|Scientific Name:||Balaenoptera edeni|
|Species Authority:||Anderson, 1879|
Balaenoptera brydei Olsen, 1913
|Taxonomic Notes:||The identity and number of species in the "Bryde's Whale complex" is still unclear. There is an "ordinary" Bryde's Whale, with a worldwide distribution in the Pacific, Indian and Atlantic oceans, which grows to about 14 m in length, and one or more smaller forms which tend to be more coastal in distribution. The taxonomic status of the smaller forms is unclear.
B. edeni was originally described by Anderson (1879) from a specimen collected near the Sittang River, Myanmar, which is now held in Calcutta. It was small compared with "ordinary" Bryde’s whales, being apparently nearly physically mature at only 11.3 m in length (Rice 1998). Junge (1950) collected a further specimen (now held in Leiden) at Sugi Island, Indonesia (between Sumatra and Singapore), which he judged to be physically mature and "slightly over" 12 m, and identified it with Anderson's B. edeni.
B. brydei was described by Olsen (1913) from specimens taken off South Africa. Junge (1950) concluded that B. brydei was synonymous with B. edeni. This was accepted by most cetologists and management authorities until the 1990s.
Wada et al. (2003) described a new species, B. omurai, a finding that was confirmed by Sasaki et al. (2006). A source of confusion is that, before its description, specimens of B. omurai were reported as small or "pygmy" Bryde’s Whales (e.g. whales taken in the Solomon Sea (Ohsumi 1978b) and the Philippines (Perrin et al. 1996)). The phylogenetic analyses show clearly that B. omurai lies well outside the Sei/Bryde’s clade: it has a separate entry on this Red List.
Based on phylogenetic analysis, Wada et al. (2003) concluded that B. edeni (represented by Junge’s specimen) also lies outside the clade of Sei and Bryde’s Whales for one mtDNA marker and hence proposed that it be regarded as a separate species, although statistical support for the phylogeny was weak. From an analysis of the full mtDNA genome, Sasaki et al.(2006) concluded that the Junge specimen belongs to a sister clade of the "ordinary" Bryde’s Whales (i.e. more closely related to them than either is to the Sei or Omura's Whale). They agreed that it should be classified as a separate species (B. edeni) from other Bryde's Whales (B. brydei). However, the divergence is relatively shallow, and the two forms could reasonably still be considered subspecies. Data from more markers (including nuclear markers) are needed.
Yoshida and Kato (1999) found that whales from a population of "smallish" Bryde's Whales from southwestern Japan (modal length about 1 m shorter than western North Pacific Bryde's Whales – Omura 1962, Ohsumi 1980a) segregated out phylogenetically from other Bryde's Whales in the western North Pacific, and suggested that they may be a subspecies. Sasaki et al. (2006) found that they form a clade with B. edeni (sensu Junge’s specimen)
Best (1977) described a resident inshore form of Bryde's Whale off South Africa which is slightly smaller than the "ordinary" form of Bryde’s Whale found further offshore around South Africa, and differs in terms of migration, seasonality of reproduction, fecundity and prey types (Best 2001). He noted that Olsen's 1913 description of B. brydei was probably based on a mixture of this inshore form and "ordinary" Bryde's Whales caught off South Africa. In the absence of genetic analyses, the taxonomic position of the inshore form remains unclear.
Until more specimens of the putative B. edeni (sensu Sasaki et al. 2006) from more locations have been analysed morphologically and genetically, using more markers, it is too early to settle the taxonomy of the Bryde’s Whale complex: there may be one, two or more species, and/or subspecies, and intermediate forms may be found. In addition, nomenclatural uncertainty remains until the B. edeni holotype (Anderson, 1879) has been analysed genetically.
|Red List Category & Criteria:||Data Deficient ver 3.1|
|Assessor/s:||Reilly, S.B., Bannister, J.L., Best, P.B., Brown, M., Brownell Jr., R.L., Butterworth, D.S., Clapham, P.J., Cooke, J., Donovan, G.P., Urbán, J. & Zerbini, A.N.|
|Reviewer/s:||Taylor, B.L. & Notarbartolo di Sciara, G. (Cetacean Red List Authority)|
The taxonomy (number and identity of species) is not yet resolved. If there is more than one species, the less abundant species may be threatened. If it is all one species, then it should be classified as Least Concern.
|Range Description:||Because the number of species or subspecies is still unresolved, and because the different forms are not readily distinguishable at sea, considerable uncertainty remains with regard to the geographic range of each form.
