scholarly journals Larval fish dispersal along an estuarine–ocean gradient

2017 ◽  
Vol 74 (9) ◽  
pp. 1462-1473 ◽  
Author(s):  
S. Ramos ◽  
C.B. Paris ◽  
M.M. Angélico
Keyword(s):  
Chlorophyll A ◽  
High Salinity ◽  
Larval Fish ◽  
Salinity Gradient ◽  
Spatial Gradient ◽  
Total Particulate Matter ◽  
Dissolved Carbon ◽  
Management Plans ◽  
Northwestern Iberian Peninsula ◽  
Fish Dispersal

The present study investigated the larval fish dispersal along an estuarine–ocean gradient to explore connectivity between ocean and estuaries. During spring 2009, a combined ocean–estuarine survey was conducted along the Lima estuarine salinity gradient and in two transects off the adjacent coast (northwestern Iberian Peninsula), until the 100 m isobaths. Salinity, total particulate matter, particulate organic matter, total dissolved carbon, and dissolved organic carbon reached higher values at the ocean, and chlorophyll a and nutrients increased at the estuary. From the total 56 taxa identified, 14 were present along the gradient, including estuarine species (ES), marine stragglers (MS), and migrants (MM). Canonical correspondence analysis showed that species were separated along the gradient according to their ecological functional classification. MM associated with high salinity were separated from ES correlated with lower salinities and high chlorophyll a concentrations of inner estuary. Flounder (Platichthys flesus) showed a typical spatial gradient of MM, with abundance increasing from the ocean towards inner estuary. The dispersal of larvae along the Lima estuarine–ocean gradient was indicative of connectivity between habitats, emphasizing the need to consider this feature in management plans, mainly for species exploited by commercial fisheries.

scholarly journals Larval Fish Community in the Northwestern Iberian Upwelling System during the Summer Period

Oceans ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 700-722
Author(s):  
Sonia Rábade Uberos ◽  
Alba Ruth Vergara Castaño ◽  
Rosario Domínguez-Petit ◽  
Fran Saborido-Rey
Keyword(s):  
Community Composition ◽  
Fish Community ◽  
Larval Fish ◽  
Life Stages ◽  
Early Life Stages ◽  
Summer Period ◽  
Specific Composition ◽  
Larval Production ◽  
High Diversity ◽  
Northwestern Iberian Peninsula

The Galician shelf (northwestern Iberian Peninsula) is a highly dynamic area with an important multi-species fisheries industry that exploits resources from several habitats, characterized by being not only highly diverse, rich, and productive but also seasonally and interannually variable. Early life stages of different species are distributed throughout the year, with fluctuating abundances and community composition. Likewise, the influence of environmental factors and processes on larval production and survival remains unknown. Sampling was carried out in July 2012, and all the larvae obtained were identified to establish the specific composition of the community in a summer upwelling scenario. The results show no zonation in the species distribution, a consequence of the mixing effects of the upwelling and eddies, with high diversity but low abundance, which render in a slight predominance of a few species. Due to the dependence of planktonic populations on upwelling events, which was not highly pronounced in 2012, we cannot conclude that this was a typical conformation of the Galician summer larval fish community, but it is a first approach to comprehend the community composition.

scholarly journals Large seasonal and spatial variation in nano- and microphytoplankton diversity along a Baltic Sea—North Sea salinity gradient

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Malin Olofsson ◽  
James G. Hagan ◽  
Bengt Karlson ◽  
Lars Gamfeldt
Keyword(s):  
Community Structure ◽  
Temporal Variation ◽  
High Salinity ◽  
Salinity Gradient ◽  
Seasonal Succession ◽  
Phytoplankton Diversity ◽  
Cell Abundance ◽  
Low Salinity ◽  
Spatio Temporal ◽  
The Impact

Abstract Aquatic phytoplankton experience large fluctuations in environmental conditions during seasonal succession and across salinity gradients, but the impact of this variation on their diversity is poorly understood. We examined spatio-temporal variation in nano- and microphytoplankton (> 2 µm) community structure using almost two decades of light-microscope based monitoring data. The dataset encompasses 19 stations that span a salinity gradient from 2.8 to 35 along the Swedish coastline. Spatially, both regional and local phytoplankton diversity increased with broad-scale salinity variation. Diatoms dominated at high salinity and the proportion of cyanobacteria increased with decreasing salinity. Temporally, cell abundance peaked in winter-spring at high salinity but in summer at low salinity. This was likely due to large filamentous cyanobacteria blooms that occur in summer in low salinity areas, but which are absent in higher salinities. In contrast, phytoplankton local diversity peaked in spring at low salinity but in fall and winter at high salinity. Whilst differences in seasonal variation in cell abundance were reasonably well-explained by variation in salinity and nutrient availability, variation in local-scale phytoplankton diversity was poorly predicted by environmental variables. Overall, we provide insights into the causes of spatio-temporal variation in coastal phytoplankton community structure while also identifying knowledge gaps.

