This pressure is already creating conflicts in terms of use, which will be further exacerbated by the consequences of climate change (EFESE 2018). Although continental waters only represent 0.8% of the world’s total surface area, they are home to almost 6% of known species and a third of vertebrate species. Moreover, the reduction in biodiversity is greater than in other systems: -55%, compared to -25% for marine and land species (other than micro-organisms) between 1970 and 2000 (source: WWF-UNEP-WCMC).

Continental aquatic environments therefore represent ecosystems for which the stakes in terms of the loss of  biodiversity are very high. This erosion of biodiversity, which is faster in CAEs than in other systems (30% additional loss of biodiversity), can be explained by two factors: their intrinsic spatial characteristics and high anthropogenic pressure. With regard to the first point, patch distribution in lakes and ponds, as well as the hierarchical and unidirectional structure of fresh water ecosystems means that exchanges between isolated populations are much more difficult than for populations which live in multidirectional systems, or patch systems, for which the matrix has a certain number of corridors. Thus, the endemic nature of species is greater there than in other environments and the risk of consanguinity higher.

This risk has largely been exacerbated by numerous insurmountable barriers erected on waterways, limiting exchanges and therefore genetic diversity. Furthermore, these barriers modify the habitat, hydrology, geomorphology and, above all, ecological continuity, thus reducing the ability to host and sometimes resulting in the pure and simple disappearance of a population, even a species.

Fragmentation is not seen as being one of the main threats on aquatic biodiversity as identified by Strayer & Dudgeon (2010). However, its consequences, the destruction or deterioration of the habitat and local modifications in hydrological systems, all appear alongside overexploitation, water pollution and invasive species. These threats must be added to increased water temperatures or modified precipitation and flow system linked to climate change. These are all major changes occurring on a global scale, which are supposed to accelerate the erosion of biodiversity in continental aquatic environments.

Threats to biodiversity in continental waters interact, making understanding their consequences on populations and communities extremely complex. Taking into account this complexity is therefore a real challenge. Thus, to evaluate and foresee the consequences of (local and global) threats to aquatic biodiversity, their potential interactions have to be taken into consideration.

To evaluate the trends and identify the potential factors involved, data collected over the long-term is needed, enabling environmental changes to be related to species and target populations. To go further, beyond the correlations highlighted, it is also necessary to apply experimental approaches. It is through the controlled processing of different factors that interactions can be studied and the mechanisms at work identified.

The LIFE RI aims to make available to the scientific community tools, data and means adapted to such stakes. Its installations and technical/technological means, skills, long-term databases (35-50 years) and collections are fully suited to being included in both scientific and societal challenges relating to this issue.

The target environments include bodies of water (lakes or ponds) and waterways (upstream from estuaries).

With regard to species, LIFE’s skills cover fish, as well as all the biocenosis: microbial communities, plants (micro/macrophytes), zooplankton and invertebrates.

LIFE’s numerous installations, combined with its personnel’s skillset, enable experiments to be envisaged in the short and medium-term, evaluating the combined action of different environmental factors on individuals, populations and communities.

Long-term surveys and collections provide precious data, namely to predict the effects of climate change.