Oceanographic Applications to Eutrophication in Regions of Restricted Exchange

The Oceanographic Applications to Eutrophication in Regions of Restricted Exchange (OAERRE) project aims to understand the physical, biogeochemical and biological processes, and their interactions, involved in eutrophication in coastal marine Regions of Restricted Exchange (RREs), especially lagoons and fjords. The scientific issues addressed include the controls on horizontal and vertical exchange in RREs and the response of coastal ecosystems to nutrient enrichment. OAERRE is a collaboration amongst physical, chemical and biological oceanographers, and coastal resource managers, with intensive studies relating to eutrophication at sites that exemplify a range of hydrographic and enrichment conditions. OAERRE's objectives are: (1) Observations of the physics of vertical and open boundary exchange in RREs, leading to improved parameterisation of these processes in research and simplified models. (2) Study of the phytoplankton and pelagic micro-heterotrophs responsible for production and decomposition of organic material, and of sedimentation, benthic processes and benthic-pelagic coupling, in RREs, with the results expressed as basin-scale parameters. (3) Construction of closed budgets and coupled physical-biological research models for nutrient (especially nitrogen) and organic carbon cycling in RREs, allowing tests of hypotheses about biogeochemistry, water quality and the balance of organisms. (4) Construction of simplified 'screening' models for the definition, assessment and prediction of eutrophication, involving collaboration with 'end-users', and the use of these models to analyse the costs and benefits of amelioration scenarios. Twelve partners were involved and six sites: Kongsfjord (Svalbard), Gullmaren (Skagerak), Himmerfjärden (Baltic), Firth of Clyde (Scotland), Golfe de Fos (French Mediterranean) and the Ria Formosa (Algarve) were investigated.