Biogeography for identifying microbial bioindicators reporting ecological status of coastal wetlands in the SUDOE area
Résumé
Coastal wetlands represent environments with important ecological issues, composed of a vast
diversity of habitats and species and supporting many human activities. However, these
environments are in sharp decline, and their deterioration threatens the benefits they provide.
Indeed, climate change and human activities tend to modify the functional balance of these
environments challenging the management choices. At present, ecosystem-based decision
support tools are urgently needed to define management levers for preserving these
environments and their biodiversity. It is in this context that the European BIOMIC project
(Interreg SUDOE) aims to address this need by developing a toolbox of microbial and trophic
bioindicators to assess the ecological status of coastal areas. BIOMIC proposes a biogeography
analysis covering 53 coastal wetlands in the SUDOE area (Mediterranean and Atlantic coasts:
France, Spain and Portugal) for the development of benthic microbial bioindicators based on
environmental DNA approaches. A broad variety of environments have been selected,
considering the representativeness and variety of coastal environments of the SUDOE area, and
covering coastal management problems, coastal area rehabilitation and biodiversity protection.
Microbial communities (bacteria, archaea, fungi) were characterized through 16S and 18S rRNA
genes sequencing, and physicochemical parameters and pollutants (metals, pesticides,
hydrocarbons) content were determined. Relationships between microbial communities and
environmental parameters were evaluated via multivariate analyses including linear
discriminant analyses effect size (LEfSe), indicator values (IndVal), threshold indicator taxa
analysis (TITAN), MicrogAMBI and network analyses. Potential microbial bioindicators for
monitoring the ecological quality of ecosystems in the SUDOE area were identified. Ultimately,
BIOMIC aims to implement the use of these bioindicators in existing environmental quality
assessment regulations, in order to provide an integrative toolbox combining different food web
communities in water and sediment compartments. The identified bioindicators will then be
validated by seasonal monitoring and mesocosm experiments.