Aquaculture Water Research Articles

Transforming aquaculture monitoring with real-time solutions at Salman Assalam Science Islamic Boarding School, Cirebon

The aim of this activity is to disseminate real-time, 24-hour aquaculture water monitoring devices remotely at the Salman Assalam Science Islamic Boarding School in Cirebon, West Java. The Salman Assalam Science Islamic Boarding School manages various types of tilapia, catfish, and pomfret cultivation ponds used to support the economy and fulfill the food needs of the students. The activities include planning, implementation, and evaluation. The results of this activity include the development of a laboratory-level device, comprising a buoy, solar panels, and electronic modules with several types of electronic sensors. The device is equipped with a dashboard to observe real-time measurements in fish ponds, including parameters such as water temperature, dissolved oxygen, turbidity, pH, air temperature, humidity, battery voltage, total dissolved density, and solar cell voltage. Data is presented in the form of graphs and tables accessible via a web browser, allowing partners to access it from laptops or smartphones.

Post-synthetic functionalization of UiO-66-NH2 by polyacrylamide and polyvinylimidazolium salt brushes via ATRP and adsorption behavior

Aquacultural water pollution caused by methylene blue is an urgent environmental problem, posing a serious threat to aquaculture and human health. Adsorption is a potential and promising method to remove methylene blue from aquaculture water. In this study, UiO-66-NH2@PAM and UiO-66-NH2@PVIO post-synthetic functionalized by polyacrylamide and polyvinylimidazolium salt brushes onto UiO-66-NH2 by virtue of ATRP method were successfully synthesized, and adsorption performance for methylene blue were systematically studied. Adsorption kinetic curves with trend of first increase, and decrease, and then increase was explained by capillary effect. Experimental data were fitted best by pseudo second-order kinetic and Langmuir isotherm model. UiO-66-NH2@PVIO had comparatively higher adsorption capacities than UiO-66-NH2@PAM, because UiO-66-NH2@PVIO had stronger adsorption affinity and binding energy for methylene blue than UiO-66-NH2@PAM. Adsorption driving forces were electrostatic interaction, π-π conjugation effects, hydrogen-bonding interactions, induced dipoles, van der Waals forces, sieving effect so that adsorption processes were ascribed to physical adsorption. UiO-66-NH2@PAM and UiO-66-NH2@PVIO had very good reusability and stability, and could be utilized in practical application. The results can offer better help for the synthesis of MOF materials by the technology of post-synthetic functionalization, and provide technical guidance for actual application in dye removal from aquacultural water.

Optimizing aeration efficiency and forecasting dissolved oxygen in brackish water aquaculture: Insights from paddle wheel aerator

BackgroundAquaculture relies significantly on effective aeration systems to ensure optimal conditions for aquatic organisms. This 96-day study investigates the dynamic relationship between Oxygen Transfer Rates (OTR) and seasonal variations, with a specific focus on the impact of seasonal dynamics and the placement of paddle wheel aerators. The study recognizes the pivotal role of Total Dissolved Solids (TDS) and Total Suspended Solids (TSS) as key water quality parameters influencing aeration efficiency. MethodologyA series of water circulation experiments were conducted at regular intervals to assess mixing rates, revealing a nuanced trajectory ranging from 27.05 to 14.22 m³/kWh. The study scrutinized the influence of TDS and TSS on these rates. Additionally, water velocity variations, ranging from 0.45 to 1.67 m/s, were examined, highlighting density-dependent changes, particularly evident post four weeks of operation. Oxygen stratification analysis provided insights into deviations in Dissolved Oxygen (DO) concentrations, with particular attention to climatic aberrations. Rigorous statistical analyses, including chi-squared, Pearson correlation, Gaussian distribution checks, and student's t-tests, validated the methodological robustness and data reliability. Significant findingsEmploying a Seasonal Auto Regressive Integrated Moving Average (SARIMA) model, the study achieved a remarkable 97 % accuracy in forecasting DO levels for the subsequent 96 days. Real-time validation, complemented by a Chi-square goodness of fit test, reaffirmed the model's reliability, establishing congruence between observed and forecasted values. This research underscores the critical roles of strategic aerator placement and seasonal considerations in optimizing pond aeration efficiency, providing substantive insights for the sustainable management of aquaculture ecosystems.

