(from "Research on Whales", ICR, 1995)
Dr. Fukuzo Nagasaki
To say that whaling has been conducted with total abandon is not consistent with the facts.
Toward the end of the 1930s, the International Agreement for the Regulation of Whaling led the way in developing restrictive regulations. Soon after the Second World War, the International Whaling Commission (IWC) was organized following the adoption of the International Convention for the Regulation of Whaling. Although measures for conserving whale stocks have been debated at each of the annual meetings of the IWC, in the end the Commission has been unsuccessful in developing effective methods of conservation and long-term utilization of whale stocks.
Of the numerous reasons for this failure, the most significant was the fact that the international community had but scant biological knowledge of whales during the 1950s when Antarctic whaling was at its peak. Whaling grew rapidly despite the absence of accurate estimates of the abundance of whales, a situation not foreign to fisheries in general. By the time a fish population size is subject to estimates, actual fishing undertaken has long surpassed the optimal level and entered an overfishing phase. Compared with fish stocks, whale stocks are easily depleted, while they are slower to replenish.
Although the life expectancy of whales differs from species to species, it is generally very long. Blue whales live as long as 120 years and sperm whales live 70 years, both exceeding the average life expectancy of humans. The long life expectancy means a low natural mortality rate and the coexistence of many age groups in a stock; this in turn means that any given catch has a significant impact on population abundance. Whales generally reach sexual maturity and become reproductive about 10 years after their birth. The gestation period is long - 11 months for baleen whales and 16 months for sperm whales. As with humans, the mother whale almost always has one baby at a time. The nursing period ranges from six months to two years. In other words, one mature male fin or blue whale is reproduced every two years, and one mature male sperm whale is reproduced every four or five years. Killing a mature cow whale will have a direct impact on the number of offspring.
The initial population size of Antarctic blue whales was estimated at somewhere between 180,000 and 200,000. The restoration ratio reached a maximum at a population size of 120,000, and the safe annual catch limit at that point was estimated to be about 4,000 whales. The actual number of catches, however, had already exceeded 15,000 in the 1930s, and was far more than 5,000 a year even after the war. Thus, conditions of overharvesting prevailed for many years, with the exception of a period during the war.
With regard to fin whales, the initial population size was 400,000, and the population size that would produce a maximum of surplus was about 230,000. Whereas the sustainable annual yield at this point was about 8,000 whales, more than 20,000 whales per year were harvested from the 1950s to the early 1960s. These figures show that for over ten years after the Second World War, the whale stocks in the Antarctic were subject to very harsh whaling conditions.
Even though whales are animals whose population can easily decline, the IWC was unable to take effective measures to control whaling activities during the postwar years when these activities rose to a high level. This was in part because, as I stated earlier, there was a paucity of biological information on whales, but also because the IWC relied on the overall catch quota in the BWU system as a control method. The BWU (Blue Whale Unit) method, after all, was designed initially for the purpose of adjusting the production of whale oil; conservation of whale resources was not its objective. It is now clear, however, that catch limits for resource conservation must be set for each species of whales.
Moreover, the BWU quotas changed very little - within a range of 14,500 to 16,000 animals - between the 1946/1947 and 1962/1963 pelagic seasons. No steps were taken to counter the declining size of the whale population. According to the population analysis conducted by the Three-Member Committee - a study group consisting of three scientists from non-whaling countries - the sustainable yield of blue whales during the 1962/1963 pelagic season was as few as 200 animals or less, as compared to the estimated maximum sustainable yield of 6,000 animals to be expected when the population is restored to its initial size. Restoration of the population, moreover, would require a period of 50 years. In the case of humpback whales, the sustainable yield at that time was 100 animals, as compared to the maximum sustainable yield was estimated at 1,000 animals. Restoration of this species would also take 50 years. With regard to fin whales, the actual level of sustainable yield was fewer than 7,000 animals as compared to the maximum sustainable yield of 20,000 animals. The actual catch of 28,000 fin whales in the 1961/1962 pelagic season indicates the severity of overharvesting.
