@article {8143, title = {Cumulative effects of marine renewable energy and climate change on ecosystem properties: Sensitivity of ecological network analysis}, journal = {Ecological Indicators}, volume = {121}, year = {2021}, month = {Jan-02-2021}, pages = {107128}, issn = {1470160X}, doi = {10.1016/j.ecolind.2020.107128}, url = {https://linkinghub.elsevier.com/retrieve/pii/S1470160X20310670}, author = {Nogues, Quentin and Raoux, Aurore and Araignous, Emma and Chaalali, Aur{\'e}lie and Hattab, Tarek and Leroy, Boris and Ben Rais Lasram, Frida and David, Val{\'e}rie and Le Loc{\textquoteright}h, Francois and Dauvin, Jean-Claude and Nathalie Niquil} } @article {5039, title = {Evaluating ecosystem-level anthropogenic impacts in a stressed transitional environment: The case of the Seine estuary}, journal = {ECOLOGICAL INDICATORS}, volume = {61}, year = {2016}, month = {02/2016}, pages = {833-845}, abstract = {

During 2002-2005, a new container terminal in the commercial harbour of Le Havre, named "Port2000", was built on the northern flank of the Seine estuary, northern France. This extension is already known to have modified the estuary current and sediment dynamics, as well as reducing biomass of the suprabenthos assemblage, for the whole downstream part of the system. However, studies on other biotic communities were largely inconclusive, and an ecosystem-wide analysis was still lacking. Here, we performed a before/after study of ecosystem dynamics of the different habitats of the Seine estuary, using a Linear Inverse Modelling technique (LIM-MCMC) to estimate all flows occurring in the food web. Ecological Network Analysis indices were calculated, summarising ecosystem functioning traits and giving indications about the habitat health status. Results showed that the southern flank (FS, Fosse Sud) exhibits all characteristics to be considered as the least stressed habitat of the estuary: system activity and functional specialisation of flows were stable between periods, ecosystem recycling processes and detrital dynamics were also stable; an increase in trophic specialisation (decrease in system omnivory) was the only change confirming a general ecological succession. The northern flank (FN, Fosse Nord), where the actual terminal was built, showed a food web with increased importance of lower trophic levels (increased detritivory and carbon recycling), increased stability and flow efficiency, but possibly regressed to a previous step in ecological succession. In the central navigation channel (CH), patterns of network indices were overall inconclusive and the general image is one of a constantly shifting food web, a condition possibly caused by the year-round dredging activities. The functioning of the Seine estuary especially of FN and FS - seems to have been modified by the combination of harbour construction and the related mitigation measures. Network indices partially captured this combination of changes and, although not fully operational yet, they are promising tools to comply with the European Union mandate of defining ecosystem health status. (c) 2015 Elsevier Ltd. All rights reserved.

}, issn = {{1470-160X}}, doi = {{10.1016/j.ecolind.2015.10.036}}, author = {Samuele Tecchio and Chaalali, Aur{\'e}lie and Raoux, Aurore and Rius, Armonie Tous and Lequesne, Justine and Girardin, Valerie and G{\'e}raldine Lassalle and Cachera, Marie and Riou, P and Lobry, Jeremy and Dauvin, Jean-Claude and Nathalie Niquil} } @article {5038, title = {From species distributions to ecosystem structure and function: A methodological perspective}, journal = {ECOLOGICAL MODELLING}, volume = {334}, year = {2016}, month = {08/2016}, pages = {78-90}, abstract = {

{As species biology and ecology is profoundly influenced by climate, any climatic alteration may have severe consequences on marine pelagic ecosystems and their food webs. It remains challenging to estimate the influence of climate on both structural and functional properties of food webs. In this study, we proposed an innovative approach to assess the propagating effects of climate change on ecosystem food web. The approach is based on a sensitivity analysis of a food-web model, a linear inverse model using a Monte Carlo method coupled with a Markov Chain, in which changes in the values of parameters are driven by external Ecological Niche Model outputs. Our sensitivity analysis was restricted to parameters regarding a keystone functional group in marine ecosystems, i.e. small pelagic fish. At the ecosystem level, the consequences were evaluated using both structural and functional ecological network indices. The approach is innovative as it is the first time that these three methods were combined to assess ecological network indices sensitivity to future climatic pressure. This coupling method was applied on the French continental shelf of the Bay of Biscay for which a food-web model already exists and where future changes in the distribution of small pelagic fish have already been examined through model building and projections. In response to the sensitivity analysis corresponding to an increase in small pelagics production only, our results suggested a more active system with an intense plankton-small pelagics-seabirds chain and an efficient recycling to maximize detritus use in the system in relation with detritus export. All results combined together seemed to be in favor of a system adapting to sustain the tested increase in production of small pelagic planktivores. Finally, regarding the innovative combination of numerical tools presented, even if further investigations are still necessary to get a more realistic view of cumulative effects resulting from one given pressure (or more) on a food web (e.g. altering different biological compartments at the same time), the Ecological Network Analysis indices values showed a higher variability under the scenarios of change. Our study thus pointed out a promising methodology to assess propagating changes in structural and functional ecosystem properties. (C) 2016 Elsevier B.V. All rights reserved.}

}, issn = {{0304-3800}}, doi = {{10.1016/j.ecolmodel.2016.04.022}}, author = {Chaalali, Aur{\'e}lie and Gr{\'e}gory Beaugrand and Virginie Raybaud and G{\'e}raldine Lassalle and Saint-B{\'e}at, B and Le Loc{\textquoteright}h, Francois and Bopp, Laurent and Samuele Tecchio and Safi, Georges and Chifflet, Marina and Lobry, Jeremy and Nathalie Niquil} } @article {5041, title = {Incorporating food-web parameter uncertainty into Ecopath-derived ecological network indicators}, journal = {ECOLOGICAL MODELLING}, volume = {313}, year = {2015}, month = {OCT 10}, pages = {29-40}, abstract = {

