A comparison of the protonephridia of fresh-water, brackish-water and marine specimens of Gyratrix hermaphroditus

1943 ◽  
Vol 72 (1) ◽  
pp. 167-181 ◽  
Author(s):  
George A. Kromhout
Keyword(s):  
Fresh Water ◽  
Brackish Water

scholarly journals Content of inorganic solutes in lettuce grown with brackish water in different hydroponic systems

2017 ◽  
Vol 21 (3) ◽  
pp. 150-155 ◽  
Author(s):  
Alide M. W. Cova ◽  
Fabio T. O. de Freitas ◽  
Paula C. Viana ◽  
Maria R. S. Rafael ◽  
André D. de Azevedo Neto ◽  
...  
Keyword(s):  
Fresh Water ◽  
Nutrient Solution ◽  
Brackish Water ◽  
Dry Matter ◽  
Dry Matter Production ◽  
Matter Production ◽  
Water Plant ◽  
Hydroponic Systems ◽  
Inorganic Solutes

ABSTRACT The objective of this study was to evaluate the growth and accumulation of ions in lettuce grown in different hydroponic systems and recirculation frequencies. The experimental design was randomized blocks with 8 treatments and 4 replicates. The evaluated hydroponic systems were Nutrient Flow Technique (NFT) and an adapted Deep Flow Technique (DFT), the latter with recirculation frequencies of 0.25, 2 and 4 h. Both systems used fresh water and brackish water. Plant growth, accumulation of inorganic solutes (Na+, K+, Cl- and NO3-) and the correlation between dry matter production and Na+/K+ and Cl-/NO3- were evaluated. The salinity of the water used to prepare the nutrient solution caused decrease in growth and K+ and NO3- levels, and increased contents of Na+ and Cl- in the plants. When using fresh water the highest dry matter production was obtained in the NFT system. In case of brackish water the adapted DFT system increased the production, in relation to NFT system (at same recirculation frequency: 0.25 h). It was found that the choice of the type of hydroponic system and recirculation interval for the cultivation of lettuce depends on the quality of the water used to prepare the nutrient solution.

XII.—The Brackish-water Lochs of North Uist

1937 ◽  
Vol 56 ◽  
pp. 169-195 ◽  
Author(s):  
A. T. Nicol
Keyword(s):  
Fresh Water ◽  
Brackish Water

About the year 1695 Martin Martin visited the Hebrides, and of the Island of North Uist he writes, “There is such a number of fresh water lakes here as can hardly be believed. … They are generally well stocked with trout and eels and some of them with salmon, and, which is yet more strange, cod, ling, mackerel, etc., are taken in these lakes into which they are brought by the spring tides.” This old reference suggested that the brackish-water fauna of the Hebrides might be of considerable interest and extent. Consequently I spent part of the summers of 1933 and 1935 in North Uist in order to study the fauna of the lochs and the conditions under which the animals were living.

Application of geothermal energy for heating and fresh water production in a brackish water greenhouse desalination unit: A case study from Algeria

2010 ◽  
Vol 14 (1) ◽  
pp. 512-517 ◽  
Author(s):  
Hacene Mahmoudi ◽  
Nawel Spahis ◽  
Mattheus F. Goosen ◽  
Noreddine Ghaffour ◽  
Nadjib Drouiche ◽  
...  
Keyword(s):  
Fresh Water ◽  
Brackish Water ◽  
Geothermal Energy ◽  
Water Production

scholarly journals Response of Water-Salt Migration to Brackish Water Irrigation with Different Irrigation Intervals and Sequences

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2089 ◽  
Author(s):  
Zhu ◽  
Yang ◽  
Sun ◽  
Zhang
Keyword(s):  
Fresh Water ◽  
Brackish Water ◽  
Irrigation Treatment ◽  
Water Infiltration ◽  
Laboratory Simulation ◽  
Irrigation Interval ◽  
Significant Difference ◽  
Soil Desalination ◽  
The Mean ◽  
Irrigation Treatments

Establishing methods for scientific and rational use of brackish water resources is the key to farmland irrigation in the Yellow River Delta region of China. In this study, we conducted laboratory simulation experiments with soil columns and monitored the changes in water infiltration and salt distribution under eight irrigation treatments, including four intervals (0, 30, 60, and 90 min between irrigations) and two sequences (brackish-brackish-fresh water and brackish-fresh-brackish water). The results showed that the duration of water infiltration into the soil was higher under intermittent irrigation than continuous irrigation, with the highest value recorded at the 90-min irrigation interval. There was no significant difference in the mean soil water content between the brackish-brackish-fresh water (28.01–29.71%) and brackish-fresh-brackish water (28.85–29.98%) irrigation treatments. However, the mean soil desalination rate of the brackish-brackish-fresh irrigation treatment (42.51–46.83%) was higher than that of the brackish-fresh-brackish irrigation treatment (39.48–46.47%), and a much higher soil desalination rate was observed at the 90-min irrigation interval, compared with the other intervals. In conclusion, brackish-brackish-fresh water irrigation at longer time intervals (e.g., 90 min between irrigations) is conducive to reduce soil salt content in the surface soil in the study region.

scholarly journals The Distribution of Gammarus Species in Estuaries. Part I

1947 ◽  
Vol 27 (1) ◽  
pp. 1-52 ◽  
Author(s):  
G. M. Spooner
Keyword(s):  
Fresh Water ◽  
Brackish Water ◽  
Field Work ◽  
Bottom Fauna ◽  
Qualitative Composition ◽  
British Isles ◽  
Free Swimming ◽  
The Status ◽  
Brackish Water Species ◽  
Water Species

