Aquaculture and Fish Welfare: Are the Rights of Fish Compromised?/ Akwakultura I Dobrostan Ryb: Czy Prawa Ryb Są Szanowane?

Doctor fish, beauty centres and public health: three keywords for a possible marriage to respect fish welfare and human health

Artisanal fishers in developing world are unaware that fish are capable of suffering or discomfort, though researches have shown that fish do feel pain. Five fish welfare domains have been identified which constitute their rights in their environment. The needs of wild fish are usually provided in their natural, undisturbed and unperturbed aquatic environment, of which the fish will prefer. However, various anthropogenic activities by humans (including artisanal fisheries itself) and some natural perturbations in the watershed, riparian zone, water body of the fish habitat and on the fish tend to take away these needs thereby compromising the fish welfare. These activities include environmental degradation, boat/canoe building, use of motorized engine boats/canoes, use of active and passive fishing gears, obnoxious cultural, religious and social fishing practices, fish harvesting, handling and processing among others. One way to understand the welfare needs of an individual fish is to understand its biology. Poor welfare conditions could then be assessed by how far the individual fish has deviated from the normal conditions. Non-intrusive signs based on the health, behavior, morphological anomalies, swimming, reduction in population and growth, outbreak of parasitic infections, injuries and loss of condition can be used to assess fish whose welfare has been compromised. Artisanal fishers should not only be concerned with catch, but, also the welfare of the fish being caught. This is because if the welfare of the fish is compromised, it is going to definitely affect the catch. As indispensable as fish is to humans, humans should not derive its pleasure at the expense of fish suffering. Human activities that impinge on the welfare of wild fish may not necessarily be stopped, but at least minimized in order to have continued sustainable artisanal exploitation of the fisheries. Keywords: welfare, artisanal fisheries, developing world, stress, behaviour, feel, habitat

Artisanal fishers in the developing world are unaware that fish are capable of suffering or experience discomfort, though researches have shown that fish do feel pain. Five fish welfare domains have been identified which constitute their rights in their environment. The needs of wild fish are usually provided in their natural, undisturbed and unperturbed aquatic environment, of which the fish will prefer. However, various anthropogenic activities by humans (including artisanal fisheries themselves) and some natural perturbations in the watershed, riparian zone, water body of the fish habitat and on the fish tend to take away these needs thereby compromising the fish welfare. These activities include environmental degradation, boat/canoe building, use of motorized boats/canoes, use of active and passive fishing gear, obnoxious cultural, religious and social fishing practices, fish harvesting, handling and processing among others. One way to understand the welfare needs of an individual fish is to understand its biology. Poor welfare conditions can then be assessed by how far the individual fish has deviated from the normal conditions. Non-intrusive signs based on the health, behaviour, morphological anomalies, swimming, reduction in population and growth, outbreak of parasitic infections, injuries and loss of condition can be used to assess fish whose welfare has been compromised. Artisanal fishers should not only be concerned with catch, but, also the welfare of the fish being caught. This is because if the welfare of the fish is compromised, it is going to definitely affect the catch. As indispensable as fish are to humans, humans should not derive their pleasure at the expense of fish suffering. Human activities that impinge on the welfare of wild fish may not necessarily be stopped, but should at least minimized in order to have continued sustainable artisanal exploitation of the fisheries.

12 - Stress Management and Welfare

Aquaponics is the combination of aquaculture (fish) and hydroponic cultivation of plants. This review examines fish welfare in relation to rearing water quality, fish feed and fish waste and faeces to develop a sustainable aquaponic system where the co-cultured organisms, fish, bacteria in biofilters and plants, should be considered holistically in all aquaponics operations. Water quality parameters are the primary environmental consideration for optimizing aquaponic production and for directly impacting fish welfare/health issues and plant needs. In aquaponic systems, the uptake of nutrients should be maximised for the healthy production of the plant biomass but without neglecting the best welfare conditions for the fish in terms of water quality. Measures to reduce the risks of the introduction or spread of diseases or infection and to increase biosecurity in aquaponics are also important. In addition, the possible impacts of allelochemicals, i.e., chemicals released by the plants, should be taken into account. Moreover, the effect of diet digestibility, faeces particle size and settling ratio on water quality should be carefully considered. As available information is very limited, research should be undertaken to better elucidate the relationship between appropriate levels of minerals needed by plants, and fish metabolism, health and welfare. It remains to be investigated whether and to what extent the concentrations of suspended solids that can be found in aquaponic systems can compromise the health of fish. Water quality, which directly affects fish health and well-being, is the key factor to be considered in all aquaponic systems.

