laboratory-estimation-net-trophic-transfer-efficiencies-pcb-congeners

Laboratory Estimation of Net Trophic Transfer Efficiencies of PCB Congeners to Lake Trout (<em>Salvelinus namaycush</em>) from Its Prey

A technique for laboratory estimation of net trophic transfer efficiency (&#947;) of polychlorinated biphenyl (PCB) congeners to piscivorous fish from ...

Grand Valley State University

Lake whitefish (Coregonus clupeaformis) were fed rainbow smelt (Osmerus mordax) in four laboratory tanks over a 133-d experiment. At the start of the experiment, 10 to 14 of the fish in each tank were sacrificed, and the concentrations of 40 polychlorinated biphenyl (PCB) congeners within these fish were determined. Polychlorinated biphenyl congener concentrations were also determined in the 15 lake whitefish remaining in each of the four tanks at the end of the experiment as well as in the rainbow smelt fed to the lake whitefish. Each lake whitefish was weighed at the start and the end of the experiment, and the amount of food eaten by the lake whitefish during the experiment was tracked. Using these measurements, net trophic transfer efficiency (gamma) from the rainbow smelt to the lake whitefish in each of the four tanks was calculated for each of the 40 PCB congeners. Results showed that gamma decreased exponentially as log K(OW) for the congeners increased from 6 to 8. Further, gamma averaged 0.70 for the tetrachloro congeners but averaged only 0.45 for the higher chlorinated congeners.

Net trophic transfer efficiencies of polychlorinated biphenyl congeners to lake whitefish (Coregonus clupeaformis) from their food.

Municipal solid waste landfill leachate must be removed and treated to maintain landfill cover integrity and to prevent contamination of surface and ground waters. From 2003 to 2007, we studied an onsite disposal system in Ottawa County, Michigan, where leachate was spray irrigated on the vegetated landfill cover. We established six 20-m-diameter circular experimental plots on the landfill; three were spray irrigated as part of the operational system, and three remained as untreated control plots. We quantified the effects of leachate application on soil properties, soil solution chemistry, vegetative growth, and estimated solute leaching. The leachate had high mean levels of electrical conductivity (0.6-0.7 S m(-1)), Cl (760-900 mg L(-1)), and NH(4)-N (290-390 mg L(-1)) but was low in metals and volatile organic compounds. High rates of leachate application in 2003 (32 cm) increased soil electrical conductivity and NO(3)-N leaching, so a sequential rotation of spray areas was implemented to limit total leachate application to <9.6 cm yr(-1) per spray area. Concentrations of NO(3)-N and leaching losses remained higher on irrigated plots in subsequent years but were substantially reduced by spray area rotation. Leachate irrigation increased plant biomass but did not significantly affect soil metal concentrations, and plant metal concentrations remained within normal ranges. Rotating spray areas and timing irrigation to conform to seasonal capacities for evapotranspiration reduced the localized impacts of leachate application observed in 2003. Careful monitoring of undiluted leachate applications is required to avoid adverse impacts to vegetation or soils and elevated solute leaching losses.

Landfill cover soil, soil solution, and vegetation responses to municipal landfill leachate applications.

Urbanization of watersheds can impose multiple stressors on stream, wetland, and lake ecosystems. Sediment contamination, alterations to the natural hydrologic regime, and nutrient loading are examples of these stressors which often occur simultaneously. As a consequence, restoration is challenged by the multi-stressor reality of most urban watersheds. The goal of this study was to compare two watersheds in western Michigan, both with substantial urban development, but with different levels of sediment contamination resulting from historic industrial activities, to determine the effects of contamination on invertebrate and fish community structure. The study included multiple sites on both streams, two wetlands adjacent to each stream, and the embayments where each stream emptied into Mona Lake. We compared a suite of abiotic parameters including sediment contamination, sediment toxicity, and water column chemical/physical conditions as well as fish and invertebrate community structure. Sediment contaminants, including heavy metals and polycyclic aromatic hydrocarbons, were found in higher concentrations and survival of test organisms in toxicity bioassays was reduced in the more industrialized watershed. Fewer insect taxa, especially the sensitive Ephemeroptera, Plecoptera, and Trichoptera, were found in the more industrialized system. Fish taxa richness and catch per unit effort were reduced in the wetlands of the more industrialized watershed as well and both invertebrate and fish index of biotic integrity scores were also lower in the more industrialized system. Our study demonstrates that contamination due to historic industrial activities can have substantial and lasting effects on biotic communities of multiple habitat types well downstream of where the activities occurred.

