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The rapid increase in aquaculture over the last several decades has led to concerns about the environmental impact of fish feeds relying on marine resources for fishmeal (FM). We aim to assess Nannochloropsis sp. QH25 co-product as a viable and sustainable replacement for FM in juvenile rainbow trout, Oncorhynchus mykiss, feeds. We formulated four experimental diets: a reference (FM based), 33N, 66N, and 100N diet (33%, 66%, and 100% co-product replacement). Rainbow trout were randomly assigned to one of 16 tanks and randomly assigned an experimental diet to consume throughout the experiment (64 days total), with four replicate tanks per diet. We compared the phosphorus (P) and nitrogen (N) digestibility, emissions, and growth between diets and, compared six environmental impacts (biotic resource use (BRU), global warming potential (GWP), water use, land use, marine eutrophication potential (MEP), and freshwater eutrophication potential (FEP)) of each diet. Our results indicate that replacing FM with co-product did not significantly alter growth. P digestibility of the experimental and reference diets was comparable. BRU conversion ratio was significantly lower in the experimental diets. However, there were significantly higher water and land use conversion ratios but insignificantly higher results in GWP, MEP, and FEP between the reference and 100N diet.

Integrated multi-trophic aquaculture, or IMTA, attempts to reduce or eliminate nutrient loading by introducing lower trophic organisms to consume waste matter. These organisms should be capable of consuming bottom detritus with dissolved and particulate organic matter such as feces and unconsumed feed from upper trophic species. The viability of sea cucumber integration into land-based aquaculture production facilities was investigated and discussed. The focus of the study was on the role of the sea cucumber as an ecosystem service. Consumption of nutrient-loaded waste is essential in reducing eutrophication and maintaining an ecological balance. I worked with Kauai Sea Farm’s (KSF) Dave Anderson (MAS MBC ’16), investigated and compiled the most recent findings in integrating sea cucumbers into their aquaculture farm at Nomilo Fishpond with a focus on sediment analysis and comparison of biomass of sea cucumbers used in this study.The primary goal of this preliminary study was to investigate the potential benefit of integrating sea cucumbers into existing aquaculture systems to clean up and reduce waste and at the same time improve environmental outcomes. This study highlights the viability of sea cucumber integration into land-based aquaculture farms, which addresses the value of waste reprocessing,and will significantly impact the future success of aquaculture farms.Please see media created in support of this project here: https://storymaps.arcgis.com/stories/13539350ebe648baa3b3ab1a1fb61e8a

The global seaweed aquaculture industry is rapidly expanding due to the diversity of applications and sustainability benefits. Despite its global historical and cultural significance, seaweed remains underutilized in Western diets. This project investigates barriers to the culinary use of domestically-farmed seaweed in the United States, focusing on chefs' perceptions and knowledge gaps. Through collaboration with chefs and seaweed farms, the project developed educational resources and recipes to showcase the culinary versatility of eight seaweed species. The findings highlight challenges in seaweed accessibility and consumer acceptance, proposing targeted educational initiatives to enhance the domestic seaweed market and promote its culinary adoption.Please see media created for this project here: https://tinyurl.com/5n88mk8n

The blue economy is an area of growing investment and evolution across industries, governments, and communities. The rising global population coupled with rapid development in technology and trade has spurred governments across the world to look to the ocean for new sources of economic growth. While the ocean has historically been seen as an endless source of protein and extractive resources, the impacts of climate change are revealing the fallacy of this long-held assumption. Ocean acidification, warmer temperatures, and rising sea levels are resulting in habitat and biodiversity loss, extreme weather patterns, and changes to fish stock compositions and migration patterns. As a result of these changes, it is increasingly important to ensure a sustainable coexistence between humans and marine ecosystems. By developing a blue economy that prioritizes not only economic growth, but also the health of the environment and the livelihoods of local communities, it is possible to build a lasting blue economy for generations to come. The following paper analyzes existing blue economy frameworks utilized around the world to inform a model that assesses the feasibility of implementing blue economy programs in U.S. National Marine Sanctuaries.

Blood cockle sampling and water quality monitoring were conducted monthly between September 2011 and June 2013 at four blood cockle aquaculture farms situated along the Selangor coast, of Malaysia. Histological observations of the gonads were performed to identify male and female blood cockles. The maturation of gonadal tissue was evaluated, and the relationship between the maturation status of blood cockles and water quality factors, such as salinity and chlorophyll a concentration, was examined at each station. Mature and spawning male cockles were present year-round at all stations except at Station C, where males were more susceptible to the influence of the estuary. Females exhibited a distinct seasonal change in gonadal tissue compared with males, with a higher proportion of spent-stage individuals during the dry season. In addition, the number of immature individuals, for which it was difficult to distinguish between males and females, increased during that period. These results showed that spawning activity on the Selangor coast is more prominent during the rainy season and less pronounced during the dry season. The relationship between salinity, chlorophyll a concentration, and the gonadal tissue maturation stage of the cockle was identified. These findings reveal that sexual maturation progressed in brackish water with a salinity of approximately 28 in both males and females. As salinity decreased to less than 25, the proportion of immature and spent-stage individuals that released sperm or eggs increased. Additionally, immature individuals' percentage increased when chlorophyll a concentration was low ( KEY WORDS: sexual maturation, blood cockle, Tegillarca granosa, Selangor, Malaysia, INTRODUCTION Also known as Anadara granosa (Linnaeus, 1758), Tegillarca granosa (Linnaeus, 1758) is a blood cockle. It is morphologically defined by approximately 18 ribs and numerous nodules on the shell [...]

Globalization of fishery products is playing a significant role in shaping the harvesting and use of aquatic foods, but a vigorous debate has focused on whether the trade is a driver of the inequitable distribution of aquatic foods. Here, we develop species-level mass balance and trophic level identification datasets for 174 countries and territories to analyze global aquatic food consumption patterns, trade characteristics, and impacts from 1976 to 2019. We find that per capita consumption of aquatic foods has increased significantly at the global scale, but the human aquatic food trophic level (HATL), i.e., the average trophic level of aquatic food items in the human diet, is declining (from 3.42 to 3.18) because of the considerable increase in low-trophic level aquaculture species output relative to that of capture fisheries since 1976. Moreover, our study finds that trade has contributed to increasing the availability and trophic level of aquatic foods in >60% of the worlds countries. Trade has also reduced geographic differences in the HATL among countries over recent decades. We suggest that there are important opportunities to widen the current focus on productivity gains and economic outputs to a more equitable global distribution of aquatic foods.

The global population consumes more seafood from aquaculture today than from capture fisheries and although the aquaculture industry continues to grow, both seafood sectors will continue to be important to the global food supply into the future. As farming continues to expand into ocean systems, understanding how wild populations and fisheries will interact with farms will be increasingly important to informing sustainable ocean planning and management. Using a spatially explicit population and fishing model we simulate several impacts from ocean aquaculture (i.e., aggregation, protection from fishing, and impacts on fitness) to evaluate the mechanisms underlying interactions between aquaculture, wild populations and fisheries. We find that aggregation of species to farms can increase the benefits of protection from fishing that a farm provides and can have greater impacts on more mobile species. Splitting total farm area into smaller farms can benefit fishery catches, whereas larger farms can provide greater ecological benefits through conservation of wild populations. Our results provide clear lessons on how to design and co-manage expanding ocean aquaculture along with wild capture ecosystem management to benefit fisheries or conservation objectives.

