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Araruama Lagoon is one of the world's largest permanent hypersaline lagoons, and knowledge about the reproduction of fish assemblages is very scarce. This study aimed to evaluate the reproductive functionality of fishes of the Araruama Lagoon in the seasons of 2011, using functional diversity metrics. We also assessed the influence of abiotic factors (salinity, temperature, dissolved oxygen, and pH) on the distribution of sexes and reproductive stages of fish assemblages. Gonads were analyzed in 709 fish across 18 species, mainly females and juveniles. In winter, when there was a lower abundance of species, the highest reproductive incidence (gonadal development/maturation) and high salinity occurred. Summer and spring corresponded with the highest percentage of juveniles. Salinity was the abiotic factor behind the structuring of the community, while the temperature set off the start of the reproductive cycle in autumn. Thus, Araruama Lagoon played a crucial role as a nursery and reproductive area for the fish assemblage. Reproduction in Araruama Lagoon (2011). The vertical arrows indicate the main abiotic variables: temperature and salinity, which structure the fish community. Colors indicate larger (darker) and smaller (lighter) numerical values. The graphs show the percentage of juveniles, males and females, in the seasons corresponding to each season: spring (green), summer (yellow), autumn (orange), and winter (gray). The number of fish next to each graph indicates fish abundance in season, and fish colors indicate diversity. [ABSTRACT FROM AUTHOR]

Simple Summary: The study aimed to confirm the presence of the Na+-K+-2Cl− cotransporter (NKCC) in annelids, a membrane transporter crucial for cell volume regulation, which had not been directly shown before in these worms. Initially, the presence of NKCC was first recovered in silico. Using immunofluorescence, we observed that the NKCC signal was detected in various tissues from four estuarine annelid species from southern Brazil subjected to salinity changes. Two euryhaline species and two stenohaline species were tested. While all species showed NKCC expression, its distribution varied. Euryhaline and free-living species showed widespread NKCC expression along their bodies, while the sedentary stenohaline species had it mainly localized in branchiae and internal tissues. These findings suggest NKCC plays a role in cell volume regulation, particularly in annelids experiencing habitat salinity fluctuations. The expression of the Na+-K+-2Cl− cotransporter (NKCC), widely associated with cell volume regulation, has never been directly demonstrated in annelids. Its putative presence was firstly recovered in silico, and then using immunofluorescence, its signal was retrieved for the first time in different tissues of four species of estuarine annelids from southern Brazil that are regularly subjected to salinity fluctuations. We tested two euryhaline species (wide salinity tolerance), the nereidids Alitta yarae and Laeonereis acuta (habitat salinity: ~10–28 psu), and two stenohaline species (restricted salinity tolerance), the nephtyid Nephtys fluviatilis (habitat salinity: ~6–10 psu), and the melinnid Isolda pulchella (habitat salinity: ~28–35 psu). All four species showed specific immunofluorescent labelling for NKCC-like expression. However, the expression of an NKCC-like protein was not homogeneous among them. The free-living/burrowers (both euryhaline nereidids and the stenohaline nephtyid) displayed a widespread signal for an NKCC-like protein along their bodies, in contrast to the stenohaline sedentary melinnid, in which the signal was restricted to the branchiae and the internal tissues of the body. The results are compatible with NKCC involvement in cell volume, especially in annelids that face wide variations in salinity in their habitats. [ABSTRACT FROM AUTHOR]

The invasion of non-native species has been a chronic problem in reservoirs of hydroelectric plants. Among the species recorded in Brazil, the cnidarian Cordylophora caspia is often misidentified as macrophytes or completely overlooked, although reports state that the colonies obstruct structures and pipes in industrial plants, generating high maintenance costs. In addition to modifying the ecological balance of invaded ecosystems, studies indicated that C. caspia can influence the occurrence of other invasive species, such as Limnoperna fortunei. In this study, we reported two new records for C. caspia in Brazil, the first occurrence in Minas Gerais and Goiás. We described the colonies in detail and reviewed the known geographic distribution of the species in Brazilian waters. We provided the first Brazilian genetic sequences of the species, which were phylogenetically placed into a broad evolutionary inference using C. caspia COI sequences available from different regions of the world. Our results indicate that there is no clear pattern of ecophysiological specialization of main clades regarding salinity that would justify the validation of the nominal C. lacustris for freshwater specimens. High levels of genetic differentiation in the lineages support the existence of multiple cryptic species within the genus Cordylophora. Finally, our ancestral state reconstruction analysis suggested a presumed freshwater origin for C. caspia and independent shifts between fresh and brackish waters. Advances in the study of populations from different regions of the world will be important for further understanding species delimitation, possible routes of invasion, economic impacts, and ecological interactions, including with other invasive species. [ABSTRACT FROM AUTHOR]

