Estimating Acute and Chronic Toxicity of Waters from the Rochester Embayment Area of Concern Using Two Plankton Species

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Background Discharges from non-point sources, municipal and industrial point sources, and combined sewage overflows over the last century resulted in elevated levels of heavy metals, conventional pollutants, phosphorus, and toxic organic contaminants in water and sediments of the Lower Genesee River and Rochester Embayment. As a result, the zooplankton and phytoplankton or “plankton” communitie...

Background

Discharges from non-point sources, municipal and industrial point sources, and combined sewage overflows over the last century resulted in elevated levels of heavy metals, conventional pollutants, phosphorus, and toxic organic contaminants in water and sediments of the Lower Genesee River and Rochester Embayment. As a result, the zooplankton and phytoplankton or “plankton” communities were designated as one of fourteen Beneficial Use Impairments (BUI); i.e., the resource was either impaired or in need of assessment in the Rochester Embayment Area of Concern (AOC).

The Rochester Embayment Remedial Action Committee (RAC) was formed by the New York State Department of Environmental Conservation (NYSDEC) and the Monroe County Department of Health, Bureau of Water Quality Planning to continually assess and marshal key remediation efforts. A technical committee of the RAC developed a Remedial Action Plan (RAP) with primary goals to "restore, protect, and maintain the chemical, physical, and biological integrity of the Lower Genesee River and Rochester Embayment Area of Concern in accordance with the Great Lakes Water Quality Agreement and other agency laws, regulations, and policies."

Over the past 30 years, the RAC has helped initiate projects and programs to reduce or prevent several point and nonpoint pollution sources, combined sewer overflows, and mercury pollution as well as efforts to educate residents and businesses on methods to prevent pollution in the Lower Genesee River and Rochester Embayment. These changes, and recent decreases in industrial activity and wastewater discharges, may have improved water quality and eliminated major impediments to native plankton species populations and natural assemblages in the Rochester Embayment AOC.  Thus, the BUI for plankton may now be outdated.

The RAP established specific criteria in the Rochester Embayment AOC for removing (restoring and protecting) the "Degradation of Phytoplankton and Zooplankton Populations" BUI. These criteria have been modified since their inception and most currently state: (1) "AOC plankton bioassays confirm that toxicity in ambient waters (i.e., no growth inhibition) is not significantly higher than comparable non-AOC controls", or (2) "Ambient water samples of AOC waters comparable to non-AOC control sites cause no toxicity to zooplankton and phytoplankton".

Objectives

The objective of this study was to determine if the phytoplankton and zooplankton beneficial use is impaired, or not impaired, in parts, or all of the Rochester Embayment AOC. Plankton toxicity data were used, specifically, to test whether waters in this AOC meet established criteria for delisting the plankton BUI.

Approach

This study generated toxicity data needed to test hypotheses that (1) waters at all sample locations in the AOC are not toxic to plankton and (2) the toxicity of waters at all sample locations in the AOC are no more toxic to plankton than are waters from non AOC control reaches (in The Genesee River Embayment.) Toxicity of waters to plankton from all study sites were quantified by the (a) growth of the green algae species, Pseudokirchneriella subcapitata and (b) reproductive capacity (and survival) of Ceriodaphnia dubia using standard U.S. Environmental Protection Agency (USEPA) guidelines. Statistical analyses that test both hypotheses were used to determine if waters within the Rochester Embayment AOC appear to meet the second criterion for delisting the plankton BUI.

Findings

In general, test results showed that the toxicity of waters from AOC sites was not significantly higher than at comparable non-AOC reference sites. Survival and reproduction of C. dubia did not differ significantly between site types, systems, or months. The growth of P. subcapitata did not differ between site types, but differed among systems and months. All results indicate that waters from AOC sites were no more toxic to both plankton species than were the waters from reference sites.

Products

 

Baldigo, B. P., B. T. Duffy, A. J. Smith and S. D. George. In press (2016). Toxicity of waters from the Rochester Embayment Area of Concern to the plankton species Pseudokirchneriella subcapitata and Ceriodaphnia dubia. Journal of Great Lakes Research. doi:10.1016/j.jglr.2015.12.007

Project
Location by County

Monroe County, NY