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41 results for “Salinity gradient”
Repeat photography of tidal fresh forest trees along the salinity gradient of the Altamaha River, GA
We established a transect of 42 stations for repeat photography of tidal fresh forest trees along the salinity gradient of the Altamaha River estuary. Target trees are located approximately every km on both the north and south banks, beginning at km 20 (with 0 at the mouth of the estuary) up to km 41, for a total of 21 km. We used a small boat to travel to each station and take digital photographs of target trees facing the river in Nov 2017, Feb, May, Aug of 2018. In Oct 2018 we extended the transect an additional 5 km downstream so that it now starts at km 16, with 5 more stations on the north bank and 5 on the south bank. All 52 stations were photographed in Oct 2018 and Oct 2019. These photos will be used to distinguish healthy, stressed and dead trees in each image and how they change over time.
Figure 1 in Distribution of earthworm growth stages along a naturally occurring soil salinity gradient
Figure 1. (A) Field sampling location for earthworm and soil collections in southeast North Dakota, USA. (B) Five plots were established along a salinity gradient based on an electrical conductivity (EC1:1) survey. (C) Within each plot, five sub-plot locations were sampled. (D) Intact soil cores (20 cm in diameter, 15 cm deep) were hand-sorted for earthworms, which were counted and classified based on growth stage. Soils from each core were analyzed for physical and chemical soil properties.
Data from: Post‐glacial establishment of locally adapted fish populations over a steep salinity gradient
<p>Studies of colonization of new habitats that appear from rapidly changing environments are interesting and highly relevant to our understanding of divergence and speciation. Here, we analyse phenotypic and genetic variation involved in the successful establishment of a marine fish (sand goby, Pomatoschistus minutus) over a steep salinity drop from 35 PSU in the North Sea (NE Atlantic) to two PSU in the inner parts of the post-glacial Baltic Sea. We first show that populations are adapted to local salinity in a key reproductive trait, the proportion of motile sperm. Thereafter, we show that genome variation at 22,190 single nucleotide polymorphisms (SNPs) shows strong differentiation among populations along the gradient. Sequences containing outlier SNPs and transcriptome sequences, mapped to a draft genome, reveal associations with genes with relevant functions for adaptation in this environment but without overall evidence of functional enrichment. The many contigs involved suggest polygenic differentiation. We trace the origin of this differentiation using demographic modelling and find the most likely scenario is that at least part of the genetic differentiation is older than the Baltic Sea and is a result of isolation of two lineages prior to the current contact over the North Sea–Baltic Sea transition zone.</p>
Temporal and spatial changes in benthic invertebrate trophic networks along a salinity gradient
<p>Species interactions underlie all ecosystem goods and services and are important for understanding ecosystem changes. Representing one type of species interaction, trophic networks are able to be constructed from biodiversity monitoring data and known trophic links to understand how ecosystems have changed over time. The Baltic Sea is subject to high anthropogenic pressures, and its low species diversity makes it an ideal candidate for understanding how pressures change food webs. In this study, we used benthic monitoring data from 20 years (1980-1989 and 2010-2019) from the Swedish coast of the Baltic Sea and Skagerrak to investigate changes in benthic invertebrate trophic interactions. We constructed food webs and calculated traditional food web metrics that we compared over space and time. Our results show that the west coast of Sweden (Skagerrak) showed a reduction in benthic invertebrate biodiversity by 40% between the 1980's and 2010's, and that the number of links, linkage diversity, generality of predators, and vulnerability of prey have been significantly reduced. However, connectance has not significantly changed in the Skagerrak. The other basins (Bothnian Sea, Baltic Proper and Bornholm Basin) do not show any consistent significant trends in any food web metrics investigated, demonstrating resilience at a lower species diversity. The decreased complexity of the Skagerrak food webs indicates vulnerability to further perturbations and pressures should be limited as much as possible to ensure continued ecosystem functions.</p>
Fifteen physiological traits related to osmoregulation and reactive oxygen species metabolism in two life form aquatic plants under a natural water salinity gradient on the Tibetan Plateau and Northwest China
<p><span>Aquatic plants, as the primary producers, determine the community structure and ecological function of freshwater ecosystems. However, salinization threatens inland freshwater wetlands and thus the survival of aquatic plants. Exploring the plant physiological responses to increasing water salinity could enhance our understandings of plant adaptive strategies under future climate change regimes in wetlands. We measured 15 physiological traits of 49 aquatic plant species along a large environmental gradient in alpine and arid regions of western China, to explore the physiological adaptions and compare the similarities and differences in adaptive strategies between the two life forms to natural water salinity. We found that both water salinity and low temperature were key factors affecting aquatic plants in alpine and arid regions. Aquatic plants adapt to saline habitats by accumulating proline and sulfur (S) concentrations, and to cold habitats by increasing ascorbate peroxidase activity. Plant trait network analysis showed that the hub trait in emergent plants was S, but in submerged plants was proline, suggesting that emergent plants balanced osmoregulation and reactive oxygen metabolism via S-containing compounds, while submerged plants prioritizing the regulation of osmotic balance via proline.</span></p>