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Coastal zones have great environmental and economic importance, since anthropogenic activities are very intense, and consequently, their water quality can be affected. Spatial and temporal variations in physicochemical parameters [temperature, pH, electrical conductivity (EC), salinity, dissolved oxygen (DO) and turbidity] in the surface water from the São Lourenço Watershed, a coastal zone in southern Brazil, were investigated. The influence of Patos Lagoon on the watershed in dry periods was confirmed by the increase in salinity and EC of up to 6.43 and 10,810.00 µS cm−1, respectively. In addition, the DO content with low values at the mouth in some samplings, below the Brazilian legislation, calls attention for the water quality. The principal component analysis showed considerable differences in the lower course by comparison with the upper course and the middle course due to climatic and anthropogenic factors. Results from the monitoring enabled to understand fluvial dynamics involving the system of a watershed that contributes to disposal in coastal lagoons through seasonal and climatic factors. Besides, from a managerial point of view, the obtained results support effective decision-making for the preservation of coastal ecosystems. [ABSTRACT FROM AUTHOR]

The damming in a watershed alters all its fluvial dynamics, affecting the patterns of occurrence and distribution of the fish community. Despite being an important refuge for fish communities in tropical Brazil, the river–estuarine continuum is strongly affected by human activities that have considerably disturbed the natural dynamics. In this study, our objective was to evaluate the spatial and seasonal composition of the fish community in three distinct regions along the river–estuarine continuum of the São Francisco River, raising the hypothesis that the seasonal effect does not interfere in the structuring of the fish assemblage. Our results demonstrate that seasonality does not influence the composition and distribution of fish species in the lower São Francisco, this differentiation is due to the spatial effect of the regions studied. These findings add to the available knowledge about the absence of the seasonal effect in highly dammed environments. [ABSTRACT FROM AUTHOR]

Shallow crystalline groundwater in the semi-arid hinterland of Ceará is brackish or saline with mixed chloride or sodium chloride facies. Very few hydrochemical data are available for the area and the drivers behind this salinity are not clearly identified. In this study, extensive field data collection was performed to provide new information about the hydrogeological functioning and the salinization processes, through the implementation of piezometric, hydrogeochemical, isotopic ( 18O, ²H) and multitracer dating (14C, ³H, CFC, SF6) monitoring. Piezometric and isotopic data evidence fast flow circulation processes and a high contribution of evaporated surface water to aquifer recharge. Multitracer dating shows the groundwater is essentially composed of seasonal vertical infiltration flows that mix with older waters stored in the aquifer. Chemical analyses suggest the groundwater, originally low mineralized, has become progressively saltier due to leaching of salts that were evapoconcentrated in either surface waters or the unsaturated zone during drier periods. [ABSTRACT FROM AUTHOR]

We conducted a geochemical analysis on three sediment cores collected from soda and freshwater lakes in the Pantanal region, in Brazil. Our objective was to identify the primary sources of organic matter associated with the Pleistocene-Holocene transition, as previously documented in that area. The Nhecolandia region, located in the Pantanal, encompasses over 10,000 lakes, with approximately 10% of them exhibiting alkaline characteristics. Soda lakes became highly saline and alkaline after ~ 910 cal yr BP, which influences biogeochemistry and aquatic ecology. They have high electrical conductivity and pH can reach 10.5. In contrast to freshwater, soda lakes are absent of surrounding vegetation. Literature suggests a strong influence by the Last Glacial Maximum on the region. We hypothesized that periods of aridity and increased precipitation influenced the composition of organic matter present in sediments and preserved within these cores. Our analysis focused on examining the presence and distribution of fatty acids, organic carbon content, and total nitrogen. In general, the cores exhibited two distinct parts in terms of organic matter sources: the upper sections of the cores were primarily composed by terrestrial sources, identified by the presence of long-chain fatty acids, while the deeper sections were dominated by aquatic sources, therefore short-chain fatty acids. We did not find significant difference among fatty acid profile that could distinguish freshwater from soda lakes, the only remarkable difference was the occurrence of saturated fatty acids, which is lower in freshwater lake. These findings suggest the occurrence of humid and arid periods in the region. The C/N ratio displayed a similar trend to the fatty acid's profiles, exhibiting an abrupt change that was likely induced by climate variations. Although diagenesis can alter the composition of organic matter and, subsequently, the C/N values, it is noteworthy that the abrupt change observed in the Salina da Ponta (soda lake) core corresponds to 3,200 years BP. This coincides with documented climate changes that occurred during the Holocene. Our study revealed the influence of past climatic conditions on the sources and variations of organic matter in sediment cores from the Pantanal's soda and freshwater lakes. Consideration of diagenesis and climate variations is crucial for interpreting sedimentary records. [ABSTRACT FROM AUTHOR]