Mucosal barriers are gatekeepers of health and exhibit homeostatic variation in relation to habitat and disease. Mucosal Mapping technology provides an in‐depth examination of the dynamic mucous cells (MCs) in fish mucosal barriers on tangential sections, about 90° from the view of traditional histology. The method was originally developed and standardized in academia prior to the establishment of QuantiDoc AS to apply mucosal mapping, now trademarked as Veribarr™ for the analysis of skin, gills and gastrointestinal tracts. Veribarr™ uses design‐based stereology for the selection and measurement of cell area (size) (μm2), the volumetric density of MCs in the epithelium (MCD, amount of the epithelia occupied by MCs, in %) and the calculated abundance of the MCs (barrier status or defence activity). MC production was mapped across the skin and gill epithelia in 12 species, discovering that gills consistently have two distinct groups of MCs, one on the lamellae where MCs are few and small and one on the filament where MCs are larger and more abundant. MCs were usually much larger in the skin than in the gills, with the latter requiring fewer and smaller cells for adequate respiration. The difference observed between MCs in gill lamella and gill filament is likely a result of functional demands. In addition, our findings also highlight a variation in the mucosal parameters between the species skin, which cannot be explained by the weight differences, and a potential link between MC distribution and species‐specific lifestyles in the gill lamella. This diversity necessitates the development of species and tissue site‐specific reference intervals for mucosal health evaluation. Mucosal bivariate reference intervals were developed for MC production, including size (trophy) and calculated defence activity (plasia) in the skin and gills of Atlantic salmon, to contrast new measurements against historical data patterns. The application of mucosal reference intervals demonstrates that stress from parasites and treatments can manifest as changes in mucosal architecture, as evidenced by MC hypertrophy and hyperplasia within the gill lamellae. These reference intervals also facilitate comparisons with wild Atlantic salmon, revealing a somewhat higher MC level in farmed salmon gill lamellae. These findings suggest that MC hyperplasia and hypertrophy in the gills are stress/environmental responses in aquaculture. They also advocate for developing specific mucosal bivariate homeostatic reference intervals in aquaculture to improve fish health and welfare across all farmed species. [ABSTRACT FROM AUTHOR]

Edwardsiella piscicida is an emerging bacterial pathogen and the aetiological agent of edwardsiellosis among cultured and wild fish species globally. The increased frequency of outbreaks of this Gram‐negative, facultative intracellular pathogen pose not only a threat to the aquaculture industry but also a possible foodborne/waterborne public health risk due to the ill‐defined zoonotic potential. Thus, understanding the role of temperature on the virulence of this emerging pathogen is essential for comprehending the pathogenesis of piscine edwardsiellosis in the context of current warming trends associated with climate change, as well as providing insight into its zoonotic potential. In this study, significant temperature‐dependent alterations in bacterial growth patterns were observed, with bacterial isolates grown at 17°C displaying higher peak growth sizes, extended lag times, and slower maximal growth rates than isolates grown at 27or 37°C. When E. piscicida isolates were grown at 37°C compared to 27 and 17°C, mass spectrometry analysis of the E. piscicida proteome revealed significant downregulation of crucial virulence proteins, such as Type VI secretion system proteins and flagellar proteins. Although in vivo models of infection are warranted, this in vitro data suggests possible temperature‐associated alterations in the virulence and pathogenic potential of E. piscicida in poikilotherms and homeotherms. [ABSTRACT FROM AUTHOR]

Background: The salmonid pathogen Flavobacterium psychrophilum poses a significant economic threat to global aquaculture, yet our understanding of its genetic and phenotypic diversity remains incomplete across much of its geographic range. In this study, we characterise the genetic and phenotypic diversity of 70 isolates collected from rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta m. fario) from fish farms in the Czech Republic between 2012 and 2019 to compare their genomic content with all draft or complete genomes present in the NCBI database (n = 187). Results: The Czech isolates underwent comprehensive evaluation, including multiplex PCR-based serotyping, genetic analysis, antimicrobial resistance testing, and assessment of selected virulence factors. Multiplex PCR serotyping revealed 43 isolates as Type 1, 23 as Type 2, with sporadic cases of Types 3 and 4. Multi-locus sequence typing unveiled 12 sequence types (ST), including seven newly described ones. Notably, 24 isolates were identified as ST329, a novel sequence type, while 22 were classified as the globally-distributed ST2. Phylogenetic analysis demonstrated clonal distribution of ST329 in the Czech Republic, with these isolates lacking a phage sequence in their genomes. Antimicrobial susceptibility testing revealed a high proportion of isolates classified as non-wild type with reduced susceptibility to oxolinic acid, oxytetracycline, flumequine, and enrofloxacin, while most isolates were classified as wild type for florfenicol, sulfamethoxazole-trimethoprim, and erythromycin. However, 31 isolates classified as wild type for florfenicol exhibited minimum inhibitory concentrations at the susceptibility breakpoint. Conclusion: The prevalence of the Czech F. psychrophilum serotypes has evolved over time, likely influenced by the introduction of new isolates through international trade. Thus, it is crucial to monitor F. psychrophilum clones within and across countries using advanced methods such as MLST, serotyping, and genome sequencing. Given the open nature of the pan-genome, further sequencing of strains promises exciting discoveries in F. psychrophilum genomics. [ABSTRACT FROM AUTHOR]

This study provides a comprehensive summary of the findings regarding the application and diagnostic efficacy of droplet digital PCR (ddPCR) in detecting viral and bacterial pathogens in aquaculture. Utilizing a systematic search of four databases up to 6 November 2023, we identified studies where ddPCR was deployed for pathogen detection in aquaculture settings, adhering to Preferred Reporting Items for Systematic Reviews and Meta‐analysis of Diagnostic Test Accuracy guidelines. From the collected data, 16 studies retrieved, seven were included in a meta‐analysis, encompassing 1121 biological samples from various fish species. The detection limits reported ranged markedly from 0.07 to 34 copies/μL. A direct comparison of the diagnostic performance between ddPCR with quantitative PCR (qPCR) proved challenging due to limited data, thus only a pooled sensitivity analysis was feasible. The results showed a pooled sensitivity of 0.750 (95% confidence interval [CI]: 0.487–0.944) for ddPCR, compared to 0.461 (95% CI: 0.294–0.632) for qPCR, with no statistically significant difference in sensitivity between the two methods (p = .5884). Notably, significant heterogeneity was observed among the studies (I2 = 93%–97%, p < .01), with the year of publication significantly influencing this heterogeneity (p < .001), but not the country of origin (p = .49). No publication bias was detected, and the studies generally exhibited a low risk of bias according to QUADAS‐C criteria. While ddPCR and qPCR showed comparable sensitivities in pathogen detection, ddPCR's capability to precisely quantify pathogens without the need for standard curves highlights its potential utility. This characteristic could significantly enhance the accuracy and reliability of pathogen detection in aquaculture. [ABSTRACT FROM AUTHOR]

This study explored how increased water turbidity in open-aquaculture ponds as a result of enhanced fertilization influences piscivorous bird assemblages and predation pressure on fish. Fertilization treatments were applied to 24 earth-bottom ponds, and bird assemblages, visitation frequencies, diversities and predation rate responses were compared at species richness and across four functional group scales during six months. Bird visitation frequency, species richness and functional diversity increased around unfertilized ponds, especially for large wading birds. Fertilization and bird species richness were each negatively related to bird predation rate, whereas functional diversity was positively associated with predation rate regardless of pond fertilization. Furthermore, predation rate reduced in response to pairwise interactive effects of fertilization and functional group identity, but increased with fertilization's respective interaction with functional diversity and visitation frequency. Contrastingly, species richness showed no interactive effect with fertilization or visitation rate. Thus, in applying enhanced pond water fertilization as a mitigation measure for controlling and tracking damage impact caused by piscivorous birds, it is potentially more beneficial to adopt a bird functional rather than species-based approach, given the observed higher sensitivity of functional diversity in predicting predation rates. The findings present novel, farmer-centered and affordable strategies for piscivorous problem-bird control toward sustainable aquaculture. [ABSTRACT FROM AUTHOR]

Global increase in aquaculture production has created a need to reduce its environmental impacts. Nutrients could be recycled especially at land-based recirculating aquaculture systems (RAS) by cultivating green microalgae in aquaculture effluent. However, microalgae are difficult to harvest. As a multi-trophic solution, mussels could be used in harvesting microalgae. We tested three European freshwater mussels (duck mussel Anodonta anatina, swan mussel A. cygnea, and swollen river mussel Unio tumidus) for filtering two common green microalgae (Monoraphidium griffithii and Selenastrum sp.) grown in RAS effluent. Mussels decreased microalgal concentrations in the tanks 42–83% over three consecutive trials. Algal concentrations at the end of each trial were lowest for both microalgae in tanks containing Anodonta mussels. Clearance rates were higher for Anodonta mussels than for U. tumidus. Mussels biodeposited more microalgae to tank bottoms when M. griffithii was filtered. Ammonium concentration decreased or did not change in tanks with M. griffithii, but increased in tanks containing Selenastrum sp. These results suggest that of the tested species Anodonta mussels and M. griffithii show best potential for RAS effluent bioremediation application. We conclude that a co-culture of microalgae and unionid mussels could be used for recycling nutrients in aquaculture. [ABSTRACT FROM AUTHOR]

