The destruction of coral reef habitats has occurred at unprecedented levels during the last three decades. Coral disease and bleaching in the Caribbean and South Florida have caused extensive coral mortality with limited recovery, often coral reefs are being replaced with turf algae. Acroporids were once dominant corals and have diminished to the state where they are being considered as endangered species. Our survey assessed the condition of reef corals throughout South Florida. A probability-based design produced unbiased estimates of the spatial extent of ecological condition, measured as the absence or presence and frequency or prevalence of coral diseases and bleaching intensity over large geographic regions. This approach allowed us to calculate a quantifiable level of uncertainty. Coral condition was estimated for 4100 hectares (ha) (or 41.0 km2) of coral reefs in South Florida, including reefs in the Florida Keys National Marine Sanctuary (FKNMS), New Grounds, Dry Tortugas National Park (DTNP), and Biscayne National Park (BNP). The absence or presence of coral disease, causal coral bleaching, partial bleaching and coral paling were not good indicators of overall coral condition. It was more useful to report the prevalence of anomalies that indicated a compromised condition at both the population and community levels. For example, 79% of the area in South Florida had less than 6% of the coral colonies diseased, whereas only 2.2% (97.15 ha) of the sampled area had a maximum prevalence of 13% diseased coral colonies at any single location. The usefulness of causal bleaching might be more important when considering the prevalence of each of the three different states at a single location. For example, paling was observed over the entire area, whereas bleaching and partial bleaching occurred at 19 and 41% of the area, respectively. An index for coral reef condition might integrate the prevalence and species affected by each bleaching state at individual locations. By establishing these baselines, future surveys can examine changes and trends in the spatial distribution of coral conditions in South Florida and able to score the reefs as to their health status. 相似文献
Shellfish samples (n = 310) purchased from local supermarkets were analysed for the presence of hepatitis E virus (HEV) by nested RT-PCR and real-time qRT-PCR. Overall, 2.9% of samples tested positive for the presence of HEV. Phylogenetic analysis of HEV sequences revealed all as being genotype 3 HEV. This is the first report of the detection of HEV in commercially sold shellfish in Scotland. These findings may encourage further research that will help address the gaps in the knowledge in respect to foodborne transmission of HEV in Scotland and the rest of the United Kingdom. 相似文献
Greenhouse gas (GHG) inventories at national or provincial levels include the total emissions as well as the emissions for many categories of human activity, but there is a need for spatially explicit GHG emission inventories. Hence, the aim of this research was to outline a methodology for producing a high-resolution spatially explicit emission inventory, demonstrated for Poland. GHG emission sources were classified into point, line, and area types and then combined to calculate the total emissions. We created vector maps of all sources for all categories of economic activity covered by the IPCC guidelines, using official information about companies, the administrative maps, Corine Land Cover, and other available data. We created the algorithms for the disaggregation of these data to the level of elementary objects such as emission sources. The algorithms used depend on the categories of economic activity under investigation. We calculated the emissions of carbon, nitrogen sulfure and other GHG compounds (e.g., CO2, CH4, N2O, SO2, NMVOC) as well as total emissions in the CO2-equivalent. Gridded data were only created in the final stage to present the summarized emissions of very diverse sources from all categories. In our approach, information on the administrative assignment of corresponding emission sources is retained, which makes it possible to aggregate the final results to different administrative levels including municipalities, which is not possible using a traditional gridded emission approach. We demonstrate that any grid size can be chosen to match the aim of the spatial inventory, but not less than 100 m in this example, which corresponds to the coarsest resolution of the input datasets. We then considered the uncertainties in the statistical data, the calorific values, and the emission factors, with symmetric and asymmetric (lognormal) distributions. Using the Monte Carlo method, uncertainties, expressed using 95% confidence intervals, were estimated for high point-type emission sources, the provinces, and the subsectors. Such an approach is flexible, provided the data are available, and can be applied to other countries.
