121 research outputs found
Mercury Exposure within Songbird Communities in the Adirondack Park of New York State
Mercury (Hg) is a globally widespread and toxic pollutant that bioaccumulates and biomagnifies within terrestrial and aquatic food webs. Numerous adverse effects been documented in wildlife species, such as avian communities, exposed to elevated environmental Hg levels, specifically those inhabiting Hg-sensitive habitats, such as wetland and montane ecosystems. The primary goals of this dissertation were to examine spatial and seasonal patterns of Hg exposure for targeted songbird species occupying Sphagnum bog, upland forest and high elevation habitat types in the Adirondack Park of New York State, a biological Hg hotspot. From 2009–2010, Catharus thrushes were sampled at 13 study plots along an elevational gradient (450-1400 meters) on Whiteface Mountain. Mercury concentrations were observed to increase along the elevational gradient to 1,075 meters, followed by declining blood concentrations with further increases in elevation. These results are consistent with studies conducted at the same study sites which documented increases in atmospheric Hg deposition and soil Hg along the gradient, with the highest concentrations also occurring within mid- and high elevation forests. A seasonal pattern of increasing, followed by decreasing, blood Hg concentrations was detected across thrush species over the course of the breeding season. During 2008, 2009 and 2011, songbird species were sampled from study sites at Sphagnum bog and adjacent upland forests. Songbirds inhabiting Sphagnum bogs displayed significantly higher blood Hg concentrations than species within the surrounding forests, and similar patterns of species-level bioaccumulation were evident across each study site. There were no overall seasonal changes in Hg concentrations documented for Sphagnum bog songbirds, which remained consistently elevated throughout the breeding season. However, an overall seasonal pattern of increasing, followed by decreasing blood Hg was observed across upland forest songbird species. A comparative analysis was also conducted utilizing subsets of data from wetland-adjacent upland forests and those sampled on Whiteface Mountain. These results indicated that forest songbirds in proximity to wetland sites had significantly higher Hg concentrations than forest songbirds sampled at Whiteface Mountain, a location well-removed from wetlands. This finding suggests the potential influence of wetland ecosystems on biota within the surrounding landscape. Taken together, these results provide evidence that high-Hg habitat types, such as Sphagnum bog ecosystems and montane forests, influence songbird Hg exposure and the associated spatial patterns that were observed as part of this dissertation research. Seasonal fluctuations in blood Hg concentrations were highly variable across study sites and are likely reflective of multiple contributing variables, including dietary selection and molting cycles. Finally, these results contribute to regional wildlife Hg databases and demonstrate the importance of monitoring efforts to further characterize Hg exposure patterns within bioindicator species inhabiting sensitive ecosystems in New York State
Jobs from Renewable Energy and Energy Efficiency
According to research by Roger Bezdek for the American Solar Energy Society (ASES), the renewable energy (RE) and energy efficiency (EE) industries created a total of 8.5 million jobs (direct and indirect) in 2006; 450,000 jobs in RE and 8 million jobs in EE throughout the United States. As many as 1 out of 4 workers in the United States will be working in RE or EE industries by 2030. The 40 million jobs are not just engineering?related, but also include millions of new jobs in manufacturing, construction, accounting, and management.
