Pages: 94

No chapter abstract available.

Pages: 23

Disease diagnostics in aquaculture have evolved substantially in association with the developments in aquaculture and the discipline of aquatic veterinary medicine. In the past, fish disease diagnosis was primarily based on visual observations such as changes in behavior, physical appearance, and mortality rate. Typically, these methods are not specific enough, due to the lack of specificity, delayed and inaccurate diagnosis, leading to severe economic and ecological impacts. In the mid-20th century, significant progress was made in microbiology, histopathology, and molecular biology, leading to more precise identification of pathogens. Recently, the adoption of molecular diagnostic tools such as polymerase chain reaction (PCR) and next-generation sequencing (NGS) have considerably transformed the detection of fish pathogens, with high sensitivity and specificity. Additionally, advances in imaging technologies and the use of biomarkers allow for greater rapidity of assessment and monitoring of fish health. In the future, diagnostic tools are expected to integrate artificial intelligence (AI), and big data analytics, enabling real-time disease surveillance and more accurate predictions of disease outbreaks. The chapter reviews conventional disease diagnosis methods, such as clinical diagnosis, microscopic examination, microbial identification, and histopathologic studies in aquatic health management. This section also details immunological methods, omics-based molecular detection, different PCR diagnosis techniques, DNA microarray, etc. Overall, this preface contains an overview of the background, current status, and future perspectives of disease diagnostic tools, highlighting the continuous innovation that drives improvements in fish health management.

Pages: 17

Recent advancements in metagenomics have changed the perspective of fish pathogen infection, offering rapid and accurate detection of pathogens, which is a paramount necessity in an exponentially growing aquaculture industry. Traditional methods limit this ability as they depend on isolation and culture-based methods, which are time-consuming, hindering the timely response and the inability to identify non-culturable pathogens effectively. Integrating the metagenomic technique offers a promising solution, providing a transformative approach to pathogen detection, allowing researchers to identify known and novel pathogens directly from fish samples without the need for prior isolation or culture, enabling comprehensive pathogen detection, and monitoring in real time. The primary purpose of this chapter is to present how metagenomic technologies help explore the complexities of fish microbiomes, how they help identify the shifts in pathogenic profiles, and how they can be used in monitoring the progress of infections. Metagenomics supports comprehensive disease prevention and management frameworks by facilitating early diagnosis, monitoring pathogen resistance, and tracking epidemiological trends. This capability is particularly important in increasing antibiotic resistance, as it allows for the identification of resistant strains and the evaluation of treatment efficacy over time. These advancements not only streamline the research process but also facilitate the integration of metagenomic data into practical applications for disease management in aquaculture, enhancing the sustainability and productivity of aquaculture systems. The chapter anticipates several innovative developments in advanced metagenomic applications for fish health. In conclusion, the insights gained from this chapter will be instrumental in shaping future strategies for disease management in aquaculture, ultimately benefiting both human populations and aquatic ecosystems.

Pages: 17

Certain routines established during childhood persist into adulthood, becoming habitual practices that are often passed on to subsequent generations. One such routine is the act of washing hands before eating—a fundamental biosecurity measure performed almost instinctively. This simple yet effective practice, aimed at minimizing the risk of pathogen transfer from hands to food, exemplifies the manner in which biosecurity measures should be implemented—not as an additional or burdensome procedure, but as an integral and inherent component of daily life.

Pages: 16

Aquaculture biosecurity can enhance various production stages by reducing risk factors for disease transmission. Farm-level biosecurity has been recently practiced by farmers as an effective tool to prevent the spread of infectious diseases and to ensure improved health management on the farm. It is a new concept in aquaculture to protect aquatic animals from infectious diseases. Effective biosecurity planning on an aquaculture farm unit has several proven advantages in fish farming, including reduced risk of disease transmission across farms, the prevention of emerging diseases, and lowered economic losses attributed to disease. With that, selecting appropriate management practices and defining barriers can be challenging. The monitoring and management of aquafarm biosecurity has thus become a significant consideration that urges the development of proper biosecurity guidelines with a more targeted approach. The comparative study of biosecurity measures used at the local, national, and/or international levels for a particular aquaculture component can inform producers on how to integrate this guidance effectively and in a timely manner. Addressing the gaps and limitations in the existing farm-level biosecurity is essential to incorporate new elements into the checklist and ensure maximum protection under emerging disease threats. So, there is plenty of room for improving biosecurity in aquaculture and moving toward a sustainable and safe industry in the near future. It is also essential to keep in mind that the new regulatory framework and approaches are useful for a wide range of stakeholders; for example, the cost involved in the process of biosecurity management should be affordable for producers within low- to middle-income countries. So, to ensure that we are preparing to achieve the broader goal of biosecurity globally, focusing on a more integrated approach for the growing aquaculture industry.

