The estimated seal count for grey seals living in the Baltic Sea was slightly more than 22,300 in 2008. This estimation is based on annual spring grey seal counts carried out by Sweden, Finland, Russia and Estonia. The Finnish Game and Fisheries Research Institute is responsible for counts carried out in Finnish sea waters.
The grey seal count of the Baltic sea has grown over the past several years. The count for 2008, however, was only slightly higher than for the preceding year (22,000). During the spring season, the largest concentration of seals can still be found near the northern edge of the Baltic Sea main basin in the central Swedish archipelago, and the south-western archipelago of Finland. During the other seasons, however, grey seal distribution may look quite different.
The spring weather conditions in 2008 were excellent for seal counting. The counts were done through aerial photography, with flights encompassing Finland and Sweden and, for the first time, Estonia. In Russia seals are still counted from boats. This year the largest grey seal populations were sighted in Finnish sea waters and the next largest populations in Swedish sea waters, exactly the opposite of last year’s sightings. The changes in sightings can partly be explained by the fact that grey seals tend to travel considerable distances.
The grey seal counts are done within two weeks in late May and early June in the main distribution area for the species. At this time the grey seals are moulting and thus lie visibly on rocks and the last ice floes in their greatest numbers. The counting period is short to minimize multiple counts of the same individuals who may move from one place to another. The count is smaller than the true size of the stock, since some seals are always in the water out of reach of the count, no matter what the weather conditions may be. The counts in early summer will take into account a large proportion of the number of individuals, and as the count is repeated at the same time year after year, the results give a good picture of the development of the stock.
Sightings of grey seals in late May and early June 2008 according to sea area and country
(Source: Baltic Sea international grey seal counting team 2008).
the Finnish Game and Fisheries Research Institute:Scientist Mervi Kunnasranta,
tel. +358 (0) 40 532 9496
Research manager Vesa Ruusila,
tel. +358 (0) 40 840 6877