45 research outputs found
Zooplankton Abundance and Diversity in Spring Lake, Florida, 1973-1976
Seasonal variation in zooplanton abundance and diversity in Spring Lake, Florida was studies between 1973 - 1976. This clear, sand bottom lake is considered among the most oligotrophic in central Florida. Sixty rotifer species, sixteen cladoceran species, and seven copepod species were collected during the three year study. Annual mean zooplanton abundances ranged between 70 individuals/l and 80 individuals/l. Rotifers were more abundant than either cladocerans or adult copepods. Rotifers and immature crustaceans comprised nearly 75% of the annual mean zooplankton abundance. There was no significant difference (P \u3c 0.05) between years for the annual mean abundance of zooplankton. The monthly mean abundance of cladocerans and adult copepods was generally less than 5 individuals/l. The greater abundance of rotifers in comparison to other zooplankton was mainly responsible for the variation in the values of the Shannon and Simpson Indices. The monthly mean Shannon Index was usually between 3.0 and 4.0. Seasonal differences in zooplankton abundance were apparently due to water temperature and specific conductivity for the 1974 - 1975 and 1975 - 1976 study years. Shannon diversity was significantly correlated with dissolved oxygen for the 1973 - 1974 and 1974 - 1975 study years
Evaluation of alternative approaches for screening contaminated sediments and soils for polychlorinated dibenzo-\u3ci\u3ep\u3c/i\u3e-dioxins and polychlorinated dibenzofurans
Traditional high resolution mass spectrometry (HRMS) analysis for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) can be time consuming and expensive. Consequently, alternative methods are of great interest to regulatory agencies and others characterizing contaminated sites. One factor that hinders acceptance of alternative methods is a lack of performance information that assesses the alternative method’s impacts on analytical results. The U.S. Environmental Protection Agency’s Superfund Innovative Technology Evaluation Monitoring and Measurement Technologies Program (EPA SITE MMT) encourages the development and implementation of innovative and alternative monitoring methods by providing performance information on site characterization technologies. This paper presents a comparison of the results obtained from laboratory-based alternative approaches for screening sediment and soil samples for dioxin toxicity equivalents (TEQD/F) to results obtained using traditional HRMS. The laboratory-based approaches included modifying the traditional HRMS analysis to make it more cost-effective (alternate 1613B), analyzing extracts that had been prepared for HRMS using low resolution mass spectrometry, and determining total organic carbon (TOC) content as an indicator of PCDD/F content. These comparisons demonstrated that TEQD/F values generated using toxicity equivalency factors proposed by the World Health Organization in 1998 applied to alternate 1613B and LRMS analyses have a strong linear correlation to the TEQD/F values derived in the same fashion from traditional HRMS analysis. These results would have placed \u3e90% of the samples within the same concentration intervals using ranges of \u3c0.05, 0.05–0.50, 0.50–5, and \u3e5 ng TEQ/g. Natural log transformed data for TOC had significantly weaker correlation to TEQD/F, indicating that TOC is not a reliable indicator of TEQD/F concentrations
Recommended from our members
Field technology evaluations in EPA`s Environmental Technology Verification (ETC) Program
The performance evaluation of innovative environmental technologies is an integral part of the US Environmental Protection Agency`s (EPA) mission. The Environmental Technology Verification (ETV) Program was created by the Agency to facilitate the deployment of innovative technologies through performance verification and information dissemination. The goal of the ETV Program is to further environmental protection by substantially accelerating the acceptance and use of improved and cost-effective technologies by providing independent and credible assessments of environmental technologies. This report will overview ORNL`s verification activities, including evaluation of polychlorinated biphenyl field analytical techniques, decision support software, and field extraction technologies
Recommended from our members
Field Technologies for the Measurement of PCBs
The collaborative effort between the US Environmental Protection Agency (EPA), US Department of Energy (DOE), and the Oak Ridge National Laboratory (ORNL) represents a viable team to administer, plan, execute, and report on demonstrations of commercially available field characterization and monitoring technologies. This effort is part of the EPA`s Environmental Technology Verification (ETV) Program. One of the overriding goals of this effort is to develop regulatory-accepted and cost effective alternatives to conventional fixed laboratory analyses through the identification and evaluation of innovative, field technologies. A technology demonstration of polychlorinated biphenyl (PCB) field analytical techniques will occur during July 22 through 30, 1997. The demonstration will be conducted at a DOE site (ORNL) where there is a substantial repository of PCB-contaminated materials from multiple DOE sites. Technology developers with PCB monitoring instrumentation will be evaluated. These instruments will include field portable gas chromatographs with surface acoustic wave and electron capture detectors, and field analysis kits, such as immunoassay and ion specific electrode kits. These instruments are suitable for the quantification of PCBs in a variety of matrices. Soil and surface samples will be evaluated during the demonstration. The demonstration will focus on the current DOE-Oak Ridge analytical needs to support Toxic Substance and Control Act (TSCA) decisions, while allowing developers to showcase the features of their technologies