Live Brine Research Articles

Evaluating the Effect of Live Brine Shrimp (Artemia franciscana) on Growth Performance in Ornamental Fish, Cyprinus rubrofuscus (Lacepede, 1803)

Feeding is a critical factor for both cultured and ornamental fish species. This study aimed to evaluate the effects of live brine shrimp (Artemia franciscana) on the growth and biochemical composition of fish. In the present study, sixty days feeding trail was conducted on the growth performance of ornamental fish, koi carp (Cyprinus rubrofuscus). The type of food such as live feed, nutrient-enriched prepared feed and commercial feed exerted a significant impact on the growth and body composition of fish. The specific growth rate is high in live brine shrimp fed fishes followed by prepared food. After 60 days experiment showed that the maximum length and weight of live brine shrimp fed fishes were 7.5 ± 0.9 cm and 5.3 ± 1.7 gm, respectively. The survival rates of the fish were 100 % under all feeding groups. The biochemical profiles of the fish varied significantly between the different feeding regimes. These results suggest that live feed is more effective than pelletized feed for ornamental fish culture.

Survival and growth of larval Pallid Sturgeon are improved by a live diet

AbstractObjectiveConservation propagation facilities in the upper basin of the Missouri River are currently experiencing inconsistent survival of first‐feeding larval Pallid Sturgeon Scaphirhynchus albus among genetic families (i.e., distinct male–female pairings). The inconsistent survival can have unintended negative consequences for genetic representation of Pallid Sturgeon that are returned to the Missouri and Yellowstone rivers. We conducted a laboratory study designed to determine whether a live diet improves survival and growth of first‐feeding larval Pallid Sturgeon.MethodsFirst‐feeding larval Pallid Sturgeon from three distinct genetic families were assigned to one of the following diets: live first instar brine shrimp (Artemia franciscana) nauplii, an Otohime dry diet, a 50–50% combination of Otohime and live first instar brine shrimp nauplii, or food restricted (no food). Mortality was evaluated at the end of each day and at the end of the trial (21 days after the onset of exogenous feeding), and individual weight (g) was measured at the end of the trial.ResultPallid Sturgeon larvae that received a live diet (either solely live first instar brine shrimp nauplii or the combined diet) experienced higher survival than larvae that were fed solely Otohime. Furthermore, there was statistical evidence that larvae receiving solely live first instar brine shrimp nauplii were heavier at 21 days postexogenous feeding than larvae that were fed either solely Otohime or the combined diet.ConclusionOur results suggest that a live diet can improve survival and growth of first‐feeding larval Pallid Sturgeon at conservation propagation facilities.

Effect of Predisolved Natural Gas on CO2 Solubility in Water With Various Salinities at Reservoir Conditions

Dissolution of CO2 in saline waters is considered one of three main CO2 trapping mechanisms, along with structural/stratigraphic trapping and mineralization. CO2 can dissolve in fresh/saline water under typical reservoir pressure and temperatures. Its solubility is dependent on pressure, temperature, and salinity. CO2 solubility studies typically consider saline water or fresh water as a liquid without any predissolved gases. The reality is formation water may contain appreciable dissolved gases for all pressure and temperature conditions. An example of gas-water ratio (GWR) can be ~1 scf/stb for formation water in an oil reservoir and ~5 to 6 scf/stb for a deep saline aquifer. Therefore, it is essential to quantify the effect of brine salinity on CO2 solubility in “live” saline waters. Just as “live” oil denotes reservoir oil that contains solution gas, we define “live” brine as saline water that includes dissolved gases. Conversely, “dead” brine refers to saline water devoid of any dissolved gas content. Two sets of experiments were conducted under typical reservoir conditions. The first set of experiments evaluated the CO2 solubility in live formation water. The second set of experiments evaluated how variation in the live brine salinity affected CO2 solubility. These experiments involved 1) synthesis of the brine, 2) synthesis of natural gas mixture, 3) recombination of live formation water with a natural gas mixture and transfer into a high-pressure and high-temperature pressure-volume-temperature (PVT) visual cell, 4) CO2 addition to the PVT cell, and 5) bubblepoint pressure determination within the PVT cell. The results showed that CO2 solubility in live formation water is significantly less than that in “dead” water under reservoir conditions. In addition, the brine salinity affects CO2 solubility in live formation water by further reducing CO2 solubility with increasing live brine salinity. As the brine salinity increases, very little CO2 can be dissolved in the live brine once it reaches a certain solubility. An understanding of CO2 dissolution in live saline water is essential for future CCUS evaluation and execution.

