1000 resultados para Lake Silvaplana, Engadin, Switzerland
Resumo:
Five species of submerged vegetation Lagarosiphon ilicifolius, Najas pectinata, Vallisneria aethiopica, Ceratophyllum demersum and Potamogeton octandrus; 7 species of gastropods Melanoides tuberculata, Bellamya capillata, Biomphalaria pfeifferi, Bullinus tropicus, Cleopatra sp, and Lymnaea natalensis and 4 species of bivalves Corbicula africana, Caelatura mossambicensis, Mutela dubia and Aspatharia wahlbergii are correlated with environmental variables particularly slope and transparency, in Lake Kariba. A stepwise regression analysis further revealed interdependence between (Cleopatra sp., B. pfeifferi, L. natalensis, B. capillata, and V. aethiopica as well as between as between C. mossambicensis and L. ilicifolius and N. pectinata. The dependence of B. pfeifferi, L. natalensis, B. capillata, Cleopatra sp. on V. aethiopica and C. mossambicensis on L. ilicifolius and N. pectinata implies that a change in the biomass of the vegetation species may affect distribution and biomass of the faunal species.
Resumo:
The water quality in fish cages on Lake Kariba was studied. The Kruskal-Wallis test was used to determine whether the water quality parameters differed significantly among the cage-types (cage-type effect). Secchi disc readings ranged from 2 to 4 metres, while temperature ranged from 23 degree C to 29.5 degree C. The observed conductivity was between 98.7 mu S/cm and 102.3 mu S/cm. The pH was between 6.31 and 7.82. Concentrations of dissolved oxygen varied from 1.55 to 6.47 mg/l, while dissolved oxygen saturation ranged from 22.3% to 83.1%. Within the same month, temperature did not differ significantly among cages. Conductivity, pH, dissolved oxygen concentration and dissolved oxygen saturation differed significantly among the 3 cage-types. Temperature and pH levels in the cages were close to the optimum levels for the culture of cichlids. Sub-optimal levels of dissolved oxygen occurred occasionally in the octagonal cages.
Resumo:
The bibliography contains some 116 citations, including unpublished reports and manuscripts, regarding Lake Kariba. Most of the reports are from the Zambia/Zimbabwe SADC Fisheries and Lake Kariba Fisheries Research Institute. The citations are listed in alphabetical order according to author.
Resumo:
The findings are presented of a survey conducted on Lake Kariba in order to update the basic statistics of the inshore fishery from a previous survey conducted in 1993 and also to collect some socioeconomic data regarding the artisanal fishery. The 1998 frame survey provided information on fishers both for the whole fishery and per village and changes in numbers; socio-economic characteristics as well as the number of fishing units and gear are included.
Resumo:
The 1981 statistics of the open water fishery (sardine, Limnothrissa miodon , and tigerfish, Hydrocynus vittatus) and inshore fishery (cichlids, labeoa, mainly L. altivelis , distichoclids, mainly Distichodus schenga , tigerfish, H. vittatus , mormyrids, mainly Mormyrus longirostris and M. deliciosus , and catfish, Clarias gariepinus) in Lake Kariba are presented.
Resumo:
Statistics are presented for Zimbabwe's Lake Kariba fisheries for the year 1982, being divided into open-water and inshore fishery sectors.
Resumo:
Statistics are presented of the open water and inshore fisheries of Lake Kariba, the Zimbabwe side, for 1983.
Resumo:
Statistics are presented for the Zimbabwe fisheries of Lake Kariba for 1984, being divided into pelagic and inshore fishery activities.
Resumo:
Catch and effort data are given for the various pelagic and inshore fisheries of the Zimbabwe side of Lake Kariba for the period 1980-85.
Resumo:
Catch and effort data are given for the various pelagic and inshore fisheries of the Zimbabwe side of Lake Kariba for the period 1974-86.
Resumo:
Statistics are presented for the Zimbabwe fisheries in Lake Kariba for the year 1987. Fish landings, fish catches and catch/effort data are given for the pelagic and inshore fishery sectors.
Resumo:
Statistics are presented for the Zimbabwe fisheries in Lake Kariba for the year 1988. Fish landings, fish catches and catch/effort data are given for the pelagic and inshore fishery sectors.
Resumo:
Statistics are presented for the Zimbabwe pelagic and inshore fisheries of Lake Kariba, covering the period 1974-89. Data include total landings, total effort, catch per unit effort, monthly landings and monthly catch per unit effort for both sectors.
Resumo:
This statistical report covers catch records from the Zimbabwe part of Lake Kariba for the period 1974-1991. Landings, catches and fishing effort statistics are included for both the kapenta and the inshore artisanal fishing sectors.
Resumo:
This statistical report covers catch records from the Zimbabwe part of Lake Kariba for the period 1974-1992. Landings, catches and fishing effort statistics are included for both the pelagic and the inshore artisanal fishing sectors.