title: Inferring time-variable effects of nutrient enrichment on marine ecosystems using inverse modelling and ecological network analysis.
abstract: We combined data from an outdoor mesocosm experiment with carbon budget modelling and an ecological network analysis to assess the effects of continuous nutrient additions on the structural and functional dynamics of a marine planktonic ecosystem. The food web receiving no nutrient additions was fuelled by detritus, as zooplankton consumed 7.2 times more detritus than they consumed algae. Nutrient supply instantly promoted herbivory so that it was comparable to detritivory at the highest nutrient addition rate. Nutrient-induced food web restructuring reduced carbon cycling and decreased the average number of compartments a unit flow of carbon crosses before dissipation. Also, the efficiency of copepod production, the link to higher trophic levels harvestable by man, was lowered up to 35 times by nutrient addition, but showed signs of recovery after 9 to 11 days. The dependency of the food web on exogenous input was not changed by the nutrient additions.
authors.affiliation: Department of Sustainable Organic Chemistry and Technology, Research Group EnVOC, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium; Department of Environmental Management, Faculty of Environment, Hanoi University of Agriculture, Hanoi, Viet Nam; Laboratory of Environmental Toxicity and Aquatic Ecology, Ghent University, J. Plateaustraat 22, 9000 Ghent, Belgium. Electronic address: ducanh.luong@ugent.be.
authors.forename: Anh D
authors.initials: AD
authors.lastname: Luong
authors.affiliation: Research Unit in Environmental and Evolutionary Biology, Université de Namur, Rue de Bruxelles, 61, Namur, Belgium. Electronic address: frederik.delaender@unamur.be.
authors.forename: Frederik
authors.initials: F
authors.lastname: De Laender
authors.affiliation: Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway. Electronic address: yngvar.olsen@bio.ntnu.no.
authors.forename: Yngvar
authors.initials: Y
authors.lastname: Olsen
authors.affiliation: Department of Biotechnology, Norwegian University of Science and Technology, 7491 Trondheim, Norway. Electronic address: olav.vadstein@biotech.ntnu.no.
authors.forename: Olav
authors.initials: O
authors.lastname: Vadstein
authors.affiliation: Department of Sustainable Organic Chemistry and Technology, Research Group EnVOC, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium. Electronic address: jo.dewulf@ugent.be.
authors.forename: Jo
authors.initials: J
authors.lastname: Dewulf
authors.affiliation: Laboratory of Environmental Toxicity and Aquatic Ecology, Ghent University, J. Plateaustraat 22, 9000 Ghent, Belgium. Electronic address: colin.janssen@ugent.be.
authors.forename: Colin R
authors.initials: CR
authors.lastname: Janssen
mesh_terms: D000818:Animals; D018533:Biomass; D033342:Copepoda; D004463:Ecology; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D008962:Models, Theoretical; D009584:Nitrogen / Q000032:analysis; D010758:Phosphorus / Q000032:analysis*; D010933:Plankton / Q000145:classification / Q000254:growth & development; D010944:Plants; D012623:Seawater / Q000737:chemistry
chemical_list: D010758:Phosphorus; D009584:Nitrogen
keywords: Carbon budget; Ecological network analysis; Linear inverse model; Marine ecosystem; Nutrient enrichment