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941.
Bestimmung von Nitrodiphenylaminen und verwandten Verbindungen im Sickerwasser einer Rüstungsaltlast
Goal, Scope and Background
Nitrodiphenylamines can be found at abandoned military sites where the explosive 2,2′,4,4′,6,6′-hexanitrodiphenylamine (hexyl) or diphenylamine as a stabilizer of smokeless powder was handled. Aim of the present study is the development of HPLC methods for the analysis of contaminants which can be expected in particular under aerobic conditions at premises which are contaminated by nitrodiphenyl-amines and related compounds.Methods
A list of 13 compounds which can be expected at these explosives factories was deduced from literature studies. HPLC methods were developed for the analytes. Water samples from the unsaturated zone of a former hexyl-producing factory were collected by suction cups and the material was analysed according to these procedures to demonstrate the practicability of the new methods and to verify the existence of the postulated compounds in the environment of the former nitration plant.Results and Conclusion
The new HPLC methods are suitable for the exploration of sites contaminated by nitrodiphenylamines. Beside some hexyl its intermediates 1-chloro-2,4-dinitrobenzene, 2,4-dinitrodiphenylamine und 2,2′,4,4′-tetranitrodiphenylamine were identified in the leachate water.Recommendation and Perspective
It is advisable to include at least these 4 compounds in the examination of former hexyl-producing plants. Several unknown peaks were observed in the HPLC-chromatogram. It is recommendable to perform further investigations of the unidentified compounds to compile a final list of analytes for military sites polluted by nitrodiphenylamines. 相似文献942.
Black spots and female association preferences in a sexual/asexual mating complex (Poecilia, Poeciliidae, Teleostei) 总被引:1,自引:0,他引:1
Michael Tobler Martin Plath Heike Burmeister Ingo Schlupp 《Behavioral ecology and sociobiology》2006,60(2):159-165
We investigated whether female association preferences for males are influenced by black spot disease (BSD), a parasite induced change of the host phenotype. We compared three different species of fish: a gynogenetic hybrid species, Poecilia formosa (amazon molly) and two sexual species (Poecilia latipinna and Poecilia mexicana), which were involved in the natural hybridisation leading to the amazon molly. Contrary to their sexual relatives, asexual amazon mollies significantly avoided images of males infected with black spot disease. We propose that amazon molly females have direct fitness benefits from choosing healthy males. The adaptive significance of the preference for BSD-uninfected males in the asexual amazon molly is yet unclear but may involve avoidance of predation or parasite infection as well as increased sperm availability. 相似文献
943.
Aim and Scope
This study was aimed at evaluating environmental effects of tar-oil impregnated (tanalized) tree stakes using simple and efficient biotests to obtain results of its ecological impacts during the tar-oil breakdown in the stake.Results
- Soil respiration was measured in-situ as an indication of soil microbial activity in two field trials. Soil respiration was measured in a 20 year-old apple orchard at various distances from the tar-oil impregnated tree stakes and also on soil mixed with chippings from pine stakes with tar-oil impregnation of different ages.
- Cress germination tests were employed to evaluate tar-oil phytotoxicity in a field and laboratory trial. Cress was seeded close to tree stakes in the same 20 year-old apple orchard and germination rates related to tar oil-impregnation. Cress was also seeded in trays in sand mixed with pine chippings from stakes with tar-oil impregnation of different ages.
- The portion of the carcinogenic benzoapyrene (BaP) ranged between 0.0015% in freshly tar-oil impregnated to 0.4% in tar-oil impregnated 20-year old trees stakes, i.e. irrespective of the overall PAK concentration and its degradation.
- Kinetic analysis using DIXON plots showed a 50% breakdown of overall PAHs after ca. 2.7 years, i.e. km or Ki values of less than 3 years.
Conclusion
Germination tests of cress and endogenous seeds as well as soil respiration proved sensible indicators of the phytotoxicity and ecotoxicity of tar-oil impregnated tree stakes in fruit orchards. Soil respiration proved particularly sensitive to tar-oil ageing. Its combination with kinetic inhibition models resulted in parameters suitable for the interpretation of results. 相似文献944.
Nucleotide variation in cytochrome c oxidase subunit I (COI) was used to examine population structure in three invasive bryozoans: Bugula neritina (Linnaeus, 1758), Watersipora subtorquata (d’Orbigny, 1852), and W. arcuata (Banta, 1969). These species are found on ship hulls and have a short (≤2 days) larval phase. Samples were collected from 1998–2001 at multiple sites in Australia, and in Hong Kong, New Zealand, Hawaii, California, Curaçao, and England. B. neritina is known to include three cryptic species, including species Type S (Davidson and Haygood in Biol Bull 196:273–280, 1999) which occurs on the east and west coasts of the USA. One haplotype recorded previously in the USA, S1, was found to be widespread, occurring throughout Australia and in Hong Kong, Curaçao, Hawaii, and England. W. subtorquata, a Caribbean–Atlantic species which has invaded southern Australia, New Zealand, and California, had low nucleotide diversity in these areas (π=0.0016±0.0014), consisting of three haplotypes connected by one or two nucleotide mutations. W. arcuata, an Eastern-Pacific native, had comparatively high diversity (π=0.0221±0.0115) in introduced populations from Australia and Hawaii. In each species, identical haplotypes were identified on separate coastlines providing evidence of widespread, rather than genetically independent, introductions. The major contrast in nucleotide diversity suggests that different propagule-source models explain introductions. 相似文献
945.
