Freshwater pearl mussel as indicators of Swedish streams - a comparison between freshwater pearl mussel and biological quality elements
The freshwater pearl mussel (Margaritifera margaritifera) is a large freshwater mussel. Because of its sensitivity to human impact, such as eutrophication, acidification and alterations of hydromorphology, the species is considered as a robust indicator of stream water quality and biodiversity. Moreover, due to the species complex life cycle, including a larval stage on the gills of salmon and trout, and sensitivity of early life stages, regeneration is often used as an indicator. The freshwater pearl mussel is also used in the expert judgement of status classification of benthic invertebrates according to the European Water Framework Directive.
The purpose of this study was to gain a deeper understanding of the freshwater pearl mussel as an indicator for Swedish streams. It was made with two types of
association analyses. Regeneration of freshwater pearl mussel populations was compared with several indices and parameters of the biological quality elements benthic fauna, diatoms and fish. Then, values and classes for indices and parameters were compared across water bodies where freshwater pearl mussels were recorded as being present or not present. The association analyses were made with appropriate statistical methods and the results were considered significant for a p-value