Husbandry

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Harvest and Slaughter

Akse L, Midling K (2000) Slaughtering of Atlantic Halibut (Hippoglossus hippoglossus): Effect on Quality and Storing Capacity. In:  Farmed Fish Quality. Eds: Kestin SC, Warris PD.  Blackwell Science Inc.  448 pp.   
NAL Call No.  SH151 F37 2001
Through 15 years of intensive biological research, Atlantic halibut is now established as the most promising species in Norwegian marine aquaculture. Annual production is still small, but is expected to grow rapidly. However, knowledge on muscle quality and what factors affect the product in this species are scarce. In this project a number of experiments were conducted on farmed Atlantic halibut. Except for the initial pH, we were not able to detect major differences in post-mortem quality between the stressed and not stressed halibut. Compared to several other species, Atlantic halibut has exceptional storing capacity both in sensory, chemical and microbiological terms. In this experiment, this is demonstrated by almost no development in pH, TVBN and viable bacteria values until after day 21. Farmed Atlantic halibut is likely to be accepted in the market as fresh fish at least one week longer than other white fish species (e.g. cod). CO₂ performed poorly as an anaesthetic and resulted in rapid onset of rigor mortis and high hardness values. Eugenol postponed onset of rigor mortis by 14 to 16 hours compared to CO₂ and gave a significantly lower measured hardness. Killing by a blow to the head resulted in increased variation in onset time and development of rigor mortis. Small differences were found in haem iron muscle residues among the groups, but halibut killed by a blow to the head were significantly better bled than fish anaesthetized with CO₂. 
Descriptors:  fish culture, seafood, quality control, slaughter, fish storage, storage life, Hippoglossus hippoglossus, Atlantic halibut
ASFA; Copyright © 2003, FAO

Annonymous.  (1997) Welfare of fish at slaughter. Trout News. 24:42-44
The report of a workshop sponsored by the Humane Slaughter Association and the British Trout Association. The industry view, the veterinary view, research on slaughter methods, and industry requirements were covered.
Descriptors:  fisheries, slaughter, animal welfare 
ASFA; Copyright © 2003, FAO

Bernoth EM, Wormuth HJ (1991) Tierschutzaspekte bei der Toetung von Fischen. [Aspects of animal welfare in killing fishes.]  Bundesgesundheitsblatt. 34(1):8-10  (In German) ISSN: 0007-5914
Descriptors:  fishes, destruction of animal, slaughtering, animal welfare, animal health, animals, aquatic animals, aquatic organisms, harvesting,  methods, processing

Bernoth EV (1990) Schaedigung von Fischen durch Turbinenanlagen. [Fish damage by turbines.]  Deutsche Tieraerztliche Wochenschrift. 97(3):161-164  (In German with English summary)
NAL Call No.  41.8 D482
Descriptors:  fishes, lesions, water power, machinery, animal welfare, animal health, animals, aquatic animals, aquatic organisms, energy sources, equipment, injurious factors,  natural resources

Bernoth EM von, Wormuth HJ (1990) Tierschutzaspekte bei der Toetung von Fischen. [Animal protection aspects on killing of fish.]  Deutsche Tieraerztliche Wochenschrift. 97(4):154-157  (In German with English summary)
NAL Call No.  41.8 D482
According to the Animal Protection Law (1986) fish are to be killed by methods which do not cause pain. However, the regulations do not cover the killing of non-food fish. A questionnaire, conducted among 85 fish scientists, revealed that single fish should be killed by a blow on the head, and larger numbers by electrical methods or by use of chemicals. Decapitation was proposed for eels. A regulation from 1936 stipulates the methods for the slaughtering of food fish. Mechanical or electrical stunning is compulsory except for eel and flatfish. The questionnaire showed that in general the present legal regulations are sufficient for the slaughtering of fish with the exception of eels. The commercially available apparatus for stunning and killing do not always fulfill the requirements of animal protection, slaughtering technology and safety for the user. Official testing of these apparatus as well as the evaluation of new methods - like CO₂ -stunning - are necessary in order to prevent the use of methods which are feasible, but do not fulfill animal welfare, especially for eel.
Descriptors:  fishes, slaughtering, destruction of animals, animal welfare, animal health, animals, aquatic animals, aquatic organisms, harvesting, methods, processing, government policy, mortality causes, commercial species, fishery technology, fish handling, processing fishery products, slaughter, fish, animal welfare
ASFA; Copyright © 2003, FAO

Bretzinger C (2001) Einfluss unterschiedlicher Betaeubungsmethoden auf Stressbelastung und Produktqualitaet bei der Regenbogenforelle (Oncorhynchus mykiss) [Influence of different pre-slaughter stunning methods on stress reaction and product quality of rainbow trout (Oncorhynchus mykiss)]. Muenchen FRG Hieronymus.  189 pp.  (In German)  Dissertation. (Dr. vet. med.); Incl. 20 pages refs.
In the present study the stunning of rainbow trout (Oncorhynchus mykiss) via pulsed direct current electroshock, carbon dioxide exposition without and with oxygen enrichment and anaesthesia with the fish anaesthetic AQUI-S in comparison to stunning with a blow on the head was examined with respect to animal welfare and product quality of fish as food. The aspect of animal welfare was assessed by determination of the parameters respiration, aversive reactions, mucus secretion and the time period until fish enter anaesthesia as well as the blood parameters adrenaline, noradrenaline and packed cell volume. Product quality was evaluated by registration of carcass lesions, hemorrhages and fillet colour. All five methods proved to be effective for anaesthesia of trout. The blow on the head is the preferable method to stun consumption-sized rainbow trout if only a small number of fish is to be slaughtered. The electroshock method was not suitable for stunning larger numbers of trout for a sufficient period of time. Introduction of pure CO₂ gas, respectively CO₂ and CO₂ into water, also had to be considered as not suited because the fish showed strong signs of dyspnoe and aversive reactions until entering anaesthesia for on average 10 min., respectively 12 min. Oxygen enrichment obviously did not reduce the stress influence on trout. Applying the fish anaesthetic AQUI-S in a dose rate of 25 ppm enabled to stun rainbow trout for the slaughtering process. During an average narcosis period of 9 min. no signs of dyspnoe or an aversive reaction were recorded. Therefore, AQUI-S can be recommended -- without considering food and drug legislation -- as an alternative method for stunning large amounts of fish, which fulfills the requirements of animal welfare. The blood parameters adrenaline and noradrenaline showed significant differences between the stunning methods. The blow to the head and anaesthesia with AQUI-S gave -- comparable with each other -- the lowest values for adrenaline and noradrenaline. At the end of electronarcosis intermediate amounts, after carbon dioxide exposition and CO₂/CO₂ narcosis the highest catecholamine concentrations were measured. The latter indicates a strong stress reaction. The packed cell volume values were lowest after percussive stunning. For the remaining methods higher values were determined. Visible alterations regarding the product quality of the carcasses were registered in trout being stunned by electroshock, which showed “current marks” and hemorrhages. The results of the colour measurements did not give hints on negative effects on product quality in dependence of the stunning method.
Descriptors:  slaughter, anaesthetics, quality assurance, human food Oncorhynchus mykiss
ASFA; Copyright © 2003, FAO

Coutant, C.C., Whitney, R.R (2000) Fish behavior in relation to passage through hydropower turbines: A Review.  Transactions of the American Fisheries Society. 129(2):351-380
NAL Call No.  414.9 Am3
We evaluated the literature on fish behavior as it relates to passage of fish near or through hydropower turbines. Our goal was to foster compatibility of engineered systems with the normal behavior patterns of fish species and life stages such that passage into turbines and injury in passage are minimized. In particular, we focused on aspects of fish behavior that could be used for computational fluid dynamics (CFD) modeling of fish trajectories through turbine systems. Salmon smolts approaching dams are generally surface oriented and follow flow. They can be diverted from turbines by spills or bypasses, with varying degrees of effectiveness. Smolts typically become disoriented in dam forebays. Those smolts drawn into turbine intakes orient vertically to the ceilings but are horizontally distributed more evenly, except as they are affected by intake specific turbulence and vortices. Smolts often enter intakes while oriented with their heads upstream, but they may change orientation in the flow fields of the intake. Nonsalmonids most often enter intakes from the vicinities of shorelines, and they do so episodically, which suggests accidental capture of schools (often of juveniles or in cold water) and little behavioral control during turbine passage. Models of fish trajectories should not assume neutral buoyancy throughout the time period during which a fish passes through a turbine, largely because of pressure effects on swim bladders and the resulting compensatory behavior. Fish use their lateral line system to sense obstacles and to change their orientation, but this sensory response system may not be effective in the rapid passage times and complex pressure regimes of turbine systems. The effects of preexisting stress levels on fish performance in turbine passage (especially as they affect trajectories) are not known but may be important. There are practical limits of observation and measurement of fish and flows in the proximity of turbines that may inhibit the development of much information that is germane to developing a more fish friendly turbine. We provide recommendations for CFD modelers of fish passage and for additional research.
Descriptors:  literature reviews, freshwater fish, anadromous species, migratory species, smolts, lateral line, orientation behaviour, biological stress, avoidance reactions, entrainment, hydroelectric power plants, rivers, fishways, fishery management, salmon fisheries, river fisheries, nature conservation, river engineering, reviews, animal welfare, human impact, hydropower turbines, fish passages, hydroelectric plants, fish behavior, literature review, salmon, turbines, fish migration, Salmonidae
ASFA; Copyright © 2003, FAO

Drawer K (1987) Die Praxis der Schlachttierbetaeubung aus der Sicht des Tierschutzes. [Animal welfare in stunning of slaughter-animals.]  Tieraerztliche Umschau. 42(11):878-885.  (In German)
NAL Call No.  41.8 T445
Descriptors:  domestic animals, stunning, animal welfare, animal health, animals, fishing methods, fishing operations, harvesting, methods, processing, slaughtering, fish welfare

