Journal articles on the topic 'Variation with salinity'
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Paskausky, David F. "Salinity variation." Physics Teacher 25, no. 2 (February 1987): 73. http://dx.doi.org/10.1119/1.2342160.
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Rimper, Joice R. T. S. L., Silvana D. Harikedua, and Veibe Warouw. "The size variation of rotifer Brachionus rotundiformis cultivated with different feed at 40 ppt salinity." AQUATIC SCIENCE & MANAGEMENT 7, no. 1 (September 21, 2019): 26. http://dx.doi.org/10.35800/jasm.7.1.2019.25043.
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Title (Bahasa Indonesia): Variasi ukuran rotifer Brachionus rotundiformisyang diberi pakan berbeda pada salinitas 40 ppt RotiferBrachionus rotundiformisis a group of zooplankton which is used by fish larvae for feeding to initiate their growth. This zooplankton is widely favored by marine fauna larvae because of its small size can fits well with various larval mouth; thus, it is easily preyed by larvae. This study aimed to determine the variation of rotifer B. rotundiformismorphometry if cultured with different feed at 40 ppt. The use of 40 ppt salinity is expected to provide a variable morphometric size because B. rotundiformishas a polymorphism property. Microalgae used as feed for rotifer B. rotundiformiswere Prochloronsp. and Nanochloropsis oculata. Microalgae were cultured with Hirata medium. In the early stages, B. rotundiformiswas cultured at optimum temperature (28 ºC) and salinity 20 ppt, then it was cultured at salinity 40 ppt. Salinity adaptation was done by raising the salinity of the medium by 2 ppt every two days in a 10 ml reaction tube containing 10 individuals. After adaptation, B. rotundiformiswas transferred in a 1000 ml container with a density of 50 individuals. For the morphometric aspect, the total length, the length of the lorica, the width of the lorica and the anterior width were measured. The result showed the morphometric of rotiferB. rotundiformisfed with microalgae Prochloronsp. at 40 ppt salinity was smaller than that of the rotifer fed with N. oculata. Based on that finding it can be concluded that B. rotundiformis fed with Prochloronsp. at a salinity of 40 ppt has the potential to be developed as feed for fish larvae. Further investigations on how to accelerate the cultivation of microalgae Prochloronsp. as feeding for B. rotundiformisare needed.RotiferBrachionus rotundiformismerupakan golongan zooplankton yang digunakan sebagai makanan bagi larva ikan. Zooplankton ini banyak disukai oleh larva fauna laut, karena ukurannya kecil yang cocok dengan berbagai bukaan mulut larva. Penelitian ini bertujuan untuk mengetahui variasi morfometri rotifer B. rotundiformis, jika dikultur pada salinitas yang tinggi (40 ppt) dengan pemberian pakan berbeda. Penggunaan salinitas 40 ppt diharapkan bisa memberikan ukuran morfometrik yang bervariasi, karena rotifer jenis ini memiliki sifat polimorfisme. Alga mikro yang digunakan sebagai pakan adalah Prochloronsp. Dan Nanochloropsis oculata.Alga mikro tersebut dikultur dalam media Hirata. Pada tahap awal, B. rotundiformisdikultur pada suhu optimum (28 ºC) dengan salinitas 20 ppt; kemudian, dikultur pada salinitas 40 ppt. Adaptasi salinitas dilakukan dengan menaikkan salinitas medium sebanyak 2 ppt setiap dua hari dalam tabung reaksi berukuran 10 ml, yang berisi 10 individu. Setelah diadaptasikan, rotifer dipindahkan ke wadah berukuran 1000 ml dengan kepadatan sebanyak 50 individu dan dikultur pada salinitas 40 ppt. Aspek morfometri berupa panjang total, panjang lorica, lebar lorica, dan lebar anterior diukur. Hasil penelitian menunjukkan, bahwa panjang total rotifer B. rotundiformis, yang diberi pakan Prochloronsp. berukuran lebih kecil dibandingkan dengan rotifer yang diberi pakan N. oculata. Berdasarkan hasil penelitian dapat disimpulkan, bahwa B. rotundiformisyang diberi pakan Prochloronsp. pada salinitas 40 ppt memiliki potensi untuk dikembangkan sebagai bahan pakan bagi larva ikan. Penelitian lebih lanjut tentang cara mempercepat budidaya microalgae Prochloronsp. sebagai makan untuk B. rotundiformis diperlukan.
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Tusifujiang, Yelike, Xueni Zhang, and Lu Gong. "The relative contribution of intraspecific variation and species turnover to the community-level foliar stoichiometric characteristics in different soil moisture and salinity habitats." PLOS ONE 16, no. 2 (February 17, 2021): e0246672. http://dx.doi.org/10.1371/journal.pone.0246672.
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BackgroundTrait-based approaches have been used to demonstrate the responses of plant functional traits to environmental change may manifest both among- and/or within-species. However, how community-level foliar stoichiometric characteristic variations respond to aridity and salinity is still not well-known.MethodsWe calculated community weighted means (CWMs) and non-weighted means (CMs) of foliar C, N, and P concentrations (and their ratios) in a dryland plant community respond to high (HSW) and low soil moisture and salinity (LSW). Based on a sum of squares decomposition method, we determined the relative contributions of intraspecific variation and species turnover in both HSW and LSW habitats.ResultsThe CWMs of foliar C, C:N and C:P, and CM of N in the HSW habitat were significantly greater than those in the LSW habitat. The trait variations in two habitats were mainly driven by intraspecific variation, and its contribution to trait variation mostly declined with the decrease of soil moisture and salinity. The CWMs of foliar C-related stoichiometric characteristics were mainly dominated by species turnover in both habitats. Moreover, the contribution of species turnover to C and C:P variations showed an increasing trend in the LSW habitat. For CWMs, negative covariations between intraspecific variation and turnover occurred in HSW and positive covariations (except N:P) occurred in LSW; however, CMs were generally positively correlated in both habitats.ConclusionsThe intraspecific variation declined as drought stress intensified, which indicates that the adaptability of desert plants declined when the stress changed from salinity to aridity. The total variation of C-related traits in both habitats were mainly dominated by species turnover. These findings highlight the importance of intraspecific variation in driving desert plant response of community functional composition to salt stress, and the joint role of intraspecific variation and species turnover in resisting drought stress.
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Chevalier, C., M. Pagano, D. Corbin, and R. Arfi. "The salinity responses of tropical estuaries to changes in freshwater discharge, tidal mixing and geomorphology: case study of the man-affected Senegal River Estuary (West Africa)." Marine and Freshwater Research 65, no. 11 (2014): 987. http://dx.doi.org/10.1071/mf13169.
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Salinity in estuaries is influenced by a variety of processes including tidal advection and diffusion and river discharge. The effect of hydrodynamic features on salinity was studied in the Senegal River Estuary (SRE). This estuary is of strategic importance for large populations, but it has been greatly affected by human action (regulation of the freshwater inflow, change in the location of the river mouth ...), which has caused major changes in salinity and ecological functioning. To analyse the impacts of these changes and to determine the spatial and temporal variations in salinity in the SRE, we used a combination of three-dimensional modelling and field measurements. The overall salinity depends on freshwater inflow and tidal fluctuations. Salinity variation is mainly driven by ebb and flood near the mouth and by fortnightly cycles upstream. The enlargement of the mouth increases salinity, whereas its shifting location changes the location of the salinity front and creates a slack water zone downstream. Connection and disconnection of the tributaries also affects the salinity. The present study explains how the recent modifications have increased spatial variation and reduced seasonal differences of salinity and provides a tool for managing the water in the estuary.
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Katsura, Shota, Eitarou Oka, Bo Qiu, and Niklas Schneider. "Formation and Subduction of North Pacific Tropical Water and Their Interannual Variability." Journal of Physical Oceanography 43, no. 11 (November 1, 2013): 2400–2415. http://dx.doi.org/10.1175/jpo-d-13-031.1.
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Abstract Formation and subduction of the North Pacific Tropical Water (NPTW), its interannual variability, and its associated mechanisms were investigated by using gridded Argo-profiling float data and various surface flux data in 2003–11. The NPTW has two formation sites in the center of the North Pacific subtropical gyre, corresponding to two regional sea surface salinity maxima. Mixed layer salinity variations in these two NPTW formation sites were found to be significantly different. While seasonal variation was prominent in the eastern formation site, interannual variation was dominant in the western site. The mixed layer salinity variation in the eastern site was controlled mainly by evaporation, precipitation, and entrainment of fresher water below the mixed layer and was closely related to the seasonal variation of the mixed layer depth. In the western site, the effect of entrainment is small due to a small vertical difference in salinity across the mixed layer base, and excess evaporation over precipitation that tended to be balanced by eddy diffusion, whose strength varied interannually in association with the Pacific decadal oscillation. After subduction, denser NPTW that formed in the eastern site dissipated quickly, while the lighter one that formed in the western site was advected westward as far as the Philippine Sea, transmitting the interannual variation of salinity away from its formation region.
