The Antarctic runnel can be highly variable in space and time; however, this environment has provided aninteresting habitat for terrestrial algal colonization. The runnel of Reeve Hill, Casey Station (66°16.855′...The Antarctic runnel can be highly variable in space and time; however, this environment has provided aninteresting habitat for terrestrial algal colonization. The runnel of Reeve Hill, Casey Station (66°16.855′S, 110°31.045′E), Antarctica, which occurs intermittently only during the brief austral summer showed high colonization by microalgaedominated mainly by Cyanobacteria mats and diatoms. 9 freshwater microalgae species which includesOscillatoria frac-ta, Oscillatoriasp., Navicula muticopsis, Pinnularia borealis, Nitzschiasp., Prasiola crispa, Chlorococcumsp., Syene-chococcus aeruginosusandSyenechococcus maiorwere recorded during the study. The algal community in the runnel to beobserved closely resembles that in the larger running water ecosystems in the continent. However, intrusion of seawater,direct exposure to sunlight and influence of sea current in the lower part changes the species community. The lower run-nel showed total dominance consists mainly of the marine planktonic Bacillariophycea. Other species detected includes Flagilaria kerguelensis, Flagilaria linearis, Eucampia antarctica, Thalassiosira tumida,Pseudonitzschia lineola, Pseud-onitzschia turgiduloides, Achnanthes brevipesand Odontella litigiosa. Lower algal species diversity observed in this studysuggests that the number of species obtained is related to the area of environment from which the samples were derived.The local assemblages simply contain species that is favored by the environmental conditions.展开更多
A study has been conducted on the status of water quality in two disused man made lakes, which have potential for cage aquaculture project. This study highlights the quality of water analyzed with reference to various...A study has been conducted on the status of water quality in two disused man made lakes, which have potential for cage aquaculture project. This study highlights the quality of water analyzed with reference to various physical-chemical parameters in two selected lakes and their suitability for fish farming. A number of parameters were measured including the amount of NH_ 3 -N, NO_ 3 -N, NO_ 2 -N and total phosphorus while in-situ measurement including DO, pH, temperature, conductivity, TDS and Secchi disk visibility. Beside the physical-chemical of water, the location, morphometry and climate conditions were also investigated. The chemical data analyzed for six months indicated that Lake A and Lake B are characterized by relatively high DO, slightly neutral pH and low TSS. The concentration of NH_ 3 -N and NO_ 2 -N was very low (0.058 mg/L and 0.04 mg/L, respectively) and total phosphorus was usually in low concentration and sometimes would seem negligible. Besides, NO_ 3 -N occurred in slightly higher concentration ( 1.75 mg/L ). Results obtained indicated that the study site has high potentiality for development of inland fisheries practices.展开更多
文摘The Antarctic runnel can be highly variable in space and time; however, this environment has provided aninteresting habitat for terrestrial algal colonization. The runnel of Reeve Hill, Casey Station (66°16.855′S, 110°31.045′E), Antarctica, which occurs intermittently only during the brief austral summer showed high colonization by microalgaedominated mainly by Cyanobacteria mats and diatoms. 9 freshwater microalgae species which includesOscillatoria frac-ta, Oscillatoriasp., Navicula muticopsis, Pinnularia borealis, Nitzschiasp., Prasiola crispa, Chlorococcumsp., Syene-chococcus aeruginosusandSyenechococcus maiorwere recorded during the study. The algal community in the runnel to beobserved closely resembles that in the larger running water ecosystems in the continent. However, intrusion of seawater,direct exposure to sunlight and influence of sea current in the lower part changes the species community. The lower run-nel showed total dominance consists mainly of the marine planktonic Bacillariophycea. Other species detected includes Flagilaria kerguelensis, Flagilaria linearis, Eucampia antarctica, Thalassiosira tumida,Pseudonitzschia lineola, Pseud-onitzschia turgiduloides, Achnanthes brevipesand Odontella litigiosa. Lower algal species diversity observed in this studysuggests that the number of species obtained is related to the area of environment from which the samples were derived.The local assemblages simply contain species that is favored by the environmental conditions.
文摘A study has been conducted on the status of water quality in two disused man made lakes, which have potential for cage aquaculture project. This study highlights the quality of water analyzed with reference to various physical-chemical parameters in two selected lakes and their suitability for fish farming. A number of parameters were measured including the amount of NH_ 3 -N, NO_ 3 -N, NO_ 2 -N and total phosphorus while in-situ measurement including DO, pH, temperature, conductivity, TDS and Secchi disk visibility. Beside the physical-chemical of water, the location, morphometry and climate conditions were also investigated. The chemical data analyzed for six months indicated that Lake A and Lake B are characterized by relatively high DO, slightly neutral pH and low TSS. The concentration of NH_ 3 -N and NO_ 2 -N was very low (0.058 mg/L and 0.04 mg/L, respectively) and total phosphorus was usually in low concentration and sometimes would seem negligible. Besides, NO_ 3 -N occurred in slightly higher concentration ( 1.75 mg/L ). Results obtained indicated that the study site has high potentiality for development of inland fisheries practices.