Pages: 19

Global aquaculture is expanding as a result of the need to supply the world’s growing population with the increasing amount of protein they require from animal sources. The necessity to fulfill the rising animal-source protein has culminated the spread of aquaculture on a worldwide scale. In order to avoid bacterial illnesses on farms, especially in developing nations, there may be a corresponding rise in the use of medicated feeds, which are inexpensive and readily available. In-feed use of antimicrobials is generally considered improper for use in animal health due to their critical value to human medicine. It is therefore guaranteed that these antimicrobial agents will survive in the aquatic environment for a considerable amount of time when a wide variety of them, including those used in human medicine, are employed. Still, the persistence in the aquatic environment over time may cause antibiotic resistance to emerge. Sediment, fish-associated bacterial strains, and the surrounding microorganisms in the column water all develop antibiotic resistance. Through horizontal gene transfer, bacteria can spread genetic determinants by diffusing genes resistant to antibiotics and mobile resistance genes. Antibiotic resistance renders antibiotics useless for treating illnesses because it grows quickly, permeates aquatic microbial ecosystems, and eventually infects human diseases. Antimicrobial resistance (AMR) in aquaculture could be decreased with a more cautious and responsible use of veterinary medications. This can be achieved by improved health extension and diagnostic support services for farmers, increased regulatory frameworks, stricter government enforcement of current restrictions, and the prudent use of veterinary medications by fish farmers. However, antimicrobials should only be administered when alternative methods of disease prevention and control have been fully evaluated. This chapter sheds light on the complicated function that antibiotics play in aquaculture by offering a thorough analysis of the benefits and drawbacks of using them in fish farming.

Pages: 110

No chapter abstract available.

Pages: 21

Put simply, genomics refers to the study of the entire genome of an organism, whereas genetics refers to the study of a particular gene. More specifically, genomics is a broad field within molecular biology that focuses on the analysis of genomes, including their structure, function, mapping, and evolution, as well as the interactions between their genes as a whole and their interactions with the environment. As a result of mutation and genetic drift, the accumulation of differences in functional genomic sequences, which undergo evolutionary pressure, leads to intraspecies genetic variability and, in extreme cases, to speciation. Within a species, these interindividual differences are linked to distinct phenotypes, such as in the case of infectious diseases, the host’s susceptibility to pathogens on one side and the virulence of pathogens on the other side. This coevolutionary interplay holds significant biological interest, as it drives much of the genetic diversity underlying the ongoing interaction between hosts and pathogens, the understanding of which is highly valuable for multiple applications. However, past technical limitations largely restricted more in-depth exploration to pathogen genomes, which are typically smaller in size. Albeit invaluable and labor intensive, insights into the genomes of hosts were only provided for certain organisms and fragmentary. In both cases, such studies were driven by biomedical or economic considerations taking precedence.

Pages: 18

Genetic technologies, including genetic engineering and genome editing, offer promising solutions for combating infectious diseases in aquaculture. Historically, genetic engineering has significantly evolved, culminating in the emergence of precise genome-editing techniques such as clustered regularly interspaced short palindromic repeats and CRISPR associated protein 9 (CRISPR/Cas9). Currently, CRISPR/Cas9 represents a groundbreaking tool for site-specific genome modifications, facilitating targeted knock-in (transgenesis) and knock-out experiments in aquaculture-relevant species. Examples include enhancing disease resistance or improving growth rates in fish and shellfish through precise genetic alterations. Despite its potential, CRISPR/Cas9 implementation faces considerations and challenges, such as off-target effects, regulatory acceptance, ethical concerns, and ecological impacts. Emerging genetic technologies like Perturb-seq represent the next generation of genome editing, allowing high-resolution mapping of genetic networks and understanding of host–pathogen interactions at the cellular level. We present the Perturb-seq as the next breakthrough technique which will facilitate the identification of disease resistance mechanisms, virus entry receptors, and critical immune responses, offering pathways for novel drug targets. Complementary approaches like RNA interference (RNAi) and microbiome engineering further enrich strategies to improve aquaculture health. Future directions point towards an integrated use of CRISPR/Cas9, Perturb-seq, and microbiome engineering to sustainably revolutionise aquaculture health management.