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Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present study aimed to evaluate the effects of the foliar application of hydrogen peroxide on the attenuation of salt stress on the growth, photochemical efficiency, production and water use efficiency of 'All Big' bell pepper plants. The experiment was conducted under greenhouse conditions in Campina Grande, PB, Brazil. Treatments were distributed in a randomized block design, in a 5 × 5 factorial scheme, corresponding to five levels of electrical conductivity of irrigation water (0.8, 1.2, 2.0, 2.6 and 3.2 dS m−1) and five concentrations of hydrogen peroxide (0, 15, 30, 45 and 60 μM), with three replicates. Foliar application of hydrogen peroxide at concentration of 15 μM attenuated the deleterious effects of salt stress on photochemical efficiency, biomass accumulation and production components of bell pepper plants irrigated using water with an electrical conductivity of up to 3.2 dS m−1. Foliar spraying of hydrogen peroxide at a concentration of 60 μM intensified the effects of salt stress. The 'All Big' bell pepper was classified as moderately sensitive to salt stress, with an irrigation water salinity threshold of 1.43 dS m−1 and a unit decrease of 8.25% above this salinity level. [ABSTRACT FROM AUTHOR]

In semiarid regions of Brazil, water and/or soil salinity is one of the limiting factors for sour passion fruit production. Low rainfall rates combined with edaphic conditions (high concentrations of soluble salts) intensify deleterious effects on plants. Thus, strategies that minimize the effects of salt stress, e.g., grafting with tolerant species and soil mulching, are extremely important to ensure the expansion of irrigated fruit farming in this region. From this perspective, this study aimed to evaluate the effect of grafting and mulching on the quantum yield, ionic relations, and fruit production of sour passion fruit irrigated with moderately saline water. The experiment was conducted under field conditions in split plots, in a 2 × (2 × 2) factorial arrangement to evaluate the combination of low and moderate salinity water (main plot) with the propagation method (seeds and grafting on P. cincinnata) and without and with plastic mulching (subplots), with four replications and three plants per plot. The ionic relations in passion fruit leaves were increased with the use of rootstocks and plastic mulching under irrigation with moderately saline water. The use of mulching increased the yield of photosystem II in sour passion fruit. The passion fruit plants propagated by seeds had 187.52% more fruits than those grafted onto P. cincinnata. The use of rootstocks with P. cincinnata in sour passion fruit restricted the uptake of Na and Cl but reduced fruit production. [ABSTRACT FROM AUTHOR]

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Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Agriculture in semiarid regions commonly face problems because of salt and availability of irrigation water. Considering this, studies on cultures resistant to salt and water stresses involving sweet sorghum are required. Therefore, the aim was to evaluate the growth and other mechanisms of tolerance to salinity and water deficit in BRS 506 sweet sorghum. The experimental design was conducted in Upanema-RN, Brazil, in randomized blocks, where the isolated and interactive effect of 3 salinity levels, expressed as the electrical conductivity of irrigation water (1.5, 3.8, and 6.0 dS m−1), and 3 irrigation depths (55, 83, and 110% of crop evapotranspiration) were evaluated. During the cycle, sorghum adapted to the salinity and deficit irrigation depth, since stem height reduced only −5.5% with increasing salinity and −11.95% with decreasing irrigation depth, and aerial dry mass was affected by interaction only at the end of the cycle. Proline, total amino acids, and total soluble sugars were not differenced by stresses. Additionally, around 68.71% of total Na+ was at roots at the end of the cycle. In summary, sorghum BRS 506 was more tolerant to salt than water stress and used Na+ compartmentalization in root cells as the main tolerance mechanism. [ABSTRACT FROM AUTHOR]

The watermelon (Citrullus lanatus L.) is a cucurbitaceous plant of great social and economic importance in Brazil, especially in the north-eastern region. However, anthropic actions through the practice of irrigation, fertigation and fertilization in an inadequate way, have potentiated the salinization of the soil becoming this one of the main factors that limit the production and the quality of the fruits. In this work, the effects of the application of mineral fertilization on the salinization of soil cultivated with watermelon were evaluated. The experiment was performed in the city of Petrolina-PE, with four repetitions, using five treatments: (T0) no fertilization, (T1) NPK fertilization, (T2) average dose of NPK practiced by producers, (T3) maximum dose of NPK from producers having potassium chloride as a source of potassium and (T4) maximum dose of NPK from producers having potassium sulfate as a source of potassium, at two different depths: 0.00 - 0.20 m and 0.20 - 0.60 m. The soil chemical attributes analyzed were pH, electrical conductivity (EC), organic matter, phosphorus, potassium, sodium, calcium and magnesium. The increase in the continuous application of mineral fertilizers raised the electrical conductivity values of the soil to levels prejudicial to the crop. [ABSTRACT FROM AUTHOR]

