Empirical Hypothesis to Explain the Restricted Distribution of Hyalella azteca (Amphipoda) in Anthropogenically Acidified Lakes

Publisher Website
Google Scholar
Abstract
A simple and speculative model is proposed to explain the restricted distribution of Hyallela azteca (Amphipoda) within acidified Ontaria [Canada] lakes. The model integrates field chemical and ecological data with results from laboratory toxicological experiments. Frequent spring depressions of pH to below 5.0, measured in the littoral zone of Plastic Lake during 1982, were predicted to cause a mortality of 35.2% to a theoretically constructed amphipod population. A time trend simulation suggested that population decline of H. azteca in similar anthropogenically acidified lakes could be caused by such direct mortality due to short-term pH fluctuations. Assumptions and factors not considered by the model which could exacerbate or mitigate the effects of acidic snowmelt to H. azteca are discussed.