The Whale-bleak past, uncertain future

Transcription

1 The Whale-bleak past, uncertain future The history of whaling is a sorry one. Whalers have reduced populations of one species after another to fragments of their original levels, and then moved on to the next target. The blue whale, the largest animal that has ever lived reaching lengths of 30 m and more has been reduced this century to less than 5% of its initial numbers, and some species have suffered even worse fates. None has been driven to extinction, but this can be attributed more to luck than to foresight. The story begins a very long time ago. Records of whaling in the northern Atlantic date back at least 800 years, and by the late bowhead populations were declining rapidly. Sperm whaling virtually stopped about 1860, but the replacement of sperm 1 00s a major commercial operation had oil for lighting by the newly discovered developed. The industry's first collapse occurred in the 1700s, the result of depletion of stocks of right and bowhead whales. Attention then turned to the sperm whale, and to hunting grounds in the southern Atlantic and around Cape Horn into the Pacific. By the mid 1800s, right mineral oil was possibly the main reason. Up to that time, whales were still being harpooned by hand from rowing boats a perilous occupation. But in 1868 a Norwegian whaler, Svend Foyn, invented the harpoon gun and explosive harpoon, and mounted them on a steam-driven whaling whale numbers in the Southern boat. Now all whales, not just the slowswimming Hemisphere had been reduced to very low levels, and in the northern Pacific right and sperm, humpback, gray, right, and bowhead, could be taken. Operations expanded in the Atlantic and Pacific, and then, early this century, moved into Antarctic waters with the discovery of herds of the huge blue and fin whales. The next major development was the arrival of the first factory ship in the Southern Ocean in 1925, making whalers independent of bases on land or on the ice. In Antarctic waters, attention first focussed on the blue whale, and it dominated the catch until the mid 1930s. Then numbers collapsed and by the mid 1950s few were being taken not for want of trying. The second-biggest whale, the fin, was next to suffer the same fate. It dominated the catch until the early 1960s, when the numbers taken fell rapidly. Populations of the humpback whale also crashed in the early 1960s. Among the results was the closing of whaling stations at Tangalooma near Brisbane and North West Cape in Western Australia. Another, at Albany, W.A., switched its operations from humpback to sperm whales and kept operating until The next whale hunted in the Southern Ocean was the sei, virtually ignored while 3

2 the bigger whales were still available. Catches peaked in and then fell rapidly. However, this time the decline was largely due to international regulations restricting the size of the catches. The International Whaling Commission (IWC), set up in 1948 'to provide for the proper conservation of whale stocks, and thus make possible the orderly development of the whaling industry', was at last intervening before a stock was obviously depleted. The IWC sets annual catch limits for each species. In the Southern Hemisphere, these are now zero for all except the minke and sperm whale. The minke, which rarely reaches a length of more than 10 m, was ignored until It is the smallest of the great whales. The main whaling area in the Northern Hemisphere is now the northern Pacific Ocean. Although large-scale factory-ship operations did not begin there until the 1950s, the story has again been one of successive severe reductions of stocks, beginning with the biggest whales. The most complex models are for sperm whales, because of the complexity of their social structure and behaviour. First limits The IWC set catch limits from its inception. However, as they were not set for particular species, they did little to protect the hardest-hit whales. And they applied only in the Southern Hemisphere. The limits were stated in terms of a measure known as the Blue Whale Unit (BWU), which was based on the oil yield of different species. One BWU equalled one blue whale, or two fin whales, or 2 5 humpback whales, or 6 sei whales. The catch limits did not cover sperm whales. Until 1953, the annual quota was set at BWU, and from then until the mid 1960s it fluctuated around These limits represented a big reduction from the peak catch of nearly BWU in , but it was obvious early in the 1960s that numbers of the most soughtafter whales were still declining rapidly. About 1963 the Commission decided that blue and humpback whales should be totally protected. Two years later it adopted the principle that all catches should be reduced to below levels at which they could A sperm whale killed off Western Australia is attached to the whaling boat... be sustained indefinitely. The problem was to determine those levels. The job fell first to a committee of three specialists in population dynamics appointed by the IWC in 1961 to assess whale stocks in the Southern Hemisphere. It was later taken over by the IWC's Scientific Committee, made up of scientists appointed by the Commission's 17 member countries, representatives of various United