Do national advisories serve local consumers: an assessment of mercury in economically important North Carolina fish

Consumption of marine fish provides both benefits (lean protein, omega-3 fatty acids and essential nutrients) and risks (main source of mercury (Hg) exposure for humans). Mercury is a potent neurotoxin and the source of more fish advisories nationwide than any other toxicant. Despite the widespread nature of Hg, it is unknown whether local Hg contamination reflects national and regional levels often used as bases to inform consumers of potential fish consumption risk. Thus, the objectives of our study were to examine Hg levels of six commonly consumed marine species harvested locally off the North Carolina coast and to compare our results to published regional (Monterey Bay Aquarium's Seafood Watch List) and national (Environmental Protection Agency, EPA, and Food and Drug Administration, FDA) Hg averages, action levels, and guidelines. We found significant differences in Hg concentrations among collected species, and we identified correlations between Hg concentration and fish length and trophic levels. Collected mahi mahi and triggerfish were below the EPA fish tissue action level (0.3ppm). Wahoo and grouper exceeded the EPA action level but were below the FDA action level (1.0ppm). King mackerel had the highest Hg concentration among targeted species, exceeding both EPA and FDA action levels. Further, our local results were not always consistent with calculated averages from EPA and FDA databases for the same species, and although many of our findings were consistent with Monterey Bay Aquarium's Seafood Watch List (southeast region), recommendations based on Hg levels would conflict with recommendations they provide based on sustainability. We find regional and national averages are not always reflective of local Hg contamination and suggest local data may be needed to accurately assess consumer risk.     

Complete discrepancy between abnormal fetal karyotypes predicted by QF-PCR rapid testing and karyotyped cultured cells in a first-trimester CVS

A chorion villus sample (CVS) biopsied at 11 weeks' gestation for raised nuchal translucency, revealed monosomy X (presumptive 45,X karyotype) by QF-PCR for rapid aneuploidy testing for chromosomes 13, 18, 21, X and Y. Long-term culture gave the karyotype: 47,XY,+ 21[66]/49,XYY,+ 21,+ 21 [22]. This discrepancy prompted redigestion of the combined residual villus fragments from the original QF-PCR assay. The repeat QF-PCR assay identified the presence of trisomy 21 and a Y chromosome consistent with a 47,XY,+ 21 karyotype. A double non-disjunction event early in embryogenesis in a 47,XY,+ 21 conceptus with subsequent cell lineage compartmentalisation of the three observed cell lines (45,X; 47,XY,+ 21 and 49,XYY,+ 21,+ 21) would account for these results. This is the first reported case to describe complete discrepancy at diagnosis between abnormal karyotypes detected by QF-PCR rapid aneuploidy testing and a cultured karyotype in the same CVS. Copyright © 2006 John Wiley & Sons, Ltd.     

Local and Indigenous management of climate change risks to archaeological sites

Hundreds of thousands of significant archaeological and cultural heritage sites (cultural sites) along the coasts of every continent are threatened by sea level rise, and many will be destroyed. This wealth of artefacts and monuments testifies to human history, cosmology and identity. While cultural sites are especially important to local and Indigenous communities, a stall in coordinated global action means adaptation at a local scale is often unsupported. In response, this paper produces a practical climate change risk analysis methodology designed for independent, community-scale management of cultural sites. It builds on existing methods that prioritise sites most at risk from climate impacts, proposing a field survey that integrates an assessment of the relative cultural value of sites with assessment of exposure and sensitivity to climate impacts. The field survey also stands as a monitoring program and complements an assessment of organisational adaptive capacity. The preliminary field survey was tested by Indigenous land managers in remote northern Australia at midden and rock art sites threatened by sea level rise, extreme flood events and a range of non-climactic hazards. A participatory action research methodology—incorporating planning workshops, semi-structured interviews and participant observations—gave rise to significant modifications to the preliminary field survey as well as management prioritisation of 120 sites. The field survey is anticipated to have global application, particularly among marginalised and remote Indigenous communities. Well-planned and informed participation, with community control, monitoring and well-informed actions, will contribute significantly to coordinated global and regional adaptation strategies.     

