scholarly journals The Effects of Salinity Changes on the Respiratory Rate of the Prawn Palaemonetes Varians (Leach)

1956 ◽  
Vol 33 (4) ◽  
pp. 730-736 ◽  
Author(s):  
B. LOFTS
Keyword(s):  
Salt Marsh ◽  
Respiratory Rate ◽  
Sea Water ◽  
Saline Water ◽  
Salt Water ◽  
Tap Water ◽  
Drainage Ditches ◽  
Low Salinity ◽  
Salinity Changes ◽  
British Coast

1. Palaemonetes varians, variety microgenitor, commonly inhabits only saline water around the British coast. It is, however, abundant in water of extremely low salinity in the Cardiff area, where it occurs in the drainage ditches of farm land adjacent to an area of salt-marsh. 2. Animals from areas of both high and low salinity were subjected, in the laboratory, to a range of salinities varying from pure tap water to concentrated sea water. The rate of respiration at each salinity was measured. 3. The population that inhabited the almost fresh water in the ditches differed physiologically from the salt-water form, although morphologically they were identical. 4. The salt-water population showed a minimum respiratory rate when in a medium of 26% NaCl salinity. This was expected, since the animal is isotonic at this salinity and the osmoregulatory work is minimal. The second population respired least when in a medium of 6% NaCl. The significance of this is discussed.

The Effect of Salinity Changes on the Water Content and Respiration of Marine Invertebrates

1931 ◽  
Vol 8 (3) ◽  
pp. 211-227
Author(s):  
L. C. BEADLE
Keyword(s):  
Respiratory Rate ◽  
Marine Invertebrates ◽  
Sea Water ◽  
Oxygen Intake ◽  
Anaerobic Conditions ◽  
Marine Animals ◽  
Surrounding Water ◽  
Low Salinity ◽  
Initial Difference ◽  
Good Support

1. Schlieper's theory of the function of increased oxygen intake by "homoiosmotic" marine invertebrates in dilute sea water in maintaining their body fluids hypertonic to the surrounding water is discussed, and objections are brought forward to the methods used in the experiments on which his conclusions were based. 2. By periodic weighings, and measurements of respiratory rate (under narcotic) by Barcroft manometers, it was found that the weight of N. diversicolor, on transference to water of low salinity, at first increases and then falls, and that the respiratory rate is at first increased and later tends to decrease. 3. With N. cultrifera the weight increases to a higher value and does not sub sequently fall, and the respiratory rate is also increased but to a lesser extent than with N. diversicolor. 4. These differences in the amount of increase in respiratory rate are more marked in water containing only 16.6 per cent, sea water than in water containing 25 per cent, sea water. 5. N. diversicolor maintains its activity while N. cultifera becomes practically inert in dilute water. The latter does not actually die in 25 per cent, sea water after 100 hours, but dies in 16.6 per cent, sea water after about 50 hours. 6. Exposure to M/1000 KCN or to anaerobic conditions in dilute water tends to break down the mechanism by which the free osmotic inflow of water in N. diversicolor is prevented, and the weight curves under these conditions approach the N. cultrifera form. 7. The respiratory rate of G. ulvae increases progressively with dilution of the sea water, and is roughly proportional to the initial difference of osmotic pressure inside and outside the animal. 8. The swelling of Gunda in dilute water is due to swelling of the gut cells, which become much vacuolated. The other tissues appear unaltered. 9. M/1000 KCN or anaerobic conditions cause a greater amount of swelling in Gunda in a given salinity than normally occurs. 10. These experiments seem to give reasonably good support to Schlieper's hypothesis. 11. The mechanism responsible for this "osmotic resistance" in N. diversicolor must be of a somewhat different nature from that in G. ulvae. 12. A rigid distinction between "homoiosmotic" and "poikilosmotic" marine animals cannot be supported.

scholarly journals 908 PB 533 STUDIES ON NATURE OF SALT TOLERANCE IN OKRA

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 564b-564
Author(s):  
Kh. A. Okasha ◽  
R. M. Helal
Keyword(s):  
Salt Tolerance ◽  
Seed Germination ◽  
Plant Development ◽  
Sea Water ◽  
Saline Water ◽  
Tap Water ◽  
Total Yield ◽  
Gold Coast ◽  
Electronic Conductivities ◽  
High Level

