COS 54-1 - Long-term macrobenthic Ecological Trajectory Analysis reveals general stability over a large spatial scale

Tuesday, August 16, 2022

8:00 AM – 8:15 AM EDT

Location: 518A

Presenting Author(s)

CT

Chirine Toumi

PhD candidate
LEMAR, Univ Brest, CNRS, IRD, Ifremer, 29280 Plouzané, France, Bretagne, France

Coauthor(s)

MD

Miquel De Cáceres

CREAF, Campus de Bellaterra, Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Barcelona, 08193, Spain, Spain
JG

Jacques Grall

LEMAR, Univ Brest, CNRS, IRD, Ifremer, 29280 Plouzané, France - OSU IUEM, Univ Brest, CNRS, IRD, 29280 Plouzané, France
Plouzané, Bretagne, France
ET

Eric Thiebaut

Sorbonne Université, CNRS, Station Biologique de Roscoff, UMR7144, Adaptation et Diversité en Milieu Marin, Place Georges Teissier, CS90074, 29688, Roscoff Cedex, France, France
AB

Aurelien Boyé

Ifremer, Centre de Bretagne, DYNECO, Laboratory of Coastal Benthic Ecology, Plouzané, France, France
CB

Caroline Broudin

CNRS, Station Biologique de Roscoff, FR 2424, Sorbonne Université, Roscoff, France, France
CH

Celine Houbin

CNRS, Station Biologique de Roscoff, FR 2424, Sorbonne Université, Roscoff, France, France
MM

Marion Maguer

OSU IUEM, Univ Brest, CNRS, IRD, 29280 Plouzané, France
Plouzané, France
VL

Vincent Le Garrec

OSU IUEM, Univ Brest, CNRS, IRD, 29280 Plouzané, France
Plouzané, Bretagne, France
OG

Olivier Gauthier

LEMAR, Univ Brest, CNRS, IRD, Ifremer, 29280 Plouzané, France - OSU IUEM, Univ Brest, CNRS, IRD, 29280 Plouzané, France
Plouzané, Bretagne, France

Background/Question/Methods

Long-term monitoring programs are fundamental to detect changes in ecosystem health and understand ecological processes. In the current context of global warming and increasing anthropogenic threats on marine ecosystems, understanding the dynamic and response of communities becomes essential. Here we use data collected over 14 years in the REBENT benthic coastal invertebrates monitoring program, at 26 sites at a regional scale in the North-East Atlantic, covering a total of 979 taxa. Four distinct habitats are studied: two of them associated with foundation species, eelgrass, and maerl, respectively in the intertidal and subtidal zones while the two others were bare sediments in the same tidal zones. We use Ecological Trajectory Analysis (ETA), a statistical approach that allows for quantitative measures and comparisons of temporal trajectories of ecosystems. We compare community trajectories to trajectories simulated under a non-directional null model as well as to environmental trajectories, in order to better understand the dynamics of the communities, their potential drivers, and the role of the studied habitats in these dynamics.

Results/Conclusions

Despite strong differences in the community compositions between sites and habitats, the communities from the four habitats follow a non-directional dynamic during the 14 monitored years, which suggests stability at the regional scale. However, the shape, size, and direction of the trajectories of the communities were more similar within than among habitats, suggesting the influence of the nature of the habitat on the community dynamics. The environmental and community trajectories in the intertidal bare habitat both show a higher variability during the first five years of the monitoring. Moreover, the comparison between environmental trajectories and community trajectories confirms the role of biogenic habitats in buffering the effects of environmental conditions and a higher sensitivity of intertidal community dynamics to environmental variations. Despite the fact that mechanisms and ecological processes are not necessarily the same across habitats, our study demonstrates the long-term stability of macrobenthic communities over the studied area. These results differ from what might be expected in a global change context. We hypothesize that including numerous monitoring sites across different habitats might evidence an overall stability of coastal ecosystems over large spatial scales, although increasing pressures might lead to a large amount of inherent and local heterogeneity.