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211.
Control or rescue at sea? Aims and limits of border surveillance technologies in the Mediterranean Sea
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Maria Gabrielsen Jumbert 《Disasters》2018,42(4):674-696
The matter of boat migrants crossing the Mediterranean Sea, seeking to reach Europe, is interchangeably defined as a ‘security issue', requiring stricter border controls, and as a humanitarian issue with corresponding rescue and protection requirements. This paper seeks to understand what role various surveillance technologies, such as radar, satellites, and unmanned aerial vehicles, can play in this respect (legally and technically), in comparison to the role that they are assigned (that is, political expectations). To unravel what surveillance technologies can and cannot do vis‐à‐vis the aims of control and rescue, there is a need to comprehend what information can be collected and what information is needed to fulfil these objectives. The paper contends that there is a mismatch between the information sought to ‘control’ borders, but which cannot be gathered effectively by or processed using surveillance technologies, and the valuable information needed to perform rescue operations, which these surveillance technologies can supply. 相似文献
212.
Amy C. Dolan Michael T. Murphy Lucas J. Redmond Debbie Duffield 《Behavioral ecology and sociobiology》2009,63(10):1527-1537
Sex allocation theory predicts that if variance in reproductive success differs between the sexes, females who are able to
produce high-quality young should bias offspring sex ratio towards the sex with the higher potential reproductive success.
We tested the hypothesis that high-quality (i.e., heavy) female eastern kingbirds (Tyrannus tyrannus) that bred early in the breeding season would produce male-biased clutches. A significant opportunity for sexual selection
also exists in this socially monogamous but cryptically polygamous species, and we predicted that successful extra-pair (EP)
sires would be associated with an excess of male offspring. Although population brood sex ratio did not differ from parity,
it increased significantly with female body mass and declined with female breeding date, but was independent of the morphology
and display (song) behavior (correlates of reproductive success) of social males and EP sires. Male offspring were significantly
heavier than female offspring at fledging. Moreover, the probability that male offspring were resighted in subsequent years
declined with breeding date, and was greater in replacement clutches, but lower when clutch size was large. Probability of
resighting female offspring varied annually, but was independent of all other variables. Given that variance in reproductive
success of male kingbirds is much greater than that of females, and that male offspring are more expensive to produce and
have a higher probability of recruitment if fledged early in the season, our results support predictions of sex allocation
theory: high-quality (heavy) females breeding when conditions were optimal for male recruitment produced an excess of sons. 相似文献
213.
Giovanni Randazzo Massimo Lo Curzio Stefania Lanza 《Journal of Coastal Conservation》2008,12(3):161-168
The Industrial District (I.D.) of Messina was the first public authority to consider useful the application of the Strategic
Environmental Assessment (SEA) procedure for the development of an Industrial Plan regarding a coastal area. At the moment
the I.D. includes six areas, but the application of the SEA concerns only the area of Pace del Mela (along the north-eastern
coast of Sicily), where a “District of the two Seas” will be created, based on the synergetic development between an industrialized
niche (shipbuilding) and touristic development (port and hotels). The area in which this type of intervention will occur is
not in use at the moment and it was not possible to collect environmental data. For this reason, in order to describe the
environmental features of this territory, we took into consideration a few indicators which could be easily identified, necessary
for a post evaluation which considers the Environmental Impact Assessment (EIA) of the industrial and suburban structures
to be built. 相似文献
214.
Marine protected areas (MPAs) are critical to the well-being of threatened ecosystems and thus can be highly beneficial to humans, especially to those residing nearby. We explore the qualities of 117 MPAs in the Mediterranean basin and develop a taxonomy of their characteristics. We relate the spatial distribution of the MPAs to the various characteristics of the taxonomy (size, distance from shore, protection levels, management regimes, etc.) and to areas of high human impact and influence levels. To do this we use information on biogeographic regions and information from two different human influence models; one model developed for the marine environment and one covering the littoral terrestrial environment. Our analysis provides insights to planners and managers working in a regional capacity and trying to build MPA networks. Generally, current MPAs have not been established in high impact areas despite their being close to shores containing intense human activity. Decision-makers wishing to design and establish new MPAs may seek out areas of high cumulative human impacts (near the marine-terrestrial interface) or avoid them depending on marine conservation objectives, including the desire to vary types of MPAs within a network. Limitations of our analysis and methodology indicate areas for further research. 相似文献
215.
Mariella Tataranni Claudio Lardicci 《Environmental pollution (Barking, Essex : 1987)》2010,158(1):26-34
The aim of this study was to analyse the variability of four different benthic biotic indices (AMBI, BENTIX, H′, M-AMBI) in two marine coastal areas of the North-Western Mediterranean Sea. In each coastal area, 36 replicates were randomly selected according to a hierarchical sampling design, which allowed estimating the variance components of the indices associated with four different spatial scales (ranging from metres to kilometres). All the analyses were performed at two different sampling periods in order to evaluate if the observed trends were consistent over the time. The variance components of the four indices revealed complex trends and different patterns in the two sampling periods. These results highlighted that independently from the employed index, a rigorous and appropriate sampling design taking into account different scales should always be used in order to avoid erroneous classifications and to develop effective monitoring programs. 相似文献
216.