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Robins, Joseph G., B. Shaun Bushman, Blair L. Waldron, and Paul G. Johnson. "Variation within Poa Germplasm for Salinity Tolerance." HortScience 44, no. 6 (October 2009): 1517–21. http://dx.doi.org/10.21273/hortsci.44.6.1517.
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As competition for water resources in areas of western North America intensify as a result of increasing human populations, the sustainability of turfgrass irrigation with limited water resources is questionable. A potential part of the solution is the use of recycled wastewater for landscape irrigation. However, as a result of high levels of salt, successful irrigation with recycled wastewater will likely need to be coupled with selection for increased salinity tolerance in turfgrass species. Additionally, salinity-tolerant turfgrass will allow production on soils with inherently high salt levels. The study described here characterized the relative salinity tolerance of 93 accessions of Poa germplasm from the USDA National Plant Germplasm System (NPGS). Control cultivars of tall fescue [Lolium arundinaceum (Schreb.) S.J. Darbyshire], perennial ryegrass (Lolium perenne L.), and kentucky bluegrass (Poa pratensis L.) were also evaluated for comparison. Kentucky bluegrass accessions exhibited a wide range of LD50 (salinity dosage necessary to kill 50% of plants) values from 811 ECdays (PI 369296 from Russia) to 1922 ECdays (PI 371768 from the United States). Five kentucky bluegrass accessions exhibited salinity tolerance equal to or better than that of the tall fescue (LD50 = 1815 ECdays) and perennial ryegrass (LD50 = 1754 ECdays) checks. Thus, there is sufficient variation within this species to develop bluegrass with substantially higher salinity tolerance.
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Nguyen, Trang Cong, Hoa Van Au, Giang Trung Tran, Phuong Thanh Nguyen, and Ut Ngoc Vu. "Phytoplankton community composition variation under natural and prolonged saline intrusion simulations." International Journal of Limnology 58 (2022): 1. http://dx.doi.org/10.1051/limn/2022001.
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This study assessed phytoplankton community composition variation under two discrete salinity intrusion rate experiments. Experiment 1 simulated salinization under short-term, natural tidally induced rates of salinity change typical of the Mekong Delta, Vietnam (0–30‰ in 6 h), while Experiment 2 simulated salinization under a longer, more gradual rate of salinity change (0–30‰ at 5‰ increase per week). Phytoplankton community composition was, overall, more abundant following prolonged salinity change (Experiment 2) than rapid, tidally-induced salinity change (Experiment 1). Under both experimental conditions phytoplankton species number and density varied with changes in salinity, indicating a strong effect of salinity regardless of its rate of change. At the end of the salinity acclimation, Cyanobacteria, Chlorophyta, Euglenophyta and Bacillariophyta were all most abundant at a salinity of 5‰ after a short-term tidally simulated change in salinity, but with a longer, more gradual change in salinity, the abundance of different groups varied with salinity; With a longer, more gradual change in salinity, Chlorophyta was most abundant at 5–10‰ salinity, while Cyanobacteria, Euglenophyta and Bacillariophyta were all most abundant at a salinity of 5‰. The species composition in treatments of less than 10‰ had high similarity with the freshwater environment while treatments of 30‰ (Experiment 1) and 25‰ (Experiment 2) had high similarity with the natural seawater environment. This study demonstrates the utility of mesocosm experiments for understanding phytoplankton community composition variation in natural aquatic ecosystems under rapid and prolonged saline intrusion rates and predicting associated impacts on food webs in natural water bodies and aquaculture systems.
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FUKUOKA, Shoji, Ayako YAMAMOYO, Seiji OKAMURA, and Isamu MIZOYAMA. "ESTIMATION OF SALINITY FLUX AND VARIATION OF SALINITY IN LAKE SHINJI." PROCEEDINGS OF HYDRAULIC ENGINEERING 49 (2005): 1249–54. http://dx.doi.org/10.2208/prohe.49.1249.
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Marcum, Kenneth B., Nicholas P. Yensen, and John E. Leake. "Genotypic variation in salinity tolerance of Distichlis spicata turf ecotypes." Australian Journal of Experimental Agriculture 47, no. 12 (2007): 1506. http://dx.doi.org/10.1071/ea07164.
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Water quantity and quality issues are accelerating the search for alternative xeriphytic and halophytic turf species. Growth and physiological responses to salinity of eight Distichlis spicata (L.) Greene genotypes were observed to elucidate salinity tolerance mechanisms operating in the species. Accession 1043 was superior in salinity tolerance to other genotypes, as indicated by percentage canopy green leaf area, relative (to control) shoot growth, relative root growth, and rooting depth, when exposed to increasing salinity up to 1.0 mol/L NaCl. Salinity tolerance was associated with complete, though minimal, shoot osmotic adjustment, maintenance of low shoot saline ion levels, and high shoot K+/Na+ ratios, all of which were facilitated by high leaf salt gland ion excretion rates.
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Rabbani, Davarkhah, MohammadHadi Fattahi, Nima Mazroii, and Rouhullah Dehghani. "Salinity variation in kashan plain groundwater resources." International Archives of Health Sciences 5, no. 3 (2018): 68. http://dx.doi.org/10.4103/iahs.iahs_6_18.
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FUKUOKA, Shoji, Tomomi MATSUSHITA, Shin MIURA, Takeshi KUROKAWA, Shoji FUNABASHI, and Mikio NAKAMURA. "ON SALINITY VARIATION IN CONNECTED BRACKISH LAKE." PROCEEDINGS OF HYDRAULIC ENGINEERING 46 (2002): 899–904. http://dx.doi.org/10.2208/prohe.46.899.
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Rajabi Dehnavi, Ahmad, Morteza Zahedi, Agnieszka Ludwiczak, Stefany Cardenas Perez, and Agnieszka Piernik. "Effect of Salinity on Seed Germination and Seedling Development of Sorghum (Sorghum bicolor (L.) Moench) Genotypes." Agronomy 10, no. 6 (June 17, 2020): 859. http://dx.doi.org/10.3390/agronomy10060859.
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Salinity is one of the most important abiotic stresses that negatively affects plant growth and development around the world. It has been reported that approximately 19.5% of all irrigated land and 2.1% of dry land is affected by salt stress, and these percentages continue to increase. Sorghum, a C4 plant, is the fifth most important cereal in the world. Numerous studies reported that there are high genetic variations in sorghum. These genetic variations can be monitored to search for the most salt-tolerant genotypes. Therefore, the aim of our study was to investigate the responses of ten sorghum genotypes to different levels of salinity. We focused on germination and seedling growth as the most critical stages of plant development. In our research we included germination percentage, germination index, mean germination time, seedling vigor index, seedlings’ shoot and root lengths, fresh and dry seedling weight, and salinity tolerance indices. For data assessment we applied two-way ANOVA, non-metric multidimensional scaling, and hierarchical agglomerative classification. Our results demonstrate that salinity was responsible for 98% of the variation in assessed parameters, whereas genotype effect accounted for only 2% of the documented variation. It can be concluded that seedling traits can be used as a valid criterion for the selection of genotypes with a better tolerance to salinity stress.
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Stickle, William B., Li-Lian Liu, and David W. Foltz. "Allozymic and physiological variation in populations of sea urchins (Strongylocentrotus spp.)." Canadian Journal of Zoology 68, no. 1 (January 1, 1990): 144–49. http://dx.doi.org/10.1139/z90-021.
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Tolerance and activity coefficients (1000/righting time (s)) were determined in different salinity treatments for Strongylocentrotus droebachiensis (O. F. Muller, 1776) from a variable-salinity habitat north of Juneau, Alaska, and for S. droebachiensis and S. pallidus (G. O. Sars, 1871) from high-salinity habitats near Friday Harbor, Washington. The 28-day LC50 values of populations of S. droebachiensis from southeastern Alaska and Washington were similar (13‰ salinity) while that of S. pallidus was 21‰ salinity. Activity coefficients of S. droebachiensis indicate functional competence from 20 to 30‰ salinity; S. pallidus remains competent only at 30‰ salinity. For allozymic analysis, sea urchins (N = 820) were collected from five locations (three in Alaska and two in Washington). Two polymorphic allozyme loci (malate dehydrogenase-2 and phosphoglucose isomerase) were examined in all populations. The difference in allele frequencies between the species was highly significant (P < 0.0001) for Mdh-2 and nominally significant (P < 0.05) for Pgi. However, the species share the same alleles at both loci, and the allele frequency variance between the two species is low. Genotypic variation exists between the two species of sea urchins but not among populations of S. droebachiensis. Strongylocentrotus droebachiensis from Alaska and Washington are equally euryhaline with respect to tolerance but the brackish-water population is more active at 15‰ salinity.
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Robinson, Beren W. "Evolution of growth by genetic accommodation in Icelandic freshwater stickleback." Proceedings of the Royal Society B: Biological Sciences 280, no. 1772 (December 7, 2013): 20132197. http://dx.doi.org/10.1098/rspb.2013.2197.