Microalgae Inoculation Significantly Shapes the Structure, Alters the Assembly Process, and Enhances the Stability of Bacterial Communities in Shrimp-Rearing Water.

Intensive shrimp farming may lead to adverse environmental consequences due to discharged water effluent. Inoculation of microalgae can moderate the adverse effect of shrimp-farming water. However, how bacterial communities with different lifestyles (free-living (FL) and particle-attached (PA)) respond to microalgal inoculation is unclear. In the present study, we investigated the effects of two microalgae (Nannochloropsis oculata and Thalassiosira weissflogii) alone or in combination in regulating microbial communities in shrimp-farmed water and their potential applications. PERMANOVA revealed significant differences among treatments in terms of time and lifestyle. Community diversity analysis showed that PA bacteria responded more sensitively to different microalgal treatments than FL bacteria. Redundancy analysis (RDA) indicated that the bacterial community was majorly influenced by environmental factors, compared to microalgal direct influence. Moreover, the neutral model analysis and the average variation degree (AVD) index indicated that the addition of microalgae affected the bacterial community structure and stability during the stochastic process, and the PA bacterial community was the most stable with the addition of T. weissflogii. Therefore, the present study revealed the effects of microalgae and nutrient salts on bacterial communities in shrimp aquaculture water by adding microalgae to control the process of community change. This study is important for understanding the microbial community assembly and interpreting complex interactions among zoo-, phyto-, and bacterioplankton in shrimp aquaculture ecosystems. Additionally, these findings may contribute to the sustainable development of shrimp aquaculture and ecosystem conservation.

Cross-contamination and ecological risk assessment of antibiotics between rivers and surrounding open aquaculture ponds

Antibiotics are causing widespread concern as one of the emerging contaminants. There is the abuse of antibiotics in high-density open aquaculture, and the tailwater is often discharged into surrounding rivers. At the same time, the water replenishment of open aquaculture ponds from nearby rivers containing antibiotic contamination from different sources may result in cross-contamination. However, it is still unclear which pollution intensity is greater in rivers or in open aquaculture. So in this paper, the levels of 20 antibiotics (i.e., Fluoroquinolones (FQs), Sulfonamides (SAs), Tetracyclines (TCs), Macrolides (MLs) and Lincosamides (LCs)) in rivers and high-density open aquaculture ponds were investigated in the Baini River basin in the suburbs of Guangzhou, China. The results showed that norfloxacin (NFX) was the predominant antibiotic in river and aquaculture water, with concentrations ranging from 6.12 to 156.04 ng/L and from 7.47 to 82.62 ng/L in both aquatic systems, respectively. As for the pollution intensity of antibiotics, the annual pollution contribution (28.64 kg/a) of the river water supply to open aquaculture is higher than that (10.81 kg/a) of open aquaculture to the river, which means river pollution has a greater impact on aquaculture ponds. The risk quotient (RQ) showed that the ecological risk of lincomycin (LIN), erythromycin (ERY), sulfamethoxazole (SMX), norfloxacin (NFX), ciprofloxacin (CFX) and chlortetracycline (CTC) in rivers and aquaculture environments had high ecological risks from 1.21 to 1.81. Water interactions with contaminated rivers will result in a corresponding increase in the ecological risk of antibiotics in the aquaculture environment. Overall, according to the results, the risk of polluted rivers to open aquaculture cannot be ignored, and it is recommended that open aquaculture should use these water sources with caution, and that the water quality evaluation of aquaculture water should be increased with monitoring indicators for emerging contaminants such as antibiotics.

