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Registros recuperados: 55 | |
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Dive, D.; Persoone, G.. |
A critical examination of the utility of protozoan bioassays in marine as well as in freshwater ecotoxicology implies the answer to three basic questions: why, how and when. Arguments in favor of tests with Protozoa are: protozoans combine all biological mechanisms and functions in one single cell; the physiology and biochemistry of several species has been studied extensively; the generation time of Protozoa is very short in comparison to Metazoa; large numbers of organisms can be produced in a small volume; induction of cryptobiotic stages is possible with some species; Protozoa play a significant role in aquatic ecosystems; test methodologies with very sensitive criteria can be worked out. The two basic approaches for bioassay are <i>in... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ecotoxicology; Test organisms; Protozoa. |
Ano: 1984 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3264 |
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Michel, Pierre. |
Arsenic levels of in the marine environment are high in comparison with other contaminants. Over the past twenty years, a large number of arsenic organic compounds have been identified in the water, sediments and living species. This document constitutes a synthesis of current knowledge on arsenic sources, and contamination levels, on its biogeochemical cycle as well as its toxic effects on human and marine fauna. This paper highlights in particular the effects of phosynthesis on arsenic speciation and its distribution throughout the marine environment. Problems of toxicity in the case of certain phyto- and zooplankton species are identified. Bioaccumulation in seaweeds, molluscs and fishes is documented as well, with special attention to the species... |
Tipo: Text |
Palavras-chave: Ecotoxicology; Contamination; Biogeochemistry; Arsenic; Ecotoxicologie; Contamination; Biogéochimie; Arsenic. |
Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/1993/rapport-1448.pdf |
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Beiras, Ricardo; His, Edouard. |
The effects of mercury (Hg) concentrations ranging from 0 (control) to 1024 µg 1-1 upon embryogenesis, survival, growth and metamorphosis of Crassostrea gigas (Thunberg) oyster larvae were investigated. Embryogenesis was abnormal in 50 % of the individuals at 11 µg 1-1 . The 48 h LD50 for D·shaped, umbonate and pediveliger larvae were 33, 115 and 200 µg 1-1 respectively. The increase in LD50 was partially explained by the larval weight increase, although weight-specific tolerance to Hg was higher in smaller larvae. Growth, the most sensitive physiological process studied, was significantly retarded at 4 µg 1-1. The metamorphosis rate was significantly reduced when competent pediveligers were exposed to 64 µg 1-1 for 48 h prior to the addition of the... |
Tipo: Text |
Palavras-chave: Mercury; Oyster; Larvae; Embryo; Bioassay; Ecotoxicology; Crassostrea gigas. |
Ano: 1994 |
URL: http://archimer.ifremer.fr/doc/00037/14867/12191.pdf |
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Beiras, R; His, Edouard. |
The effects of Hg concentrations ranging from 0 (control) to 1024 mu g l(-1) upon embryogenesis, survival and growth of Mytilus galloprovincialis mussel larvae were investigated. Embryogenesis was abnormal in 50% of the individuals at 10 mu g l(-1). The 48 h LC(50) for D-shaped, early umbonate, late umbonate and eyed larvae were 51, 164, 322 and 383 pg l(-1) respectively. The LC(50) was an allometric function of ash-free dry weight with exponent b = 0.60. Larval growth was significantly reduced after 6 d exposure to 4 mu g Hg l(-1) and after 10 d exposure to 2 mu g l(-1). No significant differences in lethal or sublethal sensitivity to Hg were found between M. galloprovincialis and previously studied Crassostrea gigas embryos and larvae. The implications... |
Tipo: Text |
Palavras-chave: Mercury; Mytilus; Mussel; Larva; Growth; Embryo; Bioassay; Ecotoxicology. |
Ano: 1995 |
URL: http://archimer.ifremer.fr/doc/00258/36946/35665.pdf |
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Beiras, Ricardo; His, Edouard. |
The effects of Hg concentrations ranging from 0 (control) to 1024 µg 1-1 upon embryogenesis, survival and growth of Mytilus galloprovincialis mussel larvae were investigated . Embryogenesis was abnormal in 50 % of the individuals at 10µg 1-1. The 48 h LC50 for D-shaped, early umbonate, late umbonate and eyed larvae were 51, 164, 322 and 383 µg 1- 1 respectively. The LC50 was an allometric function of ash-free dry weight with exponent b = 0.60. Larval growth was significantly reduced alter 6 d exposure to 4 µg Hg 1-1 and alter 10 d exposure to 2 µg 1-1. No significant differences in lethal or sublethal sensitivity to Hg were found between M. galloprovincialis and previously studied Crassostrea gigas embryos and larvae. The implications of these findings for... |
Tipo: Text |
Palavras-chave: Mercury; Mytilus galloprovincialis; Mussel; Larvae; Growth; Embryonic development; Bioassay; Ecotoxicology. |
Ano: 1995 |
URL: http://archimer.ifremer.fr/doc/00037/14868/12192.pdf |
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KARASOV,WILLIAM H.; MEYER,MICHAEL W.. |
Environmental contaminants are ubiquitous and so are often key suspects in cases of lagging wildlife populations. How do we test hypotheses about cause-effect linkages between contaminants and wildlife health? We present three case studies in which different approaches were used to test hypotheses about effects of contaminants on wildlife. The cases involve the possible impacts of (1) polychlorinated biphenyl on Lake Superior bald eagles (Haliaeetus leucocephalus); (2) dioxin on osprey (Pandion halieatus); and (3) methyl mercury on common loons (Gavia immer). The different approaches were dictated by legal, logistic, and financial limitations, but the relative strengths of experimental and mechanistic approaches over correlative approaches is underscored.... |
Tipo: Journal article |
Palavras-chave: Applied physiological ecology; Ecotoxicology; Birds; Chemical contaminants. |
Ano: 2000 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2000000300009 |
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Laubier, Lucien; Le Moigne, Morgan; Flammarion, Patrick; Thybaud, Eric; Cossa, Daniel. |
On December 11, 1999, Erika, an oil tanker flying the Maltese flag and loaded with 31 000 t of heavy fuel oil, was making its way from Dunkirk to Livorno when it encountered difficult weather conditions Southwest of the Brittany coast gale force winds 8 to 9 and 6 mwaves). On the morning of 12th December, the captain broadcast an SOS; his vessel was breaking in two, approximately 30 nautical miles to south of Penmarc'h Point (Fig. 1; Finistère, France). The fore section of the vessel sank during the night of the 12-13 December and the aft section was taken in tow on the morning December 13, but subsequently sank in the early afternoon. Both parts lay in 120 m of water and were located 10 km apart. Approximately, 19 000 t of heavy fuel oil were spilled into... |
Tipo: Text |
Palavras-chave: Atlantique; France; Monitoring programme; Hydrocarbon; Erika; Marine pollution; Ecotoxicology; Ecology. |
Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-1390.pdf |
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Registros recuperados: 55 | |
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