The work of which an account is here given was largely carried out from the autumn of 1937 to the spring of 1940, when it was interrupted by the war. In taking it up again (in July 1945) while, facilities for field work are still limited, the author feels it useful to publish results as they stand and indicate where further work is considered advisable.In examinations of the free-swimming bottom fauna of the Tamar and other estuaries, attention was inevitably drawn to the populations of Gammarus species, which make up the greater bulk of it. Before quantitative observations were planned, some interesting points came to light with regard to the qualitative composition of populations. This aspect lent itself more readily to study and, though byno means a new field for exploration, soon proved worth examining ingreater detail than previous workers had attempted.The broad fact of a replacement of one Gammarus species by another in passing up an estuary was well enough known, though exact knowledge for the British Isles only starts from the time when G. zaddachi Sexton was recognized as a regular member of the upper estuarine fauna of the Tay (Bassindale, 1933; Alexander, Southgate & Bassindale, 1935) and of the Deben (Serventy, 1935). This species proved to be the main brackish-water species overlapping with the marine G. locusta (L.) near the seaward end, and with the fresh-water G. pulex (L.) at the river end (or ‘head’) of the estuary. The status in estuaries of two other brackish-water species, G. duebeni Lillj. and G. chevreuxi Sexton, remained obscure.

Research Progress on the Reduction and Utilization of RO Concentrated Brine from Desalination Plants

2013 ◽  
Vol 821-822 ◽  
pp. 1098-1101
Author(s):  
Wei Xing Li ◽  
Jing Huan Ma ◽  
Ying Liu ◽  
Qing Tong Ren ◽  
Zhan Sheng Ma
Keyword(s):  
Reverse Osmosis ◽  
Fresh Water ◽  
Brackish Water ◽  
Large Scale ◽  
Marine Ecosystems ◽  
Research Progress ◽  
Research Focus ◽  
Actual Application ◽  
Desalination Plants

Reverse Osmosis (RO) is an effective method to get fresh water from seawater or brackish water. The uncontrolled discharge of RO concentrated brine can contaminate water aquifers and damage marine ecosystems. The techniques to treat or utilize the rejected brine are the research focus in recent years. This paper tried to give an overview of latest development in this filed in order to provide references for its actual application in large-scale engineering.

The influence of salinity on Scirpus americanus tidal marshes in the St. Lawrence River estuary, Québec

1985 ◽  
Vol 63 (5) ◽  
pp. 920-927 ◽  
Author(s):  
J. Deschênes ◽  
J.-B. Sérodes
Keyword(s):  
Fresh Water ◽  
Lower Limit ◽  
Brackish Water ◽  
Saline Water ◽  
River Estuary ◽  
Considerable Effect ◽  
Tidal Marshes ◽  
Brackish Waters ◽  
Scirpus Americanus ◽  
St Lawrence River

The amount of sodium in the aboveground part of the stalks of Scirpus americanus taken at the peak of biomass is a good indicator of the amount of salinity in the waters flooding the tidal marshes of an estuary. In fresh water, the Na concentrations remain below 10 000 and then increase sharply up to 20 000 – 30 000 mg/kg in brackish waters. Even though this plant can grow under brackish conditions, salinity has a considerable effect on the percentage of submersion it can withstand. Consequently, in the presence of saline water, the lower limit of the vegetation regresses towards the shore. In the case of fresh water, Scirpus americanus occupies the lower part of marshes up to an average of 75% of submersion, while in brackish water it extends to about 35% and then disappears when waters are more saline.

Development of tools for assessing conservation categories of siluroid fishes of fresh water and brackish water wetlands of South West Bengal, India

2009 ◽  
Vol 84 (4) ◽  
pp. 395-407 ◽  
Author(s):  
Siddhartha Sankar Mishra ◽  
Sankar Kumar Acharjee ◽  
Susanta Kumar Chakraborty
Keyword(s):  
Fresh Water ◽  
Brackish Water ◽  
West Bengal ◽  
South West

scholarly journals Holocene development of the Arresø area, north-east Sjælland, Denmark.

2017 ◽  
Vol 65 ◽  
pp. 25-35
Author(s):  
Ole Bennike ◽  
Pernille Pantmann ◽  
Esben Aarsleff
Keyword(s):  
Fresh Water ◽  
Brackish Water ◽  
Water Phase ◽  
Ostrea Edulis ◽  
Land Area ◽  
Marine Fauna ◽  
North East ◽  
Acidic Waters ◽  
Area North ◽  
Alkaline Waters

The Arresø area in north-east Sjælland, Denmark, was deglaciated about 18,000 to 16,000 years ago. In the Holocene it was probably a land area until it was transgressed by the sea c. 8500 years BP. During a first marine phase the area housed a species-rich marine fauna that included the oyster Ostrea edulis, the salinity and water temperatures were higher than at present, and there was a wide connection to the Kattegat sea. At about 6500 years BP there was a short-lived lake or brackish-water phase, but marine conditions were soon re-established with a fauna less diverse than before, and both salinity and water temperatures decreased. The present lake Arresø became isolated from the sea about 2500 years BP. The transition from brackish water to fresh water was rapid; the lake developed from shallow alkaline waters to deeper more acidic waters and finally to eutrophic waters.

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