摘要:

Abstract.Seasonal changes in phytoplankton species composition and abundance were studied in the Rias de Arosa and Muros (NW Spain) in November 1975, April and August 1976. Data on density and percentage contribution of species were used to calculate spatial and temporal relationships of phytoplankton communities by affinity matrices. The phytoplankton communities of both rias differed in species composition and abundance during the three sampling seasons. Diatoms dominated and total abundance was always higher in Arosa. Both rias have upwelling of nutrient‐rich oceanic water but the Arosa has an intense raft aquaculture of the edible musselMytilus eduli

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1982.tb00101.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Abstract.The frequency of parasitism of free ending prop roots of the red mangrove,Rhizophora mangle,by the wood boring isopodSphaeroma terebrans,increased with increasing distance of the endings to established roots. In a field experiment, in which isolated endings were, surrounded by wooden sticks, the endings were colonized byS. terebransat a lower rate than control endings, thus indicating that the wooden structures in the vicinity of the ending tended to reduce colonization rate byS. terebrans.It is concluded thatS. terebransmay cause mangrove root density to increase by colonizing peripheral endings more readily than endings which are near established roots.

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1982.tb00102.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Abstract.Benthic samples were taken at 26 stations during a two year period (1975–1977) in the Gulf of Thermaïkos, Greece. The topography and relevant physicochemical characteristics of the area are presented and discussed. Both density and biomass increase towards the northern limits in the Bay of Thessaloniki and in the Gulf of Thermaïkos, the difference between them being the degree of change in a north‐south direction. Analyses of the degree of concurrence of the dominant species show the existence of a number of groups of concurrent dominant species with characteristic distributional patterns and differing areal coverage in the study area. The observed quantitative and qualitative differences in the benthos are causally related to the differing environmental conditions prevailing in the two sub

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1982.tb00103.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Abstract.Using data from studies on alga‐dwelling harpacticoid copepods from New Zealand and Britain and shallow water decapods from a variety of habitats in the Pacific and Caribbean, an analysis is made of the contribution of physical and biotic habitat structures to the generation and maintenance of crustacean species richness. The relation between the number of species and the complexity of the habitat is, in equilibrium communities, positive and essentially linear. Accordingly, Gray's(1979) and Stenseth's(1979) theoretical predictions are endorsed whereby species‐abundance curves are, at equilibrium, expected to follow a log‐normal distribution, whereas departures from the log‐normal are anticipated in disturbed environments. Such departures reflect either increased dominance or inequalities in the species‐abundance hierarchy. Because of their adaptable life‐history traits, certain opportunist species are identified as those contributing most to departure points. The impact on community equilibrium of natural disturbance processes such as turbidity, exposure, and substratum transience

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1982.tb00104.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Abstract.Posidonia oceanicaprairies have been studied and mapped around the Island of Ischia and in adjacent waters. Prairies were found to cover an area of 15.7 km2and to be distributed between 0.5 and 39 m depth. The observed distribution is comparable to those reported by previous authors indicating that prairies have not undergone remarkable regressions in the last 50 years. Patterns recorded within the beds and at their lower limits, as indicated also by their sediments characteristics, are correlated to hydrodynamic energy. Two main types of water motion are responsible for the different types of erosive features: a) steady currents flowing parallel to the coast; b) rip‐, wave induced currents flowing normal to the coas

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1982.tb00105.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Abstract.The Adriatic brown macroalgaFucus virsoides(DON.) J. Ac(Fucales, Phaeophyceae)was investigated with particular respect to basic physiological features such as photosynthesis, dark carbon fixation, and respiration. Values obtained are expressed in various reference systems. Chemical composition of the fronds and physiological activity (photosynthesis/dark fixation along with the respective carboxytating enzymes (ribulose‐1,5‐bisphophate carboxylase and phosphoenol‐pyruvate carboxykinase) show longitudinal profiles. Temperature characteristics of photosynthesis in long‐term adapted specimens indicate reduced productivity at temperatures exceeding 20 °C. Photosynthesis during atmospheric exposure is markedly increased under moderate desiccation. Photosynthetic rates steadily decline under reduced salinity of the incubation medium, while respiration is stimulated. Net primary productivity of aF. virsoidesstand at 15 °C ambient average temperature, tidal exposure for maximally 2–3 hours and light‐dark regime = 12: 12 is calculated as 4.8‐5.4 g C m‐2d‐1. Culture experiments with polluted incubation media provide evidence that excessive nutrients including nitrate and phosphate as well as high concentrations of heavy metals (Zn, Co, Mn) cause severe growth‐rate reduction which may account for the steady decrease ofF. virsoidesin its natural habitat. The results are discussed with emphasis on the autecology ofF. virsoidesand its relationships to Atlantic represe

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1982.tb00106.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

Book reviewed in this article:Immelmann, K.: Wörterbuch der Verhaltensforschung. Verlag Paul Parey, Berlin and HamburgLevinton, J.S.: Marine Ecology. Prentice‐Hall Inc., Englewood Cliffs, New Jer

ISSN:0173-9565    

DOI:10.1111/j.1439-0485.1982.tb00107.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY