@article {8902, title = {Multiple phytoplankton community responses to environmental change in a temperate coastal system: A trait-based approach}, journal = {Frontiers in Marine Science}, volume = {9}, year = {2022}, month = {Jun-10-2022}, abstract = {The effect of environmental change in structuring the phytoplankton communities of the coastal waters of the Eastern English Channel was investigated by applying a trait-based approach on two decades (1996-2019) of monitoring on diatoms and\ Phaeocystis. We show that phytoplankton species richness in an unbalanced nutrient supply context was influenced by wind-driven processes, ecological specialization for dissolved inorganic phosphorous, temporal niche differentiation, and a competition-defense and/or a growth-defense trade-off, a coexistence mechanism where weak competitors (i.e., slower growing) are better protected against predation. Under the influence of both environmental perturbations (e.g., wind-driven processes, freshwater influence, unbalanced nutrient levels) and biotic interactions (e.g., competition, predation, facilitation), phytoplankton species exhibited specific survival strategies such as investment on growth, adaptation and tolerance of species to environmental stresses, silicification and resource specialization. These strategies have led to more speciose communities, higher productivity, functional redundancy and stability in the last decade. Our results revealed that the unbalanced nutrient reduction facilitated\ Phaeocystis\ blooms and that anthropogenic climate warming and nitrate reduction may threaten the diatom communities of the eastern English Channel in a near future. Our results provide strong support for biogeographical historical and niche-based processes in structuring the phytoplankton community in this temperate region. The variety of species responses that we characterized in this region may help to better understand future changes in pelagic ecosystems, and can serve as a basis to consider functional approaches for future ecosystem management.}, doi = {https://doi.org/10.3389/fmars.2022.914475}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2022.914475/full}, author = {Elsa Breton and Goberville, Eric and Benoit Sautour and Ouadi, Anis and Skouroliakou, Dimitra-Ioli and Seuront, Laurent and Gr{\'e}gory Beaugrand and Kl{\'e}parski, Lo{\"\i}ck and Crouvoisier, Muriel and Pecqueur, David and Salmeron, Christophe and Cauvin, Arnaud and Poquet, Adrien and Garcia, Nicole and Gohin, Francis and Christaki, Urania} } @article {8150, title = {Seasonal Variations in the Biodiversity, Ecological Strategy, and Specialization of Diatoms and Copepods in a Coastal System With Phaeocystis Blooms: The Key Role of Trait Trade-Offs}, journal = {Frontiers in Marine Science}, volume = {8}, year = {2021}, month = {09/2021}, pages = {1178}, abstract = {Although eutrophication induced by anthropogenic nutrient enrichment is a driver of shifts in community composition and eventually a threat to marine biodiversity, the causes and consequences on ecosystem functioning remain greatly unknown. In this study, by applying a trait-based approach and measuring niche breadth of diatoms and copepods, the drivers and underlying mechanisms of the seasonal species succession of these ecological communities in a coastal system dominated in spring by\ Phaeocystis\ blooms were explored. It is suggested that the seasonal succession of diatoms and copepods is the result of several trade-offs among functional traits that are controlled by the seasonal abiotic and biotic pressure encountered by the plankton communities. The results of this study highlight that a trade-off between competition and predator, i.e., weak competitors are better protected against predation, plays an important role in promoting plankton species richness and triggers the\ Phaeocystis\ bloom. As often observed in eutrophicated ecosystems, only the biotic homogenization of the copepod community and the shift in the diet of copepods toward\ Phaeocystis\ detrital materials have been detected during the\ Phaeocystis\ bloom. The diatom and copepod communities respond synchronously to fluctuating resources and biotic conditions by successively selecting species with specific traits. This study confirms the key role of competition and predation in controlling annual plankton succession.}, issn = {2296-7745}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2021.656300/full}, author = {Breton, Elsa and Christaki, Urania and Benoit Sautour and Demonio, Oscar and Skouroliakou, Dimitra-Ioli and Gr{\'e}gory Beaugrand and Seuront, Laurent and Kl{\'e}parski, Lo{\"\i}ck and Poquet, Adrien and Nowaczyk, Antoine and Muriel Crouvoisier and Ferreira, Sophie and Pecqueur, David and Salmeron, Christophe and Brylinski, Jean-Michel and Lheureux, Arnaud and Goberville, Eric} } @article {Chevillot2019473, title = {Global Changes Jeopardize the Trophic Carrying Capacity and Functioning of Estuarine Ecosystems}, journal = {Ecosystems}, volume = {22}, number = {3}, year = {2019}, note = {cited By 2}, pages = {473-495}, publisher = {Springer New York LLC}, abstract = {At the interface between terrestrial and marine biomes, estuaries display high ecological productivity and provide goods and services to humans. Associated with many ecological functions, they are nursery, refuge, and growing areas for many species fish. These ecological functions and services depend on both their ecological production and trophic carrying capacity and the durability of food web functioning. These transitional key habitats undergo both strong anthropogenic pressures and climatic influences that impact the structure and dynamics of estuarine biodiversity. In this context, we explore, here, three decades of the Gironde estuary ecosystem history to detect the food web{\textquoteright}s response to global changes-induced effect on biodiversity. At least two Ecological Abrupt Shifts associated with deep modifications in the biodiversity at most trophic levels have been documented for this particular ecosystem. Three food web models were thus calibrated, one for each of the three periods discriminated by the two shifts that occurred at the end of the 1980s and the beginning of the 2000s. Results highlighted that the ecotrophic efficiency estimate for subtidal macrofauna and shrimps reached the maximum possible values during the last period. This could mean that the Gironde estuary fully reached its trophic carrying capacity due to a food limitation especially for benthos demersal fish. We also observed a significant decrease in some food web indicators (such as Average Mutual Information, System Omnivory Index, and Average Path Length) usually associated with ecosystem stress, suggesting a significant impact of global change on the Gironde estuary ecosystem health and questioning the sustainability of the ecological functions associated with this ecosystem. {\textcopyright} 2018, Springer Science+Business Media, LLC, part of Springer Nature.}, keywords = {benthos, carrying capacity, demersal fish, ecosystem function, ecosystem health, food limitation, food web, France, Gironde Estuary, Global change, network analysis, trophic environment}, issn = {14329840}, doi = {10.1007/s10021-018-0282-9}, url = {https://link.springer.com/article/10.1007/s10021-018-0282-9}, author = {Chevillot, X. and Tecchio, S. and Chaalali, A. and Lassalle, G. and Selleslagh, J. and Castelnaud, G. and David, V. and Guy Bachelet and Nathalie Niquil and Benoit Sautour and Lobry, J.} } @article {6085, title = {Local changes in copepod composition and diversity in two coastal systems of Western Europe}, journal = {Estuarine, Coastal and Shelf Science}, year = {2019}, pages = {106304}, author = {Richirt, Julien and Goberville, Eric and Ruiz-Gonzalez, Vania and Benoit Sautour} } @article {5824, title = {{Climatic Facilitation of the Colonization of an Estuary by Acartia tonsa}}, journal = {PLoS ONE}, volume = {8}, year = {2013}, abstract = {

