The Comparative Effects of Fresh-Water and Marine Teleost Pituitary on the Water Balance of Frogs

Copeia ◽  
1958 ◽  
Vol 1958 (2) ◽  
pp. 86 ◽  
Author(s):  
George F. Weisel
Keyword(s):  
Water Balance ◽  
Fresh Water ◽  
Marine Teleost

Fresh water balance of the Gulf Stream system in a regional model study

2001 ◽  
Vol 18 (1-2) ◽  
pp. 17-27 ◽  
Author(s):  
R. Gerdes ◽  
A. Biastoch ◽  
R. Redler
Keyword(s):  
Water Balance ◽  
Fresh Water ◽  
Gulf Stream ◽  
Regional Model ◽  
Model Study ◽  
Stream System

Impacts cumulatifs du développement hydro-électrique sur le bilan d'eau douce de la baie d'Hudson

1994 ◽  
Vol 21 (2) ◽  
pp. 297-306 ◽  
Author(s):  
François Anctil ◽  
Richard Couture
Keyword(s):  
Water Balance ◽  
Fresh Water ◽  
Marine Environment ◽  
Mass Exchange ◽  
Spatial Scales ◽  
Ice Cover ◽  
Hudson Bay ◽  
Freezing And Thawing ◽  
Runoff Water ◽  
Hydroelectric Development

This paper discusses the consequences on the marine environment, more specifically on the fresh water balance, of the hydroelectric development of several tributaries of Hudson Bay, including James Bay and Foxe Basin. The fresh water balance is determined by identifying, at different scales, the modifications caused by each complex. The main inputs are the freezing and thawing of the ice cover, runoff water, and mass exchange at the air–water interface. Three spatial scales were used to obtain the resolution required to document the cumulative effects of fresh water balance modifications on the water surface layer: the Hudson Bay, the Hudson Strait, and the Labrador Sea. Finally, the addition of the proposed Grande-Baleine hydroelectric complex is examined from the available information and forecasts. Key words: hydroelectric development, impact, marine environment, fresh water balance, ice cover, runoff water, mass exchange.[Journal translation]

Salt and Water Balance in Salmon Smolts

1970 ◽  
Vol 52 (3) ◽  
pp. 553-564
Author(s):  
W. T. W. POTTS ◽  
MARGARET A. FOSTER ◽  
J. W. STATHER
Keyword(s):  
Water Balance ◽  
Fresh Water ◽  
Sodium Pump ◽  
Sea Water ◽  
High Rate ◽  
Exchange Diffusion ◽  
Rapid Changes ◽  
Alternative Hypotheses ◽  
Salt And Water Balance

1. Salmon smolts adapted to sea water maintain a high rate of turnover of both sodium and chloride, but when adapted to fresh water the rate of turnover is low. 2. Only a small part of the influx takes place through the gut. 3. On immediate transfer from sea water to dilute sea water or to fresh water the influxes decline rapidly, but on transfer from fresh water to sea water the restoration of the fluxes takes place slowly. 4. The alternative hypotheses that the rapid changes are due to exchange diffusion or to rapid adjustments of the sodium pump are discussed.

scholarly journals River for Jaffna-Cultivating Productive Water from Salt Water Lagoons in Northern Sri Lanka-What the Water Balance of Elephant Pass Lagoon Demonstrates

2016 ◽  
Vol 07 (02) ◽  
pp. 137-143
Author(s):  
Kuganesan, S ◽  
Sivakumar, S.S
Keyword(s):  
Sri Lanka ◽  
Water Balance ◽  
Fresh Water ◽  
Salt Water ◽  
Productive Water ◽  
Increasing Demand

The proposal of converting Jaffna salt water lagoons in northern Sri Lanka to fresh water lakes is revived again in the recent days due to the increasing demand and dearth of fresh water in this region. Jaffna lagoon consists of two internal lagoons in the Jaffna peninsula and the external lagoon, Elephant pass.

