Physiological responses of tambaqui (Colossoma macropomum) fed diets supplemented with silage from fish and vegetables residues / Respostas fisiológicas de tambaqui (Colossoma macropomum) alimentado com dietas suplementadas com silagem de resíduos de pescado e vegetais

The demand for products to replace high-cost raw materials, such oil and fish meal, in the manufacture of feed for use in aquaculture, while also guaranteeing the nutritional quality of the diets, is increasing. Silage produced with fish and vegetables residues is a low-cost and efficient protein source. The objective of the present study was to evaluate the physiological and biochemical responses of tambaqui fingerlings fed four different levels of silage included in commercial feed with 28% crude protein, over two periods: 45 and 90 days. Each treatment was carried out over three replications, with 10 tambaqui in each 100 L experimental tank. At the end of each established period, blood samples were collected from five animals from each repetition to determine the hematological and biochemical variables. Body weight and total length, hepatosomatic and liposomal indices and hematocrit of specimens fed with diets supplemented with silage did not exhibit significant changes in both assessment period. After 45 days of feeding, the hemoglobin concentration increased when tambaqui were fed a diet including 20% silage. The red blood cell count, mean corpuscular volume and mean corpuscular hemoglobin did not change between treatments in either period. The total protein concentrations increased significantly in the plasma of tambaqui fed with diets with the inclusion of 5 and 10% of silage, evaluated after feeding for 45 days. It was found that the groups which had silage included in their diet did not exhibit significant alterations in the evaluated parameters, and the diet was therefore not consider harmful to the health of tambaqui. Therefore, the use of silage as a feed supplement during tambaqui farming is a sustainable alternative for producers, as it leads to a reduction of impacts of fish and vegetables waste disposal.

A procura por insumos que substituam produtos de alto custo, como óleo e farinha de peixe, na fabricação de rações para uso na aquicultura é crescente, sendo necessário garantir a qualidade nutricional das dietas. A silagem produzida a partir de resíduos de pescado e de vegetais apresenta-se como uma alternativa de baixo custo e eficiente fonte proteica. O objetivo do presente estudo foi avaliar as respostas fisiológicas e bioquímicas de alevinos de tambaqui alimentados com quatro níveis de inclusão de silagem em ração comercial com 28% de proteína bruta, em dois períodos: 45 e 90 dias. Cada tratamento foi realizado em três repetições, com 10 tambaquis em cada caixa experimental de 100 L. Ao término de cada período estabelecido, amostras sanguíneas foram coletadas de cinco animais de cada repetição para determinação das variáveis hematológicas e bioquímicas. Peso, comprimento total e índices hepatossomático e lipossomático de espécimes alimentados com silagem não mostraram alterações significativas em ambos os períodos de avaliação, bem como os valores de hematócrito. A concentração de hemoglobina de tambaqui após 45 dias de alimentação aumentou quando foi fornecida dieta com inclusão de 20% de silagem. A contagem de eritrócitos, volume corpuscular médio e hemoglobina corpuscular média não apresentaram alterações entre os tratamentos, em ambos os períodos. As proteínas totais aumentaram significativamente no plasma de tambaquis que receberam dietas com inclusão de 5 e 10% de silagem, avaliados após 45 dias de alimentação. Evidenciou-se que os grupos com inclusão de silagem na dieta não apresentaram alterações significativas nos parâmetros avaliados, assim não sendo prejudiciais à higidez do tambaqui. Portanto, o uso da silagem como suplemento alimentar durante o cultivo do tambaqui é uma alternativa sustentável para produtores, por promover a redução do descarte de resíduos de pescado e da agricultura.