Drawer K (1987) Das Schlachten von Tieren im geaenderten Tierschutzgesetz [Slaughtering of animals in the new animals welfare act]. Deutsche Tieraerztliche Wochenschrift.  94(2):106-107. (In German)
NAL Call No.  41.8 D482
Descriptors:  domestic animals, slaughtering, animal welfare, laws, stunning, animal health, animals, fishing methods, fishing operations, harvesting, legislation, methods, processing, slaughtering

Drosse H (1994) Die “Lebendhaelterung” gefangener Fische im Setzkescher. [Fish farming landing nets.] Rundschau fuer Fleischhygiene und Lebensmittelueberwachung. 46(9):207-209. ISSN: 0178-2010
Descriptors:  game fishes, angling, animal welfare, fish cages, legislation, fishing rights, aquaculture equipment, equipment, fishing methods, legal rights

Grandin T (1985) Cardiac arrest stunning of livestock and poultry.  Eds: Fox MW, Mickley LD.  Advances in Animal Welfare Science. Martinus Nijhoff, Dordrecht (Netherlands), 1986, p. 1-30
NAL Call No.  HV4701 A34
Descriptors:  livestock, poultry, stunning, heart, anatomy, animal anatomy, animals, birds, body parts, cardiovascular system, domestic animals, domesticated birds, fishing methods, fishing operations, harvesting, methods, processing, slaughtering, vertebrates

Gregory NG (1998) Animal Welfare and Meat Science. CAB International.Wallingford, OX10 8DE, UK.  298 pp. 
NAL Call No.  HV4731 G74 1998
It is recognised that careful and humane treatment of slaughter animals at the abattoir influences the quality of their meat, apart from humane considerations, and supporting evidence is assembled here. Correct slaughter procedure and appropriate abattoir installations are dealt with. There are separate chapters on cattle, sheep, pigs, poultry and fish, to deal with special requirements for each species.  
Descriptors: slaughter, livestock, fish, animal welfare, meat quality
Copyright © 2003, CAB International.

Gregory NG (1996) Welfare and hygiene during preslaughter handling. Meat Science 43 (suppl.):S35-S46 Massey University, Palmerston North, NZ.
NAL Call No. TX373.M4
Descriptors:  meat quality, slaughter, animal welfare, stress, abattoirs, carcass quality, damage, food hygiene, literature reviews, glycogen, muscles, metabolism, handling, fish, pigs, beef cattle

Kestin SC, Vis JW van de, Robb DHF (2002) Protocol for assessing brain function in fish and the effectiveness of methods used to stun and kill them. The Veterinary Record : Journal of the British Veterinary Association. 150(10):302-307
NAL Call No. 41.8 V641
Descriptors:  marine fishes, freshwater fishes, stunning, slaughter, animal welfare, brain, physiological functions, neurophysiology, evaluation, anesthesia, animal behavior

Kestin S (1993) Welfare of fish at harvest. Trout News. 17:28-30 
Descriptors:  fishes, fish culture, death, animal welfare, slaughter, Oncorhynchus mykiss, aquaculture, bony fishes, developmental stages, fish, salmonoidei

Knierim U (1996) Die Tierscutz-Schlachtverordnung. [The animal welfare regulations at slaughter.] Deutsche Tierarztliche Wochenschrift  103(2):52-54 (In German with English summary)
NAL Call No.  41.8 D482
The animal welfare regulation on the slaughter of animals, existing only as a draft for the time being, is designed not only to transpose EC-legislation into national law but also to update and strengthen preconstitutional national legislation on this matter. For a wide area related to the slaughter or killing of animals, animal welfare requirements are put in concrete terms. Among the topics belonging to this area are the theoretical and practical knowledge of the personnel, the handling of animals before slaughter or killing, stunning, the control of its efficacy and the permessibility of certain stunning or killing methods. Not only livestock but also, for example, fur animals and fish are concerned. In practice it will take some efforts in order to attain compliance with the provisions of the animal welfare slaughter regulation.
Descriptors: regulations, stunning, poultry, legislation, slaughter, animal welfare, cattle, pigs, sheep, fishes

Lambooij E, Vis JW, van de Kloosterboer RJ, Pieterse C (2002) Welfare aspects of live chilling and freezing of farmed eel (Anguilla anguilla): neurological and behavioural assessment.  Aquaculture. 210 (1/4):159-169
NAL Call No.  SH1A6
The overall objective of the study was to evaluate a slaughter method of eels, which consisted of chilling until their body temperature was <5 °C for stunning, and subsequently placing them in cold brine at -18°C for 15 min for killing. Three distinct experiments and a control were performed. First, 19 eels with an average live weight of 758 ± 44 g were restrained and equipped with EEG, ECG electrodes and a temperature sensor inside the body. Then, they were placed in the ice water. Indices for the induction of unconsciousness and insensibility were the appearance of theta and delta waves and no response on pain stimuli, which disappeared at a body temperature of 8.0 ± 2.1°C after 12 ± 5 min in 15 eels. The responses to pain stimuli did not disappear in three eels. Within a confidence level of 95%, the percentage of eels that was not effectively stunned during the procedure in ice water of <5°C was at least 5%. The heart rate decreased from 24 ± 10 beats/min (n=14) to 7 ± 4 (n=11) and became irregular during cooling down. When placed in the brine water of -18°C, the EEG showed rapid and extreme depolarization of the membranes, which started after 27 ± 17 seconds (n=18). The ECG showed fluttering of the heart in all eels. None of the eels recovered after this procedure. For 10 eels with an average live weight of 128 ± 27 g, it was observed that the body temperature decreased from 17.1 ± 0.6 to 4.0 ± 0.5°C in the ice water. After 15 min in the brine water of -16.1 ± 2.2°C, the body temperature decreased to -3.1 ± 2.3°C. Finally, three groups of 7 eels and 8 single eels were placed in ice water of -0.0 ± 0.1°C. The observation of unrestrained eels revealed four phases. Animals were (1) swimming around in the water, (2) attempting to escape from the ice water, (3) pressing their nose to the wall or corner while showing clonic muscle cramps, and finally (4) breathing only, while all other muscle activity was totally suppressed. Afterwards, they were transferred to cold brine at -18°C, and none of the eels recovered. The eight control eels, which were transferred to water at 18°C, swam around, except for one that was lying in an S-shape position at the bottom. After 570 and 605 seconds, two eels tried to escape from the box. The obtained results showed that the eels, which were transferred from water at 18°C to ice water, might be stressed, a specific behaviour and an irregular heart rate were observed. From an animal welfare point of view, it is therefore not recommended to stun eels by live chilling. Moreover, at least 5% of the eels will not be stunned at a body temperature of <5°C. Placing eels in brine water of -18°C is an effective method to kill the eels before slaughter. However, it cannot be recommended to place conscious eels in cold brine water, because it takes more than 27 seconds before unconsciousness may be induced.
Descriptors: animal behaviour, animal welfare, body temperature, chilling, freezing, heart rate, neurology, pain, slaughter, stunning, eels, Anguilla, Anguillidae, Anguilliformes, Osteichthyes, fishes, diadromous fishes, aquatic animals, aquatic organisms
Copyright © 2003, CAB International.

Marx H, Brunner B, Weinzierl W, Hoffmann R, Stolle A (1997) Methoden zur Betaeubung von Suesswasserfischen : Einfluss auf die Fleischqualitaet und Tierschutzaspekte. [Methods of stunning freshwater fish: impact on meat quality and aspects of animal welfare.]  Zeitschrift fuer Lebensmittel Untersuchung und Forschung.  204(4): 282-286   (In German with English summary)
NAL Call No.  TX341 Z45
Taking into account aspects of meat quality and animal welfare, three methods of stunning fish were compared: a manual technique (blow on the head, stab in the neck), one using electricity and one using CO₂. The following results were obtained using eel, carp and trout. From the viewpoint of animal welfare, the effects on the fish were judged. Exitation and mucus secretion as well as the time taken for the fish to be anaesthetized were recorded. With manual and electricalstunning, all fish were anaesthetized almost immediately, while using CO₂ it took 3.2 min (trout), 9.2 min (carp) and 109.7 min (eel) on average. After slaughter and after 3 and 8 days of storage on ice, the fish meat quality parameters, i.e. pH value, water-holding capacity and rigor mortis, were measured. CO₂ stunning gave rise to the lowest pH values and  water-holding capacities. Rigor mortis in carp and eel advanced the most. Testing of raw and prepared fish was performed by a panel assessing organoleptic properties. In many cases, fish anaesthetized manually were ranked to be better than those in the other groups.
Descriptors:  freshwater fishes, fish, stunning, time, quality, pH, water holding capacity, postmortem changes, organoleptic properties, animal welfare, eels, carp, trout, animal products, chemicophysical properties, diadromous fishes, fishery products, fishes, freshwater fishes, quality

Marx H, Brunner B, Weinzierl W, Hoffmann R, Stolle A. (1996) Comparative investigations on different methods for stunning fish with special regard to meat quality parameters.  Proceedings of the Conference of  IIR Commission  C2, Bordeaux Colloquium Refrigeration and Aquaculture Froid et Aquaculture Colloque de Bordeaux, compte  rendu de la reunion de la Commission C2 de l'IIF Paris France Institut International du Froid.  pp. 199-206 
NAL Call No.  TP490 S34
Taking into account aspects of meat quality and animal welfare, three methods for stunning fish were compared: manually (blow on the head, stab in the neck) with electricity and using CO₂. The following results were obtained for eel (n = 72), carp (n = 120) and trout (n = 54). From the view of animal welfare, the effects on the fish were judged. Excitation and mucus secretion, as weIl as the period of lime until the fish were in anaesthesia were recorded. With manual and electrical stunning, aIl fish were anaesthetized almost immediately, while using CO₂, it takes 3.2 min (trout), 9.2 min (carp) and 109.7 min (eel), on average. After slaughter, after three and eight days of storing the fish on ice, the meat quality parameters, pH value, water holding capacity and rigor mortis were measured. CO₂ stunning showed the lowest pH-values and water holding capacities; also, rigor mortis in carp and eel advanced most. Testing of raw and prepared fish was performed by a sensoric team. In many cases, fish anaesthetized manually were ranked better than the other groups. The findings indicate that CO₂ was not appropriate for stunning carp and eel. Electrical stunning, with some improvements, could meet the requirements of meat quality and animal welfare.
Descriptors:  processing fishery products, anaesthesia, slaughter, quality, Oncorhynchus mykiss, Cyprinus carpio, Anguilla anguilla
ASFA; Copyright © 2003, FAO