Aquaculture production continues to increase to satisfy global demand, and as such, issues relating to its environmental sustainability and the welfare of fish are becoming more prominent within society. Sterile triploid fish (possessing one additional chromosome set to the more natural diploid state) are in use in aquaculture and fisheries management to avoid the problems associated with unwanted early sexual maturation and genetic interactions between wild and cultured fish. Triploids are physiologically and behaviorally similar to diploids, although ploidy effects do exist. This review focuses on the welfare of triploid fish within aquaculture and fisheries management. The main conclusions are that triploids appear more susceptible to temperature stress, have a higher incidence of deformities, and are less aggressive than their diploid counterparts. However, considerable knowledge gaps exist in triploid physiology and performance; therefore, triploid requirements for water quality, nutritional requirements, stocking densities, and slaughter methods cannot be fully assessed. In addition, other than growth and survival, no information exists on the performance of triploids when released into natural environments, and this is of considerable concern, as triploids are commonly used in catch-and-release fisheries. These matters become more pressing with today's increased emphasis on animal welfare.

There is a considerable public and scientific debate concerning welfare of fish in aquaculture. In this review, we will consider fish welfare as an integration of physiological, behavioral, and cognitive/emotional responses, all of which are essentially adaptative responses to stressful situations. An overview of fish welfare in this context suggests that understanding will rely on knowledge of all components of allostatic responses to stress and environmental perturbations. The development of genomic technologies provides new approaches to this task, exemplified by how genome-wide analysis of genetic structures and corresponding expression patterns can lead to the discovery of new aspects of adaptative responses. We will illustrate how the genomic approach may give rise to new biomarkers for fish welfare and also increase our understanding of the interaction between physiological, behavioral, and emotional responses. In a first part, we present data on expression of candidate genes selected a priori. This is a common avenue to develop molecular biomarkers capable of diagnosing a stress condition at its earliest onset, in order to allow quick corrective intervention in an aquaculture setting. However, most of these studies address isolated physiological functions and stress responses that may not be truly indicative of animal welfare, and there is only rudimentary understanding of genes related to possible cognitive and emotional responses in fish. We also present an overview on transcriptomic analysis related to the effect of aquaculture stressors, environmental changes (temperature, salinity, hypoxia), or concerning specific behavioral patterns. These studies illustrate the potential of genomic approaches to characterize the complexity of the molecular mechanisms which underlies not only physiological but also behavioral responses in relation to fish welfare. Thirdly, we address proteomic studies on biological responses to stressors such as salinity change and hypoxia. We will also consider proteomic studies developed in mammals in relation to anxiety and depressive status which may lead to new potential candidates in fish. Finally, in the conclusion, we will suggest new developments to facilitate an integrated view of fish welfare. This includes use of laser microdissection in the transcriptomic/proteomic studies, development of meta-analysis methods for extracting information from genomic data sets, and implementation of technological advances for high-throughput proteomic studies. Development of these new approaches should be as productive for our understanding of the biological processes underlying fish welfare as it has been for the progress of pathophysiological research.

Introduction. In the conditions of anthropogenic pollution of water, environment-safe drugs and implementing of immunomodulatory drugs are becoming increasingly common. Schemes of their use in fisheries are being developed. The article presents and analyzes the potential use of biologically active additives (BAA), namely probiotics, prebiotics and yeasts, both domestically and internationally produced, in terms of their effect on the fish body. Materials and methods of research. Search for literature data on the use of biologically active substances in fish farming, namely probiotics, prebiotics and yeast. Research results. Considering the negative impact of prophylactic and therapeutic use of antibiotics in aquaculture, the use of dietary immunostimulants has been proposed as an alternative to antimicrobial drugs. In this sense, functional dietary supplements, including pre-, probiotics and yeasts, are receiving increasing attention as an environmental strategy to improve fish health. Probiotics are the objects of comprehensive scientific research and an important product on the world market. The use of probiotics as biocontrol agents in aquaculture is increasing. The benefits of such additives include increased nutritional value, inhibition of pathogens and enhanced immune response by increasing white blood cells and phagocytosis. They improve the quality of the growing environment, protect fish from biological hazards, and modulate physiological processes that ultimately contribute to the health and welfare of fish in aquaculture. Probiotics also enhance growth performance and feed utilization in aquatic animals by increasing the activity of digestive enzymes. The beneficial effects of prebiotics are due to by-products resulting from the fermentation of intestinal commensal bacteria. Among the many health benefits attributed to prebiotics is the modulation of the immune system. They directly enhance the innate immune response, including activation of phagocytosis, neutrophils, alternative complement system, and increased lysozyme activity. Another environmentally friendly product that has been proposed as a dietary supplement is yeasts. Research on yeast products in fish diets has focused on their role in nutritional and functional supplements that contribute to the immune responses and gut health of fish. Conclusions. Various studies of pro- and prebiotics in fish have shown the following results: effects on growth, gut microbiota, resistance to pathogenic bacteria and parameters of innate immunity such as alternative complement activity (ACH50), lysozyme activity, natural hemagglutination activity, respiratory burst, superoxide dismutase activity and phagocytic activity.All the above studies demonstrate that the addition of nutritional supplements to feed, such as immunostimulants, is an alternative method for the prevention and control of various diseases in aquaculture.