Salt tolerance of four okra cutivars namely : white velvet ; Gold coast ; Balady and Eskandarani, were investigated during three different stages of plant development namely : seed germination, seedling and reproductive stages. At both first and second stages of plant development various concentrations of sea water (diluted with tap water) were used for irrigation while at the third stage, various saline water with different electronic conductivities were used for irrigation Results of these studies revealed that salinity reduced and delayed seed germination At this stage, white velvet cv. appeared to be tolerant to salinity. At the seedling stage, salinity generally reduced hash weight of plant for all tested cuitivars and Gold coast was the lead affected one At the reproductive stage, salinity reduced plant growth and total yield/plant but with different degrees depending upon cultivar In this respect, yield of both Gold coast and Balady was not greatly reduced at the high level of salinity The anatomical studies showed that salinity reduced xylem and phloem elements in okra roots depending upon both salinity level and cultivar Generally, the obtained results suggest that both Gold coast and Balady okra cultivars can considered as tolerant genotypes to salinity and recommended for cultivation in both and and semi-arid lands where salinity is considered a potential problem

scholarly journals Investigating interdecadal salinity changes in the Baltic Sea in a 1850–2008 hindcast simulation

2020 ◽  
Vol 16 (4) ◽  
pp. 1617-1642 ◽  
Author(s):  
Hagen Radtke ◽  
Sandra-Esther Brunnabend ◽  
Ulf Gräwe ◽  
H. E. Markus Meier
Keyword(s):  
Baltic Sea ◽  
River Runoff ◽  
Sea Water ◽  
Salt Water ◽  
Salinity Range ◽  
Historical Period ◽  
The Baltic Sea ◽  
High Salinity Water ◽  
Salinity Changes ◽  
The Baltic

Abstract. Interdecadal variability in the salinity of the Baltic Sea is dominated by a 30-year cycle with a peak-to-peak amplitude of around 0.4 g kg−1 at the surface. Such changes may have substantial consequences for the ecosystem, since species are adapted to a suitable salinity range and may experience habitat shifts. It is therefore important to understand the drivers of such changes. We use both analysis of empirical data and a numerical model reconstruction for the period of 1850–2008 to explain these interdecadal changes. The model explains 93 % and 52 % of the variance in the observed interdecadal salinity changes at the surface and the bottom, respectively, at an oceanographic station at Gotland Deep. It is known that the 30-year periodicity coincides with a variability in river runoff. Periods of enhanced runoff are followed by lower salinities. We demonstrate, however, that the drop in mean salinity cannot be understood as a simple dilution of the Baltic Sea water by freshwater. Rather, the 30-year periodicity in river runoff occurs synchronously with a substantial variation in salt water import across Darss Sill. Fewer strong inflow events occur in periods of enhanced river runoff. This reduction in the import of high-salinity water is the main reason for the freshening of the water below the permanent halocline. In the bottom waters, the variation in salinity is larger than at the surface. As a consequence, the surface layer salinity variation is caused by a combination of both effects: a direct dilution by river water and a reduced upward diffusion of salt as a consequence of reduced inflow activity. Our findings suggest that the direct dilution effect is responsible for 27 % of the salinity variations only. It remains unclear whether the covariation in river runoff and inflow activity are only a coincidental correlation during the historical period or whether a mechanistic link exists between the two quantities, e.g. whether both are caused by the same atmospheric patterns.

An SEM and EDS study of secretions from the leaves of two halophytes

1994 ◽  
Vol 52 ◽  
pp. 340-341
Author(s):  
Yougasphree Naidoo ◽  
Michael A. Gregory ◽  
Gonasagren Naidoo
Keyword(s):  
Salt Marsh ◽  
Nutrient Solution ◽  
Sea Water ◽  
Tap Water ◽  
Coarse Sand ◽  
Salt Glands ◽  
Sporobolus Virginicus ◽  
Crystalline Deposits ◽  
Saline Habitats ◽  
Intertidal Marshes

