Wide Range Of Salinities Research Articles

Increased salinity decreases annual gross primary productivity at a Northern California brackish tidal marsh

Tidal marshes sequester 11.4–87.0 Tg C yr−1 globally, but climate change impacts can threaten the carbon capture potential of these ecosystems. Tidal marshes occur across a wide range of salinity, with brackish marshes (0.5–18 ppt (parts per thousand)) dominating global tidal marsh extents. A diverse mix of freshwater- and saltwater-tolerant plant and microbial communities has led researchers to predict that carbon cycling in brackish wetlands may be less sensitive to changes in salinity than fresh- or saltwater wetlands. Rush Ranch, a well-monitored brackish tidal wetland of the San Francisco Bay National Estuarine Research Reserve, experiences highly variable annual salinity regimes. Within a five-year period (2014–2018), Rush Ranch experienced particularly extreme drought-induced salinization during the 2014 and 2015 growing seasons. During drought years, tidal channel salinity rose from a 15 year baseline of 4.7 ppt to growing season peaks of 10.3 ppt and 12.5 ppt. Continuous eddy covariance data from 2014 to 2018 demonstrate that during drought summers, gross primary productivity (GPP) decreased by 24%, whereas ecosystem respiration remained similar among all five years. Stepwise linear regression revealed that salinity, not air temperature or tidal height, was the dominant driver of annual GPP. A random forest model trained to predict GPP based on environmental data from low salinity years (i.e. naive to salinization) significantly over predicted GPP in drought years. When growing season salinities were doubled, annual estimates of net ecosystem exchange of CO2 decreased by up to 30%. These results provide ecosystem-scale evidence that increased salinity influences CO2 fluxes dominantly through reductions in GPP. This relationship provides a starting point for incorporating the effect of changes in salinity in wetland carbon models, which could improve wetland carbon forecasting and management for climate resilience.

Comparative Energetics of Various Membrane Distillation Configurations and Guidelines for Design and Operation

This paper presents a comparative performance study of single-stage desalination processes with major configurations of membrane distillation (MD) modules. MD modules covered in this study are (a) direct contact MD (DCMD), (b) vacuum MD (VMD), (c) sweeping gas MD (SGMD), and (d) air gap MD (AGMD). MD-based desalination processes are simulated with rigorous theoretical MD models supported by molecular thermodynamic property models for the accurate calculation of performance metrics. The performance metrics considered in MD systems are permeate flux and energy efficiency, i.e., gained output ratio (GOR). A general criterion is established to determine the critical length of these four MDs (at fixed width) for the feasible operation of desalination in a wide range of feed salinities. The length of DCMD and VMD is restricted by the feed salinity and permeate flux, respectively, while relatively large AGMD and SGMD are allowed. The sensitivity of GOR flux with respect to permeate conditions is investigated for different MD configurations. AGMD outperforms other configurations in terms of energy efficiency, while VMD reveals the highest permeate production. With larger MD modules, utilization of thermal energy supplied by the hot feed for evaporation is in the order of VMD > AGMD > SGMD > DCMD. Simulation results highlight that energy efficiency of the overall desalination process relies on the efficient recovery of spent for evaporation, suggesting potential improvement in energy efficiency for VMD-based desalination.

Effects of salinity on anoxic–oxic system performance, microbial community dynamics and co-occurrence network during treating wastewater

Salinity is one of the great challenges in the biological treatment of high-salinity wastewater. Unraveling how microbial associations respond to salinity stress and how they affect ecosystem function and community stability are crucial for wastewater treatment. However, little is known about the relationships among microorganisms under salinity stress. Hence, an anoxic–oxic (A/O) reactor was adopted to investigate the effects of elevated salinity (20 g/L-60 g/L) on system performance, microbial community dynamics and co-occurrence network during treating urine wastewater. The results indicated that the reactor achieved over 90% removal of both urea and COD in a wide range of salinity. Microbial alpha diversity decreased with increased salinity, as well as beta diversity also significantly changed. Elevated salinity led to a greater proportion of negative correlations in both anoxic and oxic microbial co-occurrence networks, which acted as a survival strategy for microorganisms under high-salinity stress. Clostridiales and Oceanospirillales were the keystones and played important roles in maintaining system stability. Furthermore, the oxic communities were more stable than the anoxic communities under salinity stress. These findings offered new sights for understanding microbial relationships in response to salinity in anoxic and oxic systems, and also provided a reference basis for treating high-salinity wastewater efficiently.