The impact of CO2 saturated brine salinity on wormhole generation and rock geomechanical and petrophysical properties

Deep saline aquifers are good candidates for CO2 sequestration because of their huge reserves, wide distribution, cost-effectiveness, and relatively high security. The impact of CO2 sequestration on the rock's mechanical and petrophysical properties is a complex issue that depends on a number of factors, such as salinity. This study provides insights into the potential changes in rock petrophysical and geomechanical properties due to the reactivity of CO2-saturated brine with limestone. Specifically, this article provides insights into the impact of salinity on wormhole generation and the corresponding changes in rock properties. Three Indiana limestone samples with a 1.5-inch diameter and 3-inch length, 15% average porosity, and 2 mD average permeability were used. The samples were flooded at 1 mL/min, 2000 psi, and 60 °C with different brine concentrations mixed with CO2 at a 70:30 ratio. To examine the impact of salinity, CO2 was mixed with brine concentrations of 40,000 ppm, 120,000 ppm, and 200,000 ppm for the coreflooding experiments. The samples' Young's modulus (YM) and Poisson's ratio at different confining pressures were measured before and after coreflooding. A medical CT scan was also used to visualize the generated wormholes and quantify their volumes. Results showed that it took only 14.3 pore volumes (PVs) to create a wormhole at 40,000 ppm, while 24.8 and 25.6 PVs at 120,000 ppm and 200,000 ppm, respectively. Lower salinity live brine generated a thicker wormhole compared to the other salinities. The reduction in rock strength in terms of YMs was the highest at 200,000 ppm, followed by the 120,000 ppm and then the 40,000 ppm cases. This study demonstrates that wormhole generation can substantially increase CO2 storage capacity in low-salinity aquifers; however, an increase in CO2 relative permeability indicates that it will accumulate primarily beneath the caprock. In addition, this study reveals that fresh carbonated water or water with a low salinity can be used for acid stimulation.

Assessment of Various Standard Fish Diets on Growth and Fecundity of Platyfish (Xiphophorus maculatus) and Medaka (Oryzias latipes).

Several small freshwater fish species are utilized as models for human conditions and disease in biomedical research. Research animal diets are generally tailored to optimize growth, fecundity, and produce healthy research animals. However, a lack of reference diets presents a barrier in comparative studies between aquatic animal models and even among laboratories using the same species. Therefore, the objective of this study was to determine feeding regime and dietary effects on growth and fecundity in two commonly used freshwater fish, platyfish and medaka. From 1 through 6 months of age, platyfish and medaka were fed one of three feeding regime/diets: (1) our custom feeding regime consists of commercial flake food, beef liver paste, and live brine shrimp (CON); (2) a commercially available zebrafish diet, Gemma (GEM); and (3) a laboratory defined reference feeding regime (WAT). Weight, size, brood numbers, and survival rates for both species were measured monthly. Numbers of platyfish fry and hatch rate of medaka embryos were also determined. We observed that custom feeding regime (CON) fed platyfish and medaka grew larger, exhibited a higher survival rate, and had higher fecundity than WAT or GEM fed fish. These observations suggest that diets and regimes designed for zebrafish are not optimal to maintain platyfish or medaka. Thus, base diets, with clearly defined components and regimes, need to be developed with compositions that can be adjusted in a species-specific manner.

Rock-Wettability Impact on CO2-Carbonate Rock Interaction and the Attendant Effects on CO2Storage in Carbonate Reservoirs

Deep saline aquifers and depleted carbonate reservoirs are generally considered promising locations for subsurface CO2 storage. However, carbonate minerals particularly calcite can react with CO2-saturated brine, resulting in dissolution of carbonate and potentially mechanical compaction. Thus, it is crucial to understand the extent of this reaction in both water-wet and oil-wet scenarios, and subsequently its consequences on CO2 storage in depleted carbonate reservoirs. In this study, medical X-ray computed tomography (CT) was used to image water-wet and oil-wet Indiana limestone core samples before and after CO2 flooding. Changes in the rock matrix and pore structure were further assessed from the porosity and permeability data computed from the CT images. In both cases, imaging shows a significant amount of dissolution resulting in an increase in pore volume after core flooding with live brine and subsequently CO2. This increase in porosity is 46.7% and 19% for the water-wet and oil-wet core, respectively. Likewise, the brine permeability for the water-wet core increased from 9.2 mD (before CO2 flooding) to 108 mD (after CO2 flooding), whereas the permeability for the oil-wet core increased modestly from 9.0 mD to 20.1 mD. These results suggests that the reactivity is less pronounced in the oil-wet rock compared to the water-wet rock. Therefore, the wettability state of a target carbonate reservoir and the subsequent potential for the wettability state to be modified should be considered when assessing the CO2 storage capacity and integrity.