Artificial Intelligence Techniques based on aquaculture solar thermal water heating system control

The One of the most promising applications of hot water is aquaculture. Temperature is one of the most principle parameters affects aquaculture life. It can cause stress and mortality or superior environment for growth and reproduction. Shrimp is warm water aquaculture type need hot water supply. To increase pond production it is necessary to keep water temperature at 34oC. Artificial intelligence (AI) techniques are becoming useful as alternate approaches to conventional techniques or as components of integrated systems. They have been used to solve complicated practical problems in various areas and are becoming more and more popular nowadays. In this paper a control system using artificial neural network control (NNC) either adaptive fuzzy logic control (AFLC) are design to control the hot water temperature. A comparison study is applied between the performance of FLC and NNC. The performance of NNC is the best because the control design takes into consideration different variables which give an accurate output than FLC. Also this paper introduces a complete mathematical modeling and MATLAB SIMULINK model for the proposed aquaculture heating system.

A fast and specific near‐infrared fluorescent probe for hydrogen sulfide detection in aquaculture freshwater

AbstractThe content of Hydrogen sulfide (H2S) is one of the most important indicators of aquaculture water quality monitoring, which has a profound impact on the survival of aquatic animals and the income of aquaculture. Therefore, it's of great significance to develop an accurate and convenient detection method for the detection of hydrogen sulfide in aquaculture. Herein, using 2,4‐dinitrophenyl (DNP) ether as the detection group, a novel near‐infrared (NIR) fluorescent probe, X‐NO2, based on the hemicyanine fluorophore, was designed and synthesized for H2S detection in aquaculture. Accompanied by a noticeable color change from purple to blue, the probe X‐NO2 shows strong fluorescence at 685 nm when H2S mediates the thiolysis of DNP ether and release X‐OH. In 10 % DMSO‐PBS (pH=7.4,10 mM,v/v), the probe X‐NO2 shows high selectivity to H2S than other anions and some somebiologicalthiols, and strong anti‐interference capacity. Probe X‐NO2 also has short response time (within 3 min) and low detection limit (65 nM) towards H2S and has a stable performance over a wide pH range (6‐9) in hydrogen sulfide monitoring system. Moreover, probe X‐NO2 was used to determine the H2S levels in real water samples from aquaculture accurately and conveniently, which shows a good application prospect in the future.

Revealing the response characteristics of periphyton biomass and community structure to sulfamethoxazole exposure in aquaculture water: The perspective of microbial network relationships

The widespread application of sulfonamide antibiotics in aquaculture has raised concerns about their adverse environmental impacts. Periphyton plays a crucial role in the aquatic ecosystem. In this study, we examined sulfamethoxazole (SMX) effects on the community structure and interactions of periphyton in simulated aquaculture water. Our findings indicated that the total biomass of periphyton decreased, while the biomass of periphytic algae and the secretion of extracellular polymeric substances (EPS) increased at 0.7 × 10−3 mg/L. Under higher SMX concentrations (5 mg/L and 10 mg/L), periphyton growth was severely inhibited, the microbial community structure of periphyton were sharply altered, characterized by the cyanobacteria growth suppression and decrease in the diversity index of community. Furthermore, elevated SMX concentrations (5 mg/L and 10 mg/L) increased the ratio of negative relationships from 45.4% to 49.4%, which suggested that high SMX concentrations promoted potential competition among microbes and disrupted the microbial food webs in periphyton. The absolute abundance of sul1 and sul2 genes in T2 and T3 groups were 2–3 orders of magnitude higher than those in control group after 30 days of SMX exposure, which elevated the risk of resistance gene enrichment and dissemination in the natural environment. The study contributes to our understanding of the detrimental effects of antibiotic pollution, which can induce changes in the structure and interaction relationship of microbial communities in aquaculture water.

Temporal patterns of physicochemical and bacteria profiles of static aquaculture systems: insights into health hazards for fish and the public