Physiological and morphological responses of ‘Irukandji’ polyps to thermal and osmotic conditions: consequences for niche profiling

The Irukandji jellyfish (Carukia barnesi) is a medically important species. While the medusa stage of this species is well known, due to its highly venomous sting, the benthic polyp has core roles in regulating both the timing and abundance of medusa making it a research priority. However, due to their small size, Carukia barnesi polyps have never been found in situ and, basic ecological knowledge surrounding this life stage is limited. In this study we adopt a lab-based approach, utilizing physiological tolerance as a functional tool, to gain new insights into the in situ location for Carukia barnesi polyps. The physiological tolerance of Carukia barnesi polyps was characterized by measuring the oxygen consumption rates of polyps exposed to different salinity/temperature combinations. A total of nine salinities and seven temperatures were investigated, ranging from 11 °C/16‰ to 34 °C/42.5‰, encompassing the spectrum of environments experienced on the Great Barrier Reef. Polyps were also monitored for morphological changes such as asexual reproduction, polyp deterioration, and mortality. Salinity did not have a significant effect on oxygen consumption rates, with Carukia barnesi polyps displaying a significant tolerance to a wide range of salinities. The effect of temperature, however, was statistically significant with oxygen °consumption rates increasing alongside water temperature. There was no statistical evidence to support an interactive effect between salinity and temperature. Based on these results, we conclude that the polyp stage of this species is likely located in an environment with stable temperatures and fluctuating salinities and, consequently, future endeavors aimed at locating this life stage should expand targeted survey areas outside stable oceanic environments, typical of medusa, and encompass dynamic environments such as estuaries and submarine freshwater upwellings.

Transcriptome, Proteome, Histology, and Biochemistry Analysis of Oriental River Prawn Macrobrachium nipponense under Long-term Salinity Exposure

Salinity is an ecological factor affecting the physiology, survival, and distribution of crustaceans. Additionally, salinity fluctuation detrimentally affects the composition and biological process of crustaceans. As a significant commercial aquaculture species in China, Japan, and Southeast Asian countries, the oriental river prawn, Macrobrachium nipponense, can tolerate a wide range of salinity. The transcriptome, proteome, histology, and physiology analysis were utilized to explore the physiological responses and molecular mechanisms of salinity tolerance in M. nipponense. Through the three-month culture, the statistic of growth trait illustrated the relatively excellent performance of M. nipponense in low salinity, and the higher salinity exposure significantly affected the growth of M. nipponense. In terms of the histological analysis, the gills and hepatopancreas of M. nipponense suffered varying degrees of damage. Besides, the activities of the digestive, immune-related, and metabolic enzymes were calculated. These results indicated that salinity significantly influenced trypsin and amylase in hepatopancreas, especially in 14 ppt. The immune-related enzymes were activated in high salinity. Notably, the activity of metabolic enzymes was significantly low in 7 and 14 ppt, which testified that the 7 ppt to 14 ppt were near the isotonic point of M. nipponense. In gills, hepatopancreas, and muscle, high-throughput mRNA sequencing revealed 11356, 2227, and 1819 differentially expressed genes (DEGs) by comparing the 7, 14, and 21 ppt groups with the 0ppt group, respectively. The TMT-labeling proteome identified 439 and 230 differentially expressed proteins (DEPs) in gills and hepatopancreas through the comparison of the 7, 14, and 21 ppt groups to the 0 ppt group, respectively. Additionally, through the integration of transcriptome and proteome, several pathways related to salinity adaptation were enriched, including protein export, cGMP-PKG signaling pathway, Amino sugar and nucleotide sugar metabolism, and Glycine, serine and threonine metabolism. Besides, 16 up and down-regulated proteins and related DEGs were detected through KEGG enrichment analysis, including ETHE1, BIP, chitinase (E3.2.1.14), and SARDH. Notably, no significantly regulated proteins and related DEGs were recorded by the correlation of transcriptome and proteome of 0 ppt and 7 ppt in hepatopancreas. Thus, the optimum survival salinity of M. nipponense may range from 0 ppt to 7 ppt. Overall, these results may provide valuable insights into the mechanisms underlying the culture of M. nipponense in different salinity.

