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International audience

Le projet Micropolit a eu pour objectif de décrire et de suivre l'évolution de la qualité du milieu littoral sud aquitain avec une approche pluri-disciplinaire, spatiotemporelle et en considérant plusieurs compartiments (eau/sédiment/biote). Ce document a vocation de synthétiser pour chaque biote les protocoles de collecte, mesures, préparation et stockage des échantillons biologiques en vue de leurs analyses chimiques mis en oeuvre dans le cadre du projet. Chaque fiche est indépendante, pour de plus amples détails, se reporter aux publications ou aux autres livrables du projet. Echantillons biologiques considérés : I. Espèces commerciales (poissons et crevettes avec parasites dans le cas du merlu) II. Zooplancton III. Goéland leucophée IV. Taxons biodiversité benthique V. Microorganismes procaryotes

International audience

The rocky Basque coast presents an interest both in terms of biogeography and its patrimonial situation, alongside its habitats, fauna and flora. The aim of the BIGORNO project (Intertidal Biodiversity of the south of the Bay of Biscay and Observation for New research and Monitoring for decision support), financed by the Agency of Marine Protected Areas (AAMP) and the Departmental Council (CD 64), is to respond to significant deficiencies on biocenosis in the southern marine subregion “Bay of Biscay”. Investigations carried out in the WFD, since 2008, constitute an important basis of work for integration of fauna. Field studies undertaken since 2015 consisting of a sampling design suited to the substrates heterogeneity and the presence of microhabitats were established on an intertidal area specifically on a "Boulder fields" habitat. Assessment was undertaken by sampling quadrats of 0.1 m² drawn randomly from a spatially stratified sampling plan. Our study aims for a better understanding of stratification of this habitat and allowed us to highligh tindicator taxa of the "Boulder fields" habitat. Functions included in the package indicspecies (CRAN) were used to conduct indicator species analysis and to assess the significance of the relationship between taxa or taxa combinations and the habitat. It is therefore possible to describe some species or species groups which are specific to boulder fields through the assessment of their functional traits and local biodiversity. These various analyses allow for a sustainable way of monitoring the Basque intertidal rocky shore.

Le projet Micropolit a eu pour objectif de décrire et de suivre l'évolution de la qualité du milieu littoral sud aquitain avec une approche pluri-disciplinaire, spatiotemporelle et en considérant plusieurs compartiments (eau/sédiment/biote). Ce document a vocation de synthétiser pour chaque biote les sites concernés, les molécules recherchées et les principaux résultats obtenus. Chaque fiche est indépendante. Pour de plus amples détails, se reporter aux publications ou aux autres livrables (dont celui sur les protocoles de collecte, mesures, préparation et stockage des échantillons biologiques en vue de leurs analyses chimiques). Un bilan synthétique des productions pour ce volet biote est présenté en fin de document. Échantillons biologiques considérés : I. Espèces commerciales (poissons et crevettes avec parasites dans le cas du merlu) II. Espèce amphihaline (anguille européenne) III. Zooplancton IV. Goéland leucophée V. Taxons biodiversité benthique VI. Microorganismes procaryotes

Biodiversity conservation and response of benthic communities to pressures, related to global change and human activities, are a research priority. They also constitute a useful indicator to define the environmental status of the Marine Strategy Framework Directive as part of the European Water Framework Directive (WFD). The biogeographic features of the Aquitanian coast (in terms of rocky substrate communities) induce the interest to have a monitoring and research site. Indeed, it includes the habitat characteristics as well as fauna and flora (the Habitats Directive). The aim of the BIGORNO project is to implement new tools to assess the rocky biocenosis in the southern marine subregion of the Bay of Biscay by integrating fauna communities assessment (flora communities already monitored in WFD). This provides further information about the intertidal biodiversity and the spatial distribution of benthic communities. A standardized procedure for collecting information on benthic communities provides relevant indicators of intertidal habitat. Global environmental change (including climate evolution) should be considered while entering these indicators in European framework in order to compare results over longer periods. Using a spatially stratified random sampling plan, the mobile fauna (true abundance), fixed fauna and macroalgae (percentage cover) were measured in quadrats of 0.1 m² spread both on upper and lower mediolittoral zones. The analysis highlight dependent faunistic and floristic structuration according to microhabitats which confirms the need of a such stratification. Species/taxa or species associations were also identified as indicators of microhabitats. These various analysis improve knowledge for monitoring the Basque intertidal rocky shore in a sustainable way. Finally, within the Marine Strategy Framework Directive, these results allow to take into account biogeographic specificities to harmonize protocol metrics at the scale of the sub-area Bay of Biscay.