Influence Of Water Salinity Research Articles

Effects of water salinity on melatonin levels in plasma and peripheral tissues and on melatonin binding sites in European sea bass ( Dicentrarchus labrax)

Sea bass is an euryhaline fish that lives in a wide range of salinities and migrates seasonally from lagoons to the open sea. However, to date, the influence of water salinity on sea bass melatonin levels has not been reported. Here, we evaluated the differences in plasma and tissue melatonin contents and melatonin binding sites in sea bass under four different salinity levels: seawater (36‰), isotonic water (15‰), brackish water (4‰) and freshwater (0‰). The melatonin content was evaluated in plasma, whole brain, gills, intestine and kidney, while melatonin binding sites were analyzed in different brain regions and in the neural retina. Plasma melatonin levels at mid-dark varied, the lowest value occurring in seawater (102 pg/mL), and the highest in freshwater (151 pg/mL). In gills and intestine, however, the highest melatonin values were found in the seawater group (209 and 627 pg/g tissue, respectively). Melatonin binding sites in the brain also varied with salinity, with the highest density observed at the lower salinities in the optic tectum, cerebellum and hypothalamus (30.3, 13.0, and 8.0 fmol/mg protein, respectively). Melatonin binding sites in the retina showed a similar pattern, with the highest values being observed in freshwater. Taken together, these results reveal that salinity influences melatonin production and modifies the density of binding sites, which suggests that this hormone could play a role in timing seasonal events in sea bass, including those linked to fish migration between waters of different salinities for reproduction and spawning.

Influence of water salinity and altitude on the tolerance of amphibian early life stages to nitrite

Influence of water salinity and altitude on the tolerance of amphibian early life stages to nitrite

Infiltration tests on a granite/bentonite mixture: Influence of water salinity

A series of infiltration tests on a 70%/30% granite/bentonite mixture compacted at a dry density of 1.70 g/cm3 are reported and analysed. This mixture is proposed as backfill material in the Swedish concept for radioactive waste disposal. The tests have been carried out at laboratory temperature for different periods of time, between 10 and 100 days, and with two kinds of infiltration water, to check the influence of the salinity on the hydration behaviour. The water intake has been measured during the tests, and the distributions of water content, dry density and soluble salts of the material have been determined at the end of the tests. It has become patent the difficulty in accurately measuring these parameters in such heterogeneous materials. The influence of the permeant salinity on the intrinsic permeability of the material has been highlighted, as well as the swelling capacity of this mixture. The ionic species distribution depends on the kind of infiltration water and the duration of the test. Dissolution, advection and diffusion are the mechanisms identified.

Effects of Water Salinity on Growth and Survival of Common Eider (Somateria Mollissima) Ducklings

AbstractThe need for fresh water may affect growth and survival of young waterfowl, including ducklings of sea ducks that are routinely raised in coastal marine habitats. We studied the influence of water salinity on growth and survival of Common Eider (Somateria mollissima) ducklings collected from nests on Southampton Island, Nunavut, Canada, in July 2001 and 2002. In 2001, 50 ducklings were partitioned into five groups (n = 10) and assigned a water salinity treatment for 6.5 days. Treatments included fresh water (<1 ppt NaCl), brackish water (11 ppt or 21 ppt), seawater (33 ppt), and a mixed regime (<1 ppt for 12 h, followed by 33 ppt for six days). In 2002, the experiment was replicated twice with different ducklings. Overall, growth rates were negatively correlated, and mortality rates positively correlated, with water salinity: 3%, 17%, and 60% of ducklings died in the <1-ppt, 11-ppt, and 21-ppt treatment groups, respectively; and 100% died in the 33-ppt and mixed-regime groups. The results confirm that fresh water is required for growth and survival of Common Eider ducklings immediately after hatch, which suggests that sources of fresh water in brood-rearing areas are an important requirement for successful reproduction.

EFFECTS OF WATER SALINITY ON GROWTH AND SURVIVAL OF COMMON EIDER (SOMATERIA MOLLISSIMA) DUCKLINGS

Abstract The need for fresh water may affect growth and survival of young waterfowl, including ducklings of sea ducks that are routinely raised in coastal marine habitats. We studied the influence of water salinity on growth and survival of Common Eider (Somateria mollissima) ducklings collected from nests on Southampton Island, Nunavut, Canada, in July 2001 and 2002. In 2001, 50 ducklings were partitioned into five groups (n = 10) and assigned a water salinity treatment for 6.5 days. Treatments included fresh water (<1 ppt NaCl), brackish water (11 ppt or 21 ppt), seawater (33 ppt), and a mixed regime (<1 ppt for 12 h, followed by 33 ppt for six days). In 2002, the experiment was replicated twice with different ducklings. Overall, growth rates were negatively correlated, and mortality rates positively correlated, with water salinity: 3%, 17%, and 60% of ducklings died in the <1-ppt, 11-ppt, and 21-ppt treatment groups, respectively; and 100% died in the 33-ppt and mixed-regime groups. The results confirm...

Influence of water salinity on the properties of cemented tailings backfill

(2001). Influence of water salinity on the properties of cemented tailings backfill. Mining Technology: Vol. 110, No. 1, pp. 62-65.