The mortality of Atlantic salmon is one of the main challenges to achieving its sustainable production. This sector benefits from generating many data, some of which are collated in a standardized way, on a monthly basis at site level, and are accessible to the public. This continuously updated resource might provide opportunities to monitor mortality and prompt producers and inspectors to further investigate when mortality is higher than expected. This study aimed to use the available open-source data to develop production cycle level dynamic linear models (DLMs) for monitoring monthly mortality of maricultured Atlantic salmon in Scotland. To achieve this, several production cycle level DLMs were created: one univariate DLM that includes just mortality; and various multivariate DLMs that include mortality and different combinations of environmental variables. While environmental information is not collated in a standardized way across all sites, open-source remote-sensed satellite resources provide continuous, standardized estimates. By combining environmental and mortality data, we seek to investigate whether adding environmental variables enhanced the estimates of mortality, and if so, which variables were most informative in this respect. The multivariate model performed better than the univariate DLM (P = .004), with salinity as the only significant contributor out of 12 environmental variables. Both models exhibited uncertainty related to the mortality estimates. Warnings were generated when any observation fell above the 95% credible interval. Approximately 30% of production cycles and more than 50% of sites experienced at least one warning between 2015 and 2020. Occurrences of these warnings were non-uniformly distributed across space and time, with the majority happening in the summer and autumn months. Recommendations for model improvement include employing shorter time periods for data aggregation, such as weekly instead of on a monthly basis. Furthermore, developing a model that takes hierarchical relationships into account could offer a promising approach. [ABSTRACT FROM AUTHOR]

A global inventory of extractive species mariculture in wave-exposed temperate waters shows that the longline is the technology used in more than 99% of the sites (Part 1 of this review). In this second part, I compare the static (longline at rest), quasi-static (tidal sea surface elevation, steady currents and mainline lifting operation) and dynamic (wind seas and swells) loading and motion of surface, semi-submerged and fully submerged longlines used to grow bivalves and kelp. This review is based on a hundred papers published on the subject mostly after 2010 and on simple analytical models used to illustrate the many compromises that must be made to ensure the survivability of the structure and the survival (retention), growth and quality of the cultured biomass. Surface longlines are unsuitable for fully exposed environments. To mitigate storm energy it is necessary to minimize the volume of surface buoys and submerge the mainline to the maximum depth possible. There is however a limit to minimizing the volume of surface buoys due to the uplifting of the mainline by currents. In the case of kelp, its optimal growing depth is within a few meters from the sea surface. This limitation can be partly circumvented by having the kelp float above the mainline. In the case of bivalves, mainline depth can be tens of meters below the sea surface. This comes with some disadvantages including difficulties in maintaining the delicate buoyancy balance, particularly for fully submerged longlines without legs, and reduced access to the mainline, particularly for fully submerged longlines with legs. Devices that allow autonomous or remote-controlled changes of mainline depth on a daily, occasional (husbandry and harvest operations) or seasonal basis have been tested but are not yet used commercially on longlines. [ABSTRACT FROM AUTHOR]

There is currently a strong drive to expand aquaculture further offshore cooccurring with a rapid change of the conditions under which this activity will be practiced due to climate change. At the dawn of these profound changes a global review of the current status of technologies used commercially to grow extractive species in wave exposed environments can serve as a benchmark for future developments. Part 1 of this paper presents a systematic inventory of commercial farms in temperate exposed waters. The study area includes 5 regions in the northern hemisphere and 3 regions in the southern hemisphere and covers entirely or part of 48 countries and territories. The inventory is based on 80+ high resolution aquaculture lease maps, most of them available as Internet Web-GIS applications, that cover the entire study area with the exception of a few countries. Exposed sites are first identified from these maps using simple wave fetch criteria and this preselection is then validated using climatological data on wave height and power density (energy flux). The number of sites and the leased area are tallied by region, country, species group and production method. The longline is the production method used in more than 99% of the sites inventoried. Longline design and farm layout in 28 of these sites are reviewed. With a few exceptions, semi-submerged or fully submerged designs are used (in some cases they have been for more than 30 years) while the information on farm layout is patchy. A review of structural damage and loss of cultured biomass due to hydrodynamic forces in commercial and experimental farms confirms that surface and semi-submerged longlines are more vulnerable to large storms than fully-submerged designs. [ABSTRACT FROM AUTHOR]

The farming of sturgeon to produce caviar is increasing globally, even though little is known about the welfare implications of aquaculture for these unique, long-living, and large animals. The use of non-lethal methods for egg harvesting is increasing, as these methods are thought to offer a more ethical alternative to traditional methods where the female is killed. However, these “non-lethal” methods raise significant welfare concerns including routine handling, surgical procedures, and painful procedures, and could potentially perpetuate suffering. Consequently, there is an urgent need for significant exploration and research into this field. This review presents and discusses some of the welfare concerns associated with producing caviar from sturgeon, including the traditional and non-lethal methods of egg harvesting and the concerns associated with rearing them in aquaculture systems. It concludes in stating that the welfare issues involved with non-lethal caviar production are too sizeable to warrant its description as an “ethical or humane” alternative to traditional caviar production. [ABSTRACT FROM AUTHOR]

Community composition in aquatic environments can be shaped by a broad array of factors, encompassing habitat conditions in addition to abiotic conditions and biotic interactions. This paper pertains to reaction–diffusion–advection predator–prey model featuring a variable predator habitat in advective environments, governed by a unidirectional flow. First, we establish the near‐complete global dynamics of the system. In instances where the functional response to predation conforms to Holling‐type I or II, we explore the uniqueness and stability of positive steady‐state solutions via the application of particular auxiliary techniques, the comparison principle for parabolic equations, and perturbation analysis. Furthermore, we obtain the critical positions at the upper and lower boundaries of the predator's habitat, which determine the survival of the prey irrespective of the predator's growth rate. Finally, we show how the location and length of the predator's habitat affect the persistence and extinction of predators and prey in the event of a small population loss rate at the downstream end. From the biological point of view, these results contribute to our deeper understanding of the effects of habitat on aquatic populations and may have applications in aquaculture and the establishment of protection zones for aquatic species. [ABSTRACT FROM AUTHOR]

In the past decade, the increasing distribution of pollutants in the aquatic environment has been observed, causing integrative effects on fish. Likewise, due to anthropogenic activities, the southern gulf of Lake Tana is an impacted region, and the production of Nile tilapia fish is reduced. For this reason, the aim of this study was to conduct a histopathological-based study of 48 Nile tilapia fishes' health status at the southern gulf of Lake Tana and aquaculture using a cross-sectional study from February 2023 to May 2023. The study evaluated the histopathology of the gill, liver, gonads, and spleen organs using descriptive statistics accompanied by a 2 × 2 contingency table and t-test analysis. During the study, different histological alterations were detected, and the numbers of fish affected by a specific histological alteration were presented as percentage prevalence; hence, from the total fish examined, hyperplasia (54.15%), followed by pigment deposits (52%), hemorrhage (50%), and immune cell infiltration (50%), respectively, were the most frequently detected alterations. However, Nile tilapias from the southern gulf of Lake Tana were 1.4 (odds ratio) times more likely to show histopathological alterations than those from aquaculture, although statistically, was not significant (p > 0.05). In addition, the study found the mean value of the fish index (95.3) and regressive indices of the gill (13.6), liver (14.8), and gonad (12.3); moreover, the inflammatory indices of the spleen organ (11.3) and mean severity grade value of the gill (2.35) and gonad (1.7) organs, respectively, were obtained from the southern gulf of Lake Tana, and all those values were significantly higher (p < 0.05) from this site as compared to the aquaculture. In general, it has been found that tilapias from the southern gulf of Lake Tana showed higher pathological severity as compared with aquaculture. Among the four target organs evaluated, liver organs were observed to be the most damaged, while gonads were the least impacted organs. Therefore, it has been concluded that tilapia fish are living in abnormal conditions, so to ensure a sustainable fishery, water pollutant sources from Bahirdar city must receive proper attention, and future studies should consider age differences, seasonal variation, and the detection of specific pollutants. [ABSTRACT FROM AUTHOR]

