The most important research activities in 1994-98 are directed to the effects of intensive fishing (food web manipulation) on fish assemblages and water quality in eutrophicated lakes Vesijärvi, Hiidenvesi and Tuusulanjärvi. Studies concerning fish stock assessment methods in the same lakes also form an important part of research activities. Assessment methods include e.g. hydroacoustics, virtual population analysis and catch depletion methods. Research activities include studies concerning the effects of global warming on fishes, fish recruitment and fisheries. The impacts of environmental changes and fishing on fish populations are studied especially in the coastal waters of the Baltic Sea and in lakes of northern Finland. Further projects are directed to studies concerning the effects of the European Union membership on the Finnish fishing industry, fish ecology, parasitology and fisheries management in subarctic lakes and optimatisation of fisheries of pikeperch and whitefish utilizing modern decision analysis methods. Several studies are cunducted in co-operation with other Finnish and foreign universities and Finnish game and fisheries research institute.
The majority of the research activity in limnology is directed to a large comprehensive project to study the dynamics of the lake ecosystem. Project includes studies in nutrient dynamics (especially phosphorus and silica) between sediment and water, studies concerning dynamics of plankton communities and relations between plankton and fish. Further subprojects are concerning the role of macrophyte zone in lake, lake history description with the paleolimnological methods (diatoms and zooplankton remains) and finally the evaluation of external loads to the lake. The main aim of those studies is to explain the major factors controlling the status of large eutrophicated lake (Hiidenvesi). The program is a continuation to the biomanipulation project of the lake Vesijärvi, which was initiated by the scientists of the department. The new object lake has different structure and problems in nutrient – plankton – predator – fish –system than in Lake Vesijärvi making new problems to lake restoration.
The other research objectives are directed to methods of the biological river quality assessment and to fresh water red algae as a European wide threatened group, which still has in Finland high diversity.
Further projects are connected to dynamics of the methylation processes of mercury in humic water sediments and into nutrient competition between bacteria and phytoplankton in brackish water pelagial ecosystems.
Environmental science and policy
The Section on environmental science and policy focuses on multidiciplinary approaches regarding the environment. Similar groups exist in other universities and institutes under headings such as industrial ecology, environmental systems analysis, and human ecology. Issues at local, regional and global scales are included dealing with the environment and development. The main interest is in long-term issues both in historical analyses and in futures research. The interest is in land use, traffic, industrial systems, and consumption patterns.
A particular line of research - heavy metals in the environment - carries a long tradition within the Section on environmental science and policy. The largest on-going project deals with the fluxes of heavy metals and nutrients in the forest industrial system within Finland. In 1998, contracted by the Rector of the University of Helsinki, an analysis was prepared at the Section on environmental science and policy on how to reduce the harmful environmental impacts of the university itself.
The Section on environmental science and policy is in the middle of a strong change. The research resources have increased manyfold from 1997 to 1999. Strategic work of re-defining the reasearch focus has started with the aim of directing the Section towards multidiciplinary projects. The views from both science and the human dimension are included.