Muenkner W, Kuhlmann H, Oehlenschlaeger J (2000) Sensibilitaet von Seefischen an Bord.    Teil 2: Demersale und pelagische Fischarten aus Schleppnetzfaengen in der Nord  und Ostsee. [Investigations on the sensitiveness of sea water fish on board -- Part 2: Demersal and pelagic fish species of the North and Baltic Sea.]   Inf Fischwirtsch Fischereiforsch. 47(2):97-101  (In German)
The sensitiveness of different demersal and pelagic fish species of 70 hauls in the North and Baltic Sea in water depths of 60 to 250 m and 15 to 80 m, respectively, amount of catch of 100 to 3500 kg and trawling times of 0,5 to 6 h on board of the FRV Walther Herwig III was investigated. Some demersal fish species, e.g. saithe (Pollachius virens), were even still sensitive, when caught at a water depth of 250 m at a trawling time of 1,5 h. Generally the number of sensitive fishes was reduced with increasing water depth, amount of catch, trawling time and following storage of the catch on board. Among demersal fishes the species without swimbladder and flat fishes were clearly more resistent to mechanical stress. On the contrary, pelagic fish species were generally less robust. After trawling times of 2 h no sensitive animals were observed. In some fisheries there are mixed catches of demersal and pelagic fish species with different sensitiveness. In commercial fisheries, there is therefore  under animal welfare aspects for the time being, no prospect for an improvement of the catching and slaughtering procedure on board.
Descriptors:  biological stress, bottom trawls, midwater trawls, total mortality, Pollachius virens, Gadus morhua, Clupea harengus, Melanogrammus aeglefinus, ANE
ASFA; Copyright © 2003, FAO

Neukirch M (1994) Legal and animal welfare aspects of the killing of fish. [Uber rechtliche und tierschutzrelevante Aspekte bei der Totung von Fischen.] Deutsche Tierarztliche Wochenschrift (Germany). 101(8):316-319
NAL Call No.  41.8 D482  
The selection of methods for killing fish is determined by the number of fish to be killed, their utilization and the existing laws. No regulations exist for killing non-food fish. The methods for killing food-fish, however, are stipulated in a regulation from 1936. Mechanical or electrical stunning is obligatory except for flatfish and eel. Single fish should be stunned by a blow on the head, followed immediately by slaughtering or bleeding to be sure that the fish is really dead. When larger numbers of fish should be killed for food production only electrical methods are allowed as alternative. Chemicals can be used for killing non-food fish, the non-pollutant destruction of dead fish and chemical-contaminated water, however, has to be guaranteed. The methods are discussed with respect to practicability and animal welfare. 
Descriptors: animal welfare, fisheries, legislation and  jurisprudence, fishes, physiology, electric stimulation, Germany

Nowak D (1989) Tierschutzrelevante Aspekte bei Halterung, Verkauf und Totung von Susswasserspeisefischen. [Welfare aspects of the holding, selling and killing of freshwater fishes for food.] Rundschau fur Fleischhygiene und Lebensmitteluberwachung  41(7):139-140  (In German)
Descriptors: animal welfare, aquaculture, fish farming

Oehlenslager J, Kestin SC, Tejada M, Sorensen NK, Torrissen OJ, Nesvabda P, Van Rijsingen LCM (1998) Optimisation of harvest procedures of farmed fish with respect to qualify and welfare. Third European Marine Science and Technology Conference MAST Conference, Lisbon, 23 27 May 1998: Project Synopses Vol 6: Fisheries and Aquaculture FAIR: 1994 98, Selected Projects from the Research Programme for Agriculture and Fisheries including Agro Industry, Food Technology, Forestry, Aquaculture and Rural Development FAIR.  Luxembourg Luxembourg European Commission DG 12 Science, Research and Development.  6:244-245
In the last decade consumers have become much more aware of product quality. This also includes the production and processing of animals under humane conditions. The greater awareness has led to an increased focus by processors on the quality of farmed fish. For some fish species, harvest conditions, especially slaughter, have been reported to have an adverse affect on flesh quality. This may result from the effects of stress, for example when the killing method is not instantaneous, in which case the welfare of the fish will also be affected. Preliminary results indicate that methods which kill fish rapidly can result in an improvement in quality and a reduction of stress, thereby also leading to an improvement in welfare. The objectives of the proposed study are therefore twofold: (1) the optimisation of the slaughter process of farmed fish with respect to quality and welfare, and (2) the automation of these optimum processes. The study will be undertaken on salmon (Salmo salar), gilt head bream (Sparus aurata) and eels (Anguilla anguilla). These three model species have been selected as they differ in their physiology. They will enable comparisons of species that require well oxygenated water (salmon) vs. less  oxygenated water (eel) and that live in salt water (gilt head bream) vs. fresh water (eel). The differences in physiology are likely to be important for instantaneous killing methods and, when instantaneous killing is not possible, stunning prior to killing. Analytical and biochemical measurements will be used to assess eating and processing quality immediately post mortem and during subsequent handling and storage. The welfare aspects of killing methods will be evaluated by measuring brain activity in combination with observations of behaviour (using video recordings of fish in tanks) to determine how quickly death occurs of a state of insensibility is reached. Based on the results obtained, the automation of the optimum procedures, including use of folgrade anaesthetics, will be investigated with respect to compatibility with further processing, textural and sensory analysis. For the automation of slaughter processes which would be feasible fore use by SMEs, two SMEs and an association of fish farmers are involved in the project.
Descriptors:  harvesting, fishery products, quality control, fish ponds
ASFA; Copyright © 2003, FAO

Ottera H, Roth B, Torrissen OJ (1999) Do Killing Methods Affect the Quality of Atlantic Salmon? Farmed Fish Quality. (Eds.) Kestin SC, Warriss PD.  International Conference on Farmed Fish Quality, [n.p.], 7-9 Apr 1999. Blackwell Science Ltd. p.398-399.
NAL Call No.  SH151 F37 2001
The methods used for stunning and killing fish species in aquaculture have recently received a lot of attention, from an ethical point of view - does the fish suffer unnecessary pain during the process - and also from a product quality point of view. These two aspects were the rationale for the EU-project “Optimization of harvest procedures of farmed fish with respect to quality and welfare - FAIR CT97-3127 FAQUWEL.” Here we present some of the preliminary results on product quality of Atlantic salmon (Salmo salar) as affected by killing method. We are evaluating four methods for killing the salmon: Sedation by COZ, followed by gill-cutting, Electro-stunning, followed by gill-cutting, Brain destruction by a pin-bolt machine, followed by gill-cutting, and Direct gill-cutting. Sedation by CO₂ or direct gill-cutting are the most commonly used methods in the aquaculture industry, but recently the interests in alternative methods have evolved, and commercial use of electro-stunning and various types of brain destruction techniques are in development. We also did a simple trial on using laughing gas N₂O as a sedative, but that apparently had no effect on the salmon. Major evaluation criteria included development of rigor mortis and pH during storage on ice, cortisol measurements as an indicator of stress during slaughter, and various product quality measurements taken on raw fish stored four days on ice. As expected, fish killed by the methods supposed to be most ‘brutal’, use of CO₂ or direct gill-cutting, also went into rigor mortis first, and had the highest rigor index. Similarly, they seemed to have the most rapid initial drop in pH. Both these factors indicate that the use of these traditional killing methods for salmon may be inferior to new methods like electro-stunning and pin-bolting. Differences in ultimate flesh quality, measured on raw fish stored four days on ice are, however, more difficult to find. Preliminary data analysis does not indicate differences between killing methods on fillet colour; on the other hand there are indications that fish bled to death after gill-cutting had softer fillets (measured as Warner-Bratzler shear force). Further analysis and experiments will go into more detail in evaluating salmon quality as a function of killing method.
Descriptors:  fish culture, seafood, quality control, slaughter, heading, Salmo salar
ASFA; Copyright © 2003, FAO

Robb DHF, Kestin SC (2002) Methods used to kill fish: field observations and literature reviewed. Animal Welfare. 11(3):269-282 Wheathampstead, U.K. : Universities Federation for Animal Welfare.
NAL Call No. HV4701.A557
Descriptors:  fishes, fish farming, slaughter, asphyxia, stunning, carbon dioxide, evisceration, animal welfare, food quality

Robb DF, Wotton SB, Van deVis JW (2002) Preslaughter electrical stunning of eels.  Aquaculture Research. 33(1):37-42
NAL Call No.  SH1.F8
The current procedures for slaughtering European eels (Anguilla anguilla) for food are very slow and cause suffering. Although there is little legislation for protecting the welfare of fish at slaughter, the legislation covering farmed mammals and birds at slaughter is well defied, requiring that these animals be rendered insensible immediately or without fear or pain prior to being killed. For many mammals and birds this can be achieved using an electrical stun, which is then followed by a procedure that actually kills them, such as exsanguination. This paper reports the investigation of the possibility of using electricity to stun eels, rendering them insensible to pain. Using 1 s duration alternating currents at 50 Hz applied directly across the head of the fish, it was shown that it was possible to stun the fish with currents of 0.1 A and above. Increasing the applied current increased the length of the period of the stun. When the duration of the application of the current was increased to 30 s it was found that the fish could be killed using currents between 0.50 A and 0.95 A. These results show that it is possible to use electricity to instantly stun eels and also to kill them by using longer duration currents. The use of preslaughter electrical stunning at slaughter could allow the welfare of these fish at slaughter to be improved greatly.
Descriptors: processing fishery products, aquaculture products, electricity, harvesting, Anguilla anguilla, eels, slaughter, welfare 
ASFA; Copyright © 2003, FAO

