Bioaccumulation of heavy metals by aquatic macro-invertebrates of different feeding guilds: a review

The available literature on heavy metal bioaccumulation by freshwater macro -invertebrates has been analysed. A very uneven data distribution was found . Ephemeroptera and Diptera are the most commonly investigated orders of in sect larvae, whilst many orders are not represented at all. The collector-g atherer and predator feeding guilds are more frequently investigated than o ther guilds. Furthermore, Zn, Cu, Pb and Cd are the most intensively resear ched heavy metals, and only infrequent investigations of other metals are d ocumented. Relationships between metal concentrations in the animals and le vels in sediments and waters were determined from the pooled data for three feeding guilds. No one relationship represents how each metal interacts wi thin the feeding guilds. Each of the four metals (Zn, Cu, Pb and Cd) displa ys a unique relationship between metal concentrations in sediments or water s with those in individual feeding guilds of macro-invertebrates, indicatin g the relative importance of different sources of metals to the different f eeding types. Biomagnification of Zn, Cu, Pb and Cd has been demonstrated n ot to occur between these guilds. (C) 1999 Elsevier Science B.V. All rights reserved.