The application of a Biopollution Index in German Baltic estuarine and lagoon waters

Abstract

This paper assesses the status of three German Baltic estuarine and lagoon waters with respect to invasive species (macrozoobenthos) andtheir impact. A Biological Pollution Index was applied and evaluated. Overall 130 macrozoobenthic species were identified, 17 of whichwere aquatic alien species. The Szczecin Lagoon had the highest number of invasive species (13). Most species were of Pontocaspian origin;inland waterways are likely to play a significant role in their migration. According to the Biological Pollution Index Level (BPL) this lagoonwas ‘moderately influenced’ by invasive species. Warnow Estuary had 11 invasive species; their origin noted generally from North-America,suggesting shipping traffic as the major distribution vector; invasive species had the same BPL as in the Szczecin Lagoon. In theDarß-Zingst-Bodden-Chain only 6 invasive species were observed, having the highest relative abundance (9–71%). Furthermore, this areahad the highest BPL of all three areas, i.e. a strong negative impact. The BPL required a lot of data (including historical) and some ratingswere subjective and comparisons with other areas assessed were difficult and often impossible. Due to these limitations, it is suggested thatthe BPL should only be used with restrictions as a universal assessment tool for invasive species in the estuarine and lagoon waters of theBaltic Sea.

Keywords

• Baltic Sea
• invasive species
• biopollution index level