Ordinary Bryde’s whales
“Ordinary” large-type Bryde’s whales occur in the Pacific, Indian and Atlantic oceans between about 40°N and 40°S or in waters warmer than 16.3°C (Kato 2002). Migration to equatorial waters in winter is documented for the southeast Atlantic population (Best 1996) and for the northwest Pacific population (Kishiro 1996). Migration patterns of other populations are poorly known
They are relatively common in the western North Pacific, mainly north of 20°N in summer and south of 20°N in winter. In the eastern North Pacific, they do not venture north of southern California (US), but there appears to be a resident population in the northern Gulf of California (Urbán and Flores 1996), and they occur throughout the eastern tropical Pacific (Wade and Gerrodette 1993). They occur throughout the tropical Pacific, and across the South Pacific down to about 35°S, but with shifts in distributions between seasons (Miyashita et al. 1995). They occur off the coasts of Peru and Ecuador but not during July to September (Valdivia et al. 1981), and off Chile in an upwelling area between 35°-37°S (Gallardo et al. 1983). In the southwestern Pacific, their distribution extends as far south as the North Island of New Zealand (Thompson et al. 2002).
Bryde’s whales occur throughout the Indian Ocean north of about 35°S. Those in the southern Indian Ocean appear to be large-type animals (Ohsumi 1980b), as are the Bryde’s whales of the northwest Indian Ocean, which were taken illegally by Soviet whaling fleets in the 1960s (Mikhalev 1997), and those around the Maldives (Anderson 2005).
In the South Atlantic, there is a population that summers off the western coast of southern Africa, and migrates to West African equatorial waters in winter (Best 2001). Elsewhere in the Atlantic the distribution of Bryde’s whales is not well known. The Bryde’s whale appears to occur year-round throughout Brazilian waters (Zerbini et al. 1997). Bryde’s whales occur in the Gulf of Mexico (Mullin and Fulling 2004) and throughout the wider Caribbean (Ward et al. 2001). They do not occur in the Mediterranean (Reeves and Notabartolo di Sciara 2006). They have been recorded as far north as Cape Hatteras in the northwest Atlantic (Rice 1998).
East China Sea
Bryde’s whales which occur off southern and southwestern Japan are now considered to belong to an East China Sea population, having earlier been thought to be a local resident population (Kato and Kishiro 1999). Phylogenetic analyses suggest that they are a subspecies of Bryde’s whales (Yoshida and Kato 1999) or belong to the separate species B. edeni (Sasaki et al. 2006).
South African inshore form
There is a resident inshore population of Bryde’s whales off South Africa which shows some morphological differences from ordinary Bryde’s whales (Best 1977, 2001). Its main distribution is between Cape Recife and Saldanha Bay (Best 2001). It may simply be a local form of ordinary Bryde’s whale, but its taxonomic status has yet to be investigated genetically.
Other small forms
Small-type “Bryde’s” whales that appear to be mature at small sizes have been found in various Asian waters and off Australia.
The B. edeni holotype (Anderson 1879) was found in the Gulf of Martaban, Andaman Sea. Further specimens were found on the Bay of Bengal coast of Myanmar (Anderson 1879) and in Bangladesh (Andrews 1918). The Junge (1950) specimen, used in recent studies as the genetic representative of B. edeni, is from Sugi Island, Sumatra (Indonesia) (close to Singapore).
