pondělí 25. ledna 2016
Monitoring the freshwater pearl mussels‘ population and their biotope
The monitoring results show that in the last five years the population of freshwater pearl mussels has declined by one half. This progress is not surprising; it is caused mainly by a high age average of the population, where most individuals are close to the maximum age. But what was encouraging was the finding of juveniles coming from Saxon rearing which confirmed its efficiency. Therefore it is recommended to continue in semi-natural rearing which helps pearl mussels overcome the critical period.
The biological indication method was developed to check the quality of a biotope. Here, juvenile pearl mussels are placed into the stream in special panels and their mortality and growth are measured. Last year’s tests have shown lower mortality and bigger growth of pearl mussels in places where we take care of the biotope, e.g. by maintaining food brooks or meadow vegetation, than in other parts of the streams.
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