Liver of blue shark (Prionace glauca) specimens from the South-Eastern Mediterranean Sea were analyzed for the presence of polychlorinated biphenyls (PCBs), including coplanar congeners, polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). PCBs were the dominant chemicals, followed by PCDFs and PCDDs. The pattern of PCB congener concentrations in the hepatic tissue was dominated by higher chlorinated compounds. The specific profile of toxic PCDD/F congeners was characterized mainly by 2,3,7,8-TCDF and 2,3,7,8-TCDD, followed by 1,2,3,6,7,8-HxCDD and 2,3,4,6,7,8-HxCDF. The total 2,3,7,8-TCDD toxic equivalent (TEQs) was 149 pg g−1 lipid wt. The profile of TEQ shows that PCDDs present the greatest risk to this species contributing to total toxicity with a percentage approximately of 60%, while the contribution of PCDFs and DL-PCBs is almost the same being 22.4% and 21.6%, respectively. Further investigations are urgently needed to characterize the PCDD/Fs contamination levels not only in elasmobranch fish but in all Mediterranean marine biota. 相似文献
217.
Aquatic farming has been considered, during the last decades, as the fastest growing food production industry powered by governmental and technological impulsion. Compensation for fisheries decline, creation of new jobs and source of financial windfall are the most important benefits. However, similar to most of the human food-production activities, aquaculture raised several issues related to the environmental welfare and consumer safety. An effort to record the aquaculture-environment and -human safety interactions with regard to the Mediterranean mariculture, is attempted herein. We focused on this geographical area due to its individualities in both the hydrological and physicochemical characteristics and the forms of aquaculture activities. The cage farming of euryhaline marine fish species and more recently of bluefin tuna and mollusk farming are the dominating aquaculture activities. The impacts of these activities to the environment, through wastes offloads, introduction of alien species, genetic interactions, disease transfer, release of chemicals, use of wild recourses, alterations of coastal habitats and disturbance of wildlife, are analytically considered. Also the consumer safety issues related to the farming are assessed, including generation of antibiotic-resistant microorganisms, contaminants transferred to humans though food chain and other hazards from consumption of aquacultured items. Within these, the major literature findings are critically examined and suggestions for scientific areas that need further development are made. The major tasks for future aquaculture development in this region are: (i) to ensure sustainability and (ii) to balance the risks to public or environmental health with the substantial economical benefits. In regard with monitoring, tools must be created or adapted to predict the environmental costs and estimate consumer impact. At a canonistic and legal basis, the establishment of appropriate legal guidelines and common policies from all countries involved should be mandatory. 相似文献
218.
Heimbürger LE Migon C Cossa D 《Environmental pollution (Barking, Essex : 1987)》2011,159(6):1629-1634
Under stratified oligotrophic conditions (May-November), the surface mixed layer of the Northwestern Mediterranean constitutes a homogeneous water volume of 10-30 m depth. In other respects, the mean residence time of Ligurian surface waters (0-200 m) is 102 days. It is therefore possible to quantify the extent to which atmospheric deposition of trace metals affects surface waters. On the basis of literature data on anthropogenic and natural trace metals, we demonstrate that the ratios between total seawater labile atmospheric deposition during 102 days (Δc) and dissolved TM concentrations in Ligurian surface waters (c) illustrate the impact of atmospheric deposition on surface seawater (Δc/c). High ratios indicate surface TM enrichments, while low ratios indicate surface TM depletion, due to the quasi-complete sorption and removal of TMs by plankton during spring bloom. The simple box model proposed here may be used for other marine regions where hydrodynamical and physico-chemical constraints are well defined. 相似文献
219.
Over the past century, the Venice lagoon has experienced a high rate of wetland loss and a strong net export of sediments;
currently the local Authority is running several projects for beneficial use of dredging materials. From March 1993 until
March 1995 the accretionary response of wetlands in the lagoon to changing water levels was studied. Vertical accretion, short
term sedimentation and surface elevation change were measured at six sites with varying sediment availability and wave energy.
Short term sedimentation averaged 6.85 g m−2 d−1 with a minimum of 0.06 g and a maximum of 72 g during periods of high tides and storms. Over two years accretion ranged from
0.3 to 2.3 cm/yr and surface elevation change ranged from+0.7 to −3.7 cm/yr. The sites with highest accretion were near a
river mouth and a site with strong wave energy and rapid erosion of the marsh edge with a high resuspended sediment availability.
The rate of accretion at three sites was clearly sufficient to offset relative sea level rise, but a saline site with low
sediment availability had the lowest accretion. A sediment fence significantly increased accretion at one site. The results
suggest that reduction of turbulent motion or increasing sediment availability are needed to offset wetland loss in different
areas of the lagoon. 相似文献
220.
Eels are exposed to pollutants due to their unusual life cycle and are vulnerable to contamination associated with sediment
due to their diet, feeding habits and territoriality. Since the 1980s, a decline in American and European eel populations
has been recorded. The causes of this decline still are unknown but pollution from domestic and industrial effluents is known
to be involved. Since little data is available on PCB contamination in eels from Italian waters, PCBs were measured in muscle
of Anguilla anguilla captured in 2001 in two brackish ecosystems of the Mediterranean: the lagoons of Orbetello and Santa Giusta (Italy). PCBs
were higher in samples from Orbetello lagoon than in those detected from Santa Giusta lagoon (P < 0.05). Congener and isomer analyses indicated Aroclor 1260 as a likely source of PCBs in the Orbetello and Santa Giusta
samples. Only the toxic equivalents (TEQs) of mono-ortho PCBs were calculated. 相似文献