The moratorium on whaling became an issue in the IWC for the first time in 1972, when the resolution adopted by the U.N. Conference on the Human Environment held at Stockholm was conveyed to the Commission. IWC's Scientific Committee responded negatively to the recommendation for a ten-year moratorium on whaling, fearing that "the moratorium will diminish research activities, when in fact the study should rather be expanded substantially."
In 1973, the Scientific Committee stated it saw no scientific justification for the moratorium. In the 1974 annual meeting of the IWC, the United States again proposed a 10-year moratorium on whaling. Based on this proposal, Australia proposed a revised plan, which came to be known as the New Management Procedure (NMP). The NMP began to be applied starting 1975, resulting in the reduction of the annual quota on Antarctic fin whale catches from 1,000 animals in the 1974/1975 pelagic season to 220 animals in the 1975/1976 season. In 1976/1977, fin whales were designated as Protection Stock, and the quota was reduced to zero. The quota for Antarctic sei whales was reduced abruptly after 1975, and the species was designated as Protection Stock in 1978. The quotas for sperm whales also decreased gradually after 1976, but their catches in Antarctic waters were small to begin with anyway. Meanwhile in the North Pacific, fin whales, starting in 1975, and sei whales, starting in 1978, were designated as Protection Stocks. The NMP, thus, can be said to have been effective.
A meeting of the IWC Scientific Committee was held in Cambridge, England, prior to the opening of the 34th annual meeting of the IWC in 1982. The Committee discussed population abundance of a number of whale species including small whales, but it devoted most of its time and effort to the evaluation of the population size of minke whales in the Antarctic and sperm whales in the Northwestern Pacific. The discussion led to the estimate of Antarctic minke whale population (of the size large enough to be eligible for catch) to be 305,000 animals. There was no agreement, however, as to the size of the annual sustainable yield, and a rather wide range of figures was proposed. Neither was there an agreement on the population size of sperm whales in the Northwestern Pacific, and thus there was no recommendation by the Committee. These developments led to the argument that whaling should be suspended since we could not effectively manage whale stocks because of our inadequate knowledge regarding each species of whales and the size of its stock.
Using this argument, the United States, the United Kingdom, and Australia proposed a ban on commercial whaling, which eventually crystallized into Seychelles' moratorium proposal calling for the phasing out of commercial whaling. Meanwhile, ten nations, including India in 1981, and five other nations, including Monaco in 1982, joined the IWC, reducing the group of whaling nations to a very small minority. The Seychelles proposal was adopted. The following was added to the Schedule to the International Convention for the Regulation of Whaling as 10 (e):
Notwithstanding the other provisions of paragraph 10, catch limits for the killing for commercial purpose of whales from all stocks for the 1986 coastal and the 1985/86 pelagic seasons and thereafter shall be zero. This provision will be kept under review, based upon the best scientific advice, and by 1990 at the latest the Commission will undertake a comprehensive assessment of the effects of this decision on whale stocks and consider modification of this provision and the establishment of other catch limits.
In short, the resolution was to reduce all the catch quotas to zero after a grace period of three years.
II. Japanese Research on Whales in the Antarctic
In 1982, the IWC adopted a temporary blanket moratorium on commercial whaling. The adoption was based on the alleged grounds that our scientific knowledge of whales was unreliable and that effective management was not possible based on such knowledge. Therefore, the argument went, all commercial whaling should be suspended until more reliable information could be obtained. The decision was accompanied by the collateral condition, stated above, that a comprehensive assessment of whale stocks should be completed by 1990 at the latest.
In other words, the decision was to review the measure (moratorium) scientifically, relying on the best available data. Naturally, countries which are interested in whaling must gather scientific information, based on new studies, on the whale species and stocks in which they are interested. Unless such new information is obtained, the reliability of knowledge cannot be improved, and a comprehensive assessment would be meaningless. In such a case, the objective of the Schedule 10 (e) above cannot be achieved.
The promoters of the moratorium argued that the available scientific information was considered unreliable because almost all of the information on whales and whaling had been obtained through commercial whaling activities and their catches, and was therefore biased. Reliable information, so went the argument, could not be obtained from biased data. To obtain highly reliable information, therefore, data must be gathered by scientifically designed studies having no commercial character whatsoever.
