An analysis of the decimation of the Antarctic blue whales (Balaenoptera musculus intermedia)

• Main Author: Berentsen, Carina
• Format: Master Thesis
• Language: Norwegian Bokmål
• Published: 2017
• Subjects: International Whaling Commission; whaling; cetacea; IWC; Blue whale; Antarctica; Antarctic; Norway; The Antarctic; Antarc*; Balaenoptera musculus
• Online Access: http://hdl.handle.net/10852/58003; http://urn.nb.no/URN:NBN:no-60736

In Antarctica, the failure to establish international agreement on regulations caused an overexploitation which reduced the number of blue whales from about 240 000 to less than 500. I have here taken a closer look at the two main reasons for this decimation: Firstly, a lack of appropriate statistical analysis, and secondly, a lack of international procedures to handle a multinational whaling fleet with conflicting motivations. The total catch of Antarctic blue whales during the last part of the 1930s was analysed by linear regression including power analysis. The purpose of this analysis was to investigate whether there existed enough evidence early in the history of Antarctic whaling to conclude whether or not the blue whale population was being overexploited. In classical hypothesis testing, a heavy weight is put to avoid Type I errors, that is, concluding that there is an effect (declining population) when in reality there is none (stable population). A much-used analogy is found in a modern court of law, where the risk of convicting an innocent person is kept so low that there in many cases is a large chance of letting a guilty person go free. In order to assess the statistical evidence for concluding in 1940 that the stock was seriously declining during the 1930s, the power for the test was calculated for a statistical design set up with the information available in 1933. A power analysis gives the minimum number of seasons (sample size) needed to draw conclusions about whether or not the population is actually declining. In this case, 6 seasons was sufficient, such that in 1940, there was a 95% probability of detecting that the declining stock was actually declining. This is equivalent to minimizing the chance of performing a Type II error: to conclude that a declining stock is not declining. The linear regression analysis did show a significant decline in the catches. I have in this study shown that there was sufficient statistical information available in 1940 to conclude that the hunting was in fact decimating the blue whale population. Therefore, the second part of my analysis was to identify the main reasons why the precautionary principle was not implemented to stop the systematic decimation. I have investigated the international reception of the main requests for establishing an international convention for the creation of a system to regulate whaling based on scientific and economic considerations. In the discussion of the many international meetings, a recurrent pattern appeared in the arguments opposing an international restriction of the blue whale catches. A major underlying motivation, more or less explicitly stated, was the concern for protecting the industry rather than the blue whale population. For some nations, an important issue was also to expand their fleet in order to obtain the same dominant influence as Norway and Great Britain had. In particular, it was important to find the reasons why even the International Whaling Commission (IWC), which was established in 1946, failed to protect blue whales. Without doubt, the single factor which made IWC so weak, was the right for every member to put down a veto against any recommendation they felt were going against their own national interests. My analysis has hopefully provided a valuable insight into the problems of not only establishing, but also enforcing international laws. In Antarctica, the failure to establish international agreement on regulations caused an overexploitation which reduced the number of blue whales from about 240 000 to less than 500. I have here taken a closer look at the two main reasons for this decimation: Firstly, a lack of appropriate statistical analysis, and secondly, a lack of international procedures to handle a multinational whaling fleet with conflicting motivations.