TROUBLED WATERS - Whale and Dolphin Conservation Society

It is apparent from Figure 1, that, while there have been improvements in the percentage of animalskilled within ten seconds from 17 per cent in 1983, to 80 per cent in 2002, there remain one in five(20 per cent) of whales which do not die rapidly (in less than ten seconds), and whose survival can beas long as 40 minutes. From the tail of the lower survival curve in Figure 1, it is apparent that,despite alterations to the design of the harpoon, and increased training and monitoring of whalers,the decay line for whales taking more than ten minutes to die has effectively remained unalteredbetween 1996 and the most recent recorded data in 2002. One can interpret this as meaning that,for approximately 10 per cent of all whales killed (the intersection of ten minutes on the time x axis,with approximately 10 per cent on the survival line, y axis) by the Norwegians, death takes at leastten minutes. This figure has not significantly improved since 1996.The interpretation of the three criteria used to determine time of death is likely to be critical.Differences in the perception of ‘flipper movement’ (passive or active), or ‘sinking withoutswimming’ can create differences in TTD data. Whales are capable of sinking without swimmingduring normal activity (Ridgeway et al. 1984, Dierauf & Gulland 2001), and so sinking alone is notlikely to be a fully reliable indicator of non-viability.86A REVIEW OF THE WELFARE IMPLICATIONS OF MODERN WHALING ACTIVITIESIn practice, the use of the existing IWC criteria in the field by observers of the Japanese andNorwegian whaling operation has highlighted inconsistencies in their interpretation. For example, ina recent description of his experiences as a veterinary observer in the Norwegian hunt, Bruce (2003)states that the IWC criteria were used in an ‘inclusive’ fashion (relaxation of the jaw AND no Flippermovement AND no active movement). In contrast to this Norwegian example, recent data providedby Japan from the IWC Humane Killing Workshop in 2003 (Ishikawa 2003a) indicate that Japandoes not make the criteria ‘inclusive’ in general (but sometimes combine criteria such as motionlessAND slackened jaw, or motionless AND slackened pectoral fins) Table 1. For the largest part Japanuses ‘motionless’, a criterion which is not one of the IWC criteria, for determining TTD in mostanimals (Table 1, 514 out of 566 – 90 per cent).The IWC holds periodic scientific workshops to examine whale killing methods and associatedwelfare issues. It has been repeatedly noted at these workshops 4 that existing criteria are in need ofimprovement and that more reliable indicators of the point of sensibility and death should beproduced. An International Scientific Workshop on Sentience and Potential Suffering in HuntedWhales was hosted by the RSPCA in London in 2001 (RSPCA, 2003). The purpose was to reviewcurrent criteria for assessing insensibility in cetaceans and consider the welfare implications of thesecriteria for whales. A group of scientists and veterinarians with expertise in welfare, physiology andanatomy reviewed current data on times to death in whale hunts, and the current IWC criteria fordetermining the point of death in cetaceans. The group concluded that these criteria were notadequate to determine precisely the point of death, and it was agreed that it should be possible togreatly improve current indicators of sensibility and death in whales.If the scientific community is concerned that the existing IWC measures do not give confidence thatthe animal is dead, are there better measures? A preliminary study (Butterworth 2003a, 2003b)stemming from this workshop identified that the following measures would be likely to providereliable information on the sensibility of cetacea – “breathing rate when the animal is stimulatedaround the blowhole, electrocardiogram and heart rate, presence (or absence) of rhythmic swimmingactivity, and the temperature of the surface of the eye”.