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7. Running Head: nutrient enrichment on a coral reef Landscape-scale patterns of nutrient enrichment in a coral reef ecosystem: implications for coral to algae phase shifts

Author

Adam, Thomas, Burkepile, Deron, Holbrook, Sally, Carpenter, Robert, Claudet, Joachim, Loiseau, Charles, Thiault, Lauric, Brooks, Andrew, Washburn, Libe, Schmitt, Russell, Marine Science Institute [Santa Barbara] (MSI), University of California [Santa Barbara] (UCSB), University of California-University of California, California State University [Northridge] (CSUN), Centre de recherches insulaires et observatoire de l'environnement (CRIOBE), Université de Perpignan Via Domitia (UPVD)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Excellence CORAIL (LabEX CORAIL), Institut de Recherche pour le Développement (IRD)-Université des Antilles et de la Guyane (UAG)-École des hautes études en sciences sociales (EHESS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de La Réunion (UR)-Université de la Polynésie Française (UPF)-Université de la Nouvelle-Calédonie (UNC)-Institut d'écologie et environnement-Université des Antilles (UA), University of California [Santa Barbara] (UC Santa Barbara), University of California (UC)-University of California (UC), Université de Perpignan Via Domitia (UPVD)-École Pratique des Hautes Études (EPHE), and Institut de Recherche pour le Développement (IRD)-Université des Antilles et de la Guyane (UAG)-École des hautes études en sciences sociales (EHESS)-École Pratique des Hautes Études (EPHE)

Subjects
[SDV.EE.ECO]Life Sciences [q-bio]/Ecology, environment/Ecosystems, [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography
Abstract

International audience; Nutrient pollution is altering coastal ecosystems worldwide. On coral reefs, excess nutrients can favor the production of algae at the expense of reef‐building corals, yet the role of nutrients in driving community changes such as shifts from coral to macroalgae is not well understood. Here we investigate the potential role of anthropogenic nutrient loading in driving recent coral‐to‐macroalgae phase shifts on reefs in the lagoons surrounding the Pacific island of Moorea, French Polynesia. We use nitrogen (N) tissue content and stable isotopes (δ15N) in an abundant macroalga (Turbinaria ornata) together with empirical models of nutrient discharge to describe spatial and temporal patterns of nutrient enrichment in the lagoons. We then employ time series data to test whether recent increases in macroalgae are associated with nutrients. Our results revealed that patterns of N enrichment were linked to several factors, including rainfall, wave‐driven circulation, and distance from anthropogenic nutrient sources, especially human sewage. Reefs near large watersheds, where inputs of N from sewage and agriculture are high, have been consistently enriched in N for at least the last decade. In many of these areas, corals have decreased and macroalgae have increased, while reefs with lower levels of N input have maintained high cover of coral and low cover of macroalgae. Importantly, these patchy phase shifts to macroalgae have occurred despite substantial island‐wide increases in the density and biomass of herbivorous fishes over the time period. Together, these results indicate that nutrient loading may be an important driver of coral‐to‐macroalgae phase shifts in the lagoons of Moorea even though the reefs harbor an abundant and diverse herbivore assemblage. These results emphasize the important role that bottom‐up factors can play in driving coral‐to‐macroalgae phase shifts and underscore the critical importance of watershed management for reducing inputs of nutrients and other land‐based pollutants to coral reef ecosystems

Published
2021

8. A fast-moving target: achieving marine conservation goals under shifting climate and policies

Author

European Cooperation in Science and Technology, Israel Science Foundation, Agencia Estatal de Investigación (España), Rilov, Gil, Fraschetti, Simonetta, Gissi, Elena, Pipitone, C., Badalamenti, F., Tamburello, Laura, Goriup, Paul, Mazaris, Antonios D., Garrabou, Joaquim, Benedetti-Cecchi, Lisandro, Danovaro, Roberto, Loiseau, Charles, Claudet, Joachim, Menini, Elisabetta, Katsanevakis, Stelios, European Cooperation in Science and Technology, Israel Science Foundation, Agencia Estatal de Investigación (España), Rilov, Gil, Fraschetti, Simonetta, Gissi, Elena, Pipitone, C., Badalamenti, F., Tamburello, Laura, Goriup, Paul, Mazaris, Antonios D., Garrabou, Joaquim, Benedetti-Cecchi, Lisandro, Danovaro, Roberto, Loiseau, Charles, Claudet, Joachim, Menini, Elisabetta, and Katsanevakis, Stelios

Abstract

In the Anthropocene, marine ecosystems are rapidly shifting to new ecological states. Achieving effective conservation of marine biodiversity has become a fast-moving target because of both global climate change and continuous shifts in marine policies. How prepared are we to deal with this crisis? We examined EU Member States Programs of Measures designed for the implementation of EU marine environmental policies, as well as recent European Marine Spatial Plans, and discovered that climate change is rarely considered operationally. Further, our analysis revealed that monitoring programs in marine protected areas are often insufficient to clearly distinguish between impacts of local and global stressors. Finally, we suggest that while the novel global Blue Growth approach may jeopardize previous marine conservation efforts, it can also provide new conservation opportunities. Adaptive management is the way forward (e.g., preserving ecosystem functions in climate change hotspots, and identifying and targeting climate refugia areas for protection) using Marine Spatial Planning as a framework for action, especially given the push for Blue Growth