scholarly journals Mesoscale, cyclonic eddies as larval fish habitat along the southeast United States shelf: a Lagrangian description of the zooplankton community

2009 ◽  
Vol 67 (3) ◽  
pp. 403-411 ◽  
Author(s):  
J. J. Govoni ◽  
J. A. Hare ◽  
E. D. Davenport ◽  
M. H. Chen ◽  
K. E. Marancik
Keyword(s):  
United States ◽  
Chlorophyll A ◽  
Larval Fish ◽  
Fish Habitat ◽  
Zooplankton Community ◽  
The United States ◽  
Continuous Series ◽  
Lagrangian Description ◽  
Southeast United States ◽  
Chlorophyll A Concentration

Abstract Govoni, J. J., Hare, J. A., Davenport, E. D., Chen, M. H., and Marancik, K. E. 2010. Mesoscale, cyclonic eddies as larval fish habitat along the southeast United States shelf: a Lagrangian description of the zooplankton community. – ICES Journal of Marine Science, 67: 403–411. The Charleston Gyre region is characterized by continuous series of cyclonic eddies that propagate northeastwards before decaying or coalescing with the Gulf Stream south of Cape Hatteras, NC, USA. Over 5 d, chlorophyll-a concentration, zooplankton displacement volume, and zooplankton composition and abundance changed as the eddy moved to the northeast. Surface chlorophyll-a concentration decreased, and zooplankton displacement remained unchanged as the eddy propagated. Zooplankton taxa known to be important dietary constituents of larval fish increased in concentration as the eddy propagated. The concurrent decrease in chlorophyll-a concentration and static zooplankton displacement volume can be explained by initial stimulation of chlorophyll-a concentration by upwelling and nutrient enrichment near the eddy core and to possible grazing as zooplankton with short generation times and large clutch sizes increased in concentration. The zooplankton community did not change significantly within the 5 d that the eddy was tracked, and there was no indication of succession. Mesoscale eddies of the region are dynamic habitats as eddies propagate northeastwards at varying speeds within monthly periods. The abundance of zooplankton important to the diets of larval fish indicates that the region can provide important pelagic nursery habitat for larval fish off the southeast coast of the United States. A month of feeding and growth is more than half the larval duration of most fish spawned over the continental shelf of the southeastern United States in winter.

Salinity tolerances of three succulent halophytes (Tecticornia spp.) differentially distributed along a salinity gradient

2016 ◽  
Vol 43 (8) ◽  
pp. 739 ◽  
Author(s):  
Louis Moir-Barnetson ◽  
Erik J. Veneklaas ◽  
Timothy D. Colmer
Keyword(s):  
Growth Rates ◽  
Shoot Growth ◽  
High Salinity ◽  
Salt Lake ◽  
Salinity Gradient ◽  
Saline Soils ◽  
Low Salinity ◽  
Substrate Limitation ◽  
Extreme Salinity ◽  
Osmotic Potentials

We evaluated tolerances to salinity (10–2000 mM NaCl) in three halophytic succulent Tecticornia species that are differentially distributed along a salinity gradient at an ephemeral salt lake. The three species showed similar relative shoot and root growth rates at 10–1200 mM NaCl; at 2000 mM NaCl, T. indica subsp. bidens (Nees) K.A.Sheph and P.G.Wilson died, but T. medusa (K.A.Sheph and S.J.van Leeuwen) and T. auriculata (P.G.Wilson) K.A.Sheph and P.G.Wilson survived but showed highly diminished growth rates and were at incipient water stress. The mechanisms of salinity tolerance did not differ among the three species and involved the osmotic adjustment of succulent shoot tissues by the accumulation of Na+, Cl– and the compatible solute glycinebetaine, and the maintenance of high net K+ to Na+ selectivity to the shoot. Growth at extreme salinity was presumably limited by the capacity for vacuolar Na+ and Cl– uptake to provide sufficiently low tissue osmotic potentials for turgor-driven growth. Tissue sugar concentrations were not reduced at high salinity, suggesting that declines in growth would not have been caused by inadequate photosynthesis and substrate limitation compared with plants at low salinity. Equable salt tolerance among the three species up to 1200 mM NaCl means that other factors are likely to contribute to species composition at sites with salinities below this level. The lower NaCl tolerance threshold for survival in T. indica suggests that this species would be competitively inferior to T. medusa and T. auriculata in extremely saline soils.