Utilization of Live‐Food Enrichment with Polyunsaturated Fatty Acids (PUFA) for the Intensive Culture of Yellow Perch Larvae

AbstractChallenges associated with first feeding have impeded the intensive culture of larval Yellow Perch Perca flavescens. Live‐food enrichment with polyunsaturated fatty acids (PUFAs) can increase the growth and survival of larval fish, but this method has not been tested with Yellow Perch. This study includes two experiments that were meant to evaluate (1) the relative proportion of docosahexaenoic acid (DHA; 22:6[n‐3]) and arachidonic acid (ARA; 20:4[n‐6]) in enrichment emulsions and (2) the provision of PUFA emulsions in ethyl ester (EE) or triacylglycerol (TG) form on Yellow Perch growth and survival. Fish were provided with live rotifers Brachionus plicatilis and brine shrimp Artemia nauplii for the first 10 d of exogenous feeding within a specialized recirculating system (phase I). Fish were then transferred to flow‐through tanks and were fed Artemia nauplii for 3 d before gradually transitioning to a formulated starter diet (5–7 d; phase II). Fish size, growth, survival, swim bladder inflation rates, and lipid/fatty acid concentrations were evaluated after each phase. Overall, rotifers assimilated ARA in higher concentrations (23.3% of total fatty acids) than Artemia (0.6–0.7% of total fatty acids). Rotifers also tended to assimilate PUFAs better in EE form than in TG form (71.3% versus 66.5% Σn‐3 + n‐6 fatty acids). In the first experiment, fish from the ARA‐ and DHA‐enriched diet groups had greater swim bladder inflation rates (phase I) and growth rates (phase II) than the unenriched control group. In phase I of the second experiment, the EE enrichment group had a significantly faster growth rate than the TG enrichment group (specific growth rate: mean ± SD = 40.5 ± 0.9% and 36.6 ± 1.8%, respectively). Fatty acid composition of zooplankton was heavily influenced by enrichments, and fatty acid composition of larvae/juveniles reflected that of their live prey. The results of this study suggest that PUFA enrichment of live feeds can accelerate Yellow Perch growth and reduce the time spent in the critical period of early development.

A Crossover Study Comparing the Effect of a Processed vs. Unprocessed Diet on the Spatial Learning Ability of Zebrafish

The current study aimed to compare the short-term effects of processed versus unprocessed food on spatial learning and survival in zebrafish (Danio rerio). Given public concern regarding processed foods, the results of the current study can inform consumer decision-making. We hypothesized that an unprocessed diet would improve learning and survival. Zebrafish were randomly assigned to a diet of brine shrimp flakes (processed) or live brine shrimp (unprocessed). Spatial learning was evaluated throughout the study by recording fish decisions (correct vs. incorrect) and time taken for decision. Our results show no statistically significant difference in the proportion of correct decisions or in the time taken to make decisions when the groups are compared. Notably, fish receiving unprocessed food had significantly lower mortality than those receiving processed food (p = 0.027). We concluded that while the zebrafish make progressively better and faster decisions, diet type does not contribute to improved learning. However, consumption of unprocessed diet may have survival benefits in stressful environments. Future studies may further analyze this association, utilizing larger sample size and longer study duration to clearly assess the effects of long-term exposure to an unprocessed vs. raw unprocessed diet on learning. While it is an association that needs further evaluation, the current study indicates the potential benefits of an unprocessed diet in coping with stress. Considering that zebrafish are effective models of human cognition, this has implications for human consumption of processed vs. unprocessed foods as well.