Evaluation of different Starch Binders on physical quality of fish feed pellets / Avaliação de diferentes aglutinantes de amido na qualidade física de rações para peixes

Binders are the products that are used to bind, glue or hold the various feed ingredients together in order to maintain pellet integrity. For aqua-culturists, feed manufacturing is an expensive exercise due to the high cost of ingredients along with traditional artificial binders. The use of grain starches as aqua feed binders have advantages which include availability of that binder, nutritional contribution, and minimization of feed cost. A research trial was conducted to test physical properties such as palatability, water stability, dustiness, friability, settling velocity and floatation time of locally available starch i.e. wheat gluten, pea starch and guar gum and to assist their incorporation in on-farm aqua feed. Results revealed that among these three starch, the starch from pea source was proved superior over other two (wheat gluten and guar gum) as all physical quality parameters (dustiness, water stability and friability) revealed better performance of pea starch except pelletability in which guar gum performed best. Although not a single diet proved best in case of flotation time (Tf) and settling velocity (Vset) at varying lengths (6mm, 9mm and 12 mm). This finding indicates the significance of suitable binders for optimal water pollution and sustainable aquaculture. The use of these binders i.e. wheat gluten, pea starch and guar gum in fish feed pellets may also reduce dependence on synthetic binders and minimizes cost.

Aglutinantes são produtos usados para unir, colar ou manter juntos os vários ingredientes da ração, a fim de conservar a integridade do pellet. Para os aquicultores, a fabricação de ração é uma atividade difícil e cara por causa do alto preço dos aglutinantes artificiais tradicionais. O uso de amidos de grãos como aglutinantes de rações aquáticas tem vantagens que incluem acessibilidade, disponibilidade, contribuição nutricional e minimização do custo da ração. Um ensaio de pesquisa foi conduzido para testar propriedades físicas, como palatabilidade, estabilidade em água, pulverulência, friabilidade, velocidade de sedimentação e tempo de flutuação de amido disponível localmente, ou seja, glúten de trigo, amido de ervilha e goma de guar, e para auxiliar sua incorporação em rações aquáticas. Os resultados revelaram que, entre esses três amidos, o amido de ervilha se mostrou superior aos outros dois (glúten de trigo e goma de guar), pois todos os parâmetros de qualidade física (pulverulência, estabilidade da água e friabilidade) obtiveram melhor desempenho, exceto peletabilidade, em que a goma de guar se destacou. Nenhuma dieta se mostrou melhor no caso de tempo de flotação (Tf) e velocidade de sedimentação em comprimentos variados (6 mm, 9 mm e 12 mm). Essa descoberta indica a importância de aglutinantes adequados para a poluição ótima da água e a aquicultura sustentável. O uso desses aglutinantes, ou seja, glúten de trigo, amido de ervilha e goma de guar, em pellets de ração para peixes também pode reduzir a dependência de aglutinantes sintéticos e minimizar o custo.

Sequencing and multiple antimicrobial resistance of Pseudomonas fluorescens isolated from Nile tilapia fish in Egypt / Sequenciamento e resistência antimicrobiana múltipla de Pseudomonas fluorescens isoladas de tilápia-do-nilo no Egito

Pseudomonas fluorescens is one of the main causes of septicemic diseases among freshwater fish, causing severe economic losses and decreasing farm efficiency. Thus, this research was aimed to investigate the occurrence of P. fluorescens in Nile Tilapia (O. niloticus) fish in Egypt, gene sequencing of 16SrDNA gene, and antimicrobial susceptibility. P. fluorescens strains were detected in 32% (128/400) of apparently healthy (9%; 36/400) and diseased (23%; 92/400) Nile tilapia fish. The highest prevalence was observed in gills of fish, 31.3% followed by intestine 26.9%, liver 24.2%, and kidneys 17.6%. The PCR results for the 16SrDNA gene of P. fluorescens showed 16SrDNA gene in 30% of examined isolates. Moreover, Homogeny and a strong relationship between strains of P. fluorescens was confirmed using 16SrDNA sequences. Beside the responsibility of 16SrDNA gene on the virulence of P. fluorescens. The results of antimicrobial susceptibility tests revealed that all strains were resistant to piperacillin (100%), followed by ceftazidime (29.7%), and cefepime (25.8%). The strains of P. fluorescence were highly sensitive to cefotaxime (74.2%), followed by ceftriaxone and levofloxacin (70.3% each). Interestingly, 29.7% of strains of P. fluorescens were multiple antimicrobial-resistant (MAR).