Sesame crops have large economic potential; however, the scarcity of good quality water in the Semiarid region of the Northeast of Brazil can affect production systems, which requires the search for cultivars that can better be adapted to the local conditions. In this context, the objective of this work was to evaluate the germination dynamics of sesame seed lots subjected to different electrical conductivities of the imbibition solution. The experiment was conducted at the Laboratory of Seeds and Seedling Analysis of the Federal University of Campina Grande, Pombal campus, Paraíba, Brazil. A completely randomized design was used, in an 8×6 factorial arrangement, corresponding to eight seed lots (BRS Seda; BRS Seda (S2); BRS G2 (S1); BRS G2 (S2); BRS G3 (S1); BRS G3 (S2); BRS G4 (S1) and BRS G4 (S2), where S1 and S2 represent the grown environments, saline (2.4 dS m-1) and non-saline, respectively; and six electrical conductivities of the imbibition solution (0.3; 1.2; 2.1; 3.0; 3.9; and 4.8 dS m-1), with four replications. The variables seed germination, vigor, germination speed index, mean time for germination, mean germination speed, and radicle length were evaluated. The sesame seeds are sensitive to salinity, regardless of the lot analyzed and their germination power decreases when they are subjected to high salt concentrations. [ABSTRACT FROM AUTHOR]

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Copyright of Revista Brasileira de Agricultura Irrigada - RBAI is the property of Revista Brasileira de Agricultura Irrigada - RBAI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Millet is a crop of great agricultural importance, requires low investment, and it is able to develop rapidly in different environmental conditions, becoming an alternative for small producers in the Brazilian semi-arid region, mainly for forage production in times of water resources scarcity. The analysis of salinity effects on irrigation water in agricultural cultivation areas in semi-arid regions is extremely important for the elaboration, implementation, and execution of adequate management proposals. The effect of different salt concentrations on irrigation water during the emergence of millet seedlings (Pennisetum glaucum L. BR.) was studied. The experiment was set up in a greenhouse at the Federal Rural University of Pernambuco, Academic Unit of Serra Talhada, State of Pernambuco, Northeast region, Brazil, in the period from May 30 to June 11, 2018, using a completely randomized design with four treatments and five replicates, with 24 seeds in each plot. Treatments consisted of four saline concentrations (0 (destilled water), 4, 8, and 12 dS m-1) achieved by adding sodium chloride (NaCl) in the water. Variables assessed were seedling emergence percentage, emergence speed index, shoot length, root length, root dry mass, and dry shoot mass. Increasing salt concentrations in the irrigation water negatively affects the emergence of millet seedlings; thus, the maximum saline concentration recommended is 8 dS m-1. [ABSTRACT FROM AUTHOR]

Salt stress impairs the early development of the peanut crop. However, the intensity of its effects depends on other factors, such as species or cultivar. The objective of this study has been to evaluate the effects of salt stress on the early growth of peanut genotypes. The experiment was carried out in an agricultural greenhouse under pot conditions at the University for International Integration of the Afro-Brazilian Lusophony in Redenção/CE/Brazil. The treatments were: two levels of electrical conductivity of the irrigation water (2.0 and 5.0 dS m-1) and five peanut genotypes (cultivar BR-1, Accession 08, 28, 43, and 130). They were implemented in a factorial design (2 × 5) under a completely randomized design with five replications. The following variables were evaluated at 34 days after sowing: number of leaves, plant height, leaf area, stem diameter, shoot dry mass, electrical conductivity of the saturated soil extract, and pH. Irrigation water with a conductivity of 5.0 dS m-1 reduced leaf area, plant height, stem diameter, number of leaves, and shoot dry matter of the peanut genotypes cultivar BR-1, Accessions 08, 28, 43, and 130. It also raised the pH and electrical conductivity of the saturated soil extract in relation to the water with lower conductivity (2.0 dS m-1). [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

High salt concentration in irrigation water is often a limiting factor to tomato production in Brazil. However, there is limited information available regarding the tolerance of tomato genotypes to saline irrigation. An experiment was conducted in a protected environment using a randomized block design with four replications. Treatments consisted of 12 tomato genotypes cultivated in an environment with varying levels of salt stress. Moderate and severe salt stress affected plant height, transversal and longitudinal diameter of fruit, fresh mass, yield, and number of tomato fruit per plant. Cluster analysis, stability, and adaptability provided the best estimates to identify the most adaptable genotype to saline stress, with the genotypes Maestrina, Onix, Pizzadoro, and Shanty being the best adapted to moderate and severe saline stress conditions. The genotypes Maestrina, Onix, Pizzadoro, and Shanty were identified as most adaptable to and stable under salt stress. Sodium absorption increased as irrigation salinity increased. In addition, P, K, and Ca concentration decreased under salt stress, which caused damage to all yield components and plant nutrition. The genotype Onix was more tolerant to the effects of moderate saline irrigation, while the genotypes Sheena, Sperare, Santa Clara, IPA 6, and Dominador had lower losses under severe salt stress conditions. [ABSTRACT FROM AUTHOR]