Background: Livestock and aquaculture feed rely heavily on cereals, fish meal, and plant proteins, but these ingredients are not fully utilized by animals, and alternative protein sources are needed due to rising demand, unstable resources, and high prices. However, plant-based materials contain phytic acid or phytate, making phosphorus less available to monogastric animals. Bacterial phytases can effectively release phosphorus from phytate in the digestive system, making them cost-effective and a potential alternative to traditional sources of phosphorus. Probiotics are helpful bacteria that have long been employed in food production and health-related products. Bioengineered probiotics are utilized to express and transmit native or recombinant molecules to the digestive tract's mucosal surface, thereby improving feed efficiency and health. Therefore, this study aimed to use a biologically engineered probiotic supplement containing phytase enzyme-producing lactic acid bacteria as a feed additive for livestock, poultry, and fish to address this issue. Results: The study involved multiple steps to engineer Lactobacillus lactis to produce the PHY protein for animal feed. These steps include identifying and designing primers for the phy gene, and phy gene was extracted from the pMNA1 plasmid by colony PCR and cloned in L. lactis, confirming the presence of the PHY protein through SDS-PAGE, and harvesting the product in granular form. The phy gene identified and isolated using PCR and inserted it into L. lactis, confirming the presence of the PHY protein through SDS-PAGE. The resulting product was harvested and used as animal feed for livestock, poultry, and fish. Conclusions: The development of biologically engineered probiotic supplements containing phytase enzyme can enhance the nutritional value and sustainability of animal production. More research and development in this field can lead to more effective and sustainable animal production practices, benefiting both producers and consumers of animal products. [ABSTRACT FROM AUTHOR]

Marine aquaculture has grown enormously in recent decades, and with it the competition for space suitable for aquaculture. These developments have limited the areas available for aquaculture and, in some cases, have become a barrier to expansion. In response, aquaculture operations have moved further away from the coast. This development has created a need for clearer and more robust approaches to more comprehensively describe and secure sites for aquaculture. This article reviews the law governing the siting of aquaculture operations. In particular, it assesses the role of the widely used term "offshore" in the Law of the Sea to see if there are any legal aspects that need to be considered in moving towards the use of more specific concepts. It also aims to inform scientific discussions and political and administrative processes on the law governing the identification, description, and siting of aquaculture operations. This will hopefully contribute to more sustainable and less conflicted long-term aquaculture development. [ABSTRACT FROM AUTHOR]

In 2017, the Chilean government through the Chilean Economic Development Agency (CORFO) (an agency under the Ministry of Economy) launched a public call for the execution of a Technological Program to adopt, adapt, and/or developing enabling technologies for the development of Ocean Aquaculture in places with high-energy (strong waves, winds and/or currents). The consortium of companies, technology centers, and universities led by Ecosea Farming (Ecosea), focused its efforts on aspects related to structural engineering, mooring systems, sensors, Internet of Things (IoT), and other integral components, as well as essential aspects of regulation and standards. On this last topic, intensive collaborative work was carried out between the technical teams of the Andrés Bello University, the Undersecretariat of Fisheries and Aquaculture (Subpesca), the National Fisheries and Aquaculture Service (Sernapesca), and CORFO, with the aim of gathering relevant information from international experience, and establishing the main differences between aquaculture traditionally developed in the fjords, coast, estuaries, and inland sea of southern Chile and aquaculture in the high seas - a practice not yet clearly defined and still indistinctly known as offshore or open ocean aquaculture. This document summarizes the main findings obtained and can be a useful guide for future experiences in other countries with important aquaculture developments. [ABSTRACT FROM AUTHOR]

Hubei Province is an important freshwater fish producer in China,and the freshwater aquaculture production has ranked first in the country for many years. The freshwater aquaculture varieties are diverse and the aquaculture technology is more advanced. In recent years,Micropterus salmoides aquaculture has flourished throughout the country,and the aquaculture production has increased year by year. Under the new opportunity of aquaculture development,based on fishery statistical data,this paper analyzed the current situation of Micropterus salmoides industry in Hubei Province,explored the problems existing in the industry,and proposed corresponding countermeasures for future development, in order to contribute to the transformation and upgrading of freshwater fisheries in Hubei Province. [ABSTRACT FROM AUTHOR]

The ability to impact the immune response of the host has been recognized as essential for the success of a virus during infection. A few groups of viruses can combine these immunomodulatory mechanisms with specific patterns of their own transcriptional and replication regulation to achieve persistence within the host long term. The Herpesvirales order is one of those groups and the resultant state is known as latency. Throughout the years, latency has been studied in many host‐herpesvirus models to attempt to understand the complex and profound effects of this state on the host's systems, and in the hopes of deciphering a way to eliminate the latent state from survivors of the primary infection. Most studies of herpesvirus latency have been conducted on mammalian host species, but this review summarizes the data available regarding herpesviruses in fish species and their latent state. As the field of aquatic animal health research continues to advance, the elucidation of these complex mechanisms will be crucial for disease control, prevention, and treatment. [ABSTRACT FROM AUTHOR]

Shellfish aquaculture can provide important ecosystem services to coastal communities, yet these benefits are not typically considered within the aquaculture permit review process. Resource managers have expressed interest in easy-to-use tools, based on robust science, that produce location and operation-appropriate values for beneficial services. These values need to be produced in a format that aligns with existing regulatory processes to facilitate seamless integration with permit review. The removal of excess nitrogen from coastal waters by shellfish farms is well documented in the literature and has been incorporated into nutrient management in the USA. Shellfish assimilate nitrogen into their tissue and shell as they grow, and this nitrogen is removed from the environment upon harvest. We have assembled a dataset of nitrogen concentration and morphometric measurements from farmed eastern oysters across the US Northeast, and adapted methodology used by existing nutrient management programs to quantify harvest-associated removal of nitrogen. Variability in oyster tissue and shell nutrient concentration was low within the dataset, and an assessment of farm location, ploidy, and three common cultivation practices (floating gear, bottom gear, no gear) suggested that a simple regression-based calculation could be applied across all farms within the region. We designed the new, publicly available online Aquaculture Nutrient Removal Calculator tool https://connect.fisheries.noaa.gov/ANRC/ based on this analysis, which uses inputs related to oyster size and harvest number to predict harvest-based nitrogen removal from an eastern oyster farm located within the geographic range of North Carolina to Maine, USA. The tool also produces a report that has been designed to integrate with the US Army Corps of Engineers public interest review process, and similar state-level permitting processes, and provides a succinct summary of the ecological services associated with nutrient removal in eutrophic locations, project-specific values, and citations supporting the calculation of those values. [ABSTRACT FROM AUTHOR]

Summary Emulsions are combinations of two‐phases of immiscible liquids, where one liquid is dispersed throughout the other liquid with the help of emulsifiers such as surfactants. Surfactants, which are emulsifiers composed of small amphiphilic molecules, have several drawbacks. These include being non‐biodegradable and releasing various chemical compounds into the environment. Consequently, they are not ideal for prolonged use. Solid particles can be an alternative candidate to stabilise emulsions, forming what are known as Pickering emulsions (PEs). It has shown that PEs exhibited greater encapsulation efficiency (EE) of other substances up to 98%, which is more than twice compared with that of surfactant‐stabilised emulsions. Due to its irreversible adsorption, PEs has been recognised in various industries such as cosmetics, food, biomedical and aquaculture which have potential in targeted drug and nutrient delivery to the fish, water management, feed enhancement and stress reduction in aquaculture species. Thus, this review will be discussing on (i) emulsion stability and performance, (ii) solid particles in stabilising Pickering emulsions, (iii) use of PEs in various industries, (iv) nanotechnology in PEs to optimise aquaculture, (v) potential of PEs as drug delivery in fish culture, (vi) PEs as agents in water quality management, and (vii) PEs as encapsulation of stress‐relieving compounds, (viii) PEs as fish and fish feed enhancer, (ix) innovations of chitosan‐based PEs from aquaculture by‐product, and (x) innovations of PEs from fisheries by‐product. This review would provide insight into future research on enhancing the sustainability and functionality of Pickering emulsions by exploring novel, environmentally friendly solid particles and incorporating advanced nanotechnology techniques to further improve Pickering emulsions stability. [ABSTRACT FROM AUTHOR]

