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31.
Between December 1993 and February 1997, 302 electronic data storage tags (DSTs), programmed to record depth at 10-min intervals and temperature daily, were attached to mature female plaice, Pleuronectes platessa, and released in the southern North Sea. Fifty tags were returned, 38 of which functioned fully and recorded 2,955 days of data. Twenty-seven tags recorded data over the full period at liberty, and 34 geographical ground tracks were reconstructed. Reconstruction was performed using a two-dimensional tidal stream simulation model that translated vertical movement of fish, recorded by DSTs, into horizontal movement assuming an initial down-tide swimming speed of 0.6 body lengths s–1. Geographical accuracy of reconstructed tracks was assessed based on closeness of fit between (1) reconstruction endpoint and reported recapture position; (2) reconstructed locations and corresponding locations based on tidal data recorded by DSTs using the tidal location method (TLM; location of areas with similar tidal range and time of high water); and (3) DST temperature records and corresponding averaged sea surface temperature data records for corresponding locations. The results demonstrate that the assumptions of the tidal stream simulation model were sufficient to reconstruct geographically accurate representations of the migrations of individual plaice, which have in turn provided new information on the extent, duration, and directionality of movement. Our study demonstrates how DSTs can provide fishery-independent data with direct management applications in behaviourally driven, individual-based predictive models of fish migration.Communicated by J.P. Thorpe, Port Erin 相似文献
32.
Toxicity of methyl tert-butyl ether to marine organisms: ambient water quality criteria calculation 总被引:3,自引:0,他引:3
In response to increasing concerns over the detection of methyl tert-butyl ether (MTBE) in groundwater and surface water and its potential effects in aquatic ecosystems, industry and the United States Environmental Protection Agency (USEPA) began to collaborate in 1997 to develop aquatic toxicity databases sufficient to derive ambient water quality criteria for MTBE consistent with USEPA requirements. Acute toxicity data for seven marine species, chronic toxicity data for an invertebrate, and plant toxicity data were developed to complete the saltwater database. The species tested were Cyprinodon variegatus, Gasterosteus aculeatus, Callinectes sapidus, Mytilus galloprovincialis, Palaemonetes pugio, Rhepoxynius abronius, Americamysis bahia, and Skeletonema costatum. The toxicity tests were conducted in accordance with USEPA and American Society for Testing and Materials testing procedures and Good Laboratory Practice guidelines. Data developed from this study were consistent with existing data and showed that MTBE has low acute and chronic toxicity to the marine species tested. Based upon measured MTBE concentrations, acute effects were found to range from 166 mg MTBE/l for the grass shrimp to 1950 mg MTBE/l for marine mussel. The no-observed effect concentration for the reproduction and growth of mysids was 26 mg MTBE/l during the life cycle test. The toxicity of MTBE to saltwater organisms is comparable to its toxicity to the freshwater species tested. Reported MTBE concentrations in coastal waters are several orders of magnitude lower than concentrations observed to cause effects in marine organisms. 相似文献
33.
Reproduction study of toxaphene in the rat 总被引:1,自引:0,他引:1
I Chu V Secours D C Villeneuve V E Valli A Nakamura D Colin D J Clegg E P Arnold 《Journal of environmental science and health. Part. B》1988,23(2):101-126
The purpose of the present study was to investigate in rats the reproductive effects of toxaphene, an insecticidal mixture which has been identified as a pollutant in the Great Lakes ecosystem. Groups of 30 female and 15 male weanling rats were given toxaphene in the diets at 0, 4.0, 20, 100 or 500 ppm in a 1 generation 2 litter reproduction study. Toxaphene treatment at the levels studied had no effects on the litter size, pup weight, fertility, or gestation and survival indices. Toxic effects in the parental rats included depressed weight gain, elevated serum cholesterol, and increased liver and kidney weight and hepatic microsomal enzyme activities. Most of these effects were associated only with 500 ppm toxaphene treatment. Treatment-related histological changes in the liver, thyroid and kidney of adult rats were observed at levels as low as 20 ppm. Based on the data presented, the no observable adverse effect dose of toxaphene was considered to be 4.0 ppm in the diet (0.29-0.38 mg/kg b.w./day depending on the amount of dietary intake). 相似文献
34.
Vinzenz Brendler Annett Vahle Thuro Arnold Gert Bernhard Thomas Fanghnel 《Journal of contaminant hydrology》2003,61(1-4):281
This paper presents a digitized version of a thermodynamic sorption database, implemented as a relational database with MS Access. It is mineral-specific and can therefore be used for additive models of complex solid phases such as rocks or soils. An integrated user interface helps users to access selected mineral and sorption data, to extract internally consistent data sets for sorption modeling, and to export them in formats suitable for other modeling software. Data records comprise mineral properties, specific surface area values, surface binding sites' characteristics, sorption ligand information, and surface complexation reactions. An extensive bibliography is included, providing links not only to the above listed data, but also to background information concerning surface complexation model theories, evidence for surface species, and sorption experimental techniques. 相似文献
35.
Environmental photodegradation of mefenamic acid 总被引:1,自引:0,他引:1
Pharmaceuticals and personal care products are an emerging class of environmental pollutants. Photolysis is expected to be a major loss process for many of these compounds in surface waters, including the common non-steroidal anti-inflammatory drug mefenamic acid. The direct photolysis solar quantum yield of mefenamic acid was observed to be 1.5+/-0.3x10(-4). Significant photosensitization was observed in solutions of Suwanee River fulvic acid and Mississippi River water, as well as for the model photosensitization compounds 3'-methoxyacetophenone, 2-acetonaphthone and perinaphthenone. Quenching, sparging and light-filtering experiments suggested a direct reaction of mefenamic acid with excited triplet-state dissolved organic matter as the major photosensitization process. The persistence of the model photosensitizer suggests that the photosensitization by perinaphthenone occurs either by triplet-energy transfer or an electron transfer followed by rapid regeneration of the sensitizer. Due to its low quantum yield, the loss of mefenamic acid in sunlit natural waters is expected to depend on both direct and indirect photodegradation processes. 相似文献
36.
The Science of Nature - 相似文献
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Arnold B. Bakker Wilmar B. Schaufeli Herman J. Sixma Willem Bosveld Dirk Van Dierendonck 《组织行为杂志》2000,21(4):425-441
This study among a sample of 207 general practitioners (GPs) uses a five‐year longitudinal design to test a process model of burnout. On the basis of social exchange and equity theory, it is hypothesized and found that demanding patient contacts produce a lack of reciprocity in the GP–patient relationship, which, in turn, depletes GPs' emotional resources and initiates the burnout syndrome. More specifically, structural equation analyses confirmed that—both at T1 and T2—lack of reciprocity mediates the impact of patient demands on emotional exhaustion. Emotional exhaustion, in turn, evokes negative attitudes toward patients (depersonalization), and toward oneself in relation to the job (reduced personal accomplishment). Moreover, this process model of burnout was confirmed at T2, even after controlling for T1‐scores on each of the model components. Finally, T1 depersonalization predicted the intensity and frequency of T2 patient demands, after controlling for T1 patient demands. This major finding suggests that GPs who attempt to gain emotional distance from their patients as a way of coping with their exhaustion, evoke demanding and threatening patient behaviors themselves. The theoretical and practical implications of these findings are discussed. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献