The species of whale in which Japan is the most interested is the minke whale in the Antarctic. To remedy the unreliability of the knowledge of the stock of this species and acquire scientific information necessary for their management, a plan to conduct research on Antarctic whales was formulated. The knowledge which was indispensable for the implementation of NMP was the estimation of population abundance and the natural mortality rate of the whale species in question. A crude estimate of the natural mortality rate of minke whales was available, but some researchers on the Scientific Committee argued that a mortality rate for each age group of whales was necessary.
Under the circumstances, Japan prepared a plan for research, and the primary purpose of which was to gather representative specimens of whales for the purpose of estimating the natural mortality rate for each age group of whales. Added as a parallel objective of the research was the collection of information for the study of ecosystems centering on whales in the Antarctic.
Under Article 8 of the Convention, member governments have right to issue permits for hunting whales for such scientific research. In 1987, the Japanese government submitted to the IWC a plan for a feasibility study on Southern Hemisphere minke whales and Antarctic ecosystems. The plan identified two major survey objectives.
One objective was the estimation of the biological parameters necessary for managing Southern Hemisphere minke whale stocks. The other was the study of the role played by whales in the marine ecosystem of the Antarctic Ocean. The plan stated that specimens would be gathered in Areas IV and V which would be surveyed in alternate years, and that it would take 16 years for the survey to be completed. The number of minke whale specimens to achieve the research objectives was scientifically computed to be 300 animals plus or minus 10 % per year. The plan envisioned a long-term, full-scale survey, and was far removed from the notion that information gathered over a period of a few years could be used to the upcoming comprehensive assessment of whale stocks. The considerable length of the proposed survey was to be expected because the parameters of whale stocks could not be determined by a short survey.
The survey consisted of two parts. One was estimation by sighting of the size of whale population in the survey area. The other was gathering systematically selected specimens from sighted stocks or animals, and studying the sex composition and age distribution of whales within the stock. By combining the information obtained by these two methods, the age distribution of whales within the survey area could be estimated. The survey ships for collecting specimens would sail along the predetermined track line, and collect specimens according to the specified method when they encountered a herd of whales.
There are various arguments surrounding the research. Some question the necessity of taking whales for research purposes, arguing that nonlethal methods should be suffice. For estimating the size of whale population, the most effective method is a systematically-organized sighting survey. There is no need to kill whales for this purpose. What scientists are trying to discover, however, is not limited to the size of whale populations. Knowledge of the sex and age distribution of the whale stock is crucially important if we are to determine the dynamics of the stocks, just as in the case of population dynamics analysis of human beings. A whale stock of a given size may be increasing, decreasing, or remaining at the same level, depending on its composition. Proper stock management is not possible without such knowledge. To find out the sex and age distribution of a whale stock, there is no other way, given the current level of technology, but analysis through specimen gathering.
At about the time, Japan began its research, the Scientific Committee of the IWC began its study of a new scheme of managing whales - the Revised Management Procedure (RMP). Unlike the earlier New Management Procedure, the RMP does not necessarily require information on the various parameters of a whale stock. Given the information of the size of the stock at a given moment in time and the size of the catches in the past, the stock can be managed safely while it is being utilized because of a feed-back mechanism of the RMP. There are some who argue that, under this scheme, information on the natural mortality rate and pregnancy rate is no longer needed, obviating the need for Japan's Antarctic survey. It is obvious, however, that, even under the RMP, stock management is more efficient if the MSYR (maximum sustainable yield rate) is set on the basis of the knowledge of the reproductive capacity of the stock.
To implement the RMP, it is necessary to conduct surveys to monitor periodically the sizes of whale stocks. The accuracy and reliability of these surveys are essential for the effective implementation of the RMP. The sizes of whale stocks in the future, as now, will continue to be estimated by sighting. How the stock will change in the future, however, depends on the sex and age distribution and the pregnancy rate of the whales within the stock. Therefore, surveys like the one which Japan is conducting now will have to be continued along with the implementation of the RMP.