Over the past decade, there has been a growing interest in common octopus aquaculture, prompted by several factors such as the increase in market demand, the decline in overall fisheries and the search for more sustainable food resources. Nevertheless, this interest has raised concerns about the potential impact of largescale production and intensified farming practices in the future. This study aims to establish a baseline understanding of the natural microbial communities that inhabit skin mucus of the common octopus, describe its core microbiota, and assess the impact of captive rearing on these communities and animal welfare. The skin microbiome of wild-captured octopuses was compared with that of reared in aquaculture using 16S ribosomal RNA metabarcoding. The findings show that the core microbiota of octopus mucosal skin is dominated by the phyla Bacteroidota and Pseudomonadota, with Aurantivirga, Pseudofulvibacter, and Rubritalea being the most abundant genera. Despite differences in abundance, the microbiota composition and diversity between wild and aquaculture octopuses were similar. Wild samples had an enrichment of Gammaproteobacteria, including potentially pathogenic species such as Vibrio spp., Photobacteriumswingsii, and Lactococcus garvieae, which were less prevalent or absent in aquaculture samples. KEGG functional pathways predictions indicated a higher enrichment in functional pathways related to xenobiotic remediation in wild samples, reflecting their need to adapt to a more variable and potentially contaminated environment. This is the first study to characterize the mucosal skin microbiome of the common octopus and to compare wild and aquaculture specimens. The results suggest that current aquaculture practices support animal welfare through the use of controlled hatchery environments and high-quality water conditions. These insights are valuable for the development of sustainable and responsible aquaculture practices, with the octopus microbiome serving as a potential biomarker for health status and animal welfare. [ABSTRACT FROM AUTHOR]

Effective and frequent inspections are crucial for understanding the ecological and structural health of aquaculture setups. Monitoring in turbid, shallow, and dynamic environments can be time-intensive, expensive, and with a certain level of risk. The use of monitoring techniques based on autonomous vehicles is an attractive alternative approach because these vehicles are becoming easier to use, cheaper and more apt to carry different sensors. In this study, we used an Autonomous Underwater Vehicle (AUV) equipped with interferometric side scan sonar to observe an aquaculture setup in the Belgain North Sea. The surveys provided information on the longlines and indicated that the mussel dropper lines touched the seabed, implying that mussel growth weighed the longlines down. The side scan imagery also captured significant scouring around the longline anchors and localized debris on the seabed, which is important information to ensure the long-term sustainability of the setup and impact on the seabed. The results show that observing mussel longlines in a turbid, shallow, and high-energy environment using an AUV is a viable technique that can provide valuable information. Thus, the present study provides key insights into the application of innovative uncrewed monitoring techniques and forms an important step towards efficient and sustainable management of offshore aquaculture setups. [ABSTRACT FROM AUTHOR]

\nHighlightsThe Bangiales are one of the most common seaweeds in sub-Antarctic and Southeastern Pacific upper intertidal habitats. Here we report records of an ‘olpidioid’ marine obligate parasite infecting Bangiales between 39°20′–41°44′S in the Southeastern Pacific for the first time. The disease resembles the ‘Olpidiopsis blight disease’ reported for farmed Bangiales in Japan and Korea and wild Pyropia from Scotland morphologically and developmentally. The Chilean isolate infects commercial Chilean laver or ‘luche’ (Porphyra sensu lato) and Bangia sensu lato from wild populations in the Southeastern Pacific. Phylogenetic markers (cox2, 18S) identify it as Olpidiopsis porphyrae. We relate the occurrence of this pathogen to both ‘luche’ fisheries in Chile and the potential consequences for its emergent aquaculture in the Southeastern Pacific. The parasite Olpidiopsis porphyrae (Oomycota) is reported in Chile and the Southeastern Pacific for the first time.O. porphyrae infects Chilean Porphyra and Bangia sensu lato.The prevalence of O. porphyrae is very variable between populations, and highly seasonal in a locality of Southern Chile.The parasite Olpidiopsis porphyrae (Oomycota) is reported in Chile and the Southeastern Pacific for the first time.O. porphyrae infects Chilean Porphyra and Bangia sensu lato.The prevalence of O. porphyrae is very variable between populations, and highly seasonal in a locality of Southern Chile. [ABSTRACT FROM AUTHOR]

Maintaining genetic diversity in cultured shellfish can be challenging due to high variance in individual reproductive success, founder effects, and rapid genetic drift, but is important to retain adaptive potential and avoid inbreeding depression. To support broodstock management and selective breeding in cultured Pacific oysters (Crassostrea (Magallana) gigas), we developed an amplicon panel targeting 592 genomic regions and SNP variants with an average of 50 amplicons per chromosome. Target SNPs were selected based on elevated observed heterozygosity or differentiation in Pacific oyster populations in British Columbia, Canada. The use of the panel for parentage applications was evaluated using multiple generations of oysters from a breeding program on Vancouver Island, Canada (n = 181) and families selected for Ostreid herpesvirus-1 resistance from the Molluscan Broodstock Program in Oregon, USA (n = 136). Population characterization was evaluated using wild, naturalized, farmed, or hatchery oysters sampled throughout the Northern Hemisphere (n = 189). Technical replicates showed high genotype concordance (97.5%; n = 68 replicates). Parentage analysis found suspected pedigree and sample handling errors, demonstrating the panel's value for quality control in breeding programs. Suspected null alleles were identified and found to be largely population dependent, suggesting population-specific variation impacting target amplification. Null alleles were identified using existing data without the need for pedigree information, and once they were removed, assignment rates increased to 93.0 and 86.0% of possible assignments in the two breeding program datasets. A pipeline for analyzing the amplicon sequence data from sequencer output, amplitools , is also provided. [ABSTRACT FROM AUTHOR]

Aquaculture, commonly conceived as "fish farming," includes the culture of anininls, plants, or other species in water. Although about 70% of Earth's surfnce is covered by water, aquaculture often uses much snialler spaces such as tanks, ponds, mceways, or aquatic enclosures to grow aquatic food, fiber, mid other resources. Theologically, humans are called to "protect and serve" (Gen. 2:15), and throughout the Bible, there nre calls to good stezoardship and cultivation while allowing for fruitfulness of other creatures. Biblically, fish are seen as God-created aquatic creatures, often used as food, with implications for wise stewardship (e.g., Psalm 8). At the present, many fisheries around the world are overfished. Sustainable nqunculture should address environmental, economic, and health concerns, and it could help reduce the stress on natural fisheries. As the fastest-growing protein sector, aquaculture now produces more seafood than the wild / mrvest of all the world 's oceans (now approximately 120 niillion metric tons per year). This promising and expanding field (approximately 6-8% growth per year over the last 50 years) includes extremely efficient converters of protein, micro- and nincro-algae (seaweeds) that con absorb unwanted wastes and clean the water, and filter feeders such as oysters and clams that Clear the water of algne and other particles, simultaneously contributing various eco-system services and habitat. Ongoing problems include pathogenic and related disease issues. environmental pollution in sulface waters, food st#ty, increasing automation utilization, potential genetic concerns, and the relatively recent start of modern aqua-culture (most nqunculture growth has occurred since 1970). This article addresses each of these hurdles, identifies areas of theological and ethical concern, and clarifies matters of interest to Christians and others, suggesting possible ways forzoard in this fast-growing but cliallenging field. [ABSTRACT FROM AUTHOR]

