The Function and Management of Aquatic Ecosystems in the Changing Environment

This project is a apart of a large AQUDIGM consortium. The consortium studies the validity of strong paradigms on the functioning and management of lake ecosystems. The objectives of this subproject are to evaluate the paradigms on the important role of oxygen deficits in regulating internal phosphorus (P) loading and the effectiveness of artificial aeration as a management tool. Additionally, in the other subprojects of the consortium the barriers of possible paradigm shifts (leader prof. Ilmo Massa) and consequences for management and decision-making in the future (leader adjunct prof . Petri Tapio) are studied. The consortium forms a new interdisciplinary research group, which adds mutual understanding within different fields of research. The facts forming the footing of the current paradigms are determined and information needed for paradigm shifts is identified by studying the origin and strength of the paradigms with analysis on existing documents and interviews. Updated lake data are collected and the internal P loading from anoxic areas is estimated for a large number of lakes (hypolimnetic P accumulation) and compared with water quality parameters and independently estimated total internal P loading (retention models and new sediment data). The conditions facilitating successful aeration are identified by meta-analysis of data from aerated lakes and by detailed field studies in an ongoing aeration project. The possible changes in management strategies are studied with expert view surveys and stakeholder workshops based on state-of-the-art knowledge and with the new results from the lake studies. Information on the barriers of paradigm shifts is used. Scenarios on the consequences of new management strategies are produced.