Performa pertumbuhan udang vaname (Litopenaus vannamei) Pada Salinitas berbeda

ABSTRACT
 Vannamei shrimp is one type of the Penaeid shrimp group that is able to adapt to high salinity waters of up to 50 g L-1 and also from freshwater waters, especially in juvenile to adult stages (Pan et al. 2007). Vannamei shrimp are included in the category of euryhalin organisms so that they can survive differently, this is in accordance with (Daviss, 2004). Vannamei shrimp have the ability to survive in a wide range of water salinity so that technology development for aquaculture environmental engineering can be carried out in conditions of water salinity that are quite diverse. The high tolerance ability of vaname shrimp to a wide range of salinity values is one of the triggers for increased activity of vaname shrimp farming, especially in some Asia (Shinn et al. 2018; FAO 2018). This study used a completely randomized design (CRD) with 4 treatments with three replications each. As for what was tested for treatment A (25 ppt salinity), B (20 ppt salinity), C (15 ppt salinity), D (10 ppt salinity). The results of different salinity studies showed a significant effect (P

Simultaneous electricity generation and steam production from a wide range of salinity by using unique nanofluidic diode

Hygroelectric generator shows the advantages of sustainability, stability and low cost, and has attracted widespread attention in recent years. However, current power generators based on hydrovoltaic effect are limited to exploiting deionized (DI) water or low ion concentrations, which severely restricts their practical applications. Herein, we report a device concept that can break the solution salinity limit to generate electricity and produce clean water vapor at the same time, which cannot be achieved by any existing hygroelectric technology. Such multifunctional generator design is based on the synergistic effect between nanofluidic diode governed ionic transport and REDOX reaction, which guarantees the sustained power generation in a wide range of ion concentrations over 8 orders of magnitude. Except for harvesting energy from a dynamically changing aqueous solution, the power output can be further augmented by introducing photo-thermal response and reducing heat loss. Under one sunlight irradiation, the device achieves a power density output of 122.21 μW cm−2 in 2 M NaCl solution. While generating electricity, the device allows solar-enabled steam generation and gives rise to an additional steam of 3.23 kg m−2 h−1. These results represent a new breakthrough in improving the operational reliability, power output and versatility of hygroelectric generators in dynamic salinity environments.

Bioinspired photothermal polyaniline composite polyurethane sponge: Interlayer engineering for high-concentration seawater desalination

Interfacial solar evaporation has attracted substantial research interest as an eco-friendly means of desalination. A great deal of work has been devoted to exploring broad-spectrum solar absorbers, porous floating systems, and appropriate thermal insulations. During desalination, salt accumulation may block the evaporation channel and severely decline the evaporation rate. Herein, we designed a salt-resistant solar evaporator (PANI-SPPSU@PU) based on a polyurethane sponge (PU) with the polyaniline (PANI) photothermal layer and a negatively charged sulfonated polyphenylsulfone (SPPSU) interlayer. The negatively charged interlayer appends an energy barrier, which reduces the amount of the salt ions diffusing into the interlayer and regulates the local salt concentration. By this negatively charged structure, the solar evaporator enables stable evaporation from a wide range of salinity (even saturation concentration), and achieves a high evaporation rate above 1.91 kg/m2 h in 10 wt% NaCl (at the state of the art). A promising salt-resistant mechanism via the synergy of the diffusion effect and the Donnan effect is also proposed in this work. Therefore, it provides a promising pathway for practical solar-powered high-salinity seawater desalination.

