Yulia V. Ivashchenko

Emptying the oceans: a summary of industrial whaling catches in the 20th century

Late 19th century technological advances for capturing whales, when combined with the expansion of processing capabilities in the early 20th century, created an industry that could catch and quickly render virtually any whale in any ocean. Here, using the current International Whaling Commission (IWC) database and other sources, we provide the fi rst accounting of the total global catch by industrial whaling operations in the 20th century. In sum, we estimate that nearly 2.9 million large whales were killed and processed during the period 1900–99. Of this total, 276,442 were killed in the North Atlantic, 563,696 in the North Pacifi c, and 2,053,956 in the Southern Hemisphere. The years 1925–39 in the Southern Hemisphere and 1946–75 in both hemispheres saw the highest totals of whales killed. For the entire 20th century, the largest catches were of fi n, Balaenoptera physalus, and sperm whales, Physeter macrocephalus, with 874,068 and 761,523 taken, respectively; these comprised more than half the total of all large whales taken. As noted in other publications, when one species began to decline, another was sought and hunted to take its place. In addition to reported catches, it is now known that the USSR conducted illegal whaling for more than 30 years. The true Soviet catch totals for the Southern Hemisphere were corrected some years ago, and a more recent assessment of the actual number of whales killed by Soviet factory fl eet ships in the North Pacifi c between 1948 and 1979 has provided us with more accurate numbers with which to calculate the overall global catch. The estimate for the total global catch by the USSR is 534,204 whales, of which 178,811 were not reported to the IWC. Introduction In the 1860’s, the Norwegian whaler and sealer Svend Foyn introduced the steam-powered whale catcher and the exploding harpoon gun to the whaling industry (Tonnessen and Johnsen, 1982). In the 1870’s, he improved upon shore-based factory processing to a level that came to be considered a standard for the industry (Tonnessen and Johnsen, 1982). By the time the 20th century began, the era of modern whaling—at least in the Northern Hemisphere—was well under way. Sixteen shore whaling stations had been established in Norway by 1883 (Risting, 1922; Dickinson and Sanger, 2005), and others were in operation in Newfoundland, Greenland, Russia, and Japan. In 1903, another Norwegian, Christen Christensen, introduced the fi rst factory ship, the wooden steamship Telegraf, into the waters off Spitsbergen (Tonnessen and Johnsen, 1982). Their primary targets were blue, Balaenoptera musculus; fi n, B. physalus; and humpback whales, Megaptera novaeangliae. However, industrial whaling south of the equator did not begin to resemble operations in the north until 5 years into the 20th century. Between 1900 and 1903, the only whales processed industrially were humpbacks caught via net and brought to a shore factory in Whangamumu Bay in New Zealand, a factory that had been established in 1890. The average catch was 8 whales per year during the 20-year operation of this factory (Lillie, 1915; Allison, 2012). The fi rst shore factory in the Southern Ocean was established in Grytviken (Cauldron Bay) on South Georgia Island by the Norwegian Carl Anton Larsen, from the Compania Argentina de Pesca, in late 1904 (Tonnessen and Johnsen, 1982). In 1903, one humpback whale was killed by modern methods by Adolf Andresen in the Straits of Magellan, but his processing station was not established until 1905 (Tonnessen and Johnsen, 1982). Thus, between 1900 and 1908, more whales were captured by industrial whaling methods in the Northern Hemisphere. By 1909, however, whaling south of the equator had surpassed that in the north. This trend continued until 1993, when the catch of whaling operations became comparable in the two hemispheres and were focused largely on minke whales, Balae“Some of the larger factory vessels with their capacity of over 2,500 barrels of oil per day capture more in two days than the original fl oating factories of 1904 were able to carry away with them in an entire season. One modern factory ship can take more whales in one season than the entire American whaling fl eet of 1846 which number over 700 vessels.” Lt (j.g.) Quentin R. Walsh, U.S.C.G., 1938

Estimating historical eastern North Pacific blue whale catches using spatial calling patterns.