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Classical Darwinian adaptation to a change in environment can ensue when selection favours beneficial genetic variation. How plastic trait responses to new conditions affect this process depends on how plasticity reveals to selection the influence of genotype on phenotype. Genetic accommodation theory predicts that evolutionary rate may sharply increase when a new environment induces plastic responses and selects on sufficient genetic variation in those responses to produce an immediate evolutionary response, but natural examples are rare. In Iceland, marine threespine stickleback that have colonized freshwater habitats have evolved more rapid individual growth. Heritable variation in growth is greater for marine full-siblings reared at low versus high salinity, and genetic variation exists in plastic growth responses to low salinity. In fish from recently founded freshwater populations reared at low salinity, the plastic response was strongly correlated with growth. Plasticity and growth were not correlated in full-siblings reared at high salinity nor in marine fish at either salinity. In well-adapted lake populations, rapid growth evolved jointly with stronger plastic responses to low salinity and the persistence of strong plastic responses indicates that growth is not genetically assimilated. Thus, beneficial plastic growth responses to low salinity have both guided and evolved along with rapid growth as stickleback adapted to freshwater.
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Lin, Zhongyuan, Guang Zhang, Huazhi Zou, and Wenping Gong. "Salt intrusion dynamics in a well-mixed sub-estuary connected to a partially to well-mixed main estuary." Ocean Science 20, no. 1 (February 19, 2024): 181–99. http://dx.doi.org/10.5194/os-20-181-2024.
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Abstract. Salt intrusion in estuaries has been exacerbated by climate change and human activities. Previous studies have primarily focused on salt intrusion in the mainstem of estuaries, whereas those in sub-estuaries (those that branch off their main estuaries) have received less attention. During an extended La Niña event from 2021 to 2022, a sub-estuary (the East River estuary) alongside the Pearl River estuary, China, experienced severe salt intrusions, posing a threat to the freshwater supply in the surrounding area. Observations revealed that maximum salinities in the main estuary typically preceded spring tides, exhibiting significant asymmetry in salinity rise and fall over a fortnightly timescale. In contrast, in the upstream region of the sub-estuary, the variation in salinity was in phase with that of the tidal range, and the rise and fall of the salinity were more symmetrical. Inspired by these observations, we employed idealized numerical models and analytical solutions to investigate the underlying physics behind these behaviors. It was discovered that under normal dry conditions (with a river discharge of 1500 m3 s−1 at the head of the main estuary), the river–tide interaction and change in horizontal dispersion accounted for the in-phase relationship between the salinity and tidal range in the upstream region of the sub-estuary. Under extremely dry conditions (i.e., a river discharge of 500 m3 s−1 at the head of the main estuary), salinity variations were in phase with those of the tidal range in the middle as well as the upstream region of the sub-estuary. The variation in salinity in the main estuary along with those in salt dispersion and freshwater influx inside the sub-estuary collectively influenced salinity variation in the well-mixed sub-estuary. These findings have important implications for water resource management and salt intrusion prevention in the catchment area.
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Xie, Kang, Jing Song, Si Qing Xia, Li Ping Qiu, Jia Bin Wang, and Shou Bin Zhang. "Variation of Membrane Fouling Characteristics at Salinity Wastewater in an Intermittently Aerated Membrane Bioreactor." Advanced Materials Research 1092-1093 (March 2015): 1029–32. http://dx.doi.org/10.4028/www.scientific.net/amr.1092-1093.1029.
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In this study, the variation of Zeta potentials and distribution of molecular weight in Extracellular Polymeric Substances (EPS) and soluble microbial products (SMP) were investigated. It is indicated that the salinity is effect on Zeta potentials significantly. When the salinity increased from 0 g/L to 35 g/L, the Zeta potentials decreased gradually. The average molecular weight is mainly over 30 KDa in EPS and SMP at 0 g/L salinity, and is mainly below 10 KDa at 10 g/L and 35 g/L salinity. This result is evident that the variation of molecular weight is contributed to high salinity.
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Chengfu, Yuan. "Analysis on the groundwater salt dynamic in a monitoring area in Hetao Irrigation District of Inner Mongolia." E3S Web of Conferences 198 (2020): 02007. http://dx.doi.org/10.1051/e3sconf/202019802007.
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In order to explore the rule of groundwater salt dynamic in Hetao Irrigation District, a typical monitoring area was selected as the research area in Yongji Irrigation Area of Hetao Irrigation District. The groundwater level and groundwater salinity were analyzed during the year and inter-annual variation in 2008-2013. The groundwater level showed an obvious seasonal change trend during the year variation. The groundwater level was at the peak value after spring irrigation and autumn irrigation. The groundwater level was at the low value before melting and autumn irrigation. The groundwater level had an obvious periodicity during the inter-annual variation. The groundwater level could keep a relatively stable for many years. The groundwater salinity showed an obvious seasonal change trend during the year variation. The groundwater salinity was greatly affected by irrigation and had a decreased trend after irrigation. The groundwater salinity had an obvious periodicity during the inter-annual variation and could keep a relatively stable for many years in cultivated land. The groundwater salinity had an increased trend during the inter-annual variation in wasteland. The wasteland was the drainage area for cultivated land. The wasteland had an obvious role in adjusting salt dynamic balance in Hetao Irrigation District.
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McKinney, Richard, Alana Hanson, Roxanne Johnson, and Michael Charpentier. "Seasonal variation in apparent conductivity and soil salinity at two Narragansett Bay, RI salt marshes." PeerJ 7 (November 27, 2019): e8074. http://dx.doi.org/10.7717/peerj.8074.
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Measurement of the apparent conductivity of salt marsh sediments using electromagnetic induction (EMI) is a rapid alternative to traditional methods of salinity determination that can be used to map soil salinity across a marsh surface. Soil salinity measures can provide information about marsh processes, since salinity is important in determining the structure and function of tidally influenced marsh communities. While EMI has been shown to accurately reflect salinity to a specified depth, more information is needed on the potential for spatial and temporal variability in apparent conductivity measures that may impact the interpretation of salinity data. In this study we mapped soil salinity at two salt marshes in the Narragansett Bay, RI estuary monthly over the course of several years to examine spatial and temporal trends in marsh salinity. Mean monthly calculated salinity was 25.8 ± 5.5 ppt at Narrow River marsh (NAR), located near the mouth of the Bay, and 17.7 ± 5.3 ppt at Passeonkquis marsh (PAS) located in the upper Bay. Salinity varied seasonally with both marshes, showing the lowest values (16.3 and 8.3 ppt, respectively) in April and highest values (35.4 and 26.2 ppt, respectively) in August. Contour plots of calculated salinities showed that while the mean whole-marsh calculated salinity at both sites changed over time, within-marsh patterns of higher versus lower salinity were maintained at NAR but changed over time at PAS. Calculated salinity was significantly negatively correlated with elevation at NAR during a sub-set of 12 sample events, but not at PAS. Best-supported linear regression models for both sites included one-month and 6-month cumulative rainfall, and tide state as potential factors driving observed changes in calculated salinity. Mapping apparent conductivity of salt marsh sediments may be useful both identifying within-marsh micro-habitats, and documenting marsh-wide changes in salinity over time.
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Li, Guancheng, Lijing Cheng, and Xutao Wang. "Evaluation of the CAS-ESM2-0 Performance in Simulating the Global Ocean Salinity Change." Atmosphere 14, no. 1 (January 3, 2023): 107. http://dx.doi.org/10.3390/atmos14010107.
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The second version of the Chinese Academy of Sciences Earth System Model, CAS-ESM2-0, is a newcomer that contributes to Coupled Model Intercomparison Project simulations in the community. We evaluated the model’s performance in simulating the salinity for climatology, seasonal cycles, long-term trends, and time series of climatic metrics by comparing it with the ensemble mean of available gridded observations. The results showed that CAS-ESM2-0 could reproduce large-scale patterns of ocean salinity climatology and seasonal variations, despite the fresh biases in the low- and mid-latitudes for climatology, stronger seasonal variation of sea surface salinity within 20° S–20° N, and large uncertainty with the zonal-band structure for 0–1000 m averaged salinity. For long-term changes, the model revealed increased contrast between the salinity of the Atlantic and Pacific basins. However, regional differences in locations and strengths for salinity pattern amplification suggest substantial uncertainty when simulating regional multidecadal salinity changes. The simulated variations in climate metrics for salinity pattern amplification are consistent with the observations and will continue to intensify until the end of this century. Our assessment provides new features of the CAS-ESM2-0 model and supports further studies on model development.
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Radtke, Hagen, Sandra-Esther Brunnabend, Ulf Gräwe, and H. E. Markus Meier. "Investigating interdecadal salinity changes in the Baltic Sea in a 1850–2008 hindcast simulation." Climate of the Past 16, no. 4 (August 27, 2020): 1617–42. http://dx.doi.org/10.5194/cp-16-1617-2020.
