Arcellaceans as Paleoenvironmental Indicators
Arcellaceans occur abundantly in Holocene lacustrine sediments and have been successfully used to reconstruct Pleistocene-Holocene lacustrine paleoenvironments. A relationship has been found between the distribution of arcellacean faunal assemblages and heavy metal pollutants (arsenic and mercury) in tailings in northeastern Ontario lakes, as with similar studies in Italy on acidic lakes polluted with copper and ammonium sulphates. Although ecological stresses on various arcellacean species have not been investigated thoroughly, a few individual species have been shown to vary in their gross morphology when under environmental duress. Members of such a sub-specific category are called a "strain".
Recent research of lakes in Canada and Italy has demonstrated the use of arcellaceans as an excellent indicator of pollution levels. Since the investigation of arcellacean distribution with regard to pollution levels is still in its infancy, previous investigations have been primarily of a reconnaissance nature, concerned with the determination of occurrences, and ranges in different environments. As a result of these studies, however, the importance of investigating the distribution of strains of different arcellacean species was realized. Different species appear to be influenced by the metal pollutants from mine tailings and they may indicate certain environmental parameters.