An experiment was undertaken at Farol Island, Brazil, to examine colonization of bare aluminium surfaces by microbes and meiofauna.
It was hypothesized that a primary source of meiofaunal colonists was sediment resuspended during upwelling events, two of
which occurred during the experiment. Microbial biofilms formed on the experimental substrata within 1 day, and continued
to develop throughout the experimental period. Among meiofaunal groups copepods also appeared on the first day, and nematodes
on the second. Meiofaunal community structure developed in three main phases: an initial phase of 2 days, characterized by
low abundances of copepods; a second phase during the first upwelling period characterized by higher abundances of copepods
and also by turbellarians; and a third phase from day 13 onwards characterized by relatively stable abundances of a range
of taxa including copepods, cirripedes, nematodes and ostracods. Nematode assemblages also developed in three phases, but
with different timings coinciding with upwelling events: an initial phase, from the beginning of the experiment to day 9,
characterized by few species and low (or no) abundances; a second phase following the first upwelling characterized by moderate
abundances of Chromadorina, Chromadorella, Daptonema and Euchromadora sp. 3; a third phase following the second upwelling period (from day 26 onwards) in which Daptonema disappeared and the assemblage was characterized by moderate to high abundances of Euchromadora (species 1 and 2) and Chromadorella. Although shifts in nematode assemblage structure coincided with upwelling events no evidence was found for sediments being
the primary source of colonizers on the aluminium substrata, in contrast to our hypothesis. 相似文献
Wastewater is major source of contaminants originating from the production, usage, and disposal of plastic materials. Due to their poor biodegradability of these contaminants in municipal wastewater treatment plants, additional advanced oxidation processes such as electrochemical treatments have been developed to improve the standard biological treatment. Here we review the applications of electrochemical treatments of wastewater for the removal of the following plastic contaminants: bisphenol A, phthalic acid esters, and benzotriazoles. We present the effectiveness of treatment in terms of contaminant removal and mineralization; the identification of transformation products; toxicity assessment; and process energy requirements. In the present review, we have focused on the applications of electrochemical treatments of wastewater for the removal of three important groups of contaminants originating mainly from plastics: bisphenol A, phthalic acid esters, and benzotriazoles. The review focuses on the research of electrochemical treatments for these contaminants from the last five years. The papers are assessed from the point of i) effectiveness of treatment in terms of contaminant removal and mineralization; ii) identification of transformation products; iii) toxicity assessment; iv) processes’ energy requirements. Electrochemical treatments were confirmed to be a viable option for the removal of selected contaminants from wastewater.
In July 2012, a ship-board double-platform line-transect survey was conducted to assess harbour porpoise (Phocoena phocoena) abundance in the Kattegat, Belt Seas and the Western Baltic. A total of 826 km of track lines were surveyed between the 2nd and 21st of July 2012, and 169 observations were made by the primary observers, comprising a total of 230 porpoises. Fifty-seven observations were identified as duplicate sightings observed by both tracker and primary observers and were used to correct for availability and perception bias of the primary detections. Using Mark–Recapture Distance Sampling analysis, we produced a model using the half-normal key function, including sightability as the only covariate to estimate the density and abundance of harbour porpoise within the 51,511 km2 survey area. Estimated detection probability on the transect line, known as g(0), was at 0.571 (±0.074; CV = 0.130). Using a point independence model of the detection function, the abundance of harbour porpoises within the survey area was estimated at 40,475 animals (95 % CI 25,614–65,041, CV = 0.235) with an associated density of 0.786 animals km?2 (95 % CI 0.498–1.242, CV = 0.235) and an average group size of 1.488 animals. These results reflect densities obtained during the SCANS surveys in 1994 and 2005, indicating no significant population trend in the area. However, it should be noted that the survey area covers more than one population and that results are therefore not necessarily reflecting local population trends. Until proper population borders are obtained, the abundance estimate provides baseline data for future monitoring and is an important input to the assessment of the conservation status of harbour porpoises in the area. 相似文献
We compiled details of over 8000 assessments of protected area management effectiveness across the world and developed a method
for analyzing results across diverse assessment methodologies and indicators. Data was compiled and analyzed for over 4000
of these sites. Management of these protected areas varied from weak to effective, with about 40% showing major deficiencies.
About 14% of the surveyed areas showed significant deficiencies across many management effectiveness indicators and hence
lacked basic requirements to operate effectively. Strongest management factors recorded on average related to establishment
of protected areas (legal establishment, design, legislation and boundary marking) and to effectiveness of governance; while
the weakest aspects of management included community benefit programs, resourcing (funding reliability and adequacy, staff
numbers and facility and equipment maintenance) and management effectiveness evaluation. Estimations of management outcomes,
including both environmental values conservation and impact on communities, were positive. We conclude that in spite of inadequate
funding and management process, there are indications that protected areas are contributing to biodiversity conservation and
community well-being. 相似文献
The dynamic increase in the manufacture of rubber products, particularly those used in the automobile industry, is responsible for a vast amount of wastes, mostly in the form of used tyres, of which more than 17 million tonnes are produced globally each year. The widely differing chemical compositions and the cross-linked structures of rubber in tyres are the prime reason why they are highly resistant to biodegradation, photochemical decomposition, chemical reagents and high temperatures. The increasing numbers of used tyres therefore constitute a serious threat to the natural environment. The progress made in recent years in the management of polymer wastes has meant that used tyres are starting to be perceived as a potential source of valuable raw materials. The development of studies into their more efficient recovery and recycling, and the European Union's restrictive legal regulations regarding the management of used tyres, have led to solutions enabling this substantial stream of rubber wastes to be converted into energy or new polymer materials. In this article we present the relevant literature describing innovative organizational approaches in the management of used tyres in the European Union member countries and the possible uses of waste tyres as a source of raw materials or alternative fossil fuels. 相似文献
With the rising emphasis on biofuels as a potential solution to climate change, this paper asks whether certification schemes, developed to promote sustainable feedstock production, are able to deliver genuine sustainability benefits. The Round Table on Responsible Soy (RTRS) is a certification scheme that aims to promote responsible soy production through the development of principles and criteria. However, can and does this initiative address the negative impacts associated with the intensive production of soy? Taking the example of soy biodiesel produced in Argentina, this paper asks whether the social and environmental impacts of soybean production can be mitigated by the RTRS. It concludes that at present certification schemes are unlikely to be able to address either the institutional challenges associated with their implementation or the detrimental impacts of the additional demand generated by biofuels. 相似文献