Advances in sandy beach research - Local and global perspectives

Urbanization effects on sandy beach macrofauna along an estuarine gradient

Cumulative stressors impact macrofauna differentially according to sandy beach type: A meta-analysis.

This paper applies and extends the concept of Littoral Active Zone (LAZ) of sandy beaches as a relevant dimension to observe and manage this socio ecological system. The LAZ is a dynamic zone where exchanges across land and sea occur, and this concept was initially proposed on a geomorphological background only. However, to achieve full relevance and timely address management choices tied to the functioning of soft sediment shores, it became appropriate to extend its consideration to both the ecological and social templates co-existing on the same physical unit. Current paradigms around the concept of LAZ were used as a background to organize information from different disciplines and extend the concept to different soft sediment shores (mostly sandy beaches and salt marshes), towards a global, integrated relevance of the concept. As a test for this approach, we 1) struabctured information on the biophysical and social templates around the concept of LAZ, 2) extended it to salt marshes and 3) applied it to the case of the Breton coast for a practical test on information organization. Such an exercise highlighted key characteristics of the LAZ using a multidisciplinary approach, but also gaps to be filled when targeting research, perception, communication, sustainable use and management of the LAZ as a functional unit.

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The extended concept of littoral active zone considering soft sediment shores as social-ecological systems, and an application to Brittany (North-Western France)

Coupling beach ecology and macroplastics litter studies: Current trends and the way ahead.

Sandy beaches are severely under-represented in the literature on climate-change ecology, yet different lines of evidence suggest that the macrofauna inhabiting these narrow and dynamic environments located at the land-sea interface is being reorganized under the influence of this large scale and long-lasting stressor. This is reflected in macrofaunal sensitivity to increasing sea surface temperature, sea-level rise, extreme events and erosion of the narrow physical habitat. However, evidence of behavioral responses by sandy beach macrofauna that are consistent with expectations under climate change is scarce and fragmentary. In this paper, specific hypotheses are formulated for how behavioral adaptations in sandy beach macrofauna are predicted to respond to climate change impacts. Firstly, a conceptual framework and an overview of macrofauna behavioral adaptation features are provided. Secondly, the effects of main climate change drivers on sandy beaches are summarized. Thirdly, a conceptual framework is developed giving behavioral adaptations of sandy beach macrofauna under climate change pressure. The degree to which observations on behavioral adaptations of beach animals conform to expectations under specific climate change drivers (sea level rise, sea surface temperature, winds and storminess, rainfall, acidification and eutrophication) is explored. Taking into account the empirical evidence and the theoretical framework detailed in the paper, emergent hypotheses/predictions are proposed. Climate change drivers are expected to impact habitat features and consequently the behavioral expression of macrofauna as active responses to habitat changes. Behavioral adaptations are expected to be impaired, more variable or disrupted, thus decreasing fitness, causing local population extirpations and potentially triggering a range of cascading effects of ecological change in the beach ecosystem. Biodiversity loss will be the outcome of the negative pressures driven by climate change. The specificity of sandy beaches as narrow ecotones between sea and land may be lost under climate change pressure, adversely affecting fine-tuned macrofaunal adaptations and therefore ecosystem functioning. Strictly adapted endemic sandy beach fauna will be especially subjected to local extirpations, while species with a large reaction norm (i.e. phenotypic and behavioral plasticity) may face changes by dispersal and exploitation of new niches. Under climate change impacts, biodiversity loss is predicted, which would hamper beach ecosystem resilience. The limits to which sandy beach macrofauna responds and can behaviorally adapt to environmental change are worthy of exploration, in view of the increasing influence of the long-lasting climate driven stressors threatening these ecosystems at risk.

Emilia Innocenti Degli

Papers

Behavioral adaptations of sandy beach macrofauna in face of climate change impacts: A conceptual framework

Arthropodofauna richness and abundance across beach-dune systems with contrasting morphodynamics