Impacts of Terrestrial Organic Matter Loading on Lake Food Webs and Human Health

- Challenges for Environmental Regulation (TERLA consortium)

Project funded by Academy of Finland, AKVA-program in 2012-2016

Boreal aquatic ecosystems with forested and peatland catchments naturally receive high loads of terrestrial organic matter. Moreover, catchment management of the carbon rich soils, especially forestry operations and peat mining, may greatly add the load of organic humic matter to their recipients. To some extent bacteria and microbial food chain of the lakes are able to utilize terrestrial organic carbon.

Bacteria, however, are poor-quality food for the upper trophic levels. The organic matter loading also impacts on phytoplankton, which produces beneficial polyunsaturated fatty acids. All consumers in the food web including humans are dependent on these fatty acids. On the other hand, organic matter loading often transport mercury to aquatic ecosystems and in anoxic conditions it is easily methylated to toxic methyl-mercury.

The objectives of the TERLA research consortium are to examine the impacts caused by terrestrial organic matter on lake food webs and human health and provide science-based knowledge for evaluating and improving the regulation on organic carbon loading. The approach is multidisciplinary combining expertise in limnology, ecotoxicology, forest sciences, public health and environmental law.

The research methods include modeling of terrestrial organic carbon loading, analyses of existing data bases, experimental and field studies on selected food-web variables of lakes, from terrestrial detritus, phytoplankton and bacteria, to fish and fish-eating people as well as a legal dogmatic approach.

The project is a combination of three sub-projects:

  • Lake ecosystem responses: Docent Paula Kankaala, Dr. Ursula Strandberg, Dr. Sami Taipale and Dr. Jarkko Akkanen. University of Eastern Finland, Department of Biology
    • Modeling of organic carbon loading: Dr. Sirpa Piirainen and Dr. Marjo Palviainen, Natural Resouces Institute Finland and
    • Phytoplankton database analyses: Docent Marko Järvinen and Dr. Kristiina Vuorio, Finnish Environment Institute
  • Human health impacts: Prof. Tomi-Pekka Tuomainen and Dr Tarja Nurmi, University of Eastern Finland, Institute of Public Health and Clinical Nutrition
  • Environmental regulation: Docent Ismo Pölönen and MSci Lea Halonen, University of Eastern Finland, Department of Law