The Vendée Globe is the world's most famous solo, non-stop, unassisted sailing race. The Institute of Marine Sciences and the Barcelona Ocean Sailing Foundation installed a MicroCAT on the One Ocean One Planet boat. The skipper, Dídac Costa, completed the round trip in 97 days, from 8 November 2020 to 13 February 2021, providing one measurement of temperature and conductivity every 30 s during navigation. More than half of the ship's route was in the sub-Antarctic zone, between the tropical and polar fronts, and it passed through areas of oceanographic interest such as Southern Patagonia (affected by glacier melting), the Brazil–Malvinas confluence, the Southern Pacific Ocean, and the entire Southern Indian Ocean. This sailing race gave a rare opportunity to measure in-situ sea surface salinity in a region where satellite salinity measurements are not reliable. Due to the decreased sensitivity of brightness temperature to salinity in cold seas, retrieving sea surface salinity at high latitudes remains a major challenge. This paper describes how the data are processed and uses the data to validate satellite salinity products in the sub-Antarctic zone. The sailing race measurements represent surface information (60 cm depth) not available from drifters or Argo floats. Acquiring measurements using round-the-world sailing races would allow us to analyse the evolution of ocean salinity and the impact of changes in the ice extent around Antarctica. [ABSTRACT FROM AUTHOR]

Rice production (Oryza sativa L.) is among the most economically important activities in the world. However, soil and salinity coming from irrigation water reduce rice yield. Therefore, the identification and/or development of salt-tolerant rice genotypes is a strategy to minimize this problem. The development of new genotypes depends on the presence of genetic diversity, and understanding the heritability of a desired trait can help in the selection process. Thus, this study aimed to identify superior genotypes, analyze the genetic diversity and estimate the heritability for salinity tolerance at the seedling stage in rice genotypes used in Brazil. For this, seedlings of 69 genotypes were kept in hydroponic solution with 40 mM NaCl (4 dSm-1) for seven days. Shoot length, root length, shoot dry weight, and root dry weight) were evaluated and the results were converted into relative performance. Tolerant and moderately salt-tolerant genotypes were identified at the seedling stage, which can be used in breeding programs and can be cultivated in high salinity areas. Principal component analysis showed the presence of genetic diversity for salinity response. Finally, it was shown that most of the observed variation is of genetic origin, which can make the breeding process less difficult. [ABSTRACT FROM AUTHOR]

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Jatropha curcas is a common species in Brazil, potentially being an option to produce oil for bioenergetic purposes. Around the world, J. curcas has been cultivated in areas of low fertility, in the presence of salts, and with the use of brackish groundwater. Salt stress can hinder the absorption of nutrients and allow entry of ions in toxic concentrations, affecting the development and productivity of plants. This study aimed to evaluate the effect of salinity on the gaseous exchange and the dynamics of some mineral nutrients in the leaves, stems and roots of J. curcas, subjected to two levels of NaCl (0 and 150 mM) in four genotypes: CNPAE183 (tolerant-like), JCAL171 (sensitive-like) and CNPAE133 and CNPAE266 (confused responses to tolerance). Salt treatment promotes a strong reduction in photosynthesis and plant height in all genotypes, although more drastic in CNPAE266 (77.5% and 70% respectively). Additionally, NaCl reduced the content of manganese, calcium, potassium and phosphorus in the leaves, elements linked to gas exchange. The salt-tolerant-like (CNPAE183) and salt-sensitive-like (JCAL171) transcriptome matched the applied sequences, with few chimeric sequences and novel transcripts with no similarities. [ABSTRACT FROM AUTHOR]

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Uca maracoani is a fiddler crab found in estuaries along the western Atlantic coast, with a notable preference for euhaline environments. This study aimed to analyze the population structure and dynamics of this species in an estuary on the North Coast of Brazil, specifically in an area of the upper estuary where seasonal rainfall fluctuations result in significant changes in salinity. Monthly crab samples were taken from December 2013 to November 2015, together with measurements of environmental variables, such as water and climate parameters. The population maintains a balanced sex ratio; however, males are generally larger, with lower mortality rates and longer lifespans than females. Reproduction is continuous but mainly takes place in the dry season when salinity levels are higher (above 12‰). Higher crab densities have been observed during the rainy season when, despite lower salinity levels (below 10‰), the conditions for survival (food availability and milder climate) seem to be more favorable. The estimated average annual biomass and production for the population were 2.62 g AFDM m−2 and 5.43 g AFDM m−2 year−1, respectively, characterized by a high turnover rate (P/B = 2.10 year−1). Our results suggest that U. maracoani has thriving populations in the Amazon coast's mangroves, benefiting from the vast muddy intertidal zone and the high organic content delivered by the estuaries. • Uca maracoani thrives in estuarine zone that are seasonally oligohaline. • Higher densities of the crabs occurred during the rainy season when salinity is lower. • Reproduction mainly takes place in the dry season when salinity is higher. • The species has a population with high production despite salinity fluctuations. [ABSTRACT FROM AUTHOR]

