A seafood risk tool for assessing and mitigating chemical and pathogen hazards in the aquaculture supply chain

Microbial diversity and community structure of microalgae (Nannochloropsis oculata) and rotifer (Brachionus plicatilis) in aquaculture by 16S rRNA amplicon-based sequencing

Live cultures, including Nannochloropsis oculata and Brachionus plicatilis, are essential in aquaculture due to its economic and nutritional value for commercial fish species. Pathogens and probiotics can be introduced to aquaculture systems by live feed, with variations in abundance influenced by environmental physicochemical parameters. To investigate this, amplicon sequencing of the V3-V4 region of the 16S rRNA was conducted using Illumina MiSeq to elucidate bacterial abundances and their variations in response to changes in physicochemical parameters in live feed cultures. Results revealed that pathogens like, Tenacibaculum, predominantly found in rotifer cultures, was inhibited under dissolved oxygen levels of 6.87-8.19 mg/L and pH levels of 8.63-9.23. Winogradskyella, mainly present on day 1 of the microalgae culture, thrived under these same conditions. Potential probiotics were also analyzed. Phaeodactylibacter, primarily found on day 1 of microalgae cultures, was favored by dissolved oxygen levels of 7.11-7.68 mg/L and pH levels of 8.63-9.23 but was inhibited by nitrite levels of 0.46-0.5 mg/L. Overall, dissolved oxygen was the key parameter modulating microbial diversity. This study shows that optimizing environmental parameters can enhance culture health by promoting probiotics and reducing harmful bacteria.

Consumption Patterns and Willingness to Pay for Sustainable Aquatic Food in China

China, as the world's largest producer, trader, and consumer of aquatic foods, lacks comprehensive research on consumption patterns and willingness to pay for sustainable aquatic food. This study addressed this gap through an online survey of 3403 participants across Chinese provinces. A majority of consumers (34.7% of the participants) consume aquatic food twice or more per week, mainly from traditional markets (26%). Most prefer fresh or live products (76%), with 42% seeing no difference between farmed and wild options. Consumption is higher among older, affluent, urban, and coastal residents. Crustaceans, especially shrimp, are frequently consumed species, with growing interest in luxury species like salmon and abalone. Taste and quality emerge as the primary factors motivating consumer choices in aquatic food purchases. Food safety is the primary concern, followed by environmental impact. Notably, 92.4% of participants would pay extra for certified products. Factors influencing a higher willingness to pay include higher income, inland residence, price sensitivity, origin consciousness, and concerns about food safety and the environment. The findings highlight that China's aquatic food industry and consumption can become more sustainable by aligning with consumer preferences for high-quality and diverse aquatic food through both production and import, while also addressing concerns related to food safety and environmental impact. This research provides valuable insights into China's rapidly transforming aquatic food market landscape, offering implications for industry innovation and the promotion of sustainable consumption patterns.

One Health: Circadian Medicine Benefits Both Non-human Animals and Humans Alike

Circadian biology's impact on human physical health and its role in disease development and progression is widely recognized. The forefront of circadian rhythm research now focuses on translational applications to clinical medicine, aiming to enhance disease diagnosis, prognosis, and treatment responses. However, the field of circadian medicine has predominantly concentrated on human healthcare, neglecting its potential for transformative applications in veterinary medicine, thereby overlooking opportunities to improve non-human animal health and welfare. This review consists of three main sections. The first section focuses on the translational potential of circadian medicine into current industry practices of agricultural animals, with a particular emphasis on horses, broiler chickens, and laying hens. The second section delves into the potential applications of circadian medicine in small animal veterinary care, primarily focusing on our companion animals, namely dogs and cats. The final section explores emerging frontiers in circadian medicine, encompassing aquaculture, veterinary hospital care, and non-human animal welfare and concludes with the integration of One Health principles. In summary, circadian medicine represents a highly promising field of medicine that holds the potential to significantly enhance the clinical care and overall health of all animals, extending its impact beyond human healthcare.

Bacteriocins: potentials and prospects in health and agrifood systems

Bacteriocins are highly diverse, abundant, and heterogeneous antimicrobial peptides that are ribosomally synthesized by bacteria and archaea. Since their discovery about a century ago, there has been a growing interest in bacteriocin research and applications. This is mainly due to their high antimicrobial properties, narrow or broad spectrum of activity, specificity, low cytotoxicity, and stability. Though initially used to improve food quality and safety, bacteriocins are now globally exploited for innovative applications in human, animal, and food systems as sustainable alternatives to antibiotics. Bacteriocins have the potential to beneficially modulate microbiota, providing viable microbiome-based solutions for the treatment, management, and non-invasive bio-diagnosis of infectious and non-infectious diseases. The use of bacteriocins holds great promise in the modulation of food microbiomes, antimicrobial food packaging, bio-sanitizers and antibiofilm, pre/post-harvest biocontrol, functional food, growth promotion, and sustainable aquaculture. This can undoubtedly improve food security, safety, and quality globally. This review highlights the current trends in bacteriocin research, especially the increasing research outputs and funding, which we believe may proportionate the soaring global interest in bacteriocins. The use of cutting-edge technologies, such as bioengineering, can further enhance the exploitation of bacteriocins for innovative applications in human, animal, and food systems.

