摘要:

AbstractThe energy assimilated by single individuals of aquatic animals throughout their life times and by populations and communities of aquatic animals during the growth season has been studied with due regard for the definitive weight of the single individual and the mean biomass of populations and communities. Energy assimilated throughout life by invertebrates of different systematic positions, definitive size and life duration is about 2.5 times as high as the energetic content of their definitive mass. The energy flow in populations of benthic animals is about 5 times as high as the seasonal average biomass, and in populations of planktonic animals it is 40 times as high. The energy flow in bottom communities is almost 10 times and in planktonic ones 35 times as high as the average seasonal biomass of communities. Specific production (P/Bcoefficient per 24 h) for communities of bottom animals was 0.013 per 24 h. The average value of theK2coefficient (net growth efficiency) calculated for an individual's life time is about 0.4 in populations of bottom animals, theK2for vegetation seasons is 0.26, and for communities it is 0.2 (per vegetation season). Increasing complexity of the biological systems is accompanied by an increase in the specific energy flow and a decline in the efficiency of food energy utilization for production.

ISSN:0020-9309    

DOI:10.1002/iroh.19830680102

出版商:Akademie Verlag, Berlin    

年代:1983

数据来源: WILEY

摘要:

AbstractFor thein situmeasurement of nitrogen fixation in lake sediments, we developed a method which assures the rapid saturation with acetylene of the whole enzyme pool in the sediment and maintains near intact physical, chemical and biological environment at the water‐sediment interface. On the basis of seasonal measurements, the annual nitrogen fixation in the sediment was estimated in four types of shallow water ecosystem: the Keszthely Basin, Lake Balaton: 4.7 g N m−2; Körös backwater reservoir: 6.5 g N m−2; a polycultural fishpond: 0.49 g N m−2; and a liquid manure oxidation fishpond: 0.61 g N m−2. The amount of nitrogen fixed in the sediment of the Keszthely Basin was close to the fixation in the water column, while that fixed in the sediment of Körös backwater reservoir was considerably greater.A multiple regression analysis was made on the basis of synoptic studies on the vertical distribution of nitrogen fixation in the sediment, the pH, Eh, and concentrations of organic N, NH4‐N, NO3‐N, and NO2‐N in the interstitial water. The results indicate that nitrogen fixation is related to the dep, the NH4‐N concentration, and the redox potential. The vertical distribution of nitrogen fixation cannot be explained in every case by the densities and distributional patterns of theAzotobacterandClostridiumpopulations. No correlation was observed between nitrogen fixation and total organic‐C in lake sediment. A surprisingly close correlation was found between plankton primary production and the sedimentary nitrogen fixation in these lakes (r= 0.85,y= 4.5X0.85). Short‐term (4 h)in vitrostudies revealed a glucose mediated increase of nitrogen fixation, but there was no NH4‐N inhibition detected during t

ISSN:0020-9309    

DOI:10.1002/iroh.19830680103

出版商:Akademie Verlag, Berlin    

年代:1983

数据来源: WILEY

摘要:

AbstractMeasurements of primary production by phytoplankton in four fish ponds over a period of one year revealed a distinct spatial variation in rate. The ponds were used for polyculture, monoculture, or a traditional system of fish culture. The rates of gross photosynthesis were highly correlated with temperature, free CO2, oxygen, inorganic nitrogen (NH4+, NO2−, and NO3−) and PO4‐P. It was shown by step‐wise multiple regression analysis that in the polyculture pond with a predominantly autotrophic metabolism, gross photosynthesis was the most significant factor correlated with fish growth. In another polyculture system in which the metabolism was mainly hetero‐trophic, the influence of the photosynthesis rate w

ISSN:0020-9309    

DOI:10.1002/iroh.19830680104

出版商:Akademie Verlag, Berlin    

年代:1983

数据来源: WILEY

摘要:

