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961.
Given the threats of greenhouse gas emissions and a changing climate to marine ecosystems, there is an urgent need to better understand the response of not only adult corals, which are particularly sensitive to environmental changes, but also their larvae, whose mechanisms of acclimation to both temperature increases and ocean acidification are not well understood. Brooded larvae from the reef coral Pocillopora damicornis collected from Nanwan Bay, Southern Taiwan, were exposed to ambient or elevated temperature (25 or 29 °C) and pCO2 (415 or 635 μatm) in a factorial experiment for 9 days, and a variety of physiological and molecular parameters were measured. Respiration and rubisco protein expression decreased in larvae exposed to elevated temperature, while those incubated at high pCO2 were larger in size. Collectively, these findings highlight the complex metabolic and molecular responses of this life history stage and the need to integrate our understanding across multiple levels of biological organization. Our results also suggest that for this pocilloporid larval life stage, the impacts of elevated temperature are likely a greater threat under near-future predictions for climate change than ocean acidification.  相似文献   
962.
Spatial variogram estimation from temporally aggregated seabird count data   总被引:1,自引:0,他引:1  
Seabird abundance is an important indicator for assessing impact of human activities on the marine environment. However, data collection at sea is time consuming and surveys are carried out over several consecutive days for efficiency reasons. This study investigates the validity of aggregating those data over time to estimate a spatial variogram that is representative for spatial correlation in species abundance. For this purpose we simulate four-day surveys of seabird count data that contain spatial and temporal correlation arising from temporal changes in the spatial pattern of environmental conditions. Estimates of the aggregated spatial variogram are compared to a variogram that would arise when data were collected over a single day. The study reveals that, under changing environmental conditions over surveys days, aggregating data over a four-day survey increases both the non-spatial variation in the data and the scale of spatial correlation in seabird data. Next, the effect of using an aggregated variogram on the statistical power to test the significance of an impact is investigated. The impact concerns a case of establishing an offshore wind farm resulting in seabird displacement. The study shows that both overestimation and underestimation of statistical power occurs, with power estimates differing up to a factor of two. We conclude that the spatial variation in seabird abundance can be misrepresented by using temporally aggregated data. In impact studies, such misrepresentation can lead to erroneous assessments of the ability to detect impact.  相似文献   
963.
Post-settlement events can significantly alter the density distribution of settlers and subsequently the adult population structure. The temporal and inter-annual variability of settlement and the effects of mortality on recruitment were investigated across 2 years in the vicinities of Cabo de Palos–Islas Hormigas Marine Reserve by visual census and light trap sampling. Settlement was seasonal with greater species richness and abundance in summer. Although temporal synchronization was observed between larval supply and settlement, densities of settlers could not be predicted from post-larval abundances. Timing of settlement was consistent between years but with high inter-annual variation in abundance. High mortality (~80 %) and general decoupling between post-larval and settlement stages suggest that early mortality is driving such patterns. Nevertheless, indications of habitat-mediated mortality were found for benthic species such as Symphodus and Diplodus, highlighting the importance of habitat in shaping population demography.  相似文献   
964.
965.
C25 highly branched isoprenoids (HBIs) are produced by a relatively small number of diatom species, yet are common constituents of almost all marine environments. Previously, detection of HBIs in a few aquatic Arctic animals has indicated the potential use of these lipids for providing novel ecological information. In the current study, analysis of lipid extracts of livers from Leach’s storm petrel (Oceanodroma leucorhoa) and Brunnich’s guillemot (Uria lomvia) facilitated identification and quantification of HBI isomers. HBIs were found in the tissues of all specimens with clear differences in the abundances and distributions of individual HBI isomers both between Atlantic as well as Arctic birds. These differences are consistent with contrasting oceanographic regimes and suggests that regional differences in HBIs are reflected in the tissues of consumers. Tissue-specific assessment of HBI distributions has also revealed the presence of these lipids in muscle for the first time. This study represents the first report of HBI lipids in birds and provides evidence that these lipids are transferred across trophic levels and extends their potential use as chemical tracers beyond the ecology of aquatic organisms.  相似文献   
966.

Purpose

Ammophila arenaria (marram grass) may invade remote beach-dune systems by the marine dispersal of rhizomes. In New Zealand, and elsewhere, the conservation of the remaining dune systems of high conservation value would be advanced by predicting where this species might successfully establish and undertaking appropriate surveillance. This paper examines the ability of A. arenaria to sustain growth in the stressful back-beach environment.

Methods

Shoots developed from rhizomes were subjected to burial, depth, salt spray and desiccation treatments in the glasshouse. Plants were also subjected to salt water inundation. Two field populations of A. arenaria were surveyed for a period of almost 3 years, following rhizome stranding in July 2007.