Biodiversity Research Institute
Population declines of migratory songbird species throughout their range are well documented and have been associated with a complex variety of stressors, including, but not limited to: environmental pollution; habitat loss, conversion, and fragmentation; energy development and generation; and climate change. To better understand these and other potential impacts on songbird populations, biologists from Biodiversity Research Institute (BRI) collect scientific data to address these stressors through studies that target mercury exposure and effects assessments, determine movement and distribution patterns, and integrate findings with conservation and management strategies. Through an emphasis on neotropical migrant species, BRI has conducted research at various locations within the United States, particularly the northeastern U.S., as well as study sites in Central and South America, the Caribbean Islands, and China. With an overarching approach centered on the assessment of environmental stressors on wildlife health, BRI songbird studies are designed to advance scientific knowledge and to contribute valuable data to inform policy, assist in management decisions, and establish conservation initiatives for local, regional, and global songbird populations
Effect of Corn or Soybean Row Position on Soil Water
Crop plants can funnel water to the soil and increase water content more in the row relative to the interrow. Because the row intercepts more soil water after rains and higher root density, the soil may also dry out more between rains than does soil in the interrow. The objectives of this study were to determine if there is a row position difference in soil wetting after rain and drying between rains, and to determine the seasonal nature of these differences. The first experiment examined soil water content 0 to 0.06 m in row, interrow, and quarter corn row positions for eight sites at specific times during a corn (Zea mays L.)-growing season. During the growing season, the second experiment examined automated soil water measurements at one site for two corn years and one soybean (Glycine max [L.] Merr.) year at row and interrow positions to 0.15-m depth. Soil water content changes were significantly greater in the row than the interrow for some mid-season dates. Temporal soil water changes showed that row wetting and drying dominated over interrow soil water changes for mid season. The mean ratio of row/(row + interrow) soil water changes for wetting was 0.76 and 0.77 for corn and 0.64 for soybean and for drying was 0.58 and 0.84 for corn and 0.60 for soybean. Soybean showed the row effect for a shorter time of the season (up to 71 days) compared with corn (up to 159 days)
Cryptic species and parallel genetic structuring in Lethrinid fish:Implications for conservation and management in the southwest Indian Ocean
Analysis of genetic variation can provide insights into ecological and evolutionary diversification which, for commercially harvested species, can also be relevant to the implementation of spatial management strategies and sustainability. In comparison with other marine biodiversity hot spots, there has been less genetic research on the fauna of the southwest Indian Ocean (SWIO). This is epitomized by the lack of information for lethrinid fish, which support socioeconomically important fisheries in the region. This study combines comparative phylogeographic and population genetic analyses with ecological niche modeling to investigate historical and contemporary population dynamics of two species of emperor fish (Lethrinus mahsena and Lethrinus harak) across the SWIO. Both species shared similarly shallow phylogeographic patterns and modeled historical (LGM) habitat occupancies. For both species, allele frequency and kinship analyses of microsatellite variation revealed highly significant structure with no clear geographical pattern and nonrandom genetic relatedness among individuals within samples. The genetic patterns for both species indicate recurrent processes within the region that prevent genetic mixing, at least on timescales of interest to fishery managers, and the potential roles of recruitment variability and population isolation are discussed in light of biological and environmental information. This consistency in both historical and recurrent population processes indicates that the use of model species may be valuable in management initiatives with finite resources to predict population structure, at least in cases wherein biogeographic and ecological differences between taxa are minimized. Paradoxically, mtDNA sequencing and microsatellite analysis of samples from the Seychelles revealed a potential cryptic species occurring in sympatry with, and seemingly morphologically identical to, L. mahsena. BLAST results point to the likely misidentification of species and incongruence between voucher specimens, DNA barcodes, and taxonomy within the group, which highlights the utility and necessity of genetic approaches to characterize baseline biodiversity in the region before such model-based methods are employedpublishersversionPeer reviewe
Phylogeny of the Sepia officinalis species complex in the east Atlantic extends the known distribution of Sepia vermiculata across the Benguela upwelling region
Accurate species identification and biogeographic characterisation are fundamental for appropriate management of expanding cephalopod fisheries. This study addresses this topic within the common cuttlefish Sepia officinalis species complex (S. officinalis, S. hierredda and S. vermiculata), with an emphasis on occurrence in African waters. Tissue samples from the currently presumed distributions of S. vermiculata and S. hierredda (from South Africa and Ghana/Angola, respectively) were sequenced for the cytochrome c oxidase subunit I (COI) and the cytochrome b (cytb) genes of the mitochondrial genome and then compared to existing S. officinalis sequences. Three highly divergent and reciprocally monophyletic clades, corresponding to S. officinalis, S. hierredda and S. vermiculata, were resolved, representing the first molecular confirmation of the distinct species status of S. hierredda and S. vermiculata. The sequences also revealed that, contrary to expectations based on presently published information, all samples from southern Angola were S. vermiculata. These results indicate that the range of S. vermiculata extends beyond the currently described northern limit and that S. hierredda and S. vermiculata may be indiscriminately harvested in Angolan waters. Finer-scale patterns within S. vermiculata phylogeography also indicate that the Benguela Current System and/or other environmental factors serve to isolate northern and southern stocks