Evaluation of the Salinity Gradient Concept in Surfactant Flooding

1983 ◽  
Vol 23 (03) ◽  
pp. 486-500 ◽  
Author(s):  
G.J. Hirasaki ◽  
H.R. van Domselaar ◽  
R.C. Nelson
Keyword(s):  
Active Region ◽  
Phase Behavior ◽  
Aqueous Phase ◽  
Surfactant Concentration ◽  
High Salinity ◽  
Salinity Gradient ◽  
Type Ii ◽  
Middle Phase ◽  
Optimal Salinity ◽  
Type Iii

Abstract Salinity design goals are to keep as much surfactant as possible in the active region and to minimize surfactant possible in the active region and to minimize surfactant retention. Achieving these is complicated becausecompositions change as a result of dispersion, chromatographic separation of components distributed among two or more phases, and retention by adsorption onto rock and/or absorption in a trapped phase-.in the presence of divalent ions, optimal salinity is not constant but a function of surfactant concentration and calcium/sodium ratio: andthe changing composition of a system strongly influences transport of the components. A one-dimensional (ID) six-component finite-difference simulator was used to compare a salinity gradient design with a constant salinity design. Numerical dispersion was used to evaluate the effects of dispersive mixing. These simulations show that, with a salinity gradient, change of phase behavior with salinity can be used to advantage both to keep surfactant in the active region and to minimize retention. By contrast, under some conditions with a constant salinity design. it is possible to have early surfactant breakthrough and/or large surfactant retention. Other experiments conducted showed that high salinity does retard surfactant, and, if the drive has high salinity. a great amount of surfactant retention can result. The design that produced the best recovery had the water flood brine over optimum and the drive under optimum; the peak surfactant concentration occurred in the active region and oil production ceased at the same point. Introduction The phase behavior of surfactant/oil/brine systems for different salinities is shown in Fig. 1. Low salinities. called "underoptimum" or "Type II(−)" phase behavior, are shown at the top of Fig. 1. In this kind of system, surfactant is partitioned predominantly into the aqueous phase. predominantly into the aqueous phase. High salinities, called "overoptimum" or "Type II(+)" phase behavior, are shown at the bottom of Fig. 1. In this kind of system, surfactant is partitioned predominantly into the oleic phase. When the oleic phase predominantly into the oleic phase. When the oleic phase has a low oil concentration, the oil is said to be "swollen" by the surfactant and brine. At moderate salinities, the system can have up to three phases and is called "Type III." This is illustrated in the phases and is called "Type III." This is illustrated in the middle of Fig. 1. The salinity at which the middle phase has a WOR of unity is called "optimal salinity" because the lowest interfacial tensions (IFT's) usually occur near this salinity. As salinity increases, there is a steady progression from Type II(−) to Type III to Type II(+) phase behavior. The middle-phase composition moves from the brine side of the diagram to the oil side. The two-phase regions that correspond to the Type II(−) and Type II( +) systems can be seen above the three-phase region in Fig. 1.

scholarly journals Mahameru Soybean (Glycine max) Cultivar, High Salinity Tolerant

2018 ◽  
Vol 10 (1) ◽  
pp. 23-31
Author(s):  
Juwarno Juwarno ◽  
Tata Brata Suparjana ◽  
Muachiroh Abbas
Keyword(s):  
Chlorophyll A ◽  
Salinity Stress ◽  
High Salinity ◽  
Dry Weight ◽  
Salinity Treatment ◽  
Soybean Production ◽  
Anatomy And Physiology ◽  
Salinity Levels ◽  
Chlorophyll A And B ◽  
Soybean Plants

Mahameru cultivar is high salinity tolerant cultivar. The previous study result showed Mahameru cultivar could tolerate 140mM NaCl, but Cilacap Coast salinity levels often reaching 200mM NaCl. A research of salinity stress on Mahameru cultivar at 200 mM NaCl have not conducted yet. Therefore to conduct the research of Mahameru at high salinity stress to obtained high salinity tolerant soybean cultivar.   The observed variables are anatomy (epidermis thickness, the density of stomata and trichomes, palisade thickness) physiology (the dry weight of roots and canopy, the content of chlorophyll a and b) Production (whole pod, total filled pod, total empty pod, weight per one-hundred beans). The salinity treatment was 0, 50,100, 150, 200 mM NaCl given at three days before planting and twenty-one days after planting. The data of anatomy and physiology was taken at forty-five days after planting. The production data was taken when soybean plants turned brown. The result indicates that salinity affects anatomy characteristic of leaf, higher the salinity increasing epidermis thickness and the density of stomata and trichomes. Salinity affected the content of chlorophyll a and b. Higher the salinity increased the content of chlorophyll a and b. Salinity did not affect soybean production. Based on this study Mahameru cultivar is resistant to salinity up to 200 mM NaCl. The benefit of this research help to enhance national soybean production with utilization coastal land for soybean planting Mahameru cultivar.         

