Showing papers in "Virginia journal of science in 2005"

Phytoplankton Development Within Tidal Freshwater Regions of Two Virginia Rivers, USA

Abstract: Phytoplankton composition and the range of seasonal patterns of abundance are presented for the tidal freshwater regions in two Virginia rivers based on data accumulated monthly from 1986 through 1999. Diatoms dominated the flora during sprir).g, summer, and fall, whereas, other taxonomic categories were more representative when the river flow rates decreased, allowing for a more stable water system and increased residency time within this tidal region during summer and early fall. This summer/fall period was associated with increased water temperatures, higher productivity rates and chlorophyll levels, increased total phytoplankton abundance and species diversity. The major components of the summer flora were autotrophic picoplankton, chlorophytes, and cyanobacteria. Mean, maximum, and minimum monthly abundance figures are given for the different phytoplankton categories, and total phytoplankton biomass and abundance, over this 13-year period. Although one station showed considerable influx of oligohaline water into its tidal freshwater region during sampling, no significant relationships were associated with phytoplankton biomass or productivity to these changing salinities.

Bats of Skydusky Hollow, Bland County, Virginia

Abstract: During the period 22 November 1999 -11 October 2001, winter hibernacula surveys, spring staging/autumn swarming surveys, and summer surveys for bats were completed in caves of Skydusky Hollow, Bland County, Virginia. During winter, 12 caves were entered and 16,185 bats counted: 235 Myotis soda/is (Indiana bat), 14,475 Myotis lucifugus (little brownmyotis), 12 Myotis septentrionalis (northern myotis), 7 Myotis leibii (eastern small-footed myotis), 1,441 Pipistrellus subflavus (eastern pipistrelle), and 15 Eptesicus fuscus (big brown bat). Myotis soda/is hibernated in thermally stable areas of 7 9°C. The largest concentration of M lucifugus (n = 4,280) hibernated in an area that was cooler (6.5°C) than areas used by M soda/is. The remaining 6,300 M lucifugus hibernated at temperatures similar to, or slightly cooler than, temperatures used by M soda/is. Intra-cave (and possibly inter-cave) movements of M lucifugus and M soda/is during the season of hibernation concentrated bats in cooler areas of the caves. An unusually large concentration of P. subjlavus (n = 920) hibernated in Coon Cave in a warm (8.6 9.7°C), stable environment. Proportions of species of bats captured during spring staging and autumn swarming varied from proportions found during winter hibernation. Mating and perhaps other social functions affect patterns of autumn use. No concentration of bats used the caves during

The Small Mammals of Isle of Wight County, Virginia, as Revealed by Pitfall Trapping

Abstract: In a study conducted in mid-winter, pitfall traps were used to assess the small mammal communities on 14 grids set in open habitats in Isle of Wight County in eastern Virginia. In all, 136 shrews of three species and 103 rodents of five species were trapped. Least shrews (n= 110) comprised 46 percent of small mammals and 80 percent of shrews. Eastern harvest mice (n=62) were the most common rodents. Reproduction was detected only in pine voles and southern bog lemmings. The majority of small mammals of the region were trapped during this month-long study. INTRODUCTION As part of a study to determine the western extent of populations of the then federally threatened Dismal Swamp southeastern shrew, Sorex longirostris fisheri, I conducted a survey of small mammals in Isle of Wight County, located just west of the City of Suffolk and lying approximately 40 km west of the Great Dismal Swamp National Wildlife Refuge in eastern Virginia. Using a standard protocol to study the Dismal Swamp southeastern shrew, an assistant and I established 14 study grids at different locations throughout the county. Trapping between 6 January and 6 February 1992, we collected 239 small mammals of eight species. This report relates the details of the types of small mammals, and their associations, in a coastal plain county in eastern Virginia. MATERIALS AND METHODS The southeastern shrew, the species of particular interest, is known to achieve greatest numbers in early successional habitats, such as oldfields, recently clearcut forests, and sites that are infrequently mowed (Rose et al. 1990). Powerline rights of way provide excellent habitat for such small mammals because they are mowed at 3-5 year intervals to prevent excessive growth of shrubs and trees, thereby continually setting back biological succession and promoting the persistence of perennial grasses and other herbaceous plants. Furthermore, because powerlines cross roadways, these habitats are easily reached, an additional benefit. Several high-voltage powerlines form a network across Isle of Wight County (Figure 1 ), many radiating from the Surry Nuclear power plant located on the south side of the James River. Thus, wherever county roads crossed the 30 m wide powerlines, I examined the vegetative stage of the habitat and usually was able to establish one or two study grids nearby. The trapping grids were placed on sites with vegetation that is typical of early succession in the region. Grasses, mostly in the genera Andropogon, Panicum, and Uniola, dominated the vegetation of most grids, but sedges (Carex spp.) and even softrushes (Juncus spp.) were present on wetter places. Many grids had American cane (Arundinaria gigantea) and other woody elements, such as brambles (Rubus spp.), Jananese honevsuckle {f,onicera ianonicat and tree seedlings_ esneci::illvofsweet P-11m Virginia Journal of Science, Vol. 56, No. 2, 2005 http://digitalcommons.odu.edu/vjs/vol56/iss2 1111 84 VIRGINIA JOURNAL OF SCIENCE