A stranding from Hong Kong (China) and a rescued river-trapped individual in eastern Australian (Priddel and Wheeler 1998) have been found to be closely related phylogenetically to the “B. edeni” clade represented by the Junge (1950) specimen and the southwestern Japan whales (Sasaki et al. 2006, LeDuc and Dizon 2002).
Phylogenetic analyses reveal that at least some of the small “Bryde’s whales” taken in the Philippines artisanal fisheries (Perrin et al. 1996) were in fact B. omurai (Sasaki et al. 2006, LeDuc and Dizon 2002).
The identity of “Bryde’s whales” maturing at a small size (11-12 m) caught off western Australia (Bannister 1964) is unclear. They may be a local form, or related to small forms found elsewhere, or they may even have been B. omurai.
The identity of eight small “Bryde’s whales” stranded in Thai waters (Andersen and Kinze 1993) is also unclear.
Native:American Samoa (American Samoa); Angola (Angola); Anguilla; Antigua and Barbuda; Argentina; Aruba; Australia; Bahamas; Bahrain; Bangladesh; Barbados; Belize; Benin; Bermuda; Brazil; Cambodia; Cameroon; Cape Verde; Cayman Islands; Chile; China; Cocos (Keeling) Islands; Colombia; Comoros; Congo; Congo, The Democratic Republic of the; Cook Islands; Costa Rica; Côte d'Ivoire; Cuba; Djibouti; Dominica; Dominican Republic; Ecuador; El Salvador; Equatorial Guinea; Eritrea; Fiji; French Guiana; French Polynesia; Gabon; Gambia; Ghana; Gibraltar; Grenada; Guadeloupe; Guam; Guatemala; Guinea; Guinea-Bissau; Guyana; Haiti; Honduras; India; Indonesia; Iran, Islamic Republic of; Iraq; Jamaica; Japan; Kenya; Kiribati; Korea, Democratic People's Republic of; Korea, Republic of; Kuwait; Liberia; Madagascar; Malaysia; Maldives; Marshall Islands; Martinique; Mauritania; Mauritius; Mexico; Micronesia, Federated States of ; Morocco; Mozambique; Myanmar; Namibia; Nauru; Netherlands Antilles; New Caledonia; New Zealand; Nicaragua; Nigeria; Niue; Northern Mariana Islands; Oman; Pakistan; Palau; Panama; Papua New Guinea; Peru; Philippines; Pitcairn; Puerto Rico; Qatar; Réunion; Saint Kitts and Nevis; Saint Lucia; Saint Vincent and the Grenadines; Samoa; Sao Tomé and Principe; Saudi Arabia; Senegal; Seychelles; Sierra Leone; Singapore; Solomon Islands; South Africa; Sri Lanka; Taiwan, Province of China; Tanzania, United Republic of; Thailand; Timor-Leste; Togo; Tonga; Trinidad and Tobago; Turks and Caicos Islands; Tuvalu; United Arab Emirates; United States; Uruguay; Vanuatu; Venezuela, Bolivarian Republic of; Viet Nam; Virgin Islands, British; Virgin Islands, U.S.; Wallis and Futuna; Western Sahara; Yemen
|FAO Marine Fishing Areas:||
Atlantic – eastern central; Atlantic – northwest; Atlantic – southeast; Atlantic – southwest; Atlantic – western central; Indian Ocean – eastern; Indian Ocean – western; Pacific – eastern central; Pacific – northeast; Pacific – southeast; Pacific – southwest; Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
Prior to 1972, Bryde’s whales were not distinguished from sei whales in International Whaling Statistics, but in some cases the pre-1972 species breakdown of “sei” whale catches can be determined from original records, or approximated, based on current knowledge of the geographical and seasonal occurrence of sei and Bryde’s whales, or from the compositions of later catches in the same area and season (IWC 1997, 2006b). Bryde’s whales are distinguished from sei whales in Japanese national catch statistics from 1962, but in sighting records only from 1972 (Ohsumi 1978a).
