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This study summarises the scenario of maritime traffic anomalies, like the increased congestion and U-turn of ships caused by the ship grounding in the Suez Canal in March 2021. Here, satellite automatic identification system based ship trajectories, and Sentinel-1 and Sentinel-2 images based ship positions are analysed after subdividing the study area into seas, lakes and canals. The results show that the blockage affected the maritime traffic for more than three weeks, waiting ship numbers increased from 5 to 122, and daily one to three ships made a U-turn between 23 and 31 March in the Gulf of Suez. Ship density also increased to more than double in Bitter Lakes with a minimum waiting time of 7 days. Hence, to avoid such prolonged waiting of ships, we propose a warning method based on the sharp speed decrease rate, U-turn and congestion.

This study aimed to investigate the seasonal and spatial variations in water quality parameters and determine the main contamination sources in the Shari-Goyain River, Bangladesh. Therefore, surface water was sampled monthly from six sampling sites, where six water quality parameters were evaluated. Data were analyzed by applying the Canadian Council of Ministers of the Environment (CCME) water quality index (WQI) and multivariate statistical methods. The results reveals that most of the examined water quality parameters crossed the acceptable range, and significant variations were observed spatiotemporally (p < 0.05). Based on the CCME WQI value, the water quality of the river is classified as poor to marginal with a score range between 33.40 and 51.30. This range of values demonstrates that the river’s water quality is far from desirable for aquatic life and that it is being impacted and deteriorated by external drivers. Principal component analysis (PCA) retained two principal components (Factors 1 and 2), explaining about 79.17% of the total variance in the studied parameters and identified acidic pollution sources. Cluster analysis also reveals relative differences in water quality throughout sites and seasons, which supported the CCME WQI and PCA. Finally, Kruskal-Wallis one-way analysis of variance by ranks has identified coal mine drainage (CMD) as the main pollutant source for the Shari-Goyain River. In order to mitigate the CMD impact on land and water, different nature-based solutions are proposed, particularly passive mine water treatment approaches through constructed wetlands that could also mitigate the transboundary waters problem.

Determining a suitable stocking density of fish for an ambient condition is very important for economic benefit in cage aquaculture, which is not yet tested for many species in Sylhet district of Bangladesh. Therefore, current research was conducted in order to explore the effect of various stocking densities on growth and production performances of mono-sex Nile tilapia cage aquaculture in an open running water body, the Gurukchi River. Considering maximizing economic benefit, it is the first instance of such research in the Sylhet district of Bangladesh. In the three treatments (T1, T2, and T3), fingerlings were stocked at 40, 60 and 80 fish/m3, respectively with initial weights of 39.51 ± 0.91, 39.61 ± 0.71 and 38.54 ± 0.57g, respectively. Fish were fed with commercial floating pellet feed at 8-4% of their body weight. The results showed that growth performance of Nile tilapia significantly decreased with increasing stocking density. The mean total yields were 13.25 ± 0.48, 18.43 ± 0.88 and 22.76 ± 0.63 kg/m3 in T1, T2 and T3, respectively, which showed significant variations (p < 0.05) among treatments. The benefit-cost ratio analysis revealed that T1 (1.512 ± 0.022) and T2 (1.499 ± 0.063) were significantly (p < 0.05) higher than T3 (1.191 ± 0.071), with no significant differences observed between T1 and T2. Notably, a significantly higher (p < 0.05) net profit was observed in T2 than in T1 and T3. Overall, 60 fish/m3 stocking density was the best stocking density for commercial cage aquaculture of tilapia in a riverine environment of the north-eastern Bangladesh.