Assessment of Human Health Risks from Chemically Contaminated Lake Fishes In Greece

Abstract: Objectives were to conduct screening level surveys oflocally consumed fish tissues in vicinities of two lakes (Kastoria and Pamvotis) in Greece to determine the presence of halogenated organic compounds and determine carcinogenic and non-carcinogenic human health risks associated with the consumption of sampled fish tissues. Results estimate the Incremental Lifetime Cancer Risks (ILCR) and Hazard Index (HI) values for the two local populations using site-specific population data. These results were compared to analyses conducted using U.S. Environmental Protection Agency default values in an effort to determine the applicability of USEP A default values to assessments of risks in non U.S. populations. Using site specific data, 87 % of the mean ILCRs calculated for total populations and sub-populations (i.e. female adult, female youth, male adult and male youth) consuming fishes from the two lakes we studied were above USEPA' s acceptable cancer risk of l .OE-06; 53 % of the mean Hls were greater than 1.0. The USEPA default value (0.054 kg/d) for ingestion rate (IR) is considerably lower than the mean site specific IRs derived from populations in vicinity of Lake Kastoria (0.20; min.=0.09; max.=0.29 kg/d) and Lake Pamvotis (0.10; min.=0.01 ; max.=0.21 kg/d). These differences point to the need for the development of default values specific to the regions and population consumption patterns within

Fish Consumption Patterns of Populations in Vicinities of Lake Kastoria and Lake Pamvotis, Greece

Abstract: Virginia Journal of Science Volume 56 Number 3 Fall 2005 Fish Consumption Patterns of Populations in Vicinities of Lake Kastoria and Lake Pamvotis, Greece Eugene G. Maurakis, 1,2,3 David V. Grimes,4 and Dimitra Bobori 5 lScience Museum ofVirginia, 2500 W. Broad St., Richmond, VA 24542 2School of Continuing Studies, University of Richmond, VA 23173 3School of Environmental Science and Policy, George Mason University, Fairfax, VA 22030, 4Virginia Department of Environmental Quality 4949 A Cox road, Glen Allen, VA 23060 5Department of Biology, Aristotle University, Thessaloniki, Greece 54006. ABSTRACT Objectives are to establish fish consumption patterns of populations in vicinities of two lakes (Kastoria and Pamvotis) in Greece for use in the assessment of risks associated with consumption of fishes in these agrichemically impaired lakes. Parameters measured were demographics (i.e., gender, age, weight, education level, occupation, residency), freshwater fish eating frequency, species and sizes of fishes consumed, and fish consumption habits [i.e., quantity, parts, and preparation method). All annual mean sitespecific consumption rates of the four gender-age class sub-populations surveyed in vicinity of Lake Kastoria (avg.range= 0.103-0.29 kg/day) exceed those of Greece (0.066 kg/day), EU (0.068 kg/day), Spain (0.104 kg/day), Portugal (0.159 kg/day), and the USEPA default value (0.054 kg/day) with two exceptions. Female consumption rates (0.087-0.103 kg/day) of Perea fluviatilis were below annual consumption rates of Spain and Portugal. Similarly, annual mean site-specific consumption rates of Anguilla anguilla and Cyprinus carpio by male (0.199-0.210 kg/day) and female adults (0.0960.157 kg/day) in vicinity of Lake Pamvotis exceeded those of Greece, EU, Spain, Portugal, and the USEP A default value. Survey results indicate bettereducated Greeks to be higher consumers offish; however, market availability appears to be a stronger determinant of food choice in comparison to health education. All populations in vicinities of both lakes preferred to eat fried fishes with one exception: grilled C. carpio from Lake Pamvotis was preferred by female and male adults.