Multi-Year Environmental Trends of Shrimp Black Gill (Hyalophysa lynni) Prevalence in Texas Gulf Coast Shrimp Populations

Shrimp Black Gill, caused by the apostome ciliate Hyalophysa lynni, is an emerging disease impacting penaeid shrimp populations along the southeast Atlantic Coast and the Gulf of Mexico (GOM). Changing annual environmental conditions may drive infection levels of this parasitic ciliate in these populations, which comprise one of the largest fisheries in the United States. Hyalophysa lynni is established on the Texas Gulf Coast, and prevalence of this parasite has a strong seasonal and spatial trend, likely linked with high temperature and a wide range of estuarine salinities. Texas Parks and Wildlife Department monitored shrimp black gill in 2 penaeid shrimp species, Litopenaeus setiferus and Farfantepenaeus aztecus in 2019, with the aim of observing trends in prevalence along spatial and temporal scales. Hyalophysa lynni was found in all 7 bay systems throughout the study period, and this study is a continuation of that monitoring effort, adding 2 years of data collection (2020 and 2021) to prior research. Throughout the entire sampling period (2019–2021) and coastwide, H. lynni was found in 66% of all shrimp samples collected, although prevalence varied annually. Boosted regression tree modeling indicated that low salinity, high temperature, and time of year (late spring through fall) had a significant relationship with H. lynni prevalence in shrimp along the Texas Gulf Coast. Shrimp Black Gill is likely to continue to be present in GOM shrimp populations, and annual precipitation events and increased water temperatures may amplify the population morbidity within any given year.

An electromembrane microextraction-based green method for the determination of trace copper in natural waters.

Driven by the search for an environmentally-friendly methodology, electromembrane extraction (EME) has recently emerged as a green and versatile tool for the analysis of trace pollutants in water samples, being mainly applied to the preconcentration and determination of organic compounds. Recently, EME has also shown its applicability to the analysis of inorganic species, allowing a considerable reduction in both reagent consumption and extraction times, and without loss of efficacy, in comparison with other liquid phase microextraction techniques. In this study, an EME system for trace copper analysis in natural waters has been optimised by the modified simplex method. A chemical modifier, di-2-pyridyl ketone benzoylhydrazone (dPKBH) was synthesized and dissolved in 1-nonanol, to be used as an organic phase impregnated into the pores of a polymeric hollow fibre. With only 15 min of extraction, an enrichment factor of 77.1 ± 10.8 was obtained for a wide salinity range (0-35), allowing its application in a variety of different waters, including seawater. Optimum operating conditions were a sample pH of 6.26, an electric potential of 95 V, 0.08 M nitric acid as the acceptor phase, 4.01 mM dPKBH in 1-nonanol as the organic phase and a stirring rate of 1500 rpm. A LOD of 0.004 μg L-1 was obtained, and the system was successfully applied to the analysis of several water samples containing copper at low ppb levels (tap water and river water) or even at sub-ppb levels (seawater).

Responses to salinity in the littoral earthworm genus Pontodrilus

The cosmopolitan littoral earthworm Pontodrilus litoralis is distributed in tropical and sub-tropical coastal habitats, whereas P. longissimus is reported only in the Thai-Malay coastal line. In the present study, we examined the difference in salinity effect on the survival rate, wet weight (hereafter weight) change, behaviour, and osmolality of these two Pontodrilus species. A 28 d exposure to varying salinity concentration (0–50 ppt) revealed that P. litoralis is able to survive over a wide salinity range than P. longissimus, with the latter species exhibiting a low survival rate over the same salinity range. During short-term exposure (0–96 h) to a salinity of less than 30 ppt, P. litoralis exhibited weight gain and this was significant in the first 12 h of exposure. However, P. longissimus gained weight when exposed to salinity at under 10 ppt in the first 72 h of exposure. The two species of Pontodrilus behaved differently when exposed to different salinities. The coelomic fluid osmolarity of Pontodrilus was related to the exposure medium and was mostly maintained as hyperosmotic to the external medium over the range of salinities tested. This study shows how two different species of the littoral earthworm genus Pontodrilus respond to a change in salinity, which may explain their dispersal pattern and shape their distribution pattern throughout Southeast Asia.

