The higher temperature increases the risk of grayling larvae dying, but primarily it can accelerate their development.
This creates an imbalance with their food, zooplankton, which is dependent on sunlight for its development. During the winter, when sunlight is scarce, there is not as much plankton and the grayling larvae that have just hatched risk starving to death.
As if that were not enough, they also compete for food with other fish, whitefish and pike – which also eat grayling larvae.
A solution to the problem can, according to the experts that P4 has spoken to, be to increase fishing for whitefish and reduce fishing for grayling.