Aušrinė Armaitienė Vadim L. Boldyrev Ramūnas Povilanskas Julius Taminskas 《Journal of Coastal Conservation》2007,11(1):13-22
The varied and very dynamic landscape with a high biological diversity is a distinctive feature of the Curonian spit at the
regional scale. Throughout the 20th century the main morphodynamic trend in the littoral of the Curonian spit was shoreline
grading on the lagoon side, whereas on the marine side the increasing erosion at the foot of the spit, and increasing accretion
at the head of the spit prevailed. The results of a discriminant analysis (Wilkes’ λ = 0.001626 and F = 29.267 when p < 0.001) show that sites with prevailing erosion, accretion and sediment input from the drifting dunes form regular inter-related
spatial structures in the littoral with distinctive resulting discontinuities of the sediment drift along the lagoon coast.
Dune littoral cells are characterized by Aeolian sediment input and distribution ‘down-drift’, (usually northwards) from the
source. The most likely changes in the current development trends of the lagoon shore zone of the Curonian spit are related
to expected climate changes and further slowing down of the dune drift. The probability of storms and ice-drift events, and
their impact on coasts is expected to increase as a result of climate change. The dune advance will gradually slow down, and
with it, the sand input to the coastal zone will decline. In this paper, we define integrated shoreline management as a system
of long-term shoreline management measures, which is based on a littoral cell approach and aimed at harmonizing human activity
in the coastal zone with the natural development of the shoreline. We propose an integrated management program for the lagoon
shoreline of the Curonian spit, which is site-specific for each littoral cell as a coastal management unit. Drifting dunes
and seaside beaches are the natural amenities, which are best known and best appreciated on the Curonian spit by 49% of the
respondents representing the total Lithuanian population. A responsible tourism development should be considered as the key
means for proper appreciation of the drifting dunes and natural coasts by society, which means to acknowledge and cherish
the aesthetic and conservation values of dune and coastal landscapes of the Curonian spit as a World Heritage Site. There
are at least two pre-conditions for this: (1) to provide visitors with sufficient information about diverse values and functions
of the Curonian dunes and coasts within a broader regional and global heritage conservation context; (2) to enable tourists
to enjoy the most impressive dune and coastal landscapes at close range. In this paper we propose to encourage active dune
tourism, to reintroduce grazing into the Curonian dune areas, to restore and to preserve the most impressive landscapes of
the highest white drifting dunes by bringing the blown out sand from the leeward foot of the dunes back to the crest artificially. 相似文献
946.
Spencer E. Fire Deborah Fauquier Leanne J. Flewelling Michael Henry Jerome Naar Richard Pierce Randall S. Wells 《Marine Biology》2007,152(4):827-834
Bottlenose dolphins (Tursiops truncatus) face a variety of threats, including risk of exposure to brevetoxins produced by blooms of the harmful alga Karenia brevis. This study investigated brevetoxin exposure in a population of dolphins inhabiting Sarasota Bay, Florida, USA (27°N, 82°W),
utilizing tissues from dolphins recovered between 1994 and 2003. Brevetoxin levels detected by ELISA in tissues, gastric samples
and excreta from dolphin carcasses (n = 19) associated with K. brevis blooms were compared with with levels in carcasses (n = 16) associated with background K. brevis conditions. In the K. brevis-exposed set, 84% of dolphin carcasses recovered during K. brevis blooms had detectable brevetoxin levels, with values ranging between 7 and 2,896 ng PbTx-3 eq g−1. Over 50% of dolphin carcasses recovered during non-bloom conditions also tested positive by ELISA for brevetoxins, with
concentrations ranging from 6 to 44 ng PbTx-3 eq g−1. Control samples from the east coast of Florida were negative by the ELISA. Results from this study establish baseline brevetoxin
body burdens in a dolphin population frequently exposed to K. brevis blooms, and data indicate that dolphin carcasses not associated with large-scale mortality events can contain levels of brevetoxins
comparable to carcasses stranding during such events. 相似文献
947.
948.