Algorithm for estimating boundary conditions of a distributed tracer for application in a single-well tracer test

An important tool in determining residual oil saturation today is the single-well tracer test, as the preferred method for assessing the potential for using enhanced oil recovery methods (EOR) and developing pilot projects. The success of the test performed directly depends on the optimal choice of the tracer composition, which will contribute to the qualitative determination of the parameters required in the calculation of the residual oil saturation of the formation. To assess the boundary conditions for the applicability of the tracer in the field, the kinetic and thermodynamic properties of tracers are considered under various reservoir conditions of the field. Based on the results of this work, an algorithm for assessing the applicability of the tracer for reservoirs in a wide range of salinity and temperatures is presented.

Toward low-salinity waterflooding predictive capability development in carbonates for fast screening of oil-brine-rock candidates

Despite numerous studies on the low-salinity waterflooding (LSWF) technique, a robust predictive capability has not yet been established. Predictive capability development is essential to reduce costs and time during the early screening or prioritization of candidate fields for LSWF in the opportunity realization process (ORP). This study aims at proposing a set of screening methods that offer the best LSWF predictive capability for various crude oil-brine-carbonate rock systems. In this regard, the robustness of different methods for predicting oil recovery factor (RF) from core-scale spontaneous imbibition (SI) experiments in carbonate rocks was investigated here. The relevant small-scale screening methods were divided into two distinct categories. The first category includes methods based on rock/fluid interactions: wettability assessment based on flotation and contact angle measurement, and geochemical assessment to identify mineral dissolution (and pH change). The second group includes methods based on probing fluid/fluid interactions: oil-brine interfacial tension (IFT) and viscoelasticity, and micro-dispersion formation. The most common types of carbonate rocks, including dolomite, limestone, and chalk, were used to comprehensively evaluate the response of each carbonate rock type to brines of different salinities. Each rock type could be distinguished with its particular microscopic texture, pore-size, grain type, and carbonate mineral structure. According to the SI results, oil recovery strongly depends not only on brine salinity but also on the rock type. The oil RF for Indiana limestone was found to be higher than that for other rock types but showed less sensitivity to the degree of dilution. Additionally, RF from dolomite and chalk plugs showed the most and the least sensitivity to the degree of brine dilution, respectively. We introduced a brine efficiency index based on the SI results to compare the results for different rock types and salinities. The results of the systematic tests performed here showed that variation of IFT and viscoelasticity (expressed as phase angle) with brine salinity reduction was neither significant nor monotonic, and did not correlate with the brine efficiency index. Also, minor/negligible mineral dissolution was observed upon brine-rock contact. On the other hand, wettability results based on contact angle measurement and flotation, as well as microdispersion results strongly correlated with the brine efficiency index over a wide range of brine salinities, which indicates these techniques can quickly predict the potency of a system toward low salinity effect (LSE). It is hypothesized, therefore, that the techniques which involve rock explicitly would be more robust because they capture the rock-type dependency of LSE too. The findings from this study can be used for quick screening of the candidate formations for LSWF, before performing the costly and time-intensive special core analysis (SCAL) experiments. The data provided by this research can also enrich the SCAL data bank toward developing robust data-driven predictive models.

In situ bioremediation of petroleum hydrocarbon-contaminated soil: isolation and application of a Rhodococcus strain.

Due to low consumption and high efficiency, in situ microbial remediation of petroleum hydrocarbons (PHs)-contaminated sites in in-service petrochemical enterprises has attracted more and more attention. In this study, a degrading strain was isolated from oil depot-contaminated soil with soil extract (PHs) as the sole carbon source, identified and named Rhodococcus sp. OBD-3. Strain OBD-3 exhibited wide adaptability and degradability over a wide range of temperatures (15-37°C), pH (6.0-9.0), and salinities (1-7% NaCl) to degrade 60.6-86.6% of PHs. Under extreme conditions (15°C and 3-7% salinity), PHs were degraded by 60.6 ± 8.2% and more than 82.1% respectively. In OBD-3, the alkane monooxygenase genes alkB1 and alkB2 (GenBank accession numbers: MZ688386 and MZ688387) were found, which belonged to Rhodococcus by sequence alignment. Moreover, strain OBD-3 was used in lab scale remediation in which the contaminated soil with OBD-3 was isolated as the remediation object. The PHs were removed at 2,809 ± 597mg/kg within 2months, and the relative abundances of Sphingobium and Pseudomonas in soil increased more than fivefold. This study not only established a system for the isolation and identification of indigenous degrading strains that could efficiently degrade pollutants in the isolated environment but also enabled the isolated degrading strains to have potential application prospects in the in situ bioremediation of PHs-contaminated soils.