Global change has become a major driving force of both terrestrial and marine systems. Located at the interface between these two realms, estuarine ecosystems are probably the place where both direct and indirect effects of human activities conspire together to affect biodiversity from phytoplankton to top predators. Among European estuarine systems, the Gironde is the largest estuary of Western Europe and many studies have provided evidence that it has been affected by a variety of anthropogenic stressors such as thermal and chemical pollution, physical alterations and exploitation, especially for maritime traffic. In such a context, species introduction is also a current major issue with the establishment of strong competitive species that could lead to ecosystem reorganization with potential decrease or even disappearance of native species. In the Gironde estuary, this hypothesis was proposed for the invasive shrimp species Palaemon macrodactylus as a decrease in the native species abundance was observed at the same time. Although species introduction often takes place via ballast water, the influence of climate-driven changes on the establishment of new species remains a key issue. The calanoid copepod Acartia tonsa, observed in the Gironde estuary for the first time in 1983, have since colonized most part of the estuary, reaching a level of abundance comparable to the dominant native species Eurytemora affinis. In this study, using both the concept of the ecological niche sensu Hutchinson (fundamental and realized niches) and statistical models, we reveal that the dynamics of the colonization of A. tonsa was facilitated by environmental conditions that have become closer to its environmental optimum with respect to temperature and salinity.

