University of BergenPublished: 06.09.2015 | Author: Stein Byrkjeland
GOLDEN ORFE FISH IN LAKE SKÅRSVATNET
In September, 1901, a load of golden orfe fish was transported from Preussen to Bergen for stocking of Nygårdspark. One of the originators of the project was the well known doctor Klaus Hanssen. Thirteen years later, Hansen was called to help. Would he please come to Øystese to assist the district doctor Peter Munch Søergaard in his attempt to combat tuberculosis in the village? Hanssen came - and had in his suitcase living "goldfish" from Nygårdsparken.
Among the goldfish there were golden orfe fish, in addition to crucian carp and perhaps also common carp. Lake Skårsvatnet was stocked with them. The population of golden orfe fish thrived for a long time in the lake. The fish lived close together and were of all different sizes. Throughout the 1980s people noticed that there were more of the dark, common type of orfe fish, which was a hybrid originating from the golden orfe fish. Increasingly, only larger golden orfe fish were observed, and people began to suspect that the golden orfe fish had ceased to reproduce in Lake Skårsvatnet.
A student at the University of Bergen started a master’s thesis on the lake, and he suggested that the likely reason for the change in the golden orfe fish population was the stickleback. The stickleback fish - introduced in the lake in 1967 – fed upon eggs and larvae. It became apparent that the larvae of the golden orfe fish were more attractive than the larvae of the darker type of orfe fish. As a consequence of these investigations, the golden orfe fish was afterwards hatched and nourished in places where they could be protected from the stickleback. When they grew large enough that the stickleback could no longer eat them, the orfe were released back into Lake Skårsvatnet. It is possible that these measures will save the recruitment of this particular fish stock.
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