Overview
The Research Program in Nouvelle-Aquitaine
Stygofauna refers to all species that complete their entire life cycle in underground aquatic environments (free-flowing underground rivers and aquifers, underflows of watercourses).
Program Background and Objectives
In 2012, DREAL Poitou-Charentes commissioned Poitou-Charentes Nature to undertake a study whose primary objective was to better understand the ecology and distribution of the Gallaselle, a small endemic crustacean (a term designating a species found only in a delimited geographical area of the groundwater in the greater central-western France).
During the subsequent field campaign, between 2013 and 2015, the associated underground aquatic fauna was also systematically inventoried at 129 sites covering the 4 departments of the former Poitou-Charentes region.
Detailed identification of the collected specimens (morphology and genetics) revealed previously unsuspected biodiversity: about thirty identified taxa, with many “first mentions,” and several probable new species for science.
Considering the importance of the results obtained for French stygofauna, which remains poorly known, or even ignored, particularly in the Grand-Ouest, France Nature Environnement Nouvelle-Aquitaine and SEPANSO Aquitaine decided to extend the research to the two former Limousin and Aquitaine regions.
A study program, titled “Inventory of Underground Aquatic Fauna and Environmental Quality in Nouvelle-Aquitaine,” was therefore initiated with the following objectives:
- to establish an inventory of regional stygofauna, an inventory conducted in continuity with the one previously carried out in Poitou-Charentes to provide comparable data across the entire Nouvelle-Aquitaine territory,
- and to understand the relationship between the presence of this fauna in its natural habitats and the quality of groundwater.
The Ongoing Study Program
The primary objective of the program is to create an inventory of regional underground aquatic fauna.
The Goal
Based on the study conducted in Poitou-Charentes, the inventory extended to Nouvelle-Aquitaine should make it possible to double, or even triple, the number of known species, with “first mentions” for most of the departments concerned, and possibly new species for science. It will also allow for a more precise definition of the geographical and/or ecological limits for already known species.
The program also aims to understand the relationship between the presence of this fauna in its natural habitats and the quality of groundwater, to consider the development of bio-indication tools. Sensitive to water quality and temperature variations, stygofauna is indeed an excellent indicator of the quality and functioning of underground hydrosystems, natural environments very sensitive to human activities and surface pollution.
With nearly 400 recorded taxa, French stygobian fauna is considered one of the richest in Europe, even though certain geographical areas, including the Grand-Ouest, are still under-prospected.
As a project for acquiring knowledge related to biodiversity and the quality of underground aquatic environments, the program is part of various existing policies and programs at several levels (Green and Blue Infrastructure, Regional Planning, Sustainable Development and Territorial Equality Scheme, Regional Biodiversity Strategy, Neo Terra roadmap – ambitions 8 and 9, Re-Sources regional program).
This program and its potential follow-ups in terms of water resource protection and aquatic environment preservation will help address some of the challenges, orientations, and/or measures of the Adour-Garonne Water Development and Management Master Plan (2022-2027).
Provisional Timeline & Work Organization
Given the experience gained during the study conducted in Poitou-Charentes, the project was divided into two phases:
- Phase 1, carried out from September 2019 to April 2020, identified the potential for habitats and species in the new study area and selected priority sites of interest for investigation in each department.
- An operational Phase 2, which began in April 2021 and is expected to continue until 2023, involves conducting field campaigns (sampling and physico-chemical measurements at sites pre-selected in Phase 1), species identification by taxonomic experts, analysis of all collected data, and dissemination and valorization of acquired knowledge.
Phase 1
In Phase 1, FNE Nouvelle-Aquitaine was the project leader, which was the subject of a project management delegation agreement between FNE Nouvelle-Aquitaine and SEPANSO Aquitaine on June 14, 2018.
Phase 2
In Phase 2, SEPANSO Aquitaine leads the program and ensures its implementation, with the support of FNE Nouvelle-Aquitaine.