Effects of heat shock protein 70 knockdown on the tolerance of the brine shrimp Artemia franciscana to aquaculture-related stressors: Implications for aquatic animal health and production

Temperature, pH, salinity and ammonia stress adversely affect the performance and well-being of aquatic organisms, especially those used in aquaculture, a major food production sector. Management strategy to mitigate stress caused by abiotic factors in farmed aquatic organisms is scarce but is highly warranted considering the negative impact of these factors on the welfare and economic production of the farmed animals. The induction of heat shock proteins, mainly 70 kDa Hsp (Hsp70), in farmed fish and shellfish, including the live feed brine shrimp Artemia franciscana, by exposure to a non-lethal heat shock (NLHS) of 37 °C for 30 min followed by 6 h recovery period caused a significant improvement in the tolerance of the animals towards subsequent challenge with an abiotic stress. Although the protective effect of NLHS was associated with enhanced Hsp70 accumulation in these species, the induction of other members of Hsp and their collective involvement in the stress tolerance could not be ignored. This triggered an argument as to whether only Hsp70 or its combination with other Hsps was responsible for inducing stress tolerance phenotype in these species. In this study, we employed RNAi technology in the biological model organism Artemia to gain insight into the functional role of Hsp70 in stress tolerance. The results showed that upon exposure to a NLHS, the wild-type Artemia nauplii capable of producing Hsp70 exhibited significantly higher survival than the unexposed control in all the abiotic stress tolerance tests performed in this study. However, the Hsp70-deficient mutant nauplii did not exhibit increased stress-tolerant phenotypes as the survival percentage of the nauplii decreased by 29, 19, and 15%, respectively, upon challenge with a median lethal concentration of salinity, pH, and ammonia. These results suggest that Hsp70 was involved in inducing tolerance against stress caused by the abiotic factors, and hence can be a potential target for developing strategies to protect economically important aquaculture species from environmental disturbances.

Stocking density effect on survival and growth of early life stages of maraena whitefish, Coregonus maraena (Actinopterygii: Salmoniformes: Salmonidae)

The maraena whitefish, Coregonus maraena (Bloch, 1779), is often considered a suitable candidate for intensive aquaculture diversification in the EU. However, only a few such farms in Europe are in operation. Rearing this species in recirculating aquaculture systems is a recent innovation, and optimisation is necessary to standardise aspects of larviculture. This 30-day study investigated the effect of stocking densities of 25/L, 50/L, 100/L, and 200/L on the survival and growth of maraena whitefish larvae in a recirculating aquaculture system. The four groups of larvae (initial weight = 7.4 ± 0.1 mg; initial total length = 13.0 ± 0.1 mm) in three repetitions were reared in a recirculating system. Larvae were fed fresh live brine shrimp metanauplii every 3 h at a rate converted to larval stocking density. After the experiment, 10 larvae from each tank (30 of each density group) were weighed on a digital microbalance (ABJ 220-4M KERN, Germany, readout = 0.1 mg) and measured manually on images taken with Leica MZ16 A stereomicroscope and a digital colour camera with 5-megapixel resolution for Leica DFC420 Image Analysis. No significant differences in final body weight, total length, size heterogeneity, condition factor, or survival were found among treatments (P > 0.05). The highest non-significant survival rate and growth parameters were observed in larvae reared at 25/L. On the contrary, it is possible to rear maraena whitefish larvae at high stocking density without any subsequent negative consequences for growth and survival. As no significant differences in any evaluated parameter were observed between groups of larvae at the highest and lowest stocking density, we conclude that it is possible to rear maraena whitefish larvae at high stocking density (and 200/L) without any subsequent negative consequences for growth and survival.

Carbonate rock mechanical response to CO2 flooding evaluated by a combined X-ray computed tomography – DEM method

Carbonate rock is a potential host for carbon dioxide storage. It is likely to react with carbonated water, following CO2 dissolution and dissociation in formation fluids. This might lead to carbonate dissolution or precipitation, depending on pH and formation fluid composition. In case of dissolution, the formation gets mechanically weaker, which could pose a risk for the mechanical stability of the formation, requiring a deeper understanding. In this paper, we used a direct CT scanning – DEM (Discrete Element Method) combined method to investigate how limestone rock mechanical properties change during CO2 injection. The results show that the minor dissolution happened after scCO2 injection, but such damage was much weaker when compared with the sample after live brine flooding. Related morphology change directly affects the rock mechanical response where the maximum compressive stress dropped from 17.2 MPa (for dead brine saturated), to 14.8 MPa (for scCO2 injection), and to 7.9 MPa (under live brine injection). We thus conclude that CO2 injection into pure carbonate reservoirs can impact the mechanical strength of matrix rock, and that the applied DEM models work well since they predicted a reliable stress-strain curve.