Fish sanctuary is considered as an important structural management tool for restoring fish biodiversity and enhancing fisheries production. Therefore, this study was conducted in the Ratargul Swamp Forest (RSF) of Bangladesh to evaluate the impact of a fish sanctuary on native fish biodiversity in and around the forest ecosystem. The investigation was carried out through focus group discussions, personal interviews, and direct catch assessments during fishing operations by the local fishers. After two years of study, 65 species of indigenous fishes were recorded for 46 genera under 23 families covering 9 orders, where Cypriniformes and Cypriniidae are the dominant order and family, respectively. After the establishment of the fish sanctuary, there was an increasing tendency of fish population was observed in the RSF and the adjacent Shari-Goyain and Kapna Rivers. In the RSF, fish diversity indices such as Simpson dominance index (D), Shannon-Wiener diversity index (H), Margalef richness index (d), and Pielou evenness index (J) varied from 0.12-0.09, 2.77-2.98, 6.15-6.14, and 0.66-0.71, respectively indicating species diversity enrichment in the final year compared to baseline assessment year which is supposed to be associated with the impact of fish sanctuary establishment. That assumption is further supported by remarkable increase in average fish catch (11.38%). Local fishers and people adjacent to RSF perceive that sanctuary became useful for protecting biodiversity, increasing fish production as well as improving their livelihood conditions.

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This study was conducted in the Dhanu River and adjacent waters at Mithamain upazila (sub-district) under Kishoreganj district of Bangladesh to prepare a check list of available native fishes with their availability status, conservation perspectives, habitat preferences, population trends and intimidations. Data were collected monthly by direct field survey, focus group discussions, and personal interviews with fishers by using a semi-structured questionnaire and a pictorial check list of fish species. A total of 91 indigenous fish species of 59 genera belonging to 29 families under 11 orders were documented where 17.58% species was abundantly available, 27.47% was commonly available, 31.87% was moderately available and 23.08% was rarely available. Cypriniformes was found as the dominant order, consisting 37.36% of the fish species aggregation and Cyprinidae was the most dominant family with 32.97% of the entire species assemblage. Twenty four piscine species (26.37%) were under threatened category in Bangladesh which subsumed 3 critically endangered (3.29%), 11 endangered (12.08%), and 10 vulnerable species (10.99%). Notably globally threatened Cirrhinus cirrhosus, Channa orientalis, and Wallago attu were available there. Fish population trends of 24.18% and 59.34% of the entire fish species was found in decreasing trends in global and national level, respectively. Leading intimidation to the fish diversity was indiscriminately overfishing, followed by fishing by dewatering of wetlands, katha fishing method, use of deprecated fishing gears, climate change, etc. Minimization of anthropogenic impacts, assuring the flux of water round the year, enactments of fish laws, installation and management of fish sanctuaries, and raising public awareness can be effective for the conservation of existing fisheries resources.

Agribusiness plays a key role in the sustainable economic development of rural poor by fulfilling daily needs. In South Asia, all the countries have a similar pattern of societies, resources, climates, practices, and people located close to each other. Crop cultivation, dairy production, fishery, and forestry are the main agribusiness sectors for trading agricultural produce in markets. In contrast, factors (i.e., global warming due to climate change, natural calamity, environmental pollution, unsafe foodstuff, labor unavailability, marketing limitations, and financial crisis) are responsible for a serious fatal to agribusiness activities. Unless we uproot challenges, agribusiness cannot contribute effectively to the economy of developing nations in South Asia. Thus, future strategies may be standing on contemporary scientific research approaches on crop science, restoring resources, controlling food quality, introducing modern types of machinery, best marketing practices, and inclusive financing.

This research aimed to find out the monthly variation in the gut contents of Nandus nandus. It was conducted in Kawadighi Haor of Sylhet division, Bangladesh from January to December, 2014. Four types of zooplankton belonging to crustacea (9 genera), rotifera (6 genera), fish larvae (1 genera) and several genus of insects larvae and three orders of phytoplankton viz . Bacillariophyceae (2 genera), Chlorophyceae (6 genera), and Cyanophyceae (2 genera) were recorded from the guts. Chlorophyceae (3.14±0.49×103 cells/l) was the most abundant order among phytoplankton. Crustacea (6.00±0.62×103 cells/l) was the dominant group among the zooplankton. The total amount of stomach content was higher in March (17.7×10 3 cells/l), followed by September (17.35×103 cells/l) and July (16.95×103 cells/l). The lowest food content in the guts was observed in December (11.9×103 cells/l) which was much lower than the average food content (15.64±1.60×103 cells/l). Based on the findings, it can be inferred that N. nandus preferred zooplankton the most, although feeding on both phytoplankton and zooplankton. The findings of this study are predicted to be significant in the management and conservation through domestication of near threatened N. nandus in open waters of Bangladesh paving the way for aquaculture in captivity.