Pages: 19

Aquaculture has emerged as a vital solution to meet the increasing global demand for high-quality protein. However, the sustainability of this rapidly growing sector is threatened by frequent disease outbreaks, leading to significant economic losses and environmental challenges. Traditional disease management strategies such as antibiotics, vaccines, and chemical treatments have provided some relief. But, they are increasingly associated with adverse effects, including the development of antimicrobial resistance and environmental degradation, as well as increased cost of production and acceptance by farmers and consumers. Breeding for disease-resistant aquaculture species presents a promising and sustainable alternative that aligns with global efforts to enhance food security by reducing production costs and environmental footprints. This chapter explores the future directions in breeding for disease resistance in aquaculture, focusing on innovative tools and technologies that can transform breeding programs. Advances in genomic technologies, such as genome-wide association studies (GWAS), marker-assisted selection (MAS), and genome editing (GE), have opened new possibilities for precise and efficient selection of disease-resistant traits. Emerging fields, such as epigenetics and microbiome manipulation, further highlight the potential of non-genetic approaches to enhance disease resistance. Coupled with bioinformatics and artificial intelligence (AI), these tools provide unprecedented opportunities for integrating big data and predictive analytics into breeding programs. Key challenges are critically examined, including balancing disease resistance with other production traits, maintaining genetic diversity, and addressing ethical and regulatory concerns. This chapter highlights advancements in breeding for disease resistance in aquaculture, emphasizing improvements in traditional breeding techniques and emerging technologies with insights that will drive innovation, boost productivity, and ensuring a more sustainable and secure global aquaculture industry.

Pages: 24

The emergence of antimicrobial resistance (AMR) and the limitations of conventional therapies have necessitated innovative approaches to disease management. This study explores the synergistic potential of bacteriophage therapy and nanotechnology in addressing infectious diseases, focussing on their applications in targeted drug delivery, diagnostics, and therapeutic interventions. Bacteriophages, viruses that specifically infect bacteria, offer a promising alternative to antibiotics by selectively targeting pathogenic bacteria while sparing the host microbiome. When combined with nanotechnology, their efficacy is significantly enhanced through improved delivery mechanisms, increased stability, and precise targeting. This research highlights the development of bacteriophage–nanoparticle (NP) conjugates, such as phage-loaded polymer NPs and gold-NP-based phage systems, for the treatment of multidrug-resistant bacterial infections, including methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. Additionally, nanotechnology enables the use of bacteriophages as diagnostic tools by integrating them with quantum dots and carbon nanodots for sensitive detection of bacterial pathogens. The study also examines the role of nanotechnology in overcoming challenges associated with bacteriophage therapy, such as limited host range and rapid clearance by the immune system, through surface modifications and encapsulation techniques. By underpinning disease management with these advanced applications, this research demonstrates a transformative approach to combating infectious diseases, offering a pathway towards sustainable and effective therapeutic strategies in the face of growing global health challenges.