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Irrigation water salinity is one of the most limiting factors to agriculture in the Northeast region of Brazil, compromising photosynthesis in most crops, especially in the early growth phase, thus requiring the development of research to mitigate its harmful effects. In this context, this study aimed to evaluate the effects of nitrogen fertilization for the mitigation of the salinity on the physiology of sugar apple seedlings. The experimental design was in randomized blocks, using five levels of electrical conductivity of irrigation water (0.5; 1.15; 2.75; 4.35 and 5.0 dS m-1) and five nitrogen levels via foliar application (0.0; 0.33; 1.15; 1.97 and 2.3 g L-1) in four replications and two plants per plot, totaling nine combinations generated by the Box Central Composite Design. Despite stimulating chlorophyll formation 70 DAS, saline water inhibits the fluorescence of chlorophyll a in photosystem II. Foliar nitrogen fertilization at the level of 1.62 g L-1 mitigates the effects of salinity on the gas exchange properties of sugar apple seedlings. The fluorescence activity and chlorophyll indices show positive responses to foliar nitrogen fertilization in sugar apple seedlings 70 DAS. [ABSTRACT FROM AUTHOR]

Mangroves are coastal ecosystems, subject to limiting environmental conditions and constituted by tree communities. The tree species have adaptations to develop under such stress conditions. The sclerophylly is a response to environments with multiple stresses. In the mangrove forests, these stresses are induced mainly by salinity, frequency of tidal influence, soil waterlogging, and nutrient limitation. The aim of the study was to establish if the degree of sclerophylly, expressed in leaf morphology and nutrient contents in tree species of mangroves is associated with edaphic and salinity conditions. The study was performed in one mangrove at Paraná state, Brazil, where two plots were sampled (fringe and interior). Leaves of 15 individuals of each species (Avicennia schaueriana, Laguncularia racemosa and Rhizophora mangle) for each plot (fringe and interior) were collected for chemical and morphological analysis. Soil samples adjacent to each selected tree were collected to perform fertility analyses. The fringe soils samples present higher carbon and organic matter, C:P ratio, pore water salinity and sand predominance. The specific leaf area (SLA) showed that species have sclerophyllous leaves in different degrees: L. racemosa > R. mangle > A. schaueriana. The different degrees of sclerophylly found among the studied species and among plots indicated that each species has its own strategies and that they manifest themselves distinctly in morphological and physiological terms, even when developing under similar environmental conditions. [ABSTRACT FROM AUTHOR]

In this study, the relationship between fish assemblage structure and environmental factors was analyzed in a bay in southern Brazil. Fish were collected every two months between February and December 2002 at six sampling sites using bottom trawl nets. Abiotic data (salinity, temperature, rainfall, and depth) and biotic data (number of individuals, biomass, and total length of individuals from each species) were obtained. In total, 56 fish species representing 27 families were collected. Assemblage structure varied with seasonality, as was evidenced by the variation in temperature and rainfall in each season. Catches showed a high abundance of demersal fishes, particularly Genidens genidens, Eucinostomus gula, and E. argenteus. [ABSTRACT FROM AUTHOR]

In an estuary of a neotropical region located in Brazil, Urochloa arrecta occurs only in the area of freshwater. Nonetheless, information about the capacity of this population to invade areas considered inhospitable, i.e., saltwater, is scarce. In this sense, the aim of this study was to evaluate the effect of intermediate (20 ppt) and high (30 ppt) salinity on individuals from a population of U. arrecta located in the freshwater region of an estuarine ecosystem. Analyses of plant biomass, nitrogen, phosphorus, malondialdehyde (MDA) and hydrogen peroxide content were evaluated as possible indicators of tolerance to salt stress. Our results showed that salinity reduced growth and increased oxidative stress. However, under conditions of intermediate salinity, U. arrecta individuals showed a biomass gain greater than 60%, MDA content similar to that in freshwater, and higher nitrogen absorption and assimilation. We conclude that U. arrecta probably presents physiological adjustments that allow its survival at intermediate salinity. Thus, the ability of this species to expand in this area alerts to the importance of studies that seek to adopt policies for the control or management of the species in saline ecosystems. [ABSTRACT FROM AUTHOR]