The present study analyzes the market access of the biggest fish market at Chattogram coastal region of Bangladesh affected by COVID-19. The food chain was reduced locally, regionally, and globally as supply chains were disturbed and international seafood exports were halted for a certain period. For data collection several qualitative data collection tools, such as individual interviews as well as secondary document analysis were employed. To realize the overarching aim of this research the whole market system was analyzed including the supplier, wholesaler, retailer, as well as the consumer of the domestic market in the Chattogram district. The result shows that the pandemic slowed the supply and demand in the domestic fish market, and as a consequence the price of fish was distinctly reduced in the whole market system. The result highlights that the most affected stages of the supply chains are the supply quantity, the interval of the supply, and the quantity of fish sales. Furthermore, the principally affected stages of the demand chains are consumer demand and alternation in the preference of the consumer. To overcome such situation, this study recommends governmental financial support to trades to ensure the smooth flow of the supply and demand and create an alternative market system for the consumer. The pandemic and the measures to address the pandemic have created significant new challenges for market access and controlling pricing in domestic markets. Regularly engage of the policymakers are thus the prerequisite to overcome the compensation of trades and ensure food security in this sector.

Simple Summary Colistin is a widely used antibiotic against infections caused by extensively drug-resistant Gram-negative bacteria. It is critical to track and monitor the presence of mcr-like genes and colistin resistance to protect a last resort treatment against highly antibiotic-resistant bacteria. In the present study, the colistin resistance gene mcr-1 was investigated, and its in-silico functional analysis in Salmonella isolates was determined. Out of 100 chicken samples (liver and intestine), 82 Salmonella spp. were isolated and characterized. Antimicrobial sensitivity was determined using different antimicrobial agents. The isolates were characterized using PCR targeting genus-specific invA and mcr-1 genes followed by in-silico functional analysis. The majority of isolates (92.68%) was found highly resistant to colistin, which demonstrated the occurrence of the colistin resistance mcr-1 gene in Salmonella isolates of chicken origin in Bangladesh. The study also showed the in-silico functional analysis and phylogenetic relationship of the colistin resistance mcr-1 gene among Salmonella isolates. The findings of the present study highlight the increasing issue of transferable colistin resistance and call for immediate action and measures to review the imprudent use of colistin in poultry production systems in Bangladesh. Abstract Colistin (polymyxin E) is widely used in animal and human medicine and is increasingly used as one of the last-resort antibiotics against Gram-negative bacilli. Due to the increased use of colistin in treating infections caused by multidrug-resistant Gram-negative bacteria, resistance to this antibiotic ought to be monitored. The study was undertaken to elucidate the molecular mechanisms, genetic relationships and phenotype correlations of colistin-resistant isolates. Here, we report the detection of the mcr-1 gene in chicken-associated Salmonella isolates in Bangladesh and its in-silico functional analysis. Out of 100 samples, 82 Salmonella spp. were isolated from chicken specimens (liver, intestine). Phenotypic disc diffusion and minimum inhibitory concentration (MIC) assay using different antimicrobial agents were performed. Salmonella isolates were characterized using PCR methods targeting genus-specific invA and mcr-1 genes with validation for the functional analysis. The majority of the tested Salmonella isolates were found resistant to colistin (92.68%), ciprofloxacin (73.17%), tigecycline (62.20%) and trimethoprim/sulfamethoxazole (60.98%). When screened using PCR, five out of ten Salmonella isolates were found to carry the mcr-1 gene. One isolate was confirmed for Salmonella enterica subsp. enterica serovar Enteritidis, and other four isolates were confirmed for Salmonella enterica subsp. enterica serovar Typhimurium. Sequencing and phylogenetic analysis revealed a divergent evolutionary relationship between the catalytic domain of Neisseria meningitidis lipooligosaccharide phosphoethanolamine transferase A (LptA) and MCR proteins, rendering them resistant to colistin. Three-dimensional homology structural analysis of MCR-1 proteins and molecular docking interactions suggested that MCR-1 and LptA share a similar substrate binding cavity, which could be validated for the functional analysis. The comprehensive molecular and in-silico analyses of the colistin resistance mcr-1 gene of Salmonella spp. of chicken origin in the present study highlight the importance of continued monitoring and surveillance for antimicrobial resistance among pathogens in food chain animals.