Results

Shoots were able to emerge from depths of up to 40 cm. Rhizomes failed to produce shoots when the moisture content of rhizomes was less than 18.25 %, which occurred after 3 days of drought. The survival of buried plants was significantly reduced compared to non-buried plants when burial exceeded 80 % of the plant height. No plants survived when burial exceeded 100 % of the plant height. No tillers survived without water for more than 3 weeks. Exposure to salt spray had no effect on shoot survival. Immersion in seawater significantly reduced survival—exposure to seawater, equivalent to only one high tide immersion event, was sufficient to reduce plant survival in the glasshouse.

Conclusions

Burial, desiccation and salt-spray may, on occasion, be responsible for either preventing the regeneration of A. arenaria rhizomes or limiting the survival of the resultant plants, but exposure to wave activity determines the viability of a population.  相似文献   
967.
Efficient planning for LNG berths used by modern generation vessels needs a high level and accumulation of experiences. The planning process should cover the main components for the handling berth as berthing dolphins, mooring dolphins, berthing platform and suitable type of fenders. The planning and design should cover studying all the design forces that affect these items, including the hidden capacities. This efficient planning should cover two international standards. The first is the British standard (BS) and the second one is the (OCIMF, Oil Companies International Marine Forum) international standards for the petroleum companies forum. Applying the specifications for these two standards together, the efficient planning for LNG berths can be obtained. This research deals with that planning details in a simplified procedure, which is easy to follow.  相似文献   
968.
Vulnerability assessment is one of the methods currently being used to measure the ocean and coastal sustainability in order to enable better evaluation and redesign of land-based development and policy-making. Because of different geological and geographical formations, the elements that comprise the vulnerability indicators are different from each other, and there are various vulnerability equations that have been used. At the present time, there are no unified vulnerability indicators that can be applied universally to every country. The Seribu Islands, Indonesia, also known in English as the Thousand Islands, consisting of 105 islands located to the north of Jakarta, have been chosen as a study area for vulnerability assessment according to the basic principles of Integrated Coastal Zone Management theory. The results indicate that in practice, Indonesian Integrated Coastal Zone Management legal systems do exist and that in some cases, part of the responsibility for the problems rests with legislation that imposes complex systems of administration, unrealistic sanctions and impractical solutions. This research also shows that inter-sectoral, inter-governance and spatial developments are the three components that need to be improved for the successful implementation of Integrated Coastal Zone Management in the region.  相似文献   
969.
The risk from potentially toxic elements in playground soils is of concern to children’s health as a result of the potential for intentional or unintentional consumption. Current approaches, based on total potentially toxic element concentration, may overestimate the risk. This has resulted in the development and use of in vitro gastrointestinal extraction protocols. The concentration of arsenic (As) and lead (Pb) in soils collected from 12 schools in north-east England has been compared with Soil Guideline Values from seven countries as well as reported literature concentrations for playgrounds and recreational parks. It was found that the mean As concentration of 14.1 ± 5.4 mg/kg does not exceed the England residential Soil Guideline Value in any location, while the mean Pb concentration of 298 ± 380 mg/kg is high but not excessive. Both concentrations have been assessed using the maximum potential daily intake from soil that a child could ingest. Based on this protocol Pb does not exceed the tolerable daily intake in any playground location, while As is generally 10 times lower than the oral index dose in the majority of playgrounds. The oral bioaccessibility of As and Pb was investigated. It was concluded that the highest concentrations were determined in the gastric phase with maximum bioaccessibilities of 54 and 46 % for As and Pb, respectively. Here we have demonstrated that minimal risk arises from the investigated playgrounds provided that good personal hygiene is adhered to.  相似文献   
970.
Imposex and decline in reproductive output in marine gastropods have been linked to tributyltin (TBT) exposure. This study describes Chesapeake Bay, USA, veined rapa whelk Rapana venosa imposex incidence and sex ratios from 1998 to 2009. Tissue TBT concentrations (ng g?1) were examined with respect to whelk sex, size, and water temperature at the time of collection, and also to egg case size, hatching success, and veliger diameter. Imposex incidence declined and population sex ratios moved closer to parity from 1998 to 2009. Observed TBT concentrations (ng g?1) were higher in James River than in Ocean View whelks with higher TBT concentrations observed in males than in females. Exponential declines in TBT concentrations from female-specific first to last clutches within a reproductive season were observed, indicating that whelks depurate TBT through egg case deposition. Egg capsule hatching success and veliger size were similar for female and imposex whelks. The R. venosa imposex levels observed in Chesapeake Bay apparently do not affect the production, release, or viability of larvae.  相似文献   
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