Grantee Research Project Results
1999 Progress Report: Trophic Transfer of Atmospheric and Sedimentary Contaminants Into the Great Lakes Fisheries Controls on the Ecosystem Scale Response Times
EPA Grant Number: R825151Title: Trophic Transfer of Atmospheric and Sedimentary Contaminants Into the Great Lakes Fisheries Controls on the Ecosystem Scale Response Times
Investigators: Baker, Joel E. , Ostrom, Nathaniel E. , Eadie, Brian , Hall, Don , Ostrom, Peggy , Coon, Tom
Institution: University of Maryland - College Park , Michigan State University , NOAA / GLERL
EPA Project Officer: Packard, Benjamin H
Project Period: October 1, 1996 through September 30, 1999
Project Period Covered by this Report: October 1, 1998 through September 30, 1999
Project Amount: $617,254
RFA: Ecological Assessment (1996) RFA Text | Recipients Lists
Research Category: Ecological Indicators/Assessment/Restoration , Aquatic Ecosystems
Objective:
During the past two decades, inventories of persistent, bioaccumulative organic contaminants have decreased dramatically in the Great Lakes ecosystem, clearly demonstrating the effectiveness of regulatory decisions about the production and use of certain classes of industrial and agricultural chemicals. For example, concentrations of polychlorinated biphenyls (PCBs) decreased in Great Lakes surface waters, surficial sediments, and fish during the 1970s and early 1980s in response to a restriction on PCB production in 1971. Initial rates of decline of PCBs in the Great Lakes were rapid during the 1970s and early 1980s, with pseudo first order rate constants of 0.2 year-1 for Lake Superior surface waters and ranging from 0.058 to 0.47 year-1 for fish. Clearly, the Great Lakes ecosystem responded favorably and, in retrospect, predictably to decreased loadings of PCBs. Unfortunately, the rate of decline in PCB levels in the Great Lakes ecosystem apparently has slowed during the second half of the 1980s, and the most recent data show little or no change in PCB levels in the Great Lakes fishery. This apparent stabilization of PCB levels near the Food and Drug Administration (FDA) advisory level (2 µg/g-wet tissue) is problematic for Great Lakes water quality managers. On one hand, the persistence of PCBs in Great Lakes fish has led to the call for additional regulations, as embodied in the Great Lakes Water Quality Guidance. Others have argued that the decrease in the rate of recovery of PCBs in the Great Lakes is a natural consequence of internal recycling and continental-scale atmospheric exchange, and that further regulations are neither cost effective or warranted.
The purpose of this study is to quantify the absolute and relative magnitudes of PCB transfers into the Great Lakes fisheries from three exposure routes: (1) atmospheric deposition transferred through the pelagic food web; (2) atmospheric deposition transferred, via rapidly settling particles, through the benthic food web; and (3) transfer from historically contaminated, in-place sediments through the benthic food web. This is being accomplished by using stable isotopes and PCBs as tracers of carbon and bioaccumulative contaminants, respectively, through the water column and food web of Grand Traverse Bay, an embayment of Lake Michigan. We hypothesize that each of these three routes differ both in their efficiencies of contaminant transfer and in their characteristic response times. This study will result in a quantitative, process-driven model of contaminant transfers in the Great Lakes food webs that distinguishes between new (i.e., regional atmospheric deposition) and in-place (i.e., recycling from contaminated sediments) sources of contaminants that support the slowly changing contaminant inventories in the highest trophic levels of the Great Lakes.
Progress Summary:
Intensive field work began in Grand Traverse Bay, Lake Michigan, in spring 1997, and is scheduled to be completed in August 1999. During both 1997 and 1998, cruises were conducted approximately monthly during the ice-free periods to collect surface water (dissolved and particulate chemical contaminants, seston), representative members of the food web (plankton, mysid, amphipods, sculpin, alewife, bloater, lake trout), air (gaseous and aerosol-bound chemical contaminants), settling particles (via sequencing sediment traps), and intact sediment cores. Sampling objectives were met in both years, with sufficient samples collected to quantify the seasonal dynamics of PCB transport and accumulation in the food web. Sequencing sediment traps have been deployed at two depths (just below the thermocline and 5 m above the bottom) at two locations in Grand Traverse Bay. These traps are programmed to collect sequential 2-week integrated settling particle samples.