Relatively low concentrations of fluorine in drinking water ( 1 mg F/l) have been shown to significantly reduce the degree of dental caries in children and fluorine would also appear to have a beneficial effect on bone formation in both humans and farm animals. However, it is apparent that elevated levels of fluorine in the diet have sometimes resulted in problems of increased dental caries and of the development of bone deformities. Much of the fluorine in rocks and soils occurs in apatite and hydroxysilicate minerals, fluorite being the only relatively common rock forming mineral containing fluorine as an essential constituent.Little systematic data are available on fluorine concentrations in soils, plants and natural waters in the UK. General background soil concentrations lie in the range 200 – 400 mg F/kg. For waters the average fluorine content is low, <0.1 mg F/l.In the British Isles there are several areas where there are enhanced levels of fluorine. In the northern Pennines, Derbyshire, northeast Wales and Cornwall, fluorite occurs as a significant component of mineralisation and much fluorine has been added to the environment from mining waste dumps. Soils in northeast Wales contain up to 3,650 mg F/kg and in the northern Pennines up to 20,000 mg F/kg. Waters contain up to 2.3 mg F/l. In southwest England, the granites are generally fluorine-rich with the fluorite granites of the St Austell pluton containing as much as 1 percent fluorine. These rocks are frequently kaolinised and intensively worked as a source of china clay. Soils in the vicinity of the waste tips contain up to 3,300 mg F/kg and grasses up to 2,950 mg F/kg. Surface waters in the St Austell area contain up to 1.25 mg F/l.Atmospheric fluorine pollution around brickworks in the Peterborough and Bedford areas has resulted in fluorosis in farm animals. Other sources of atmospheric fluorine pollution are aluminium smelters, steelworks and fossil fuel burning. 相似文献
949.
The distribution of molluscan assemblages and their postmortem fate on coral reefs in the Gulf of Aqaba (northern Red Sea) 总被引:1,自引:0,他引:1
Molluscan assemblages were studied on fringing reefs (reef flats, Millepora-fringing reefs, fringing reefs with massive corals) and fore-reef hard substrata (coral patches, coral carpets and small
patch reefs) in the Gulf of Aqaba at water depths ranging from the intertidal to 26 m. A total of 1,665 molluscan individuals
from 51 taxa was counted on 44 transects, which covered 220 m2 at eight diving sites. The most important molluscs in the assemblage
were the parasitic gastropod Coralliophila neritoidea, the encrusting gastropod Dendropoma maxima and the coral-associated bivalve Pedum spondyloideum. The dead assemblage, in contrast, was dominated by encrusting bivalves (Ostreoidea, Chamoidea, Spondylidae) and the coral-predating
gastropod Drupella cornus. Distinct molluscan assemblages inhabit each of the three fringing reef-habitats and most of the important depth-related
community changes occurred within the uppermost 5 m. In contrast, the three deeper fore-reef habitats are characterized by
a more uniform molluscan composition. Molluscan assemblages were more dependent on substrata and their coral associations
than on water depth. Comparisons with other published studies indicate that reefoidal hard substrata in the northern Red Sea
are largely characterized by similar species-abundance patterns. The minor differences to other Red Sea studies probably reflect
the northern, isolated position of the Gulf of Aqaba, the lack of certain molluscan habitats, and the differential impact
of anthropogenic influences. Strong differences between living and dead assemblages in Aqaba are similar to those observed
in other regions and are due to distinct biases in the dead assemblage. Molluscs closely associated with living corals (mostly
bivalves and Dendropoma) can easily be overgrown after death and are thus undetectable in visual censuses. Some gastropod taxa are preferentially
transported into surrounding soft-substrata postmortem or redistributed by hermit crabs. Such complex relationships between
ecology and taphonomy are crucial in evaluating the quality of the molluscan fossil record in coral reef environments. The
comparison of our results with literature data documents an increase in coral predators during the last two decades in the
northern Red Sea. Due to the greater mollusc biodiversity in the shallower Aqaba reef habitats, damage to this coral reef
zone would have the greatest impact on the overall mollusc community. 相似文献
950.
Michael R. Heithaus Aaron J. Wirsing Lawrence M. Dill Linda I. Heithaus 《Marine Biology》2007,151(4):1455-1461
Tiger sharks are important predators in the seagrass ecosystem of Shark Bay, Australia. Although sharks appear to return to
a long-term study site within the Eastern Gulf periodically, the extent of their long-term movements is not known. Five sharks
fitted with satellite transmitters showed variable movement patterns. Three sharks remained within the Shark Bay region and
another made a 500 km round-trip excursion to oceanic waters northwest of the bay. These four sharks showed relatively low
displacement rates relative to sharks tracked over shorter time periods, suggesting that sharks move through large home ranges
that include Shark Bay. Although no reliable position fixes were obtained for the fifth shark, we were able to use the timing
of satellite uplinks and the position of the satellite to determine that it had moved at least 8,000 km to the coastal waters
of southeast Africa in 99 days—the longest recorded movement by a tiger shark. This movement and previously documented trans-Atlantic
movements suggest that tiger shark populations may mix across ocean basins and that tiger sharks are subject to anthropogenic
effects at great distances from protected waters. Finally, our method for using single satellite uplinks may be useful in
estimating movements for wide-ranging species that rarely provide high quality location estimates. 相似文献