Salt glands are secretory organs that occur in several angiosperm families including the Plumbaginaceae and Poaceae. They are particularly prevalent on the leaves of plants growing in saline habitats where by the secretion of ions, they prevent toxic levels of salts from accumulating in their tissues. Whether different species of halophytes containing morphologically disparate glands preferentially secrete different cocktails of ions is not known. This question was addressed by employing SEM and EDS to determine the morphology and elemental constituents of crystalline deposits over the salt glands of two species of salt marsh halophytes: Limonium scabrum (Thunb.) Kuntze (Plumbaginaceae) and Sporobolus virginicus (L.) Kunth (Poaceae).The two halophytes, collected from intertidal marshes and cultivated in a mixture of coarse sand and compost (3:1 by volume) were irrigated daily with tap water and fertilised every two weeks with full strength Hoagland’s nutrient solution. Plants were watered weekly for 3 months with 50 mol m−3 NaCl supplied as diluted sea water.

The reduction in growth of Mytilus edulis in fluctuating salinity regimes measured using laser diffraction patterns and the exaggeration of this effect by using tap water as the diluting medium

1984 ◽  
Vol 64 (2) ◽  
pp. 401-409 ◽  
Author(s):  
Ll. D. Gruffydd ◽  
R. Huxley ◽  
D. J. Crisp
Keyword(s):  
Mytilus Edulis ◽  
Sea Water ◽  
Tap Water ◽  
Shell Growth ◽  
Extended Period ◽  
Domestic Water ◽  
Low Salinity ◽  
Water Shell ◽  
Diffraction Patterns ◽  
Domestic Water Supply

In experiments to investigate the effect of low salinity on growth in Mytilus edulis, unexpected depression of growth occurred, even in sinusoidal regimes falling to only 90% of the full salinity, when tap water was the diluting medium used. The effect of various additives to the domestic water supply on the growth of Mytilus was investigated. Chlorine and fluoride had no effect although fluoride (as sodium fluoride) inhibited faeces production in a 7-day experiment. Determinations of the level of copper in the laboratory's tap water showed these to be high enough to cause depression of growth even at low dilution levels. When distilled water or lake water was used to dilute the sea water, shell growth was not affected until a sinusoidal fluctuation reaching a minimum of 50% sea water was used. Such effect did not become significant until the mussels were kept in pure fresh water for an extended period in each cycle of sinusoidal salinity variations.

Gas exchange characteristics of bald cypress (Taxodiumdistichum L.): evaluation of responses to leaf aging, flooding, and salinity

1986 ◽  
Vol 16 (6) ◽  
pp. 1394-1397 ◽  
Author(s):  
S. R. Pezeshki ◽  
R. D. DeLaune ◽  
W. H. Patrick Jr.
Keyword(s):  
Stomatal Conductance ◽  
Saline Water ◽  
Salt Water ◽  
Net Photosynthesis ◽  
Salt Water Intrusion ◽  
Low Salinity ◽  
Bald Cypress ◽  
Leaf Aging ◽  
Before And After ◽  
Gas Exchange Characteristics

Bald cypress (Taxodiumdistichum L.) seedlings were subjected to flooding with saline water containing 0 to 8 parts per thousand (137 mequiv. L−1 NaCl) under controlled environment conditions. Imposition of flooding and salinity stresses was designed to simulate the increase in submergence and salinity level which Louisiana's extensive cypress forests are currently experiencing as a result of rapid subsidence. The effect of flooding and salt water intrusion on subsequent stomatal behaviour and net photosynthesis for leaves developed before and after salt exposure were measured. Flooding and salinity resulted in a substantial decrease in stomatal conductance and net photosynthesis in both young and old leaves. Leaf aging did not significantly affect stomatal conductance and photosynthesis. Only plants flooded with freshwater and those flooded with low salinity concentration produced new leaves with improved stomatal conductance and net photosynthesis, which suggests some stomatal and photosynthetic acclimation to flooding and low salinity for bald cypress. Increase in salinity, however, caused more extensive impact and greater reductions of stomatal conductance and net photosynthesis in both leaf ages.