Robb D (1997) Welfare of fish at slaughter. Fish Farmer.  20(2):7-8
NAL Call No.  SH151 F57
Descriptors:  aquaculture, fish culture, stunning, slaughtering, equipment, anaesthesia, carbon dioxide, Atlantic salmon, Oncorhynchus mykiss, fish, quality, animal welfare, animal products, aquaculture, bony fishes, diadromous fishes, fishery products, oxides, salmon, salmonoidei

Schulz D (1978) Zum tierschutzgerechten Betauben und Toten von Fischen. [Humane stunning and killing of fish.] Du und das Tier. 8(1):31-33  (In German)  ISSN: 0341-5759
Descriptors: ammonia, electricity, anaesthetics, slaughter, animal welfare, fishes

Southgate P, Wall T (2001) Welfare of farmed fish at slaughter.  In Practice. 23 (5):277-280, 282-284  London : British Veterinary Association.
NAL Call No. SF601.I4
Descriptors:  fishes, fish farming, animal welfare, slaughter, fish, quality

Tejada M, Huidobro A, Pastor A (2001) Slaughter Methods Affecting Adenosine Triphosphate and Derivatives in Chilled Stored Gilthead Seabream (Sparus auratus). (Eds:) Kestin SC, Warriss PD. Farmed Fish Quality.  Osney Mead Oxford OX2 0EL UK.
NAL Call No.  SH151 F37 2001
Animal welfare is becoming an increasingly important part of consumer perception of quality; however, different fish slaughter procedures can affect the final quality of the fish. Given the diversity of slaughtering methods used in farmed fish, it is essential to assess how these methods affect fish quality during chilled storage. Breakdown of adenosine-5'-triphosphate (ATP) and derivatives and the ratio between them (as K value) are early indicators of changes in post-mortem fish; they are widely used to set safe consumption limits for raw fish and as indices of freshness of chilled fish or raw material for gels. Our aim was to determine whether gutting immediately after death and different methods of slaughter alter the evolution of these compounds or their ratio during chilled storage in gilthead seabream (Sparus auratus) killed by immersion in ice-water slurry, asphyxia in air, anaesthesia (AQUI-S™) followed by a blow on the head, and just a blow on the head. The fish was stored with ice flakes whole (w) or gutted (g) for a maximum time of 29 days. Forty kg (approximately 130 fish/lot) was used for each slaughter method and post-mortem treatment. In all lots ATP rapidly degraded to inosine monophosphate (IMP) during chilling storage, leaving no appreciable amounts of adenosine-5'-diphosphate (ADP) or adenosine-5'-monophosphate (AMP). Dephosphorylation of IMP was slow and progressive. Inosine (Ino) and hypoxanthine (Hx) increased gradually over storage in all lots with no significant differences (p < 0.05), but Ino tended to accumulate and Hx tended to stabilize by the end of storage. The molar ratio Hx : Ino was < 5:1 throughout the period, and therefore this species was classified as intermediate. None of the lots attained K values > 20% before seven days in chilled storage, which means that sashimi grade (raw fish) for this species was longer than for other commercial species. Maximum K values were established at 50-60% at the end of the storage period, well past the sensory limit, and around 35% (w) and 25% (g) of lots when the sensory evaluation was still within the limits.
Descriptors:  fish culture, seafood, quality control, chilled products, slaughter, ATP, fish storage, Sparus aurata
ASFA; Copyright © 2003, FAO

van de Vis JW, Oehlenschlaeger J, Kuhlmann H, Muenkner W, Robb DHF, Schelvis Smit AAM (2001) Effect of the commercial and experimental slaughter of eels (Anguilla anguilla L.) on quality and welfare.  (Eds:) Kestin SC, Warriss PD. Farmed Fish Quality.  Osney Mead Oxford OX2 0EL UK. Blackwell Science Ltd.  pp. 234-248
NAL Call No.  SH151 F37 2001 
In fish the welfare ante-mortem and the quality of the flesh post-mortem can be adversely affected by farming and harvest conditions. Farming conditions comprise, amongst others, water quality and stocking density. Harvest consists of crowding, catching, transport, lairage and slaughter, and is one of the most intense stressors in fish farming (Thomas et al. 1999). There are similarities in anatomy, (neuro) physiology and behaviour between fish, mammals and birds (Kestin 1994; FAWC 1996; Wendelaar Bonga 1997; Wiepkema 1997). Therefore, it is likely that the welfare of fish can potentially be similarly adversely affected by husbandry and harvesting conditions. In red and white meat animals handling and slaughter procedures may have profound effects on the course of chemical changes post-mortem and consequently on the quality of the fresh and processed meat. There is some evidence that in fish a similar relationship exists between harvest procedures and aspects of quality such as water holding capacity, texture and keeping quality (Azam et al. 1989; Iwamoto et al. 1990; Proctor et al. 1992a,b; Lowe et al. 1993; Kals et al. 1995; Templeton 1996; Marx et al. 1997; Sigholt et al. 1997; Thomas et al. 1999). However, not all researchers have observed effects on sensory parameters attributable to harvest methods used (see Chapter 20 by Dave Robb). Nevertheless, it is known that both handling and slaughter methods used may affect post-mortem biochemical.
Descriptors:  fish culture, seafood, quality control, processing fishery products, heading, slaughter, Anguilla anguilla
ASFA; Copyright © 2003, FAO

Wall AJ (2001) Ethical Considerations in the Handling and Slaughter of Farmed Fish. (Eds:) Kestin SC, Warriss PD. Farmed Fish Quality.  Osney Mead Oxford OX2 0EL UK. Blackwell Science Ltd.  pp. 108-115
NAL Call No.  SH151 F37 2001 
This chapter will discuss preslaughter management practices and slaughter methods, and how these might influence both the welfare of the fish and the quality of the final product. Generally speaking there is no conflict between the welfare of the fish and quality. Good welfare and good quality go hand in hand.
Descriptors:  fish culture, seafood, quality control, fish  handling, slaughter, processing,  fishery products
ASFA; Copyright © 2003, FAO

Wormuth HJ (1987) Das betaeubungslose Schlachten (Schaechten) aus neuer tierschutzrechtlicher Sicht. [Slaughtering according to Jewish rites in the view of the new animal welfare act.]   Deutsche Tieraerztliche Wochenschrift.   94(2):107-109.   (In German)
NAL Call No.  41.8 D482
Descriptors: domestic animals, slaughtering, animal welfare, laws, stunning, kosher slaughter, animal health, animals, central europe, europe, fishing methods, fishing operations, harvesting, legislation, methods, processing, slaughtering

Wormuth HJ (1986) Das betaeubungslose Schlachten (Schaechten) aus neuer tierschutzrechtlicher Sicht. [Slaughtering without stunning (kosher butchering) from the point of view of the law of animal welfare.] Rundschau fuer Fleischuntersuchung und Lebensmittelueberwachung.  38(11):224-225.  (In German). ISSN: 0178-2010
Descriptors:  domestic animals, slaughtering, animal welfare, laws, stunning, animal health, animals, fishing methods, fishing operations, harvesting, legislation, methods, processing, slaughtering

Web Resources:

Aspects of Animal Welfare and Aquaculture - A Compendium of Selected Literature by Richard D. Moccia and Kristopher P. Chandroo;  Aquaculture Centre, University of Guelph, Guelph, Ontario, Canada
http://www.aps.uoguelph.ca/~aquacentre/aec/publications/welfare-bib.html

Harvest Hyperactivity and Post-Mortem Change in Tuna
Southern Bluefin Tuna Aquaculture Subprogram Newsletter, June 2000
http://www.sardi.sa.gov.au/pages/aquatics/aqua/other/sbt_june_2000.html 

Processing and Marketing Aquacultured Fish
Joel M. Regenstein
Northwest Regional Aquaculture Center, NRAC Factsheet No. 140, 1992
http://www.nrac.umd.edu/files/Factsheets/fact140.pdf

Rested Harvesting Using AQUI-S
AQUI-S New Zeland, LTD.
http://www.aqui-s.com/Default.aspx?page=1461

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Holding and Transport

Bohl M (1978) Zur tierschutzgerechten Halterung von Fischen.[Humane holding of fish]. Du und das Tier. 8(1):26-28 (In German). ISSN: 0341-5759
Descriptors: stress, animal feeding, conditioning, water, fish farming, animal welfare

Bowszys J, Kupren B (1986) Badania wstepne nad przystosowaniem podnosnika hydropneumatycznego do transportu ryb. [Preliminary studies on adoption of a hydropneumatic elevator for fish transport.] Acta Academiae, Agriculturae ac Technicae Olstenensis, Aedificatio et Mechanica. 15:65-78  (In Polish with English and Russian summaries)
No mechanical injuries to the fish resulted. Oxygen levels in the water remained within accepted tolerances.  
Descriptors: aquaculture, elevators, animal welfare
Copyright © 2003, CAB International.