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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.
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Chen, Zhaomin, Qingqiang Ren, Chunlong Liu, and Weiwei Xian. "Seasonal and Spatial Variations in Fish Assemblage in the Yangtze Estuary and Adjacent Waters and Their Relationship with Environmental Factors." Journal of Marine Science and Engineering 10, no. 11 (November 7, 2022): 1679. http://dx.doi.org/10.3390/jmse10111679.
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In this work, we identified the seasonal and spatial variations in fish assemblages and their relation to environmental variables in the Yangtze Estuary and adjacent waters. A total of 61 fish species in 32 families were identified over four seasons; of these, 12 species were dominant and Harpadon nehereus was the most dominant species. Fish varied in abundance, biomass, and species composition in different seasons; both biomass and abundance were highest in autumn and lowest in spring. Fish can be spatially divided into high-salinity assemblages and low-salinity assemblages. The spatial variation in fish assemblages was caused by the selectivity and adaptability of species for the environmental conditions of the estuary and the seasonal variation in fish assemblage structure likely resulted from migrations of dominant taxa associated with fish spawning and foraging behavior as well as the environment. The results of CCA analysis showed that temperature, depth, salinity, dissolved oxygen, and chlorophyll were the major factors affecting the fish assemblage differences throughout the seasons. Of these, temperature drove the seasonal variation in assemblage structure, while salinity significantly affected the spatial distribution of assemblages. This paper revealed the relationship between the seasonal and spatial distribution patterns of the fish assemblage and environmental factors and the results could provide a scientific basis for the management and sustainable utilization of fishery resources in the Yangtze Estuary and adjacent waters.
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Ma, Hua, Li-Juan Cui, Wei Li, Yu Ning, Yin-Ru Lei, Xu Pan, Yi-Fei Wang, and Man-Yin Zhang. "Effect of daily salinity fluctuation on the intraspecific interactions of a euhalophyte (Suaeda salsa) along a salinity gradient." Journal of Plant Ecology 15, no. 1 (January 11, 2022): 208–21. http://dx.doi.org/10.1093/jpe/rtac002.
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Abstract Heterogeneity of soil salinity is a prominent environmental characteristic in the intertidal zone of estuaries, affecting the plant growth and the shift of biotic interactions in the salt marsh. This study aims to examine the interactive effects of a salinity gradient and salinity fluctuations on intraspecific interactions of a euhalophyte. We assessed the impact of daily fluctuating salinity on the outcome of intraspecific interactions by cultivating seeds of Suaeda salsa (Chenopodiaceae) in river sand. The experiment was conducted in a greenhouse with three treatments: daily salinity fluctuations (static and fluctuating salinity), a salinity gradient (200 and 400 mmol L−1) and three planting densities (1, 2 and 4 plants/pot). First, height and biomass of plants were measured at both the start and end of the experiment. Then, the growth indexes and log response ratio of S. salsa were analyzed. The outcome of intraspecific interactions of S. salsa shifted from competition in low salinity to facilitation in high salinity, and high conspecific density strengthened the competition and facilitation intensities. Daily salinity fluctuation did not significantly affect the plant growth and the outcome of intraspecific interactions, but did have a significant influence on belowground biomass. Our results suggest that the stress-gradient hypothesis may apply to predicting the variation of the intraspecific relationship of a salt-tolerant species along a salinity gradient, and the magnitude of this variation is density dependent. These findings help us understand how individuals and populations of a euhalophyte species respond to the natural variation or human modification of salinity conditions.
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Shafeeqa, T., V. Ravichandran, A. Senthil, L. Arul, and S. Radhamani. "Assessment of seedling traits of rice landraces under different saline conditions." Journal of Applied and Natural Science 14, no. 4 (December 19, 2022): 1252–63. http://dx.doi.org/10.31018/jans.v14i4.3887.
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Salinity is one of the major abiotic stresses affecting rice growth and yield worldwide. In rice, the most critical stages which affect salinity at a greater level are germination, vegetative and reproductive stages.It is very important to know the genotypic variation among landraces under saline conditions at the seed germination stage to reduce the harmful effect of salinity. The present study conducted on Petri plate was mainly for assessing germination, relative water content and seedling parameters of eleven rice landraces with check landrace Pokali under three different salt concentrations (75mM, 125mM and 150mM). Two-way ANOVA gave the variations among the genotypes, treatments and their interactions. The present study showed that Mundan, Odiyan, Muttadan, Kallimadiyan and Vellimuthu had less percentage reduction in growth parameters at the germination stage. Odiyan and Mundan showed less percentage reduction in fresh weight (36.09%) and shoot length (25.61%) respectively, in relative water content (10.70% and 16.07%, respectively) at higher concentrations of salinity (150mM) compared to control. Pokali, Chembakam and Odiyan showed good germination parameters under three different saline treatments compared to other genotypes. Biplot analysis showed 65.4% variation between the treatments, whereas the variation between the genotypes was around 13.3%. Screening of landraces for salinity tolerance at the seed germination stage is the most reliable method to identify the salt tolerant line at the early seedling stage. The present study can be used for further screening programme at the vegetative stage for the identification of potential salt tolerant lines to improve breeding and gene introgression studies.
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Griffiths, Joanna S., Kevin M. Johnson, Kyle A. Sirovy, Mark S. Yeats, Francis T. C. Pan, Jerome F. La Peyre, and Morgan W. Kelly. "Transgenerational plasticity and the capacity to adapt to low salinity in the eastern oyster, Crassostrea virginica." Proceedings of the Royal Society B: Biological Sciences 288, no. 1951 (May 19, 2021): 20203118. http://dx.doi.org/10.1098/rspb.2020.3118.
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Salinity conditions in oyster breeding grounds in the Gulf of Mexico are expected to drastically change due to increased precipitation from climate change and anthropogenic changes to local hydrology. We determined the capacity of the eastern oyster, Crassostrea virginica , to adapt via standing genetic variation or acclimate through transgenerational plasticity (TGP). We outplanted oysters to either a low- or medium-salinity site in Louisiana for 2 years. We then crossed adult parents using a North Carolina II breeding design, and measured body size and survival of larvae 5 dpf raised under low or ambient salinity. We found that TGP is unlikely to significantly contribute to low-salinity tolerance since we did not observe increased growth or survival in offspring reared in low salinity when their parents were also acclimated at a low-salinity site. However, we detected genetic variation for body size, with an estimated heritability of 0.68 ± 0.25 (95% CI). This suggests there is ample genetic variation for this trait to evolve, and that evolutionary adaptation is a possible mechanism through which oysters will persist with future declines in salinity. The results of this experiment provide valuable insights into successfully breeding low-salinity tolerance in this commercially important species.
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Lobato, Cléo M. C., Bruno E. Soares, and Luciano F. A. Montag. "Temporal and spatial variation in the trophic ecology of the banded puffer fish Colomesus psittacus (Tetraodontiformes: Tetraodontidae) in the Amazon coastal zone." Marine and Freshwater Research 69, no. 11 (2018): 1724. http://dx.doi.org/10.1071/mf17328.
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Tidal cycles and spatial and seasonal variations in salinity have a marked effect on foraging and feeding patterns of fishes in tropical estuaries. We quantified spatiotemporal variations in the diet of one of the most abundant fish of the Amazon estuary, the Tetraodontidae banded puffer fish Colomesus psittacus, in relation to macrotidal cycles and salinity changes. Monthly samplings were performed at three sites in the Amazon coastal zone in tidal creeks with different salinity levels (Mosqueiro Island, Maiandeua Island and Ajuruteua Beach). Feeding intensity was higher during the spring tide at both Maiandeua and Ajuruteua islands, which can be accounted for by the wider foraging area for the species and higher prey availability. The diet was composed primarily of the cirriped Amphibalanus, Brachyura crustaceans and the mollusc Littoraria angulifera Lamarck, 1822. Diet composition varied spatially and temporally by periods of the year, sampling site, tides and the size of individuals. However, this variation was more pronounced in the area with high and relatively stable salinity (Ajuruteua), in contrast with the polyhaline environment at Maiandeua Island, where seasonal fluctuations in salinity result in the mixing of freshwater, estuarine and marine invertebrates.
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Shen, Hui, Li Li, Jianlong Li, Zhiguo He, and Yuezhang Xia. "The Seasonal Variation of the Anomalously High Salinity at Subsurface Salinity Maximum in Northern South China Sea from Argo Data." Journal of Marine Science and Engineering 9, no. 2 (February 20, 2021): 227. http://dx.doi.org/10.3390/jmse9020227.