Evolutionary mismatch along salinity gradients in a Neotropical water strider
<p><span>The evolution of local adaptation is crucial for the <i>in situ</i> persistence of populations in changing environments. However, selection along broad environmental gradients could render local adaptation difficult, and might even result in maladaptation. We address this issue by quantifying fitness trade-offs (via common garden experiments) along a salinity gradient in two populations of the Neotropical water strider <i>Telmatometra withei </i>– a species found in both fresh (FW) and brackish (BW) water environments across Panama. We found evidence for local adaptation in the FW population in its home FW environment. However, the BW population showed only partial adaptation to the BW environment, with a high magnitude of maladaptation, along naturally-occurring salinity gradients. Indeed, its overall fitness was ~ 60% lower than that of the ancestral FW population in its home environment, highlighting the role of</span> phenotypic plasticity, rather than local adaptation, in high salinity environments<span>. This suggests that populations seemingly persisting in high salinity environments might in fact be maladapted, following drastic changes in salinity. Thus, variable selection imposed by salinization could result in evolutionary mismatch, where the fitness of a population is displaced from its optimal environment. Understanding the fitness consequences of persisting in fluctuating salinity environments is crucial to predict the persistence of populations facing increasing salinization. It will also help develop evolutionarily informed management strategies in the context of global change.</span></p>
Salt flat microbial diversity and population structure along a salinity gradient
<p>In this study, we examined the abundance of microbial communities in coastal sabkha and sabkha-shore regions in Abu Dhabi, UAE using 16s rDNA, and performed whole-genome metagenome analysis to elucidate the genetic heterogeneity of microbial species. Based on the 16s rDNA based prokaryotic microbial profile, we identified unusual coastal sabkha-specific microbial communities, consistent with the whole genome metagenome analysis. Out of 225 assembled microbial metagenomes, we analyzed 82 of the most abundant assembled genomes at the order and class taxonomic levels. We observed diversity was higher for some microbial populations on the inner regions of the sabkha as well as outside it, although the overall population diversity was higher within the sabkha. Our results show genetic structure over local spatial scales, different level of homologous recombination for different species as well as gene-specific selective sweeps. These results pave the way to understanding the ecological roles, salt stress tolerance mechanisms, and potential applications of sabkha microbial genes.</p>
Data supporting: Invader at the edge - genomic origins and physiological differences of round gobies across a steep urban salinity gradient
<p>Species invasions are a global problem of increasing concern, especially in highly connected aquatic environments. Despite this, salinity conditions can pose physiological barriers to their spread and understanding them is important for management. In Scandinavia's largest cargo port, the invasive round goby (Neogobius melanostomus), is established across a steep salinity gradient. We used 12 937 SNPs to identify the genetic origin and diversity of three sites along the salinity gradient and round goby from <span>western,</span> <span>central and </span>northern Baltic Sea, as well as north European rivers. Fish from two sites<span> from the extreme ends of the gradient</span> were also acclimated to freshwater and seawater, and tested for respiratory and osmoregulatory physiology. Fish from the high salinity environment in the outer port showed higher genetic diversity, and closer relatedness to the other regions, compared to fish from lower salinity upstream the river. Fish from the high salinity site also had higher maximum metabolic rate, fewer blood cells and lower blood Ca2+. Despite these genotypic and phenotypic differences, salinity acclimation affected fish from both sites in the same way: seawater increased the blood osmolality and Na+ levels, and freshwater increased the levels of the stress hormone cortisol. Our results show genotypic and phenotypic differences over short spatial scales across this steep salinity gradient. These patterns of the physiologically robust round goby are likely driven by multiple introductions into the high salinity site, and a process of sorting, likely based on behaviour or selection, along the gradient. Since this euryhaline fish risks spreading from this area, seascape genomics and phenotypic characterisation can inform management strategies even within an area as small as a coastal harbour inlet.</p>
Heat transport across the Antarctic Slope Front controlled by cross-slope salinity gradients