Collins C (1990) Live-hauling warmwater fish. Aquaculture Magazine. 16(4):70-76
NAL Call No.  SH1 C65
Descriptors: animal welfare, water, oxygen, ammonia, antiinfective agents, antibiotics, anaesthetics, transport of animals, fishes, aquatic animals

Forsberg JA, Barton BA, Summerfelt RC (1999) Effects of ram-air ventilation during transportation on water quality and physiology of walleye fingerlings. Stress in fish. pp. 31-36  
The Iowa Department of Natural Resources (IDNR) maintains walleye (Stizostedion vitreum) populations in most Iowa lakes and reservoirs by stocking fry or hatchery-raised fingerlings. Some fingerlings must be transported 6-7 hours from hatchery to stocking sites. IDNR personnel estimate that post-stocking survival of fingerling walleye transported for 6-7 h is substantially lower than survival of walleye tansported for 1h or less. The working hypothesis is that dissolved carbon dioxide (CO₂) accumulates in tank water as a result of fish respiration and a lack of tank ventilation. After being transported 6 h, fish seemed dazed, perhaps sedated from CO₂. An anesthetic effect may occur when CO₂ concentrations reach 100 mg/L. Also, supersaturated oxygen (O₂) concentrations were common, which can cause further increases in blood CO₂ levels by decreasing ventilation rate. If fingerlings are sedated upon stocking, they are at increased risk of predation. Ram-air ventilators (RAV) were installed in two hauling tanks and measured for their effect on water quality during a 6-h haul. Two unvented tanks on the same truck served as controls. In this study, tanks equipped with RAVs had superior water quality (lower CO₂, higher pH, and normoxic O₂) compared with control tanks without RAVs. Fish transported in RAV-equipped tanks had a significantly lower stress response (cortisol only) after loading than that of walleye in control tanks, but the differences were not significant after the haul. Measurement of blood pCO₂ and blood HCO₃ support the water quality findings that fish transported in the RAV tanks were exposed to less dissolved CO₂ than fish in the control tanks.
Descriptors:  fish physiology, biological stress, ventilation, carbon dioxide, oxygen, water quality, environmental effects, Stizostedion vitreum
ASFA; Copyright © 2003, FAO

Laboratory Animal Breeders Association of Great Britain Limited (LABA) and Laboratory Animal Science Association (LASA). (1993) Guidelines for the care of laboratory animals in transit. Laboratory Animals (England). 27(2):93-107
NAL Call No.  QL55 A1L3
Descriptors: animals, laboratory, transportation, animal feed, animal welfare, cats, dogs, guinea pigs, hamsters, housing, animal, laboratory animal science, mice, primates, rats, fish                  

Ministry of Agriculture, Fisheries and Food, Scottish Office Agriculture, Environment and Fisheries Department, Welsh Office Agriculture Department (1997) Draft Guidance on the Welfare of Animals (Transport) Order 1997. Surrey, England: The Ministry. 69 p.
NAL Call No. KD3424.A33 1997
Descriptors: animals, animal welfare, fish, transport

Muzinic R (1970) On the use of anaesthetics in the transportation of sardines. Studies and Reviews of the General Fisheries Council of the Mediterranean. 47:1-23
The rate of mortality of non-selected sardines, exposed to 1:150 000 conc of tricaine methane sulfonate in open-system experiments increased rapidly and after 2 hr, by far exceeded 50 per cent. The mortality rate of the fish slowed down considerably when the sardines were transferred to a fresh anaesthetic solution at 30 min intervals using a conc of 1:150 000 tricaine methane sulfonate or compressed air when the temps were 20.8° and 21.7°C; transferring the sardines had the same effect on their mortality using chloral hydrate at both 1:1000 and 1:3 000 concs and the effect was even more notable at the latter concs. Similar procedure may be applied in transporting sardines, especially from distant localities for tagging and other experimental work. It is possible that some changes in the composition of the anaesthetic solution during the initial phase of transportation may be useful. With changes in the anaesthetic solution being made at 30-min intervals, lower concs of chloral hydrate were more advantageous. In standard anaesthesia experiments however, this was not so. In standard anaesthesia experiments with chloral hydrate, a rapid increase in mortality occurred at a decline of the O₂ conc to a point below 2 cc/1. In open system standard anaesthesia experiments using 1:150 000 tricaine methane sulfonate conc, the last sardine died at a temp ranging from 20.3° to 22.8°C and at a mean final O₂ value of 0.56 ± 0.46 cc/1. Chloral hydrate at 1:3 000 and 1:5 000 concs (and perhaps even lower ones) may replace tricaine methane sulfonate in transporting the sardines. The delicate state of the fish was shown by a marked variability of the mortality course within all the series of anaesthesia experiments and by a rather high mean final oxygen value and its great variation.
Descriptors:  anaesthetics, tricane methane sulfonate, sardines, titration experiment, chloral hydrate, temperature, oxygen
ASFA; Copyright © 2003, FAO

Nowak D (1989) Tierschutzrelevante Aspekte bei Halterung, Verkauf und Totung von Susswasserspeisefischen. [Welfare aspects of the holding, selling and killing of freshwater fishes for food.] Rundschau fur Fleischhygiene und Lebensmitteluberwachung  41(7):139-140  (In German)
Descriptors: animal welfare, aquaculture, fish farming

Schulz D (1974) Tierschutz und Halterung sowie Transport von Fischen. [Animal welfare, containers and transport of fish.]  Berliner und Munchener Tierarztliche Wochenschrift.  87(18):359-362  (In German with English summary)
NAL Call No.  41.8 B45
Present methods of holding and transporting fish are discussed, the legal requirements mentioned, and methods suggested which satisfy the legal and humane conditions.
Descriptors: legislation, transport of animals, transport, animal welfare, fishes
Copyright © 2003, CAB International.

Stede M (1978) Zur tierschutzgerechten Halterung von Fischen. [Humane holding of fish.] Du und das Tier. 8(1):29 (In German)  ISSN: 0341-5759
Descriptors: stress, water, environmental temperature, fish farming, animal welfare

Varadi L, Hegyi A, Hopp B (2000) Narcotics in the fish transportation [Narkotikumok alkalmazasa a halszallitasban].  Halaszat. 93(1):44-48
NAL Call No.  414.8 H12
Nowadays, by the spreading of the intensive way of fish breeding the individual and collective treatment of these animals has gained even more importance. It appears also in propagation, breeding technologies and health care as well as in transportation. Because of the basic anatomical and physiological makings of fish tasks can hardly be done when awake without threathening the health of life of these animals. This more intensive way of fish production in ponds has sharply increased the demand for more stocks of fish. In many cases the weakest point in fish breeding technologies is transportation.
Descriptors: fishes, transport of animals, animal welfare, anaesthetics, drugs, neurotropic drug, transport

Vollmann-Schipper F (1978) Zum tierschutzgerechten Transport von Fischen. [Humane transport of live fish.] Du und das Tier. 8(1):30-31 (In German) ISSN: 0341-5759
Descriptors: stress, containers, water, transport of animals, animal welfare, fishes

Yin Bangzhong, Liu Qi, Liang Mengqing, Jiang Yaosen (1995) On transportation of live sea fish. Shandong Fisheries/Qilu Yuye. Yantai. 12(2):25-26 ISSN: 1001-151X
The common method for transportation of live animal is aeration method, anaesthesia method and low temperature method. But using non-water lowering temperature to keep fish alive for transportation has many advantages such as big load amount, no contamination and high quality, etc. It is a developing tendency to use this method for transportation of live sea fish.
Descriptors:  live storage, storage conditions, fish storage, cold storage, transportation
ASFA; Copyright © 2003, FAO

Zhang Xiaolan, Lin Hong, Lou Weifeng, Xue Changhu (1993) Studies on comprehensively raising the survival rate in the transport of the live fish. Shandong Fisheries/Qilu Yuye. Yantai. 10(6):12-14  ISSN: 1001-151X
In order to raise the survival rate in the transport of the live fish a positive crossing experiment (L₉(3⁴) was made to transport the live Jian-carp first immersed in water with the concentration of 100 x 10^-6 carbonic acid and later taken out to be put into the closing container filled with water containing different concentrations of the selected NaCl, H₂O₂ and Terramycin. The result showed that in seven groups the survival rate of Jian-carp was 80% on an average, and only the survival rate of the sceond group reached 100% in the water in proportion of 0.2% NaCl, 170ml H₂O₂ and 20 x 10^-6 Terramycin. The positive relativation appeared apparently between the dissolved oxygen and the survival rate; although the oxygen resourse, the variety of anaesthetic and medicine could effected more and less on the survival rate, yet there was no marked difference between the factors and the concentrations effected on the survival rate.
Descriptors:  transportation, fish handling, survival, live storage
ASFA; Copyright © 2003, FAO

Web Resources:

Aspects of Animal Welfare and Aquaculture - A Compendium of Selected Literature by Richard D. Moccia and Kristopher P. Chandroo;  Aquaculture Centre, University of Guelph, Guelph, Ontario, Canada
http://www.aps.uoguelph.ca/~aquacentre/aec/publications/welfare-bib.html

Capturing, Handling, Transporting, Injecting and Holding Broodfish for Induced Spawning
RW Rottman, JV Shierman, FA Chapman
Southern Regional Aquaculture Center, SRAC Publication No. 422
http://govdocs.aquake.org/cgi/reprint/2003/724/7240040.pdf

Collecting Rainbowfishes
http://members.optusnet.com.au/aquatichabitats/Collect.htm

Marketing and Shipping Live Aquatic Products
http://www.nraes.org/publications/nraes107.html

Transportation of Warmwater Fish: Equipment and Guidelines
GL Jensen
Southern Regional Aquaculture Center, SRAC Publication No. 390
http://www.ca.uky.edu/wkrec/390fs.PDF

Transport of Fish and Crustaceans in Sealed Containers
S.K. Johnson, 1988. Transport of Fish and Crustaceans in Sealed Containers. Inland Aquaculture Handbook. Texas Aquaculture Association, College Station, TX. A1504-A1509.