Aquaculture, the world's fastest-growing food production sector, is critical for addressing food security concerns because of its potential to deliver high-quality, nutrient-rich supplies by 2050. This review assesses the effectiveness of CRISPR/Cas9 genome editing technology in enhancing desirable traits in fish species, including growth rates, muscle quality, disease resistance, pigmentation, and more. It also focuses on the potential effectiveness of the technology in allowing precise and targeted modifications of fish DNA to improve desirable characteristics. Many studies have reported successful applications of CRISPR/Cas9, such as knocking out reproductive genes to control reproduction and sex determination, enhancing feed conversion efficiency, and reducing off-target effects. Additionally, this technology has contributed to environmental sustainability by reducing nitrogen-rich waste and improving the nutritional composition of fish. However, the acceptance of CRISPR/Cas9 modified fish by the public and consumers is hindered by concerns regarding public perception, potential ecological impacts, and regulatory frameworks. To gain public approval and consumer confidence, clear communication about the editing process, as well as data on the safety and environmental considerations of genetically modified fish, are essential. This review paper discusses these challenges, provides possible solutions, and recommends future research on the integration of CRISPR/Cas9 into sustainable aquaculture practices, focusing on the responsible management of genetically modified fish to enable the creation of growth and disease-resistant strains. In conclusion, this review highlights the transformative potential of CRISPR/Cas9 technology in improving fish traits, while also considering the challenges and ethical considerations associated with sustainable and responsible practices in aquaculture. [ABSTRACT FROM AUTHOR]

Artificial Intelligence (AI) and Machine Learning (ML) can assist producers to better manage recirculating aquaculture systems (RASs). ML is a data-intensive process, and model performance primarily depends on the quality of training data. Relatively higher fish density and water turbidity in intensive RAS culture produce major challenges in acquiring high-quality underwater image data. Additionally, the manual image annotation involved in model training can be subjective, time-consuming, and labor-intensive. Therefore, the presented study aimed to simulate fish schooling behavior for RAS conditions and investigate the feasibility of using computer-simulated virtual images to train a robust fish detection model. Additionally, to expedite the model training and automate the virtual image annotation, a process flow was developed. The 'virtual model' performances were compared with models trained on real-world images and combinations of real and virtual images. The results of the study indicate that the virtual model trained solely with computer-simulated images could not perform satisfactorily (mAP = 62.8%, F1 score = 0.61) to detect fish in a real RAS environment; however, replacing a small number of the virtual images with real images in the training dataset significantly improved the model's performance. The M6 mixed model trained with 630 virtual and 70 real images (virtual-to-real image ratio: 90:10) achieved mAP and F1 scores of 91.8% and 0.87, respectively. Furthermore, the training time cost for the M6 model was seven times shorter than that for the 'real model'. Overall, the virtual simulation approach exhibited great promise in rapidly training a reliable fish detection model for RAS operations. [ABSTRACT FROM AUTHOR]

Simple Summary: Natural feed attractants are regularly used in aquafeeds to improve their palatability but show a number of disadvantages related to their natural origin, such as inconsistent quality of the raw materials, variable availability, and their dependency from natural sources. Contrariwise, synthetic flavors obtained through standardized processes are emerging as novel, more sustainable and effective substitutes to natural ones. The aim of the present study was to evaluate the use of synthetic flavors as novel feed attractants in zebrafish (Danio rerio) diet. A multidisciplinary approach was used to evaluate the dietary effects of the tested flavors—two attractive and one repulsive—on fish feed intake and growth, as well as on appetite regulation, brain reward system, and reproductive performances. Both diets containing the attractive flavors enhanced zebrafish feed intake and growth, promoting the fish reproductive performances without affecting fish welfare. Having ingested more feed, fish were able to invest to a greater extent in high-metabolic-demanding processes such as growth and reproduction. Improving the feeding practices of aquaculture, especially obtaining a quick feeding response by the fish, is a critical aspect for aquafeed production to minimize both the economic and environmental impacts. The present study aimed to test over a six-month period different synthetic flavors in zebrafish (Danio rerio) as an experimental model. Specifically, two attractive and one repulsive synthetic flavors were added (1% w/w) to a specific zebrafish diet, which was administered to the fish during the whole life cycle (from larvae to adults), to evaluate their physiological responses, emphasizing fish welfare, feed intake, growth, reward mechanisms, and reproductive performances. Fish welfare was not affected by all tested flavors, while both attractive flavors promoted fish feed ingestion and growth. The results were supported by both molecular and immunohistochemical analyses on appetite-regulating neurohormonal signals, along with the influence of the feed hedonic properties induced by the brain reward sensation, as demonstrated by the dopamine receptor gene expression. Finally, the present study demonstrated that a higher feed intake also had positive implications on fish reproductive performances, suggesting a promising role of synthetic flavors for the aquaculture industry. In conclusion, the results highlighted the potential of synthetic flavors to improve fish feeding strategies by providing a consistent and effective alternative to traditional stimulants, thereby reducing dependence on natural sources. [ABSTRACT FROM AUTHOR]

Simple Summary: Aquaculture is presented as a viable solution to overfishing and the growing demand for marine products. This study investigates the rearing of rainbow trout (Oncorhynchus mykiss) in a recirculating system at 3000 m above sea level, in Copaquilla, northern Chile. A total of 5000 juvenile trout were transported from the Rio Blanco fish farm over 2100 km. For 20 months, growth parameters were evaluated, including specific growth rate, weight gain, feed conversion, survival, and Fulton's condition factor. The results indicated normal growth and good quality, confirming the feasibility of trout aquaculture at a high altitude. This suggests new opportunities for aquaculture in the Andean region of northern Chile. Given the overexploitation of fisheries and the growing consumption of sea products, aquaculture is emerging as an alternative to meet the demand for protein at regional, national, and global levels. In northern Chile, the foothills of the Andes offer an opportunity for sustainable economic diversification. In this study, results of a rainbow trout (Oncorhynchus mykiss) culture in a recirculation system are presented, analyzing its growth and performance under altitude conditions. The research was carried out in Copaquilla, a small area in the foothills of northern Chile, 3000 m above sea level. Five thousand 15 g juvenile trout were acquired and transported by land from the Rio Blanco fish farm, successfully traveling more than 2100 km. During the 20-month-long culture, several growth parameters were evaluated, including specific growth rate, percentage of weight growth, feed conversion factor, survival, and Fulton's condition factor. All these parameters were within the normal growth range for trout, evidencing good-quality growth of the organisms. The results offer evidence that rainbow trout farming at 3000 m above sea level is viable and presents a viable performance, opening new opportunities for aquaculture in northern Chile. [ABSTRACT FROM AUTHOR]

Simple Summary: Freshwater mussels create habitat, filter water, and enhance food webs, but they are also among the world's most imperiled taxa. Conservation efforts largely rely on captive propagation in which mussels are grown in protected aquaculture environments (hatcheries) for later release. Recent evidence has highlighted the importance of pathogens in population losses of freshwater mussels. In response to ongoing mass mortality events of freshwater mussels in the Upper Tennessee River Basin in Virginia and Tennessee, USA, we conducted a multi-year study to document viruses across multiple restoration sites and compare them to viruses in mussels from the hatchery. Viral communities changed greatly after mussels were released. Of the 681 viruses of the 27 families we documented, only 20 viruses were found exclusively in hatchery mussels, compared to 451 viruses found only in mussels stocked to the wild. After release, mussels rapidly acquired new viruses, and the number of viruses increased steadily over time. These findings have implications for how mussel introduction programs might be managed for greater success, for example, by incorporating acclimatization periods prior to full release. Freshwater mussels (order: Unionida) are highly imperiled globally and are increasingly the focus of captive propagation efforts to protect and restore wild populations. The Upper Tennessee River Basin (UTRB) in Virginia is a freshwater biodiversity hotspot hosting at least 45 of North America's ~300 species of freshwater mussels, including 21 threatened and endangered species listed under the U.S. Endangered Species Act. Recent studies have documented that viruses and other microbes have contributed to freshwater mussel population declines in the UTRB. We conducted a multi-year longitudinal study of captive-reared hatchery mussels released to restoration sites throughout the UTRB to evaluate their viromes and compare them to captive hatchery environments. We documented 681 viruses from 27 families. The hatchery mussels had significantly less viruses than those deployed to wild sites, with only 20 viruses unique to the hatchery mussels. After the hatchery mussels were released into the wild, their number of viruses initially spiked and then increased steadily over time, with 451 viruses in total unique to the mussels in the wild. We found Clinch densovirus 1 (CDNV-1), a virus previously associated with mass mortality events in the Clinch River, in all samples, but the wild site mussels consistently had significantly higher CDNV-1 levels than those held in the hatchery. Our data document substantial differences between the viruses in the mussels in the hatchery and wild environments and rapid virome shifts after the mussels are released to the wild sites. These findings indicate that mussel release programs might benefit from acclimatization periods or other measures to mitigate the potential negative effects of rapid exposure to infectious agents found in natural environments. [ABSTRACT FROM AUTHOR]