Knowledge on water quality in static aquaculture systems is crucial to gain understanding of health threats to fish or aquaculture personnel. In the present study, we investigated the temporal profiles of the bacteriological profiles and physicochemical status of static water aquaculture systems (earthen ponds and concrete tanks). All physicochemical parameters measured were within the optimum recommendation. Following microbial analyses in earthen pond water, the TVC and TCC showed temporal variations with concentration increasing with sampling time, however, FCC fluctuated, and 8 bacteria groups were isolated from both rearing enclosures. In which Gram (-) bacteria showed dominance, with 5 Gram negative (Escherichia coli, Proteus spp, Serratia spp, Enterobacter spp and Pseudomonas spp) and 3 Gram positive (Staphylococcus spp, Streptococcus spp, and Bacillus spp) encountered. From earthen pond water, the following microbial occurrences were reported: Staphylococcus spp (20%), Streptococcus spp (12%) Proteus spp (8%) Enterobacter spp (20%) Serratia spp (16%), Bacillus spp (9%), Escherichia coli (8%), Pseudomonas spp (7%). While Staphylococcus spp (18%), Streptococcus spp (16%), Proteus spp (8%), Enterobacter spp (22%), Serratia spp (8%), Bacillus spp (15%), Escherichia coli (8%), Pseudomonas spp (6%) occurred in concrete water. Taken together, although the physicochemical condition raised no well-fare concern, however, the bacteriological profile during this investigation showed potential health risk in static water aquaculture condition or to adjacent aquatic environment from end of production-discharge.

Analysis of brominide disinfection by-products (DBPs) in aquaculture water using ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-tof/MS).

halogenic disinfectants have been shown to produce toxic and carcinogenic disinfection by-products in the water disinfection process. Dibromohydantoin (DBDMH) is a commonly used water disinfectant in aquaculture. Aquaculture water has more complex matrix, and the analytical method for disinfection by-products (DBPs) have not been reported. Since the content of DBPs is related to the external conditions such as ultraviolet irradiation, temperatures, pH and humic acid. The semi-target screening method for mainly DBPs based on tracing mass spectrometry fragments of bromide and accurate mass of high resolution mass spectrometry was established by ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q-tof/MS). Br-DBPs as a important class of DBPs from DBDMH, which quantification analysis methods were developed based on accurate mass of high resolution mass spectrometry. through screening method to identify unknown Br-DBPs and quantitative analysis of the typical 4-bromophenol by-product of accurate mass was established. The conditions of the instrument parameters of mass spectrometry and SPE sample preparation procedure in complex real sample were optimized. The high efficiency method was demonstrated for the determination of Br-DBPs with a good linear correlation (R2 = 0.999) in the range of 0.500-200 μg L-1 and limit of detections (LODs) and limit of quantifications (LOQs) were 0.0250 ng L-1 and 0.0834 ng L-1, respectively. the developed screening and quantification analytical strategy for Br-DBPs is rapid, accurate and sensitivity applicable for environmental in aquaculture water monitoring.

Corals-inspired magnetic absorbents for fast and efficient removal of microplastics in various water sources.

Microplastics (MPs) as the formidable pollutants with high toxicity and difficult degradation may threaten the aquaculture industry and human health, making it highly necessary to develop the effective removal methods. In this article, Fe3O4 nanoparticles (NPs) were initially fabricated with mesoporous structure, but showing undesirable adsorption efficiencies for the adsorption of MPs (lower than 70%). Inspired by the reefs-rebuilding corals acting as the sinks for various marine pollutants like plastic, Fe3O4 NPs were coated further with adhesive polymerized dopamine (PDA) yielding Fe3O4@PDA absorbents. Unexpectedly, it was discovered that the corals-mimicking absorbents so formed could allow for the removal of MPs with dramatically enhanced efficiencies up to 98.5%, which is over about 30% higher than those of bare Fe3O4 NPs. Herein, the PDA shells might conduct the increased adhesion to MPs, presumably through the formation of hydrogen bonding, π-π stacking, and hydrophobic interactions. A fast (within 20 min) and stable adsorption of MPs can also be expected, in addition to the PDA-improved environmental storage of Fe3O4 NPs. Subsequently, the Fe3O4@PDA adsorbents were utilized to remove MPs from different water sources with high efficiencies, including pure water, suburban streams, village rivers, lake water, inner-city moats, and aquaculture water. Such a magnet-recyclable adsorbent may provide a new way for rapid, effective, and low-cost removal of MPs pollutants from various water systems.

Biologic and genomic characterization of a novel virulent Aeromonas hydrophila phage phiA051, with high homology to prophages.