Pseudomonas fluorescens é uma das principais causas de doenças septicêmicas em peixes de água doce, causando graves perdas econômicas e diminuindo a eficiência da fazenda. Assim, esta pesquisa teve como objetivo investigar a ocorrência de P. fluorescens em peixes de tilápia-do-nilo (O. niloticus) no Egito, sequenciamento do gene 16S rDNA e suscetibilidade antimicrobiana. Cepas de P. fluorescens foram detectadas em 32% (128/400) de peixes tilápia-do-nilo aparentemente saudáveis ​​(9%; 36/400) e doentes (23%; 92/400). A maior prevalência foi observada nas brânquias dos peixes, 31,3%, seguida pelo intestino 26,9%, fígado 24,2% e rins 17,6%. Os resultados da PCR para o gene 16SrDNA de P. fluorescens mostraram o gene 16SrDNA em 30% dos isolados examinados. Além disso, a homogeneidade e uma forte relação entre cepas de P. fluorescens foi confirmada usando sequências de 16SrDNA. Além da responsabilidade do gene 16SrDNA na virulência de P. fluorescens. Os resultados dos testes de suscetibilidade antimicrobiana revelaram que todas as cepas foram resistentes à piperacilina (100%), seguida pela ceftazidima (29,7%) e cefepima (25,8%). As cepas de P. fluorescens foram altamente sensíveis à cefotaxima (74,2%), seguida pela ceftriaxona e levofloxacina (70,3% cada). Curiosamente, 29,7% das cepas de P. fluorescens eram multirresistentes a antimicrobianos (MAR).

Growth performance and survivability of the Asian seabass Lates calcarifer (Bloch, 1790) reared under hyper-saline, hypo-saline and freshwater environments in a closed aquaculture system / Desempenho de crescimento e sobrevivência do robalo asiático Lates calcarifer (Bloch, 1790) criado em ambientes hipersalinos, hipossalinos e de água doce em um sistema de aquicultura fechado

Salinity is one of the most critical environmental parameters regarding fish physiology, modifying food intake and growth performance in many fish species. The present study has investigated the effects of different salinity levels on growth performance, feeding and survival of Asian seabass Lates calcarifer juveniles. Asian seabass juveniles were reared at 0 (T1), 5 (T2), 22 (T3), 36 (T4), and 42 (T5) ppt salinity. Approximately eight hundred thirty fish individuals with an average weight of 1.24±0.52 g were randomly distributed (166 fish/Tank) in 5 concrete tanks (each tank 30×6×4 ft, volume 19,122 L) for forty days. Juveniles were initially fed 42% crude protein-containing diets at a rate of 6% of their body weight per day. The results showed that salinity level had a significant effect on the weight gain (WG), average daily weight gain (ADWG), specific growth rate (SGR), feed conversion ratio (FCR), survival rate (SR), total biomass and health indices (p<0.05). The highest WG (39.11±1.49 g), ADWG (1.00±0.12 g), SGR (8.74±0.03% d-1) and lowest FCR (0.96±0.20) were observed with T3 treatment, which was significantly higher compared to other treatment groups (p<0.05). Among the health indices, the highest hepatosomatic index and viscerosomatic index were found with T3 treatment, significantly higher than the other groups (p<0.05). No significant differences were found among the treatments in terms of survival rate (p>0.05), but the maximum survival rate (98.89±0.0%) was observed in the T3 and T2 treatments. The maximum level of crude proteins (19.99±1.4%) was found in the whole-body biochemical composition of Asian seabass juveniles in the T3 treatment group. The second-order polynomial regression showed that 20 ppt salinity is optimum for the best growth of Asian seabass. Thus, the present study recommends 20 to 36 ppt salinity for the commercial farming of Asian seabass under a closed aquaculture system.

