Waiting for frosts and ice: the young freshwater pearl mussels have to survive their first winter in river water
The youngs performed well in the summer, says Professor Jouni Taskinen from the Ģֱ.
Over the summer, they grew from 2 millimeters to 4-5 millimeters in size. Tiny mussels live now in protective hole plates near the bottom of the river. Over the summer, researchers visited regularly to clean hole plates. The silting of the waters and the inhibition of the flow of water in the dregs undermine the living conditions of the mussels.
The prognosis for babies is good when it comes to surviving the winter. There may be a threat of a kind of slush ice which forms when temperature of running water goes under zero degrees.
“In some previous experiments in central Europe youngs have done well, so we think they'll be fine here too. But we have the longer winter and ice. In special conditions, ice formation in river can start from the bottom. That's when the “home” of mussels can freeze”, explains Taskinen.
The grown-up mussels are prepared for this by burrowing deep inside the dregs for winter, but in this research project the hole plates cannot be buried that deep .
“For baby mussels the best way to be prepared for winter is to grow as big as possible before winter. That's how they get collected reserve food for the long winter. During winter time, especially under the ice deck, there is little phytoplankton production, leaving edibles low”, Taskinen says.
The study is part of the , a major inland conservation project coordinated by the Metsähallitus. At the Konnevesi research station researchers are e.g. monitoring how young mussels returned to nature develop compared to mussels growing in station conditions.
For further information:
Jouni Taskinen, jouni.k.taskinen@jyu.fi, tel. +358 40 355 8094
The Faculty of Mathematics and Science
Communications Specialist Tanja Heikkinen, tanja.s.heikkinen@jyu.fi, +358 50 472 1162
/science/en
jyuscience jyuscience jyuscience