Past, present and future eutrophication in the North-East Atlantic coastal waters Xavier Desmit, Geneviève Lacroix, Valérie Dulière Royal Belgian Institute of Natural Sciences (RBINS), OD Nature, Belgium Vincent Thieu, Marie Silvestre, Gilles Billen, Paul Passy, Luis Lassaletta, Josette Garnier UMR METIS, Université Pierre et Marie Curie (UPMC)/CNRS, Paris, France Alain Ménesguen, Bénédicte Thouvenin, Morgan Dussauze Dynamiques de l Environnement Côtier (DYNECO), IFREMER, Plouzané, France Francisco Campuzano, Ramiro Neves Instituto do Mar (IMAR), Portugal Nathalie Gypens Ecologie des systèmes aquatiques (ESA), Université Libre de Bruxelles (ULB), Brussels, Belgium Hermann Lenhart University of Hamburg (UHAM), Germany Tineke Troost, Hans Los Deltares, The Netherlands Johan Van der Molen Centre for Environment, Fisheries and Aquaculture Science (CEFAS), UK
Introduction eutrophication in the world Great Acceleration (Steffen et al. 211, Ambio) Atm. CO2 conc. Fertilizer consumption N fluxes to coastal zones Aquatic Dead Zones by R. Simmon and J. Allen (NASA Earth Observatory) Dead zones affect 4 marine ecosystems (Diaz and Rosenberg 28, Science)
Introduction eutrophication in the NEA Remote Sensing Chl P9 (2-21) High Chlorophyll a N an P excess with respect to Si Consequences: Dead zones Ecosystem disturbance HABs (toxicity) North East Atlantic (NEA) Hannie van Pagee (Texel)
Introduction objectives of EMoSEM Ecosystem Models as Support to Eutrophication Management Objectives 1. To scale current coastal eutrophication problems against natural status (pristine situation) 2. To identify future scenarios of nutrient reduction in the river watersheds of NEA and assess the impact of these scenarios in the sea
Method: modelling approach Develop and combine 4 models Describe the river-ocean continuum in the NEA PyNuts Generic river-basin model Link eutrophication to anthropogenic inputs
Method: Generic river-basin model PyNuts Morphology and Reservoirs PyNuts Input for the 3 marine models
Method: marine models MIRO&CO ECO-MARS3D BIOPCOMS Hydrodynamic model Coupling Biogeochemical model Adapted from Lancelot et al. 25 Models : Chla P9 grow
Results: reference (REF) vs. pristine (PRI) Scale current vs. pristine eutrophication across the NEA Reference (REF) Present situation (2-21) RBINS Pristine (PRI) Past situation Forested lands No anthropogenic nutrients Unperturbed hydrology
Results: reference (REF) vs. pristine (PRI) Chl P9 (µg L -1 ) Winter DIN (µmol L -1 ) Winter DIP (µmol L -1 ) 8 3 REF REF REF 1 Chl P9 (µg L -1 ) Winter DIN (µmol L -1 ) Winter DIP (µmol L -1 ) 8 3 1 PRI PRI PRI
Results: future scenarios Pristine (PRI) Current (REF) 2-21 «Realistic» future nutrient reduction scenarios Improved wastewater treatment (UWWTD) + complete ban of P from washing powders Good Agricultural Practices (GAP) + UWWTD (catch crops, reasonable fertilization) Relocalized production, organic farming, demitarian diet (LocOrgDem) + UWWTD Almost achieved! Focus on N Focus on N
Results: LocOrgDem scenario Localized production Organic farming Demitarian diet N,P
Results: LocOrgDem in rivers Reference Poor to very poor status NO 3-, mgn l -1 Annual average Medium to very good status NO 3-, mgn l -1 Annual average LocOrgDem (incl. UWWTD)
Results: LocOrgDem in marine systems Chl P9 (µg L -1 ) Winter DIN (µmol L -1 ) Winter DIP (µmol L -1 ) 8 3 REF REF REF 1 Chl P9 (µg L -1 ) 8 Winter DIN (µmol L -1 ) Winter DIP (µmol L -1 ) 3 1 LOD LOD LOD
Results: Phytoplankton Functional Types Diatoms Phaeocystis colonies
Results: Phytoplankton and Zooplankton Modelled plankton biomass in the Southern Bight of the North Sea Multiyear mean time series (2-21) in Belgian location 33 Pristine Reference LocOrgDem The current eutrophication does not improve significantly the food web production, and merely enhances undesirable blooms of colonial Phaeocystis.
Conclusions The current status of coastal eutrophication across the NEA remains problematic Chlorophyll a P9 The pristine situation scales anthropogenic eutrophication NO 3- mgn.l -1 2-21 annual averages very good (<.45) good (.45-2.25) The LocOrgDem scenario REF is promissing PRI and it gives some lines of thought medium (2.25-5.65) poor (5.65-11.3) + additional scenarios of P reduction are in preparation very poor (>11.3) DIN Mitigating eutrophication may require paradigmatic changes at different levels and combines a reorganization of the agro-food systems with societal choices
Thank you! http://odnature.naturalsciences.be/emosem Desmit et al. In prep. Xavier Desmit, Geneviève Lacroix, Valérie Dulière Royal Belgian Institute of Natural Sciences (RBINS), OD Nature, Belgium Funding partners Vincent Thieu, Gilles Billen, Marie Silvestre, Paul Passy, Luis Lassaletta, Josette Garnier UMR METIS, Université Pierre et Marie Curie (UPMC)/CNRS, Paris, France Alain Ménesguen, Bénédicte Thouvenin, Morgan Dussauze Dynamiques de l Environnement Côtier (DYNECO), IFREMER, Plouzané, France Francisco Campuzano, Ramiro Neves, João Sobrinho, Ligia Pinto Instituto do Mar (IMAR), Portugal Christiane Lancelot, Nathalie Gypens Ecologie des systèmes aquatiques (ESA), Université Libre de Bruxelles (ULB), Brussels, Belgium Hermann Lenhart University of Hamburg (UHAM), Germany Tineke Troost, Hans Los Deltares, The Netherlands Johan Van der Molen Centre for Environment, Fisheries and Aquaculture Science (CEFAS), UK