A salinidade é um dos parâmetros ambientais mais críticos em relação à fisiologia dos peixes, modificando a ingestão de alimentos e o desempenho de crescimento em muitas espécies. O presente estudo investigou os efeitos de diferentes níveis de salinidade no desempenho de crescimento, alimentação e sobrevivência de jovens espécies de robalos asiáticos Lates calcarifer, as quais foram criadas sob salinidade 0 (T1), 5 (T2), 22 (T3), 36 (T4) e 42 (T5) ppt. Aproximadamente 830 indivíduos de peixes com peso médio de 1,24 ± 0,52 g foram distribuídos aleatoriamente (166 peixes / tanque) em cinco tanques de concreto (cada tanque tinha 30 × 6 × 4 pés (9,1 x 1,8 x 1,2 metros), com volume de 19,12 litros) por 40 dias. Os peixes foram inicialmente alimentados com uma dieta contendo 42% de proteína bruta a uma taxa de 6% do seu peso corporal por dia. Os resultados mostraram que o nível de salinidade teve um efeito significativo no ganho de peso (GP), ganho de peso médio diário (GPMD), taxa de crescimento específico (TCE), taxa de conversão alimentar (TCA), taxa de sobrevivência (TS), biomassa total e índices de saúde (p < 0,05). O maior GP (39,11 ± 1,49 g), GPMD (1,00 ± 0,12 g), TCE (8,74 ± 0,03% d-1) e o menor TCA (0,96 ± 0,20) foram observados com o tratamento T3, que foi significativamente superior em comparação com os outros tratamentos (p < 0,05). Entre os índices de saúde, os maiores índices hepatossomáticos e viscerossomáticos foram encontrados no tratamento T3, significativamente superior do que os demais grupos (p < 0,05). Não foram encontradas diferenças significativas entre os tratamentos quanto à TS (p > 0,05), mas a TS máxima (98,89 ± 0,0%) foi observada nos tratamentos T3 e T2. O nível máximo de proteína bruta (19,99 ± 1,4%) foi encontrado na composição bioquímica dos corpos dos jovens robalos asiáticos no grupo T3. A regressão polinomial de segunda ordem mostrou que a salinidade de 20 ppt é ótima para o melhor crescimento do robalo asiático. Assim, o presente estudo recomenda salinidade de 20 a 36 ppt para o cultivo comercial de robalo asiático em sistema de aquicultura fechado.

Core species and interactions prominent in fish-associated microbiome dynamics.

BACKGROUND: In aquatic ecosystems, the health and performance of fish depend greatly on the dynamics of microbial community structure in the background environment. Nonetheless, finding microbes with profound impacts on fish's performance out of thousands of candidate species remains a major challenge. METHODS: We examined whether time-series analyses of microbial population dynamics could illuminate core components and structure of fish-associated microbiomes in the background (environmental) water. By targeting eel-aquaculture-tank microbiomes as model systems, we reconstructed the population dynamics of the 9605 bacterial and 303 archaeal species/strains across 128 days. RESULTS: Due to the remarkable increase/decrease of constituent microbial population densities, the taxonomic compositions of the microbiome changed drastically through time. We then found that some specific microbial taxa showed a positive relationship with eels' activity levels even after excluding confounding effects of environmental parameters (pH and dissolved oxygen level) on population dynamics. In particular, a vitamin-B12-producing bacteria, Cetobacterium somerae, consistently showed strong positive associations with eels' activity levels across the replicate time series of the five aquaculture tanks analyzed. Network theoretical and metabolic modeling analyses further suggested that the highlighted bacterium and some other closely-associated bacteria formed "core microbiomes" with potentially positive impacts on eels. CONCLUSIONS: Overall, these results suggest that the integration of microbiology, ecological theory, and network science allows us to explore core species and interactions embedded within complex dynamics of fish-associated microbiomes.  Video Abstract.

Coastal aquaculture regulates phosphorus cycling in estuarine wetlands: Mobilization, kinetic resupply, and source-sink process.

Estuarine mangrove wetlands have gradually declined owing to the growing construction of aquaculture ponds. How the speciation, transition, and migration of phosphorus (P) adaptively change in the sediments of this pond-wetland ecosystem remains unclear. In this study, we used high-resolution devices to explore the contrasting P behaviors associated with the redox cycles of Fe-Mn-S-As in estuarine and pond sediments. The results showed that the construction of aquaculture ponds increased the content or percentage of the silt, organic carbon, and P fractions in sediments. Dissolved organic P (DOP) concentrations in pore water were fluctuant with depths, accounting for only 18±15% and 20±11% of total dissolved P (TDP) in estuarine and pond sediment, respectively. Furthermore, DOP was less strongly correlated with other P species, including Fe, Mn, and sulfide. The coupling of dissolved reactive P (DRP) and TDP with Fe and sulfide confirmed that P mobility is regulated by Fe redox cycling in estuarine sediments, whereas Fe(III) reduction and sulfate reduction co-regulate P remobilization in pond sediments. The apparent diffusion flux revealed all sediments acting as sources for TDP (0.04-0.1 mg m-2 d-1) to the overlying water, while mangrove sediments were sources of DOP, and pond sediments were major sources of DRP. The DIFS model overestimated the P kinetic resupply ability, which was evaluated using DRP rather than TDP. This study improves our understanding of P cycling and budget in aquaculture pond-mangrove ecosystems and has important implications for understanding water eutrophication more effectively.