In the North Pacific region, the International Whaling Commission (IWC) Scientific Committee (SC) recognises the following stocks: Western North Pacific Stock (west of 150°W, down to 2°S), Eastern Tropical (east of 150°W down to 10°S), East China Sea, and Gulf of California (IWC 1996). The region of the South China Sea, and the Philippines and Indonesian and Solomon archipelagos are considered habitat of small-type Bryde’s whales and Omura’s whale, and not included in any putative stocks for ordinary Bryde’s whales, although the latter probably also occurs there (see above).
The IWC SC has not assessed Southern Hemisphere Bryde’s whales in recent times, but the IWC Schedule lists the following stocks, based on recommendations from the IWC Scientific Committee in 1980: western South Pacific (west of 150°W, but excluding Solomon Islands area), eastern South Pacific (south of 10°S), southern Indian Ocean, northern Indian Ocean, South African Inshore, and South Atlantic.
Western North Pacific
The currently accepted abundance estimate for the western North Pacific is 26,000 (CV=24%) based on surveys conducted during 1998-2002. Catches of Bryde’s whales from coastal stations in Japan are thought to have begun in 1906 and continued uninterrupted until 1987 when Japan adhered to the IWC’s commercial whaling moratorium. Pelagic catches were taken by Japanese fleets during 1971-79 and by Soviet fleets during 1966-79. Bryde’s whales were also caught from Taiwan during 1976-80 from the Bonin islands (Japan) during 1946-52 and 1981-87, and offshore whaling from the Philippines during 1983-1985 (IWC 2006a). Japanese pelagic catches resumed in 2000 under scientific permit (50 per year).
An annual catch series totalling over 20,000 whales for the period 1911-87 was estimated by the IWC SC in 1996 (IWC 1997). Since then, some new information has come to light: for example, Kondo and Kasuya (2002) reported that catches of Bryde’s whales by Japanese operations in the Bonin Islands during 1981-87 had been falsely reported as 2,659, in order to keep within catch limits, but that the true total was 4,162. According to a 1995 population assessment by the IWC SC, the population was reduced, in the worst case, by 49% during 1911-96 (IWC 1996). Work on a revised catch series and assessment is in progress (IWC 2007).
Eastern tropical Pacific
Wade and Gerrodette (1993) estimated 13,000 (CV= 20%) Bryde’s whales for the eastern tropical Pacific (in an irregularly-shaped area of 19 million km² between about 15°S and 25°N) from data collected during 1986-90.
An IWC/International Decade of Cetacean Research (IDCR) —later Southern Ocean Whale and Ecosystem Research (SOWER) — survey of the eastern equatorial Pacific (10°S-10°N, 80°-110°W) in December 1982 yielded an estimate of 17,000 (CV=32%) Bryde’s whales (IWC 1984), but the estimate should be recalculated using current methodology.
Bryde’s whales were distinguished from sei whales in Peruvian catch statistics from 1973, and 3,589 are recorded caught during 1973-83 (IWC 2006a). Of the “sei” whales reported caught during 1968-72, an estimated 1,953 were Bryde’s whales, to give a total Bryde’s catch of 5,542 during 1968-83.
Other North Pacific stocks
The most recent accepted estimate for the East China Sea Stock is 137 (variance not calculated), and for the Gulf of California stock 235 (173-327) (IWC 1996). The East China Stock was subject to whaling in southwestern Japan until the early 1970s, and may have been depleted (Omura 1977).
The Southern Hemisphere stocks of Bryde’s whales have not been re-assessed during the past 25 years, but the abundance estimates accepted at the time were: southern Indian Ocean − 13,854; western South Pacific − 16,585; and eastern South Pacific – 13,194 (IWC 1981). These were not based on what are currently accepted methods of survey design and analysis. Based on a majority recommendation of the Scientific Committee, the IWC subsequently reset the classification of these stocks to “zero catch limit pending a satisfactory estimate of stock size” (IWC 1983).
Of 1,705 “sei” whales reported taken off Chile during 1932-79 (IWC 2006a), an unknown proportion were Bryde’s whales (Gallardo et al. 1983).