Nations bodies, and other scientists appointed for their expertise. On their recommendation, quotas were cut heavily in the late 1960s.... and towed back to Albany. The scientists also recommended that quotas stated in terms of the Blue Whale Unit be replaced by catch limits for each species. However, the Blue Whale Unit was not finally discarded until , a year before the Commission adopted in principle its present management procedure, which came into force in This is based on the concept, widely used in fisheries management, of 'maximum sustainable yield' or MSY. In nature, animal populations tend to fluctuate around fairly stable levels unless major changes occur in their environment. If something causes numbers to fall below the normal level, the tendency will be for them to rise again. If they rise above it for some reason, they can then be expected to fall. In the case of whales, a population reduced by whalers should tend to rise towards its previous level. If a harvesting operation removes each year the number of The whaling industry revived strongly after whales that the population would otherwise World War II. Then catches of one baleen increase by in a year, numbers should stay species after another fell rapidly with the at the reduced level and the yield should be depletion of stocks and, in recent years, the sustainable indefinitely. tightening of international regulations. The graphs show what happened to catches of blue, At some population level, the sustainable humpback, fin, and sei whales. yield should reach a maximum the 4

3 In the Southern Hemisphere, populations of all species except the sperm, minke, and Bryde's whales are currently assessed at less than one-quarter of their initial levels. MSY. That population is referred to as the MSY level. Setting the quotas The IWC, at its meeting each year, divides the world's whales into three categories initial management stocks, sustained management stocks, and protection stocks. Under its rules, initial management stocks, defined as those more than 20% above the MSY level, may be reduced in a controlled manner to that level. Quotas set for sustained management stocks, those between 10% below and 20% above the MSY level, are designed to keep numbers at or near that level. Protection stocks populations more than 10% below the MSY level are fully protected from commercial whaling by IWC countries. The rules allow the IWC to aim for 'optimum' population levels other than the MSY figures. But so far it has not been able to find a better definition of the optimum than the MSY level. The Scientific Committee assesses whale populations before each IWC meeting, and recommends what classification each should be given and what catches should be allowed. In recent years, the Commission has adopted its recommendations virtually without change. The Chairman of the Scientific Committee since 1974 has been Dr Radway Allen, Chief of thecsiro Division of Fisheries and Oceanography from 1972 until 1977 and now an Honorary Research Fellow there. He was a member of the committee of population dynamics specialists appointed by the IWC in The Vice-Chairman also is an Australian, Mr John Bannister of the Western Australian Museum. Dr Geoff Kirkwood, a population dynamics specialist with the Division of Fisheries and Oceanography, is also a member. All three have played major roles in the difficult and inexact process of assessing present population sizes, MSY levels, and safe catch limits. The committee uses computer-based mathematical models that simulate as accurately as possible the processes that determine population size in making its assessments. Most of the models now in use have been developed by Dr Allen and Dr Kirkwood. Mr Bannister is convener of the committee's sperm whale working group. Stop Press The Inquiry into Whales and Whaling by Sir Sydney Frost has recommended that Australia oppose whaling. Its report calls for bans on whaling within Australia's 200-mile fishing zone and, from January 1, 1981, on imports of whale products. It also recommends that Australia remain a member of the IWC, 'the forum where its anti-whaling policy can best be pursued'. An Australian proposal that a zero catch quota be set for sperm whales in 'Division 5' (see page 6) has been adopted by the IWC. The Soviet Union, according to newspaper reports, plans to cease commercial whaling within 5 years. The member nations of the IWC at present account for about 90% of the total whale catch. Sperm and baleen The most complex models are for sperm whales, because of the complexity of their social structure and behaviour. These animals are related more closely to dolphins and porpoises than to the other whales. They are toothed whales, feeding on large prey such as squids, and they dive to amazing depths as much as 500 fathoms (about 1000 metres) for their food. The other whales, the baleens, feed near the surface, mainly on small shrimp-like krill. They are filter-feeders, taking mouthfuls of water and using their tongues to force it out through the boney baleen plates, which catch the food. Sperm whales form harems of a male with females, whereas the baleens move about in groups that are fairly evenly balanced between the sexes. The sperm whale harems the breeding groups spend their time in comparatively warm water, between latitudes of about 45 north and 40 south (the 40 parallel passes through the middle of Bass Strait). Most of the remaining mature males stay apart from the harems, in colder water closer to the Arctic and Antarctic. Again unlike the baleens, sperm whale males grow much bigger than the females, reaching lengths of 20 m and more compared with a maximum of about 13 m for the females. Naturally this makes the males more attractive to whalers. So an important question when the effects of whaling are The IWC set these quotas at its London meeting in June Sperm whale quotas for the northern Pacific were to be set later. The catch limits apply to the factory ship season and 1979 coastal season. 5

