The Use of Artificial Substrates in Pollution Surveys

Abstract

Artificial substrates were constructed from pressed Masonite board and suspended in the Minnesota and Mississippi Rivers during the summer of 1965. The benthos recovered from the Mississippi River substrates reaffirmed the zones of water quality defined by results from conventional bottom sampling techniques, and analysis of chlorophyll-a indicated a progressive increase in periphyton crop below the major contributors of organic pollution. The numbers and kinds of benthic animals gathered from the Minnesota River substrates differed from results obtained from conventional bottom sampling methods, and suggest that the factor limiting river biota is a lack of suitable natural habitats rather than chemical quality.