A comparative study of algal flora in five marshes.

Abstract

Freshwater marshes are an important contributor to the ecological balance of the Great Lakes. They are the interface between terrestrial and aquatic systems and provide a productive habitat for many different species. It is important to assess the water quality in marshes for indications of change in organic and physical composition. Water quality testing attempts to indicate the health of an aquatic environment over a wide variety of variables. Chemical tests are useful for obtaining an isolated ""snapshot"" of the water quality such as temperature, water hardness, pH, and nutrient conditions. Differences in these variables are often manifested in the diversity and abundance of aquatic inhabitants. Tested independently however, these variables do not address the dynamic nature of their interaction within an ecosystem over time. Algae are often a more reliable indicator of how physical and chemical variables act synergistically within an aquatic system. Assessment of water quality through monitoring of algal communities has proven to be ecologically significant. The algal community is forced to adapt and respond quickly to seasonal and diumal fluctuations in aquatic conditions as well as anthropogenic factors because integration of many factors affects its relative abundance and diversity. Due to the short generation time of algae and their sensitivity to toxicants, monitoring algae in polluted environments can be especially effective. Certain algal species have emerged as consistent pollution indicators. ""The importance of the effects of toxicants on phytoplankton should not be underestimated since this group forms the most important group of primary producers in aquatic food webs.""(Sicko-Goad and Stoermer l988). In this experiment, epiphytic algal communities from five different marsh regions were assessed to determine the numerical variance and distribution of the algal flora between sites. Data collected from these sites were analyzed to determine if there were significant differences in algal diversity and abundance between the sites. The histories of the sites were taken into consideration with regard to human and industrial contamination. Field observations of human development and previously recorded data provided baseline but incomplete information on the relative contamination of each site. We hypothesized that the sites with established records of contamination would show signfiicant variation among algal communities, compared to sites considered prime.