Evaluation of the trophic types of several Alaskan lakes by assessment of the benthic fauna

Abstract

Public Law 92-500 (1972) which amends the Federal Water Pollution Control Act contains Section No. 314 entitled Clean Lakes which gives each state a mandate to "... prepare or establish ... an identification and classification according to eutrophic condition of all publicly owned fresh water lakes in such state . . . ." This mandate presents an awesome task to the State of Alaska which contains millions of lakes which must be evaluated according to the interpretation of this law. It was the intent of this project to examine the application of a biological index of eutrophy to several Alaskan lakes by comparing benthic macroinvertebrate faunal distribution to selected chemical and physical indices of trophic state. The investigator chose to consider "indicator organisms" as the focus of the study and found this concept to be interestingly difficult to apply.