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The large variations in salinity at the salinity maximum in the northern South China Sea (NSCS), as an indicator for the changes in the Kuroshio intrusion (KI), play an important role in the hydrological cycle. The high salinity here is more than 34.65 at the salinity maximum and is intriguing. In the past, the salinity was difficult to trace in the entire NSCS over long periods due to a lack of high-quality observations. However, due to the availability of accumulated temperature and salinity (T-S) profiles from the Argo program, it is now possible to capture subsurface-maximum data on a large spatiotemporal scale. In this study, the salinity maximum distributed in the subsurface of 80 to 200 m at a density of 23.0–25.5 σθ was extracted from decades of Argo data (on the different pressure surfaces, 2006–2019). We then further studied the spatial distribution and seasonal variation of the salinity maximum and its anomalously high salinity. The results suggest that a high salinity (salinity > 34.65, most of which is located at the shallow depths < 100 m) at the subsurface salinity-maximum layer often occurs in the NSCS, especially near the Luzon Strait, which accounts for about 23% of the total salinity maximum. In winter, the anomalously high salinity at the shallow subsurface salinity maximum can extend to the south of 17° N, while it rarely reaches 18° N and tends to locate at deeper waters in summer. The T-S values of the anomalously high-salinity water are between the mean T-S values in the NSCS and north Pacific subsurface water, implying that the outer sea water gradually mixes with the South China Sea water after passing through the Luzon Strait. Finally, our results show that the factors play an important role in the appearance and distribution of the anomalously high salinity at the subsurface salinity maximum, including the strength of the Kuroshio intrusion, the local wind stress curl and the anticyclonic eddy shedding from the loop current.
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Sun, Jian, Kun Yang, Hong Li Wang, and Wei Li. "Numerical Assessment of Environmental Impact of Brine Discharge from a Desalination Plant on Coastal Water." Applied Mechanics and Materials 188 (June 2012): 319–23. http://dx.doi.org/10.4028/www.scientific.net/amm.188.319.
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In North China, water shortage imposes constraint on economic and social development. Seawater desalination provides an effective approach to relieve this disadvantage, while this industry also accompanies with adverse environmental effects. To study the environmental impact of brine discharge from a desalination plant at the planning stage on the west coastal line of the Bohai Bay, the salinity distributions are predicted by using numerical simulation. Monthly variations of salinity distributions are given and the impacted areas are calculated. The results show that the mean area with salinity rising of 1 and 2 are about 40 and 10 square kilometers, respectively. The maximum impact areas are about 80 and 35 square kilometers respectively, which will take place in spring. The salinity variation at the inlet is predicted, which is fluctuated with the tidal oscillations, and the maximum salinity level is below 35 in this position.
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Covernton, GA, and CDG Harley. "Multi-scale variation in salinity: a driver of population size and structure in the muricid gastropod Nucella lamellosa." Marine Ecology Progress Series 643 (June 11, 2020): 1–19. http://dx.doi.org/10.3354/meps13355.
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The abiotic environment varies continuously at a variety of temporal scales. While this variation is known to be ecologically important, multiple scales of variability are rarely explicitly considered in ecological studies. Here, we combine field observations and laboratory experiments to determine the individual and population level effects of short-term (tidal) and longer-term (seasonal and interannual) salinity variation on the dogwhelk Nucella lamellosa in the Strait of Georgia, British Columbia, Canada. The Fraser River heavily influences surface salinity in the Strait of Georgia, which varies with season, depth, and distance to the river mouth. At low salinity sites, N. lamellosa population size decreased following high outflow years, with fewer juveniles present, as opposed to high salinity sites, which had higher population densities in all years. Sustained salinity exposure in the laboratory caused developmental delay of encapsulated embryos and complete mortality at 9 and 12 psu. Juvenile dogwhelks (<30 mm shell length) and those from a high salinity site experienced higher mortality in low salinity conditions than larger individuals and those from a low salinity site. The inclusion of a 3 h daily exposure to 20 psu, simulating high tides in a stratified water column, enabled N. lamellosa to survive otherwise low salinity conditions for considerably longer. Overall, our results suggest that seasonal and interannual variation in salinity have a profound influence on N. lamellosa populations and that shorter-scale fluctuations can moderate these seasonal and interannual effects. It is likely that similar multi-scale environmental effects will determine survival and population dynamics in many species.
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Salman, Nader. "Impact of Salinity Changes in Shatt Al-Arab Estuary on Biodiversity of Marine Mammals of the Arabian Gulf: A Review." Biological and Applied Environmental Research 5, no. 2 (July 7, 2021): 260–72. http://dx.doi.org/10.51304/baer.2021.5.2.260.
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Salinity changes in the Shatt Al-Arab Estuary and North-West Arabian Gulf were monitored and reviewed in terms of the shortage of freshwater inflows to the Shatt Al-Arab Estuary. Data from previous and current surveys on marine mammals in the area have also been checked and compared to study the biodiversity under newly-developed circumstances. The Eco-physiological investigation was performed to assess the salinity tolerance limits of whales, dolphins and dugong. One-third of the world’s 81 species of whales and dolphins, collectively called cetaceans, are thought to occur off the shores in the area. The new checklist is prepared according to recent surveys in the neighbouring Arab Gulf countries and the known checklist of mammals in Iraqi waters. Spatial variation of the marine mammals of the southern part was governed by the occurrence of feeding habitats rather than a direct response to salinity variations. Alteration of seaweed’s habitats in response to water pollution is reported to have a direct effect on the biodiversity of mammals in the gulf. The results of this review were discussed in terms of salinity tolerance, hazardous ecological factors and spatial variation. No obvious effect of salinity changes imposed by the shortage of freshwater inflow on the distribution or loss of marine mammals neither on their habitat in the Arabian Gulf.
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Kuroda, Naoki, Katsuhide Yokoyama, and Tadaharu Ishikawa. "Development of a Practical Model for Predicting Soil Salinity in a Salt Marsh in the Arakawa River Estuary." Water 13, no. 15 (July 28, 2021): 2054. http://dx.doi.org/10.3390/w13152054.
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Our group has studied the spatiotemporal variation of soil and water salinity in an artificial salt marsh along the Arakawa River estuary and developed a practical model for predicting soil salinity. The salinity of the salt marsh and the water level of a nearby channel were measured once a month for 13 consecutive months. The vertical profile of the soil salinity in the salt marsh was measured once monthly over the same period. A numerical flow simulation adopting the shallow water model faithfully reproduced the salinity variation in the salt marsh. Further, we developed a soil salinity model to estimate the soil salinity in a salt marsh in Arakawa River. The vertical distribution of the soil salinity in the salt marsh was uniform and changed at almost the same time. The hydraulic conductivity of the soil, moreover, was high. The uniform distribution of salinity and high hydraulic conductivity could be explained by the vertical and horizontal transport of salinity through channels burrowed in the soil by organisms. By combining the shallow water model and the soil salinity model, the soil salinity of the salt marsh was well reproduced. The above results suggest that a stable brackish ecotone can be created in an artificial salt marsh using our numerical model as a design tool.
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Ashraf, M. "Genetic Variation for Salinity Tolerance in Spring Wheat." Hereditas 120, no. 2 (May 28, 2004): 99–104. http://dx.doi.org/10.1111/j.1601-5223.1994.00099.x.
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Hasegawa, Takuya, Kentaro Ando, Iwao Ueki, Keisuke Mizuno, and Shigeki Hosoda. "Upper-Ocean Salinity Variability in the Tropical Pacific: Case Study for Quasi-Decadal Shift during the 2000s Using TRITON Buoys and Argo Floats." Journal of Climate 26, no. 20 (October 4, 2013): 8126–38. http://dx.doi.org/10.1175/jcli-d-12-00187.1.
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Abstract Upper-ocean salinity variation in the tropical Pacific is investigated during the 2000s, when Triangle Trans-Ocean Buoy Network (TRITON) buoys and Argo floats were deployed and more salinity data were observed than in previous periods. This study focuses on upper-ocean salinity variability during the warming period of El Niño–Southern Oscillation (ENSO)-like quasi-decadal (QD)-scale sea surface temperature anomalies over the central equatorial Pacific (January 2002–December 2005; hereafter “warm QD phase”). It is shown that strong negative salinity anomalies occur in the western tropical Pacific and the off-equatorial Pacific in the upper ocean at depths less than 80 m, showing a horseshoe-like pattern centered at the western tropical Pacific during the warm QD phase. TRITON mooring buoy data in the western equatorial Pacific show that low-salinity and high-temperature water could be transported eastward from the western equatorial Pacific to the central equatorial Pacific during the warm QD phase. Similar patterns, but with the opposite sign of salinity anomalies, appear in the cold QD phase during January 2007–December 2009 with negative sea surface temperature anomalies over the central equatorial Pacific. It is suggested that effects from zonal salinity advection and precipitation could contribute to the generation of the salinity variations in the western equatorial Pacific for QD phases during the 2000s. On the other hand, the contribution of meridional salinity advection is much less than that of zonal salinity advection. In addition, El Niño Modoki and La Niña events could affect salinity changes for warm and cold QD phases via interannual-scale zonal salinity advection variations in the western equatorial Pacific during the 2000s.