Blue whales (Balaenoptera musculus) were exploited extensively around the world and remain endangered. In the North Pacific their population structure is unclear and current status unknown, with the exception of a well-studied eastern North Pacific (ENP) population. Despite existing abundance estimates for the ENP population, it is difficult to estimate pre-exploitation abundance levels and gauge their recovery because historical catches of the ENP population are difficult to separate from catches of other populations in the North Pacific. We collated previously unreported Soviet catches and combined these with known catches to form the most current estimates of North Pacific blue whale catches. We split these conflated catches using recorded acoustic calls from throughout the North Pacific, the knowledge that the ENP population produces a different call than blue whales in the western North Pacific (WNP). The catches were split by estimating spatiotemporal occurrence of blue whales with generalized additive models fitted to acoustic call patterns, which predict the probability a catch belonged to the ENP population based on the proportion of calls of each population recorded by latitude, longitude, and month. When applied to the conflated historical catches, which totaled 9,773, we estimate that ENP blue whale catches totaled 3,411 (95% range 2,593 to 4,114) from 1905–1971, and amounted to 35% (95% range 27% to 42%) of all catches in the North Pacific. Thus most catches in the North Pacific were for WNP blue whales, totaling 6,362 (95% range 5,659 to 7,180). The uncertainty in the acoustic data influence the results substantially more than uncertainty in catch locations and dates, but the results are fairly insensitive to the ecological assumptions made in the analysis. The results of this study provide information for future studies investigating the recovery of these populations and the impact of continuing and future sources of anthropogenic mortality.

What's the catch? Validity of whaling data for Japanese catches of sperm whales in the North Pacific

The failure of international efforts to manage commercial whaling was exemplified by revelations of large-scale illegal whale catches by the USSR over a 30 year period following World War II. Falsifications of catch data have also been reported for Japanese coastal whaling, but to date there has been no investigation of the reliability of catch statistics for Japanese pelagic (factory fleet) whaling operations. Here, we use data of known reliability from Soviet whaling industry reports to show that body lengths reported to the International Whaling Commission (IWC) by Japanese factory fleets for female sperm whales caught in the North Pacific are not credible. In 1968/1969, Japanese whaling fleets in the North Pacific killed 1568 females, of which 1525 (97.3%) were reported as being at or above the IWCs minimum length of 11.6 m (legal-sized females, LSFs). By contrast, Soviet fleets operating during this period killed 12 578 females; only 824 (6.6%) were LSFs. Adjusting for effort, catches of LSFs were up to 9.1 times higher for Japan compared with the USSR, and even higher for very large females. Dramatic differences in body length statistics were evident when both nations operated in the same area. Significantly, the frequency of LSFs and very large females in the Japanese catch markedly declined after the IWCs International Observer Scheme in 1972 made illegal whaling more difficult. We conclude that the Japanese length data reflect systematic falsification of catch statistics submitted to the IWC, with serious implications for the reliability of data used in current population assessments. The apparent ease with which catch data were falsified in the past underscores the necessity of transparent and independent inspection procedures in any future commercial whaling.

Alaska marine mammal stock assessments, 2015

NOTE – NMFS is in the process of reviewing humpback whale stock structure under the Marine Mammal Protection Act (MMPA) in light of the 14 Distinct Population Segments established under the Endangered Species Act (ESA) (81 FR 62259, 8 September 2016). A complete revision of the humpback whale stock assessments will be postponed until this review is complete. In the interim, new information on humpback whale mortality and serious injury is provided within this report.