Since the beginning of Phase 1, the two project managers with complementary skills working on this study program are Thierry ALEZINE (hydrogeologist) and François LEFEBVRE (biologist and ecologist of underground environments), who previously led the study in Poitou-Charentes. Since September 2, 2024, Céline JOUANIN (hydrobiologist and biostatistician) has joined the team to analyze the collected data.
Program Governance and Funding
Governance
To successfully implement this program, a Steering Committee (CoPil) was established at the beginning of Phase 1.
It was formed with representatives of funding organizations and various technical and scientific experts (hydrogeologists, biospeleologists, taxonomists), allowing it to have a decision-making role.
This CoPil, whose composition was chosen to enable it to have a decision-making role, consists of scientific and technical experts and financial partners.
Funding
Since the beginning of Phase 1, this program has been funded by the Nouvelle-Aquitaine Regional Council, the Gironde Departmental Council, DREAL Nouvelle-Aquitaine, and the Adour-Garonne Water Agency.
In Phase 2, the program also benefited from co-financing from the European Union and the Nouvelle-Aquitaine Region, and funding from the Léa Nature 1% for the Planet Foundation.
Awareness and Valorization
The data collected within the framework of the study program are of general interest, and the expected improvement in the state of knowledge on regional stygofauna must be shared with the public as well as with water, natural heritage, and environmental stakeholders in the Nouvelle-Aquitaine Region.
A societal component of environmental education will thus be integrated into the program, with, among other objectives, training and awareness sessions (elected officials, biodiversity stakeholders, general public), followed by a phase of results valorization in the form of press articles and scientific publications.
Throughout the operational phase of the program, information and awareness work will be carried out in collaboration with numerous stakeholders:
- nature and environmental protection associations (APNE) as well as other associations affiliated with FNE Nouvelle-Aquitaine, notably via SEPANSO Aquitaine and FNE Limousin;
- the departments via their websites;
- the departmental speleological committees and the Biospeleology commission of the French Speleological Federation;
- the French Geological Survey (BRGM), via the website of the Groundwater Management Information Systems (SIGES) Nouvelle-Aquitaine;
- the Nouvelle-Aquitaine Natural Spaces Conservatory;
- the Nouvelle-Aquitaine Regional Biodiversity Agency.
Finally, the naturalist knowledge obtained through this program will also be utilized by secondary education establishments of the National Education and Agricultural Education systems.
Valorization of Collected Data and Program Results
Online archiving of collected data will be carried out notably through DREAL Nouvelle-Aquitaine via the Nouvelle-Aquitaine Wildlife Observatory and the Nouvelle-Aquitaine Regional Biodiversity Agency via the Regional Biodiversity Observatory.
The knowledge obtained through the program will be valorized through various tools:
- inventory notes, articles in newsletters and on the websites of speleological and naturalist associations;
- scientific publications, written in collaboration with associated specialists and researchers;
- participation and presentations at conferences.
Site Selection
During Phase 1 of the program, an examination of the potential of the Nouvelle-Aquitaine region in terms of habitats for stygofauna was carried out, based on the types of existing aquifers.
Following this preparatory work, the following habitats were selected:
- caves, cavities, underground galleries where groundwater circulation exists;
- underground quarries where the water table outcrops, or mine galleries partially submerged or flooded;
- outlets of free-flowing aquifers, springs, and shallow catchments (wells, boreholes, piezometers);
- sites in hyporheic environments (underflow of watercourses).
These are mainly sensitive natural sites subject to protection measures (e.g., sites for bats or freshwater pearl mussels), mining sites, as well as drinking water supply (AEP) catchment sites, whose location must remain confidential.
How were the sites chosen?
The selection of sites to be prospected followed a sampling strategy defined to:
- diversify the sites to be prospected by investigating all environments likely to host stygofauna;
- revisit a certain number of sites already known to host stygofauna (up to 1/3 if possible), and thus ensure long-term monitoring of this historical data;
- maintain a certain proportionality between departmental areas and the number of prospected sites, and to have homogeneous geographical coverage for each department;
- preserve the methodology used (i.e., multi-stratified sampling) during the study carried out in Poitou-Charentes and maintain an equivalent prospecting effort.