Pages: 26

Aquaculture plays a vital role in global food security, providing nutrition to billions and contributing significantly to the economy of many countries. As the sector grows, particularly in regions like India, the need to address health challenges in farmed species becomes critical. The major challenge is to control diseases caused by members of Aeromonas, Klebsiella, Edwardsiella, Vibrio, Pseudomonas, and other bacterial species, which result in substantial economic losses. The intensification of farming practices exacerbates these problems, leading to increased pathogen load and greater reliance on antibiotics. However, the overuse of antibiotics contributes to the development of antimicrobial resistance (AMR), complicating disease management with some strains emerging as multiple antibiotic resistant. This has driven interest in alternative strategies, with the latest being phage therapy and quorum quenching (QQ). Phage therapy employslytic bacteriophages, primarily with a DNA genome, to target specific bacterial pathogen(s), provide a promising, highly selective, and self-replicating solution. On the other hand, QQ disrupts bacterial communication systems established via quorum sensing (QS), which regulates biofilm formation and virulence factor expression in pathogens. By targeting these systems, QQ reduces bacterial virulence without killing the bacteria directly, thus avoiding selective pressure and lowering the chances of resistance development. Both phage therapy and QQ represent eco-friendly, innovative alternatives to antibiotics, with the potential to reduce disease impact in aquaculture. This chapter explores these strategies in depth, examining their mechanisms, applications, and effectiveness in combating bacterial infections in aquaculture and discusses the challenges and prospects for their integration into sustainable farming practices.

Pages: 82

No chapter abstract available.

Pages: 19

The global aquaculture industry faces significant challenges due to the increasing prevalence of infectious diseases that threaten fish health and productivity. Vaccination has emerged as a critical strategy to mitigate these risks, enhancing the overall resilience of aquatic species. This chapter explains into the historical context of aquatic vaccines, tracing their evolution from traditional methods to cutting-edge biotechnological innovations. Aquatic vaccines play a pivotal role in enhancing the health and productivity of aquaculture species. This chapter provides a comprehensive overview of the current status of aquatic vaccines, highlighting their development, application, and efficacy in combating prevalent aquatic diseases. It explores the challenges faced in vaccine formulation and delivery, including antigen selection, adjuvant utilization, and the unique physiological characteristics of aquatic organisms. Furthermore, the chapter discusses emerging technologies such as DNA and RNA vaccines, recombinant proteins, and the potential of nanotechnology in vaccine development. By evaluating the existing literature and recent advancements, this chapter aims to illustrate the future prospects of aquatic vaccines, underscoring their significance in sustainable aquaculture practices and food security. The future of aquatic vaccines is promising, with ongoing research aimed at harnessing genetic engineering, genomics, and proteomics to design next-generation vaccines. Collaborations between academic institutions, industry stakeholders, and regulatory bodies will be vital in translating scientific discoveries into practical applications. The chapter concludes by discussing the importance of sustainable aquaculture practices, emphasizing how effective vaccination strategies can contribute to food security and the economic viability of aquaculture enterprises worldwide.

Pages: 20

Fish vaccination is important in promoting fish health and supporting sustainable aquaculture practices. As the aquaculture industry expands, there is an increasing need for effective and efficient disease management strategies to minimize economic losses and environmental impact. Fish vaccines serve as a preventive measure that strengthens immune responses, reduces dependency on antibiotics, and mitigates the risk of disease outbreaks, contributing significantly to the overall productivity and welfare of fish stocks. Adopting vaccination practices in aquaculture can enhance resistance to various pathogens, including viral, bacterial, and parasitic agents common in densely populated fish farms. By preventing infections, vaccines contribute to improved fish survival rates and quality, leading to increased profitability for producers and greater food security. However, several challenges hinder the widespread adoption of fish vaccination. One of the primary hurdles is the complexity of vaccine administration, particularly in larval or juvenile fish, where manual vaccination is impractical and labor-intensive. Additionally, the lack of robust adjuvants that can enhance vaccine efficacy remains a limitation, particularly for aquaculture vaccines, where a strong, long-lasting immune response is needed. A limited understanding of mucosal immunity, which is critical for pathogen defense in aquatic environments, also poses a challenge, as most pathogens invade through the gills, skin, or gastrointestinal tract. Moreover, environmental factors like water temperature, pH, and salinity can influence vaccine efficacy, as these parameters affect fish immunity and pathogen behavior. Commercialization challenges further complicate the scenario, with high costs and stringent regulatory hurdles limiting the availability of vaccines suited to diverse fish species and farming environments. Addressing these challenges requires ongoing advancements in vaccine technology and administration methods. Research into novel adjuvants, alternative delivery systems such as oral or immersion vaccines, and an improved understanding of fish immune mechanisms is essential for enhancing vaccine effectiveness. Future directions in fish vaccination will likely focus on developing more targeted vaccines optimized for specific pathogens and fish species and integrating vaccination within holistic fish health management strategies. By advancing these efforts, the aquaculture industry can move toward a more sustainable and resilient future, ensuring the health and productivity of farmed fish while reducing the environmental impact and reliance on chemical treatments.

