Mehdi Adjeroud

Mehdi Adjeroud
Institute of Research for Development | IRD · 227 - Biocomplexity of Coral Reefs Ecosystems in the Indo-Pacific (CoRéUs 2)

PhD

About

157
Publications
43,416
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
3,780
Citations
Introduction
Skills and Expertise
Additional affiliations
December 2009 - present
Institute of Research for Development
Position
  • Senior Researcher
January 2000 - December 2009
Ecole Pratique des Hautes Etudes
Position
  • Professor (Associate)

Publications

Publications (157)
Article
Full-text available
Amidst global environmental changes, predicting species' responses to future environments is a critical challenge for preserving biodiversity and associated human benefits. We explored the original idea that coral competitive performances, the ability of corals to preempt ecological space on the reef through territorial warfare, serve as indicators...
Article
Full-text available
Recurring outbreaks of crown-of-thorns starfish (COTS) severely damage healthy corals, especially in the Western Pacific Ocean. To obtain a better understanding of population genetics of COTS and historical colonization across the Pacific Ocean, complete mitochondrial genomes were sequenced from 243 individuals collected in 11 reef regions. Our res...
Article
Full-text available
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...
Article
Full-text available
Maintaining key functions of coral reefs is vital for the persistence of these ecosystems as well as for securing the goods and services that they provide in the Anthropocene. Underwater photogrammetry by Structure from Motion (SfM) allows the quantification of novel habitat descriptors that may be particularly relevant in assessing key reefscape t...
Article
Full-text available
Ecosystems worldwide are suffering from climate change. Coral reef ecosystems are globally threatened by increasing sea surface temperatures. However, gene expression plasticity provides the potential for organisms to respond rapidly and effectively to environmental changes, and would be favored in variable environments. In this study, we investiga...
Article
Outbreaks of crown-of-thorns starfish Acanthaster spp. (COTS) are among the most severe local threats to Indo-Pacific coral reefs. Despite intensive research, the factors triggering outbreaks remain unclear, though could involve enhanced COTS larval fitness due to ocean warming and acidification. Nevertheless, the effect of these combined stressors...
Preprint
Full-text available
Amidst global environmental changes, predicting species responses to future environments is a critical challenge for preserving biodiversity and associated human benefits. We explored the original idea that coral competitive performances, the ability of corals to preempt ecological space on the reef through territorial warfare, serve as indicators...
Article
Full-text available
The Great Reef of Toliara, on the southwestern coast of Madagascar, has been documented as harbouring flourishing reef communities in the 1960s, but has since been affected by various threats, causing a coral decline last reported in 2008. In 2017, we examined the spatial heterogeneity in coral community structure in the region of Toliara. Coral as...
Preprint
Scleractinian corals are of great ecological interest as ecosystem engineer species. Accordingly, there is a wealth of studies on their adaptive abilities facing climate change. Such studies should rely on precise species and population delimitation. Nevertheless species delimitation in corals can be hindered by the lack of adequate genetic markers...
Article
Full-text available
The choice of ecological monitoring methods and descriptors determines the effectiveness of a program designed to assess the state of coral reef ecosystems. Here, we comparer the relative performance of the traditional Line Intercept Transect (LIT) method with three methods derived from underwater photogrammetry: LIT on orthomosaics, photoquadrats...
Article
Full-text available
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...
Article
Full-text available
Building trust in science and evidence-based decision-making depends heavily on the credibility of studies and their findings. Researchers employ many different study designs that vary in their risk of bias to evaluate the true effect of interventions or impacts. Here, we empirically quantify, on a large scale, the prevalence of different study des...
Article
Full-text available
Understanding colonization of new habitats and ecological successions is key to ecosystem conservation. However, studies on primary successions are scarce for reef-building corals, due to the rarity of newly formed substratum and the long-term monitoring efforts required for their long life cycle and slow growth rate. We analysed data describing th...