Antibiotics can be introduced from aquaculture facilities into marine sediments, where they may affect benthic communities and generate antimicrobial resistance (AMR). Antibiotics can be used in tandem with antiparasitics, and the effects of their combined usage could affect AMR patterns and transmit antibiotic resistance genes. This study compiles patterns of antibiotic and antiparasitic drug usage from 2016 to 2021 in British Columbia, New Brunswick, Newfoundland and Labrador, and Nova Scotia (Canada) and compares them internationally. There is an overall reduction in rates of antibiotic use per fish produced in Canadian aquaculture sites from 2016 to 2021. Compared to other salmon-producing countries, Canadian antibiotic rates per tonne of fish are lower than in Chile, but higher, on average, than in Norway and Scotland. Florfenicol (FLO) and oxytetracycline (OTC) are the prevalent antibiotics used in most salmon-producing countries, including Canada. We also note that <30% of sites used two drugs per year and <18% of sites used three drugs, with most of these sites using one antibiotic and one antiparasitic. There is an increase in FLO and a decrease use in OTC use in Canada, which could be positive environmentally considering FLO's lower dose and environmental persistence. The east and west coasts show comparable antibiotic rates, with an average rate of 78 mg/kg in BC and 76 mg/kg in the Atlantic provinces; however, they have differences in the type of antibiotic (average use of OTC: BC 38 mg/kg vs. Atlantic 214 mg/kg; average use of FLO: BC 40 mg/kg vs. Atlantic 10 mg/kg). Other distinctions between coasts include variation in the timing of treatments, with seasonal use in the Atlantic provinces (May–November) and year-round use in BC. This pattern is likely influenced by differences in water temperature and, subsequently, potential susceptibility to aquatic diseases. Disease prevalence and veterinarian choice/preferred treatments are factors that, we hypothesize, may impact treatment choice; however, additional information is required to adequately comment on this point. This data compilation includes spatial descriptions that could be used for area prioritization in future studies. [ABSTRACT FROM AUTHOR]

Some hosts harbor more parasites than others. Overdispersion of parasitism suggests that coevolution with parasites may be more important to the biology and ecology of certain species. We examined patterns of parasitism and host traits in fished decapod crustaceans, which are economically and ecologically important worldwide. Using a synthesis approach, we determine that host life history, including habitat, longevity, sociality, invasion history, and fisheries involvement, correlate with the number and type of parasite species harbored. Indicator species analysis revealed close relationships between decapods and certain parasite groups, including crabs with rhizocephalans and dinoflagellates; crayfish with mesomycetozoans, oomycetes, branchiobdellids, and fungi; lobsters with copepods and amoebae; and shrimp with viruses. In contrast, Nematomorpha and Nemertea appear to be under-represented and under-studied as parasite groups in decapods. Decapods that are commercially fished, aquacultured, introduced outside their native range, and/or exhibit parental care tend to have higher parasite species richness (PSR). Parasite richness also increases with how well-studied a host group is, which we addressed with a machine learning algorithm that predicts false negative associations. Geographic range is commonly positively correlated with parasite richness, however reliable ranges are not available for most decapod species, highlighting a significant future research need. Identifying patterns such as these increases our broad understanding of decapod disease ecology but also enabled us to develop a series of recommendations on how to focus future research, management, and aquaculture development efforts. [ABSTRACT FROM AUTHOR]

A self-exchange aquaculture vessel stands as an environmentally sustainable solution for fish farming, capitalising on seawater utilization and minimising the risk of fish escapes through the implementation of perforated culture tanks. This research aims to lay the groundwork for the conceptual design, modelling, and simulation analysis of such vessels, focusing on how near-bottom perforation placement affects flow field characteristics within the culture tank. This paper presents a computational study using Computational Fluid Dynamics (CFD) to analyse self-exchange aquaculture vessels under both head and beam current conditions. The solution of conservation equations governing tank hydrodynamics is achieved using an implicit unsteady second-order Eulerian (finite volume) technique on optimised trimmed meshes. Experimental and predicted values for the vessel model's total resistance were evaluated using uncertainty analysis, validating the numerical model. It was found that proper positioning of perforations near the bottom significantly enhances the synergistic effect of fluid within the culture tank and the mixing characteristics of the flow field. To enhance water circulation, it is recommended to install two or more rows of perforations on the sides of self-exchange aquaculture vessels. The coordination between perforation placement and vessel structure should be considered to determine the optimal layout. By offering valuable insights into the effects of perforation placement, this study contributes to the development of more efficient and environmentally friendly aquaculture practices. • Hydrodynamics of a tank on the self-exchange aquaculture vessel studied by numerical methods. • The jet-like effect in the perforated culture tank was explored. • The influence mechanism of perforation placement on tank hydrodynamics was revealed. • Well-placed perforations boost fluid linkage inside and outside the tank. [ABSTRACT FROM AUTHOR]

The effects of different dietary lipid levels on lipid accumulation, inflammatory response, serum bio-chemical index and histological features of intestine and hepatopancreas of O. macrolepis was experimentally evaluated in an eight-weeks study. Fish (initial weight 50.11 ± 2.86 g) were fed with five iso-nitrogenous diets (around 390 g/kg protein) varying with lipid level (5%, 7%, 9%, 11%, 13%, being LL5, LL7, LL9, LL11, and LL13 respectively) in triplicates. Results showed that the content of crude lipid in carcass and hepatopancreas were not affected by dietary lipid levels (P > 0.05). Serum ALT, TP, HDL-c and MDA, etc., were not significantly affected by diets (P > 0.05), while serum total antioxidant capacity in LL9 and LL11 groups were significantly higher than the other groups (P < 0.05). Histological features of hepatopancreas and intestine showed no significant difference among the five diets (P > 0.05), while the height of intestine villus showed the higher trend in LL9 compared with other groups. The relative expression of lipid metabolism related genes (ppar α, cpt-1α, fas, and hsl) and immune response related genes (tlr 22, nrf 2, tnfα, and il-γ) in the hepatopancreas of fish fed diets differing in their crude lipid levels were not significantly different (P > 0.05). The results suggested that a proper dietary lipid level of 9%--11% could maintain higher antioxidant and health status of adult O.macrolepis. [ABSTRACT FROM AUTHOR]

Protein deficiency is a major difficulty for human needs in the past few decades, while different types of aquatic species are rich in high quality protein. Therefore, aquaculture is considered as the main developing food production sector globally. Bacterial infections are the main problem for aquaculture, and their outbreaks have a great impact on productivity, and previously indiscriminate use of antibiotics to control them. However, the emergence of multidrug-resistant pathogens might lead to sudden infectious disease outbreaks resulting in serious economic loss. Immunostimulants application is an effective technique to protect and enhance the immune system of aquatic animals and therefore improve aquaculture production. Nutrient immunostimulants such as essential fatty acids, amino acids, vitamins, and minerals are the most important responsibility to improve aquaculture production, as well as the cost of this method, which is effective, non-toxic, and environment friendly. These nutrient immunostimulants are supportive to increase the immune system, antioxidant, antiinflammatory, and infection resistance of aquatic animals. In addition, nutritional feed additives improved feed palatability and the excellence of aquatic products and also enhance gut functions. Some information is available on nutrient immunostimulants in aquaculture applications, and this review provides information on different kinds of nutritional administration used in aquaculture to enhance positive impacts on aquatic animals' health as well as feed quality development. This review will provide theoretical references for the application of nutrient immunostimulants in aquatic feeds. [ABSTRACT FROM AUTHOR]