<p>Feb 2023 updates: </p> <ul> <li>Add code for EKE spectral analysis to MITgcm_ASF-heat-ver3/analysis/spectrum/</li> <li>Add products of 5km and 10km runs to products_new-ver3</li> <li>Add MITgcm source code, copied from <a href="http://mitgcm.org/">http://mitgcm.org</a></li> </ul> <p>This release contains updates on analysis code and products.</p> <ul> <li>MITgcm_ASF-heat-ver3/<strong>newexp</strong>/: the Matlab scripts used to generate and run the MITgcm simulations</li> <li>MITgcm_ASF-heat-ver3/<strong>analysis</strong>/<strong>cross_slope</strong>/ and MITgcm_ASF-heat-ver2/<strong>analysis</strong>/<strong>plots</strong>/: the Matlab scripts used to analyze model output and make plots.</li> <li>MITgcm_ASF-heat-ver3/analysis/<strong>spectrum</strong>/: the<strong> </strong>Matlab<strong> </strong>scripts to calculate EKE spectra<strong> </strong></li> <li>exps_configuration.zip: the configurations of the MITgcm simulations.</li> <li><strong>products_new-ver3.zip</strong>: the products calculated from MITgcm diagnostics, including 7-year means of all the model outputs, overturning streamfunctions, neutral density, shoreward heat transport, kinetic energy, temporal decomposition, isopycnal thickness fluxes of the 5km and 10km runs, etc. </li> <li>ThicknessFlux_FreshShelf.zip: products of isopycnal thickness flux, used to calculate the decomposition of eddy/tidal heat advection/diffusion, for the "fresh-shelf" simulation. </li> <li>ThicknessFlux_ref.zip: as above, but for the reference simulation.</li> <li>ThicknessFlux_DenseShelf.zip: as above, but for the "dense-shelf" simulation. </li> </ul> <p>The source code of the Massachusetts Institute of Technology General Circulation Model (MITgcm) is available at: <a href="http://mitgcm.org/">http://mitgcm.org</a>.</p> <p><strong>All the raw data of the model output are available at: <a href="https://doi.org/10.15144/S47P49">https://doi.org/10.15144/S47P49</a>.</strong></p> <p>To reproduce MITgcm_ASF simulations: </p> <ol> <li>Start each simulation with a 20-year spin-up integration. Before running each simulation, you need to substitute <em>&OBCS_PARM04</em> with <em>&OBCS_PARM05 </em>in the file <em>input/<strong>d</strong>ata.obcs</em>, and substitute <em>&EXF_NML_05 </em>with <em>&EXF_NML_OBCS</em> <em> </em>in the file <em>input/data.exf</em>. For simulations with very fresh shelf waters (e.g., shelf salinity = 33 psu), you need to spin up the simulation with a very small time step (e.g., 60s) for ~ two months, and then use a larger time step. </li> <li> <p>Initialize the production run from the corresponding spin-up run, using the Matlab script <em>initialize.m</em> in the folder<em> MITgcm_ASF-heat-ver2/newexp/. </em>When using the LAYERS package, you need to substitute<em> numperlist = 1</em> with <em>numperlist = 2 </em>in the file<em> code/DIAGNOSTICS_SIZE.h</em> before running the simulations.</p> </li> </ol> <p> </p> <p>Notes on calculationg the overturning streamfunction and its mean/eddy/tidal decomposition using the MITgcm LAYERS package: </p> <ul> <li>avg_t: Calculate time averages. It has been modified since the vertical number of layers can be different from Nr. </li> <li>calc_Overturning_pt, usscar_plot_overturning_pt: calculate and plot eddy/mean/isopycnal overturning streamfunction using potential temperature layer fluxes.</li> </ul> <ul> <li>calc_Overturning_rho, usscar_plot_overturning_rho: calculate and plot eddy/mean/isopycnal overturning streamfunction using potential density layer fluxes.</li> </ul> <ul> <li>calc_Overturning_pt_Aocean, usscar_pt_overturning_rho_Aocean (<strong>recommended if your bathymetry is not flat</strong>): calculate and plot eddy/mean/isopycnal overturning streamfunction using <em>potential temperature</em> layer fluxes. For each latitude, use the total ocean area below a certain level to interpolate the streamfunction from pt space to z space. </li> </ul> <ul> <li>calc_Overturning_rho_Aocean, usscar_plot_overturning_rho_Aocean (<strong>recommended <strong>if your bathymetry is not flat</strong></strong>): calculate and plot eddy/mean/isopycnal overturning streamfunction using <em>potential density</em> layer fluxes. For each latitude, use the total ocean area below a certain level to interpolate the streamfunction from potential density space to z space.</li> </ul> <ul> <li>calc_decomposition_OT, plot_OT_rho_Aocean_TidalEddyMean: decompose the isopycnal overturning streamfunction into <strong>tidal</strong>/eddy/mean components, using potential density layer fluxes.</li> </ul> <p>Feel free to contact Yidongfang Si via <strong>ysi@g.ucla.edu</strong> if you have any questions.</p>
Fifteen physiological traits related to osmoregulation and reactive oxygen species metabolism in two life form aquatic plants under a natural water salinity gradient on the Tibetan Plateau and Northwest China
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Transcriptome data: salinity adaptation in Rhithropanopeus harrisii across an estuarine gradient
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Data from: Assessing fish movement and physiological traits along a salinity gradient by measuring stable oxygen isotope values in fish blood water and muscle water
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Data supporting: Invader at the edge - genomic origins and physiological differences of round gobies across a steep urban salinity gradient
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Evolutionary mismatch along salinity gradients in a Neotropical water strider
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Temporal and spatial changes in benthic invertebrate trophic networks along a salinity gradient
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Data from: Post‐glacial establishment of locally adapted fish populations over a steep salinity gradient