Aeromonas hydrophila is particularly harmful to freshwater aquaculture, and the search for phage is an effective biological control method, but reports of possible temperate phages and their mutants are rare in this field. In this study, a virulent phage highly homologous to prophage in the genomes of A. hydrophila was collected and preliminary biological characterization was carried out to understand its nature. Water samples taken from eel ponds in Fujian, China were combined with the strain. Spot test method and double-layer agar plate assay was used for confirmation and purification. Phage virions were observed using transmission electron microscope. A total of 68 strains of Aeromonas spp. were used to determine the host range. MOI groups of 1,000, 100, 10, 1, 0.1, 0.01, 0.001, 0.0001, 0.00001 were prepared to detect the optimal MOI. The conditions of thermal stability assay were set as 30, 40, 50, 60, 70 and 80°C for 1 h, respectively, and conditions of acid and alkali stability assay were set as 2.0, 4.0, 6.0, 8.0, 10.0 and 12.0 of pH. MOI of 0.01 and 0.1, respectively, are set to determine the inhibitory capacity of phage. A novel virulent A. hydrophila phage designated phiA051 has been isolated from aquaculture water. Electron microscopic observation showed that the phage phiA051 was composed of an icosahedral capsid. The phage phiA051 possesses an optimal multiplicity of infection (MOI) of 0.01, and its burst size was 108 PFU/cell. The phage maintained a high viability at temperatures of 30-50°C or pH 6.0-10.0 for 1 h. Phage phiA051 has certain potentials in rapidly inhibiting the spread of pathogen early in the outbreak, and it has a linear dsDNA with GC content of 60.55% and a total length of 32,212 bp, including 46 ORFs. The phage phiA051 behaved as a virulent phage. However, the BLASTN result showed that 23 of the top 25 hits were genomes of Aeromonas strains. It was suggested that phiA051 was probably derived from some prophage in the chromosome of Aeromonas. Further investigation of the mechanism how phage phiA051 transforms from a temperate phage to a virulent phage will provide a unique perspective and idea to explore the potential of prophages.

Connecting Aquaculture to the Internet of Things A Model for Aquaculture Quality and Water Preservation

Connecting Aquaculture to the Internet of Things A Model for Aquaculture Quality and Water Preservation

Effects of Different Salinity Levels on Performance of Nile Tilapia Fingerlings in a Biofloc Culture System

Abstract Especially in arid regions, developing tilapia culture with the ability to survive a wide range of salinities is crucial due to the limited availability of fresh water for aquaculture. The present study focused on evaluating the growth performance of Nile tilapia in a biofloc system under three salinity levels: 0 (BFT0), 4 (BFT4), and 8 g/L (BFT8). Fingerling fish were raised for 37 days in tanks with a water volume of 140 liters and a stocking density of one fish per liter. The results of the water quality parameters showed that dissolved oxygen and pH decreased with increasing salinity. Furthermore, the BFT8 group had the highest concentrations of settled solid (19.98 ml/L) and total suspended solid (428.37 mg/L), while the BFT8 group had the lowest TAN concentration (4.32 mg/L). The final weight and specific growth rate were significantly higher in the BFT8 and BFT4 groups compared to the BFT0 group. Survival rates were not significantly different across treatments, and all of them were higher than 97%. The protein and lipid content of Nile tilapia bodies and bioflocs decreased with increasing salinity, while the ash content increased. The highest body ash content in Nile tilapia (13.81% of dry weight) and bioflocs (31.78% dry weight) was found at 8 g/L salinity. Based on the present study, it is suggested that salinities of 4 and 8 g/L can improve water quality, growth performance, survival, and carcass composition of Nile tilapia fingerlings in the biofloc system. This finding suggests that brackish waters can be utilized for sustainable aquaculture for the rearing of Nile tilapia.

A paper-based ratiometric fluorescence sensor based on carbon dots modified with Eu3+ for the selective detection of tetracycline in seafood aquaculture water.