Influence of Salinity and Dissolved Humic Acids on Pesticides Extraction from Water Using Solid-Phase Extraction Disks

The influence of water salinity and dissolved organic matter (DOM) on pesticide extraction recoveries using solid phase extraction disks was investigated. Eleven selected pesticides, belonging to different chemical groups were spiked at 1–5 μg/L in 500 ml distilled water containing sodium chlorine at 0, 5, 10, 15, 20, 25, 30 and 35 ‰ or humic acids at either 0, 1, 5, 10, 25, 50 and 100 mg/L dissolved organic carbon (DOC). Samples were prefiltered and their extraction was done by using C18 Empore solid phase extraction disks and filter aid glass beads. The pesticides eluted from the disks were analysed by gas chromatography with flame thermoionic detector (FTD) and mass selected detector (MSD) in the selected ion monitoring (SIM) mode. Higher recoveries of most pesticides were obtained as the water salinity increased from 0 to 35 ‰. Concentrations of DOC in humic acid had less effect on extraction efficiency, which was probably due to greater nonpolar interactions of pesticides to the charge-neutralized humic acid polymer.

The Influence of water salinity on the free amino acid concentration in muscle and hepatopancreas of adult shrimps, Penaeus japonicus

Variations of the total free amino acid (FAA) pool and the content of specific amino acids have been measured in the muscle and hepatopancreas of adult shrimps, Penaeus japonicus, acclimatized at five water salinities: 38, 32, 26, 20 and 14%‰ The FAA content is always higher in muscle than in hepatopancreas at all tested salinites. On the other hand, the hepatopancreas exhibits the highest concentrations of essential amino acids. Two steps in the evolution of FAA content can be observed, the first one regarding decrease in salinity from 38 to 20%‰ and the second one, when salinity goes below 20% °. The first step can be characterized by a 16% decrease of total FAA content in the muscle and a 36% increase in the hepatopancreas. In muscle, the variations are mainly due to changes in non-essential FAA content, whereas in the hepatopancreas, they are linked to variations in essential FAA content. The other step is characterized by a drastic increase in moisture and decrease in FAA content in both studied organs when water salinity is 14%‰ The total FAA content is about 40% lower in shrimps at 14% ° compared to 38%‰ seawater salinity. During adaptation, the FAA pool (mainly NEFAAs) of muscle seems to be directly related to osmoregulation, whereas in the hepatopancreas, its evolution seems to be linked with energy expenditure and protein synthesis. The results are evaluated in order to elucidate the role of FAA in intracellular osmoregulation and in relation to animal ecology.

Influence of water salinity on toxic effects of enolofos 50 and owadofos 50 on rainbow trout and trout spermatozoa

Influence of water salinity on toxic effects of enolofos 50 and owadofos 50 on rainbow trout and trout spermatozoa

Influence of water salinity on sheep performance while grazing on natural grassland and saltbush pastures

Merino sheep grazing a semi-arid natural grassland were given water containing 0.0, 1.2, 1.6 or 2.0 per cent (w/v) soluble salts and similar sheep grazing on saltbush (Atriplex vesicaria) were given water containing 0.0, 0.8, 1.2 or 1.6 per cent soluble salts. The saline water was made up from sodium chloride and magnesium sulphate to give an ionic concentration similar to that occurring in natural underground waters. On grassland, 1.2 per cent saline water was without effect on the sheep, 1.6 per cent water reduced weight and wool growth in the first year and 2.0 per cent water reduced both wool growth and body weight by a significant amount. The effects were confined to the summer period of November to March. On saltbush, the results for four years were essentially similar to those for sheep on the grassland, although the effects of 1.2 per cent and 1.6 per cent saline waters were more pronounced. However, in the fifth year when drought conditions prevailed, the effects of both these treatments were more severe Water intakes were up to 1 lday-1 higher on the saline water treatments than on the fresh water, except when water intakes of the sheep on saltbush were high (7-11 lday-1) and then water salinity reduced water intakes. It was concluded that water salinities up to 1.2 per cent on grassland and 0.8 per cent on saltbush will not affect sheep productivity. Higher concentration (up to 1.6 per cent on grassland and 1.2 per cent on saltbush) can be used for adult sheep when forage conditions are good.

The influence of water salinity and stage in life history on ion concentration of fish blood serum

(1) The Na, K, Ca, Mg concentration of blood serum have been studied in nearly 60 fish species from various waterbodies (the Neva, Lake Dal'nee, the Volga, Lake Baikal, the White Sea, the Black Sea, the Barents Sea etc.). In fishes (Cyprinidae, Percidae, Siluridae etc.) from fresh water (Lake Dal'nee, the Baikal, the Neva) with low 0.18–0.24 mEq/1 Na concentration Na content in blood serum was lower than in closely related species from fresh water (the Volga, Lyutoga River) with larger Na concentration–nearly 0.5–1 mEq 1. Blood serum of marine teleosts Na concentration (156–210 mEq/1) was higher than in migrating and freshwater species (90–174) mEq/1) and it did not depend on seawater salinity: Barents Sea–465, White Sea–255, Black Sea–227 mEq/1.(2) Rather a considerable specific variation of ion concentration was found in blood serum of fishes from different families living in the same water body (Lake Baikal: Cyprinidae 90–95 mEq/1, Percidae 114 mEq/1, Salmonidae 126–129 mEq/1 etc.; the Volga: Siluridae 139 mEq/1, Percidae 142–150 mEq/1, Clupeidae 174 mEq/1).(3) No relation has been detected between K, Ca and Mg concentrations in blood serum of fishes and the concentrations of these ions in the environment.(4) Na concentration in the blood serum of sockeye salmon juveniles (101 mEq/1) migrating seaward was less than in adult fishes (132 mEq/1) returning to the lake to spawn. Na concentration in the blood of non‐migrating salmonids (Oncorhynchus nerka adult residual 104 mEq/1, Salvelinus alpinus juvenile 140 mEq/1, adult residual 141 mEq/1) changed insig‐ nificantly during life history. Notable hypopotassemia was observed in spawning time in Salmonidae.(5) The comparison of blood serum ion concentration in males and females of fishes from different taxonomic groups (Acipenseridae, Salmonidae, Cyprinidae) showed no significant variation.