Sediment contamination and faunal communities in two subwatersheds of Mona Lake, Michigan.

Physicochemical characterization, automated ribosomal intergenic spacer analysis (ARISA) community profiling, and 16S rRNA gene sequencing approaches were used to study bacterial communities inhabiting submerged Lake Huron sinkholes inundated with hypoxic, sulfate-rich groundwater. Photosynthetic cyanobacterial mats on the sediment surface were dominated by Phormidium autumnale, while deeper, organically rich sediments contained diverse and active bacterial communities.

Benthic bacterial diversity in submerged sinkhole ecosystems.

Pacific salmon (Oncorhynchus spp.) can transport bioaccumulated organic pollutants to stream ecosystems where they spawn and die. We quantified PCBs, DDE, and PBDEs in resident fishes from 13 Great Lakes tributaries to assess biotransport of pollutants associated with introduced Pacific salmon. Resident fishes sampled from salmon spawning reaches had higher mean pollutant concentrations than those from upstream reaches lacking salmon (93.5 and 4.1 μg x kg(-1) [PCB], 24.0 and 3.1 μg x kg(-1) [DDE], 8.5 and 1.0 μg x kg(-1) [PBDE], respectively), but differences varied substantially among lake basins. In Lake Michigan tributaries, PCB concentrations in resident fishes from salmon reaches were over four times higher than those from salmon reaches in Lake Huron and over 30 times higher than those from Lake Superior. Moreover, resident fish pollutant concentrations were better explained by pollutant inputs from salmon (μg x m(-2); R(2) = 0.76 [PCB], 0.64 [DDE], 0.64 [PBDE]) than by land development/agriculture, watershed area, resident fish species, body length, or lipid content. These results suggest that pollutant dispersal to stream ecosystems via biotransport is an often overlooked consequence of salmon stocking and historical food web contamination in the Great Lakes. Our findings have implications for Great Lakes management, including dam removal and wildlife conservation.

Resident fishes display elevated organic pollutants in salmon spawning streams of the great lakes.

Lake trout (Salvelinus namaycush) were fed bloater (Coregonus hoyi) in eight laboratory tanks over a 135-d experiment. At the start of the experiment, four to nine fish in each tank were sacrificed, and the concentrations of 75 polychlorinated biphenyl (PCB) congeners within these fish were determined. Polychlorinated biphenyl congener concentrations were also determined in the 10 lake trout remaining in each of the eight tanks at the end of the experiment as well as in the bloater fed to the lake trout. Each lake trout was weighed at the start and the end of the experiment, and the amount of food eaten by the lake trout was recorded. Using these measurements, net trophic transfer efficiency (γ) from the bloater to the lake trout in each of the eight tanks was calculated for each of the 75 congeners. Results showed that γ did not vary significantly with the degree of chlorination of the PCB congeners, and γ averaged 0.66 across all congeners. However, γ did show a slight, but significant, decrease as log K(OW) increased from 6.0 to 8.2. Activity level of the lake trout did not have a significant effect on γ.

Net trophic transfer efficiencies of polychlorinated biphenyl congeners to lake trout (Salvelinus namaycush) from its prey.

A remote sensing technique was developed which combines a Geographic Information System (GIS); Google Earth, and Microsoft Excel to identify home locations for a random sample of households in rural Haiti. The method was used to select homes for ethnographic and water quality research in a region of rural Haiti located within 9 km of a local hospital and source of health education in Deschapelles, Haiti. The technique does not require access to governmental records or ground based surveys to collect household location data and can be performed in a rapid, cost-effective manner.

