As a result of the COVID-19 pandemic, most people are familiar with PCR tests. But many would be surprised to find that, as well as indicating illness or pregnancy, these rapid tests can help reveal the biological secrets of marine habitats. 

PCR tests are one method researchers use to find and analyse environmental DNA (eDNA) in water or biomass samples. “And this can very quickly give you an idea of the diversity in a site where you don't actually have a specimen you can morphologically identify,” says Saara Suominen, Scientific Officer at the Ocean Biodiversity Information System and UNESCO – Intergovernmental Oceanographic Commission. 

A revolutionary approach

Using eDNA for biodiversity is “revolutionary,” says Suominen, because of its huge potential to collect high levels of data that couldn’t be captured through traditional methods. This helps researchers paint a picture of what lives in certain marine areas, including cryptic species or those hard to identify because of their life stage, such as larvae. “It opens up a completely different way of analysing the environment,” she says.

Invasive species 

Identifying the presence of animals you can’t see can be crucial for early detection; for example, in the case of invasive species, she says: “Effective environmental monitoring can help prevent millions of euros of costs later on.” When invasive species or pathogens take over from local organisms, it can be incredibly expensive to mitigate the catastrophic consequences of an outbreak. 

“A good monitoring system will help catch that early on,” she says, so the problem can be eradicated or prevented altogether. Understanding where and how species are coming into an environment can also inform management actions. 

An interconnected system

When researchers sequence the DNA of a species, they compare and contribute information to reference databases: catalogues which link DNA sequences to a species’ name – which is called barcoding. 

“But, usually, these reference databases are incomplete,” says Suominen, and may have geographical limitations: “In many cases, tropical areas where most of the biodiversity is are the least barcoded or least analysed. So we miss a lot of that information.”

Currently, there’s no central eDNA database. Disparate datasets from different countries, companies or academics “don't come together in one place very well so it's hard to have an overview of what's going on,” says Suominen. Researchers need “an interconnected system where everything can talk with each other: all the systems can work together,” she adds. 

eDNA Aqua Plan, a project led by EMBRC

eDNA Aqua Plan – a European project led by EMBRC – is trying to create a roadmap of how to bring this data together, harmonise it and put it into a usable format. “The overarching goal is to build synergies between different sources of eDNA data,” explains Suominen.

The project aims to remove silos by creating an efficient data ecosystem that can be easily accessed and used by anybody. It will look at how data is generated, submitted, stored, analysed and accessed as well as how different sources are linked together. 

A biodiversity weather forecast 

The aim is to create a high capacity, automated system to act as “a biodiversity weather forecast” that gives a holistic picture of what’s happening around the world, says Suominen. 

In a perfect world, this interoperable data set and barcoding system could enable researchers to analyse a sample then see on a map where and when that species had been found before – helping them to spot new species in an area before they become problematic. It could also allow scientists to see if animals move to higher latitudes as waters warm due to climate change. 

The need to understand how biodiversity responds to our changing climate is vital, says Suominen, for research, monitoring and policy: “It's about understanding the challenges from our environment changing around us – such as invasive species or biodiversity loss – so we can find solutions.”

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When you think of World Ocean Day, you might imagine sharks, whales, dolphins, and turtles – charismatic animals that beguile us with their intelligence, ingenuity, and fascinating behaviours. 

But the vast ocean is teeming with life and even the tiniest organisms play their part in keeping our planet healthy.