Global, regional, and cryptic population structure in a high gene-flow transatlantic fish.

Lumpfish (Cyclopterus lumpus) is a transatlantic marine fish displaying large population sizes and a high potential for dispersal and gene-flow. These features are expected to result in weak population structure. Here, we investigated population genetic structure of lumpfish throughout its natural distribution in the North Atlantic using two approaches: I) 4,393 genome wide SNPs and 95 individuals from 10 locations, and II) 139 discriminatory SNPs and 1,669 individuals from 40 locations. Both approaches identified extensive population genetic structuring with a major split between the East and West Atlantic and a distinct Baltic Sea population, as well as further differentiation of lumpfish from the English Channel, Iceland, and Greenland. The discriminatory loci displayed ~2-5 times higher divergence than the genome wide approach, revealing further evidence of local population substructures. Lumpfish from Isfjorden in Svalbard were highly distinct but resembled most fish from Greenland. The Kattegat area in the Baltic transition zone, formed a previously undescribed distinct genetic group. Also, further subdivision was detected within North America, Iceland, West Greenland, Barents Sea, and Norway. Although lumpfish have considerable potential for dispersal and gene-flow, the observed high levels of population structuring throughout the Atlantic suggests that this species may have a natal homing behavior and local populations with adaptive differences. This fine-scale population structure calls for consideration when defining management units for exploitation of lumpfish stocks and in decisions related to sourcing and moving lumpfish for cleaner fish use in salmonid aquaculture.

Optimizing facility location, sizing, and growth time for a cultivated resource: A case study in coral aquaculture.

Production of cultivated resources require additional planning that takes growth time into account. We formulate a mathematical programming model to determine the optimal location and sizing of growth facilities, impacted by resource survival rate as a function of its growth time. Our method informs strategic decisions regarding the number, location, and sizing of facilities, as well as operational decisions of optimal growth time for a cultivated resource in a facility to minimize total costs. We solve this facility location and sizing problem in the context of coral aquaculture for large-scale reef restoration using a two-stage algorithm and a linear mixed-integer solver. We assess growth time in a facility in terms of its impact on survival (post-deployment) considering growth quantity requirements and growth facility production constraints. We explore the sensitivity of optimal facility number, location, and sizing to changes in the geographic distribution of demand and cost parameters computationally. Results show that the relationship between growth time and survival is critical to optimizing operational decisions for grown resources. These results inform the value of data certainty to optimize the logistics of coral aquaculture production.

Impact assessment of human activities on resources of juvenile horseshoe crabs in Hainan coastal areas, China.

The booming coastal zone economy poses increasing anthropogenic threats to marine life and habitats. Using the endangered living fossil horseshoe crab (HSC) as an example, we quantified the intensity of various anthropogenic pressures along the coast of Hainan Island, China, and for the first time assessed their impact on the distribution of juvenile HSCs through a field survey, remote sensing, spatial geographic modeling, and machine learning methods. The results indicate that the Danzhou Bay needs to be protected as a priority based on species and anthropogenic pressure information. Aquaculture and port activities dramatically impact the density of HSCs and therefore be managed priority. Finally, a threshold effect between total, coastal residential, and beach pressure and the density of juvenile HSCs were detected, which indicates the need for a balance between development and conservation as well as the designation of suitable sites for the construction of marine protected areas.

Adolescent girls in aquaculture ecozones at risk of nutrient deficiency in Bangladesh development and validation of an integrated metric.

