 metres deep – and that viruses have a very important contribution to the genomic repertoire of the ocean,” said Prof Duarte.
What sets the new index apart is its level of detail.
Each gene group is classified according to taxonomy, revealing the organism type or species to which it belongs.
The function of the encoded protein by each gene, its geographical origin and the depth from which the sample was collected were also documented.
The creation of this catalogue involved a complex process of DNA sequencing, utilising a technique known as shotgun sequencing.
Shotgun sequencing is a method scientists use to break down and analyse DNA from the ocean, allowing them to quickly read and catalogue the genetic information of many organisms at once, like creating a detailed map.
This approach allows for quick and efficient breakdown of the DNA in each sample, assembling a "metagenome" – a collection of genetic information from all organisms present in a sample.
Practical applications of the ocean gene atlas
The KMAP Global Ocean Gene Catalogue 1.0 offers insights into the diversity and functions of ocean life, particularly in understanding how these organisms adapt and interact with their environment.
It also sheds light on the distribution of microbes across various depths and geographical locations.
Beyond its scientific value, the catalogue has practical applications in several fields, including biotechnology, pharmaceuticals and environmental monitoring.
For example, it can help in the discovery of new compounds for drug development or in tracking the effect of climate change and human activities on marine ecosystems.
“The industrial use of marine genes propels marine biotechnology, which is a new industry, as sequencing is only possible since over a decade ago, and generates a volume of $6 billion per year, with this amount doubling every six years,” said Prof Duarte.
“The Ocean Gene Catalogue allows the exploration of the huge diversity of genes in search for understanding of the evolution of life, the functioning of the ocean and genes that code for enzymes of industrial use: food industry, pharma, cosmetic, environment and energy sectors.”
He outlined the two primary challenges related to the catalogue.
Firstly, the daunting task of identifying specific genes of interest within the hundreds of millions available in the catalogue and secondly, the complex issue of gene ownership.
The latter challenge remains largely unfulfilled, despite advancements made under international frameworks such as the Convention of Biological Diversity (Nagoya Protocol) and the Law of the Sea (Biodiversity Beyond National Borders agreement).
This project also lays the groundwork for future research, providing a baseline for monitoring ocean biodiversity.