4 In setting quotas for sperm whale catches, the IWC divides the Southern Hemisphere into nine divisions. The Albany whaling station operated in Division 5, the area outlined, extending from longitude 90 E to longitude 130 E. being assessed is whether unattached males from the colder regions move up to take the place of harem leaders caught by the whalers. Little is known about the rates of interchange between the groups. Albany The sperm whales caught by Albany's Cheynes Beach Whaling Company were members of warm-water groups feeding near the edge of the continental shelf within about 50 km of land. Spotter aircraft were used to locate the whales, which were harpooned from sonar-equipped ships and towed ashore for processing. The Australian scientists devised a method for assessing the sperm whale population in the area from information provided by the whaling company on numbers sighted per day from the aircraft. This is a variation of the 'catch-per-unit-effort' system used in many assessments of fish, and whale, stocks. In simple terms, the method works this way. If, for example, the average number in the catchable size range sighted or caught per day in one season is four and in the next season two, and if whales have been caught in the interim, then the original population was about and about are left. Of course, many adjustments have to be made in the calculations for, among other things, additions to the population and natural deaths. The scientists have checked their sperm whale population model against the Albany operation's sighting and catch figures. On the basis of their findings, the Scientific Committee of the IWC at its meeting in London in June of last year put the males into the sustained management category and the females into the initial management slot. However, Mr Bannister, Dr Kirkwood, and Dr Allen later re-assessed the situation and told the whaling inquiry run by Sir Sydney Frost that the males in this area, extending from the centre of the Great Australian Bight to west of Cocos Island, should go into the protection category. They also said that, although the number of females was well above the MSY level, it would be prudent to stop catching them as well because the imbalance between the sexes was reducing the pregnancy rate. The Albany operation has closed down, but the quotas set in London for the factory-ship season and the 1979 coastal season 402 males and 159 females are still available to other whaling nations unless the IWC meets again and cancels them. How many? Direct counting and tagging, as well as catch-per-unit-effort methods, are used to assess whale populations. The best example of direct counting relates to the gray whales of the north-eastern Pacific. Every year the entire stock migrates from its breeding ground on the Mexican coast to its Arctic feeding waters. The grays travel close to the Californian coast, and observers on headlands can make an accurate count. The current population of this sustained management stock is about The catch quota is 178, available only on a non-commercial basis to Aborigines of the Soviet Arctic regions. Another attempt at direct counting is proceeding along Australia's coasts. In projects sponsored by the Departments of Primary Industry and of Environment, Housing and Community Development, regular counts are made from aircraft of migrating groups of the much-depleted humpback whale. This is a less-exact process, and 10 years' counting may be needed before we know whether numbers are changing, let alone the rate of change. Whales generally produce young at rates well below one per year, so they cannot build their numbers up quickly. The maximum potential growth rate is about 5% per year, and that is unlikely to be achieved anywhere. The other two counting methods can be used only with whale populations that are being harvested. Tagging, which involves marking whales and recording the marks recovered in whaling operations, was used widely before World War II and on a smaller scale more recently. It has produced little reliable information on the size of populations, but has provided useful data on migrations and survival rates. The standard mark is a numbered metal dart fired Humpback whales caught off Tangalooma. Counts from aircraft are now being made off Australia to determine whether numbers of this much-depleted species are increasing. Tangalooma whaling station near Brisbane. Its operations ceased with the collapse of humpback whale numbers in the early 1960s. 6

