In Finland research on the Grey Seal (Halichoerus grypus) and the Ringed Seal (Phoca hispida botnica) is carried-out by the Finnish Game and Fisheries Research Institute in co-operation with the universities of Helsinki and Turku, the National Veterinary and Food Research Institute and the Finnish Institute of Marine Research. Co-operation with Estonian and Russian institutions with research on seals in the Gulf of Riga and in the eastern Gulf of Finland has been intensifying since 1992.
A working group, led by the University of Joensuu (Finland), is specialising in research on the Saimaa Ringed Seal (P.h. saimensis), a species living in the Saimaa Lake mosaic. This working group has extended its activities by starting research on the Ladoga Ringed Seal (P.h. ladogensis) together with the Karelian Scientific Centre, Petrozavodsk (Russia).
No really accurate data exists on the numbers of Ringed and Grey Seals in the Gulf of Finland, because research has been hindered by territorial prohibitions and limited access to vast sea areas. At present both species are totally protected. There are 200-300 Grey Seals in the Gulf. The number of Ringed Seals in the Gulf is possibly greater, but they occur mainly in the eastern parts of the Gulf and the stock is not known. To be able to protect the seals in the eastern Gulf, we must known the size of their populations and more about their behaviour and these investigations depend on good co-operation between Finnish and Russian researchers.
At the end of 1991, the carcasses of 150 Ringed Seals began to drift ashore on the islands in the eastern Gulf of Finland, mostly in Russia where the first specimens were discovered. In this sea area, the recorded mortalities of Ringed seals is generally less than 10% of this figure.
The death of this alarming number of seals had obviously occurred in Russian waters, somewhere in the vicinity of Great and Little Tyters. Of 150 carcasses only 12 were suitable for proper autopsy. The autopsies carried-out included the following tests:
| TESTS | RESULTS |
| Bacteriological: | No evidence of bacterial disease |
| Viral: | Serological tests for distemper, Herpes and Rabies were negative. Calici-titers were at ordinary levels. |
| Gamma ray: | Equivalent to levels after Chernobyl |
| Heavy metals: | No different to levels met with before incident |
| Organochlorine: | Dioxine, Furans and some Coplanar PCB congeners, but at same levels met with before incident. |
No evidence of bacterial or viral epidemy was revealed. The results of gamma ray and heavy metal measurements in muscle and in liver tissues respectively, and measurements to determine the organochlorine content of the blubber, did not show these pollutants to be at levels different from the seals still living in the same area. According to the results of the few autopsies possible, it seems that the seals died suddenly, by suffocation and/or drowning, and that the most probable cause of death was poisoning from some neurotoxic compound of unknown origin.
The investigation into the high mortality of Ringed Seals in the eastern Gulf of Finland at the end of 1991 was supported financially by WWF-Finland and carried-out in co- operation with the University of St. Petersburg.
To help us understand what is happening to the Ringed and Grey Seal populations in the eastern Gulf of Finland, field observations need to be more carefully co-ordinated. The UNESCO BFU expeditions, especially those in which sailing catamarans are used as transports, could play an active and useful role in seal studies, in particular through a proper link-up with the seal study group at the Department of Vertebrate Zoology, University of St. Petersburg.