Interaction between Hydrated Smectite Clay Particles as a Function of Salinity (0-1 M) and Counterion Type (Na, K, Ca).

Swelling clay minerals control the hydrologic and mechanical properties of many soils, sediments, and sedimentary rocks. This important and well-known phenomenon remains challenging to predict because it emerges from complex multiscale couplings between aqueous chemistry and colloidal interaction mechanics in nanoporous clay assemblages, for which predictive models remain elusive. In particular, the predominant theory of colloidal interactions across fluid films, the widely used Derjaguin-Landau-Verwey-Overbeek model, fails to predict the ubiquitous existence of stable swelling states at interparticle distances below 3 nm that are stabilized by specific inter-atomic interactions in overlapping electrical double layers between the charged clay surfaces. Atomistic simulations have the potential to generate detailed insights into the mechanisms of these interactions. Recently, we developed a metadynamics-based molecular dynamics simulation methodology that can predict the free energy of interaction between parallel smectite clay particles in a wide range of interparticle distances (from 0.3 to 3 nm) and salinities (from 0.0 to 1.0 M NaCl). Here, we extend this work by characterizing the sensitivity of interparticle interactions to counterion type (Na, K, Ca). We establish a detailed picture of the free energy of interaction of parallel clay particles across water films as the sum of five interaction mechanisms with different sensitivities to salinity, counterion type, and interparticle distance.

A near infra-red emitting supramolecular dye-polymer assembly as promising platform for protamine sensing

Detection and quantification of bioanalytes using near infra-red (NIR) probes provide several advantages, viz, negligible scattering of light, minimum interference from the background matrices, deep sample penetration, etc. Herein, we report a supramolecular dye-polymer complex, comprising of mono-cationic LDS-798 dye and multi-anionic polystyrene sulfonate (PSS), as a promising NIR emitting turn-on probe for protamine (Pr) sensing. The supramolecular complex displays moderate fluorescence enhancement for LDS-798 due to its binding onto PSS surface. Strikingly, in the presence of Pr, this complex displays further enhancement in its emission intensity, which is also substantiated by a significant increase in the excited-state lifetime of LDS-798 dye. This turn-on response is found to be highly selective towards Pr, which is attributed to the structural change taking place for the anionic PSS on its interaction with highly cationic Pr molecule. Such a conformational change creates several cavities into the modified PSS structure, which can suitably encapsulate LDS-798 dye via strong hydrophobic interaction. Accordingly, there is large decrease in the radiationless decay processes for the excited dye molecules, making them strongly emissive in nature. Furthermore, LDS-798−PSS complex is found to be quite robust against changing temperature and ionic strength of the medium, indicating its possible use as a fluorescent probe over a wide range of temperature and salinity.

Multi‐Control of Ion Transport in a Field‐Effect Iontronic Device based on Sandwich‐Structured Nanochannels

AbstractBiomimetic smart nanochannels can regulate ion transport behavior responsive to the external stimuli, having huge potential in nanofluidic devices, sensors and energy conversion. Field‐effect nanofluidic diodes or transistors based on electric‐responsive nanochannels are emerging owing to their advantages such as non‐invasiveness, in situ, real time, and high efficiency. However, simultaneously realizing the voltage‐control of the ion conductance and ion current rectification (ICR) properties is still a big challenge. Here, a field‐effect iontronic device is developed based on ionomer/anodic aluminum oxide/conducting polymer sandwich‐structured nanochannel to realize the multi‐control of ion transport behaviors including ion conductance, ICR magnitude, and ICR direction by modulating the surface charge, wettability, and morphology of the nanochannel. The electroactive conducting polymer carries tunable surface charges responsive to the electric stimuli, leading to the regulation of ICR values. The complex three‐segment structures lead to the reverse of ICR direction by reconfiguring the charge distribution along with the whole channel. The switching wettability between hydrophilic and hydrophobic results in the regulation of ion conductance. Furthermore, the field‐effect iontronic device functions in a wide salinity range especially in hypersaline environment, due to the salinity‐adaptive properties of the membrane. A new route is provided for designing more functional field‐effect nanofluidic devices.