SARS-CoV-2, a new coronavirus strain responsible for COVID-19 has emerged in Wuhan City, China and still continuing its worldwide pandemic nature. Considering the severity of the disease, a number of studies are underway, and full genomic sequences have already been released in the last few weeks to enable the understanding of the evolutionary origin and molecular characteristics of this virus. Bioinformatics analysis, satellite derived imaging data and epidemiological attributes were employed to investigate origin, immunogenic resemblance and global threat of newly pandemic SARS-CoV-2 including Bangladesh perspective. Based on currently available genomic information, a phylogeny study was employed focusing four types of representative viral proteins (spike, membrane, envelope and nucleoprotein) of SARS-CoV-2, HCoV-229E, HCoV-OC43, SARS-CoV, HCoV-NL63, HKU1, MERS-CoV, HKU4, HKU5 and BufCoV-HKU26. The findings clearly demonstrated that SARS-CoV-2 exhibited evolutionary convergent relation with previously reported SARS-CoV. It was also found that SARS-CoV-2 proteins were highly similar and identical to SARS-CoV proteins, though proteins from other coronaviruses showed lower level of similarity and identical patterns. The cross-checked conservancy analysis of SARS-CoV-2 antigenic epitopes showed significant conservancy with antigenic epitopes derived from SARS-CoV. The study also prioritized the temperature comparison through satellite imaging alongside compiling and analyzing the epidemiological outbreak information on the 2019 novel coronavirus based on several open datasets on COVID-19 (SARS-CoV-2) and discussed possible threats to Bangladesh., Highlights • Phylogenetic tree clearly demonstrating the ancestral origin and distant evolutionary relationships of the newly epidemic novel coronavirus SARS-CoV-2. • SARS-CoV-2 proteins showed highest level of similarity and identical patterns with SARS-CoV. • SARS-CoV-2 antigenic epitopes were significantly conserved with antigenic epitopes derived from SARS-CoV • COVID-19 poses a great burden across the world in terms of geographical coverage, occurrence of cases and death toll.

Antimicrobial resistance gene mcr-1 has been disseminated globally since its first discovery in Southern China in late 2015. However, the mcr-1 gene had not been identified previously in Salmonella isolates from poultry in Bangladesh. Here, we aimed to explore antimicrobial resistance gene mcr-1 in Salmonella isolates. Eighty two Salmonella isolates were isolated and characterized from suspected poultry specimens received from different zones of the country. A phenotypic disc diffusion assay with 15 antimicrobial agents was performed following CLSI standard. The disk diffusion assay showed that, all of the isolates presented high resistance to colistin (92.68%), oxytetracycline (86.59%), co-trimoxazole (76.83%), ciprofloxacin (73.17%) and enrofloxacin (65.85%). Further, randomly selected 10 Salmonella isolates were analyzed by polymerase chain reaction (PCR) targeting genus-specific invA and antimicrobial (colistin) resistance mcr-1 genes. Five were confirmed for the presence of the mcr-1 gene belonging to Salmonella spp. Further, sequencing followed by phylogenetic analysis revealed divergent evolutionary relation between the LptA and MCR proteins rendering them resistant to colistin. Three-dimensional homology structures of MCR-1 proteins were constructed and verified using different bioinformatics tools. Moreover, molecular docking interactions suggested that, MCR-1 and LptA share a similar substrate binding cavity which could be validated for the functional analysis. The results represent here is the first molecular and in silico analysis of colistin resistance mcr-1 gene of Salmonella in poultry in Bangladesh, which may emphasize the importance of the study on antibiotic resistance genes requiring for national monitoring and strategic surveillance in the country.

