Abstract

 The harbor at Erie, Pennsylvania has been designated as the 43rd Great Lakes Area of Concern. The impaired beneficial uses include the high incidence of fish tumors and restrictions on dredging. The goal of the current study was to ascertain the level of contamination in harbor sediments using the USEPA's GLNPO Sediment Triad Approach (a coordinated study of benthic community structure, sediment toxicity, and chemical analyses). Specific activities included the analysis of Ponar grab samples and core samples.
  Methods were selected from the Great Lakes Dredged Material Testing & Evaluation Manual, SW-846 and the USACE Inland Testing Manual. The draft method for measurement of acid volatile sulfides and simultaneously extracted metals was used to estimate bioavailability of metals. Analysis of benthic macroinvertebrate community structure was in accordance with the GLNPO's ARCS Assessment Guidance Document. Samples were collected over a 10 day period in June 2000.
  The sediments of Presque Isle Bay are moderately to severely contaminated with heavy metals, polycyclic aromatic hydrocarbons (PAHs), and oil & grease. The presence of these contaminants, along with very fine particle grain size, results in a relatively inhospitable environment for sediment-dwelling organisms. The benthic community is clearly dominated by pollution-tolerant organisms, and is relatively lacking sensitive species such as mayflies and caddisflies.
  In vitro bioassays yielded mixed results. There was essentially no toxicity with the amphipod and midge larvae. However, D. magna demonstrated diminished reproductive success.
The impairment of Presque Isle Bay sediments is modest only when compared with other Great Lakes sites having dramatically higher levels of contaminants. Nonetheless, water quality of the Bay appears to be satisfactory, and the fishery appears to be robust (although there is continued concern for the incidence of tumors in bottom-dwelling fish).
  Management alternatives include active actions such as dredging or capping, but a more practical approach is to diminish the release of contaminants from the watershed. Eventually, natural transport of cleaner sediments into the Bay will cover the existing sediments. There is no evidence that sediments currently moving down the Bay's tributaries are less contaminated that those in the Bay, but it is hoped that aggressive efforts within the community could result in this desirable environmental goal.