摘要:

AbstractBenthic size structures were compared between sublittoral, upper‐slope and deep‐sea areas of the Western Pacific using the mesh‐size fractionated distribution of organisms. The average size of the individuals became smaller with increasing water depth, suggesting that the dwarfism is a more common phenomenon than the gigantism in the deep sea. Nonetheless, the mesh size of 0.037 mm was fine enough to retain meiobenthic specimens quantitatively. When the whole benthos was divided into macro‐ and meiofauna, the size distributions overlapped considerably in a mesh‐size fraction between 1.0 and 0.5 mm. In this fraction, the meiofauna predominated over macrofauna in the deep sea, while the opposite applied to the shallower depths. From these results, recommended mesh sizes of the sieves for the studies of macro‐ and meiobenthos we

ISSN:0020-9309    

DOI:10.1002/iroh.19890740102

出版商:Akademie Verlag, Berlin    

年代:1989

数据来源: WILEY

摘要:

AbstractPlanktonic herbivores forage on phytoplankton cells which were produced at some earlier time and at a distant place. A steady state, one dimension model of the birth, death and eddy diffusion of phytoplankton illustrates phytoplankton smooth both temporal and spatial variations as they are transported. When the eddy diffusivity iskand the phytoplankton doubling time isb, the average distance traveled by a phytoplankton cell is (kb)1/2and the average time spent doing so isb. Only those spatial variations with wavelengths greater than 2π(kb)1/2and temporal variations with periods greater than 2πbwill be observed in the phytoplankton distributions at more than half their original amplitude. Bothkandbcontrol the length scale of phytoplankton distributions in a cartesian coordinate system. Planktonic herbivores view the phytoplankton from a diffusing coordinate system in which the spatial scales of the phytoplankton distribution are transformed into time scale

ISSN:0020-9309    

DOI:10.1002/iroh.19890740103

出版商:Akademie Verlag, Berlin    

年代:1989

数据来源: WILEY

摘要:

AbstractThe annual cycles of nutrients in the Etang de Berre were studied in 1985. From measurements twice a month at the input points, daily data for the freshwater flow and from daily measurements at the output point, an estimation is proposed for a nutrient budget. Seasonal variability is important, and a biological control of nutrient availability (locally remineralized products) results in a hydrologically controlled system (nutrients carried by continental waters) which produces the very high microalgal biomass observed in the lagoon. The seasonal halocline brings the euphotic layer very close to the remineralization site: nutrients are then constantly available to the phytoplankton.

ISSN:0020-9309    

DOI:10.1002/iroh.19890740104

出版商:Akademie Verlag, Berlin    

年代:1989

数据来源: WILEY

摘要:

AbstractA laboratory investigation was conducted to study the effect of various concentrations of copper on the freshwater algaeScenedesmus quadricaudaandChlorella vulgaris. Electron‐dense inclusions were observed in the vacuoles ofS. quadricauda, and this alga showed some growth at a dose as high as 2,500 μg.1−1. The occurrence of the electron‐dense inclusions was correlated significantly with the copper concentration and seems to be implicated in the tolerance of the species.C. vulgariswas much more sensitive to copper thanS. quadricaudaand showed osmotic changes and membrane

ISSN:0020-9309    

DOI:10.1002/iroh.19890740105

出版商:Akademie Verlag, Berlin    

年代:1989

数据来源: WILEY

摘要:

AbstractIn insular Newfoundland, wild anadromous juvenile Atlantic salmon make extensive use of lacustrine habitat for rearing. Smolt production was determined for a portion of a river system where virtually all rearing habitat is lacustrine. Production in terms of lacustrine habitat was estimated to be 10.1 smolts‐ ha−1. Smolt production is discussed in relation to morphometric characteristics. A comparison is made with smolt production obtained from stockings of swim‐up fry directly into lakes in another insular Newfoundland river s

ISSN:0020-9309    

DOI:10.1002/iroh.19890740106

出版商:Akademie Verlag, Berlin    

年代:1989

数据来源: WILEY

摘要:

AbstractA general description is given of major Central Asian canals and their differences in age, morphometry, flow feed, total dissolved solids, thermal regime, transparency as well as algal flora and its quantitative development.

ISSN:0020-9309    

DOI:10.1002/iroh.19890740107

出版商:Akademie Verlag, Berlin    

年代:1989

数据来源: WILEY

摘要:

AbstractThe biokinetic zones ofC. fernandoi, C. simoniandC. pristiswere found to be 15–29 °C, 15–27 °C and 13–27 °C respectively, while their respective ranges of distribution were found to be in altitudes of 0–700, 0–700 and 450–850 m. Their responses to low temperatures indicate that all three species are unlikely to occur above 1,000 m. The lower limit of distribution ofC. fernandoiandC. simoniextends to altitudes in which the temperature rises above their ultimate upper incipient lethal temperatures (UILT). They appear to avoid high temperatures by moving into cooler waters.C. pristiscannot do so since it lives in very shallow streams; the lower level of its distribution appears therefore to be limit

ISSN:0020-9309    

DOI:10.1002/iroh.19890740108

出版商:Akademie Verlag, Berlin    

年代:1989

数据来源: WILEY

摘要:

AbstractThe phytoplankton species composition and community structure were studied at two stations in the Vellar estuary from January to December, 1983. A total of 117 species of phytoplankton belonging to various groups, namely diatoms (90), dinoflagellates (21), Chlorophyceae (3), Cyanophyceae (2) and silicoflagellates (1) were observed during the study. The species diversity, richness and evenness values varied from 0.7 to 4.2 units/individual, 0.9 to 5.7 and 0.19 to 0.75 respectively. Dominance index values varied between 32.6 and 96.4 during the study period.

ISSN:0020-9309    

DOI:10.1002/iroh.19890740109

出版商:Akademie Verlag, Berlin    

年代:1989

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19890740111

出版商:Akademie Verlag, Berlin    

年代:1989

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19890740113

出版商:Akademie Verlag, Berlin    

年代:1989

数据来源: WILEY