摘要:

Abstract.The estuarine ecosystem of the Amvrakikos Gulf, a semi‐enclosed embayment of the Ionian Sea, was surveyed at 9 stations in June, 1980. Quantitative and qualitative relationships among the phytoplanktonic, zooplanktonic and benthic populations were examined and related to environmental parameters. It was found that quantitative maxima of each of the three components occurred at different stations. When stations were grouped according to a similarity index of each community, it could be shown that the stations were very similar with regard to phytoplankton and slightly less similar with regard to zooplankton. The stations differed considerably as far as the benthos is concerned. The phytoplankton also exhibited a lower species diversity (0.08‐0.82 bits‐indiv.‐1) than the zooplankton (1.08‐2.10 bits indiv.‐1) and the benthos (0.85‐5.06 bits indiv.‐1). Differences in salinity among stations showed no significant correlation with the abundance or species diversity of phytoplankton, zooplan

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1983.tb00296.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Abstract.Discs of lamina tissue excised fromLaminaria digitata, L. hyperboreaandL. saccharinawere unaffected by cutting. They photosynthesized at a constant rate for several days and increased in area and weight during prolonged bubble cultures at a rate comparable with that of plants on the shore.

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1983.tb00297.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Abstract.Photosynthetic and respiratory rates ofLaminaria digitata, L. hyperboreaandL. saccharinameasured at 10oC and 28.5mW cm‐2(1422 μE m‐2s‐1), irrespective of ambient conditions, showed a peak of photosynthetic potential in the spring. Adjustment of metabolic potentials to the rates expected at ambient temperatures shifted this peak to summer and early autumn. Annual carbon budgets, which appeared to be more sensitive to changes in respiratory load than in irradiance, indicated a considerable surplus over respiratory needs forL. digitataandL. saccharinabut a deficit forL. hype

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1983.tb00298.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Abstract.Octopus vulgarisconsumes at least 22 molluscan and several crab species in the Mediterranean off the coast of France. Collections of prey discards in octopus middens and in areas inhabited by octopuses revealed that molluscs comprise an estimated 80% of theO. vulgurisdiet. Octopus predation is probably an important source of mortality for many of these prey species, causing up to 60%of the mortality within the size ranges sampled.O. vulgarisdoes not selectively consume particular sizes of its three most important prey species, the bivalvesPilaria chioneandVenus verrucosaand the abaloneHaliotis tuberculata.Analysis of octopus drill holes on the two bivalve species showed that their locations were nonrandom, whereas the distribution of drill holes in the abalone was not distinguishable from random.

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1983.tb00299.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Abstract.Animal‐animal interactions are recognized as critical in benthic invertebrate recruitment. The hypothesis tested was that benthic recruitment is more successful in low densities of infaunal suspension feeders than in high densities. Densities of young hard clamsMercenaria mercenaria(L.) ranging from 82.5 to 330m‐2were placed in defaunated boxes of sand. The mean number of species, mean number of individuals, mean wet weight biomass, mean species richness and mean dominance index per sample were calculated per density of hard clams from May to October. The experiment did not support the hypothesis. It was concluded that feeding behaviour of dense populations ofM. mercenariadid not preclude successful recruitment of other benthic spec

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1983.tb00300.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Abstract.The behavioural ecology of certain northern Adriatic fishes was observed from January to April at a water temperature of 7–11oC. The fishes studied here do not migrate to deeper waters. Most of the benthic fishes show a similar distribution over the substrate in winter and in summer; in winter, however, they are very inactive and hide in the substrate. Suprabenthic fishes aggregate in littoral caves where they form dense, inactive, mixed aggregations. Certain hemipelagic and pelagic fishes join to form very dense aggregations at specific sites in the open waters of bays. Littoral predators display high feeding activity at a time when their prey is inactive. I present a hypothesis concerning possible implications of seasonally cyclic environmental temperatures for a sympatric community of non‐migrating fis

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1983.tb00301.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY

摘要:

Book reviewed in this article:Hempel, G. (Ed.): The Canary Current: Studies of an upwelling systemRichards, F. A. (Ed.): Coastal upwelling. Coastal and Estuarine Sciences 1

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1983.tb00302.x

出版商:Blackwell Publishing Ltd    

年代:1983

数据来源: WILEY