Recently a new coronavirus strain, COVID-19 has emerged in Wuhan City, China which cause disease and in many cases deaths to humans. Considering its severity a number of works are working on it and full genomic sequences has already released in the last few weeks to understand the evolutionary origin and molecular characteristics of this virus. Based on currently available genomic information a phylogenetic tree was constructed from four types of representative viral proteins (Spike, Membrane, Envelope and Nucleoproetin) of COVID-19, HCoV-229E, HCoV-OC43, SARS-CoV, HCoV-NL63, HKU1, MERS-CoV, HKU4, HKU5 and BufCoV-HKU26 clearly demonstrated that the ancestral origin and distant evolutionary relation of newly epidemic novel coronavirus (COVID-19). It had been found that COVID-19 was evolutionary related to SARS-CoV. It was also found that COVID-19 proteins were almost more than ninety (90%) similar and identical with SARS-CoV proteins. The cross-checked conservancy analysis of COVID-19 antigenic epitopes showed significant conservancy with SARS-CoV proteins. VaxiJen server reveal almost 100% immunogenic potential of four viral proteins with COVID-19. In this article, we present an effort on molecular evolutionary analysis, temperature comparison and compile and analyze epidemiological outbreak information on the 2019 novel coronavirus based on the several open datasets on COVID-19 (SARS-COV-2) and possible threat to Bangladesh.Authors Md Bashir Uddin and Mahmudul Hasan contributed equally to this work

In this study, hourly shift of green tide (GT) in the Yellow Sea (YS) during summer of 2015 and 2016 is investigated using Geostationary Ocean Color Imager-based normalized difference vegetation in...

Land masking of Synthetic Aperture Radar (SAR) images is generally accomplished by applying either archived shoreline databases or image segmentation. However, those methods cannot be solely applied to geographical areas complicated with many small islands and exposed rocks. Therefore, we have proposed a new procedure where Sobel edge extraction is applied to detect the edges of all objects from KOMPSAT-5 X-band SAR images, followed by a merging process with the edges from the land objects based on Electronic Navigational Chart (ENC) coastlines. Using the land mask data, geometrically corrected SAR images were masked before applying a ship detection algorithm. This land masking procedure was applied to several images covering different areas of the Korean Peninsula. The results show that land targets such as newly constructed and natural objects were also masked, and thus did not create false alarms during ship detection. Therefore, this method can be used to assist precise ship detection using SAR images in coastal waters.

In this paper, we have proposed a method of sea fog prediction using model sea surface wind (SSW) data and hourly optical satellite data with 500 m spatial resolution. Three sea fog cases in the Ye...

Foot and mouth disease (FMD) is a highly contagious and devastating viral disease among all cloven-footed animals. In Bangladesh, the disease is endemic, with outbreaks occurring throughout the year in the haor regions. Thus, the FMD outbreaks impact livelihoods in the haor area and are of great concern. Therefore, a cross-sectional study was undertaken to evaluate the prevalence, distribution, and risk factors for clinical FMD in some selected areas of haor in Sylhet division of Bangladesh. We examined 1,388 cattle, of which 343 were clinically affected with FMD (prevalence 24.71%, CI95% = 22.44 - 26.98) during the period from July 2017 through June 2018. Though production loss was observed, no mortality was recorded in the infected animals. The data article shows the spatial distribution of FMD prevalence. The temporal pattern indicates a higher number of FMD cases in June (47.01%, CI95% = 38.97 - 55.07). The gender was found associated (OR = 2.98; p < 0.001) with the potential risk of FMD occurrence through univariate analysis. Besides, indigenous breeds of cattle (OR = 2.83; p < 0.001) are found to be more susceptible to FMD compared to exotic and crossbreeds. The risk factors identified in this article will serve as a baseline for the development of risk based FMD control program in future.

