MEPS 522:97-114 (2015)  -  DOI: https://doi.org/10.3354/meps11151

Effects of macroalgal accumulations on the variability in zoobenthos of high-energy macrotidal sandy beaches

Nolwenn Quillien1,2,3,*, Marie C. Nordström2, Olivier Gauthier1,3, Erik Bonsdorff2, Yves-Marie Paulet1,3, Jacques Grall3

1Laboratoire des Sciences de l’Environnement Marin, UMR 6539, Institut Universitaire Européen de la Mer, Plouzané, France
2Åbo Akademi University, Department of Biosciences, Environmental and Marine Biology, Turku, Finland
3Observatoire des Sciences de la mer et de l’univers, UMS 3113, Institut Universitaire Européen de la Mer, Plouzané, France
*Corresponding author:

ABSTRACT: Sandy beaches, forming the most widespread coastal habitat in the world, are threatened by the effects of increasing anthropogenic pressure in the context of global change, including the increased occurrence of green tides composed of free-living Ulva spp. Sandy beaches are also highly dynamic ecosystems that support numerous essential ecological functions and contain a distinctive biodiversity, but their precise functioning and natural variability (i.e. the disentangling of biological and physical influences) remain under-studied. Our study aimed at determining the effects of space, time, and environmental variables on the natural variability of macrofaunal community structure and at specifically determining the effects of macroalgal accumulations on the observed variability. We followed a high-resolution field sampling design in space and time (261 samples) at non-vegetated and at partially and fully green-tide-impacted macrotidal sandy beaches. We used novel statistical approaches (distance-based Moran’s eigenvector maps [dbMEMs] and variation partitioning) to analyse our results. The macrofaunal community structure of the non-vegetated sandy beach was variable in space and time at small scales, and physical environmental variables significantly explained these variations. Our study also highlighted a decrease in this variability along a gradient of increasing coverage of stranded Ulva spp. and the increasing importance of biological variables in explaining ecological variability. Compared to a state with no Ulva, a large and homogeneous coverage of Ulva along a sandy beach shore induced a significant decrease of overall β-diversity. However, macrofaunal responses to macroalgal accumulation were less pronounced than what has been previously shown in micro-tidal and sheltered systems, likely due to the dynamic and unstable nature of high-energy macrotidal sandy shores.


KEY WORDS: Macrotidal sandy beach · Macrofauna · Green tides · Space-time analysis · β-diversity


Full text in pdf format
Supplementary material 
Cite this article as: Quillien N, Nordström MC, Gauthier O, Bonsdorff E, Paulet YM, Grall J (2015) Effects of macroalgal accumulations on the variability in zoobenthos of high-energy macrotidal sandy beaches. Mar Ecol Prog Ser 522:97-114. https://doi.org/10.3354/meps11151

Export citation
Mail this link - Contents Mailing Lists - RSS
- -