BACKGROUND: This study developed and validated an integrated metric that enhances understanding of linkages between agro-ecological and socio-economic factors that are important for explaining nutritional wellbeing in relation to fish consumption; especially among adolescent girls who are at risk of nutritional deficiency in Bangladesh. Currently, there is no metric that takes account of environmental, cultural and economic contexts when considering fish consumption and dietary health from a policy perspective. METHODS: The study was designed as a bi-seasonal survey, repeated in the same population of adolescent girls recruited during the dry and wet seasons. Sampling was stratified by five settings (four aqua-agroecological zones and one processing plant community), with 60 girls recruited in each. Associations between candidate predictors (salinity, diet diversity, religion, socio-economic status and women's autonomy score) and dependent variables representing nutritional outcomes (anthropometry, omega-3 index and micronutrient levels) were explored in multivariable regressions. The fitted model with its predictors was validated, and a risk score derived from responses to a few short questions on religion, salinity zone, female autonomy, diet diversity and tilapia consumption. RESULTS: The omega-3 index showed the clearest distinction between seasons, by salinity and religion. Higher female autonomy, religion (being Hindu rather than Muslim), geographical location (living in a high or mid-saline area), and a higher dietary diversity were the strongest predictors of whole blood omega-3 index. The c-index for the prognostic model was 0.83 and 0.76 in the wet and dry season respectively, indicating good predictive accuracy. There appeared to be a clear trend in risk scores differentiating between those 'chronically at risk' and those 'never at risk'. CONCLUSIONS: Observational data on different aquaculture-ecozones defined by salinity enabled us to establish linkages between seasonal fish intake, religion, diet diversity, female autonomy and nutritional wellbeing. The purpose of the metric is to reveal these specific linkages in practice. This tool should improve targeting of timely, preventative and cost-effective nutritional interventions to adolescent girls most at-risk from low omega-3 levels in communities where seafood is produced.

Screening and characterization of sex-specific sequences through 2b-RAD sequencing in American shad (Alosa sapidissima).

American shad (Alosa sapidissima), introduced from the United States, has become one of the most expensive farmed fish in the aquatic product market of China. The shad reveals significant sexual dimorphism in growth and behaviors. For the study, five male-specific tags were identified in two-generation breeding populations of Alosa sapidissima and were verified by PCR amplification. Averages of 10,245,091 and 8,685,704 raw and enzyme reads were obtained by high-throughput sequencing of the 2b-RAD library, respectively. 301,022 unique tags were obtained from the sequences of twenty samples with sequencing depths of 0 to 500. Finally, 274,324 special tags and 29,327 SNPs were selected with a sequencing depth of 3 to 500. Eleven preliminary screening male-specific tags and three male heterogametic SNP loci were isolated. After verification by PCR amplification, five male-specific sequences of 27 bp located on chromosome 3 were screened out. Chromosome 3 could be assumed to be the sex chromosome of Alosa sapidissima. Sex-specific markers will provide invaluable and systematic animal germplasm resources to allow for the precise identification of neo-males for the all-female breeding of Alosa sapidissima in commercial aquaculture.

Abnormal Behavior Monitoring Method of Larimichthys crocea in Recirculating Aquaculture System Based on Computer Vision.

It is crucial to monitor the status of aquaculture objects in recirculating aquaculture systems (RASs). Due to their high density and a high degree of intensification, aquaculture objects in such systems need to be monitored for a long time period to prevent losses caused by various factors. Object detection algorithms are gradually being used in the aquaculture industry, but it is difficult to achieve good results for scenes with high density and complex environments. This paper proposes a monitoring method for Larimichthys crocea in a RAS, which includes the detection and tracking of abnormal behavior. The improved YOLOX-S is used to detect Larimichthys crocea with abnormal behavior in real time. Aiming to solve the problems of stacking, deformation, occlusion, and too-small objects in a fishpond, the object detection algorithm used is improved by modifying the CSP module, adding coordinate attention, and modifying the part of the structure of the neck. After improvement, the AP50 reaches 98.4% and AP50:95 is also 16.2% higher than the original algorithm. In terms of tracking, due to the similarity in the fish's appearance, Bytetrack is used to track the detected objects, avoiding the ID switching caused by re-identification using appearance features. In the actual RAS environment, both MOTA and IDF1 can reach more than 95% under the premise of fully meeting real-time tracking, and the ID of the tracked Larimichthys crocea with abnormal behavior can be maintained stably. Our work can identify and track the abnormal behavior of fish efficiently, and this will provide data support for subsequent automatic treatment, thus avoiding loss expansion and improving the production efficiency of RASs.

