Observation series

Monitoring of benthic habitats

The macrofauna and macroflora communities and the biodiversity associated with the four target habitats (soft intertidal, intertidal macroalgae, eelgrass beds with Zostera marina, maerl) are monitored at 58 stations around Brittany. In the Brest-Iroise Workshop Area (ZABrI), the observation pressure is more intense on the maerl and the meadows.

Within the coastal research infrastructure (IR-ILICO), the harmonisation of sampling and determination techniques has made it possible to improve the quality of the data produced (annual intercalibration seminars). The IUEM plays a central role in this process as it actively participated in the organisation of the first seminar dedicated to the issue, in 2010. From a societal point of view, the data are used to comply with the Water Framework Directive (WFD) and the Marine Strategy Framework Directive (MSFD). The IUEM Marine Observatory team is heavily involved in the project to label the benthic series BenthOBS at the national level. It is also involved in the development of indicators dedicated to the DCSMM and in particular in the D1-biodiversity and D2-non-native species components.

Partners

The sites

Long-term monitoring of benthic habitats carried out at the IUEM is implemented on the whole of Brittany’s coasts, from Mont-Saint-Michel Bay to Vilaine Bay. They are carried out on four emblematic habitats of the Brittany coasts: rocky foreshores, sandy foreshores (beaches), eelgrass beds and maerl beds.
The Brest harbour and the Iroise Sea are focal points where the observation pressure is increased, both spatially, with a high concentration of observation stations, and temporally, with a higher frequency of observation.

Follow-ups

Monitoring is carried out once a year at each site, at the end of spring. In the Brest-Sea of Iroise area, this monitoring is doubled in the autumn.

Parameters recorded for each habitat :

Intertidal rocky areas :

species of macroalgae present and their abundance

Sandy foreshore :

species of benthic invertebrates present and their abundance,
sediment grain size,
organic matter content of the sediment

Intertidal eelgrass beds :

species of benthic invertebrates present and their abundance,
sediment grain size,
organic matter content of the sediment,
density, length, biomass of eelgrass plants

Maerl benches :

species of benthic invertebrates present and their abundance,
sediment grain size,
organic matter content of the sediment,
maerl vitality (rate of recovery in living maerl).

Access to data

The data are stored in the Quadrige coastal monitoring database and are available from the Surval portal.

In addition, all the data is stored in the MARBEN database of the IUEM and can be accessed on request from Marion Maguer and Jacques Grall (see “contact” section below).

Access to the Surval portal

Publications

The data from Benthobs monitoring is widely used by the scientific community and has been the subject of numerous scientific publications.

Download the list of publications

Benthic habitats

In pictures

(C) ErwnAMICE | CNRS
Sampling the Roscanvel herbarium
(C) ErwnAMICE | CNRS
Analysis of marine benthic macrofauna samples in the laboratory
(C) Nolwenn Quillien
Mission Maerl REBENT 2012 – Benne Smith McIntyre au soleil levant
(C) Vincent Le Garrec | UBO
Fabulina fabula (Gmelin, 1791)
(C) Vincent Le Garrec | UBO
Papillicardium papillosum (Poli, 1791)
(C) Vincent Le Garrec | UBO
Onuphis eremita (Audouin & Milne Edwards, 1833)
(C) Vincent Le Garrec | UBO
Microalgae on a maerl thallus (microscopie électronique à balayage – MEB)