scholarly journals PRELIMINARY STUDY OF LARVAL DEVELOPMENT Oryzias javanicus IN INDONESIA

2017 ◽  
Vol 9 (1) ◽  
pp. 105
Author(s):  
Rachma Puspitasari ◽  
. Suratno
Keyword(s):  
High Salinity ◽  
Larval Fish ◽  
Coastal Region ◽  
Test Organism ◽  
Hatching Rate ◽  
Oryzias Javanicus ◽  
Test Organisms ◽  
Preliminary Study ◽  
Hatching Eggs ◽  
Selection Of

<p><em>Java medaka </em><em><span style="text-decoration: underline;">Oryzias</span> <span style="text-decoration: underline;">javanicus</span> potentially developed as test organism, represents the coastal region because it has a high adaptability in freshwater, brackishwater and marine environments. Utilization of it as a test organism has some obstacles such as lack of number of test organisms with same size or age. The fulfillment of number can be solved if the test organism is cultivated exclusively in the laboratory. This study was a preliminary study to get information about suitable salinity for spawning and hatching. Parameter observed were spawning ability in 0 and 20 ppt and hatching rate of egg among 0. 15 and 30 ppt and development of larval fish in 0 ppt. Result indicated that the fish was be able to spawn in 0 and 20 ppt. Eggs were hatched within 9 days in 30 ppt, faster than in freshwater and 15 ppt. In general, O. javanicus was be able to spawn either in freshwater or seawater, but there are differences in the behavior of fish in the laying of egg. Fish will carried their eggs in the abdomen in freshwater, while 20 ppt salinity fish tends to release the eggs. O. javanicus be able to live and lay eggs on freshwater and seawater. Selection of salinity is adjusted to test requirement in egg phase, pascalarva or adult. In general, breeding of fish easier and faster done in fresh water while hatching eggs take place more quickly in high salinity.</em></p><p><em><br /></em></p><p><strong><em>Keywords: </em></strong><em>Indonesia, Java Medaka, <span style="text-decoration: underline;">Oryzias</span> <span style="text-decoration: underline;">javanicus</span>, test organism</em><strong><em></em></strong></p>

Chlorophyll a biomass and growth of sea-ice microalgae along a salinity gradient (southeastern Hudson Bay, Canadian Arctic)

Polar Biology ◽  
1992 ◽  
Vol 12 (3-4) ◽  
Author(s):  
Louis Legendre ◽  
Marie-Jos�e Martineau ◽  
Jean-Claude Therriault ◽  
Serge Demers
Keyword(s):  
Sea Ice ◽  
Chlorophyll A ◽  
Salinity Gradient ◽  
Canadian Arctic ◽  
Hudson Bay

scholarly journals Seasonal hydrochemical variation in a tropical coastal lagoon (Açu Lagoon, Brazil)

2005 ◽  
Vol 65 (4) ◽  
pp. 597-607 ◽  
Author(s):  
G. G. Chagas ◽  
M. S. Suzuki
Keyword(s):  
Carbon Dioxide ◽  
Dissolved Oxygen ◽  
Chlorophyll A ◽  
Coastal Lagoon ◽  
Temporal Variations ◽  
Climatic Conditions ◽  
Total Alkalinity ◽  
Spatial And Temporal Variation ◽  
Phytoplankton Production ◽  
Spatial Gradient

Hydrochemical conditions in the Açu Lagoon are described using spatial and temporal variations of various limnological variables (water temperature, dissolved oxygen, electric conductivity, total alkalinity, carbon dioxide, dissolved and total nutrients (N, P and Si), and chlorophyll a). Collected data was used in order to understand the structure and functioning of an enclosed coastal lagoon strongly influenced by climatic conditions. Water samples were collected monthly (November 1999-December 2000) in five sampling stations established along the lagoon. A decreasing spatial gradient of electrical conductivity was observed beginning from a sand bar region between the lagoon and the sea in the direction of the sweet-water input area. The positive correlation observed between the pH and dissolved oxygen (DO) values, and the negative one observed between pH values and those of carbon dioxide (CO2), evidenced coupled biological processes, e.g., primary production and decomposition. Both spatial and temporal variation of dissolved nutrients showed fast increase and decrease in the beginning of summer, suggesting that nutrient input resulting from rainfall stimulates phytoplankton production, as reflected by chlorophyll a concentration increase.

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