The role of environmental calcium in freshwater survival of the marine teleost, Lagodon rhomboides

1976 ◽  
Vol 65 (3) ◽  
pp. 529-538
Author(s):  
J. C. Carrier ◽  
D. H. Evans
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Chelating Agent ◽  
Marine Teleost ◽  
Lagodon Rhomboides ◽  
Na Efflux ◽  
Total Body ◽  
Na Uptake ◽  
Marine Teleost Fish

(1) The marine teleost fish, Lagodon rhomboides, can only tolerate fresh water (5 mM Na) if Ca is also present (10 mM). Transfer to Ca-free fresh water is followed by a substantial increase in radioactive Na efflux with little or no change in the transepithelial potential. Addition of the chelating agent EDTA (2 mM) further increases Na efflux. Fish left in Ca-free fresh water for 2-5 h die with a total body Na less than 50% of that found in animals acclimated to Ca-supplemented fresh water. (2) Rates of Na uptake were measured on either sea-water-acclimated or Ca-supplemented fresh water-acclimated fish transferred to various low Na media. In both cases Na uptake has a high Km, is saturable, inhibited by external NH4, H and amiloride, and is not related to changes in the trans-epithelial potential. (3) It is suggested that L. rhomboides is dependent upon external Ca to decrease diffusional Na loss in low salinities so that a relatively inefficient Na uptake can balance diffusional and urinary Na loss.

Salt and water balance of modern baleen whales: rate of urine production and food intake

2003 ◽  
Vol 81 (4) ◽  
pp. 606-616 ◽  
Author(s):  
M Kjeld
Keyword(s):  
Water Balance ◽  
Creatinine Clearance ◽  
Fresh Water ◽  
Marine Mammals ◽  
Control Mechanisms ◽  
Creatinine Concentration ◽  
Baleen Whales ◽  
Terrestrial Mammals ◽  
Urine Production ◽  
Salt And Water Balance

Whales, as pelagic marine mammals, are thought to have evolved from fresh-water-dependent terrestrial mammals. Baleen whales feed primarily on salty euphausiids (krill) and have no access to fresh water. How have these mammals adapted to lifelong habitation in a hyperosmotic medium? A new approach is proposed for studying this by using allometry (scaling) of endogenous creatinine clearance in mammals together with determinations of creatinine concentration in fresh postmortem blood and urine of fin whales (Balaenoptera physalus) and sei whales (Balaenoptera borealis). From the predicted mean creatinine-clearance values and the measured mean creatinine concentrations, a urine-production rates of 974 and 627 L/day for the fin and sei whales, respectively, were computed. Average daily krill ingestion of about 1300 and 835 L is predicted for the fin and sei whales, respectively. The whales seem to ingest about 30% more than earlier reported of a prey, which has about 50% of the salt concentration of seawater, thus maintaining the salt and water balance with a minimum of 1–2% seawater ingestion. The method used to estimate the above volumes could be a valuable tool in further studies of the water and salt balance of the large baleen whales, which may not have the same osmoregulatory control mechanisms as the smaller Odontoceti.

scholarly journals Sodium and Water Balance in the Cichlid Teleost, Tilapia Mossambica

1967 ◽  
Vol 47 (3) ◽  
pp. 461-470 ◽  
Author(s):  
W. T. W. POTTS ◽  
M. A. FOSTER ◽  
P. P. RUDY ◽  
G. PARRY HOWELLS
Keyword(s):  
Water Balance ◽  
Fresh Water ◽  
Sea Water ◽  
Tritiated Water ◽  
Sodium Influx ◽  
Water Drinking ◽  
Body Sodium ◽  
Total Body ◽  
Sodium And Water Balance ◽  
Total Sodium

1. The total body sodium increases from 45.9 µM/g. fish in fresh water to 59.9 µM/g. fish in 200 % sea water. 2. The rate of exchange of sodium increases from 2 µM/g./hr. in fresh water to 60 µM/g./hr. in 100% sea water. 3. The rate of drinking increases from 0.26%/hr. fresh water to 1.6%/hr. in 400% sea water. Even in 200% sea water drinking accounts for only a quarter of the total sodium influx. 4. The permeability to water, as measured by tritiated water, is highest in fresh water and lowest in 200% sea water. The permeabilities to water measured in this way are consistent with the drinking rates determined in sea water and 200% sea water.

scholarly journals Salt and Water Balance in the East African Fresh-Water Crab, Potamon Niloticus (M. Edw.)