AbstractBased on 96 grab samples at 16 sites the composition and distribution of macrobenthic fauna were examined in a small coastal basin of lower Chesapeake Bay. Normal classification analysis of dominant species produced five site groups. Site groups were divided into clean sand sites, fine sand sites with varying amounts of silt‐clay, and mud sites. Dominant species of the clean group were primarily restricted to this sediment type, while the dominant species of the other groups were widespread in the study are

ISSN:0020-9309    

DOI:10.1002/iroh.19830680105

出版商:Akademie Verlag, Berlin    

年代:1983

数据来源: WILEY

摘要:

AbstractThe benthic oxygen demand and inorganic nutrient release have been investigated in the coastal zone of the Mid‐Atlantic Bight of the United States usingin situand ship‐board incubations to estimate fluxes across the sediment‐water interface. Oxygen demand ranged from ca. 70 ml m−2hr−1nearshore in warm (25°C) muddy sediments to ca. 4 ml m−2hr−1in cold (6°C), coarse‐grained sediments offshore. Ammonium ion flux was out of the sediments in all but 4 of 29 incubations, while nitrate was often found to be utilized within or on the sediments, decreasing in 10 of 29 incubations. Those locations with fluxes of nitrate out of the sediment had concentrations in the pore water that were generally high, sometimes up to several mM l−1. Nitrate fluxes were always well below those of ammonia, even where high almost equivalent concentrations of both NH4and NO3were found at the same locale.On George's Bank only 13 % of total N demand by the phytoplankton was estimated to be supplied by the benthos, whereas in New York Bight the supply amounted to 42 % of the demand. This difference can be attributed to higher pelagic biological and advective (mixing and upwelling) inputs to George's Bank compared to the relatively well stratified New York Bight in lat

ISSN:0020-9309    

DOI:10.1002/iroh.19830680106

出版商:Akademie Verlag, Berlin    

年代:1983

数据来源: WILEY

摘要:

AbstractAnnual internal growth banding ofArctica islandicahas shown that the species has a surprising longevity of up to 149 years as stated byTHOMPSON,JONESandDREIBELBIS(1980). The authors have compiled 100 values of valve height against age as reproduced in Figure 1. Visually gained growth curves have been added for single specimens that leave some doubt as to the existence of an inflexion point. In this paper a cross‐sectional evaluation of growth behaviour is carried out with nine funtions using nonlinear regressions. Five growth functions yield almost equally good results with a final valve height just below 100 mm. An inflexion point is either present in early youth or lacking altogether, depending on the growth function use

ISSN:0020-9309    

DOI:10.1002/iroh.19830680107

出版商:Akademie Verlag, Berlin    

年代:1983

数据来源: WILEY

摘要:

AbstractThe genusBosminacan be differentiated into four subgenera: 1.Bosminas. str.BAIRD, 1845, 2.EubosminaSELIGO, 1900, 3.NeobosminaLIEDER, 1957, and 4.SinobosminaLIEDER, 1957. Subgeneric discrimination is based upon several features of the females (postabdominal claw, serration of the mucro, patterns of the lateral head pores) and, mainly, upon certain differences in the morphology of the male (postabdomen and, according toLILLJEBORG1900,BURCKHARDT1924 andKOŘINEK1971, the first leg). The distribution of theBosminasubgenera throughout the world varies:Bosminas. str. is distributed worldwide (except for Australia?),Eubosminais holarctic,Neobosminahas been found in Africa, the neotropical zone, Australia and Oceania, andSinobosminaoccurs in East and South‐East As

ISSN:0020-9309    

DOI:10.1002/iroh.19830680108

出版商:Akademie Verlag, Berlin    

年代:1983

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19830680109

出版商:Akademie Verlag, Berlin    

年代:1983

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19830680112

出版商:Akademie Verlag, Berlin    

年代:1983

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19830680114

出版商:Akademie Verlag, Berlin    

年代:1983

数据来源: WILEY