Stretching the truth: length data highlight falsification of Japanese sperm whale catch statistics in the Southern Hemisphere

Falsification of reports on Japanese catches of sperm whales (Physeter macrocephalus) is known to have occurred at both land whaling stations and in North Pacific factory fleets. Here, we conduct an analysis of pelagic sperm whale catches in the Southern Hemisphere: we compare true Soviet length data from the Yuri Dolgorukiy factory fleet during 1960–1975 to data for the same period reported to the International Whaling Commission (IWC) by Japan. Prior to implementation of the International Observer Scheme (IOS) in 1972, the Soviet fleet killed 5536 females, of which only 153 (2.8%) were at or above the minimum legal length of 11.6 m. During the same period, Japan killed 5799 females and reported that 5686 (98.5%) were of legal size, with 88.5% of the entire length distribution reported as being between 11.6 and 12.0 m. This unrealistic distribution, together with the fact that Japanese fleets were supposedly able to catch 37 times the number of legal-sized females as the Soviet fleet, indicates extensive falsification of catch data by Japan. Further evidence of misreporting is that females >11.5 m dropped to 9.1% of the Japanese catch after 1971, when the IOS made cheating much more difficult. That 99.6% of 10 433 males in the pre-IOS catch were also reported to be of legal size, indicates that illegal catches were not confined to females. We caution that the Japanese sperm whale data in the IWC Catch Database are unreliable and should not be used in population assessments. The ease with which illegal catches were apparently made underscores the past failures of the IWC to effectively regulate whaling.

Whaling catch data are not reliable for analyses of body size shifts

To the Editor — Clements et al.1 use length data from the International Whaling Commission’s (IWC) catch database to support their contention that a negative shift in body size reflects an ‘early warning signal’ prior to the collapse of stocks of blue, fin, sei and sperm whales. There are several problems with this analysis. First, length data for sperm whales were extensively falsified by both Japan and the Union of Soviet Socialist Republics (USSR). The USSR conducted extensive illegal whaling beginning in 19482, and submitted falsified data on both the length and sex of sperm whales to cover up extensive catches of animals below the minimum legal length (11.6 m)3. Clements et al. mention the absence of length data for Soviet Southern Hemisphere catches, but not for the North Pacific. This presumably means that they used the falsified North Pacific data, which were only recently replaced (without lengths) in the IWC database4. Similarly, it is now known that, for the same reason, Japan routinely falsified data on the lengths and sexes of sperm whales in shore-based whaling operations in the North Pacific5, and on lengths for pelagic factory fleets there and throughout the Southern Hemisphere6,7. Consequently, any analysis of sperm whales will be fatally flawed: using changes in the 95% mean size does not help when the data concerned are largely fabricated. The Clements et al. analysis also failed to account for the ageand sex-segregated nature of sperm whale distribution, in which catches in high latitudes were primarily of large males while those elsewhere were biased towards the much smaller females and juveniles. Consequently, the shift over time in Southern Hemisphere whaling effort from the ice edge northwards would have resulted in increasing proportions of smaller animals in the catch (even if length and sex were accurately reported). Another problem relates to Southern Hemisphere blue whales. In the early 1960s, catches shifted from ‘true’ blue whales in high latitudes to the significantly smaller pygmy subspecies (Balaenoptera musculus brevicauda)8,9, yet the authors did not account for this in their analysis. Furthermore, the reported shift in length for Antarctic blue whales occurred after populations had collapsed to 1% of their former abundance in 19608; thus, a decline in length should have been apparent well before this point. Any as-yet unknown falsifications for other species will further complicate such analyses. A recent study suggested that, with some exceptions, length data reported by Japanese whalers for catches of Southern Hemisphere fin whales are probably largely reliable10. To date, no one has conducted such an assessment for sei whales; however, the USSR actually over-reported catch numbers for both fin and sei whales to camouflage takes of other species2, which means that some of the North Pacific length data would have been from non-existent animals. It is indeed likely that over-exploitation of whale stocks resulted in a decline in average lengths over time, and length data might be able to identify signals of diminishing abundance. However, this is valid only if the length data are both reliable and correctly interpreted, and that is not the case for at least two of the species here. ❐