Deep phylogeographic structure may indicate cryptic species within the Sparid genus Spondyliosoma
Two geographically nonoverlapping species are currently described within the sparid genus Spondyliosoma: Spondyliosoma cantharus (Black Seabream) occurring across Mediterranean and eastern Atlantic waters from NW Europe to Angola and S. emarginatum (Steentjie) considered endemic to southern Africa. To address prominent knowledge gaps this study investigated range‐wide phylogeographic structure across both species. Mitochondrial DNA sequences revealed deep phylogeographic structuring with four regionally partitioned reciprocally monophyletic clades, a Mediterranean clade and three more closely related Atlantic clades [NE Atlantic, Angola and South Africa (corresponding to S. emarginatum)]. Divergence and distribution of the lineages reflects survival in, and expansion from, disjunct glacial refuge areas. Cytonuclear differentiation of S. emarginatum supports its validity as a distinct species endemic to South African waters
Deep phylogeographic structure may indicate cryptic species within the Sparid genus Spondyliosoma
The Predictive Safety Testing Consortium: safety bio-markers, collaboration, and qualification
The Predictive Safety Testing Consortium (PSTC) is one of nine consortia comprising the Critical Path Institute (C-Path), a non-profit organisation launched in 2005 and dedicated to playing the role of a catalyst in the development of new approaches that advance medical innovation and regulatory science. C-Path achieves this by lead-ing teams that share data, knowledge and expertise resulting in sound, consensus-based science. PSTC is a unique, public-private partnership that brings pharmaceutical companies together to share and validate safety testing methods under the advisement of worldwide regulatory agencies, including the US Food and Drug Administration (FDA), the European Medicines Agency (EMA), and the Japanese Pharmaceuticals and Medical Devices Agency (PMDA). The eighteen corporate members of PSTC share a common goal: to find improved safety testing methods and approaches utilizing fluid-based safety biomarkers which accurately predict drug-induced tissue injury. Specifically, the primary goal of PSTC is the qualification of novel translational safety biomarkers for use in early clinical trials in order to ena-ble safer investigations and development of new drug candidates. This manuscript describes the critical importance of improved safety biomarkers to the drug development process and the present state of the biomarker qualification process with regulatory agencies. In addition, the work that the PSTC and its collaborative partners have done and con-tinue to do to identify and qualify more selective and specific safety biomarkers is highlighted. Finally, successes in-cluding the recently adopted regulatory Letter of Support and ongoing efforts to better define the regulatory qualifica-tion process and an integrated translational safety strategy are also discussed
Deposition of mercury in forests across a montane elevation gradient: Elevational and seasonal patterns in methylmercury inputs and production
Global mercury contamination largely results from direct primary atmospheric and secondary legacy emissions, which can be deposited to ecosystems, converted to methylmercury, and bioaccumulated along food chains. We examined organic horizon soil samples collected across an elevational gradient on Whiteface Mountain in the Adirondack region of New York State, USA to determine spatial patterns in methylmercury concentrations across a forested montane landscape. We found that soil methylmercury concentrations were highest in the midelevation coniferous zone (0.39 ± 0.07 ng/g) compared to the higher elevation alpine zone (0.28 ± 0.04 ng/g) and particularly the lower elevation deciduous zone (0.17 ± 0.02 ng/g), while the percent of total mercury as methylmercury in soils decreased with elevation. We also found a seasonal pattern in soil methylmercury concentrations, with peak methylmercury values occurring in July. Given elevational patterns in temperature and bioavailable total mercury (derived from mineralization of soil organic matter), soil methylmercury concentrations appear to be driven by soil processing of ionic Hg, as opposed to atmospheric deposition of methylmercury. These methylmercury results are consistent with spatial patterns of mercury concentrations in songbird species observed from other studies, suggesting that future declines in mercury emissions could be important for reducing exposure of mercury to montane avian species.Key PointsTotal mercury and methylmercury concentrations and fluxes are examined across an elevational gradient on an Adirondack, New York mountainMethylmercury concentrations across the elevational gradient are greatest in midelevation coniferous zonesSoil methylmercury concentrations are driven by the internal processing of mercury, rather than external inputs of methylmercuryPlain Language SummaryOnce mercury is emitted into the atmosphere by anthropogenic sources, it can be deposited onto the Earth’s surface. This mercury can then be converted to its toxic form of methylmercury by microbes in the soil and can accumulate in birds, altering physiology, behavior, and reproduction. We examined soils from Whiteface Mountain in the Adirondack region of New York State, USA to determine patterns in the production of methylmercury. We found that methylmercury in soils was highest in the mid‐elevation coniferous forests of the mountain and that the concentration appeared to be driven by soil microbes rather than direct deposition of mercury from the atmosphere. The finding of peak methylmercury at mid‐elevations was consistent with previous studies showing peak bird mercury concentrations at the same elevation. Thus, reductions in methylmercury concentrations in these forests is important to reducing bird mercury concentrations.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138300/1/jgrg20832_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138300/2/jgrg20832-sup-0001-2016JG003721-SI.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138300/3/jgrg20832.pd
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