Anthropogenic alterations of the Raritan River, NJ from pre-European settlement through the presentMargaret Christie* (Presenting Author), Jennifer Clear, Jennifer Walker, Timothy Shaw, D. Reide Corbett, Mihaela Enache, Nina Desianti,

Marina Potapova, Daria Nikitina, Francisco Artigas, Ben Horton*margaret.christie@rutgers.edu

1. ABSTRACT

4. CHRONOLOGY

ReferencesHilgartner, W., & Brush, G. (2006). Prehistoric habitat stability and post-settlement habitat change in a Chesapeake Bay ) freshwater tidal wetland, USA. The Holocene, 479-494.Potapova, M., & Charles, D. (2007). Diatom metrics for monitoring eutrophication in rivers of the United States. Ecological Indicators, 48-70.Potapova, M., Desianti, N., & Velinsky, D. (2015). Barnegat Bay Nutrient Inference Model. Philadelphia, PA: Academy of Natural Sciences of Drexel University.Spaulding, S, and Edlund, M . (2009). Caloneis. In Diatoms of North America. Retrieved May 31, 2018, from https://diatoms.org/genera/caloneis

3. POLLUTION IMPACT RECONSTRUCTION

6. ACKNOWLEDGEMENTS

Thank you to the Mushett Family Foundation for providing funding for thisproject

By the start of the 18th Century, the Raritan River began to suffer impairments due to developmentpressures and anthropogenic activities. Despite this, anthropogenic activities for the 20th and 21stcenturies have not been quantified. Pollen and diatom assemblages contained in wetland sedimentsprovide an archive of habitat alteration in the Raritan River. Sediment cores collected from these tidalwetlands expand our understanding of habitat and water quality prior to European settlement,allowing establishment of base-line conditions.

Here, we present results from an investigation of changing habitat, nutrient conditions, and waterquality over the past 500 years in the Raritan River from three sediment cores collected over a salinityand pollution gradient that extends from Cheesequake to New Brunswick. We analyzed for (1) heavymetals and organic pollutants associated with local and regional activities; (2) pollen to identify thedeforestation horizon and other vegetation changes; and (3) diatoms to determine changing nutrientlevels. We placed pollutants and indicators of environmental health in a chronological framework usingradiocarbon dating of plant rhizomes, timing of deforestation and other major vegetation alterations,known deposition of heavy metals and short-lived radionuclides (210Pb and 137Cs). Extending thepollution history to include pre-European baseline conditions allows us to assess the impacts ofanthropogenic activity to help inform restoration targets and improve monitoring guidelines.

2. STUDY AREA

5. RESULTS AND DISCUSSION

Figure 3: Lead-210 activity in cores from Raritan River Crossing and Brookside Ave Sites. Lead-210 was used to estimate that over past 100-130 years, approximately 50 cm of sediment were deposited at Site 1 and 40 cm of sediment at Site 4.

Figure 2: Diatoms were grouped by their nutrient preferences:A. Brookside: Freshwater diatoms grouped by high (1) and low (2) nutrient

preferences (Potapova & Charles, 2007), andB. Brookside and Cheesequake: Marine and Brackish diatoms grouped into high

(1) and low (2) nutrient preferences (Potapova, et al. 2015).

Metals and organic pollutants were also extracted and compared in the core

Figure 4: Pollen was used to look for changes in vegetation related to known deforestation events. When deforestation occurs, Quercus is replaced with Ambrosia (Hilgartner and Brush, 2006). Images from: The University of Tulsa Aerobiology Laboratory, Tulsa Pollen Home Page.

Quercus sp. Ambrosia sp.

Figure 1: Map of study sites along the Raritan River in Middlesex County, New Jersey.

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Table 1: Summary of mean concentrations from sediment analyses.

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1. Epithemia turgida, a low-nutrient freshwater diatom

1. Caloneis bacillum, a low nutrient marine/brackish diatom(image from Diatoms of North America)

2. Cyclotella meneghiniana, a high-nutrient freshwater diatom

2. Cocconeis placentula, a high-nutrient marine/brackish diatom

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Figure 4: Sediment concentrations of main metal pollutants, organic pollutants, and diatoms from cores. Pink area represents post-industrial sediments, yellow is pre-industrial/post-deforestation, green is pre-deforestation

Brookside Cd (mg/kg) Cu (mg/kg) Ni (mg/kg) Pb (mg/kg)PCB

(ug/kg)OPC (ug/kg)

Low Nutrient Diatoms (%)

High Nutrient Diatoms (%)

Post-Industrial 0.53 171.03 33.05 143.27 100.82 26.34 11.17 6.67Post-deforestation Pre-Industrial 0.15 111.23 21.09 14.31 NA NA 12.00 18.00

Pre-deforestation 0.12 110.12 31.19 33.64 NA NA 28.75 3.75Bridge Site

Post-Industrial 0.79 80.15 32.72 111.14 82.62 15.59 9.80 28.00Post-deforestation Pre-Industrial 0.14 128.43 20.83 20.06 NA NA 20.00 13.33

CheesequakePost-Industrial 0.23 126.13 20.96 121.75 47.76 17.53 3.30 9.96

Post-deforestation Pre-Industrial 0.26 12.47 20.56 17.46 29.39 8.53 6.45 13.45Pre-deforestation 0.06 6.58 8.25 5.91 42.31 8.01 17.95 3.57