摘要:

AbstractA bloom ofCerataulina pelagicadominated the sea area off the north‐east coast of New Zealand for three months in the summer of 1982–83, and has been related to unusually calm conditions associated with an unusually low Southern Oscillation Index. Deaths of benthic shellfish during the bloom were attributed to anoxia induced by the bacterial decay of the diatom cells. Death of bony fish caught on long‐lines was attributed to anoxia and the clogging of the gills with mucilage produced by the di

ISSN:0020-9309    

DOI:10.1002/iroh.19850700602

出版商:Akademie Verlag, Berlin    

年代:1985

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19850700604

出版商:Akademie Verlag, Berlin    

年代:1985

数据来源: WILEY

摘要:

AbstractProductive, natural oyster reefs within the James River estuary, were quantitatively sampled for associated macrofauna for a year. The 192 samples yielded 142 taxa. Mean faunal density on these reefs ranged from 5,757 to 57,857 m−2. Over 770/0 of the individuals collected belonged to 11 taxa. The number of species and informational diversity (H') decreased up the estuarine gradient.The quality of available shell surface was deemed important in determining density. The spatial heterogeneity provided by the shell surface allowed development of a densely populated, diverse faunal assemblage which differs from soft‐bottom assemblages principally in quantitative aspects. The assemblage is not spatially or temporally homogeneous and undergoes significant changes in community structure both seasonally and along the estuarine gradi

ISSN:0020-9309    

DOI:10.1002/iroh.19850700605

出版商:Akademie Verlag, Berlin    

年代:1985

数据来源: WILEY

摘要:

AbstractMicrobial investigations on heterotrophic bacteria (MPN counts, adenylates charge, growth rate and enzymatic activities) and hydrocarbon utilizing microorganisms (MPN counts) were carried out during three years in the salt marshes of Ile Grande. The aim was to follow their recovery after oil pollution.Oil degradation is related to bacterial activity (depending on site, depth in the soil, redox level and hydrocarbon concentrations). The results for the three years show a significant enhancement of the microflora during the first year (corresponding to removal of n. alkanes) followed by a decrease in bacterial activity which persisted for over two years. The activity of the heterotrophic bacterial population is deeply disturbed compared with unoiled sites, and these shifts remain detectable three years after oiling. This study does not modify our previous estimation regarding the recovery of the salt marshes.

ISSN:0020-9309    

DOI:10.1002/iroh.19850700606

出版商:Akademie Verlag, Berlin    

年代:1985

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19850700607

出版商:Akademie Verlag, Berlin    

年代:1985

数据来源: WILEY

摘要:

AbstractThe phytoplankton biomass expressed as total cell volume is often of doubtful value due to cell size and volume variations in the organisms present. Cell volume calculations for 95 phytoplankton species and volume‐frequency diagrams for 25 dominant species were analyzed for the Adriatic Sea. Recommendations for more precise work dealing with phytoplankton cell volume and biomass are given. Temporal variations in the average microplankton cell volume are presented and discusse

ISSN:0020-9309    

DOI:10.1002/iroh.19850700608

出版商:Akademie Verlag, Berlin    

年代:1985

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19850700609

出版商:Akademie Verlag, Berlin    

年代:1985

数据来源: WILEY

摘要:

AbstractTwenty four reservoirs in Central India were investigated for their physical, chemical and biological features. These reservoirs differed significantly in their size, physical features, chemical composition and vegetation. Three medium and major reservoirs recorded comparatively low electrical conductivity. All the eighteen minor reservoirs showed high conductivity and low transparency since they were all situated in densely populated urban areas polluted by human faeces and domestic sewage. The most abundant ions in water are calcium, carbonate and chloride. The phytoplankton was found to be dominated by Cyanophyceae. Rotifers dominated among zooplankton. All the minor reservoirs are highly eutrophicated. Among the major reservoirs Tawa Reservoir is oligotrophic while others are mesotrophic to eutrophic in nature.

ISSN:0020-9309    

DOI:10.1002/iroh.19850700610

出版商:Akademie Verlag, Berlin    

年代:1985

数据来源: WILEY

摘要:

AbstractObservations in respect of Rihand Reservoir based on monsoon inflow, reservoir level, evaporation loss, air and water temperature, rainfall and wind velocity have been discussed in relation to the physical and chemical parameters of the water body. A weak thermocline has been observed, and the water showed a biogenic chemical stratification during the warmer months. Rihand is a monomictic tropical lake with a moderate nutrient supply, but is not very productive from the limnological point of view. The nutrient content of this lake declined from 1972 to 1974, but improved in 1975 and 1976 with the increase in rain and inflow of water. The productivity of the reservoir depends greatly on the nutrient level of the inflowing water from the catchment area, so that the monsoon inflow largely influences the water quality of the reservoir.

ISSN:0020-9309    

DOI:10.1002/iroh.19850700611

出版商:Akademie Verlag, Berlin    

年代:1985

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19850700612

出版商:Akademie Verlag, Berlin    

年代:1985

数据来源: WILEY