To date, all water, air, and biota samples have been analyzed for PCB congeners. Stable isotope analysis of seston and food web members is nearly complete, as is the stomach analysis of the collected fish. Two sediment cores collected in 1998 have been radiodated using 210Pb and have been analyzed for PCB and polycyclic aromatic hydrocarbon (PAH) accumulation rates. Sediment traps have been retrieved through September 1998, with additional deployments continuing until late August 1999. All sediment traps samples have been split and analyzed for dry mass. Analysis of sediment trap material for PCBs, carbon, and isotopes is ongoing.
Although considerable data analysis is yet to be completed, results to date indicate the following:
Future Activities:
Work continues to complete laboratory analysis of the samples collected in this study. Although all biota analysis is nearly complete, considerable work remains to analyze the sediment trap samples (we extended the length of the sequencing sediment trap deployment through August 1999 so that the sampling record could extend over three summers). Data synthesis and integration continues, including preparing the manuscripts listed above. A no-cost extension has been requested to allow completion of these analyses.Journal Articles on this Report : 5 Displayed | Download in RIS Format
Other project views: | All 34 publications | 5 publications in selected types | All 5 journal articles |
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Feuerstein TP, Ostrom PH, Ostrom NE. Isotopic biogeochemistry of dissolved organic nitrogen: a new technique and application. Organic Geochemistry 1997;27(7-8):363-370. |
R825151 (1999) |
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McCusker EM, Ostrom PH, Ostrom NE, Jeremaison JD, Baker JE. Seasonal variation in the biogeochemical cycling of seston in Grand Traverse Bay, Lake Michigan. Organic Geochemistry 1999;30(12):1543-1557. |
R825151 (1999) |
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Schneider AR, Stapleton HM, Cornwell J, Baker JE. Recent declines in PAH, PCB, and toxaphene levels in the northern Great Lakes as determined from high resolution sediment cores. Environmental Science & Technology 2001;35(19):3809-3815. |
R825151 (1999) |
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Stapleton HM, Masterson C, Skubinna J, Ostrom P, Ostrom NE, Baker JE. Accumulation of atmospheric and sedimentary PCBs and toxaphene in a Lake Michigan food web. Environmental Science & Technology 2001;35(16):3287-3293. |
R825151 (1999) |
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Stapleton HM, Skubinna J, Baker JE. Seasonal dynamics of PCB and toxaphene bioaccumulation within a Lake Michigan food web. Journal of Great Lakes Research 2001;28(1):52-64. |
R825151 (1999) |
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Supplemental Keywords:
PCBs, PAHs, sediment traps, sediment cores, Great Lakes, Grand Traverse Bay, Lake Michigan, MI, Michigan., RFA, Scientific Discipline, Water, Waste, Geographic Area, Ecosystem Protection/Environmental Exposure & Risk, Nutrients, Environmental Chemistry, Contaminated Sediments, Ecosystem/Assessment/Indicators, Ecosystem Protection, exploratory research environmental biology, Chemical Mixtures - Environmental Exposure & Risk, Ecological Effects - Environmental Exposure & Risk, Environmental Monitoring, Air Deposition, Ecological Effects - Human Health, Ecology and Ecosystems, Atmospheric Sciences, Ecological Risk Assessment, Ecological Indicators, Great Lakes, aquatic ecosystem, fate and transport, hydrological stability, ecological exposure, fate, carbon cycling, ecosystem assessment, sediment contaminant effects, trophic transfer, response times, contaminated sediment, organic contaminant transfers, benthic food web, chemical contaminants, atmospheric nitrogen deposits, biological integrity, nutrient stress, ecological assessment, polychlorinated biphenyls, regional scale, ecosystem stress, fish , atmospheric contaminants, Lake Michigan, benthic nutrients, bioaccumulation, atmospheric depositionProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.