The South African Inshore stock was estimated at 582 (±184) in 1983 (Best et al. 1984). Over 2,000 Bryde’s whales are recorded caught by modern whaling during 1911-67 in Cape Province, South Africa, including 1,300 during 1947-67 (IWC 2006a) of which most were from the inshore stock (IWC 1980).
No population estimates are available for the remainder of the South Atlantic. Of 2,536 “sei” whales taken by the pirate whaling ship Sierra in the South Atlantic during 1969-76, the majority are believed to be Bryde’s whales (IWC 1980). Of the over 5,000 “sei” whales recorded caught off Brazil during 1948-77, at least some were Bryde’s whales, but possibly only 8% (Omura 1962, Williamson 1975).
Apart from a population estimate for the Southern Gulf of Mexico of 40 (13-129) animals (Mullin and Fulling 2004) there are no abundance estimates for the North Atlantic. Some of the “sei” whales recorded around the Straits of Gibraltar in the first half of the 20th century may have been Bryde’s whales (Aguilar 1984).
Small-type Bryde’s whales
No population estimates exist, and are unlikely to become available until methods are developed to identify them at sea and their range is better known.
|Habitat and Ecology:||
A long- standing prohibition on the operation of factory ships north of 40°S except in the North Pacific north of 20°N meant that Bryde’s whale populations largely escaped the consequences of whaling suffered by baleen whale species that feed in higher latitudes, although this regulation was not respected by Soviet whaling fleets in the 1960s, nor by the pirate whaling ship Sierra in the 1970s (see above). However, some populations such as the East China Sea and South African Inshore stocks may have been reduced by whaling.
Pelagic whaling for Bryde’s whales was suspended in the North Pacific from 1980 following a ban by the IWC on most factory ship whaling, but catches continued from the coast of Japan and the Bonin Islands until 1987. Pelagic whaling resumed in the western North Pacific in 2000 under special permits issued by the Japanese authorities, but to date catches have been limited to 50 per year (IWC 2006a). Like most cetaceans, Bryde’s whales are occasionally by-caught in fishing gear, but they do not appear to be especially susceptible. Records of vessel strikes are also rare.
There are ongoing (or at least recent) artisanal fisheries in the Philippines and Indonesia taking small “Bryde’s whales” (Dolar et al. 1994, Perrin et al. 1996, Reeves 2002), but the catches include at least some specimens of B. omurai (LeDuc and Dizon 2002). It is unclear whether one or more forms of Bryde’s whale are also involved. In the absence of better information on the identity of the catches, it is not possible to judge whether these fisheries constitute a conservation threat.
|Major Threat(s):||The Bryde’s whale was the incidental beneficiary of IWC area restrictions on factory ship whaling that were originally designed to protect the low-latitude winter breeding grounds of other baleen whale species, at a time when the Bryde’s whale was not yet recognised as a distinct species by the whaling industry (Tønnessen and Johnsen 1982). The Bryde’s whale is included in Appendix I of CITES although Japan has held a reservation against this listing since 1983. The species (as B. edeni) is listed in Appendix II of CMS.|
|Conservation Actions:||The Bryde’s whale was the incidental beneficiary of IWC area restrictions on factory ship whaling that were originally designed to protect the low-latitude winter breeding grounds of other baleen whale species, at a time when the Bryde’s whale was not yet recognised as a distinct species by the whaling industry (Tønnessen and Johnsen 1982). The Bryde’s whale is included in Appendix I of CITES although Japan has held a reservation against this listing since 1983. The species (as B. edeni) is listed in Appendix II of CMS.|
|Citation:||Reilly, S.B., Bannister, J.L., Best, P.B., Brown, M., Brownell Jr., R.L., Butterworth, D.S., Clapham, P.J., Cooke, J., Donovan, G.P., Urbán, J. & Zerbini, A.N. 2008. Balaenoptera edeni. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 12 March 2014.|
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