CAGE-ARCLIM cruise: Culturing (sub)Arctic planktic foraminifera Neogloboquadrina pachyderma and Globigerina bulloides: Implications for ocean acidification and paleoceanography reconstructions

From the morning of June 23rd to the morning of June 30th 2022, the Department of Geosciences at UiT the Arctic University of Norway, arranged a scientific cruise on R/V “Helmer Hanssen aimed at sampling living planktic foraminifera (Neogloboquadrina pachyderma and Globigerina bulloides) for culturing experiments both onboard and continued at the culturing laboratory at the Department. The purpose is to investigate the physiological and calcification responses of this species to a wide range of temperature, salinity and carbonate chemistry as well as to establish Arctic-tailored proxy calibrations for paleoceanography reconstructions

Isolation and Characterization of a Novel Vibrio natriegens—Infecting Phage and Its Potential Therapeutic Application in Abalone Aquaculture

Phage-based pathogen control (i.e., phage therapy) has received increasing scientific attention to reduce and prevent the emergence, transmission, and detrimental effects of antibiotic resistance. In the current study, multidrug-resistant Vibrio natriegens strain AbY-1805 was isolated and tentatively identified as a pathogen causing the death of juvenile Pacific abalones (Haliotis discus hannai Ino). In order to apply phage therapy, instead of antibiotics, to treat and control V. natriegens infections in marine aquaculture environments, a lytic phage, vB_VnaS-L3, was isolated. It could effectively infect V. natriegens AbY-1805 with a short latent period (40 min) and high burst size (~890 PFU/cell). Treatment with vB_VnaS-L3 significantly reduced the mortality of juvenile abalones and maintained abalone feeding capacity over a 40-day V. natriegens challenge experiment. Comparative genomic and phylogenetic analyses suggested that vB_VnaS-L3 was a novel marine Siphoviridae-family phage. Furthermore, vB_VnaS-L3 had a narrow host range, possibly specific to the pathogenic V. natriegens strains. It also exhibited viability at a wide range of pH, temperature, and salinity. The short latent period, large burst size, high host specificity, and broad environmental adaptation suggest that phage vB_VnaS-L3 could potentially be developed as an alternative antimicrobial for the control and prevention of marine animal infections caused by pathogenic V. natriegens.

Effects of salinity on survival, reproductive performance, population growth, and life stage composition in the calanoid copepod Acartia bilobata

Copepods are a critical live prey item for most marine finfish larvae in the natural environment. The calanoid copepod belonging to species Acartia is a potential live food for the larval rearing of marine finfishes because of their higher productivity and tolerance to wide range of salinities. The present study was conducted to determine the effect of salinity on production parameters to standardize the optimal salinity for Acartia bilobata culture. For selecting the optimal salinity range, the adult copepods were exposed to abrupt salinity change from 30 g L−1 to ten salinity levels, including 0, 5, 10, 15, 20, 25, 30, 35, 40 and 45 g L−1 and their survival estimated after 24 h. Further, the effect of salinity (15, 20,25,30, and 35 g L−1) on egg production, hatching success and population growth were studied. Following sudden salinity change, A. bilobata could tolerate a wide range of salinities from 15 to 35 g L−1, and no copepod survived below 10 g L−1 and above 35 g L−1. Average daily egg production was significantly higher at 25 and 30 g L−1 (32 ± 1 and 34 ± 2 eggs female−1 day−1). A remarkably low egg hatching success was recorded at 15 g L−1 salinity; however, all other tested salinities showed similar egg hatching success. Different salinity levels did not affect the sex ratio of A. bilobata. A significantly higher total population number (1539 ± 75) and intrinsic population growth rate (0.50 ± 0.00) was observed at 30 g L−1, followed by 25 g L−1 salinity. The lowest mean population (518 ± 19) and population growth rate (0.39 ± 0.00) were recorded at 15 g L−1 salinity. The study results suggested that 25–30 g L−1 is the optimal salinity range to achieve maximal production of A. bilobata.