Microbiome and Functional Analysis of a Traditional Food Process: Isolation of a Novel Species (Vibrio hibernica) With Industrial Potential.

Traditional food preservation processes are vital for the food industry. They not only preserve a high-quality protein and nutrient source but can also provide important value-added organoleptic properties. The Wiltshire process is a traditional food curing method applied to meat, and special recognition is given to the maintenance of a live rich microflora within the curing brine. We have previously analyzed a curing brine from this traditional meat process and characterized a unique microbial core signature. The characteristic microbial community is actively maintained and includes the genera, Marinilactibacillus, Carnobacterium, Leuconostoc, and Vibrio. The bacteria present are vital for Wiltshire curing compliance. However, the exact function of this microflora is largely unknown. A microbiome profiling of three curing brines was conducted and investigated for functional traits by the robust bioinformatic tool, Tax4Fun. The key objective was to uncover putative metabolic functions associated with the live brine and to identify changes over time. The functional bioinformatic analysis revealed metabolic enrichments over time, with many of the pathways identified as being involved in organoleptic development. The core bacteria present in the brine are Lactic Acid Bacteria (LAB), with the exception of the Vibrio genus. LAB are known for their positive contribution to food processing, however, little work has been conducted on the use of Vibrio species for beneficial processes. The Vibrio genome was sequenced by Illumina MiSeq technologies and annotated in RAST. A phylogenetic reconstruction was completed using both the 16S rRNA gene and housekeeping genes, gapA, ftsZ, mreB, topA, gyrB, pyrH, recA, and rpoA. The isolated Vibrio species was defined as a unique novel species, named Vibrio hibernica strain B1.19. Metabolic profiling revealed that the bacterium has a unique substrate scope in comparison to other closely related Vibrio species tested. The possible function and industrial potential of the strain was investigated using carbohydrate metabolizing profiling under food processing relevant conditions. Vibrio hibernica is capable of metabolizing a unique carbohydrate profile at low temperatures. This characteristic provides new application options for use in the industrial food sector, as well as highlighting the key role of this bacterium in the Wiltshire curing process.

Impact of Asphaltenes on Contact-Angle Variations and Surface Topography and Composition

Summary The asphaltene precipitation affects the rock/fluid interaction in a live-oil reservoir, which has a significant effect on oil recovery and flow in the production network. In this work, we examine the changes in interfacial properties (such as contact angle between the live-oil, brine, and quartz system) as well as surface topography and compositions caused by asphaltene precipitations that are related to pressure-depletion processes. The experimental method is based on the pendant-drop-shape method using a high-resolution camera for quantitative image analysis and a high-resolution digital-pressure transducer in a high-pressure high-temperature fluid cell. The contact angle with quartz was measured in the presence of deionized water as the surrounding medium at isothermal condition. The experiments were conducted in a pressure-depletion fashion, where pressure is decreased in steps capturing the asphaltene onset pressure (AOP). At each pressure stage, sufficient time was given to stabilize the contact angle. The transient experimental contact-angle data for a system containing a live oil, brine, and quartz is presented. In particular, we Show that the time of stabilization and contact angle decreases at sequential pressure steps, except near the vicinity of AOP where they have a sharp jump signifying the effect of asphaltene precipitation Use the solubility-parameter approach for asphaltene modeling to predict asphaltene precipitation from live oil at pressures between the saturation point and AOP Relate the amount of precipitation with change in interfacial properties, such as interfacial tension (IFT) and contact angle Use image-analysis techniques such as scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) to analyze the topography and composition of the quartz surface after asphaltene deposition to supplement our observation Despite that asphaltene effects on wettability alteration have been proposed, this is the first experimental evidence that pressure-depletion-driven asphaltene precipitation alters the contact angle at realistic reservoir conditions (high-pressure high-temperature live oils). These data can be used as a basis to establish the benchmark data, model calibration for managing and preventing remediation asphaltene problems, and to design the proper facility and operating conditions for efficient recovery and operational processes.