Solar-enhanced bio-electro-Fenton driven by sediment microbial fuel cell for ametryn degradation in simulated seawater.

In marine aquaculture areas, herbicides have been used to inhibit the wild growth of seaweed, which may seriously affect the ecological environment and food safety. Here the commonly applied ametryn was used as the representative pollutant, and solar enhanced bio-electro-Fenton driven in situ by sediment microbial fuel cell (SMFC) was proposed to degrade ametryn in simulated seawater. SMFC with γ-FeOOH-coated carbon felt cathode was operated under the simulated solar light (γ-FeOOH-SMFC), where two-electron oxygen reduction and activation of H2O2 occurred to promote the production of hydroxyl radicals at the cathode. Hydroxyl radicals, photo-generated holes, and anodic microorganism worked together to degrade ametryn with an initial concentration of 2 mg/L in the self-driven system. The removal efficiency of ametryn in γ-FeOOH-SMFC was 98.7 % during the operation period of 49 days, which was 6 times higher than that under natural degradation condition. When γ-FeOOH-SMFC was in the steady phase, oxidative species were continuously and efficiently generated. The maximum power density (Pmax) of γ-FeOOH-SMFC was 44.6 W/m3. According to the intermediate products of ametryn degradation in γ-FeOOH-SMFC, four possible pathways of ametryn degradation were proposed. This study provides an effective, cost-saving, and in situ treatment for refractory organics in seawater.

Environmental footprints of farmed chicken and salmon bridge the land and sea.

Food production, particularly of fed animals, is a leading cause of environmental degradation globally.1,2 Understanding where and how much environmental pressure different fed animal products exert is critical to designing effective food policies that promote sustainability.3 Here, we assess and compare the environmental footprint of farming industrial broiler chickens and farmed salmonids (salmon, marine trout, and Arctic char) to identify opportunities to reduce environmental pressures. We map cumulative environmental pressures (greenhouse gas emissions, nutrient pollution, freshwater use, and spatial disturbance), with particular focus on dynamics across the land and sea. We found that farming broiler chickens disturbs 9 times more area than farming salmon (∼924,000 vs. ∼103,500 km2) but yields 55 times greater production. The footprints of both sectors are extensive, but 95% of cumulative pressures are concentrated into <5% of total area. Surprisingly, the location of these pressures is similar (85.5% spatial overlap between chicken and salmon pressures), primarily due to shared feed ingredients. Environmental pressures from feed ingredients account for >78% and >69% of cumulative pressures of broiler chicken and farmed salmon production, respectively, and could represent a key leverage point to reduce environmental footprints. The environmental efficiency (cumulative pressures per tonne of production) also differs geographically, with areas of high efficiency revealing further potential to promote sustainability. The propagation of environmental pressures across the land and sea underscores the importance of integrating food policies across realms and sectors to advance food system sustainability.

Acute and Sublethal Effects of Deltamethrin Discharges from the Aquaculture Industry on Northern Shrimp (Pandalus borealis Krøyer, 1838): Dispersal Modeling and Field Investigations.

Pharmaceutical deltamethrin (Alpha Max), used as delousing treatments in aquaculture, has raised concerns due to possible negative impacts on the marine environment. A novel approach combining different scientific disciplines has addressed this topic. Acute (mortality) and sublethal effects (i.e., fitness, neurological, immunological, and oxidative responses) of exposure of northern shrimp (Pandalus borealis) were studied in laboratory experiments. Passive water sampling combined with sediment analyses revealed environmental concentrations. Finally, dispersal modeling was performed to predict environmental concentrations. Ecotoxicological analyses showed mortality in shrimp after 1 h of exposure to 2 ng L-1 (1000-fold dilution of treatment dose), revealing a high sensitivity to deltamethrin. Sublethal effects included induction of acetylcholinesterase and acyl CoA oxidase activities and oxidative impairment, which may be linked to neurotoxic responses. Field concentrations of 10-200 ng L-1 in water (100 m from the pens) and

Bioinformatics approaches and big data analytics opportunities in improving fisheries and aquaculture.