5 The great \ Whales some of their characteristi s type species usual mature length where they are found toothed sperm m (males) m (females) world-wide distribution; breed in tropical and temperate oceans baleen (slow swimmers) right bowhead m m world-wide distribution; breed in temperate coastal areas restricted to Arctic waters, where they breed close to the edge of the ice gray humpback m m both species breed in warm coastal waters and migrate close to the coast to feeding grounds in colder latitudes; the gray whale is found only in the northern Pacific Ocean baleen blue m these species breed in warm open ocean (fast and are found world-wide; all except Bryde's fin m swimmers) whale migrate to feeding grounds in the sei m colder latitudes minke 8-11 m Bryde's m into the whale's blubber from a modified IWC requires its members to provide adequate shotgun. data from their operations. Some pro The catch-per-unit-effort method is by vide only the minimum of information far the most important. Quite good data are while others give much valuable detail. available from about 1930 when Norway, one of the main whaling nations at the time, Age of whales set up the Bureau of International Whaling To operate the mathematical models and Statistics. Because of this, scientists have derive catch limits, a great deal of information been able to make estimates that they is needed besides estimates of initial regard as fairly accurate of initial and present and current populations. For example, populations of some of the heavily dep natural mortality rates need to be known. leted species. For example, they put the These obviously cannot be measured initial fin whale population in the Southern directly, but can be estimated from data on Hemisphere at about and the current the age structure of whale populations. population at about With less Scientists have found they can determine certainty, they have derived figures of the age of baleen whales by counting the about for the initial and for layers in waxy plugs that form in their ears the current blue whale populations in the rather like counting the growth rings of Southern Hemisphere. The equivalent trees. figures from the northern Pacific are just Age structure information is also used to 6000 and work out how old whales normally are when For some species, notably the right and bowhead, which were heavily exploited in the early days of whaling, population estimates can be little better than guesses. The same applies in the Southern Hemisphere for Bryde's whale, which has so far remained unexploited. This is a rather bigger but much less-abundant animal than the minke, the only baleen whale now caught under IWC rules south of the equator. Bryde's whale is at present protected 'pending a satisfactory estimate of stock size'. Catch-per-unit-effort data are usually based on the number of whales caught in a day's work by a catcher vessel. But adjustments have to be made for all sorts of things, notably differences in the size of vessels and whether sonar equipment is used to follow whales under water. The Expressions of opposition to whaling have become common in recent years. This demonstration in Canberra coincided with the opening of the IWC meeting there in June they reach the permitted size range for whaling. The age of sexual maturity is another important piece of information that can usually be determined from the ear plugs. Some useful information on the proportion of females in a group giving birth in a year can be obtained from a count of the numbers pregnant among those caught, but it is difficult to make an accurate allowance for the fact that females with calves are protected. For the baleen whales, the Scientific Committee has generally adopted 60% of the unexploited level as the population figure at which the maximum sustainable yield should be obtained. Nobody suggests that this is more than an approximation of the actual MSY level, but as a working figure it should be high enough to ensure that no population falls dangerously low. Figures for the sustainable yield at the MSY level are obtained using the mathematical models. Again, nobody claims more than a fairly rough degree of accuracy. To be on the safe side, the Commission sets quotas at 90% of the derived figures. The fact that catches are assessed each year pro- 7

6 vides considerable assurance that an unsus tainable quota will not be maintained for more than a few years. In the Southern Hemisphere, popula tions of all species except the sperm, minke, and Bryde's whales are currently assessed at less than one-quarter of their initial levels. So, if the present rules are maintained, it will be many years before they can be harvested again. As these species are not being caught, generally very little evidence emerges to show how their numbers are changing. However, one piece of evidence that reduced populations do, in fact, tend to grow and thus make a sustained catch possible comes from Iceland. A fin whale fishery has been operating there since The catching effort has remained almost constant and no significant trend has shown up in the yield. Presumably, therefore, the population has remained virtually constant despite the continuous catch. T o complicate matters, populations of