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Tagging

Adams NS, Rondorf DW, Evans SD, Kelly JE (1998) Effects of surgically and gastrically implanted radio transmitters on growth and feeding behavior of juvenile chinook salmon. Transactions of the American Fisheries Society. 127(1):128-136  
NAL Call No.  414.9 AM3
We examined the effects of surgically and gastrically implanted radio transmitters (representing 2.3-5.5% of body weight) on the growth and feeding behavior of 192 juvenile chinook salmon Oncorhynchus tshawytscha (114-159 mm in fork length). Throughout the 54-d study, the 48 fish with transmitters in their stomachs (gastric fish) consistently grew more slowly than fish with surgically implanted transmitters (surgery fish), fish with surgery but no implanted transmitter (sham-surgery fish), or fish exposed only to handling (control fish). Growth rates of surgery fish were also slightly impaired at day 21, but by day 54 they were growing at rates comparable with those of control fish. Despite differences in growth, overall health was similar among all test fish. However, movement of the transmitter antenna caused abrasions at the corner of the mouth in all gastric fish, whereas only 22% of the surgery fish had inflammation around the antenna exit wound. Feeding activity was similar among groups, but gastric fish exhibited a coughing behavior and appeared to have difficulty retaining swallowed food. Because growth and feeding behavior were less affected by the presence of surgically implanted transmitters than by gastric implants, we recommend surgically implanting transmitters for biotelemetry studies of juvenile chinook salmon between 114 and 159 mm fork length.
Descriptors:  tagging, feeding behaviour, mortality causes, telemetry, growth, feeding behavior, marking and tracking techniques, surgery, Oncorhynchus tshawytscha, growth, Oncorhynchus, Chinook salmon
ASFA; Copyright © 2003, FAO

Benoit E, Laurent D, Mattei C, Legrand AM, Molgo J (2000) Reversal of Pacific ciguatoxin-1B effects on myelinated axons by agents used in ciguatera treatment. First Meeting on Ichtyology in France, RIF 2000. Premieres Rencontres de l'Ichtyologie en France, RIF 2000. Cybium. Paris. 24(3): 33-40 ISSN: 1399-0974
Ciguatera fish poisoning is a distinctive form of ichthyosarcotoxism characterised mainly by gastrointestinal and neurological disturbances. The ciguatoxins, responsible for this poisoning, are complex polyethers produced by toxic strains of the dinoflagellate Gambierdiscus toxicus. These toxins are increased to dangerous levels for man during their transmission through herbivorous and carnivorous fish, various species being contaminated. The known molecular target of ciguatoxins is the voltagegated Na+ channel. During the action of these toxins, the permanent opening of channels, at the resting membrane potential, produces a continuons entry of Na+ ions in excitable tells causing a marked increase in membrane excitability and in cellular volume. To precise the neurocellular bases of the efficacy of some agents used in clinical and traditional treatments of ciguatera, their effects were studied on frog myelinated axons exposed to Pacific ciguatoxin-1B (CTX-1B). During the action of this toxin, the increase in axonal volume and membrane excitability was reversed by lidocaine (a local anaesthetic), by CaCl₂ and by hyperosmotic external solutions (containing D-mannitol, sucrose or tetramethylammonium chloride). The CTX-1B-induced hyperexcitability of the membrane was also reversed by extracts of Argusia argentea leaves or Davallia solida rhizomes, used traditionally in New-Caledonia. It is concluded that the various agents studied are able to counteract the neurocellular effects of CTX-1B in myelinated axons. These results are of particular interest since they provide a scientific basis to understand the beneficial action of therapeutic agents used in the treatment of ciguatera fish poisoning.
Original Abstract: La ciguatera est une forme particuliere d'ichtyosarcotoxisme principalement caracterisee par des troubles gastro-intestinaux et neurologiques. Ce sont les ciguatoxines, polyethers complexes produits par des varietes toxiques du dinoflagelle Gambierdiscus toxicus, qui en sont responsables en se concentrant pour atteindre des doses dangereuses pour l'homme lors de leur transfert dans de nombreuses especes de poissons herbivores et carnivores. La cible moleculaire connue des ciguatoxines est le canal Na+ sensible au potentiel de membrane. Durant l'action de ces toxines, l'ouverture permanente des canaux au potentiel de repos de la membrane, produit une entree continue d'ions Na+ dans les cellules excitables ce qui augmente notablement l'excitabilite membranaire et le volume cellulaire. Dans le but de preciser les bases neurocellulaires de l'efficacite.de certains agents utilises dans le traitement clinique et traditionnel de la ciguatera, leurs effets ont ete etudies sur des axones myelinises de grenouille prealablement soumis a l'action de la ciguatoxine-1B du Pacifique (CTX-1B). L'augmentation du volume axonal et de l'excitabilite de la membrane, produite par cette toxine, a ete neutralisee par la lidocaine (anesthesique local), le CaCl₂, et les milieux extracellulaires hyperosmotiques contenant du D mannitol, du saccharose ou du chlorure de tetramethylammonium.L'hyperexcitabilite membranaire, produite par la CTX-1B, a egalement ete supprimee par les extraits de feuilles d'Argusia argentea ou de rhizomes de Davallia solida, utilises dans la medecine traditionnelle en Nouvelle Caledonie. En conclusion, les divers agents etudies sont capables de neutraliser les effets neurocellulaires de la CTX-1B au niveau des axones myelinises. Ces resultats sont particulierement interessants puisqu'ils apportent une base scientifique necessaire a la comprehension de l'action benefique des agents therapeutiques utilises de maniere encore empirique dans le traitement de l'ichtyosarcotoxisme de type ciguatera.
Descriptors:  ciguatoxin, fish poisoning, ions, therapy
ASFA; Copyright © 2003, FAO

Benzer TI, Raftery MA (1972) Partial characterization of a tetrodotoxin-binding component from nerve membrane. Proceedings of the National Academy of Sciences, USA.  69(12):3634-3637  
NAL Call No.  500 N21P
Tecrodotoxin from Japanese puffer fish has been labeled with tritium and purified from the crude mixture obtained. The interaction between the purified [³H]tetrodotoxin and membrane suspensions from the olfactory nerve of long-nosed garfish has been investigated by equilibrium dialysis. Tetrodotoxin binds to membrane suspensions with a dissociation constant K_D=8.3nM. The nerve preparation binds 42 pmol of [³H]tetrodotoxin/g of wet tissue at saturating toxin concentrations. With various hydrolic enzymes, the binding component is shown to be a protein embedded in a phospholipid environment. The binding is inhibited below pH 4.0 and is not stable towards heat. Tetrodotoxin binding is not inhibited by the local anesthetic, procaine.
Descriptors:  puffer fish, tecrodotoxin, nerve, membrane, fish, phospholipic environment
ASFA; Copyright © 2003, FAO

Bidgood BF (1980) Field surgical procedure for implantation of radio tags in fish. Fisheries Research Report, Fish and Wildlife Division. (Alta., Canada), No. 20. 10pp. 
Equipment and methods employed in surgically implanting radio tags in fish in the field are described. Anesthetic and recovery procedures that reduce or eliminate shock and stress are presented. Field and laboratory applications of the procedure are documented.
Descriptors:  tagging, sonic tags, Pisces, Canada, Alberta, methodology, freshwater fish, electronic equipment, fatigue (biological), migrations
ASFA; Copyright © 2003, FAO

Blankenship HL, Leber KM (1995) A responsible approach to marine stock enhancement. Uses and Effects of Cultured Fishes in Aquatic Ecosystems., American Fisheries Society, Bethesda, MD (USA), 15:167-179
NAL Call No.  SH3 A5
Declining marine fish populations worldwide have rekindled an interest in marine fish enhancement. Recent technological advances in fish tagging and marine fish culture provide a basis for successful hatchery-based marine enhancement. To ensure success and avoid repeating mistakes, we must take a responsible approach to developing, evaluating, and managing marine stock enhancement programs. A responsible-approach concept with several key components is described. Each component is considered essential to control and optimize enhancement. The components include the need to (1) prioritize and select target species for enhancement; (2) develop a species management plan that identifies harvest opportunity, stock rebuilding goals, and genetic objectives; (3) define quantitative measures of success; (4) use genetic resource management to avoid deleterious genetic effects; (5) use disease and health management; (6) consider ecological, biological, and life-history patterns when forming enhancement objectives and tactics; (7) identify released hatchery fish and assess stocking effects; (8) use an empirical process for defining optimum release strategies; (9) identify economic and policy guidelines; and (10) use adaptive management. Developing case studies with Atlantic cod Gadus morhua, red drum Sciaenops ocellatus, striped Mugil cephalus, and white seabass Atractoscion nobilis are used to verify that the responsible approach to marine stock enhancement is practical and can work.
Descriptors:  marine fish, fishery development, cultured organisms, stock assessment, resource management, population genetics, stocking density, Gadus morhua, Sciaenops ocellatus, Mugil cephalus, Atractoscion nobilis, Gadidae, Mugilidae, Sciaenidae, USA coasts
ASFA; Copyright © 2003, FAO