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Shapouri, M., L. Cancela da Fonseca, S. Iepure, T. Stigter, L. Ribeiro, and A. Silva. "The variation of stygofauna along a gradient of salinization in a coastal aquifer." Hydrology Research 47, no. 1 (April 28, 2015): 89–103. http://dx.doi.org/10.2166/nh.2015.153.
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We examined the variation of stygofauna composition collected in wells, along a gradient in groundwater salinity/conductivity in a coastal aquifer from southern Portugal. The studied coastal aquifer is considered vulnerable to salinization due to seawater intrusion, caused by overexploitation of the aquifer. Knowing the response of the stygofauna species to present levels of groundwater salinity makes it possible to understand and measure the effects of saltwater intrusion on stygofauna, rendering them potential bioindicators of this environmental pressure. Biotic and abiotic sampling was conducted in six shallow wells located in the fresh–saltwater interface of the Arade estuary along the salinity gradient established in the groundwater from the estuary to inland locations (microSiemens/cm). Groundwater salinity was highly correlated with taxa distribution. The stygobites Eucyclops hadjebensis and Acanthocyclops sensitivus, the cosmopolitan Megacyclops viridis and Cypria ophtalmica were particularly associated with low-salinity conditions, whereas Eucyclops graeteri, Megacyclops brachypus and Daphnia pulicaria were related to high-salinity waters. Multivariate analyses indicated that stygofauna assemblages varied significantly with location. We suggest that stygofauna composition and structure can be a useful complementing tool for monitoring seawater intrusion into coastal aquifers, where reduction or deterioration in groundwater resources is predicted.
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Shelden, Megan C., Ute Roessner, Robert E. Sharp, Mark Tester, and Antony Bacic. "Genetic variation in the root growth response of barley genotypes to salinity stress." Functional Plant Biology 40, no. 5 (2013): 516. http://dx.doi.org/10.1071/fp12290.
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We aimed to identify genetic variation in root growth in the cereal crop barley (Hordeum vulgare L.) in response to the early phase of salinity stress. Seminal root elongation was examined at various concentrations of salinity in seedlings of eight barley genotypes consisting of a landrace, wild barley and cultivars. Salinity inhibited seminal root elongation in all genotypes, with considerable variation observed between genotypes. Relative root elongation rates were 60–90% and 30–70% of the control rates at 100 and 150 mM NaCl, respectively. The screen identified the wild barley genotype CPI71284–48 as the most tolerant, maintaining root elongation and biomass in response to salinity. Root elongation was most significantly inhibited in the landrace Sahara. Root and shoot Na+ concentrations increased and K+ concentrations decreased in all genotypes in response to salinity. However, the root and shoot ion concentrations did not correlate with root elongation rates, suggesting that the Na+ and K+ concentrations were not directly influencing root growth, at least during the early phase of salt stress. The identification of genetic diversity in root growth responses to salt stress in barley provides important information for future genetic, physiological and biochemical characterisation of mechanisms of salinity tolerance.
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Aksnes, D. L. "Sverdrup critical depth and the role of water clarity in Norwegian Coastal Water." ICES Journal of Marine Science 72, no. 6 (February 25, 2015): 2041–50. http://dx.doi.org/10.1093/icesjms/fsv029.
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Abstract The critical depth concept was first recognized by Gran and Braarud (1935). During summer, in the Bay of Fundy, they observed an unexpected no bloom situation. Their interpretation was that high amounts of detritus of terrestrial origin caused too murky water and insufficient light for the tidally mixed phytoplankton. Almost 20 years later, this was elaborated by Sverdrup (1953) into a hypothesis for the initiation of the spring bloom in the North Atlantic Water (NAW) masses. Since then, variations in mixed layer depth have been a key in phytoplankton modelling. As illustrated by the study of Gran and Braarud, variation in the non-phytoplankton light attenuation coefficient is also a key to understand phytoplankton bloom conditions. Due to lack of accurate parameterizations, however, non-phytoplankton light attenuation is often assumed invariant in phytoplankton modelling. Here, I report spatial variation in a proxy for the pre-bloom light attenuation in Norwegian Coastal Water (NCW). It is shown that this variation can be partially accounted for by variations in salinity and dissolved oxygen. The light attenuation coefficient at 440 nm increased by 0.041 and 0.032 m−1 with drops in salinity and dissolved oxygen of 1PSU and 1 ml O2 l−1, respectively. Consequences for the euphotic depth, Sverdrup critical depth, and the nutricline depth are discussed. I conclude that phytoplankton modelling, particularly across coastal and oceanic waters, such as NCW and NAW, needs to account for variations in the non-phytoplankton light attenuation and that salinity might be a useful proxy for regional parameterizations.
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Eltarabily, Mohamed G., Abdulrahman Amer, Mohammad Farzamian, Fethi Bouksila, Mohamed Elkiki, and Tarek Selim. "Time-Lapse Electromagnetic Conductivity Imaging for Soil Salinity Monitoring in Salt-Affected Agricultural Regions." Land 13, no. 2 (February 11, 2024): 225. http://dx.doi.org/10.3390/land13020225.
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In this study, the temporal variation in soil salinity dynamics was monitored and analyzed using electromagnetic induction (EMI) in an agricultural area in Port Said, Egypt, which is at risk of soil salinization. To assess soil salinity, repeated soil apparent electrical conductivity (ECa) measurements were taken using an electromagnetic conductivity meter (CMD2) and inverted (using a time-lapse inversion algorithm) to generate electromagnetic conductivity images (EMCIs), representing soil electrical conductivity (σ) distribution. This process involved converting EMCI data into salinity cross-sections using a site-specific calibration equation that correlates σ with the electrical conductivity of saturated soil paste extract (ECe) for the collected soil samples. The study was performed from August 2021 to April 2023, involving six surveys during two agriculture seasons. The results demonstrated accurate prediction ability of soil salinity with an R2 value of 0.81. The soil salinity cross-sections generated on different dates observed changes in the soil salinity distribution. These changes can be attributed to shifts in irrigation water salinity resulting from canal lining, winter rainfall events, and variations in groundwater salinity. This approach is effective for evaluating agricultural management strategies in irrigated areas where it is necessary to continuously track soil salinity to avoid soil fertility degradation and a decrease in agricultural production and farmers’ income.
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Flores-Hernández, Domingo, Julia Ramos-Miranda, Luis Amado Ayala-Pérez, and Francisco Gómez Criollo. "Environmental variation vs co-occurrence of two fish families (Gerreidae and Ariidae) in Terminos Lagoon, Campeche, Mexico." JAINA Costas y Mares ante el Cambio Climático 3, no. 1 (August 6, 2021): 5–22. http://dx.doi.org/10.26359/52462.0121.
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Terminos Lagoon is recognized as an ecosystem of great diversity and productivity in the southern Gulf of Mexico. It is also the site of various anthropogenic activities in the lagoon as well as in its surroundings. In addition, in recent years this lagoon has showed variations in temperature and salinity as a result of global warming and/or watershed management. This has generated variations in the structure and function of fish communities, among other taxonomic groups. IIn this work, we analyze the changes in abundance and distribution associated with modifications in the salinity of fish species from two key families (Ariidae y Gerreidae) during the years 1980, 1998, and 2011. Salinity is analyzed in the three periods (ANOVA, Tukey (HSD); the abundance of species, environmental breadth according to salinity (Levins Index), environmental overlap (Pianka Index), and co-occurrence (C-score) are also analyzed. Statistical differences were tested using the null model. The results showed high variability in salinity, with a tendency to increase during the studied period with 24.7, 27.9, and 28.4 UPS for each year, respectively (p < 0.0001). The abundance of both families increased from 1980 to 1998 and decreased in 2011 (82% for Ariidae and 62% for Gerreidae). The C-score ranged from 1.07 in 1980 to 0.78 in 1998 and 2.71 in 2011. The observed averages were significantly lower than the simulated average (P <0.0001). In conclusion, the increase in salinity is probably one of the causes of a variation in the abundance of fish species. According to a possible more limited competition for space, fish abundance and C-score fluctuated inversely, indicating a trend towards a more generalist fish community. Keywords: Environmental breadth, environmental overlapping, co-ocurrence, and salinity gradient.
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Uddin, MS, and KMW Hossain. "Screening of wheat genotypes against salinity at early vegetative stage in pot culture." Bangladesh Journal of Botany 47, no. 3 (October 28, 2018): 381–87. http://dx.doi.org/10.3329/bjb.v47i3.38655.
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Experiment was carried out to investigate intraspecific variation for salt tolerance and to classify the wheat genotypes into different salt tolerant groups. Considerable variations among the genotypes in response to salinity were observed for shoot length under 16 dS/m NaCl salinity in the both seasons. Salt tolerant genotype was found to be less affected at high salinity and could be produced better total dry matter compared to other genotypes. Five and seven genotypes appeared as tolerance during 2008 - 09 and 2009 - 10, respectively based on relative total dry matter (RTDM). On the other hand, six and three genotypes exhibited tolerant during 2008 - 09 and 2009 - 10, respectively based on visual scoring. The distribution pattern of the genotypes into various salinity tolerant groups remained fairly constant under two methods. Three genotypes G24, G33 and G40 exhibited tolerant category. RTDM compared to the control would be very useful trait in salinity tolerant improvement programme. However, visual scoring provide guidelines for mass screening of salt tolerant genotypes.