1959 ◽  
Vol 36 (1) ◽  
pp. 157-176 ◽  
Author(s):  
J. SHAW
Keyword(s):  
Water Balance ◽  
Fresh Water ◽  
Sea Water ◽  
Freezing Point ◽  
Salt Content ◽  
The Body ◽  
Sodium Balance ◽  
East African ◽  
Sodium Loss ◽  
Salt And Water Balance

1. The mechanisms of salt and water balance in the East African fresh-water crab, Potamon niloticus, have been investigated. 2. The freezing-point depression of the blood is equivalent to that of a 271 mM./l. NaCl solution. 3. The animals cannot survive in solutions more concentrated than 75% sea water. Above the normal blood concentration, the blood osmotic pressure follows that of the medium. 4. The urine is iso-osmotic with the blood and is produced at a very slow rate. The potassium content is only half that of the blood. 5. The animal loses sodium at a rate of 8 µM./10 g./hr. mainly through the body surface. Potassium loss occurs at one-sixteenth of this rate. 6. Sodium balance can be maintained at a minimum external concentration of 0.05 mM./l. Potassium requires a concentration of 0.07 mM./l. 7. Active absorption of both sodium and potassium occurs. The rate of uptake of sodium depends on the extent of previous sodium loss. The rate of sodium uptake may be affected by such environmental factors as the salt content of the water, temperature and oxygen tension. 8. The normal oxygen consumption rate is 0.72 mg./10 g./hr. A minimum of 2.3% is used in doing osmotic work to maintain salt balance. 9. The salt and water balance in Potamon is discussed in relation to the adaptation of the Crustacea to fresh water. The importance of permeability changes is stressed.

scholarly journals Assessment of River Water Inflow into the Sasyk Estuary-Reservoir According to RCP4.5 and RCP8.5 Climate Change Scenarios for 2021-2050

2021 ◽  
Vol 30 (2) ◽  
pp. 315-325
Author(s):  
Nataliia S. Loboda ◽  
Yurii S. Tuchkovenko ◽  
Mykhailo О. Kozlov ◽  
Iryna V. Katynska
Keyword(s):  
Climate Change ◽  
Water Management ◽  
Water Balance ◽  
Fresh Water ◽  
21St Century ◽  
Freshwater Inflow ◽  
Climate Change Scenarios ◽  
Natural Conditions ◽  
Management Activity

The paper relevancy is determined by the need to substantiate the feasibility of restoring the ecosystem of the Sasyk estuary after its transformation into a reservoir (1978) and the unsuccessful desalination by the Danube waters for irrigation purposes. The paper is aimed at assessment of the possible inflow of fresh water to the Sasyk estuary from the Kohylnyk and Sarata rivers and their role in the formation of fresh water balance in the first half of the 21st century according to the climate change scenarios RCP4.5 and RCP8.5. The main calculation method is the ‘climate-runoff’ model, which uses meteorological data as input data. Estimates of freshwater inflow into the estuary-reservoir are provided for various calculation periods: before 1989 (before the beginning of significant climate change in the North-Western Black Sea Region); in the period of 1989-2018 according to the hydrometeorological observations; in 2021-2050, according to the averaged data from 14 runs of scenarios RCP4.5 and RCP8.5 under the EVRO-CORDEX project. Estimates of the average long-term values of freshwater inflow in natural conditions and the conditions transformed by water management activity were obtained for each calculation period. It is found that owing to changes in the regional climate for the period of 2021-2050, the total inflow of freshwater from rivers to the estuary in natural conditions will decrease by 23.5 % (by RCP4.5) and by 38.5 % (by RCP8.5) in comparison with the reference period (before 1989). Taking into account the impact of artificial reservoirs, the reduction in the river runoff will be 52.1 % (by RCP4.5) and 64.7 % (by RCP8.5). It is defined, that in case of renaturalization of the Sasyk reservoir into the estuary and the water inflow cut-off from the Danube river, the changes in climatic conditions expected in the first half of the 21st century, combined with water management activity, will result in the increased deficit of annual freshwater balance of the Sasyk reservoir up to 62 % under the RCP4.5 scenario and up to 75 % under the RCP8.5 scenario compared to the period before the emergence of climate change (before 1989). This change must be considered in scientific substantiation of the project on a reversion of the Sasyk Reservoir to the original status of the estuary to ensure such conditions of water exchange with the sea (for compensation of the water balance deficit), which will prevent the long-term trend of salinization.

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