Aquaculture has witnessed an excellent growth rate during the last two decades and offers huge potential to provide nutritional as well as livelihood security. Genomic research has contributed significantly toward the development of beneficial technologies for aquaculture. The existing high throughput technologies like next-generation technologies generate oceanic data which requires extensive analysis using appropriate tools. Bioinformatics is a rapidly evolving science that involves integrating gene based information and computational technology to produce new knowledge for the benefit of aquaculture. Bioinformatics provides new opportunities as well as challenges for information and data processing in new generation aquaculture. Rapid technical advancements have opened up a world of possibilities for using current genomics to improve aquaculture performance. Understanding the genes that govern economically relevant characteristics, necessitates a significant amount of additional research. The various dimensions of data sources includes next-generation DNA sequencing, protein sequencing, RNA sequencing gene expression profiles, metabolic pathways, molecular markers, and so on. Appropriate bioinformatics tools are developed to mine the biologically relevant and commercially useful results. The purpose of this scoping review is to present various arms of diverse bioinformatics tools with special emphasis on practical translation to the aquaculture industry.

Occurrence and distribution characteristics of aged microplastics in the surface water, sediment, and crabs of the aquaculture pond in the Yangtze River Delta of China.

The artificial breeding of freshwater crabs in China has become the main source, accounting for 45.69 % of the total output in 2020. However, microplastics widely exist in ponds due to the addition of meals, and the aging and breakage of plastic tools, and people know little about the occurrence of microplastics in the environment and the tissues of crabs during the cultivation of crabs in ponds. In this study, the abundance and characteristics of microplastics in ponds and crabs were studied finely, and the types of microplastics produced by meals and tools and the aging degree of microplastics in different media were studied in a typical aquaculture experimental base in the Yangtze Estuary of China. After we digested all the samples, there were microplastics in the water, sediment, and inedible part of crabs and crab meals, mainly in fiber shape, with a particle size of 100~300µm, and they have a certain degree of aging. The abundance of microplastics in surface water ranges from 4.4 to 10.8 items/L, and that in sediment ranges from 28.6 to 54.3 items/100 g·dry weight sediments. The average abundance of microplastics in crabs was 23.9 ± 15.9 items/individual. The content of microplastics in crabs' intestinal tissue was the highest, followed by gills and hepatopancreas. At the same time, the microplastics found in crabs were positively correlated with crab body weight and negatively correlated with hepatopancreas index. The results show that in the process of artificial breeding pond feeding, microplastics will be released from the process of meals dissolving in water, and fall off due to wear and tear during the use of tools. Microplastics found in the water, sediments and the tissues of crabs were all aged. Humans have a risk of ingesting microplastics when they eat the tissues of nonedible parts of crabs.

Colombian biodiversity is governed by a rich and diverse policy mix.

We lack an understanding of how diverse policymakers interact to govern biodiversity. Taking Colombia as a focal case, we examined six decades of biodiversity governance (1959-2018). Here we analysed the composition of the policy mix, and how it has evolved over time, how policies differ among lead actors and ecosystems, and whether the policy mix addresses the primary threats to biodiversity. We identified 186 biodiversity-related policies that govern multiple ecosystems, use different instruments and address the main threats to biodiversity (that is, agriculture and aquaculture, and biological resource use). We found policy gaps in the governance of invasive species and wildlife trade. Biodiversity policy integration into some sectoral policies, such as climate change, poverty and pollution, has become more common in the past decade. Our results point to an increased need for effective coordination across sectors and actors, as new ones influence and implement the policy mix.

Vibrio vulnificus, an Underestimated Zoonotic Pathogen.

V. vulnificus, continues being an underestimated yet lethal zoonotic pathogen. In this chapter, we provide a comprehensive review of numerous aspects of the biology, epidemiology, and virulence mechanisms of this poorly understood pathogen. We will emphasize the widespread role of horizontal gene transfer in V. vulnificus specifically virulence plasmids and draw parallels from aquaculture farms to human health. By placing current findings in the context of climate change, we will also contend that fish farms act as evolutionary drivers that accelerate species evolution and the emergence of new virulent groups. Overall, we suggest that on-farm control measures should be adopted both to protect animals from Vibriosis, and also as a public health measure to prevent the emergence of new zoonotic groups.