The scale and cause of spatial heterogeneity in strength of temporal density dependence

The importance of density dependence in natural communities continues to spark much debate because it is fundamental to population regulation. We used temporal manipulations of density to explore potentially stabilizing density dependence in early survivorship among six local populations of a tropical damselfish (Dascyllus flavicaudus). Specifically, we tested the premise that spatial heterogeneity in the strength of temporal density dependence would reflect variation in density of predators, the agent of mortality. Our field manipulations revealed that mortality among successive cohorts of young fishes was density dependent at each reef, but that its strength varied by approximately 1.5 orders of magnitude. This spatial heterogeneity was well predicted by variation among the six reefs in the density of predatory fishes that consume juvenile damselfishes. Because density dependence arose from competition for enemy-free space within a shelter coral, the mortality consequence of the competition depended on the neighborhood density of predators. Thus, the scale of heterogeneity in the density dependence largely reflected attributes of the environment that shaped the local abundance of predators. These results have important implications for how ecologists explore regulatory processes in nature. Failure to account for spatial variation could frequently yield misleading conclusions regarding density dependence as a stabilizing process, obscure underlying mechanisms influencing its strength, and provide no insight into the spatial scale of the heterogeneity. Further, models of population dynamics will be improved when experimental approaches better estimate the magnitude and causes of variation in strength of stabilizing density dependence.     

Coastal retreat and/or advance adjacent to defences in England and Wales

Retreat and advance of shoreline position occurs naturally, and also as a result of defences which are constructed to prevent erosion and flooding. Retreat more commonly manifests itself down-drift of defences due to a sediment deficit causing the coast to become ‘set-back’. Advance normally develops due to sediment accumulation up-drift of a barrier inhibiting longshore drift, resulting in the coast becoming ‘set-forward’. Many examples of set-backs and set-forwards are recorded, but their location, number and cause is not known on a national scale. Using the Futurecoast aerial photographs, approximately 200 localities were identified as set-back or set-forward in England and Wales, with half situated in the Eastern and South East regions of England. Half of the total set-backs or set-forwards were on cliffed coasts, and half on low-lying coasts. Without local knowledge it is difficult to distinguish between set-backs and set-forwards. Set-backs often indicate higher retreat rates, thus threatening cliff-top infrastructure which requires defence upgrade and extensions, as well as raising maintenance costs. Monitoring set-backs is important for shoreline management, because as retreat continues, set-backs evolve and artificial headlands form and grow. This is reinforced by the shift from hard defence policies towards softer engineering approaches, managed realignment and limited intervention.     

Genetic structure of the southeastern United States loggerhead turtle nesting aggregation: evidence of additional structure within the peninsular Florida recovery unit

The southeastern United States supports one of two large loggerhead turtle (Caretta caretta) nesting aggregations worldwide and is therefore critical to global conservation and recovery efforts for the species. Previous studies have established the presence of four demographically distinct nesting populations (management units) corresponding to beaches from (1) North Carolina through northeastern Florida, (2) peninsular Florida, (3) the Dry Tortugas, and (4) northwest Florida. Temporal and geographic genetic structure of the nesting aggregation was examined utilizing partial mitochondrial control region haplotype frequencies from 834 samples collected over the 2002 through 2008 nesting seasons from 19 beaches as well as previously published haplotype data. Most rookeries did not exhibit interannual genetic variation. However, the interannual variation detected did significantly impact the interpretation of spatial genetic structure in northeastern Florida. Based on pairwise F _ST comparisons, exact tests of population differentiation, and analysis of molecular variance, the present study upholds the distinctiveness of the four currently recognized management units and further supports recognition of discrete central eastern, southern (southeastern and southwestern), and central western Florida management units. Further subdivision may be warranted, but more intensive genetic sampling is required. In addition, tools such as telemetry and mark-recapture are needed to complement genetic data and overcome limitations of genetic markers in resolving loggerhead turtle rookery connectivity in the southeastern USA.     

Measuring in-cabin school bus tailpipe and crankcase PM2.5: a new dual tracer method