Wettability measurements on two sandstones: an experimental investigation before and after CO2 flooding

Wettability of rock–fluid systems is an important for controlling the carbon dioxide (CO2) movement and the capacities of CO2 geological trapping mechanisms. Although contact angle measurement is considered a potentially scalable parameter for evaluation of the wettability characteristics, there are still large uncertainties associated with the contact angle measurement for CO2–brine–rock systems. Thus, this study experimentally examined the wettability, before and after flooding, of two different samples of sandstone: Berea and Bandera grey sandstones. For both samples, several sets of flooding of brine (5 wt % NaCl + 1 wt % KCl in deionised water), CO2-saturated (live) brine and supercritical CO2 were performed. The contact angle measurements were conducted for the CO2–sandstone system at two different reservoir pressures (10 and 15 MPa) and at a reservoir temperature of 323 K. The results showed that both the advancing and receding contact angles of the sandstone samples after flooding were higher than that measured before flooding (i.e. after CO2 injection the sandstones became more CO2-wet). Moreover, the Bandera grey samples had higher contact angles than Berea sandstone. Thus, we conclude that CO2 flooding altered the sandstone wettability to be more CO2-wet, and Berea sandstone had a higher CO2 storage capacity than Bandera grey sandstone.

CO2‐Saturated Brine Injection Into Unconsolidated Sandstone: Implications for Carbon Geosequestration

AbstractCarbon dioxide (CO2) injection into deep depleted hydrocarbon reservoirs or saline aquifers is currently considered the best approach to large‐scale CO2 storage. Importantly, the pore structure and permeability of the storage rock are affected by fines release, migration, and reattachment in the initial stage of CO2 injection, especially in unconsolidated sandstone reservoirs. It is thus necessary to better understand the pore structure changes and the associated permeability evolution during and after CO2 injection. We thus imaged an unconsolidated sandstone at reservoir conditions before and after CO2‐saturated brine (“live brine”) injection in situ via X‐ray microcomputed tomography to explore the effects of fines migration and mineral dissolution induced by CO2 injection. We found that in the examined sample, large pores dominated the total porosity, and porosity slightly increased after live‐brine flooding. Moreover, and importantly, the pore structure changed significantly: large pores were further enlarged while small pores shrank or even disappeared. These structural changes in the tested sample were caused by mobilized fines due to the high‐fluid interstitial velocity, which eventually reattached to the grains further downstream. Furthermore, the impact of the pore structural changes on permeability were analyzed in detail numerically. These permeability results are consistent with a fines migration mechanism where reattached fines block pore throats and thus decrease permeability drastically. We therefore can conclude that live brine injected into the examined unconsolidated sandstone will slightly improve storage space (porosity slightly increased); however, injectivity may be severely impaired by the permeability reduction.

Tilapia (Oreochromis niloticus) as a Putative Reservoir Host for Survival and Transmission of Vibrio cholerae O1 Biotype El Tor in the Aquatic Environment.

Studies have reported the occurrence of Vibrio cholerae in fish but little is known about the interaction between fish and toxigenic V. cholerae as opposed to phytoplankton, which are well-established aquatic reservoirs for V. cholerae. The present study determined the role of tilapia (Oreochromis niloticus) as a reservoir host for survival and transmission of V. cholerae in aquatic environments. Three experiments were performed with one repetition each, where O. niloticus (∼2 g) kept in beakers were inoculated with four V. cholerae strains (5 × 107 cfu/mL). Firstly, infected tilapia were kept in stagnant water and fed live brine shrimp (Artemia salina) larvae daily. Secondly, infected tilapia were kept without feeding and water was changed every 24 h. Thirdly, infected tilapia were fed and water was renewed daily. Infected tilapia and non-infected controls were sacrificed on days 1, 2, 3, 7, and 14 post-inoculation and V. cholerae were enumerated in intestinal content and water. Another experiment assessed the transmission of V. cholerae from infected to non-infected tilapia. The study revealed that El Tor biotype V. cholerae O1 and V. cholerae non-O1 colonized tilapia intestines and persisted at stable concentrations during the second week of the experiment whereas the Classical biotype was undetectable after 1 week. In stagnant water with feeding, V. cholerae counts dropped to 105 cfu/ml in water and from 107 to 104 cfu/intestine in fish after 14 days. When water was renewed, counts in water decreased from 107 to 103 cfu/ml and intestinal counts went from 106 to 102 cfu/intestine regardless of feeding. All strains were transmitted from infected to naïve fish after 24 h of cohabitation. Tilapia like other fish may play an essential role in the survival and dissemination of V. cholerae O1 in aquatic environments, e.g., the seventh pandemic strains mostly. In this study, tilapia were exposed to high concentrations of V. cholerae to ensure initial uptake and follow-up studies with lower doses resembling natural concentrations of V. cholerae in the aquatic environment are needed to confirm our findings.