scholarly journals THE OBITSDI RIVER WATER SCHEME AND IT'S SALINITY PROBLEMS

1966 ◽  
Vol 1 (10) ◽  
pp. 80
Author(s):  
Yasuo Miyake ◽  
Tsutomu Kishi ◽  
Junichi Takahashi ◽  
Tatsuya Ikeda
Keyword(s):  
River Water ◽  
Sea Water ◽  
Saline Water ◽  
Salt Water ◽  
Wind Effect ◽  
Approximate Theory ◽  
Field Observations ◽  
Reservoir Water ◽  
The Earth ◽  
Earth Embankment

In this paper, the authors describe the salinity problems and their solutions which were encountered in the Obitsui River Water Scheme. The salinity problems in this water scheme are caused by differnt origins; The one is seepage of the sea water through the earth embankment, and the other is the diffusion of the saline water from the reservoir bed. Laboratory experiments and field observations were performed to confirm the detailed design of the reservoir. It was found that the salinity concentration of the reservoir water could be controlled less than 500ppm m weight, when the earth embankment of 1,000m width was released. The another way of salinity control studied by the authors was the recharging channel. At the present stage of studies, the recharging channel is considered to be favourable. Finally, the wind effect on the mterfacial mixing of the salt and fresh water in a reservoir was studied. An approximate theory to calculate the mixing rate of the salt water was derived from the field observations.

scholarly journals Regulation of the Haemolymph in the Saline Water Mosquito Larva Aedes Detritus Edw

1939 ◽  
Vol 16 (3) ◽  
pp. 346-362 ◽  
Author(s):  
L. C. BEADLE
Keyword(s):  
Osmotic Pressure ◽  
Sea Water ◽  
Saline Water ◽  
Salt Water ◽  
Chloride Content ◽  
The Body ◽  
Distilled Water ◽  
Aedes Detritus ◽  
Salt Exchange ◽  
Water Species

1. The larvae of the mosquito Aedes detritus have been reported only from definitely saline waters. They have been found in water of salinity equivalent to c 10 % NaCl. 2. In the laboratory they were acclimatized with ease to distilled water, sea water (7 % Nacl), 3.5 % NaCl, and glycerol (3.5 % NaCl). They also show considerable resistance to N/20 NaOH, but less to N/20 KOH and N/50 HCl. They are unable to live permanently in solutions of the chlorides of potassium, calcium and magnesium of osmotic pressure equivalent to 3.5 % NaCl. 3. In sea water of varying salinity they can regulate both the total osmotic pressure and chloride content of the haemolymph. A rise from nil to 6.0 % NaCl in the osmotic pressure of the medium is reflected in an increase of from c. 0.8 % to 1.4 % NaCl in that of the haemolymph. 4. In hypotonic solutions and distilled water much chloride is lost, but this is compensated by an increase in the non-chloride fraction. In hypertonic sea water the rise in osmotic pressure is due to increase in the chloride fraction, the non-chloride fraction remaining constant. 5. From this and from experiments with non-electrolytes it is concluded that the larva is permeable to salts and to molecules as large as glycerol, and that the regulatory mechanism in hypertonic saline is concerned with compensation rather for penetration of salts than for loss of water by osmosis. 6. Ligature experiments suggest that this mechanism is the excretion of salt by the Malpighian tubes, but further proof is required. 7. Salt exchange with the environment takes place via the gut, the body surface being impermeable to salts and water. 8. The larvae are able to concentrate chloride from hypotonic solutions but not as effectively as fresh-water species and only when the chloride content of the medium is a little below that of the haemolymph. 9. The anal gills, as in all salt-water species, are very small and appear to be impermeable to salts and water. It is therefore concluded that they are not the seat of the chloride-absorbing mechanism. 10. The osmotic pressure of the haemolymph is trebled by treatment with glycerol (3.5 % NaCl), which must be mainly the result of penetration of glycerol. The larva will however live normally in this, and an important factor in the resistance to abnormal media is therefore the adaptability of the tissues to changes in the concentration and composition of the haemolymph. 11. The increase in the osmotic pressure of the haemolymph induced by hypertonic sea water and glycerol does not alter the amount of fluid in the tracheoles. This is discussed in relation to the possible mechanism for the absorption of the tracheole fluid.

