Use ofEnteromorpha intestinalis (Chlorophyceae) for active biomonitoring of heavy metals in the weser estuary

The present study was planned to assess the validity ofEnteromorpha intestinalis for an active biomonitoring of heavy metals in the Weser estuary. Exposure of cultured algae (active biomonitoring) was carried out in 1987 and 1988, simultaneouslyEnteromorpha spp. was collected from the banks (passive monitoring) in the estuary. Cd, Pb, Ni, Zn and Cu contents of exposed algae were higher than the metal content of collected algae. Metal contents of both collected and field algae varied significantly over space and time. Bioconcentration factors and results of linear regression analysis indicate, that the bioavailability of Cu and Ni varies with regard to the sampling location but cannot be calculated from heavy metal concentration in the water. Due to the different metal and species specific bioavailability, we want to stress the need to monitor contamination of organisms directly. An active biomonitoring usingE. intestinalis will establish a rationale to compare contamination of different estuaries.