Pigment matters: Behavior and lateralization of albino and pigmented fish (Bronze Corydoras) in aquaculture

Physical enrichment for improving welfare in fish aquaculture and fitness of stocking fish: A review of fundamentals, mechanisms and applications

Fish welfare issues are increasingly appearing on social and political agendas and have recently gained prominence in fisheries literature. By focusing on examples from recreational fishing, this paper challenges some of the previous accounts of fish welfare. Issues of concern encompass: (1) the feelings‐based approach to fish welfare; (2) the artificial divide between human beings and nature; and (3) ways in which stakeholders can address fish welfare issues. The different approaches to characterizing the interaction of humans with animals are animal welfare, animal liberation and animal rights. We show that the suffering‐centred approaches to fish welfare and the extension of the moral domain to fish – characteristic of the concepts of animal liberation and animal rights – are not the cornerstone of animal welfare. This, however, does not question the need of fisheries stakeholders to consider the well‐being of fish when interacting with them. There are many ways in which recreational fishing stakeholders can modify standard practices to improve the welfare of fish, without questioning fishing as an activity per se. Examples are choice of gear and handling techniques. Previous accounts have failed to include discussions of the many efforts – voluntary or mandated – pursued by fisheries stakeholders to reduce fish stress, injury and mortality. Progress towards addressing fish welfare issues will be enhanced by avoiding the viewing of humans as ‘non‐natural’ disturbance to fishes and keeping three types of crucial question in separate compartments. The three questions cover the symptoms of good and poor welfare, the conscious experience of suffering, and the ethical attitudes towards animals. Fish biologists should focus on the first question – objective measurement of biochemical, physiological and behavioural indicators – to evaluate whether human interactions with fish impair the latters’ health or prevent them from receiving what they need, if held in captivity.

Skin mucus metabolites in response to physiological challenges: A valuable non-invasive method to study teleost marine species

Impact of environmental enrichment and social group size in the aggressiveness and foraging activity of Serrapinnus notomelas

Lumpfish (Cyclopterus lumpusL) is a North Atlantic species harvested for its roe and increasingly used as a cleanerfish in Atlantic salmon (Salmo salarL.) farming to remove salmon louse (Lepeophtheirus salmonis). In aquaculture, the health and welfare of fish depends on optimal levels of several biotic and abiotic factors. Crowding, a common abiotic stress factor in aquaculture practice, can affect the welfare and survival of fish. In this study, lumpfish was exposed to crowding stress daily at random timepoints for one month (stress group) or no crowding (control group). Blood and skin were sampled weekly for physiological parameter analysis and proteomics, respectively. Adrenocorticotropic hormone (ACTH) stimulation and dexamethasone (DEX) suppression test were conducted at the sampling timepoints. Gel-based proteomics coupled with liquid chromatography and tandem mass spectrometry (LC-MS/MS) was used to identify protein changes in skin tissues of lumpfish under crowding. The results indicated that the stress group showed signs of allostatic overload type 2 (chronic stress) due to oversensitivity to ACTH, and a reduced negative feedback system with increased baseline levels of cortisol. These chronic changes in the endocrine system promoted changes in secondary and tertiary stress responses as reduced osmoregulatory capacity and stunted growth, after 14 days of stress and onward. Calmodulin, guanine nucleotide binding protein subunit beta 2, glutathione-S-transferase Mu 3, fatty acid binding protein, heat shock cognate 70 kDa protein, keratin, histone H4 and 14-3-3 alpha/beta showed protein spot intensity changes compared with controls in lumpfish skin at one or several time points during the one month period of crowding stress. The differentially expressed proteins are related to several metabolic pathways and are involved in stress and immune responses. Overall, the study shows that lumpfish can suffer from chronic stress with possible dire consequences for the animal welfare.

Environmental enrichment (EE) can improve the welfare of captive fish. Its objective is to provide new sensorial and motor stimulation in order to help meet their behavioural, physiological, morphological and psychological needs, whilst reducing stress and frequency of abnormal behaviours. In fish farms, rearing environments are usually designed from a human perspective and based on economic requirements, mainly for practical reasons for the farmer, with little consideration for animal welfare. Throughout aquaculture production cycles, many farming operations can be stressful for fish, and EE may not only help them cope with these stressful events but also improve their overall welfare. In recent years, increasing interest on the effects of EE in captive fish has focussed mainly on structural enrichment. However, there are many other enrichment strategies that merit attention (e.g. sensorial, occupational, social and dietary enrichment) and which may be of interest for fish farming. Here, we review in depth the existing literature on EE and its effects on the welfare of a wide range of farmed fish species, discussing the feasibility and potential applications of different EE strategies to promote fish welfare at a commercial scale. We also present a practical framework to address the design, validation and implementation of EE by the aquaculture industry, taking in consideration the technical challenges of providing enrichment for farmed fish.