scholarly journals Effect of Exogenous α-Tocopherol on Sweet Pepper Plants Irrigated by Diluted Sea Water

2017 ◽  
Vol 5 (4) ◽  
pp. 23
Author(s):  
Sahar S. Taha, Abdel Wahab M. Mahmoud, Mostafa M. Rad
Keyword(s):  
Sea Water ◽  
Foliar Application ◽  
Salt Water ◽  
Tap Water ◽  
Block Design ◽  
Foliar Spray ◽  
Sweet Pepper ◽  
Growth And Yield ◽  
Pepper Plant ◽  
Pepper Plants

Capsicum annum is one of the most cultivated summer crops in Egypt which is consider the most susceptible crop to harsh a biotic stresses as Salinity condition. Pots experiment was carried out at Faculty of Agriculture, Fayoum University, Egypt during two successive summer seasons of 2014 and 2015 to study the responsive of Sweet pepper (cv. California wonder) plants irrigated by diluted sea water (EC= 8.0 dSm-1) to foliar applications of 1 mM alpha-Tocopherol (α TOC). Four treatments were arranged in a randomized block design:1) plants irrigated by sea water (SW) and sprayed by tap water (TW), 2) TW for irrigation and α TOC for foliar spray, 3) SW for irrigation and α TOC for foliar spray and 4) the control (TW for irrigation and foliar spray). Pepper plants irrigated by sea water recognized significant reductions in growth parameters (leave number, leaf area, plant dry weight, Fruit number and Fruit yield). Results also showed that, foliar application of pepper plant with αTOC caused a notable upgrading in growth and yield under saline conditions. The maximum increased growth was obtained when plants irrigated by TW and sprayed by 1 mM αTOC. The foliar application of αTOC considerably boosted the activities of Superoxide dismutase (SOD), Catalase (CAT), Ascorbate peroxidase (APX) and Glutathione reductase (GR) of pepper plants contrasted to control treatment. The outcome of present experiment could be recommended for both new reclaimed lands suffering from salt water and regions exposure to salinity hazard in irrigated water.

scholarly journals Oviposition and Development of Anopheles coluzzii coetzee and Wilkerson in Salt Water

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
E. K. Nwaefuna ◽  
Ibalafake Ibisobia Bagshaw ◽  
F. Gbogbo ◽  
M. Osae
Keyword(s):  
Brackish Water ◽  
Sea Water ◽  
Saline Water ◽  
Salt Water ◽  
Egg Laying ◽  
Sub Saharan Africa ◽  
Anopheles Coluzzii ◽  
Media Effect ◽  
Sea Levels ◽  
Ovipositional Preference

Anopheles coluzzii is an important vector of malaria in sub-Saharan Africa particularly of the most dangerous malaria parasite. It completes its life cycle in water and a change in physicochemical properties particularly that of salinity of water may affect egg laying and perhaps the development of eggs to maturity. Studies have shown that climate change may alter the transmission of many vector-borne diseases in different parts of the world and global warming will also raise sea levels which will lead to an increase in saline and brackish water body in coastal areas. This study investigated the salinity tolerance level of An. coluzzii. It involved creation of artificial environments of different salinity gradients using rainwater and sea water and the subsequent exposure of the media to An. coluzzii for laying of eggs and development of larvae to adult. Anopheles coluzzii showed ovipositional preference for less saline media as there was significant negative correlation between number of eggs laid and salinity of oviposition media. Effect of salinity was evident in egg development and larval survival, as no egg hatched in >30% sea water, all L3 larvae died in >40% seawater, and the maximum seawater concentration for L4 survival was 30%. An LC50 of 17.51% (95% CI: 9.31–24.56)% and 23.4% (95% CI: 16.76–22.30)% were calculated for L3 and L4 larvae respectively. Adults emerging from fresh and low saline water of 10% seawater had greater energy reserve than those emerging from 20% and 30% seawater. Increasing salinity did not affect wing length of the emerging adult. Despite the increased stress on larval development, some individuals survived and went on to emerge as adults in conditions that seem to be representative of brackish water. This may imply that an increase in brackish water sites caused by rising sea levels might create more suitable breeding sites for this species.

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