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Jiang, Xinjun, Zhu Zhu, Jinnan Wu, Ergang Lian, Dongyan Liu, Shouye Yang, and Ruifeng Zhang. "Bacterial and Protistan Community Variation across the Changjiang Estuary to the Ocean with Multiple Environmental Gradients." Microorganisms 10, no. 5 (May 9, 2022): 991. http://dx.doi.org/10.3390/microorganisms10050991.
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Plankton microorganisms play central roles in the marine food web and global biogeochemical cycles, while their distribution and abundance are affected by environmental variables. The determinants of microbial community composition and diversity in estuaries and surrounding waters with multiple environmental gradients at a fine scale remain largely unclear. Here, we investigated bacterial and protistan community assembly in surface waters from 27 stations across the Changjiang Estuary to the ocean, with salinity ranging from 0 to 32.1, using 16S rRNA and 18S rRNA gene amplicon sequencing. Statistical analyses revealed that salinity is the major factor structuring both bacterial and protistan communities. Salinity also acted as a significant environmental determinant influencing alpha-diversity patterns. Alpha diversity indices for bacterial and protistan communities revealed a species minimum in higher-salinity waters (22.1–32.1). Contrary to the protistan community, the highest bacterial diversity was identified in medium-salinity waters (2.8–18.8), contrasting Remane’s Artenminimum concept. The distribution of major planktonic taxa followed the expected pattern, and the salinity boundary for Syndiniales was specifically identified. These findings revealed the significant effects of salinity on the microbial community across an estuary to ocean transect and the distinct response to salinity between bacterial and protistan communities.
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Wang, Zheng, Fei Zhang, Xianlong Zhang, Ngai Weng Chan, Hsiang-te Kung, Xiaohong Zhou, and Yishan Wang. "Quantitative Evaluation of Spatial and Temporal Variation of Soil Salinization Risk Using GIS-Based Geostatistical Method." Remote Sensing 12, no. 15 (July 27, 2020): 2405. http://dx.doi.org/10.3390/rs12152405.
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Soil salinization is one of the environmental threats affecting the sustainable development of arid oases in the northwest of China. Thus, it is necessary to assess the risk of soil salinity and analyze spatial and temporal changes. The objective of this paper is to develop a temporal and spatial soil salinity risk assessment method based on an integrated scoring method by combining the advantages of remote sensing and GIS technology. Based on correlation coefficient analysis to determine the weights of risk evaluation factors, a comprehensive scoring system for the risk of salinity in the dry and wet seasons was constructed for the Ebinur Lake Wetland National Nature Reserve (ELWNNR), and the risk of spatial variation of soil salinity in the study area was analyzed in the dry and wet seasons. The results show the following: (1) The risk of soil salinity during the wet season is mainly influenced by the plant senescence reflectance index (PSRI), deep soil water content (D_wat), and the effect of shallow soil salinity (SH_sal). The risk of soil salinity during the dry season is mainly influenced by shallow soil salinity (SH_sal), land use and land cover change (LUCC), and deep soil moisture content (D_wat). (2) The wet season was found to have a high risk of salinization, which is mainly characterized by moderate, high, and very high risks. However, in the dry season, the risk of salinity is mainly characterized by low and moderate risk of salinity. (3) In the ELWNNR, as the wet season changes to dry season (from May to August), moderate-risk area in the wet season easily shifts to low risk and risk-free, and the area of high risk in the wet season easily shifts to moderate risk. In general, the overall change in salinity risk of the ELWNNR showed a significant relationship with changes in lake water volume, indicating that changes in water volume play an important role in the risk of soil salinity occurrence. Ideally, the quantitative analysis of salinity risk proposed in this study, which takes into account temporal and spatial variations, can help decision makers to propose more targeted soil management options.
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Cahyarini, Sri Yudawati. "RECONSTRUCTION OF SEAWATER d18O SIGNAL FROM CORAL d18O: A RECORD FROM BALI CORAL, INDONESIA." BULLETIN OF THE MARINE GEOLOGY 25, no. 1 (February 15, 2016): 23. http://dx.doi.org/10.32693/bomg.25.1.2010.22.
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Sea surface salinity (SSS) and precipitation are important climate (paleoclimate) parameters. To obtain long time series data of SSS/precipitation one use coral proxy. In this study, seawater d18O is extracted from d18O content in Bali coral using centering method. The result shows more convincing that d18Obali is influenced by both seawater d18O and sea surface temperature (SST). In the interannual/decadal scale the variation d18Obali clearly shows the variation of seawater d18O, it is supposed that highly variation of precipitation contribute to the seawater d18O variation which mirrored by coral d18Obali.
Keywords: coral d18O, seawater d18O, precipitation, sea surface salinity, sea surface temperature
Salinitas permukaan laut (SSS) dan curah hujan merupakan parameter penting untuk studi iklim maupun paleoiklim (iklim masa lampau). Untuk mendapatkan data dalam urut-urutan waktu (timeseries) yang panjang dari SSS dan curah hujan diperlukan data proksi geokimia dalam koral. Dalam studi ini kandungan d18O dalam air laut dapat di rekonstruksi dari kandungan d18O dalam koral dengan menggunakan metode centering. Hasilnya menunjukkan bahwa d18O dalam koral dipengaruhi oleh kandungan d18O dalam air laut dan SST. Dalam resolusi tahunan dan puluhan tahunan variasi d18Obali dalam koral menunjukkan dengan jelas variasi d18O dalam air laut, hal ini diduga bahwa dalam resolusi tahunan dan puluhan tahunan variasi curah hujan sangat tinggi yang berkontribusi pada tingginya variasi d18Obali dalam air laut sehingga dapat terekam oleh koral.
Kata kunci: d18O koral, d18O air laut, curah hujan, salinitas permukaan laut, suhu permukaan laut.
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Fanini, Lucia, Giovanni M. Marchetti, Anna Baczewska, Kamila Sztybor, and Felicita Scapini. "Behavioural adaptation to different salinities in the sandhopper Talitrus saltator (Crustacea: Amphipoda): Mediterranean vs Baltic populations." Marine and Freshwater Research 63, no. 3 (2012): 275. http://dx.doi.org/10.1071/mf11127.
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The sandhopper Talitrus saltator is common on sandy beaches at different latitudes. Therefore, behavioural variations allowing them to cope with a wide range of environmental variation are expected. To test the hypothesis that behavioural adaptations to natural environments are characterised by different salinities, we compared two behaviours (substrate choice and escape from immersion) of two T. saltator populations from a Mediterranean (high salinity) and a Baltic Sea (low salinity) sandy beach. T. saltator preferred to burrow in the high salinity substrate, irrespective of its beach of origin. Regarding orientation to escape from immersion, Baltic sandhoppers always oriented landwards, whereas Mediterranean sandhoppers showed a significant orientation landwards only when immersed in high salinity sea water. These behavioural traits matched the different environments, and this adaptation capability can be used as a model to analyse the response of a keystone species to environmental changes.
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Kilmatov, T. R. "Cabbeling due to mixing of the Bering Strait and the Chukchi Sea waters on seasonal and climatic scale." Izvestiya TINRO 202, no. 2 (June 30, 2022): 409–13. http://dx.doi.org/10.26428/1606-9919-2022-202-409-413.
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Cabbeling due to mixing of the surface waters from the Bering Strait and the Chukchi Sea is evaluated quantitatively and variations of its impact on seasonal and climatic scale are analyzed. The cabbeling effect increases additionally the mixed water density in 0.059 kg/m3 in summer and in 0.001 kg/m3 in winter. Seasonal variation of the cabelling repeats the seasonal variation of temperature difference between the interacted water masses (ΔT ~ 5,0 оC in summer, ΔT ~ 0,5 оC in winter). This process provides additional energy for sinking of warm and salt mixed water in summer, when it penetrates far into the Arctic. In winter, the temperature difference between the mixing waters is about zero, so the cabbeling almost disappears. Both temperature and salinity have climatic trends in the Chukchi Sea that causes the climate-scale variation of the cabbeling: its impact increases in 0.002 kg/m3 per decade in summer because of climatic heating (~0,13 оC/decade) and salinity decrease (~0.04 psu/decade).
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Polo, Gabriel Furlan, Murillo Ribeiro Freitas, Pamela Stephany Jennings Cunha, Eduardo Pradi Vendruscolo, Cássio de Castro Seron, Murilo Battistuzzi Martins, and Tiago Zoz. "Sensitivity of tuberous roots crops to salinity in a protected environment." Revista de Ciências Agroveterinárias 21, no. 1 (March 4, 2022): 79–84. http://dx.doi.org/10.5965/223811712112022079.