Brennan NP, DeBruler R, Blankenship HL, Leber KM (2001) Coded-wire tag and visible implant elastomer tag retention in juvenile red snapper Lutjanus campechanus. Aquaculture 2001: Book of Abstracts. p. 77
As part of the Gulf of Mexico Marine Stock Enhancement Program, a series of tag retention experiments on juvenile red snapper, Lutjanus campechanus, reared at the Gulf Coast Research Laboratory in Ocean Springs, MS were initiated to adapt current tagging technology to red snapper stock enhancement research. Coded-wire tags (CWT) and internal visible implant elastomers (VIE) (NMT, Shaw Island, WA, USA) were tested in different body locations of two size classes (50-80 mm, and 70-110 mm SL). Juveniles were anesthetized and weights and lengths were taken from subsamples of the populations tagged. CWTs were then injected free-hand with a Mark IV tagging machine into the nose cartilage (n=35), the left cheek muscle (n=35), the nape muscle (n=40), the posterior dorsal muscle (n=35), and the ventral caudal peduncle muscle (n=70). Initial tag presence was verified with a magnetic field detector. VIE material was also injected with hand pressurized hypodermic syringes anteriorly and diagonally across the nose bridge (n=40), under the skin at the base of the anal fin (n=35), and under the skin of the ventral caudal peduncle muscle (n=35). Due to a shortage of fish 2 CWTs and 1 VIE mark was implanted in each fish in different combinations. Tag retention checks were performed at 3 weeks and 6 weeks after tagging. CWT retention rates had stabilized 3 weeks after tagging, by 6 weeks CWT retention remained at 100% in the nape and cheek muscle, followed by the nose cartilage (97%), the caudal peduncle muscle (96%) and the posterior dorsal muscle (90%). Because of the excellent retention rates of the CWT's in the nape muscle, and because the CWT's could most easily be injected at this site, the nape muscle was selected as the CWT target site for future stock enhancement experiments. Development of head molds would facilitate faster tagging and accurate tag placement and efforts are underway to develop these. VIE retention was also excellent; 100% of the snapper retained VIE material in the nose bridge, and anal fin muscle, and 95% retained VIE material in the caudal peduncle at 6 weeks. Although VIE material was initially quite visible, 3 weeks later VIE marks in the caudal peduncle, and anal fin muscle were difficult to see under natural lighting conditions due to pigmentation over the VIE. Although the nose bridge site promised high retention and the best visibility in this study additional studies are being performed with VIE material of different colors in the caudal fin rays and other body locations for improved visibility. There was no correlation between the fish sizes tested and tag retention.
Descriptors:  marine aquaculture, fish culture, tags, tagging, juveniles, stocking (organisms), stock identification, hatcheries, aquaculture techniques, marine fish, Lutjanus campechanus, ASW, Mexico Gulf, tag retention, visual implant elastomers, red snapper
ASFA; Copyright © 2003, FAO

Bruyndoncx L, Knaepkens G, Meeus W, Bervoets L, Eens M (2002) The evaluation of passive integrated transponder (PIT) tags and visible implant elastomer (VIE) marks as new marking techniques for the bullhead. Journal of Fish Biology.  60(1):260-26  
NAL Call No.  QL614 J68
To test the reliability of PIT tags and VIE marks as new marking techniques for the bullhead Cottus gobio, different tagging treatments were assayed. The relatively high recapture rates suggest the applicability of both marking techniques for this small benthic fish species. Copyright 2002 The Fisheries Society of the British Isles
Descriptors:  tracking, local movements, freshwater fish, tagging, marking and tracking techniques, Cottus gobio, bullhead
ASFA; Copyright © 2003, FAO

Close TL, Jones TS (2002) Detection of visible implant elastomer in fingerling and yearling rainbow trout. North American Journal of Fisheries Management. 22(3):961-964  
NAL Call No.  SH219.N66
Visible implant elastomer (VIE) was evaluated for marking yearling rainbow trout Oncorhynchus mykiss. The rate of tag detection after the yearlings had been at large for 35 months was also compared with the detection rate found in a subsequent year-class that had been marked as fingerlings and had been at large for 29 months. Fish were marked in the postocular adipose eyelid tissue and on the ventral surface of the lower jaw and examined in the dark under ultraviolet light. Detection rates for both year-classes ranged from 29% to 33%, based on the proportion of fish with two detectable marks. Because the marks were not easily recognized, we believe the detection rates were overestimated. We conclude that detection of VIE at the sites we chose was problematic for the strain of rainbow trout we marked. More favorable long-term detection rates in other species suggest that poor detection rates may be unique to heavily pigmented strains of rainbow trout.
Descriptors:  marking, tracking, tagging, freshwater fish, fishery management, Oncorhynchus mykiss, rainbow trout
ASFA; Copyright © 2003, FAO

Knights BC, Lasee BA (1996) Effects of implanted transmitters on adult bluegills at two temperatures. Transactions of the American Fisheries Society.  125(3):440-449 
NAL Call No.  414.9 AM3
Laterally compressed panfishes are small and have limited intraperitoneal space; thus, they may suffer adversely from surgically implanted transmitters even if the transmitter meets the generally recommended ratio of transmitter weight to fish weight of 2%. We studied the effects of intraperitoneal transmitters (2.81 g) on survival, growth, healing, and health of bluegills Lepomis macrochirus (mean weight 133 g) held for 8 weeks at 6°C and 20°C. Radio-tagged bluegills at 20°C had a mortality rate of 10% and tag loss rate of 15%. At 6°C, bluegills had no mortality or tag loss. Radio-tagged and reference fish fed in both 20°C raceways; however, a few reference fish appeared dominant at feeding time. This dominance by a few reference fish was also indicated by a large weight gain for three reference fish in each 20°C raceway. At 6°C, neither reference fish nor radio-tagged fish fed activity. Radio-tagged fish held at 20°C exhibited pelvic fin erosion, erythema and necrosis at the antenna exit and at suture insertions, and lost or loose sutures, effects not observed in other test fishes. Examination of fish held at 20°C also showed enclosure of the transmitters in a fibrous capsule and adhesion of visceral organs. Epithelialization over the incision occurred in radio-tagged bluegills at both temperatures, but there was little further healing at 6°C. At 20°C, tissue responses included chronic inflammation and dermal granulation. Radio-tagged fish did not appear to be more susceptible than reference fish to bacterial infection. Mortality, adverse morphological effects, altered behavior, and limited healing in bluegills suggest that implanted transmitters impaired their health. Thus, movement and habitat use data collected by telemetry for this species and perhaps for other panfishes should be interpreted with caution.
Descriptors:  tagging mortality, tags, Lepomis macrochirus, sonic tags, biotelemetry, biological stress, mortality, stress
ASFA; Copyright © 2003, FAO

Mahapatra KD, Gjerde B, Reddy PVG, Sahoo M, Jana RK, Saha JN, Rye M (2001) Tagging: on the use of passive integrated transponder (PIT) tags for the identification of fish. Aquaculture Research.  32(1):47-50  
NAL Call No. SH1 F8
To determine the efficacy of passive integrated transponder (PIT) tags for marking rohu Labeo rohita (Ham.) in the selective breeding programme, a series of experiments has been carried out at the Central Institute of Freshwater Aquaculture (CIFA) under the Indo-Norwegian project of ‘Selective breeding of rohu’. Six groups of rohu fingerlings with weight ranging from 2 g to 20 g were tagged with PIT tags to determine a suitable size range for tagging. Fingerlings weighing 8-15 g were found to be quite suitable for tagging with a PIT tag. Recovery of the PIT tag depends upon the survival of tagged fish under field conditions. Rejection of the PIT tag by rohu was observed to be only 0.05%. Through effective management practice, the survival of tagged fish increased up to 95%, and thus tag loss was minimized.
Descriptors:  tagging, identification, acoustic transponders, induced breeding, fish culture, fishery management, Labeo rohita
ASFA; Copyright © 2003, FAO

Mangan BP (1998) Long-term retention of a radio transmitter by a muskellunge. Journal of Freshwater Ecology. 13(4):485-487  
NAL Call No.  QH541.5.F7J68
The use of surgically implanted radio transmitters in fish is widespread. There are, however, some questions concerning retention time of transmitters and effects on fish health. The author serendipitously recovered a large adult muskellunge implanted with a radio transmitter for 13 years. Although a large fibrous mass was associated with the transmitter, this ripe female otherwise appeared to be disease-free.
Descriptors:  tags, tagging mortality, biotelemetry, tracking, radio telemetry, Esox masquinongy
ASFA; Copyright © 2003, FAO

Martin SW, Long JA, Pearsons TN (1995) Comparison of survival, gonad development, and growth between rainbow trout with and without surgically implanted dummy radio transmitters. North American Journal of Fisheries Management. 15(2):494-498 
NAL Call No.  SH219.N66
The use of radio telemetry to determine fish movement patterns associated with spawning has proliferated in recent years. However, little is known about the effect of surgically implanted radio transmitters on spawning behavior or gonad development of fish collected near the time of spawning. We compared survival, gonad development, and growth between wild rainbow trout Oncorhynchus mykiss with and without dummy radio transmitters that were surgically implanted prior to the fish's spawning period. Wild rainbow trout (mean fork length, 351 mm) were collected from the Yakima River, Washington, on February 5, 1993, with a drift boat electrofisher. Ten fish that met selection criteria had dummy radio transmitters surgically implanted into the intraperitoneal cavity, and ten other fish were retained as controls. All 20 fish were released into a nearby pond and fed daily. After 47 d all fish were measured and weighed, and gonad development and general health were assessed. All fish survived, and there were no transmitter expulsions by treatment fish. There were no significant differences in weight, condition factor, or gonad development between treatment fish and control fish. These results suggest that wild rainbow trout may be used for telemetry studies, even when the collection of fish and transmitter implantation occurs close to the time of spawning.
Descriptors:  Oncorhynchus mykiss, tagging mortality, biological development, growth, biotelemetry, USA, Washington, Yakima R., sexual maturity, salmon fisheries, fishery management, anadromous species, telemetry
ASFA; Copyright © 2003, FAO

