Seals in the changing environment

Warming winter temperatures worsen the breeding conditions for the Baltic Sea ringed seal. Photo: Mervi Kunnasranta

In the 1960's and 1970's, very high concentrations of heavy metals and organochlorine compounds were found in the tissues of the Baltic Sea seals. The high PCB and DDT concentrations lead to a prohibition of these substances. There is some evidence that high concentrations of organochlorine compounds can have deteriorating effects especially on seals' reproductive health.

Since then the concentrations of environmental toxins have decreased, although they are still many times higher than in comparable species in less contaminated areas. With the decreasing concentrations, the seals' reproductive health has improved. The reproductive health of female grey seals is nowadays normal. On the other hand, 20% of female ringed seals still suffer from pathological changes in uterus.

Seals and the climate change

Both the grey seal and the ringed seal breed primarily on ice. The climate change will have an impact on the breeding conditions for both of the species. The effects of the warming of the climate for ringed seals can be significant, because their breeding is strongly influenced by ice and snow cover. Grey seals can probably adjust fairly well also to ice-free winters.

Seven seal sanctuaries

In 2001, seven seal sanctuaries were established on sea areas owned by the Government. The Finnish Game and Fisheries Research Institute in 2003 and 2006 surveyed professional fishermen's views about seal conservation areas.

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