Eighteenmile Creek Remedial Action Plan Area of Concern Planktonic Community Study

Abstract

The preponderance of evidence suggests that the plankton community of Eighteenmile Creek is not impacted by contaminants. The summer zooplankton community of Eighteenmile Creek has a similar or higher species richness, a remarkably similar measure of dominance (i.e., evenness) and in July, a comparable abundance to the relatively pollution-free reference sites at Yanty, Buttonwood, and Salmon Creeks. Similarly in June, zooplankton abundance, species richness, and evenness for Eighteenmile Creek were between the values for the reference sites at Yanty Creek and Buttonwood and Salmon Creeks. Further support of this analogous comparison is provided by the phytoplankton data. Species richness, evenness, abundance, and species composition of phytoplankton are similar for Eighteenmile Creek, the unpolluted reference site at Yanty Creek, and for the AOC at the Oswego River and Harbor for the months of June and August. Seasonal changes, sample timing, and local sampling site characteristics and location can be challenging to data assessment and reference site comparison; however, substantially similar and healthy communities indicate no overall degradation or impairment in the planktonic populations in the Eighteenmile Creek AOC.