Predation of smelt on vendace larvae: experimental and field studies
2009
Haakana, H. | Huuskonen, H.
Lake Höytiäinen in eastern Finland has suffered from a prolonged vendace Coregonus albula (L.) recession during the last two decades. The present study examined the capacity of smelt Osmerus eperlanus (L.) to prey on vendace larvae as well as the diet of smelt in Lake Höytiäinen to reveal its possible predation on vendace larvae. The larvae were observed to be most vulnerable to smelt >100 mm (TL) predation at a total length of 13 mm. In Lake Höytiäinen, the diet of smelt was clearly dominated by zooplankton and no vendace larvae were found in the stomachs, probably due to small size of the smelt and low abundance of the larvae. Spawning time of smelt and larval period of coregonids overlap in spring and an observed decrease in feeding activity of smelt during spawning time may provide a temporal refuge against predation. Although smelt has been found to intensively predate on coregonid larvae in other lakes, it does not play an important role in maintaining the present low-density state of vendace in Lake Höytiäinen.
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