1 UMR Carrtel Research Center on Trophic Networks and Lake Ecosystems - Unit - Lake Observatory - Some results Bernard MONTUELLE

Global scientific context  functionning of alpine lakes ecosystems related to their watershed and the atmosphere  the effect of drivers, especially in the context of the present re-oligotrophisation dynamics and the climate change.  Integers the global change issues Land Uses Pollutions Regulations Standarts Climate - 3 Sub systems and specific functionnings -Fluxes and internal exchanges - External drivers and exchanges Lake Water uses (fishing, recreational…) flux./proc. Flux./proc. Watershed- rivers ACTIVITES HUMAINES soils Flux./proc Atmosphere T, light, deposits,

3 Issue 1: Fluxes and processes at the interfaces Issue 2: Structuring ecological processes Issue 3 : Quality and management of the lakes and their ressources (environmental drivers changes) ► biogeochemical hot spots ► upstream-downstream fluxes ► fluxes modelling Lac usages (pêche…) flux Bassin versant - affluents sols flux ATMOSPHERE T, lumière, dépôts ► measurements ► quality indicators ► helping managers Biodiversity Functions Structure 3 organisation levels ► role of biodiversity ► biological models ►productivity- trophic fluxes ►ecotoxicology 1-1. Global scientific context

4 2 – Operational issues PAST status Today status Surveys and data LEMANMESOTROPHIC (from1957) CIPEL BOURGETMESOTROPHIC (from 1990) CISALB ANNECY OLIGOTROPHIC (reference) (from 1980) SILA Annecy Bourget Léman  Re-oligotrophisation and climate vs fishing  Micropollutants (new or old)  Changes of land uses (practices..)  Gobal management (lake+watershed) Current questions (Ministery –Water Agency –Lake managers) * eutrophication : *control of P fluxes * re-oligotrophication  Taking into account the managers/stakeholders questions Lake uses: - fishing - water resources - recreational - ecological services

5 Head (1) Watershed group: Watershed, fluxes, sediments (5) RITOXE group: Fish Resources and Ecotoxicology of Lake Ecosystems (8) BIO-FEEL group: Biodiversity, Functions and Evolution of Lake Ecosystems (5) Environmental Research Observatory Technical group (University of Savoie(3 ) Chemistry lab(4) Biodiversity and Molecular Biology Group (5 ) Outdoor experimental devices (2) Sampling group(5) Secretariat and Accounting (2) Resource Center (1) Computing and database (2) Workshop (2) 45 full time 20 scientists 10PhD + post 3.1 The Unit and it’s scientific topics Thonon Chambéry

6 3.2 The Unit and it’s scientific topics Group WaterShed: Transferts and functionning at interfaces Main topic: The Watershed as a transfer system to the lakes ♦ Functional spatialization of watershed ♦ Fluxes from terrestrial to aquatic ecosystems Lac usages (pêche…) flux Bassin versant - affluents sols flux ATMOSPHERE T, lumière, dépôts Group » Biodiv- Funct »: Ecological processes and biological responses Main topic: « Functionning and regulation of trophic networks» ♦ Pelagic communities ♦ Functional role of biodiversity Group « Fish & Ecotox »: Environmental quality and Resources management Main topic: « Halieutic and stocking » ♦ Drivers of fish productivity (lakes and rivers) Main topic: « Algal and microbial ecotoxicology (biofilms,..) » ♦ Contamination dynamics and impacts (pesticides)

7 ACADEMIC (60 to 70 %) ► Producing generic knowledges (25 internat. papers/year + books) ► Building environmental Observatory: Alpine Lake Observatory ► Contributing to scientific networks RESULTS for SOCIO-ECONOMIC Instances and Public stakeholders (20%) ► Expert reports (Soils, Taxonomy), study reports, assessments,.. ► Decision-making assistance, developing partnerships (lakes, fishing, agriculture),producing documents ( technical guides, reports, …) RESULTS for education and training for research (<10%) ►University and engineer Schools. ►PhD formation ►PhD: ± 3/year 3.3 The Unit and it’s scientific topics

8 OBJECTIVES Organize data collection, their storage, their use and their accessibility Scrutinizing, understanding and modelling the trajectories and the ecological mechanisms controling the lake systems exposed to changes in anthropic and climatic pressures, at a 10 years time steps ». The Environmental Research Observatory « Alpine Lakes » (LTER) Le Bourget Mesotroph (re-oligotrophisation) Léman Mesotroph (re-oligotrophisation Annecy Oligotroph ±1950 ± 1980 ± 1990

9 Observatory Long term limnology Short and mid term processes Associated projects - Long term surveys - Physicochemical and biological processes controling water quality - Ecological trends - Consequences of global change - Small mountains lakes - Micropollutants ecodynamics > 10 years 1< < 10 years

10 Parameters - Physico-chemistry - Phytoplancton - Zooplancton - Bacterio & virioplankton - Chlorophyll - Primary production - Probes - Weather - Fish catches (annual) Information Systems – data base data Database Public access

11 Multiparameters Probes Perch O+ Zooplancton (net 2) Bacterioviroplancton Primary production Meteo data Flurorometric probe Fishes surveys Zooplancton (net 1) Phytoplancton Physico-chemistry Transparency (Secchi) General conditions Léman On paper ………………………………………………. Annecy On paper…………………………………………………………………. {…..on paper …………….} Bourget Historical data

ANNECY LEMAN BOURGET µg/l PO4 Increasing pollution Control of wastewater Long term dynamics of lakes: Eutrophication - Reoligotrophication

13 Phosphorus = limiting factor Bottom -up control Anneville et al., 2007 Journal of¨Plankton Research) Long term dynamics of lakes: Trophic network changes Abondance Temps PO 4 Effet Réponse Réponse Abondance Temps Réponse Abondance Temps Effet Abondance Temps Réponse Abondance Réponse Réponse Biovolume (ml.m -2 ) Catches (tons) Log (Biov+1) (µg.l -1 ) PO4 (µg/L) Lake Leman Top-Down control Changes in fish diversity (oligotrophy) Coregonus albula

14 LACS Thank you for attention