Published
2020

9. Operationalizing risk-based cumulative effect assessments in the marine environment

Author

Stelzenmüller, Vanessa, Coll, Marta, Cormier, Roland, Mazaris, Antonios D., Pascual, Marta, Loiseau, Charles, Claudet, Joachim, Katsanevakis, Stelios, Gissi, Elena, Evagelopoulos, Athanasios, Rumes, Bob, Degraer, Steven, Ojaveer, Henn, Moller, Tiia, Giménez, Joan, Piroddi, Chiara, Markantonatou, Vasiliki, Dimitriadis, Charalampos, Stelzenmüller, Vanessa, Coll, Marta, Cormier, Roland, Mazaris, Antonios D., Pascual, Marta, Loiseau, Charles, Claudet, Joachim, Katsanevakis, Stelios, Gissi, Elena, Evagelopoulos, Athanasios, Rumes, Bob, Degraer, Steven, Ojaveer, Henn, Moller, Tiia, Giménez, Joan, Piroddi, Chiara, Markantonatou, Vasiliki, and Dimitriadis, Charalampos

Abstract

Ecosystem-based management requires an assessment of the cumulative effects of human pressures and environmental change. The operationalization and integration of cumulative effects assessments (CEA) into decision-making processes often lacks a comprehensive and transparent framework. A risk-based CEA framework that divides a CEA in risk identification, risk analysis and risk evaluation, could structure such complex analyses and facilitate the establishment of direct science-policy links. Here, we examine carefully the operationalization of such a risk-based CEA framework with the help of eleven contrasting case studies located in Europe, French Polynesia, and Canada. We show that the CEA framework used at local, sub-regional, and regional scales allowed for a consistent, coherent, and transparent comparison of complex assessments. From our analysis, we pinpoint four emerging issues that, if accurately addressed, can improve the take up of CEA outcomes by management: 1) framing of the CEA context and defining risk criteria; 2) describing the roles of scientists and decision-makers; 3) reducing and structuring complexity; and 4) communicating uncertainty. Moreover, with a set of customized tools we describe and analyze for each case study the nature and location of uncertainty as well as trade-offs regarding available knowledge and data used for the CEA. Ultimately, these tools aid decision-makers to recognize potential caveats and repercussions of management decisions. One key recommendation is to differentiate CEA processes and their context in relation to governance advice, marine spatial planning or regulatory advice. We conclude that future research needs to evaluate how effective management measures are in reducing the risk of cumulative effects. Changing governance structures takes time and is often difficult, but we postulate that well-framed and structured CEA can function as a strategic tool to integrate ecosystem considerations across multiple sectorial po

Published
2020

11. Operationalizing risk-based cumulative effect assessments in the marine environment

Author

Stelzenmüller, Vanessa, primary, Coll, Marta, additional, Cormier, Roland, additional, Mazaris, Antonios D., additional, Pascual, Marta, additional, Loiseau, Charles, additional, Claudet, Joachim, additional, Katsanevakis, Stelios, additional, Gissi, Elena, additional, Evagelopoulos, Athanasios, additional, Rumes, Bob, additional, Degraer, Steven, additional, Ojaveer, Henn, additional, Moller, Tiia, additional, Giménez, Joan, additional, Piroddi, Chiara, additional, Markantonatou, Vasiliki, additional, and Dimitriadis, Charalampos, additional

Published
2020
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14. A fast‐moving target: achieving marine conservation goals under shifting climate and policies

Author

Rilov, Gil, primary, Fraschetti, Simonetta, additional, Gissi, Elena, additional, Pipitone, Carlo, additional, Badalamenti, Fabio, additional, Tamburello, Laura, additional, Menini, Elisabetta, additional, Goriup, Paul, additional, Mazaris, Antonios D., additional, Garrabou, Joaquim, additional, Benedetti‐Cecchi, Lisandro, additional, Danovaro, Roberto, additional, Loiseau, Charles, additional, Claudet, Joachim, additional, and Katsanevakis, Stelios, additional

Published
2019
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19. Lecture des incrémentations journalières sur des otolithes d’anchois adulte : Pourquoi et comment faire ?

Author

Loiseau, Charles

Abstract

La population d’anchois du Golfe de Gascogne présente une grande variabilité dans le recrutement de jeunes individus à la population, si bien que le stock a quasiment disparu en 2005. Bien qu’aujourd’hui la population soit revenue à un niveau démographique satisfaisant, les mécanismes qui interviennent dans le succès du recrutement sont toujours mal connus. Le but de cette étude est d’estimer plus précisément un intervalle de temps, à l’intérieur de la période de ponte de l’anchois européen, dans lequel sont nés des anchois d’un an, donc recrutés à la population. La détermination d’âge annuel des poissons par la lecture des otolithes est commune, mais le rétro-calcul de la date d’éclosion d’individus adulte par lecture des stries journalières n’a, à ce jour, fait l’objet d’aucune publication. Nous mettons donc en évidence, sur des otolithes d’anchois échantillonnés lors de PELGAS 2004, la faisabilité d’une telle méthode. Les résultats obtenus indiquent, pour l’année concernée, un recrutement qui a lieu sur une courte période de temps (un mois), et en dehors du pic de ponte. De plus, la taille des individus d’un an, très variable, ne dépendrait pas de leur nombre de jours de croissance. Ces premiers résultats, obtenus par une méthode inédite, posent les bases d’une réflexion sur les premiers stades de vie de l’anchois et les facteurs qui régissent sa croissance et sa probabilité de recrutement à la population.

Published
2016

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