CO2-brine injectivity tests in high co2 content carbonate field, sarawak basin, offshore east Malaysia

We conducted relatively long duration core-flooding tests on three representative core samples under reservoir conditions to quantify the potential impact of flow rates on fines production/permeability change. Supercritical CO2 was injected cyclically with incremental increases in flow rate (2─14 ml/min) with live brine until a total of 7 cycles were completed. To avoid unwanted fluid-rock reaction when live brine was injected into the sample, and to mimic the in-situ geochemical conditions of the reservoir, a packed column was installed on the inflow accumulator line to pre-equilibrate the fluid before entering the core sample. The change in the gas porosity and permeability of the tested plug samples due to different mechanisms (dissolution and/or precipitation) that may occur during scCO2/live brine injection was investigated. Nuclear magnetic resonance (NMR) T2 determination, X-ray CT scans and chemical analyses of the produced brine were also conducted. Results of pre- and post-test analyses (poroperm, NMR, X-ray CT) showed no clear evidence of formation damage even after long testing cycles and only minor or no dissolution (after large injected pore volumes (PVs) ~ 200). The critical flow rates (if there is one) were higher than the maximum rates applied. Chemical analyses of the core effluent showed that the rock samples for which a pre-column was installed do not experience carbonate dissolution.

CO2 saturated brine injected into fractured shale: An X-ray micro-tomography in-situ analysis at reservoir conditions

Fracture morphology and permeability are key factors in enhanced gas recovery (EOR) and Carbon Geo-storage (CCS) in shale gas reservoirs as they determine production and injection rates. However, the exact effect of CO2-saturated (live) brine on shale fracture morphology, and how the permeability changes during live brine injection and exposure is only poorly understood. We thus imaged fractured shale samples before and after live brine injection in-situ at high resolution in 3D via X-ray micro-computed tomography. Clearly, the fractures’ aperture and connectivity increased after live brine injection.

Effect of temperature on growth and survival of maraena whitefish Coregonus maraena (Bloch 1779) larvae in controlled conditions

This 28-day study investigated the effect of three rearing temperatures, 11, 15 and 19°C, on survival and growth of maraena whitefish fry in a recirculating aquaculture system. Three groups of larvae in three repetitions were reared in recirculating system. Each group comprised 200 larvae. Feeding level was fixed at 500–700 Artemia sp. metanauplii per fish per day. Larvae were fed fresh live brine shrimp at 10 ml/tank every 3 hr. Significantly higher body weight (p = 0.00), total length (p = 0.00), larval yield (p = 0.00) and condition factor (p = 0.00) were obtained at 19°C compared to 15 and 11°C, as well as at 15°C compared to 11°C. Significantly higher survival (p = 0.00) was observed in larvae reared at 11 and 15°C compare to 19°C and no significant differences were observed between 11°C compared to 15°C. No significant differences in size heterogeneity among treatments were found (p = 0.46). In larviculture, the optimal assessed temperature for growth of maraena whitefish was 19°C, with highest survival observed at 11°C, at the end of this 28 days trial. The findings in this study apply to the particular study location and may not be applicable more broadly.

Permeability Evolution in Sandstone Due to CO2 Injection

Permeability variation is one of the key factors influencing the injectivity of CO2 in CO2 sequestration projects. Despite the research carried out on the subject, the results are highly inconsistent. In this study, the injection of brine (5 wt % NaCl + 1 wt % KCl), CO2-saturated (live) brine, and supercritical CO2 was performed on three homogeneous Berea sandstone plugs with a low clay content and two Bandera Gray sandstone plugs with a high clay content at reservoir conditions (10 MPa and 323 K). Porosity and permeability of the samples were measured using nuclear magnetic resonance (T2 relaxation time), and a dynamic (during flooding) permeability measurement technique, respectively, at different injection rates and injection durations. The mercury intrusion test was also performed on each sample to further evaluate its pore throat size distributions. From the results of this study, it was revealed that the CO2 injection rate is unlikely to affect the permeability significantly. It was also shown that ...