Comparative effects of different bacterial lipopolysaccharides on modulation of immune levels to improve survival of the black tiger shrimp

To prevent loss from disease, immunostimulants have been used as dietary supplements to improve immunity and survival of shrimps. Among the various types of immunostimulants, there is increasing evidence that a diet enriched with bacterial lipopolysaccharide can reduce the mortality rate of shrimp under exposure to pathogens. Here, the immunostimulatory effects of bacterial lipopolysaccharide (LPS) from various bacterial sources were explored. Bacterial LPS was extracted from a shrimp pathogen, Vibrio harveyi and its effects were compared with the commercially available LPS from the non-shrimp pathogen, Escherichia coli. Our results revealed that the LPS from V. harveyi was different in molecular size but contained similar functional groups to that from E. coli. To understand their molecular mechanisms, bacterial LPS from the two sources were applied as a supplementary diet and fed to juvenile shrimp for 4-week feeding period before tissue samples were collected for transcriptomic analysis by next generation sequencing. Gene expression profiling revealed that major immune-related genes such as pattern recognition proteins (PRPs), proteinases and proteinase inhibitors, prophenoloxidase systems (proPO system), antimicrobial peptides (AMPs), signaling transduction pathways, heat shock proteins (HSPs), oxidative stress responses, and other immune-related molecules such as mucins and peritrophins were modulated in the groups of shrimp fed with bacterial LPS from both sources, but at different levels. The results suggest that bacterial LPS could modulate shrimp immune system, and different LPS sources led to different activation of immune pathways. Additionally, metabolic-related genes were affected by LPS, suggesting that energy was required for immune stimulation. In the V. harveyi pathogen challenge trial, all shrimp groups fed with diets containing LPS from both bacterial sources showed better survival than the control group without LPS. When comparing groups fed with LPS supplemented diets, the higher concentration of LPS (8 μg/body weight) from E. coli resulted in a better survival rate than a lower concentration (4 μg/body weight). Conversely, shrimp fed with a diet containing LPS from V. harveyi showed a lower survival rate when a higher dose of LPS (8 μg/body weight) was administered than the group fed with a lower concentration of LPS (4 μg/body weight). This could be due to overstimulation of shrimp immune responses, especially by LPS derived from shrimp pathogens, resulting in a reverse effect. These results confirm that immunity in shrimp upon administration of bacterial LPS depends on the origin and dose of the LPS administered.

Marine Biotoxins in Whole and Processed Scallops from the Argentine Sea

Harmful algal blooms are an increasing worldwide threat to the seafood industry and human health as a consequence of the natural production of biotoxins that can accumulate in shellfish. In the Argentine Sea, this has been identified as an issue for the offshore fisheries of Patagonian scallops (Zygochlamys patagonica), leading to potentially harmful effects on consumers. Here we assess spatial and temporal patterns in marine biotoxin concentrations in Patagonian scallops harvested in Argentinian waters between 2012-2017, based on analyses for paralytic shellfish toxins, lipophilic toxins, and amnesic shellfish toxins. There was no evidence for concentrations of lipophilic or amnesic toxins above regulatory acceptance thresholds, with trace concentrations of pectenotoxin 2, azaspiracid 2 and okadaic acid group toxins confirmed. Conversely, paralytic shellfish toxins were quantified in some scallops. Gonyautoxins 1 and 2 dominated the unusual toxin profiles (91%) in terms of saxitoxin equivalents with maximum concentrations reaching 3985 µg STX eq/kg and with changes in profiles linked in part to seasonal changes. Total toxin concentrations were compared between samples of the adductor muscle and whole tissue, with results showing the absence of toxins in the adductor muscle confirming toxin accumulation in the digestive tracts of the scallops and the absence of a human health threat following the processing of scallop adductor meat. These findings highlight that paralytic shellfish toxins with an unusual toxin profile can occur in relatively high concentrations in whole Patagonian scallops in specific regions and during particular time periods, also showing that the processing of scallops on board factory ships to obtain frozen adductor muscle is an effective management process that minimizes the risk of poisonings from final products destined for human consumption.

Towards Sustainable Aquaculture: A Brief Look into Management Issues

Aquaculture’s role has expanded over the past two decades, with the industry contributing to nearly 50% of the overall fish production. Aquaculture production in Asia and Africa contributes a significant share of total global aquaculture output growth. Aquaculture supports livelihoods and income improvement in a number of states, despite the fact that economic situations have indeed been unfavourable and environmental concerns remain undeniable. To meet the growing demand for fish, aquaculture must expand. However, this expansion will not be sustainable unless management and planning are significantly improved. Local, national, and international management are needed to address the social, economic, and environmental problems. These provide the foundation to proper aquaculture management strategies. In considering the involved ecology, water quality, and genetics, aquaculture can have a detrimental impact on the environmental sustainability. This paper highlights the review on site selection with capacity evaluation, analysis of threats and risks, as well as certification and standards, which are all important considerations in achieving a sustainable aquaculture industry.