Alexandre Mercière

Ecole Pratique des Hautes Etudes | EPHE · CRIOBE - Centre de Recherche Insulaire et Observatoire de l’Environnement

While the fire coral Millepora platyphylla is an important component of Indo-Pacific reefs, where it thrives in a wide range of environments, the ecological and biological processes driving its distribution and population structure are not well understood. Here, we quantified this species’ population structure in five habitats with contrasting hydr...

Coastal nursery habitats are essential for the renewal of adult fish populations.We quantified the availability of a coastal nursery habitat (shallowheterogeneous rocky bottoms) and the spatial variability of its juvenile fish populations along 250 km of the Catalan coastline (France and Spain). Nurserieswere present in 27% of the coastline, but on...

The brown meagre (Sciaena umbra) is an endangered species, which requires specific protection measures to ensure its conservation. These measures need to be informed by high-quality scientific knowledge on their space use patterns. Here, we used acoustic telemetry to assess its seasonal movement patterns and habitat use within a marine protected ar...

Consumers play an important role in biogeochemical cycles through the consumption and release of essential elements such as carbon (C), nitrogen (N), and phosphorus (P). Indeed, a large proportion of consumed elements are released into the environment in inorganic (i.e. excretion) or organic form (i.e. egestion). On coral reefs, fishes represent th...

Corals share an intimate relationship with photosynthetic dinoflagellates that contribute to the biology of the emerging metaorganism. While many coral-algal associations exhibit high host fidelity, the extent of this specificity under environmental change remains to be fully understood and is a prerequisite to forecasting the adaptive potential of...

Organismal metabolic rates (MRs) are the basis of energy and nutrient fluxes through ecosystems. In the marine realm, fishes are some of the most prominent consumers. However, their metabolic demand in the wild (field MR [FMR]) is poorly documented, because it is challenging to measure directly. Here, we introduce a novel approach to estimating the...

Human impact increasingly alters global ecosystems, often reducing biodiversity and disrupting the provision of essential ecosystem services to humanity. Therefore, preserving ecosystem functioning is a critical challenge of the twenty-first century. Coral reefs are declining worldwide due to the pervasive effects of climate change and intensive fi...

Coral reefs provide a range of important services to humanity, which are underpinned by community-level ecological processes such as coral calcification. Estimating these processes relies on our knowledge of individual physiological rates and species-specific abundances in the field. For colonial animals such as reef-building corals, abundance is f...

Antipatharians, also called black corals, are present in almost all oceans of the world, until extreme depths. In several regions, they aggregate in higher densities to form black coral beds that support diverse animal communities and create biodiversity hotspots. These recently discovered ecosystems are currently threatened by fishing activities a...

Coral microbiomes are critical to holobiont functioning, but much remains to be understood about how prevailing environment and host genotype affect microbial communities in ecosystems. Resembling human identical twin studies, we examined bacterial community differences of naturally occurring fire coral clones within and between contrasting reef ha...

• Trait-based approaches are increasingly used to study species assemblages and understand ecosystem functioning. The strength of these approaches lies in the appropriate choice of functional traits that relate to the functions of interest. However, trait–function relationships are often supported by weak empirical evidence. • Processes related to...

The spatio-temporal variability of fish distribution is important to better manage and protect the populations of endangered species. In this sense, the vertical movements of a vulnerable and protected species, Sciaena umbra, were assessed in a marine protected area (the Réserve Naturelle Marine de Cerbère-Banyuls, south of France) to study the var...

Sea‐level rise is predicted to cause major damage to tropical coastlines. While coral reefs can act as natural barriers for ocean waves, their protection hinges on the ability of scleractinian corals to produce enough calcium carbonate (CaCO3) to keep up with rising sea levels. As a consequence of intensifying disturbances, coral communities are ch...

Coral microbiomes are critical to holobiont health and functioning, but the stability of host-microbial interactions is fragile, easily shifting from eubiosis to dysbiosis. The heat-induced breakdown of the symbiosis between the host and its dinoflagellate algae (that is, "bleaching"), is one of the most devastating outcomes for reef ecosystems. Ye...

Somatic growth is a critical biological trait for organismal, population, and ecosystem-level processes. Due to its direct link with energetic demands, growth also represents an important parameter to estimate energy and nutrient fluxes. For marine fishes, growth rate information is most frequently derived from sagittal otoliths, and most of the av...

Energy flow and nutrient cycling dictate the functional role of organisms in ecosystems. Fishes are key vectors of carbon (C), nitrogen (N) and phosphorus (P) in aquatic systems, and the quantification of elemental fluxes is often achieved by coupling bioenergetics and stoichiometry. While nutrient limitation has been accounted for in several stoic...

Dispersal is a critical process for the persistence and productivity of marine populations. For many reef species, there is increasing evidence that local demography and self‐recruitment have major consequences on their genetic diversity and adaptation to environmental change. Yet empirical data of dispersal patterns in reef‐building species remain...

Coral reefs are one of the most productive and diverse ecosystems on Earth. However, climate warming is occurring at an unprecedented rate and has negatively affected coral reefs worldwide. Evaluating the life history of reef-building species carries important implications for coral reef conservation. This chapter examines the taxonomy, biogeograph...

Man‐made infrastructures have become ubiquitous components of coastal landscapes, leading to habitat modification that affects the abundance and diversity of marine organisms. Marine coastal fish have a complex life cycle requiring different essential habitats. One of these habitats is known as a nursery, a place where juveniles can settle in large...

Dispersal is a critical process for the persistence and productivity of marine populations. For many reef species, there is increasing evidence that local demography and self-recruitment have major consequences on their genetic diversity and adaptation to environmental change. Yet empirical data of dispersal patterns in reef-building species remain...

Along the littoral, a growing number of anthropogenic structures have caused substantial habitat destruction. Despite their detrimental impact, these constructions could play a role in the functioning of coastal ecosystems. The objective of this work was to assess the distribution of juvenile coastal fish along a seascape composed of various natura...

The concentration of human activities along the shoreline induces high levels of pressure, notably seascape urbanization caused by the proliferation of coastal and marine infrastructures such as ports, harbors, marinas and coastal defense structures. Because they are localized in sheltered and shallow coastal areas, these infrastructures inevitably...

Index describing the spatial distribution, recruitment and morphology for Millepora platyphylla across the five surveyed habitats. (XLSX)

Average percentages of adult colonies for Millepora platyphylla with encrusting, sheet tree and massive morphology across surveyed habitats. (XLSX)

Locations of each transect surveyed in the five habitats. (XLSX)