We measured an array of biophysical and spectral variables to evaluate the response and recovery of Spartina alterniflora to a sudden dieback event in spring and summer 2004 within a low marsh in coastal Virginia, USA. S. alterniflora is a foundation species, whose loss decreases ecosystem services and potentiates ecosystem state change. Long-term records of the potential environmental drivers of dieback such as precipitation and tidal inundation did not evidence any particular anomalies, although Hurricane Isabel in fall 2003 may have been related to dieback. Transects were established across the interface between the dieback area and apparently healthy areas of marsh. Plant condition was classified based on ground cover within transects as dieback, intermediate and healthy. Numerous characteristics of S. alterniflora culms within each condition class were assessed including biomass, morphology and spectral attributes associated with photosynthetic pigments. Plants demonstrated evidence of stress in 2004 and 2005 beyond areas of obvious dieback and resilience at a multi-year scale. Resilience of the plants was evident in recovery of ground cover and biomass largely within 3 y, although a small remnant of dieback persisted for 8 y. Culms surviving within the dieback and areas of intermediate impact had modified morphological traits and spectral response that reflected stress. These morphometric and spectral differences among plant cover condition classes serve as guidelines for monitoring of dieback initiation, effects and subsequent recovery. Although a number of environmental and biotic parameters were assessed relative to causation, the reason for this particular dieback remains largely unknown, however. 相似文献
The Benguela Current Large Marine Ecosystem off southwest Africa is a regionally valued system because of its biological productivity, which supports high biomass throughout the foodweb, and a rich diversity of habitats and species. However, the region is exposed to numerous anthropogenic pressures that are likely to escalate under future economic growth. In response, the Benguela Current Commission called for a spatial biodiversity assessment (BCC-SBA) to identify conservation priorities, including potential areas for marine protected areas. The systematic conservation-planning approach to this assessment requires a fine-scale map of coastal habitats, which was not previously available for the region. Our aim was to undertake this mapping, within tight logistic and resource limitations. We used a previously derived methodology for mapping the distribution of coastal habitats from aerial imagery. The Benguela coast is approximately 5,047 km long. Half of this extent is sandy beach, a third is rocky and mixed shores, 13 % comprises lagoonal features, and the remainder (4 %) comprises estuaries and offshore islands. The distribution and extent of these coastal habitats differs substantially alongshore (i.e. with latitude), with conditions ranging north–south from hot, humid mangrove-lined lagoons, to hyper-arid coastal desert sandy beaches. Patterns in regional geology, climate and oceanography are proposed as the main drivers of spatial heterogeneity in coastal habitat types. The resulting ecological and socio-economic wealth requires proactive protection (supported through the BCC-SBA, for example), to ensure sustainable utilization of the rich natural resources, and persistence of these resources for the benefit of current and future generations. 相似文献
There is mounting evidence in a variety of taxa that females increase offspring quality by mating with multiple males, often
resulting in multiple paternity. In birds, however, few studies have explicitly examined the benefits of mating with several
different males; instead, the focus has been on whether or not extra-pair mating occurs, and its adaptive significance remains
controversial. We examined the hypothesis that offspring quality, particularly immune response (phytohaemagglutinin assay)
and growth, increases with the number of sires in broods of socially monogamous tree swallows (Tachycineta bicolor). We found one of the highest known levels of multiple paternity in birds (84% of nests with two or more extra-pair young
had at least two extra-pair sires). Among nests with extra-pair young, the number and diversity of sires continued to increase
linearly with the number of extra-pair young, so there was no evidence that some males monopolized paternity at high levels
of extra-pair fertilization. Indeed, the number of sires was actually greater than expected in large broods, suggesting that
some females might be seeking more mates. We found no effect of the number of sires on nestling immune response or growth.
In mixed paternity broods, the immune response of extra-pair young did not differ from that of their within-pair half-siblings.
However, among all broods, nestlings had a stronger immune response in nests with at least one extra-pair nestling than in
nests with all within-pair nestlings. These results are not consistent with a good genes benefit of extra-pair mating, but
they do suggest that there are environmental effects associated with extra-pair mating that increase nestling immune response.
These environmental effects could produce indirect genetic effects on sexual selection if they are heritable. The extraordinarily
high number of sires in this species highlights a relatively unexplored source of sexual selection in birds. 相似文献