Trait-based classifications can efficiently capture species' responses to environmental gradients and their impacts on ecosystem functioning. Thus, the clustering of phytoplankton species into functional groups can improve the understanding of their relationships with the environment and help to predict their response to environmental changes. Accordingly, this study aimed to create habitat templates of Reynolds phytoplankton functional groups (RFGs) in tropical drinking water reservoirs to describe, explain, and predict their occurrence and formation of blooms. We analyzed the structure of RFGs in 10 tropical reservoirs, in humid and semiarid regions of Brazil, and defined their relationships with 10 environmental variables. We designated the habitat template based on niche differentiation, thresholds for the occurrences and bloom formation, cluster analyses, and generalized additive models. We identified 136 species, assembled in 20 RFGs. Six groups of habitat templates were recognized based on environmental conditions and dominant RFGs, usually represented by bloom-forming species of cyanobacteria, dinoflagellates, green algae, and diatoms. The functional groups D, X1, and P presented the most restrictive occurrences, while RFGs M and SN displayed the widest, occurring in almost all sets of conditions. Moreover, salinity was the best predictor of RFGs' biomass (higher R2), followed by depth, soluble reactive phosphorus, irradiance, water transparency, and dissolved inorganic nitrogen. Our approach improves the understanding of how RFGs interact with environmental gradients in tropical reservoirs, helping water managers to adopt sustainable practices to control algal blooms, based on predictions of the future state of dominance. [ABSTRACT FROM AUTHOR]

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Cashew is a fruit species of great economic importance in Brazil, especially in its Northeast region. However, abiotic factors such as water and soil salinity stand out as limiting parameters for this crop, affecting all phases of development as well as physiological and biochemical processes. In this scenario, the use of products to mitigate such damage becomes a necessary practice, with silicon and potassium being viable alternatives. From this perspective, the present study aimed to evaluate the photochemical efficiency of cashew rootstocks subjected to water salinity and foliar application of potassium silicate. A randomized block design arranged in a 5x5 factorial with four replications and two plants per plot was used in the experiment. Treatments consisted of different levels of irrigation water electrical conductivity - ECw (0.3, 1, 1.7, 2.4, and 3.1 dS m-1) and potassium silicate concentrations (0, 250, 500, 750, and 1000 mg L-1) supplied via foliar application. Irrigation water salinity levels from 2.1 dS m-1 reduce the photochemical efficiency of photosystem II by at least 10%, consequently affecting the photosynthetic apparatus of cashew plants 70 days after sowing. The potassium silicate concentration of 250 mg L-1 increases the quantum yield of cashew plants under salt stress conditions. [ABSTRACT FROM AUTHOR]

The Guanabara Bay (BG) localized in Rio de Janeiro city (Rio de Janeiro/Brazil) is on of the most important estuaries of the country showed intense port activity and from the start of century XIX a picture of intense degradation due mainly to fur eviction of domestic and industrial waste. Between all the environmental passives promoted per port activity stand out the biodiversity loss and exotic species introduction as alterations of levels of salinity, temperature, and pH. The present study has the objective to analyze possible correlations on standards of pH, temperature, and salinity in the port area of Rio de Janeiro from 2006 to 2018. 22 surface water sampling waters campaigns were carried out at five points. The salinity and pH varied significantly between the points sampled while for the temperature not showed significant difference. The variations in the parameters can be explained by the tidal regime and by the pluviometric standard shown in the time. The correlations occurred between the salinity and pH in a positive way at points P2, P3, and P5. Continuous monitoring should be carried out to detect possible fluctuations since pH, salinity and temperature influence local biodiversity. [ABSTRACT FROM AUTHOR]

In Santa Catarina State, Brazil, rice is predominantly cultivated in irrigated systems, and irrigation water is generally collected directly from watercourses. Irrigated rice crops, which are sensitive to water salinity, form the basis of the economy of the Mampituba River Basin region, southern Brazil. This study aimed to assess salinity fluctuations in waters collected from the Mampituba River for irrigation of rice crops during the four seasons of the year. For salinity determination, water samples were collected from six sites along the river course, from the source to the mouth. Three subsamples were collected at each site, with a mean interval of 15 days between collections, beginning in May 2016 and ending in April 2017. Samples were evaluated for electrical conductivity (EC). Assessment of salinity damage was performed in seedlings of rice cultivars 'IRGA 417' and 'EPAGRI 106'. When seedlings reached the S2 stage, they were transplanted into flooded soil at different saline concentrations. EC values ranged from 224 to 20,120 µS cm-1 over the experimental period, being higher at sites closer to the sea. The highest salinity values were recorded between November 2016 and January 2017. It was possible to observe an inverse relationship between rainfall and water salinity. Salinity causes damage to rice plants, particularly seedlings. Symptoms include leaf tip chlorosis, leaf curling, and necrosis of old leaves. It is important for rice farmers to understand salt wedge fluctuations within their estuary as well as variations in salinity levels at different sites and times of the year. [ABSTRACT FROM AUTHOR]