some species may rise in response to deple tion of others because competition for the available food is reduced. Between the 1930s and 1960s, when blue and fin whales were being exploited heavily in the Southern Hemisphere, scientists observed an increase in the pregnancy rate and a decrease in the age of maturity of sei whales. Presumably these changes were producing an increase in the population. Seis were being taken only in small num bers at the time. The catchers The member nations of the I W C at present account for about 90% of the total whale catch. The biggest whalers are Japan and the U S S R, which operate factory ships. The Japanese are mainly interested in baleen whales, for their meat, while the Russians take mainly sperm whales for Some of these estimates are considerably more certain than others. Those for the right and Bryde's whales a r e the least certain. their unique oil. Some other members maintain coastal whaling operations, but the majority are no longer involved in the industry. One member, the United States, put eight species, including the sperm whale, on its Endangered Species List in This prevents their products from being taken into that country legally. The United States is, however, still allowing the badly depleted bowhead whale to be hunted by its Eskimoes. Outside the I W C, a number of countries including Peru, Chile, Portugal, Spain, and South Korea are continuing coastal whaling operations. Some are known to be taking whales from stocks that the Commission judges should be protected. At least one small factory ship is also operating outside the I W C ' s ambit. It has been registered in a series of different coun tries and is probably taking fin whales in the Southern Hemisphere, where they are protected. Ships like this are highly mobile, and the risk exists that one of them could find a large group of a severely depleted species somewhere and take the lot. A s p e r m whale d r a g g e d onto the b e a c h below Albany's Cheynes B e a c h whaling station. Another potential threat, this time to all the baleen species, is the possible develop ment of a large krill-harvesting industry in the Southern Ocean. Krill has been pro posed as a major food source for the world, and serious assessment has begun of its industrial potential. The more that is taken to feed people, the smaller will be the num ber of whales that the remainder can sup port. More about the topic Whales. K. R. Allen. In 'Population Dynamics of Fishes', ed. J. A. Gulland. (Wiley: New York 1977.) Jojoba a future oil crop? One of the most sought-after products of the whaling industry is sperm oil, taken from the blubber and head cavities of sperm whales. Its main use is in specialized lubricants for differentials etc., and other applications where pressures are high. Before the United States government ban ned imports of whale products in December 1970, it established a stockpile of sperm oil in case an emergency use arose for which no substitute was adequate. Sperm oil is a liquid wax; chemically it is 8 quite different from other animal (including whale) oils, which are fats. Chemists find waxes of this type very difficult to synthes ize in useful quantities. Responding to the import ban, American manufacturers have produced from animal fats and petroleum products various substitutes that meet the requirements of specific uses, and the sperm oil stockpile has been discontinued. But no sperm-oil-equivalent, able to be substituted over the complete range of uses, has come from the chemical industry. J o j o b a f r u i t c o n t a i n a u n i q u e v e g e t a b l e oil.

7 In the late 1960s, interest revived in an can be adjusted for effective pollination. develop in winter, can reduce fruit produc earlier discovery that a liquid wax could be extracted from the acorn-like fruit of a desert shrub of the American west, the much-publicized jojoba (pronounced hoho-ba). Just as the sperm whale is the only producer of this type of oil among animals, jojoba is the only plant known to produce a liquid wax. And its product is very similar Then a few more years will probably pass before the females begin producing reasonable quantities of oil-bearing seeds. As a planting cannot be judged successful until good yields have been obtained over a series of seasons, the prospects for jojoba in Australia are likely to remain uncertain until the late 1980s. tion. This seems to rule out areas such as the New England and Southern Tablelands of New South Wales as jojoba-growing locations. Whether the lighter and less-fre quent frosts experienced in other areas will have much effect on yields remains to be seen. I f the research shows that jojoba can be grown successfully in Australia, price and demand will determine whether growing it is a good proposition. Harvesting the fruit seems unlikely to be a major problem; it should be possible to develop a mechanical harvester using the principles of existing machines. to sperm oil. Tests in the United States indicate that jojoba oil could be substituted for the whale product in virtually all, if not all, its uses. These include, apart from lubricants, wax goods such as polishes and candles, cos metics, and various pharmaceutical pro ducts. Jojoba oil has some distinct