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Data from: Body size and allometric shape variation in the molly Poecilia vivipara along a gradient of salinity and predation
Background: Phenotypic diversity among populations may result from divergent natural selection acting directly on traits or via correlated responses to changes in other traits. One of the most frequent patterns of correlated response is the proportional change in the dimensions of anatomical traits associated with changes in growth or absolute size, known as allometry. Livebearing fishes subject to predation gradients have been shown to repeatedly evolve larger caudal peduncles and smaller cranial regions under high predation regimes. Poecilia vivipara is a livebearing fish commonly found in coastal lagoons in the north of the state of Rio de Janeiro, Brazil. Similar to what is observed in other predation gradients, lagoons inhabited by P. vivipara vary in the presence of piscivorous fishes; contrary to other poeciliid systems, populations of P. vivipara vary greatly in body size, which opens the possibility of strong allometric effects on shape variation. Here we investigated body shape diversification among six populations of P. vivipara along a predation gradient and its relationship with allometric trajectories within and among populations.ResultsWe found substantial body size variation and correlated shape changes among populations. Multivariate regression analysis showed that size variation among populations accounted for 66% of shape variation in females and 38% in males, suggesting that size is the most important dimension underlying shape variation among populations of P. vivipara in this system. Changes in the relative sizes of the caudal peduncle and cranial regions were only partly in line with predictions from divergent natural selection associated with predation regime.ConclusionsOur results suggest the possibility that adaptive shape variation among populations has been partly constrained by allometry in P. vivipara. Processes governing body size changes are therefore important in the diversification of this species. We conclude that in species characterized by substantial among-population differences in body size, ignoring allometric effects when investigating divergent natural selection?s role in phenotypic diversification might not be warranted.
Data from: Fish and tetrapod communities across a marine to brackish salinity gradient in the Pennsylvanian (early Moscovian) Minto Formation of New Brunswick, Canada, and their palaeoecological and palaeogeographical implications
Euryhaline adaptations in Pennsylvanian vertebrates allowed them to inhabit the marine to freshwater spectrum. This is illustrated by new assemblages of fish and tetrapods from the early Moscovian Minto Formation of New Brunswick, Canada. Fish include chondrichthyans (xenacanthids and the enigmatic Ageleodus), acanthodians (gyracanthids and acanthodiforms), sarcopterygians (rhizodontids, megalichthyids and dipnoans), and actinopterygians (eurynotiforms). Tetrapods include small- to medium-sized, and largely aquatic, stem tetrapods (colosteids) and anthracosaurs (embolomeres). A key finding is that the parautochthonous fossil assemblages are preserved across a salinity gradient, with diversity (measured by the Simpson Index) declining from open marine environments, through brackish embayments, and reaching a nadir in tidal estuaries. Chondrichthyans dominate the entire salinity spectrum (65% of fossils), a distribution that demonstrates a euryhaline mode of life, and one large predatory chondrichthyan, Orthacanthus, may have practised filial cannibalism in coastal nurseries because its heteropolar coprolites contain juvenile xenacanthid teeth. In contrast, other fish communities were more common in open marine settings while tetrapods were more common in coastal brackish waters. While all these faunas were also likely to have been euryhaline, their osmoregulation was, perhaps, less versatile. The demonstration of widespread euryhalinity among fish and aquatic tetrapods explains why Pennsylvanian faunas generally show a cosmopolitan biogeography because taxa were able to disperse via seaways. It also resolves the paradox of enriched strontium isotopic signatures observed in these faunas because organisms would have been, at times, exposed to continental water bodies as well. Therefore, our new findings contribute to the long-running debate about the ecology of Pennsylvanian fishes and tetrapods.
Figure 6 in Mollusk distribution in four habitats along a salinity gradient in a coastal lagoon from the Gulf of Mexico
Figure 6. PCA plot showing relationships between environmental variables and molluscan assemblages from Mecoacan lagoon. Numbers represent sites, black dots = cold fronts season, open triangles = drought season, and black squares = rainy season. Sal: salinity; OD: dissolved oxygen; TDS: turbidity; Temp: temperature.
Figure 4 in Mollusk distribution in four habitats along a salinity gradient in a coastal lagoon from the Gulf of Mexico
Figure 4. MDS plot of bootstrap averages showing variations of molluscan assemblages by habitat. Ellipses denote approximate 95% confidence intervals and black symbols represent averages (av).
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Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
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DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
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The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
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