Saving the Saimaa charr
Scientists and fishing associations are working together to preserve an endangered variety of charr that has been isolated for thousands of years in Lake Saimaa, Finland’s largest lake system.Charr thrive best in cold waters, and were probably the first fish to swim in the new lakes and rivers that formed in Northern Europe at the end of the Ice Age 10,000 years ago. Like other members of the salmon family, many charr varieties migrate between their spawning watersand the northern seas, but charr in lake Saimaa live permanently in the lake’s deeper waters.
“The Saimaa charr is so different from the charr found in our other waters that it’s really worth preserving as a unique part of biodiversity – just like the Saimaa´s freshwater seals that live in the same lake system,” says fisheries scientist Nina Peuhkuri of the Finnish Game and Fisheries Research Institute (FGFRI).
According to Peuhkuri, overfishing and to eutrophication are probably the main reasons for the dramatic decline of the Saimaa charr over the last century, while climate warming represents an alarming new threat.
Only one naturally reproducing population of Saimaa charr still survives, in the waters of Kuolimo in the southwest corner of this vast labyrinthine lake system. The FGFRI maintains hatchery brood stocks of Saimaa charr descended from earlier generations of wild fish, but charr introduced from hatcheries into other parts of Saimaa over the last twenty years have not bred well enough to established self-sustaining populations.
Action urgently needed
The Ministry of Agriculture and Forestry, local fishery authorities and FGFRI have recently launched an action plan to save the Saimaa charr from extinction. Key measures include proposed controls over fishing in the waters where Saimaa charr still swim, such as new regulations on the meshsize of fishing nets and larger minimum size-limits for catches.
Local people understand the need for protective measures and are generally very willing to cooperate.
“Older fishermen in particular can remember how easy it used to be to catch charr compared to today, if you knew the right places.”
Peuhkuri believes that it should still be possible to save the last Saimaa charr in Kuolimo, and then build up stocks in other waters.
By Fran Weaver