Pages: 20

Aquaculture faces mounting disease challenges due to high-density farming and environmental stressors, driving the need for effective fish vaccination strategies. This chapter provides a comprehensive overview of teleost immunology in the context of disease prevention, spanning innate and adaptive responses, mucosal versus systemic immunity, and the generation of immunological memory. We discuss the cellular and molecular underpinnings of host–pathogen interactions, including the roles of phagocytes, cytokines, B and T lymphocytes, and immunoglobulin isotypes (IgM, IgD, IgT). The mechanisms of vaccine-induced protection are examined across delivery routes (injection, immersion, oral) and vaccine platforms (inactivated, live attenuated, subunit, DNA, RNA). Case studies highlight discrepancies between laboratory and field efficacy, emphasizing the influence of environmental variables and host genetics. Finally, we explore emerging technologies – including nanoparticle-based delivery, immunoinformatics-guided design, and thermostable formulations – that are reshaping the future of fish vaccines. This chapter aims to bridge foundational fish immunology with practical vaccinology, offering a mechanistic and applied framework to support sustainable aquaculture.

Pages: 21

Currently, the number and variety of approved aquatic vaccines worldwide are relatively limited, and they cannot fully cover the major diseases of relevant farmed species. Inadequate supply of efficient vaccines limits the overall effect of immunization against infectious agents and reduces farmers’ trust in the industrial application of vaccines. Still, the “in farm” vaccination of fish has become a standard operative procedure in most countries in Europe and North America. In Asia, Africa, and South America, with some exceptions like Japan and Chile, vaccines are not commonly used for fish disease control. This is apparently not consistent with the relevant amounts of fish that are produced in these areas. There are several reasons explaining the present situation. Most of the farms operate on a small scale with little technical support. Farmers are increasingly oriented toward prevention; despite this, treatment with antibiotics remains a necessary tool, even if with important differences between countries in terms of availability and local regulations that authorize their use. Moreover, the commercialization and field application of vaccines require a great investment of time and resources. Important issues have to be considered in order to guarantee the effective full “in field” delivery of vaccination protocols worldwide: the level of technology and good management reached in the target farm; the prompt identification of the disease causing agent or agents and, of course, the availability of adequate vaccine formulations; the identification of earliest time and of available windows for vaccination; the efficacy and safety of the product, preferably applicable to multiple fish species; a good return on the investment by the fish farmer; the public perception of consumers favoring vaccine use versus antibiotics (aiming at the limitation of antibiotic residues and of antimicrobial resistance (AMR) phenomena). The present chapter will provide a critical outlook on what is currently applied, in terms of in-field vaccination, by countries more or less developed, where aquaculture has a relevant role in the economy. The vaccination approach may include technologically advanced protocols, such as those applied in North America or in northern Europe, where farmers and vets dispose of multivalent formulations including several antigens, administered automatically with very efficient machinery, but also very simple protocols in which formulations are bacterins including a single pathogen, administered by syringes or injection guns managed by individual operators. Also, the formulations designed may deeply vary accordingly to the level of refinement achievable (inactivated pathogens versus DNA- or RNA-based vaccines) or accordingly to single countries’ current regulations and approved formulas. Several European countries, such as Italy, where the application of fish vaccination is quite common, even if not always technologically advanced, are promoting the production and periodical use of autogenous vaccines. These formulations are specifically tailored on the needs of single farms since they are developed using strains isolated from the same farm to which the vaccine will be addressed, and we think that this approach might be advantageous both in extended farms and in small-scale farms, in order to protect freshwater and marine species from bacterial/viral infections. The beneficial aspects as well as the limits of multimodal approaches of vaccination will be discussed in the light of the novel formulations development and on the modes of administration to fish.

Pages: 70

No chapter abstract available.