Article
Full-text available
Structural complexity plays a key role in the functioning of coral reef ecosystems. Reef-building corals are major contributors to this complexity, providing shelter and food for numerous invertebrates and fish species. Both structural complexity and shelter capacity of reefscapes are determined by several components such as spurs and grooves, slop...
Article
Outbreaks of the coral-eating crown-of-thorns starfish Acanthaster spp. (COTS) have become to be amongst the most severe threats to coral reefs worldwide. Although most research has focused on COTS early development, it remains unclear how COTS populations will keep pace with changing ocean conditions. Since reproduction is a key process contributi...
Article
Full-text available
Leptoseris troglodyta , a cavernicolous azooxanthellate scleractinian coral, was found in a number of submarine caves openings at mesophotic depth (65–90 m) on the fore reefslopes of the reefs of Mayotte. It is the first record of the species in the Indian Ocean and at mesophotic depths.
Article
Full-text available
Monitoring potentially devastating coral-eating crown-of-thorns starfish (COTS) populations at scales relevant to management is a challenging task. Here, we investigated a citizen science approach to detect COTS outbreaks and prioritize management responses. Between 2014 and 2018, 38 000 COTS were recorded through 641 online observation reports sub...
Article
Full-text available
Internal Transcribed Spacer structures are important in preserving accessibility to specific enzymes for the maturation of rRNAs. ITS1 sequences reported in the literature in Crustaceans range between 182 and 820 bp and are characterized by the absence of repeats or the presence of only a limited number of microsatellites. Here, we sequenced ITS1 f...
Article
Full-text available
Without drastic efforts to reduce carbon emissions and mitigate globalized stressors, tropical coral reefs are in jeopardy. Strategic conservation and management requires identification of the environmental and socioeconomic factors driving the persistence of scleractinian coral assemblages—the foundation species of coral reef ecosystems. Here, we...
Article
Full-text available
The functioning of tropical coral reefs is imperilled by climate change, overfishing, and decreasing water quality. Maintaining their capacity to provide goods and services will critically depend on our ability to monitor their functioning at appropriate spatial and temporal scales. Given the constraints of traditional methods to respond to those n...
Article
Full-text available
Coral recruitment refers to the processes allowing maintenance and renewal of coral communities. Recruitment success is therefore indispensable for coral reef recovery after disturbances. Recruitment processes are governed by a variety of factors occurring at all spatial and temporal scales, from centimetres to hundreds of kilometres. In the presen...
Article
Full-text available
Coral reef assemblages generally form gradients of spatial structures which are governed by a variety of interacting physical and biological processes that vary in intensity, frequency, and spatial scale. Assessing the structure of contemporary reef assemblages may help to understand future changes and to identify appropriate conservation actions....
Book
Full-text available
Dans le cadre de la programmation 2016-2020 du réseau « Récifs » de l'IFRECOR, plusieurs collectivités ont insisté sur l’importance de définir des protocoles de suivi opérationnels et standardisés ainsi que d’accompagner les gestionnaires sur la conduite à tenir en cas de blanchissement corallien. Ce besoin est renforcé au niveau international par...
Article
Full-text available
Previous observations suggested that microbial communities contribute to coral health and the ecological resilience of coral reefs. However, most studies of coral microbiology focused on prokaryotes and the endosymbiotic algae Symbiodinium. In contrast, knowledge concerning diversity of other protists is still lacking, possibly due to methodologica...
Preprint
Full-text available
Ecosystems worldwide are suffering from climate change. For example, the coral reef ecosystems are globally threatened by increasing sea surface temperatures. However gene expression plasticity provides the potential for organisms to respond rapidly and effectively to environmental change, and would be favored in variable environments. In this stud...
Article
Full-text available
Populations of marine organisms on coral reef islands (CRI) are connected in space and time by seawater that transports propagules of plants, animals, and algae. Yet, despite this reality, it is often assumed that routine replenishment of populations of marine organisms on CRI is supported by locally-sourced propagules (hereafter, larvae). Followin...