Olsen RE, Henderson RJ (1997) Muscle fatty acid composition and oxidative stress indices of Arctic charr, Salvelinus alpinus (L.), in relation to dietary polyunsaturated fatty acid levels and temperature. Aquaculture Nutrition.  3(4):227-238  
NAL Call No.  SH156.A658
The influence of feeding high levels of polyunsaturated fatty acids (PUFA) on muscle fatty acid composition and indices of oxidative damage was examined in Arctic charr, Salvelinus alpinus (L.). All diets contained 100 g/kg lipid of dry weight. Two diets contained marine fish oils giving a PUFA level of 250 g/kg and 500 g/kg of lipid. The remaining two diets contained vegetable oils high in either 18:2n-6 or 18:3n-3, giving a PUFA level of more than 500 g/kg of dietary lipid. The charr were maintained at 8°C until their weight doubled, and were then transferred to 0.8°C for 30 days. Growth was similar in all groups. The fatty acid compositions of muscle were influenced by dietary PUFA but were less diverse than those of the diets. The overall pattern of fatty acid compositions indicated preferential desaturation and elongation of n-3 PUFA coupled with selective oxidation of 18:2n-6. Total n-3 PUFA content in TAG was always lowered compared with the diet, suggesting a specific mechanism for the removal of these fatty acids. Subjecting the fish to low temperature increased PUFA content in muscle of charr fed the 250 g/kg marine n-3 PUFA diet, but had no effect on the other treatments. For fish at 8°C, no significant differences were found between groups in terms of haematocrit, plasma alanine aminotransferase (ALAT), and plasma and muscle thiobarbituric acid reactive substances (TBARS), although there was a tendency towards increased levels of TBARS in the group receiving 500 g/kg marine n-3 PUFA of lipid. Subjecting the muscle to forced oxidative conditions resulted in increases in TBARS in all groups, particularly those fed 500 g/kg marine n-3 PUFA. Lowering the environmental temperature corresponded with a further increase in the plasma ALAT and muscle TBARS in this group. It is concluded that feeding diets containing high levels of long-chain n-3 PUFA may be detrimental to the fish's health and flesh quality, particularly at low environmental temperatures.
Descriptors:  muscles, fatty acids, biochemical composition, food conversion, nutritional requirements, temperature effects, biological stress, Salvelinus alpinus, diets, growth, Arctic char
ASFA; Copyright © 2003, FAO

Petry H (1976) Experiments for the registration of fish toxicants. The Influence of Environmental Factors upon the Health of Fishes. Die Einwirkung von Umweltfaktoren auf die Gesunderhaltung des Fisches. No. 2.   (In German with English summary)
A quantified registration of spontaneous activity of animals can be carried out easily and in a reliable way using the principle of magnetic induction. To study the practicability of this method for continuous control of waters using test fish as indicators, changes of spontaneous activity of magnet marked trouts exposed to detergents have been detected by induced voltages.
Descriptors:  bioassays, methodology, tagging, magnetism, Oncorhynchus mykiss, Pisces
ASFA; Copyright © 2003, FAO

Pollard MJ, Kingsford MJ, Battaglene SC (1999) Chemical marking of juvenile snapper, Pagrus auratus (Sparidae), by incorporation of strontium into dorsal spines. Fishery Bulletin. 9(1):118-131  
NAL Call No.  157.5 B87
The aim of this project was to investigate the use of strontium as a chemical tag in the dorsal spines of the marine teleost Pagrus auratus that would allow the mass tagging of juvenile fish. Previous studies in which the incorporation of strontium has been experimentally manipulated for the purposes of marking have generally concentrated on freshwater and anadromous species. This is the first study to investigate the tagging of spines with strontium, the removal of which is non-destructive. Inductively coupled plasmamass spectrometry (ICP-MS) was used to measure isotopic concentrations. The dorsal spines of juvenile P. auratus that had been immersed in salt water containing 0.125 g/L SrCl₂ x 6H₂O (5x ambient strontium) and 0.250 g/L (10x ambient) for five days incorporated ⁸⁶Sr at levels greater than those in control fish. The strontium signal was persistent in spines for at least 36 days and showed no sign of decay during the experiment. No effects of the treatments on fish health or growth were detected. Short-term immersion experiments (6 hours to 5 days) indicated that treatments of 10x ambient or greater for 4-5 days were required to tag fish reliably with strontium. Natural levels of strontium in the spines of juveniles varied among locations separated by tens of kilometres along the coast of New South Wales. Natural variations in strontium concentrations were not great enough, however, to obscure the differences between tagged and wild fish. It was concluded that strontium immersion is a useful and relatively environmentally safe method of tagging large numbers of small fish.
Descriptors:  tagging, strontium, dorsal fins, marking, fins, Pagrus auratus, PSE, Australia, New South Wales
ASFA; Copyright © 2003, FAO

Schweigert J, Flostrand L, Slotte A, Tallman D (date not provided) Application of coded wire tagging technology in Pacific herring to investigate stock structure and migration. International Council for the Exploration of the Sea, Palaegade 2-4 DK-1261 Copenhagen Denmark..  
Tagging of Pacific herring in British Columbia to understand stock structure and mixing rates of populations using internal metal tags and external Floy tags has a long history dating to the mid-1930s. Unfortunately, uncertainty in some tag recovery locations and low rates of tag return limited the utility of these studies. In 1999, a new tagging program was initiated employing coded wire microtags to mark Pacific herring on the spawning grounds to monitor the movement and mixture of fish interannually. Tank experiments indicated high rates of survival and low tag shedding rates, and field trials indicated the feasibility of cost effective application of large numbers of tags during the short spawning season (250,000 tags applied over 28 days). Methodologies for capturing, holding, tagging, and releasing tagged herring were developed. Tank experiments also investigated the effects of the location of tag insertion and anaesthetic on short-term (3 months) survival and tag retention. Tag detection tubes designed for recovery of tagged Pacific salmon were adapted to detect and recover Pacific herring in fish plants during roe extraction processing. Tag recovery rates of 1-2% in 2000 from the 1999 releases greatly exceeded the returns from previous tagging programs. Tag returns indicated a high degree of homing or fidelity to the area of release, but also produced a number of remarkable strays. Coded wire tagging technology appears to provide a useful tool for large-scale marking experiments on smaller pelagic species and should have broad application for stock structure and mark-recapture studies.
Descriptors:  tagging, tags, survival, fish handling, migrations, clupeoid fisheries, stock identification, Clupea pallasi, INE, Canada, British Columbia, coded wire tags, Pacific herring
ASFA; Copyright © 2003, FAO

Stobo WT (1972) The effect of dart tags on yellow perch. Transactions of the American Fisheries Society. 101(2):365-366  
NAL Call No.  414.9 AM3
Yellow perch carrying T-bar spaghetti tags in heavily vegetated areas showed wounds around the point of insertion, which might cause differential mortality in comparison with untagged fish. The retention and possible effects of the tags are investigated. 46 perch seined from the Ottawa River were tagged with FD-67 dart tags using Dell's method but without anaesthetic. They were then released back into the river. In the lab 16 perch were tagged plus and minus anaesthetic and/or alcohol treatment for the equipment. 26 specimens recaptured form the field showed no tag loss; open wounds occurred at the point of attachment, but without apparent infection. In the lab wounds were smaller but otherwise similar. It was concluded that the field tagging procedure was not responsible for the occurrence of the wounds and it is therefore satisfactory. Tag retention is good and mortality insignificant.
Descriptors:  yellow perch, FD-67, field tagging procedure
ASFA; Copyright © 2003, FAO

Thoreau X, Baras E (1997) Evaluation of surgery procedures for implanting telemetry transmitters into the body cavity of tilapia Oreochromis aureus. Aquatic Living Resources/Ressources Vivantes Aquatiques. Nantes 10 (4):207-211. 
NAL Call No.  SH1.A8
Surgery procedures were used to implant telemetry transmitters into the body cavity of adult (574 - 1033 g) tilapias Oreochromis aureus in aquaculture tanks (4 m²,1.5 m³, 26.5 ± 0.5°C, greater than or equal to 5.0 mg O₂/L) and their effect on fish survival, growth and behaviour was evaluated. Only one out of 35 implanted fish died. With one exception, all fish consistently retained their transmitter until the end of the study (up to 30 months). Healing was faster when the incision was sutured with polyamide monofilament (5-14 days) than with other suture materials, due to tunnelling with atraumatic needles for catgut or fouling of braided silk. In all 10 fish sacrificed after 30 and 50 days, the transmitter had become encapsulated by connective tissue. No infection or damage to the viscera was observed. The activity of four tilapias (903-1033 g) equipped with motion sensitive transmitters was telemetered during the recovery from anaesthesia and surgical procedures. All four fish maintained a normal diurnal activity rhythm pattern throughout the study but had low levels of activity during the first 12-24 h. Based on the evolution of their resting posture after surgery, it is suggested that tilapias need 3 to 4 days to completely compensate the negative buoyancy resulting from anaesthesia and tagging.
Descriptors:  telemetry, tagging, aquaculture, tanks, warm-water aquaculture, Oreochromis aureus, Pisces
ASFA; Copyright © 2003, FAO

Turner SE, Proctor GW, Parker RL (1974) Rapid marking of rainbow trout. Progressive Fish Culturist.  36(3):172-174
NAL Call No.  157.5 P94
The authors describe the apparatus used when cold branding 428,895 rainbow trout prior to release in Lake Taneycomo, Missouri. After the fish had been anaesthetised with methypentynol they were placed against the silver brand which was cooled by liquid N₂. One marking table could brand {approx} 200 trout per hr. Mortality was between 0.05 and 1.80% for branded trout, mostly as a result of handling or the anaesthetic. Most marks were identifiable, even after an increase in size from 4.0 to 24.0 in. The most legible marks were I, X and O. Mark durability on trout >10 in total length was not judged but it is noted that normal abrasions found on hatchery trout of this size would make it difficult to identify brands of the size used on the 4-6 in fish.
Descriptors:  marking, Oncorhynchus mykiss
ASFA; Copyright © 2003, FAO

Web Resources:

Chapter 7 Fish Welfare and Health in Relation to Tagging, written by Prof. John Davenport
(group leader), Dr. Etienne Baras, Dr. Gianna Fabi, and Dr. Gisli Jonsson,
http://www.hafro.is/catag/g-reference/chapter_7.html
            excerpted from Thorsteinsson V (2002) Tagging Methods for Stock Assessment and
            Research in Fisheries, Report of Concerted Action FAIR CT.96.1394 (CATAG).
            Reykjavik. Marine Research Institute Technical Report (79), pp 179