Background: Eighteenmile Creek was designated as an Area of Concern (AOC) in 1985 because water quality and bed sediments were contaminated by past industrial and municipal discharges, waste disposal, and pesticide usage. Five Beneficial Use Impairments (BUIs) were identified in the Eighteenmile Creek AOC, including BUI #3 - the degradation of fish and wildlife populations. The remedial action committee (RAC) for the Eighteenmile Creek AOC has identified the following removal criteria for this BUI:
· Fish and wildlife diversity, abundance, and condition are statistically similar to diversity, abundance, and condition of populations at non-AOC control sites; AND
· PCB levels in bottom-dwelling fish do not exceed the critical PCB tissue concentration for effects on fish (440 micrograms per kilogram wet weight)
Current knowledge of fish and wildlife populations in the Eighteenmile Creek AOC is largely based on a series of qualitative surveys in 2007 which compared fish and wildlife assemblages at a few locations in Eighteenmile Creek with those from several sites in a comparable reference stream, Oak Orchard Creek. The results indicated that fish communities were generally similar between the two creeks although some differences in relative abundance were noted. Furthermore, PCB concentrations in brown bullhead from Eighteemile Creek were approximately an order of magnitude higher than those from Oak Orchard Creek. Wildlife surveys indicated that bird and amphibian communities were similar between Eighteenmile Creek and Oak Orchard Creek although some differences were noted in mammal diversity and concerns remain about PCB risks to fish-eating mammals (e.g. mink).
There is little evidence, however, that elevated PCB concentrations have direct negative impacts on fish populations (Henry, 2015). Furthermore, the risks to fish-eating wildlife (birds and mammals) of consuming fish with elevated PCB concentrations are addressed elsewhere in the bird or animal deformities/reproductive problems BUI (BUI #5). Consequently, the RAC is considering eliminating the second removal criterion from the degradation of fish and wildlife populations BUI.
More recent and quantitative information is needed from more sites to effectively determine if “fish and wildlife diversity, abundance, and condition are statistically similar to diversity, abundance, and condition of populations at non-AOC control sites”. Such data collection should take place on both Eighteenmile Creek and Oak Orchard Creek using consistent sampling methods that are employed at a sufficient number of sites within each creek such that a statistical analysis can be conducted with appropriate statistical power. Such a study is already underway (2018) assessing mink populations but contemporary fish community data is needed to determine if fish communities differ statistically between the AOC and reference creek. Thus, the USGS-New York Water Science Center (NYWSC) and the New York State Department of Environmental Conservation (NYSDEC) will undertake a collaborative study to evaluate fish communities at the Eighteenmile Creek AOC and Oak Orchard Creek during 2019 and/or 2020.
Objective: The primary objective of this proposed study is to determine if fish population abundance and fish community structure differ significantly between the Eighteenmile Creek AOC and Oak Orchard Creek. This information, coupled with the results of the ongoing mink study, will then be used to reevaluate the degradation of fish and wildlife populations BUI.
Approach: The USGS and NYSDEC will survey and compare fish communities at 5-8 sites in the AOC and 5-8 sites in the portion of Oak Orchard Creek downstream of Waterport Dam using the following approach:
Fish surveys will be conducted in two different habitat types utilizing a different sampling methodology in each as follows. Surveys will be conducted at 3-5 sites in the lower portions of each study area that are navigable using boat electrofishing. Boat shocking methods will generally follow those outlined in “Standard methods for sampling North American freshwater fishes: Warmwater Fish in Large Standing Waters” (Miranda and Boxrucker, 2009). Specifically, daytime shocking (appropriate for moderately turbid waters) of nearshore habitats will be utilized at each site. Two subreaches will be shocked at each site (one at each shoreline of the stream channel) and shocking time at each subreach will be approximately 15 minutes. If high water levels permit boat operation further upstream than anticipated, the entire survey may be conducted using boat electrofishing.
If boat operation is not possible in the upper portion of each study reach, then surveys will be conducted at 1-3 sites in the upper portions of each study area that are wadable using backpack electrofishing of entire stream channels (or near shore reaches if flow/wading conditions prohibit blocking and sampling the entire channel width). As flow conditions permit, blocking seine nets will be placed completely across the channel at the upstream and downstream end of study reaches. Fish will be collected with a backpack electrofisher using a 3-pass depletion method, with three to four people netting all stunned fish. All captured fish will be identified to species, weighed, measured, and subsequently released back to the stream.
If flow/wading conditions are such that blocking seines cannot be extended across the channel, three replicate surveys (each composed of three electrofishing passes) will be conducted at each site in smaller near-shore sub-reaches, which will be blocked with a combination of three seines—one longitudinal seine (30 m) and perpendicular upper and lower blocking seines (7 m).
Data from boat and backpack electrofishing surveys will be standardized such that comparisons can be made between surveys on Eighteenmile Creek and Oak Orchard Creek. Electrofishing data will be standardized by shocking time to produce catch rates (catch per unit effort) expressed as fish per hour for each species and the entire fish community. These data will be analyzed using univariate and multivariate statistical approaches such as:
(a) linear mixed models using the nlme package (Pinheiro et al., 2017) in R (R Core Team, 2018) assessing differences in community abundance and proportion of different functional feeding groups.
(b) an index of community similarity (or dissimilarity) such as Bray-Curtis similarity to determine the degree of dissimilarity between the AOC and Oak Orchard Creek, and
(c) multivariate statistical methods such as non-metric multidimensional scaling ordinations and analysis of similarities (ANOSIM) using PRIMER-E v7 software (Clarke and Gorley, 2015) to determine if entire fish communities differ between the AOC and Oak Orchard Creek
References:
Clarke, K.R., Gorley, R.N., 2015. PRIMER v7: User manual/tutorial. PRIMER-E, Plymouth, UK
Henry, T., 2015. Ecotoxicology of polychlorinated biphenyls in fish—a critical review. Crit. Rev. Toxicol. 45, 643-661.
Miranda, L., Boxrucker, J., 2009. Warmwater fish in large standing waters, in: Bonar, S.A., Hubert, W.A., Willis, D.W. (Eds.), Standard methods for sampling North American freshwater fishes. American Fisheries Society, Bethesda, Maryland, pp. 29-42.
Pinheiro, J., Bates, D., DebRoy, S., Sarkar, D., R Core Team, 2017. nlme: Linear and Nonlinear Mixed Effects Models. R package version 3.1-131 ed
R Core Team, 2018. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria
Project Location by County
Niagara County, NY
