The use of macroinvertebrates as indicators of health status in cranberry bogs and associated wetlands in coastal Massachusetts

White, Erin Lynn
Jon Atwood, PhD
Department of Environmental Studies
Macroinvertebrates may be used as indicator species to determine the health of an aquatic community, and their monitoring is important to the conservation of biodiversity in aquatic environments. The purpose of my study was to characterize aquatic macroinvertebrate assemblages in active cranberry bogs and compare them with those of associated natural wetlands and abandoned cranberry bogs. Field data were collected during three sampling sessions in Manomet and Cedarville, Massachusetts, in April, June, and September of 2002. Study sites included a total of five natural wetlands (three large and two small), five active cranberry bogs (three of which were organic), and four abandoned cranberry bogs. Abiotic data including depth, temperature, pH and dissolved oxygen (DO) were collected to accompany the biotic data. There was evidence to suggest a difference in macroinvertebrate diversity among the five habitat types, with large natural wetlands scoring the lowest family biotic index, but most habitats may be characterized as somewhat impaired. Natural wetland habitat types had significantly higher pH values than other areas. Dissolved oxygen was found to have a significant inverse relationship with temperature in the habitats studied, and there was evidence to suggest that habitats with higher abundance of open water have greater DO. Both organic cranberry bogs and those with a recent history of pesticide use showed some degree of impairment, but results suggest invertebrate recovery. Management suggestions for the maintenance of macroinvertebrate biodiversity in cranberry bogs include: maintaining water levels in ditches during dry periods, maintaining open water areas while allowing emergent plants to colonize ditches, and conducting seasonal monitoring of aquatic macroinvertebrate assemblages and abiotic water parameters to detect any change in water quality.

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