The results of the survey conducted over the past five years were summarized and reported each year to the Scientific Committee. The results on age distribution reveal that young animals are relatively numerous in Area IV, and the number of older animals gradually decline as the average age rises. In Area V, on the other hand, the middle-age group is most numerous at times, depending on the year of survey. These variations in age distribution appear to be related to the movements of the groups, suggesting the need for continuing data gathering. Another important type of information obtained from past surveys has to do with the apparent habitat segregation between male and female whales, and between mature and immature whales, depending on time and location (particularly with respect to pack ice). Knowledge of this habitat segregation is essential to my understanding of the distribution and ecology of whales.
III. Research on Whales in the Antarctic : Future Prospects
Much biological information is now systematically collected by Japan's research on whales in the Antarctic. As stated earlier, the primary objectives of this broad and detailed research effort are twofold. The first objective is to estimate the natural mortality rate for each age, and the second is to study the ecosystems of the Antarctic, focusing on whales.
1. Estimation of natural mortality rate (M)
It was vital to reliably estimate the natural mortality rate (M) to ensure the effective management of whale stocks when this research project was developed and surveys were initiated.
Estimation of biological parameters is still important even after adoption of the RMP. For example, knowledge on natural mortality rates and recruitment rates contributes toward estimating maximum net recruitment rates which are the base for calculation of sustainable yields. Earlier, the shortness of the time series of age data from the population has caused the major difficulty in achieving this, and also in interpreting trends in age-at-maturity over time. The additional data provided by the continuation of the Japanese research can solve that problem. The RMP has been designed to be robust over a wide range of possible values of the maximum sustainable yield rate (MSYR). Refinement of this range for the Southern Hemisphere minke whale would allow even sounder management of this population under such a management procedure.
In addition to the mortality rate, verification or otherwise of the scientific relevance on the RMP's small management area can lead to a better management under the RMP. Although the small area under the RMP is presently set up with a 10 degree longitude sector, continuous research on the differentiation of stocks, and seasonal migration patterns, will allow for an improved choice. As "stock" definition is considered to be one of biological parameters, improving the knowledge on the stock with continuation of the special permit program can contribute towards improved implementation of the RMP.
Implementing the RMP involves several issues. First, unless the stock is precisely determined, the catch limit must be greatly reduced to introduce a sufficient margin of safety. Effective and safe management must be based on a dependable stock determination.
Secondly, it is necessary to ascertain the dynamics of the stock in question and its size must be monitored at a given interval. New annual quotas must then be set based on the results of monitoring. The more frequently monitoring surveys are conducted and the more accurate their results, the safer and more efficient a given effort to implement the RMP. The accuracy of monitoring holds the key to effective RMP implementation.
Whale stocks are monitored by sighting. The movements and distribution of these stocks are not annually constant. As surveys have shown, the distribution of major stocks may vary considerably from year to year. Relying solely on sighting surveys, therefore, may lead to wide fluctuations in the estimation of stock sizes. To evaluate the results of sightings correctly in reference to the stock size, the sex and age composition of the stocks in the survey area must be known. data on such composition becomes important information for species like minke whales which clearly show, in their distribution, a pattern of habitat segregation by sex and age group. For these reasons, implementing the RMP requires, along with estimation by sighting, specimen gathering to study stock composition.
Furthermore, continuous gathering of accurate data on age distribution of stocks enables M mentioned above to be estimated. data on such distribution also provides important information for identifying stocks. In the specimen gathering currently being conducted by Japan in Areas IV and V, the study of stock identification using DNA techniques is progressing and new data is being accumulated.
2. Monitoring the ecosystem in the Antarctic
The species composition of whale stocks in the Antarctic is known to have been changed drastically by previous large-scale whaling. Some scientists suggest that minke whales now occupy the niche previously occupied by large whales, especially blue and fin whales. To detect such changes in the marine ecosystem, it is extremely useful to first study the population abundance of whale species. For this, data on the population abundance of all species of whales must be obtained by sighting surveys. Such a task cannot be accomplished within a short time; a long-term research effort using a consistent method is needed. To this end, the result of the IDCR sighting surveys, together with the sighting result by specimen gathering vessels, will provide important information.
_