The pan-European scientific TREC expedition returns after 18 months of sampling on land and at sea

Starting in spring 2023, the scientific TREC expedition (TRaversing European Coastlines) is an international exploration of life in water, sediment, soil, and air along Europe's coasts. Its aim: to understand how coastal ecosystems function, influence each other, and adapt to natural changes and the impact of human activities. Scientists will now analyse the collected data to study, amongst many other things, how climate change, chemical pollution, biodiversity decline and antibiotics resistance spread can be monitored and understood  at the molecular and cellular level.

TREC was led by EMBL, in partnership with the Tara Ocean Foundation and the EMBRC, in collaboration with over 90 scientific institutions. While the scientists on the Tara schooner sampled at sea, EMBL’s mobile laboratories supported the collection and immediate analysis of samples on land. Together, this approach enabled the exploration of biodiversity, certain key coastal species and habitats, as well as the molecular and cellular mechanisms that enable living organisms to adapt and evolve in response to environmental and societal change.

Collaboration lies at the heart of TREC, with numerous national and international partners – in particular, 42 European marine stations, from Portugal to Estonia and from Finland to Greece – being part of the expedition. 

TREC teams together in Lorient: The Tara schooner returned to its home port of Lorient, France, on Saturday 5 October during a weekend of public celebrations. Participants were also able to see and visit EMBL's Advanced Mobile Laboratory (see photo) – a unique laboratory on wheels designed for the expedition. The event in Lorient marked the end of the sampling phase of TREC. Credit: Massimo del Prete/EMBL

An international exploration of life on Europe's coasts

The innovative aspect of the expedition is the study of the interconnectivity of organisms – with each other and with environmental factors – in their natural environment rather than in the controlled conditions of a laboratory. Throughout the expedition, scientists gathered information on the diversity of living organisms, particularly those that are invisible. TREC involved sampling ecosystems (including viruses, bacteria, protists, algae, plants and animals), exploring organisms in communities and on a population scale, understanding the molecular basis of their interactions and investigating their contribution to shaping their environment. In addition, data on environmental parameters were collected in a systematic and standardised way, covering a wide range of human-made and natural factors, such as the presence of pollutants, antibiotics, pesticides, or hormones, but also temperature, pH, salinity, oxygen levels, and certain geophysical parameters. 

“The data, knowledge, and scientific networks that have been created through the TREC – Traversing European Coastlines – expedition will undoubtedly lead to innovative ideas through this voyage of discovery and will help develop new strategies to protect coastal environments from global challenges such as climate change, pollution, and biodiversity depletion.”

“It's an enormous satisfaction for the entire Tara Ocean Foundation team to bring its 13th expedition, Tara Europa, to a close. It was an expedition as close as possible to the territories, as close as possible to us, to try and put numbers on our direct impact on the living beings of our European coastlines. To describe this marriage between land and sea is to bring us all closer to the Ocean, and to do it with a hundred laboratories over such a vast territory is an achievement.”

An expedition for science and society 

Each of the 115 sampling points was coordinated in detail between the land and sea teams to allow collection of samples along transects. At selected stops, EMBL’s Advanced Mobile Laboratory additionally enabled researchers from the local marine biological stations to analyse samples and prepare them for storage immediately after collection. 

The TREC expedition brought together researchers from all over Europe. Their collaborative work and shared knowledge will help provide the scientific basis for better understanding and managing societal issues, ranging from the effects of multiple forms of pollution to climate disruption on these key ecosystems. The project further helps to understand major societal challenges such as antibiotic resistance by exploring how the genes involved can spread between organisms and across ecosystems.

The TREC teams applied more than 200 of the most advanced protocols and technologies for a unique and comprehensive exploration of ecosystems, particularly at the molecular and cellular levels. They collected over 70,000 samples that will help to reveal unknown coastal biodiversity and new biological functions in land and sea ecosystems. 

 The samples offer a wealth of new information and discoveries: for example, we are likely to discover, on average, hundreds of new microbial species at each sampling site, and new types of symbiotic relationships between species. Institutes all across Europe will be able to use the sampling data collected for future comparative studies. In addition to being analysed by TREC partners and collaborators, all data produced will be freely accessible to the international scientific community, and will be used to build a reference database that will enable researchers to study changes in coastal ecosystems for years to come. 

 As another next step in the TREC project, scientists will determine how the approaches of this extraordinary expedition can be applied to other ecosystems, such as lakes and rivers. 

Promoting collaboration, scientific training, and public engagement 

While EMBLs fleet of mobile laboratories researching land and shallow water arrived at their base at EMBL Heidelberg already late summer, the Tara schooner, sampling offshore, returned to its home port of Lorient, France, on Saturday 5 October during a weekend of public celebrations. Participants were also able to see and visit EMBL's Advanced Mobile Laboratory – a unique laboratory on wheels designed for the expedition, which will now return to EMBL’s headquarters in Germany. This event in Lorient marked the end of the sampling phase of TREC.

All in all, the pan-European expedition:

• created value for the scientific community and society by bringing together more than 150 teams from a variety of disciplines, belonging to over 90 institutions in 21 European countries;
• provided advanced knowledge and technologies for the benefit of the scientific community in Europe and worldwide; 
• engaged the general public in debates and discussions to raise awareness of the role of science and fundamental knowledge in society; 
• inspired the next generation of scientists by raising awareness among students and teachers of the importance of understanding life on our planet.

SOURCE: European Molecular Biology Laboratory (EMBL)