Tetrodotoxin (TTX) is a potent neurotoxin firstly discovered in the ovary of pufferfish. The genetic basis of voltage-gated sodium channel resistance to TTX has been widely studied, but it remains unclear in the evolution history of voltage-gated sodium channel resistance to TTX in pufferfish with different TTX concentrations. In this study, six scn4aa coding sequences of pufferfish were firstly cloned and sequenced, then used to investigate the adaptive evolution of scn4aa associated with TTX concentration and reconstruct ancestral sequences with seven scn4aa of other fishes. The result of CODEML (codon substitution model) program from the PAML (phylogenetic analysis by maximum likelihood) package shows only in the genus of Takifugu, which contains TTX highly in the liver, under positive selection. The result also indicates that three of four positively selected sites are located in the intracellular regions, which may compensate for normal function. The ancestral sequence reconstruction may suggest that the replacements providing weak toxin resistance might have appeared first in scn4aa, then the genus Takifugu evolved stronger resistance to TTX later. These results contribute to the explanation of the evolutional history of voltage-gated sodium channel resistance to TTX in pufferfish. [ABSTRACT FROM AUTHOR]

The orange-spotted grouper (Epinephelus coioides) is one of the most popular fish in aquaculture due to its high economic value. However, the random occurrence of slow-growing population has led to profit loss. Therefore, transcriptomic analysis was performed to identify the molecular mechanisms involved in driving slow and fast growth, towards addressing this issue. Results show that low expression of developmental genes such as bone morphogenetic protein 1 (BMP 1) and somatostatin (SST), as well as GH/IGF axis-related genes (IGF-1, IGF2, IGFBP1, IGFBP2) and its downstream signalling pathways are correlated with the metabolism and digestive-system-related pathways in slow-growing groupers. Enrichment analysis further revealed that cellular process and biological regulation, as well as several pathways including glycolysis/gluconeogenesis, linoleic acid metabolism, protein digestion and absorption, and cholesterol metabolism were differentially expressed in slow-growing groups. The findings implied that the genomic architecture of growth between the different families raised and the likely problem of inbreeding have led to significantly reduced growth. It is also suggested that better husbandry practices (optimal dietary requirement) is also vital in supporting the success of a genetic improvement programme. These findings recommend growth improvement of orange-spotted groupers via molecular monitoring and artificial selection, complemented by specific dietary feeding. [ABSTRACT FROM AUTHOR]

In the latest years, the concentration levels of certain metals and metalloids in the sediments of the Galician Rías have shown an increasing trend (e.g., As, Zn, Cu, Pb, Hg). These areas are also characterized by their richness in nutrients and their great aquaculture or mariculture activity, with the presence of more than 3500 mussel rafts in the Rías Baixas. The inner areas of the Galician Rías are subjected to activities that resuspend the sediment such as high levels of maritime traffic and dredging or cleaning operations. It is likely that a transfer of these elements to the water column happens during the resuspension of sediments caused by natural events or anthropogenic activities. In this study, selected samples of surface sediments of the Ría de Pontevedra (NW Spain) were subjected to a procedure of aerobic oxidation to determine the concentration of some elements (Fe, Mn, Cu, Cr, Pb, Hg, and Zn) released from the sediment to the aqueous phase. The experiment was carried out within 5 days. Measurements of pH and total concentration were taken both in water and sediment samples. Furthermore, speciation of trace elements was carried out in the sediment samples. Trace element concentrations were lower in the sediments during aerobic oxidation, being released to the aqueous phase. From an environmental point of view, Cu was the only trace element released in quantities that may be toxic for the organisms in the area. This problem of sediment oxidation related to dredging activities or natural storm conditions should be considered in environmental impact studies and transferred to stakeholders. [ABSTRACT FROM AUTHOR]

Metal contamination is a crucial environmental issue because of its persistence and toxicity, which can have deleterious effects on aquatic ecosystems. Coastal sediments serve as reservoirs for metals. Aquaculture is an important human activity in coastal areas; however, the actual status of metal distribution in these areas has not been well characterized. We investigated the distribution and geochemical speciation of metals in the sediments of the Japanese aquaculture areas of Shidugawa and Furue Bays. Total metals were generally in the order Zn > Cu > Ni > Cd > Pb and occurred at high levels at the sites in the inner parts and near the fish cages in the sampling areas. Pearson's correlations and principal component analysis results suggested that the metals in these aquaculture areas might originate from several sources, such as fish feces, fish feeds, corrosion of antifouling material residues, and local anthropogenic activities, including fertilizers and manures. Furthermore, metals were mainly in silts and fine sediments, associated with residual speciation, followed by organic fractions, oxides, and high fractions of exchangeable Cd. These results provide important insights into the accumulation of metals in sediments for better managing marine aquaculture in Japan. [ABSTRACT FROM AUTHOR]

The understanding of the increasing population density of copepods in culture tanks contributes to establish their stable cultures at high productions for aquaculture industry, which are preferred live feeds for fish larvae. In the present study, the semibenthic copepod Pseudodiaptomus nihonkaiensis were used as target species. This genus is often found from brackish water and its tolerance to a wide range of salinity and water quality has attracted attention as a potential commercial live feed for aquaculture. Population growth and egg production in the semi-benthic copepod P. nihonkaiensis are investigated. Copepods were cultured in tanks without mesh, with mesh lining tank walls, and with 2, 4 or 8 mesh partitions in each tank to identify the effect of substratum surface area on copepod population density. Linear regression revealed peaks in nauplius, copepodite, adult and total densities, and the cumulative number of eggs for all sampling events to correlate positively with substratum surface area (p<0.01). Greater substratum area within a culture tank may improve egg production by increasing habitat for ovigerous females. The simple installation of inexpensive artificial substrata in existing copepod culture tanks might improve the feasibility of using copepods as a live food in commercial-scale aquaculture [ABSTRACT FROM AUTHOR]

With the burgeoning global demand for seafood, potential solutions like aquaculture are increasingly significant, provided they address issues like pollution and food security challenges in a sustainable manner. However, significant obstacles such as disease outbreaks and inaccurate biomass estimation underscore the need for optimized solutions. This paper proposes "Fish-Sense", a deep learning-based pipeline inspired by the human visual system's ability to recognize and classify objects, developed in conjunction with fish farms, aiming to enhance disease detection and biomass estimation in the aquaculture industry. Our automated framework is two-pronged: one module for biomass estimation using deep learning algorithms to segment fish, classify species, and estimate biomass; and another for disease symptom detection symptoms, employing deep learning algorithms to classify fish into healthy and unhealthy categories, and subsequently identifying symptoms and locations of bacterial infections if a fish is classified as unhealthy. To overcome data scarcity in this field, we have created four novel real-world datasets for fish segmentation, health classification, species classification, and fish part segmentation. Our biomass estimation algorithms demonstrated substantial accuracy across five species, and the health classification. These algorithms provide a foundation for the development of industrial software solutions to improve fish health monitoring in aquaculture farms. Our integrated pipeline facilitates the transition from research to real-world applications, potentially encouraging responsible aquaculture practices. Nevertheless, these advancements must be seen as part of a comprehensive strategy aimed at improving the aquaculture industry's sustainability and efficiency, in line with the United Nations' Sustainable Development Goals' evolving interpretations. The code, trained models, and the data for this project can be obtained from the following GitHub repository: https://github.com/Vision-At-SEECS/Fish-Sense. [ABSTRACT FROM AUTHOR]

People living in coastal areas have the advantage of accessing a high level of ecosystem services, but are also exposed to the dangers inherent in living by the sea in an area prone to natural disasters. To achieve sustainable utilization of the high ecosystem services of coastal areas, establishment of an effective marine policy based on regional characteristics of human–nature interactions is essential. We compared the structure of perceived satisfaction for five components of human well-being ('Security', 'Basic material for a good life', 'Good social relations', 'Health', and 'Freedom of choice and action') derived from coastal ecosystem services among three sites in Japan (Wakasa, Sanriku, and Shima) that share the same natural and social backgrounds: highly dependent on fisheries industry, located in the same climate regime (temperate zone), and have similar topographical features (ria coast). Structural equation modeling using the results from questionnaire surveys showed that the three sites shared a common basic structure of the interactions among the five components of human well-being. However, the intensity of interactions among components differed among the three sites. Questionnaire surveys on anxiety about natural disasters and future access to marine ecosystem services were simultaneously conducted at the three sites. The site-specific anxieties were responsible for the difference in the interactions among the five components of human well-being. We propose a method that quantitatively evaluates both positive (satisfaction) and negative (anxiety) aspects of respondents' subjective assessment as a useful tool for understanding the diversity of human–nature interactions caused by the region-specific natural and social backgrounds of coastal areas. [ABSTRACT FROM AUTHOR]