Use of sequential sampling of amphipod abundance to classify the biotic integrity of acid-sensitive lakes

Abstract

A sequential sampling program is described for ubiquitous, cost-effective biomonitoring of the effects of lake acidification. Spring densities of the littoral amphipod Hyalella azteca are quantitatively sorted into 5 abundance categories. Stratification of proportional densities per unit macrophyte biomass in relation to the aqueous total phosphorus concentration is an essential step in the a priori definition of decision criteria. Density rankings were related to lake acidity and to detailed lake-specific information on patterns of Hyalella life history and acid tolerance. Incorporation of Hyalella abundance as a potential metric for the assessment of the biological integrity of acid-sensitive waters is recommended. The temporal integration of transient changes in spring meltwater chemistry is an important rationale for the development of such biomonitoring procedures.