Paper-based ratiometric fluorescence sensors are normally prepared using two or more types of fluorescent materials on a paper chip for simple, low-cost and fast detection. However, the choice of multi-step and one-step modifications on the paper chip affects the analytical performance. Herein, a novel paper-based dual-emission ratiometric fluorescence sensor was designed for the selective detection of tetracycline (TC). Carbon dots (CDs) modified with Eu3+ were combined with a sealed paper-based microfluidic chip by two methods: one-step grafting of CDs-Eu3+ on paper and step-by-step grafting of CDs and Eu3+ on paper. The analytical performance was studied and optimized respectively. The red fluorescence of Eu3+ at 450 nm is enhanced and the blue fluorescence of CDs at 617 nm is quenched by energy transfer in the presence of TC. Under optimal conditions, TC is selectively determined in the linear range from 0.1 μM to 100 μM with a detection limit of 0.03 μM by the step-by-step grafting method. In addition, the sealed paper chip could effectively prevent pollution and volatilization from the reagent. This technique has been used to analyze TC in seafood aquaculture water with satisfactory results.

Structural transition route of aquacultural water surfaces on the Jianghan Plain and mechanisms

Structural transition route of aquacultural water surfaces on the Jianghan Plain and mechanisms

Effects of Astaxanthin on Growth Performance, Gut Structure, and Intestinal Microorganisms of Penaeus vannamei under Microcystin-LR Stress.

Microcystin-LR (MC-LR) are biologically active cycloheptapeptide compounds that are released by cyanobacteria during water blooms and are extensively found in aquatic ecosystems. The Penaeus vannamei is a significant species in global aquaculture. However, the high level of eutrophication in aquaculture water frequently leads to outbreaks of cyanobacterial blooms, posing a significant threat to its sustainable cultivation. Astaxanthin (AX) is commonly utilized in aquaculture for its physiological benefits, including promoting growth and enhancing immune function in cultured organisms. This study aimed to examine the protective effect of astaxanthin on P. vannamei exposed to microcystin-induced stress. The experiment consisted of three groups: one group was fed formulated feed containing MC (100 μg/kg), another group was fed formulated feed containing MC (100 μg/kg) + AX (100 mg/kg), and the third group was fed basic feed (control group). After 15 days of feeding, the specific growth rate (SGR) was significantly higher in the MCAX group (2.21% day-1) compared to the MC group (0.77% day-1), and there was no significant difference between the MCAX group (2.21% day-1) and the control group (2.24% day-1). Similarly, the percent of weight gain (PWG) was also significantly higher in the MCAX group (14.61%) compared to the MC group (13.44%) and the control group (16.64%). Compared to the control group, the epithelial cells in the MC group suffered severe damage and detachment from the basement membrane. However, in the MCAX group, although there was still a gap between the intestinal epithelial cells and the basement membrane, the overall intestinal morphology was slightly less impaired than it was in the MC group. The analysis of the intestinal microbiota revealed a significant disparity in the community composition (chao 1 and ACE) between the MC and MCAX groups. When comparing the various bacterial genera, the MC group exhibited an increase in Vibrio abundance, whereas the MCAX group showed a decrease in both Shewanella and Vibrio abundance. The results indicate that AX has a positive impact on the growth performance and resistance of P. vannamei against MC by regulating the composition of the intestinal microbiota. AX can be utilized to mitigate the detrimental effects of MC in aquaculture practices. This function could be attributed to the role of AX in preserving the structural integrity of the intestinal mucosa and regulating the composition of the intestinal microbiota.

Increasing carbon and nutrient burial rates in mangroves coincided with coastal aquaculture development and water eutrophication in NE Hainan, China