Synthetic Aperture Radar (SAR) images contain different types of noises which restricts its wide application for the ocean surveillance. Therefore, this study focuses on removing several types of noises from SAR images. At first images were Fourier transformed to obtain frequency domain. Then, sidelobe noises from KOMPSAT-5, and scalloping and thermal noises from Sentinel-1 images were masked out by applying low-pass filter on the frequency domain. Then pixels affected by azimuth ambiguity in KOMPSAT-5 images were determined based on the distance and comparative brightness of the detected ships, and removed accordingly. This method is applied on 4 KOMPSAT-5 images and validated with the visual detection results of ships. The ship detection results without applying noise removal contains up to 59.26% false detections which were fully removed by the proposed method. Thus, the proposed noise reduction scheme has improved the accuracy of ship detection. Further improvement of the algorithm using more images is in progress.

This is a short summary of a published work on Synthetic Aperture Radar (SAR)-based land masking for ship detection after applying little modification in the original process [1]. The land masking in SAR images is commonly done by using either archived shoreline databases or an image segmentation which cannot appropriately masks all of the very small islets and exposed sea rocks in the coastal regions of Korean Peninsula. Therefore, in previous work coastline maps from Electronic Navigational Chart (ENC) were just used to retain the land objects from all extracted objects of KOMPSAT-5 images. In this study the method [1] is further improved by applying the ENC-based topography data at various depths which can also mask small sea rocks submerged just beneath the sea surface. Thus, this improved method of land masking could be useful for precise ship detection in SAR images, especially for the geographically complicated coastal regions with many small islets, exposed and submerged sea rocks like Korean Peninsula.

The inadequate supply of tilapia seed mostly fingerling which consider as the secured stock because of lower mortality rate is considered as one of the major present constraints to the development of the culture industry in annual flooded region of haor in Bangladesh. The floating bamboo net-hapa nursery system was observed to be very efficient in the mass production of tilapia fingerlings at haor water body in Sunamganj district, Bangladesh. This system was therefore, recommended for small-scale (artisanal) commercial operators consisting of fishermen families mostly involvement of women in order to uphold their socio economic contribution and hasten development of haor communities. The research was conducted by three treatments with three replicates each. It was found that treatment I showing stocking density of 750/m 2 with FCR and SGR were 1.14 ± 0.038 a and 10.55 ±0.103 a respectively was found to be the most favorable treatment among all. But while considering the cost benefit ratio treatment II found better for commercial aquaculture as the survival rate was higher in treatment II. Besides the treatment with moderate stocking rate of 900/m 2 found to be most profitable with Tk. 793.12±67.73 b while in treatment I (stocking density 750/m 2 ) and treatment III (stocking density 1050/m 2 ) the net profit were 582.45 ± SD 88.75 a and Tk. 655.04 ±51.76 ab , respectively. As in the commercial production the increasing in stocking density also increase net profit with the same unit area and resources. But in small scale farming like tilapia fingerling production not only profit but also investment capability need to be take into consideration. The cost-benefit ratio found in this study showed that in treatment I, II and III the benefit-cost ratio were 2.17:1, 2.36:1 and 1.99:1 respectively which indicate a moderate stocking density of treatment II is most profitable. It was emphasized that the operational and managerial skills of the culture operators in fingerling production account largely to the production cost minimizing and profitability as well.

Climate change is the burning issue of the present world and considered as a social fabrics. Present study was carried out at Sitakunda coast, Chittagong and aimed to assess the trend of climate change and identify its impact on coastal fisheries. Meteorological data for assessing climate change trend from 1980 to 2010 were collected from meteorological department and primary data from extensive field survey to identify the climate change impact on fisheries resource. Data revealed that seasonal pattern of meteorological parameters i.e. temperature and rainfall has been changing for past thirty one years. The fisheries resources of Sitakunda coast have been declined gradually for the past thirty one years as a consequence of continuous change in the climatic pattern.