@article {8837, title = {The Merits of Loop Analysis for the Qualitative Modeling of Social-Ecological Systems in Presence of Offshore Wind Farms}, journal = {Frontiers in Ecology and Evolution}, volume = {9}, year = {2021}, month = {May-02-2022}, doi = {10.3389/fevo.2021.635798}, url = {https://www.frontiersin.org/articles/10.3389/fevo.2021.635798/full}, author = {Nathalie Niquil and Scotti, Marco and Fofack-Garcia, Rhoda and Haraldsson, Matilda and Thermes, Maud and Raoux, Aurore and Le Loc{\textquoteright}h, Francois and Maz{\'e}, Camille} } @article {5418, title = {Microbial parasites make cyanobacteria blooms less of a trophic dead-end than commonly assumed}, journal = {The ISME Journal}, volume = {12}, year = {2018}, pages = {1008-1020}, abstract = {

Les parasites sont pr{\'e}sents dans tous les {\'e}cosyst{\`e}mes et peuvent {\^e}tre {\`a} l{\textquoteright}origine de changements dans la structure et le fonctionnement des r{\'e}seaux trophiques. Cependant, {\`a} ce jour, nos connaissances concernant les effets des parasites sur la dynamique des r{\'e}seaux trophiques restent limit{\'e}es. Dans cette {\'e}tude, nous analysons le r{\^o}le de parasites microbiens (virus de bact{\'e}ries, phytoplancton et cyanobact{\'e}ries, et des chitrides parasites des cyanobact{\'e}ries) sur le transfert d{\textquoteright}{\'e}nergie et le fonctionnement du r{\'e}seau trophique au cours d{\textquoteright}un bloom de cyanobact{\'e}rie {\`a} l{\textquoteright}aide d{\textquoteright}un mod{\`e}le d{\textquoteright}Analyse Inverse Lin{\'e}aire. Cette mod{\'e}lisation a permis de mettre en {\'e}vidence l{\textquoteright}importance du broutage sur les bact{\'e}ries h{\'e}t{\'e}rotrophes {\`a} travers la voie microbienne (DOC -\> bact{\'e}ries -\> consommateurs), ainsi que la d{\'e}pendance des consommateurs vis {\`a} vis des bact{\'e}ries notamment pendant les blooms de cyanobact{\'e}ries. Au fur et {\`a} mesure que les bact{\'e}ries deviennent la principale source d{\textquoteright}{\'e}nergie des consommateurs, le syst{\`e}me adopte une structure plus complexe, en r{\'e}seau, s{\textquoteright}accompagnant d{\textquoteright}une augmentation de l{\textquoteright}omnivorie du syst{\`e}me. Cette derni{\`e}re pourrait {\^e}tre {\`a} l{\textquoteright}origine d{\textquoteright}une augmentation de la capacit{\'e} du syst{\`e}me {\`a} r{\'e}sister {\`a} l{\textquoteright}efflorescence des cyanobact{\'e}ries. Finalement, nous avons {\'e}galement mis en {\'e}vidence les effets de la destruction des cellules h{\^o}tes des cyanobact{\'e}ries par les chitrides sur la dynamique du r{\'e}seau trophique. En effet, cette derni{\`e}re faciliterait le broutage des cyanobact{\'e}ries et offrirait des voies alternatives aux consommateurs, ce qui augmenteraient la stabilit{\'e} du syst{\`e}me.

Parasites exist in every ecosystem and can have large influence on food-web structure and function, yet, we know little about parasites{\textquoteright} effect on food-web dynamics. Here we investigate the role of microbial parasitism (viruses of bacteria, phytoplankton and cyanobacteria, and parasitic chytrids on cyanobacteria) on the dynamics of trophic pathways and food-web functioning during a cyanobacteria bloom, using linear inverse food-web modeling parameterized with a 2-month long dataset (biomasses, infection parameters, etc.). We show the importance of grazing on heterotrophic bacteria (the microbial pathway: DOC -\> bacteria -\> consumer) and how consumers depended on bacteria during peak-cyanobacteria bloom, which abundance was partly driven by the viral activity. As bacteria become the main energy pathway to the consumers, the system takes a more web-like structure through increased omnivory, and may thereby facilitate the system{\textquoteright}s persistence to the cyanobacteria outbreak. We also showed how the killing of cyanobacteria host-cells by chytrids had important impact on the food-web dynamics by facilitating grazing on the cyanobacteria, and by offering alternative pathways to the consumers. This seemed to increase the system{\textquoteright}s ability to return to a mix of trophic pathways, which theoretically increases the stability of the system.

}, doi = {10.1038/s41396-018-0045-9}, url = {https://doi.org/10.1038/s41396-018-0045-9}, author = {Haraldsson, Matilda and M{\'e}lanie Gerphagnon and Bazin, Pauline and Samuele Tecchio and T{\'e}l{\'e}sphore Sime-Ngando and Nathalie Niquil} } @article {5037, title = {Benthic and fish aggregation inside an offshore wind farm: Which effects on the trophic web functioning?}, journal = {Ecological indicators}, volume = {72}, year = {2017}, month = {01/2017}, pages = {33-46}, abstract = {

As part of the energy transition, the French government is planning the construction of three offshore wind farms in Normandy (Bay of Seine and eastern part of the English Channel, north-western France) in the next years. These offshore wind farms will be integrated into an ecosystem already facing multiple anthropogenic disturbances such as maritime transport, fisheries, oyster and mussel farming, and sediment dredging. Currently no integrated, ecosystem-based study on the effects of the construction and exploitation of offshore wind farms exists, where biological approaches generally focused on the conservation of some valuable species or groups of species. Complementary trophic web modelling tools were applied to the Bay of Seine ecosystem (to the 50 km(2) area covered by the wind farm) to analyse the potential impacts of benthos and fish aggregation caused by the introduction of additional hard substrates from the piles and the turbine scour protections. An Ecopath ecosystem model composed of 37 compartments, from phytoplankton to seabirds, was built to describe the situation {\textquoteleft}{\textquoteleft}before{{\textquoteright}{\textquoteright}} the construction of the wind farm. Then, an Ecosim projection over 30 years was performed after increasing the biomass of targeted benthic and fish compartments. Ecological Network Analysis (ENA) indices were calculated for the two periods, {\textquoteleft}{\textquoteleft}before{{\textquoteright}{\textquoteright}} and {\textquoteleft}{\textquoteleft}after{{\textquoteright}{\textquoteright}}, to compare network functioning and the overall structural properties of the food web. Our main results showed (1) that the total ecosystem activity, the overall system omnivory (proportion of generalist feeders), and the recycling increased after the construction of the wind farm; (2) that higher trophic levels such as piscivorous fish species, marine mammals, and seabirds responded positively to the aggregation of biomass on piles and turbine scour protections; and (3) a change in keystone groups after the construction towards more structuring and dominant compartments. Nonetheless, these changes could be considered as limited impacts of the wind farm installation on this coastal trophic web structure and functioning. (C) 2016 Elsevier Ltd. All rights reserved.

}, issn = {{1470-160X}}, doi = {10.1016/j.ecolind.2016.07.037}, author = {Raoux, Aurore and Samuele Tecchio and Pezy, Jean-Philippe and G{\'e}raldine Lassalle and Degraer, Steven and Wilhelmsson, Dan and Cachera, Marie and Ernande, Bruno and Le Guen, Camille and Haraldsson, Matilda and Karine Granger{\'e} and Le Loc{\textquoteright}h, Francois and Dauvin, Jean-Claude and Nathalie Niquil} }