Mangroves sequester and store large area-specific quantities of blue carbon (C) and essential nutrients such as nitrogen (N) and phosphorous (P). Quantifying C and nutrient burial rates in mangroves across a centennial time span and relating these rates to mangrove habitat is fundamental for elucidating the role of mangroves in carbon and nutrient budgets and their responses to environmental changes. However, relevant data are very limited in China. In this study, we used the radionuclides (210Pb and 137Cs) to determine chronologies and C, N and P burial rates in two mangrove forests located at different geomorphologic settings in NE Hainan Island, China. We found that the temporal patterns of C, N and P burial rates since 1900 fitted a quadratic function with a notable increase after 1960s in both mangroves, which coincided with the rapid development of coastal aquaculture since 1960s in NE Hainan and the subsequent coastal water eutrophication in this area. Sediment accretion rate (SAR) and mass accumulation rate (MAR) stayed relatively steady in the open-coastal mangroves, while they increased exponentially in the estuarine mangroves since 1900. The estuarine mangroves had significantly higher SAR and C, N and P burial rates than the open-coastal mangroves. C, N and P burial rates averaged at 141.52 g m−2 a−1, 6.27 g m−2 a−1 and 1.14 g m−2 a−1, respectively in the estuarine core, and these rates averaged at 61.71 g m−2 a−1, 3.71 g m−2 a−1 and 0.43 g m−2 a−1, respectively in the open-coastal core. The results suggest that estuarine mangroves may be more capable of surviving accelerating sea level rise under climate change and play a greater role in C accumulation and nutrient filtering under anthropogenic nutrient enrichment than marine-dominated mangroves. Blue C burial may be enhanced by coastal water eutrophication, but such a relationship needs to be tested in further studies.

Occurrence, distribution, sources, and risk assessment of organophosphate esters in typical coastal aquaculture waters of China

This study monitored 20 organophosphate esters (OPEs) in water and sediment from three typical mariculture bases (Yunxi Marine Ranching (YX), Hangzhou Bay (HZB), and Zhelin Bay (ZLB)) and Meiliang Bay (MLB) of Taihu Lake in China, focusing on the spatial distribution and sources of OPEs. Moreover, the occurrence and risk of OPEs in fishes from ZLB were evaluated. The ∑OPE concentrations in waters followed the order MLB (591 ng/L) > YX (102 ng/L) > HZB (70.0 ng/L) > ZLB (37.4 ng/L), with tri(1-chloro-2-propyl) phosphate (TCIPP), triethyl phosphate (TEP), and tri(2-chloroethyl) phosphate (TCEP) being the dominant OPEs. Significantly higher ∑OPE concentrations were found in sediment in MLB compared to the other three areas with similar levels. The decreasing concentrations of OPEs from nearshore to offshore areas in HZB and MLB indicated that terrigenous input is the main source of OPEs. The even distribution of OPEs in YX and ZLB combined with PCA analysis suggested ship traffic or aquaculture activities are also potential sources. The ∑OPE concentrations in fishes ranged from 0.551–2.45 ng/g wet weight, with TCIPP, tri-phenyl phosphate (TPHP), and TCEP being the main OPEs. Hydrophobicity was a key factor affecting the sediment-water distribution coefficients and the bioaccumulation factors of OPEs. The human exposure to OPEs through consumption of fishes from ZLB had a low health risk.

Amyloodiniosis in aquaculture: A review

AbstractFish ectoparasites are one of the pathogens groups that pose great concern to the aquaculture industry. The dinoflagellate Amyloodinium ocellatum is responsible for amyloodiniosis, a parasitological disease with a strong economic impact in temperate and warm water aquaculture, mainly in earthen pond semi‐intensive systems. Amyloodiniosis represents one of the most important bottlenecks for aquaculture and, with the predictable expansion of the area of influence of this parasite to higher latitudes due to global warming it might also be a threat to other aquaculture species that are not yet parasitized by A. ocellatum. This review made a compilation of the existing knowledge about this parasite and the disease associated with it. It was noticed that, except from the life cycle characterisation, detection methods, histopathological analysis, and treatments, there are still a lot of areas that need a further investment in research. Areas like parasite–host interactions, epidemiological models, taxonomy, host physiological responses to parasitism, and genome sequencing, amongst others, can contribute to a better understanding of this disease. These proposed approaches and routes of investigation will enhance and contribute to a more standardised knowledge, creating the opportunity for a better understanding of amyloodiniosis impacts on fish and contributing for the development of new tools against A. ocellatum, that may reduce fish mortality in aquaculture production due to amyloodiniosis outbreaks.