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Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Agricultura Irrigada - RBAI is the property of Revista Brasileira de Agricultura Irrigada - RBAI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Brasileira de Agricultura Irrigada - RBAI is the property of Revista Brasileira de Agricultura Irrigada - RBAI and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Coastal wetlands are known for their diverse ecosystems, yet their soil characteristics are often misunderstood and thought to be monotonous. These soils are frequently subjected to saline water saturation, leading to unique soil processes. However, the combination and intensity of these processes can vary considerably across different ecosystems. In this study, we hypothesize that these diverse soil processes not only govern the geochemical conditions in coastal ecosystems but also influence their ability to deliver ecosystem services. To test this hypothesis, we conducted soil analyses in mangroves, seagrass meadows, and hypersaline tidal flats along the Brazilian coast. We used key soil properties as indicators of soil processes and developed a conceptual model linking soil processes and soil-related ecosystem services in these environments. Under more anoxic conditions, the intense soil organic matter accumulation and sulfidization processes in mangroves evidence their significance in terms of climate regulation through organic carbon sequestration and contaminants immobilization. Similarly, pronounced sulfidization in seagrasses underscores their ability to immobilize contaminants. In contrast, hypersaline tidal flats soils exhibit increased intensities of salinization and calcification processes, leading to a high capacity for accumulating inorganic carbon as secondary carbonates (CaCO 3 ), underscoring their role in climate regulation through inorganic carbon sequestration. Our findings show that contrary to previously thought coastal wetlands are far from monotonous, exhibiting significant variations in the types and intensities of soil processes, which in turn influence their capacity to deliver ecosystem services. This understanding is pivotal for guiding effective management strategies to enhance ecosystem services in coastal wetlands., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

This article assesses the environmental impacts of aquatic biota cultivation, focusing on shrimp farming in Brazil's Northeast, as this practice has proven to be one of the main sources of economic growth in the region. For this purpose, sediment samples were collected from areas impacted and not directly impacted by shrimp farming, and concentrations of key geochemical parameters such as salinity, various elements (K, P, Cu, Mn, Pb, Zn, Al, Ca, Fe, Mg, and Na), and natural radionuclides (K-40, Ra-226 and Ra-228) were compared using statistical tools. Element concentrations were determined using ICP-OES, and naturally occurring radionuclide concentrations were obtained through gamma spectrometry. Statistical tests, such as ANOVA and/or Mann-Whitney, cluster analysis, and principal component analysis, were applied to the results. Additionally, the ERICA Tool software was employed to estimate deleterious effects on both human and non-human biota. Descriptive statistics reveal variability in sediment parameters around shrimp farming. ANOVA and Mann-Whitney tests compare concentrations of shrimp farm sediment and not directly impacted sediment, showing non-significant differences for most elements. pH and salinity, crucial for shrimp health, exhibit higher values in shrimp farm sediment. Alkali and alkaline earth metals, including K and Na, show no significant differences. Factor and cluster analyses suggest that certain elements, mainly radionuclides, are influenced by sediment variability. Hazard indices for naturally occurring radionuclides indicate negligible risk to both human and non-human biota, reinforcing the absence of adverse effects from shrimp farming activities. This study provides a comprehensive analysis of the environmental impacts of shrimp farming, emphasizing the importance of monitoring geochemical parameters for coastal environmental management., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Copyright of Revista Brasileira de Engenharia Agricola e Ambiental - Agriambi is the property of Revista Brasileira de Engenharia Agricola e Ambiental and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Caatinga is the property of Revista Caatinga and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Basil is a medicinal and spice plant widely used in the Northeast region of Brazil. However, its production can be affected by the soil salinity and water used for irrigation. For the development of plants in saline conditions to occur, it is necessary that their nutritional status is adequate. Thus, the objective was to evaluate the effect of nitrogen fertilization on growth and gas exchange of purple basil submitted to salinity. The experiment was performed at the Federal University of Paraíba, adopting a randomized block design in an incomplete 5 x 5 factorial scheme, with five electrical conductivities (ECw = 0.0, 0.81, 2.75, 4.69 and 5.50 dS m−1) and five doses of nitrogen (N = 0.00, 58.58, 200.00, 341.42 and 400.00 mg L−1), generated through the central composite design. Plant height, number of leaves, stem diameter, leaf area and root length were evaluated at 45 days. Stomatal conductance, net CO2 assimilation rate, transpiration, water use efficiency, intrinsic water use efficiency, intrinsic efficiency of carboxylation and leaf temperature were evaluated. The data were analyzed through analysis of variance and regression. Foliar N fertilization attenuated the harmful effect of salt stress, increasing stem diameter, net CO2 assimilation rate, intrinsic efficiency of carboxylation and leaf temperature. Salinity reduced the growth of basil plants as the ECw rised. Gas exchange was stimulated by salinity and reduced by the foliar N fertilization. The number of leaves and leaf area increased with nitrogen fertilization. [ABSTRACT FROM AUTHOR]