Using ArcMap, Google Earth, and Global Positioning Systems to select and locate random households in rural Haiti.

A field study assessing the sustainability and efficacy of 55 biosand filters installed during 1999-2010 was conducted in the Artibonite Valley, Haiti during 2011. Twenty-nine filters were still in use. Duration of filter use ranged from < 1 to 12 years. Water quality, microbial analysis, and flow rate were evaluated for each functioning filter. Kaplan-Meier analysis of filter lifespans showed that filter use remained high (> 85%) up to seven years after installation. Several filters were still in use after 12 years, which is longer than documented in any previous study. Filtered water from 25 filters (86%) contained Escherichia coli concentrations of < 10 most probable number of coliforms/100 mL. Recontamination of stored filtered water was negligible. Bacterial removal efficiency was 1.1 log(10). Comparable results from previous studies in the same region and elsewhere show that biosand filter technology continues to be an effective and sustainable water treatment method in developing countries worldwide.

Long-term field performance of biosand filters in the Artibonite Valley, Haiti.

Concentrations of 86 congeners of polychlorinated biphenyls (PCBs) were determined for 25 adult female and 25 adult male burbot (Lota lota) from Lake Erie. Significant differences in mean proportions of total PCB concentration between males and females ages 14-17 were found for 26 congeners. Males generally had higher mean proportions of hexachloro congeners, whereas females had higher mean proportions of more highly chlorinated congeners. In contrast, only four congeners exhibited differences between males and females ages 6-13 in mean proportions of total PCB. Therefore, the sexual difference in PCB congener distribution widened for older burbot. Males ages 14-17 also had higher proportions of certain hexachloro congeners than the other three demographic groups (males ages 6-13, females ages 6-13, and females ages 14-17) we examined. The reverse was true for more highly chlorinated congeners. The results supported a previous hypothesis that older male burbot spent a substantial amount of time feeding in the vicinity of mouths of rivers with sediment contaminated with PCBs. However, additional studies are needed to clarify and corroborate this apparent "hot spot" effect, such as seasonal movements, spatial distributions, and diet of burbot; and PCB congener distributions of various species of prey fishes captured at various locations throughout the eastern basin of Lake Erie and at different locations in the contaminated rivers.

Sexual difference in PCB congener distributions of burbot (Lota lota) from Lake Erie.

We compared the distributions of the congeners of polychlorinated biphenyls (PCBs) detected in whole-body samples of burbot (Lota lota) from Great Slave Lake and Lake Erie. Total PCB concentrations in Great Slave Lake burbot were about 1/60 of the concentrations in Lake Erie burbot. Burbot from Great Slave Lake contained a higher proportion of lower-chlorinated (2-6 chlorines) congeners than did burbot from Lake Erie; the reverse occurred for more highly chlorinated (7-9 chlorines) congeners. Hexachloro congeners, followed by pentachloro congeners, dominated the proportions of total PCB in burbot from both lakes. There were no differences between sexes in whole-body samples or between gonad and somatic tissues in the proportions of the 39 congeners and three sets of co-eluters detected in burbot from Great Slave Lake. In contrast, there were distinct sex differences in congener distributions for older burbot from Lake Erie. Our results generally supported a prediction of higher proportions of lower-chlorinated PCB homologs in organisms in remote polar areas. However, the latitudinal effect on PCB congener distribution may be more complex than that portrayed in previous studies. Environ Toxicol Chem © 2014 SETAC.

Richard R. Rediske

Annis Water Resources Institute

Grand Valley State University

Laboratory Estimation of Net Trophic Transfer Efficiencies of PCB Congeners to Lake Trout (Salvelinus namaycush) from Its Prey

Richard R. Rediske

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Grand Valley State University

Laboratory Estimation of Net Trophic Transfer Efficiencies of PCB Congeners to Lake Trout (Salvelinus namaycush) from Its Prey

Annis Water Resources Institute