}, issn = {19326203}, author = {Chaalali, Aur{\'e}lie and Gr{\'e}gory Beaugrand and Virginie Raybaud and Goberville, Eric and David, Val{\'e}rie and Bo{\"e}t, Philippe and Benoit Sautour} } @article {5827, title = {{Early evaluation of coastal nutrient over-enrichment: New procedures and indicators}}, journal = {Marine Pollution Bulletin}, volume = {62}, year = {2011}, pages = {1751{\textendash}1761}, abstract = {

Recent studies have provided compelling evidence for an accelerated anthropogenic impact on coastal systems, resulting in intense inputs of materials and nutrients from the continent. This has led scientists and policymakers to encourage the implementation of monitoring programmes, which have resulted in the multiplicity of datasets. However surprisingly, only a few attempts have been made to couple observations with statistical and mathematical tools to detect, as soon as the data become available perturbations in coastal systems. Here, we propose new mathematical procedures to evaluate the state of a system, based on the building of relative reference state and indicators of nutrient over-enrichment. The techniques were tested in some French coastal systems using data from the programme SOMLIT. Applied to this dataset, the multivariate procedures rapidly identified and evaluated anthropogenic nutrient anomalies from the continent on three sites (Wimereux, Roscoff and Villefranche-sur-Mer) from 1997 onwards. {\textcopyright} 2011 Elsevier Ltd.

}, keywords = {Indicators, Monitoring, Multivariate statistical analyses, Nutrient over-enrichment, Relative reference states, SOMLIT}, author = {Goberville, Eric and Gr{\'e}gory Beaugrand and Benoit Sautour and Paul Tr{\'e}guer} } @article {5828, title = {{Evaluation of coastal perturbations: A new mathematical procedure to detect changes in the reference state of coastal systems}}, journal = {Ecological Indicators}, volume = {11}, year = {2011}, pages = {1290{\textendash}1300}, abstract = {

The pressure exerted by human activities on living systems has become so intense that it is inspiring the inception of a global network of monitoring of the biosphere and the use of robust statistical procedures to detect potential changes. Here, we propose a new multivariate non-parametric procedure, based on the Mahalanobis generalised distance and a simplification of the multiple response permutation procedure to identify rapidly changes in any natural systems. The procedure can be virtually coupled on all monitoring programmes and is not influenced by missing data, a common feature found in many ecological databases. In France, physical, chemical and biological variability of coastal waters have been monitored since 1997 by the SOMLIT Network. Applied to this data set, this technique enabled a first quantification of the impacts of human disturbance through changes in the concentration of nutrients. Our results revealed how climate may interact with anthropogenic pressure to alter coastal marine systems and suggest a synergism between nutrient enrichment, human activities and local climatic conditions. Indeed some effects of climate (e.g. insolation duration - increase in duration of daylight) may attenuate the fertility of coastal systems, while some others (e.g. precipitation) amplify the human signals. {\textcopyright} 2011 Elsevier Ltd.

}, keywords = {Anthropogenic nutrient enrichment, Climate Change, Coastal systems, Monitoring, SOMLIT}, issn = {1470160X}, author = {Goberville, Eric and Gr{\'e}gory Beaugrand and Benoit Sautour and Paul Tr{\'e}guer} } @article {5829, title = {{Climate-driven changes in coastal marine systems of western Europe}}, year = {2010}, abstract = {

Coastal marine systems, the interface between the ocean and terrestrial realms, are among the most important systems on the planet both ecologically and economically because of their crucial role in earth system functioning. Although direct impacts of human activities on physical, chemical and biological components of these systems have been widely documented, the potential influence of climate variability is less well known. Here, we used data from Service d{\textquoteright}Observation en Milieu Littoral (SOMLIT), a marine monitoring programme that has since 1997 collected samples at 12 sites located along the French coasts from 42{\textdegree} to 51{\textdegree} N. Applying standardised principal component analysis (PCA), we documented the year-to-year fluctuations in these coastal systems and evaluated the potential influence of climate variability using data on atmospheric circulation (wind intensity and direction), precipitation and temperature. Our study revealed a pronounced sensitivity of these systems to climate variability. As the impact of climate change may become more prominent in the next decades, this study suggests that climate might strongly influence the marine coastal environment and act in synergism with other anthropogenic pressures to alter the state and functioning of biological and ecological systems and the services they provide. {\textcopyright} Inter-Research 2010 {\textperiodcentered} www.int-res.com.

}, doi = {10.3354/meps08564}, author = {Goberville, Eric and Gr{\'e}gory Beaugrand and Benoit Sautour and Paul Tr{\'e}guer and SOMLIT, Team} }