Pages: 13

Animal welfare in aquaculture is multifaceted, encompassing legal, ethical, and practical challenges. Aquaculture has grown significantly in recent years, contributing to global food security and offering economic opportunities. However, this growth has sparked debates around the welfare of animals in fish farming, as specific welfare information is only available for a mere 30% of species. This chapter discusses the complexities of animal welfare in aquaculture, highlighting the need for a holistic approach to welfare assessments. This involves a combination of behavioral, physiological, and environmental assessments to differentiate between health and positive welfare or disease and stress status. It also underscores the necessity of distinguishing between the effects of stress and overall welfare, noting that the onset of a disease does not necessarily equate to poor welfare status. Various stressors in aquaculture, such as poor water quality, handling and transportation, crowding, high pathogen pressure, environmental changes, noise, critical social interactions, and inappropriate nutrition, are explored. Identifying and mitigating these stressors is vital for enhancing fish health and welfare. This chapter also discusses the role of technological innovations in promoting animal welfare. Innovations such as artificial intelligence and monitoring systems could help monitor and improve animal welfare in real time in the future. However, implementing these technologies must be accompanied by suitable management practices, regular monitoring, and the creation of optimal environmental conditions. The need for international efforts for stricter legislation and cooperation between science, politics, and industry to further advance animal welfare in aquaculture is emphasized. The chapter also highlights the role of the FAO in advocating for countries to adopt the Blue Transformation Roadmap as a catalyst for change in aquatic food systems, aiming to achieve sustainable growth in aquaculture, effective fisheries management, and enhanced value chains. In conclusion, ensuring the welfare of fish in aquaculture requires a transformative shift within the industry, leveraging innovative technologies and sustainable practices. Addressing this complex issue requires a multifaceted approach involving legal, ethical, and practical considerations. With the right strategies and commitment, it is possible to ensure the welfare of aquatic animals in aquaculture, contributing to the sustainability of the sector and the quality of the products.

Pages: 26

Aquaculture is current requirement and preference, while also being ecologically, socially, and economically sustainable in order to supply for the long term. Environmentally sustainable production is required to preserve the productivity and diversity of food resources and ecosystems that support them, as well as to guarantee that the effects of food production do not jeopardize other ecosystem functions. The communities, industries, and supply chains that produce food must continue to operate and offer socially and morally acceptable working conditions for their employees, which requires socially and economically sustainable production. The economy depends heavily on the fishing industry. About 200 million people rely on ocean fishing as their primary source of income, making it a source of employment (Gareth, 2001). For some 950 million people globally, fish is their main source of protein, and for many more, it plays a significant role in their diet. The relationship between population increases and total consumption has been hypothesized by several researchers over the years 1970–2010 (FAO, 2000b; Delgado et al., 2002; Tacon, 2003). The average amount of fish consumed globally per person has nearly quadrupled in less than 50 years (World Fish Centre [WFC], 2002). About 16% of the animal protein consumed by humans worldwide comes from fish, which are also a great source of minerals and vital fatty acids. The main dietary source of omega-3 fatty acids for humans is fish. According to Crawford and March (1989), omega-3 fatty acids are essential nutrients for a baby’s healthy brain and eye development and can help prevent a variety of human diseases, including depression, lupus, cardiovascular disease, and other mental illnesses. While Asia dominates both aquaculture and capture fisheries, India is one of the world’s top producers of aquaculture, with over 13 lakh tonnes produced year (FAO, 2011).

Pages: 13

Aquaculture has reached new heights in recent years, which helps overcome the world’s protein needs. Efforts have been put forth to increase production using various techniques. Disease management is crucial in the aquaculture industry. Chemicals and antibiotics were excessively used to reduce the outbreak of diseases. This can lead to unwanted exposure of antibiotics to the environment. Alternate methods have been introduced to overcome this issue and maintain the species’ and surroundings’ health. Prebiotics and probiotics play a significant role in fish health through the beneficial bacteria that come with fermented food. It directly impacted the immune system of fish health by activating immune system response cells like phagocytosis and activation of neutrophils. Immunosaccharides present in the probiotics directly affect the fish’s immune system. Certain probiotics were designed to express and deliver immune-modulatory molecules. Live beneficial microbes were mixed with suitable substrate (probiotics complementary and probiotics synergistic). They promote overall health and help fight degenerative and non-transmissible diseases. This review summarizes recent research on using prebiotics, probiotics, and synbiotics in fish aquaculture, mainly focusing on enhanced growth, better immune response, and developing disease resistance.

Pages: 16

Annual catch limits