Article
Full-text available
Coral reefs are increasingly threatened by various types of disturbances, and their recovery is challenged by accelerating, human-induced environmental changes. Recurrent disturbances reduce the pool of mature adult colonies of reef-building corals and undermine post-disturbance recovery from newly settled recruits. Using a long-term interannual da...
Presentation
Managing unpredictable, potentially devastating populations of Acanthaster spp., the crown-of-thorns starfish (COTS) is a significant issue across the Indo-Pacific where this voracious coral-eating species is historically a threat. Major alterations of coral reef ecosystems resulting from massive coral loss and subsequent cascading effects on coral...
Article
Full-text available
Outbreaks of predatory crown-of-thorns seastars (COTS) can devastate coral reef ecosystems, yet some corals possess mutualistic guardian crabs that defend against COTS attacks. However, guarded corals do not always survive COTS outbreaks, with the ecological mechanisms sealing the fate of these corals during COTS infestations remaining unknown. In...
Article
Full-text available
Background Although the term holobiont has been popularized in corals with the advent of the hologenome theory of evolution, the underlying concepts are still a matter of debate. Indeed, the relative contribution of host and environment and especially thermal regime in shaping the microbial communities should be examined carefully to evaluate the p...
Article
Full-text available
Outbreaks of the coral predator Acanthaster spp., the crown-of-thorns seastar (COTS), cause major coral declines across the Indo-Pacific. However, the processes surrounding the initiation and propagation of COTS outbreaks are still unclear. We observed COTS outbreak abundances on several mid-shelf and inner-barrier reefs in the southern section of...
Technical Report
Full-text available
L’aggravation du risque acanthaster à l’échelle régionale constitue un problème réel dans le contexte des scénarios de changement climatique actuels. Partant du constat que la majorité des petits pays océaniens insulaires ne disposent pas de dispositifs de surveillance adaptés, le projet OREANET (Oceania REgional Acanthaster NETwork) constitue la p...
Article
Full-text available
Outbreaks of predatory crown-of-thorns seastars (COTS) can devastate coral reef ecosystems, yet some corals possess mutualistic guardian crabs that defend against COTS attacks. However, guarded corals do not always survive COTS outbreaks, with the ecological mechanisms sealing the fate of these corals during COTS infestations remaining unknown. In...
Chapter
Full-text available
Recruitment is now widely recognized as a fundamental process governing spatial patterns, dynamics, and maintenance of marine invertebrate communities. Moreover, recruitment is a critical factor for successful recovery following disturbances and thus resilience of ecosystems. Over the last decades, tropical coral reefs, which are one of the most di...
Article
Full-text available
Outbreaks of the predator crown-of-thorns seastar (COTS) Acanthaster planci cause widespread coral mortality across the Indo-Pacific. Like many marine invertebrates, COTS is a nocturnal species whose cryptic behaviour during the day can affect its detectability, particularly in structurally complex reef habitats that provide many refuges for benthi...
Article
Full-text available
Clipperton Atoll, one of the most isolated coral reefs worldwide, is of great scientific interest due to its geomorphology and high levels of endemism. This study explored the reef fish assemblage structure of Clipperton Atoll and its relationship with live coral cover. Nine stations were sampled at three sites and three depths (6, 12 and 20 m) aro...
Chapter
Full-text available
Description de l'état des récifs du territoire de Clipperton dans le cadre du plan d'action 2010-2015 de l'IFRECOR.
Article
Full-text available
Rapa (27°36′ S, 144°20′ W) is a small (~40 km2) volcanic island isolated in the Southern Austral Archipelago, where direct anthropogenic stressors are extremely limited. Here, we present the results of the first quantitative survey of coral community structure across habitats and depths around the island. Despite its geographical isolation in the d...
Article
We report here an interannual survey (2006–2012) of coral cover in the northwestern lagoon of New Caledonia, to assess the impact of an important dredging operation (August 2008–February 2010) associated with the construction of the largest nickel mining site in the Pacific. A BACI (Before-After Control-Impact) analysis failed to detect any signifi...