advantages over sperm oil, and may well find many new applications if large quantities become available at a competitive price. Unlike sperm oil, it contains remarkably small amounts of impurities and is very homogeneous in chemical composition. Another advantage is its lack of odour. The problem at present, however, is that only very small quantities are being pro duced. Trial plantings of jojoba bushes began about 15 years ago, mainly in the United States, Israel, and Mexico, and some commercial plantations have now been laid out. But even if yields are as high as the planters hope, it will be many years before commercially significant quantities of oil become available. In Australia, State government bodies, CSIRO, farmers, and entrepreneurs have set up trial plantations in most States in the past 2 years. The bushes are being tested in many different environments. Since 1976, CSIRO'S Division of Plant Industry has es tablished plantations at thirteen locations ranging from Moomba in the South Austra lian desert to subtropical Murwillumbah near the northern New South Wales coast. Although jojoba is found in the wild only in arid areas, it may quite possibly perform better in a milder, moister climate. Wheat is a notable example of an arid zone native successfully cropped in gentler environ ments. However, at present we don't know where jojoba will grow most productively in Australia, or even whether it will yield satisfactorily in any areas. And it will be up to 10 years before the planting trials begin to give firm answers. Jojoba is a slow-growing, long-lived (100 years or more), many-stemmed bush, usually reaching a height of 3-4 m. Only after 3 years' growth can one distinguish the male plants from the females; this has to be done in plantations so that the sex ratio J o j o b a seedlings in a University o f M e l b o u r n e glasshouse. At that stage, if all has gone well, it should be possible to say what climates and soil types suit the bush best, and what yields can be expected. It should also be possible to begin selecting and propagating plants that will give improved yields. T h e CSIRO team, Dr John Begg and Mr Bob Dunstone, is maintaining a register of jojoba trials with the aim of drawing together experience from as many areas as possible. They are keen to hear from far mers and others who have planted jojoba. At present the main buyer of jojoba oil, a perfume manufacturer, is paying about $18 per kg for the very small quantities being offered for sale. However, a much bigger market than the perfume industry will be needed if jojoba is to become a significant crop plant. Experience in Israel suggests that a young plantation may produce about 1 tonne of oil per ha. As no large-scale plantations have reached maturity yet, potential yields at maturity are unknown. The price of jojoba oil is sure to fall as larger quantities become available. It is much too early to predict the ultimate size of the market for this product. Possibly jojoba plantations will supply part of the general lubricating oils market, and highpressure lubricants, as the price of petroleum rises in in the 1990s and beyond. Whatever the plant's future, jojoba's As well as running the CSIRO planting trials, the two scientists are growing and ability to survive and grow in arid areas has studying jojoba bushes in a controlled- been recognized in Australia for a long environment laboratory and glasshouses in time. Back in the 1930s, seed from Arizona Canberra. Their work is filling in some of was taken to Broken Hill as part of an effort the large gaps that exist in knowledge of to revegetate areas denuded by mining such basic matters as rates of photo operations. Two healthy bushes survive from that. synthesis and water use, the factors that induce flower development, and environ project. Another, of unknown origin and mental factors affecting fruit growth. They about the same age, is growing at Dimare also studying the process of maturation boola, Vic. Unfortunately, the only male of that leads to production of the first flower the three is the bush at Dimboola, so no l i t buds on a seedling. In the field this takes at tie jojobas were produced. But in 1977 the least 3 years, but in the laboratory the time CSIRO team planted a young male beside the to first bud can be cut to 9 months by pro Broken Hill females, and three fruit formed. viding optimum conditions for growth. The scientists are working on ways to Last year the scientists planned to hand propagate the bush. T o maintain the best pollinate the two females, in an attempt to lines of jojoba, methods will be needed to find out the potential yield of mature root cuttings, graft improved material onto bushes. The plan was foiled by the weather: rootstock, or propagate plants using tissue a severe hail-storm removed every leaf and culture. berry. From the studies in Australia and over seas, some of jojoba's preferences have 'Products from Jojoba: a Promising New become clear. T h e plants require wellcrop for Arid Lands.' Committee on drained sandy soil, and may be affected by Jojoba Utilization, National Research frost. A heavy one can kill young plants, Council. (National Academy of Sciences: and frost damage to the flowers, which Washington, D.C ) 9