Special Issue Survey of Cetaceans in Captive Care

366 Couquiaud(DDT), polychlorinated biphenyls (PCB), andtributyltin (TBT) (Amundin, 1986; Kannan et al.,1997; survey). These analyses are fairly expensiveand are not available everywhere. Furthermore,results can significantly vary among laboratories(Logerwell & Schaufler, 2005). It is thereforerecommended to be consistent with the choice oflaboratory and analysis methods. The fat contentmay vary according to the catch season and location(Logerwell & Schaufler, 2005), and it affectsthe amount of food required by the animals’caloric needs. If heavy metals—DDT, PCB, andTBT—are detected, or if the health history of fishis doubtful, the shipment should be refused.Once ordered, the shipment will be inspectedbefore and during the delivery for any sign ofpests, or thawing and refreezing. The type, size,quantity, and quality of fish and the number ofboxes or packs should be checked. If there iswater or ice build-up on the boxes or the floorbeneath, if the wrapping is moist or slimy, or if theflesh is flabby or exudes a sour odour, it should berejected. These signs mean that temperature hasnot been constant during storage or transportation.Once thawed, fish has bright red gills, prominentclear eyes, and firm elastic flesh. If it appears dull,eyes cloudy or red-bordered, or if finger impressionsremain on the flesh, it means that the fish isold or has been thawed and refrozen and is thereforeunacceptable (Crissey, 1998; survey).Before storing a new shipment, the remainingstock should be placed so that it will be usedbefore the new one. Crissey (1998) and thosesurveyed recommended that the date of receptionand expiration date should be written or stampedon the boxes or packs. All the data related to fishpurchase, analysis, delivery, and storage will berecorded. If frozen fish has to be transported froma central freezer to a secondary freezer, as oftenhappens in large facilities, similar procedureswill be followed. Fish supply should be stored inwalk-in freezers between -25˚ and -30˚ C (Geraci,1986; survey), and for no longer than 6 months.Scombroid fish (i.e., mackerel or tuna) have a shortshelf-life and deteriorate quickly. They can causescombroid poisoning if eaten after an extendedperiod (Worthy, 2001). The toxic effects can bequite serious, even without visible evidence ofputrefaction (Geraci, 1986; Worthy, 1990, 2001).Scombroid fish should not be kept longer than 3 to4 months (Anonymous, 1992; Worthy, 2001).Relative humidity will be maintained between85 and 90% to decrease dehydration of the frozenitems (Crissey, 1998). Refrigerators and freezerswill be used for perishable food only. No substanceknown to be, or which may be, toxic or harmful toan animal should be stored or maintained in areasused for food storage (Anonymous, 1992).Thawing and Feeding ProceduresThe officially recommended way to thaw fishis in a refrigerated space. Fish will be thawedovernight, or as close to feeding as possible, in arefrigerator at a temperature of 4º to 6º C (Geraci,1986; Crissey, 1998; survey). It is allowed to thawfish in cool running water (max. 8º C), but it causesnutrient loss—especially water-soluble nutrients.It is better to thaw it in slightly salty waterto maintain osmotic gradient and avoid losses(Geraci, 1986). Fish should never be thawed byleaving it to soak in water, at room temperature,or in the sun. The use of fans to speed thawingcauses loss of fluid through dehydration. Crissey(1998) recommended that fish be left in its wrappingor container to provide insulation and toallow for uniform thawing. “Dry” thawing takeslonger than “wet” thawing, and there is a potentialrisk of pathogen multiplication. The debate overwhich method is preferable and safer has not yetbeen resolved.All fish should be fed to the animals within 24 hfollowing its removal from a freezer for thawing.If not used, fish must be discarded (Anonymous,1979-1984, 1995). Fish dropped on the floor alsoshould be discarded. Thawed fish will be kept icedor refrigerated until feeding time. Frozen fish,once thawed, should NEVER be refrozen. Fishwaste will be kept in a separate refrigerator or aninsulated container, and it will be thrown away asquickly as possible.Food should be wholesome, palatable, freefrom contamination, and of sufficient quantityand nutritive value to maintain the animal in goodhealth (Anonymous, 1979-1984, 1995). Duringpreparation, each fish is inspected for quality andcut into pieces for training purposes only if necessary.Fish of smaller size are preferred over cutfish for this purpose. Fish will be fed cool, but notfrozen. Animals should be fed at least twice daily,unless otherwise stated by a veterinarian, butpreferably three to four times daily. Prior to feeding,individual buckets, labelled with the name ofeach animal, or engraved, are prepared with theirindividual ration according to their predetermineddiet. Vitamins and mineral supplements should begiven daily. Refer to Worthy (2001) for details.Trainers should never consume vitamins preparedfor animals. Tablets are usually hidden by insertingthem in fish gills or into the abdominal cavityand should be fed first (survey). To ensure thatconditions are appropriate and that methods forstorage and handling fish are proper, validation ofthe conditions and procedures are needed beforethey become policy and practice. They will be reexaminedat periodic intervals to ensure compliance,as well as when they are changed (Crissey,1998). Several surveyed facilities recommend to