Using the RESOMAR Benthic Macrofauna Database to assess spatio-temporal dynamics of coastal benthic assemblages and Environmental Status in relation with descriptor 1 (Biodiversity) of the Marine Strategy Framework Directive (MSFD) – BenthoVal

Historical benthic macrofauna community data is analysed with the Numerical Ecology toolbox in order to describe natural spatial and temporal patterns and dynamic of diversity. We are also developing a new biotic index to evaluate EcoQ and are testing its relative performance with datasets relating to various types of anthropogenic pressure gradients (physical, chemial, organic …).

The project has mobilised other European researchers that have contributed ideas and datasets describing both macrofauna and pressure gradients to the exercise. We have established a portrait of macrofaunal benthique diversity in Metropolitan over the time scope of the database. We have mapped the present EcoQ of the Gulf of Lion and established it global stability between 1998 and 2010.

Current results indicate that the project will contribute significantly to the optimisation of EcoQ evaluation and long-term observation protocols, notably by providing better tools and a better understanding of natural patterns.

We have presented our ideas and results in numerous national and international meeting and workshops. On these occasions we communicated on the spatio-temporal diversity patterns and dynamics, a critical review of currently available biotic indices, the new index developed within the project, as well as the first evaluations of its relative performance. This work constitutes the basis for research articles currently in preparation.

The ultimate goal of the proposal is to assess the current Ecological Quality (EcoQ) of coastal and littoral benthic habitats in Metropolitan France. It thus addresses fundamental scientific questions that will find immediate as well as long-term use for public action. Its specific objectives are to validate, develop and apply methods that rely on biological community data (composition, structure and function) and sediment imagery to characterise the ecological state of marine habitats.

The RÉseau des Stations et Observatoires MARins (RESOMAR, INSU, CNRS) aims to federate coastal marine biology research at the national level. In 2007 it undertook the task of implementing databases of current and historical datasets relating to benthic and pelagic compartments of Metropolitan France costal and littoral ecosystems. RESOMAR Benthic Macrofauna DataBase (BMDB) presently holds 106 datasets containing macrofaunal abundances and biomass for a total of 9,957 sampling stations. It spans a 50-year time period (1961 to present) and covers France’s entire metropolitan coastline. The BMDB notably includes most datasets acquired within the WFD and the Habitats Directive in Metropolitan France. The BMDB is to be used to answer difficult scientific questions at spatial scales beyond that of the single marine station. It is thus particularly well adapted to tackle questions raised by the application of the WFD, the Habitats Directive and the MSFD.

The spatiotemporal scope of the database will first allow an analysis of natural variation patterns in marine benthic communities. This will, allow the identification of characteristic spatial and temporal scales of variations and their consideration in subsequent analysis. Indeed, variability attributable to seasonal, other cyclic phenomenon, or changes in meteorological conditions, must be taken into account when assessing EcoQ : these parameters are, a priori, not linked to disturbance gradients and should not influence EcoQ evaluation.

The Biotic Indices (BI) currently used within the WFD will be compared among themselves and others in order to evaluate their relative performance and how they relate to each other. New indices, based on the concept of multidimensional deviation in community structure from a reference condition, will be developed and compared to existing ones. The innovative method of Sediment Profile Imagery will also be used to obtain and evaluate independent estimates of EcoQ. Considering the spatial scope targeted by the MSFD and the time and resource consuming aspect of actual faunal community sampling, it appears necessary to develop and validate cost-effective complementary methods.

This research will tackle the relationship between various types of disturbances and EcoQ assessment. Indeed, anthropic pressure data should be related to variation in Macrofaunal benthic community structure. Ideally, disturbance data should be of a quantitative nature, but semi-quantitative can be accommodated in statistical models. Although past research has mainly focused on disturbances related to organic enrichment, the current project will focus on multiple types of disturbances (e.g. trawling, water treatment stations, aggregate extraction, dredging, etc.) that can have different impact on community structure. In whole, the joint analysis of disturbance and community data will allow to confirm whether a BI can adequately describe the EcoQ of habitats submitted to different anthropic pressures.