摘要:

AbstractThis paper contains the results obtained in the investigations of morphology, ultrastructure and vertical distribution of microorganisms in a stratified lake, Lesnaya Lamba, Karelia. The culture ofOchrobium tectum(PERF.) was produced for the first time, and the bacterial nature of this organism was shown by investigating its ultrathin structure. The presence of gaseous vacuoles was also revealed, which explains the migrational ability of ferritized cells. Several new microorganisms were detected, including the filamentous photosynthetic green bacteriumChloronema giganteum(nov. gen. nov. sp.), a consortium of a new symbiotic form of green bacteria namedChloroplana vacuolata, formerly unknown tiny purple bacteria and blue‐green algaeGloeocapsa, oxidizing iron. It was revealed that more than half of the bacterio‐plankton in the bottom layer possess gaseous vacuoles; they are represented by various morphological forms. The vertical distribution of iron bacteria —Siderocapsa (Arthrobacter), Ochrobium, Siderococcusand other species is regulated according to ecological niches by the concentration of oxygen and iron, and, in phototrophs, by the amount of light and the presence of a certain type of bacteriochlorophyll. All in all, the distribution of nine species of phototrophic bacteria in the lake is desc

ISSN:0020-9309    

DOI:10.1002/iroh.19760610102

出版商:Akademie Verlag, Berlin    

年代:1976

数据来源: WILEY

摘要:

AbstractIn a chemical investigation of the sediments of a small meromictic lake in southwestern Ontario, Canada, the hypolimnion had evidently become increasingly reductive over most of the postglacial as the lake gradually filled in. The ratio of phosphorus to organic matter tended to fall, suggesting that an increasing proportion of precipitated phosphorus had become mobile and re‐available to the lake's ecosystem. Productivity, as inferred from fossil pigment analysis, tended to increase over the postglacial, and there is no evidence for a prolonged period of trophic equilibrium. Maximum production rates were correlated with efficient phosphorus diagenesis. The lake evidently became meromictic around 900 BP (before present) and this was associated with a sulphide producing monimolimnion and decreased productivity. Cultural practices in the watershed around 140 BP increased inorganic sedimentation and further reduced productivit

ISSN:0020-9309    

DOI:10.1002/iroh.19760610103

出版商:Akademie Verlag, Berlin    

年代:1976

数据来源: WILEY

摘要:

AbstractA study using the submerged test panel method was conducted at the Oyster Creek Nuclear Generating Station near Barnegat Bay, New Jersey to investigate effects of the heated effluent on epibenthic communities. Test panels were placed in the intake and discharge canals and collected using SCUBA at 28, 84, 168 and 335‐day intervals between October 1970 and October 1971. Exposed panels were replaced by clean panels upon collection.Faunal resemblance, both between stations during a sampling date and within stations from one sampling date to the next, was low. Numbers of species were higher at the discharge station than at the intake station from late fall to early summer and lower from midsummer to early fall. Overall differences in diversity at the two stations could not be detected. The optimum temperature for growth ofBalanussp. was approached more closely during winter in the discharge canal than in the intake canal where growth was retarded by cold water.Balanus eburneusappeared to have an extended breeding season. Because of dilution of the discharged water with cooler intake water through a plant bypass system during the summer, the effluent was not seriously harmful to amphipod reproduction. Season abundances of numerous invertebrates at both stations are reported and possible power plant effects are discusse

ISSN:0020-9309    

DOI:10.1002/iroh.19760610104

出版商:Akademie Verlag, Berlin    

年代:1976

数据来源: WILEY

摘要:

AbstractThe physico‐chemical environment was studied from June 1971 to May 1973 at five stations in Long Pond, St. John's, Newfoundland. This pond receives both rural and urban runoff and is characterized by a high flushing rate. Of the parameters studied, concentrations of total suspended matter, biochemical oxygen demand (BOD), total CO2, and free CO2were significantly greater in a small pool prior to the main body of the pond near the entry of Learys Brook. Current speed is noticeably reduced at this point. No significant differences were found between stations with respect to pH, dissolved O2, total dissolved solids (TDS), total hardness, Ca hardness, Mg hardness, alkalinity, ammonium‐N, nitrite‐N, nitrate‐N, orthophosphate and polyphosphate. Water quality in Long Pond is compared with unpolluted lakes and streams in the area; nutrient levels are indicative of eutrophic con

ISSN:0020-9309    

DOI:10.1002/iroh.19760610105

出版商:Akademie Verlag, Berlin    

年代:1976

数据来源: WILEY

摘要:

AbstractThe meiofauna of the Saaler Bodden was investigated in the period from September 1969 to April 1970. The Saaler Bodden is that part of a brackish water area which is situated farthest from the Baltic Sea. In the southern part we usually find fresh water; in the northern part, the salinity rises to a maximum of 5 to 6‰. The authors give a short review of the hydrographical and biological peculiarities of the Saaler Bodden followed by remarks as to the qualitative and quantitative distribution of the meiofauna. Abundance and biomass are determined for Nematoda, Oligochaeta, Ostracoda, Copepoda, Harpacticoidea, Halacarida and Chironomid larvae. Oligochaeta and Ostracoda are dealt with in detail. The ecological requirements of the different species are discussed in this connection and their role in the balance of matter of this water body is pointed ou

ISSN:0020-9309    

DOI:10.1002/iroh.19760610106

出版商:Akademie Verlag, Berlin    

年代:1976

数据来源: WILEY

摘要:

AbstractSolenofilomorphids are of world‐wide distribution and live in association with the sulfide system, the anoxic and micro‐oxic layers of marine sediments. The 58 species of turbellarians on an intertidal sand flat in North Carolina, U.S.A., formed three species assemblages. The solenofilomorphids are a major part of a sulfide system assemblage which is centered in the mid‐tide region and which is intermediate in density and diversity between the two separate species assemblages in the surface layers of the upper and lower tide regions. Oxygen avoidance does not explain restriction of species to the sulfide system, and food preferences for and behavioral responses to specific bacterial species are suggested as proximal causes for observed distribu

ISSN:0020-9309    

DOI:10.1002/iroh.19760610107

出版商:Akademie Verlag, Berlin    

年代:1976

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19760610109

出版商:Akademie Verlag, Berlin    

年代:1976

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19760610110

出版商:Akademie Verlag, Berlin    

年代:1976

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19760610111

出版商:Akademie Verlag, Berlin    

年代:1976

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19760610113

出版商:Akademie Verlag, Berlin    

年代:1976

数据来源: WILEY