Changes in 137Cs activity concentrations in various fish species and in lake water in Finnish Lapland

Aim of the study

The objective of this study was to study how the situation of the ¹³⁷Cs activity concentrations in lakes of Lapland has changed over time and what is the current situation. The ecological half-lives and the environmental factors that influence the long-term behaviour of ¹³⁷Cs were estimated. The correlations between fish and lake water were analysed and the concentrations factors were calculated.

Implementation

Lake Inari, which is the third largest lake in Finland covering 1 040 square kilometres, is situated in the North of Finnish Lapland. Lake Inari is an oligotrophic arctic lake with rich fish fauna, and important for freshwater fishing. The sampled species were pike (Esox lucius), perch (Perca fluviatilis), trout (Salmo trutta), whitefish (Coregonous lavaretus) and vendace (Coregonus albula). Lake Apukka is very different from Lake Inari. The lake is small, with an area 0,48 square kilometres and it is shallow and highly eutrophic. The fish fauna consist of pike, perch, roach and burbot (Lota lota). Lake Apukka is situated in the Northern Finland close to Arctic Circle.

Fish was sampled and measured regularly from Lake Inari between 1963 - 1970 and 1986 - 2007. The fish samples were collected from Lake Apukka in 1982 - 2007. The water samples were taken from 1988 until 2007. ¹³⁷Cs was measured with gamma spectrometry.

Dissemination and exploitation of the results

The results are published in the Proceedings of the Regular Meeting of the Nordic Society for Radiation Protection in 2008. A press release is issued in summer 2008.

Collaborators

None outside STUK

Timetable

2008

Responsible scientist

Jarkko Ylipieti

Page updated 15/05/2009