Exposures of occupants in school buses to on-road vehicle emissions, including emissions from the bus itself, can be substantially greater than those in outdoor settings. A dual tracer method was developed and applied to two school buses in Seattle in 2005 to quantify in-cabin fine particulate matter (PM2.5) concentrations attributable to the buses' diesel engine tailpipe (DPMtp) and crankcase vent (PMck) emissions. The new method avoids the problem of differentiating bus emissions from chemically identical emissions of other vehicles by using a fuel-based organometallic iridium tracer for engine exhaust and by adding deuterated hexatriacontane to engine oil. Source testing results showed consistent PM:tracer ratios for the primary tracer for each type of emissions. Comparisons of the PM:tracer ratios indicated that there was a small amount of unburned lubricating oil emitted from the tailpipe; however, virtually no diesel fuel combustion products were found in the crankcase emissions. For the limited testing conducted here, although PMck emission rates (averages of 0.028 and 0.099 g/km for the two buses) were lower than those from the tailpipe (0.18 and 0.14 g/km), in-cabin PMck concentrations averaging 6.8 microg/m3 were higher than DPMtp (0.91 microg/m3 average). In-cabin DPMtp and PMck concentrations were significantly higher with bus windows closed (1.4 and 12 microg/m3, respectively) as compared with open (0.44 and 1.3 microg/m3, respectively). For comparison, average closed- and open-window in-cabin total PM2.5 concentrations were 26 and 12 microg/m3, respectively. Despite the relatively short in-cabin sampling times, very high sensitivities were achieved, with detection limits of 0.002 microg/m3 for DPMtp and 0.05 microg/m3 for PMck.     

Recent trends and projections of primary NO2 emissions in Europe

An assessment of recent trends in primary NO₂ emissions has been carried out for ten case study locations across the European Union. Estimates of the percentage of NO_x from road traffic emitted as primary NO₂ (f-NO₂) have been derived for 1995, 2000 and 2005 by combining the results of a literature survey of primary NO₂ emission factors for different vehicle types and technologies with an emission inventory. Estimates of f-NO₂ have also been derived from ambient monitoring data at roadside sites in each case study location using a model.The results of the analysis of trends show that f-NO₂ has increased in recent years and that the rate of increase has been greatest since 2000. f-NO₂ has increased from 8.6% in 2000 to 12.4% in 2004 as an average across the monitoring sites and from an average of 6.3% in 2000 to 10.6% in 2005 as an average of the emission inventory based calculations for the case study countries. f-NO₂ is predicted to increase further to an average of 19.6% in 2010 and 32.0% in 2020 as a result of the further penetration of exhaust after treatment technologies for diesel vehicles in the fleets. This increase is expected to be offset by the large reduction in NO_x emissions over this period, resulting in an increase in NO₂ emissions from road traffic to 2015, followed by a decline to close to 2004 levels by 2020. Estimates of future ambient NO₂ concentrations have also been calculated for the roadside monitoring sites included in the study. At 29 out of 45 of these sites the annual mean NO₂ limit value is predicted to be exceeded in 2010. At 22 of these sites, the annual mean concentration is expected to remain above the limit value until 2020 and beyond.     

Integrating “livelihoods” into integrated water resources management: taking the integration paradigm to its logical next step for developing countries

This paper examines the weaknesses in the current understanding of Integrated Water Resources Management (IWRM) from the perspective of livelihoods. Empowering poor people, reducing poverty, improving livelihoods, and promoting economic growth ought to be the basic objectives of IWRM. But as currently understood and used, IWRM often tends to focus on second-generation issues such as cost recovery, reallocation of water to higher value uses, and environmental conservation. This paper argues that IWRM needs to be placed in the broader context of both modern Integrated Natural Resource Management (INRM) and the livelihoods approach, which together take a holistic and people-centered approach. The paper concludes with an alternative definition of IWRM as involving the promotion of human welfare, especially the reduction of poverty, encouragement of better livelihoods and balanced economic growth through effective democratic development and management of water and other natural resources in an integrated multilevel framework that is as equitable, sustainable, and transparent as possible, and conserves vital ecosystems. Transparent user-friendly information and models for assisting decision making are essential features of livelihood-oriented IWRM.     

Preliminary Studies on Converting Agricultural Waste into Biodegradable Plastics,Part I: Corn Distillers’ Dry Grain

Distillers dry grain (DDG) was derivatized either by carboxymethylation, glutaration, maleiation, phthallation, or succination in order to produce anionic materials suitable for complexation with soy protein isolate. Infrared spectroscopy confirmed that derivatization of DDG by all reagents was successful. Blending of derivatized anionic products with soy protein resulted in instant precipitation of gels. The gels were centrifuged, molded, and dried into solid pellets with tensile strengths as high as 1.67MPa, suggesting that these materials could be promising as biodegradable structural materials. Infrared spectroscopy suggested the possibility of complexes forming between soy protein isolate and each of the derivatized DDG samples.