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Soil salinity has been a limiting barrier for the production of vegetables in protected environments. Thus, the understanding of the sensitivity of species to this stress factor must be explored, seeking better growing conditions. Under the hypothesis that beet and radish crops are sensitive to variations in soil salinity, even at low levels, the objective of this work was to evaluate the development and productivity of these two species in soils with different salinities in a protected environment. The experimental design was completely randomized and treatments were formed by the soil salinity levels, obtained with the application of saline solution (NaCl in water), considering the soil electrical conductivity of 0.36 dS m-1 as low salinity, of 1.05 dS m-1 as moderate salinity and 2.43 dS m-1 as elevated. For all variables analyzed, except for the relative chlorophyll index in beet plants, it was found that the increase in soil salinity resulted in significant development losses of beet and radish plants. Therefore, we concluded that beet and radish crops are sensitive to the variation in soil salinity, even in relatively low concentrations, making these species an unattractive choice for cultivation in systems that present this problem.
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Park, J. K., and A. James. "Tidal Variation of Salt Flux and Dispersion in a Polluted Estuary." Water Science and Technology 17, no. 6-7 (June 1, 1985): 1001–15. http://dx.doi.org/10.2166/wst.1985.0197.
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Velocity and salinity data collected during the summer of 1983 in the Tyne estuary are used to investigate the dominant mechanisms for the flux of salt and dispersion. The instantaneous salt flux arises mainly from the combination of velocity fluctuation with the tidal mean salinity, and the instantaneous dispersion results almost entirely from the combination of vertical oscillatory velocity and steady salinity. Of the net downstream salt flux, 92.4% is accounted for by the river discharge. The non-tidal drift appears to be of most importance in the net upstream salt flux. The estuary has a strong vertical salinity gradient and due to the strong secondary flow, has a uniform transverse gradient; thus, the dominant factor in the longitudinal dispersion arises from the vertical shear in the oscillatory tidal current. The dispersion coefficient is highly time-dependent within the tidal cycle as well as a function of distance. The importance of time-varying longitudinal dispersion coefficients are demonstrated in a water quality model by using the sensitivity analysis.
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Branchu, Ph, and L. Bergonzini. "Chloride concentrations in Lake Tanganyika: an indicator of the hydrological budget?" Hydrology and Earth System Sciences 8, no. 2 (April 30, 2004): 256–65. http://dx.doi.org/10.5194/hess-8-256-2004.
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Abstract. On a historical time scale, this paper investigates the effect of hydroclimatic variations on the surface water salinity of Lake Tanganyika, the largest African lake and an open freshwater reservoir. Through annual water and chemical budgets, based on original and bibliographic data, a tracer of the water regime is proposed. Chloride, an inert and conservative element, seems to be the best candidate although its contribution to salinity is small; its use as a tracer of the water regime is validated on seasonal and historical time scales. Seasonally, a monthly water and chloride budget, constructed for an average year has been compared with data acquired in 1973. On a historical time scale, bibliographic data of chloride concentrations, compiled since 1939 have been compared with the level variation curve. The relation between lake level and surface water chloride concentration is significant on both time scales. Hence, the surface salinity/chlorinity of this freshwater lake is sensitive to hydroclimatic variations even if level variations are very limited in comparison with its great depth. This sensitivity is due mainly to the permanent thermo-haline stratification of the lake. Keywords: climate, water budget, hydrochemical budget, Lake Tanganyika, limnology, salinity
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Xie, Wenping, Jingsong Yang, Rongjiang Yao, and Xiangping Wang. "Spatial and Temporal Variability of Soil Salinity in the Yangtze River Estuary Using Electromagnetic Induction." Remote Sensing 13, no. 10 (May 11, 2021): 1875. http://dx.doi.org/10.3390/rs13101875.
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Soil salt-water dynamics in the Yangtze River Estuary (YRE) is complex and soil salinity is an obstacle to regional agricultural production and the ecological environment in the YRE. Runoff into the sea is reduced during the impoundment period as the result of the water-storing process of the Three Gorges Reservoir (TGR) in the upper reaches of the Yangtze River, which causes serious seawater intrusion. Soil salinity is a problem due to shallow and saline groundwater under serious seawater intrusion in the YRE. In this research, we focused on the temporal variation and spatial distribution characteristics of soil salinity in the YRE using geostatistics combined with proximally sensed information obtained by an electromagnetic induction (EM) survey method in typical years under the impoundment of the TGR. The EM survey with proximal sensing method was applied to perform soil salinity survey in field in the Yangtze River Estuary, allowing quick determination and quantitative assessment of spatial and temporal variation of soil salinity from 2006 to 2017. We developed regional soil salinity survey and mapping by coupling limited laboratory data with proximal sensed data obtained from EM. We interpreted the soil electrical conductivity by constructing a linear model between the apparent electrical conductivity data measured by an EM 38 device and the soil electrical conductivity (EC) of soil samples measured in laboratory. Then, soil electrical conductivity was converted to soil salt content (soil salinity g kg−1) through established linear regression model based on the laboratory data of soil salinity and soil EC. Semivariograms of regional soil salinity in the survey years were fitted and ordinary kriging interpolation was applied in interpolation and mapping of regional soil salinity. The cross-validation results showed that the prediction results were acceptable. The soil salinity distribution under different survey years was presented and the area of salt affected soil was calculated using geostatistics method. The results of spatial distribution of soil salinity showed that soil salinity near the riverbanks and coastlines was higher than that of inland. The spatial distribution of groundwater depth and salinity revealed that shallow groundwater and high groundwater salinity influenced the spatial distribution characteristics of soil salinity. Under long-term impoundment of the Three Gorges Reservoir, the variation of soil salinity in different hydrological years was analyzed. Results showed that the area affected by soil salinity gradually increased in different hydrological year types under the impoundment of the TGR.
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Astin, I., and Y. Feng. "Technical Note: Remote sensing of sea surface salinity using the propagation of low-frequency navigation signals." Ocean Science Discussions 11, no. 6 (December 19, 2014): 2971–78. http://dx.doi.org/10.5194/osd-11-2971-2014.
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Abstract. This paper introduces a potential method for the remote sensing of sea surface salinity (SSS) using measured propagation delay of low-frequency Loran-C signals transmitted over an all-seawater path between the Sylt station in Germany and an integrated Loran-C/GPS receiver located in Harwich, UK. The overall delay variations in Loran-C surface waves along the path may be explained by changes in sea surface properties (especially the temperature and salinity), as well as atmospheric dynamics that determine the refractive index of the atmosphere. After removing the atmospheric and sea surface temperature (SST) effects, the residual delay revealed a temporal variation similar to that of SSS data obtained by the European Space Agency's Soil Moisture and Ocean Salinity (SMOS) satellite.
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Furman, Eeva R. "Geographical variation of Balanus improvisus in biochemical and morphometric characters." Journal of the Marine Biological Association of the United Kingdom 70, no. 4 (November 1990): 721–40. http://dx.doi.org/10.1017/s0025315400059002.
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Samples of Balanus improvisus were collected from 15 sites in the Baltic, the west coast of Sweden, the British Isles and North America. They were analysed with horizontal starch gel electrophoresis for 11 loci and with opercular plate morphometry for 10 metrical characters. Analyses of isozyme patterns revealed a high degree of genetic similarity amongst populations. The Baltic sites, however, showed less heterozygote deficiency than the British and American sites indicating higher stability and outcrossing in the Baltic. Morphometric characters showed somewhat more heterogeneity than isozymes. The Baltic was relatively more homogeneous by morphometrical characters than by isozymes compared with the other areas. Both analyses separated to some extent the three geographical regions from each other and clustered sites by salinity. Individuals at low salinity had relatively small opercular openings compared to individuals from high salinity.
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Chakraborty, Arijit, and Anirban Roy. "Water–energy nexus for estuarine systems with seasonal salinity variations: a thermodynamic feasibility analysis of reverse osmosis (RO)–pressure retarded osmosis (PRO) combinations." Water Supply 20, no. 6 (July 1, 2020): 2415–27. http://dx.doi.org/10.2166/ws.2020.144.
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Abstract The underlying philosophy of pressure retarded osmosis (PRO)–reverse osmosis (RO) hybrid technology is the assumption of the availability of ‘fresh’ water for the purpose, which gets severely affected once the fresh-water streams undergo seasonal salinity variations. In the present article, the authors have tried to understand the overall feasibility of PRO-RO combination in such estuarine systems with appreciable variation of seasonal salinity. The article first discusses the feasibility of pretreating the feed of PRO using RO and later understanding the feasibility of PRO as supplemental technology to existing RO units. It was found that pretreating the PRO feed in such estuarine systems was energetically infeasible. However, PRO as supporting technology was found to produce energy of around 0.0994 kWh for 50% recovery. It was also concluded that with a fraction of RO permeate used for PRO, energy savings increase for estuarine systems with seasonal salinity variations.