Ecological network analysis (ENA) provides numerous ecosystem level indices offering a valuable approach to compare and categorize the ecological structure and function of ecosystems. The inclusion of ENA methods in Ecopath with Ecosim (EwE) has insured their continued contribution to ecosystem-based management. In EwE, ENA-derived ecological conclusions are currently based on single values of ENA indices calculated from a unique input flow matrix. Here, we document an easy-to-use routine that allows EwE users to incorporate uncertainty in EwE input data into the calculation of ENA indices. This routine, named ENAtool, is a suite of Matlab functions that performs three main steps: (1) import of an existing Ecopath model and its associated parameter uncertainty values in the form of uncertainty intervals into Matlab; (2) generation of an ensemble of Ecopath models with the same structure as the original, and with parameter values varying based on the prescribed uncertainty limits; and (3) calculation of a set of 13 ENA indices for each ensemble member (one set of flow values) and of summary statistics across the whole ensemble. This novel routine offers the opportunity to calculate ENA indices ranges and confidence intervals, and thus to perform quantitative data analyses. An application of ENAtool on a pre-existing Ecopath model of the Bay of Biscay continental shelf is presented, with a focus on the robustness of previously published ENA-based ecological traits of this ecosystem when the newly introduced uncertainty values are added. We also describe the sensitivity of the ENAtool results to both the number of ensemble members used and to the uncertainty interval set around each input parameter. Ecological conclusions derived from EwE, particularly those regarding the comparison of structural and functional elements for a range of ecosystem types or the assessment of ecosystem properties along gradients of environmental conditions or anthropogenic disturbances, will gain in statistical interpretability. (C) 2015 Elsevier B.V. All rights reserved.

}, issn = {{0304-3800}}, doi = {{10.1016/j.ecolmodel.2015.05.036}}, author = {Guesnet, Vanessa and G{\'e}raldine Lassalle and Chaalali, Aur{\'e}lie and Kearney, Kelly and Saint-B{\'e}at, B and Karimi, Battle and Grami, Boutheina and Samuele Tecchio and Nathalie Niquil and Lobry, Jeremy} } @article {5042, title = {The mosaic of habitats of the Seine estuary: Insights from food-web modelling and network analysis}, journal = {ECOLOGICAL MODELLING}, volume = {312}, year = {2015}, month = {09/2015}, pages = {91-101}, abstract = {

Ecological network analysis was applied in the Seine estuary ecosystem, northern France, integrating ecological data from the years 1996 to 2002. The Ecopath with Ecosim (EwE) approach was used to model the trophic flows in 6 spatial compartments leading to 6 distinct EwE models: the navigation channel and the two channel flanks in the estuary proper, and 3 marine habitats in the eastern Seine Bay. Each model included 12 consumer groups, 2 primary producers, and one detritus group. Ecological network analysis was performed, including a set of indices, keystoneness, and trophic spectrum analysis to describe the contribution of the 6 habitats to the Seine estuary ecosystem functioning. Results showed that the two habitats with a functioning most related to a stressed state were the northern and central navigation channels, where building works and constant maritime traffic are considered major anthropogenic stressors. The strong top-down control highlighted in the other 4 habitats was not present in the central channel, showing instead (i) a change in keystone roles in the ecosystem towards sediment-based, lower trophic levels, and (ii) a higher system omnivory. The southern channel evidenced the highest system activity (total system throughput), the higher trophic specialisation (low system omnivory), and the lowest indication of stress (low cycling and relative redundancy). Marine habitats showed higher fish biomass proportions and higher transfer efficiencies per trophic levels than the estuarine habitats, with a transition area between the two that presented intermediate ecosystem structure. The modelling of separate habitats permitted disclosing each one{\textquoteright}s response to the different pressures, based on their a priori knowledge. Network indices, although non-monotonously, responded to these differences and seem a promising operational tool to define the ecological status of transitional water ecosystems. (C) 2015 Elsevier B.V. All rights reserved.

}, issn = {{0304-3800}}, doi = {{10.1016/j.ecolmodel.2015.05.026}}, author = {Samuele Tecchio and Rius, Armonie Tous and Dauvin, Jean-Claude and Lobry, Jeremy and G{\'e}raldine Lassalle and Morin, Jocelyne and Bacq, Nicolas and Cachera, Marie and Chaalali, Aur{\'e}lie and Villanueva, Maria Ching and Nathalie Niquil} } @article {5048, title = {A new modeling approach to define marine ecosystems food-web status with uncertainty assessment}, journal = {Progress in Oceanography}, volume = {135}, year = {2015}, pages = {37{\textendash}47}, author = {Chaalali, Aur{\'e}lie and Saint-B{\'e}at, B and G{\'e}raldine Lassalle and Le Loc{\textquoteright}h, Francois and Samuele Tecchio and Safi, Georges and Savenkoff, Claude and Lobry, Jeremy and Nathalie Niquil} } @article {5050, title = {Reaction of an estuarine food web to disturbance: Lindeman{\textquoteright}s perspective}, journal = {Marine Ecology Progress Series}, volume = {512}, year = {2014}, pages = {141{\textendash}154}, author = {Nathalie Niquil and Baeta, Alexandra and Marques, Jo{\~a}o Carlos and Chaalali, Aur{\'e}lie and Lobry, Jeremy and Patr{\'\i}cio, Joana} } @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} }