|Scientific Name:||Balaenoptera edeni Anderson, 1879|
|Infra-specific Taxa Assessed:|
<i>Balaenoptera</i> <i>brydei</i> Olsen, 1913
The taxonomy of Bryde’s Whales is not yet settled but recent years have seen progress towards its resolution. Most Bryde’s Whales analysed to date have been assignable to one of two sister clades: Balaenoptera edeni brydei is the larger, predominantly offshore form described by Olsen (1913) from animals taken by whalers operating out of Saldanha Bay and Durban, South Africa, while B. e. edeni is the smaller, predominantly coastal form described by Anderson (1879) from a specimen collected near the Sittang River, Gulf of Martaban, Myanmar, which is now held in the Indian Museum in Kolkata (Calcutta) (Sasaki et al. 2006, Kershaw et al. 2013). A few authors have considered these as separate species following Wada et al. (2003). However, a single species, B. edeni, is recognized by the Committee on Taxonomy of the Society of Marine Mammalogy (Committee on Taxonomy 2017) and the International Whaling Commission (IWC). The Committee on Taxonomy recognizes B. e. edeni and B. e. brydei as subspecies.
The small population of Bryde’s Whales in the northeastern Gulf of Mexico appears to be only marginally closer to B. e. edeni than to B. e. brydei or B. borealis (Rosel and Wilcox 2014). This taxon has been assessed separately for the IUCN Red List as a subpopulation of B. edeni.
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 and speculated that it might be B. e. edeni. It differed in terms of migration, seasonality of reproduction, fecundity, and prey types (Best 2001). Best 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. Subsequent phylogenetic analysis has shown the inshore form to be closer to B. e. brydei than to B. e. edeni (Penry 2010).
To distinguish B. e. brydei from B. e. edeni, the former is variously called the “offshore”, “large-type”, or “ordinary” Bryde’s Whale. In the event that B. brydei and B. edeni become recognized as separate species, the common name "Bryde's Whale" will likely be retained for B. e. brydei and Eden’s Whale should be used for B. e. edeni as a subspecies or species. The name “Pygmy Bryde’s Whale” has been used for B. e. edeni, but in the past has also been applied to specimens of B. omurai (Wada et al. 2003), which is now known to be a separate species outside the Sei (B. borealis)/Bryde’s Whale clade (Sasaki et al. 2006).
Until 1972, Bryde’s Whale was recorded as Sei Whale in the International Whaling Statistics, although it had been separately recorded in Japanese whaling records as “Southern Sei Whale” since 1955 (Ohsumi 1977).
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Cooke, J.G. & Brownell Jr., R.L.|
|Reviewer(s):||Jackson, J., Zerbini, A.N., Taylor, B.L. & Reeves, R.|
The taxonomy (number and identity of species and subspecies) of Bryde's Whales is not yet resolved. IUCN Guidelines note that species should not be classified as Data Deficient for reasons of taxonomic uncertainty alone. Therefore, the Bryde’s Whale is assessed here as one species, with most individuals belonging to the larger pelagic subspecies B. e. brydei. The large-type Bryde’s Whale B. e. brydei has been reduced by whaling, but not to the extent that would result in an IUCN Red List threatened category within its worldwide range. The taxon is therefore listed as Least Concern. There are several subpopulations or subspecies that should be assessed separately and may warrant threatened categories. One of these, the Gulf of Mexico Whale, has been listed as Critically Endangered on the Red List (Corkeron et al. 2017).
|Previously published Red List assessments:|
|Range Description:||Because the number of species, subspecies, or subpopulations of Bryde's Whales 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.|
Large-type Bryde’s Whales occur in the Pacific, Indian, and Atlantic oceans between about 40°N and 40°S (Kato and Perrin 2009). At least one form also occurs in the Red Sea. Migration to tropical waters in winter is documented for the southeastern Atlantic subpopulation (Best 2001) and for the northwestern Pacific subpopulation (Kanda et al. 2007). The migration patterns of other populations are poorly known. Their occurrence in the North Pacific is generally confined to waters warmer than 20°C (Omura 1959, Sasaki et al. 2013), but they are also found in colder waters off the west coast of southern Africa and northward to at least 3°N (off Cameroon) in the Benguela Current (Best 2001).
Bryde’s Whales occur across the western and central North Pacific, mainly north of 20°N in summer and south of 20°N in winter. In the eastern North Pacific, they are rarely found as far north as southern California (U.S.A.), but they occur throughout the eastern tropical Pacific from the Gulf of California, Mexico southward to Peru (Wade and Gerrodette 1993). Phylogenetic analyses of available samples revealed that these whales were nominally B. brydei, of the type currently referred to as B. e. brydei (Kanda et al. 2007). They also occur throughout the rest of the tropical Pacific, and across the South Pacific southward to about 35°S, but with shifts in distributions between seasons (Miyashita et al. 1996). They occur off the coasts of Peru and Ecuador, including the Galápagos Islands, perhaps throughout the year (Castro et al. 2017), and off Chile in an upwelling area between 35° and 37°S (Gallardo et al. 1983). All of a small number of genetic samples of Bryde’s Whales from Chile were assigned to B. e. brydei, and genetic samples of whales from Peru were also assigned to B. e. brydei (Pastene et al. 2015).
In the southwestern Pacific, their distribution extends as far south as the North Island of New Zealand, where they occur year-round in the Hauraki Gulf (Baker and Madon 2007), and these whales have been genetically identified as B. e. brydei (Wiseman 2008). Bryde’s Whales taken under special permits by Japan in the western South Pacific north of New Zealand were also assigned phylogenetically to B. e. brydei (Kanda et al. 2007), as was a specimen taken to the north near the Kermadec Islands (Omura et al. 1981, Wada et al. 2003).
Bryde’s Whales, some of which appear to be resident, are found in the Gulf of California (Sea of Cortez) (Urbán and Flores 1996): these have been assigned phylogenetically to B. e. brydei (Viloria et al. 2012).
Phylogenetic analyses revealed that the small “Bryde’s Whales” taken in the Philippines artisanal whale hunt (Perrin et al. 1996) included both B. e. edeni and B. omurai (Sasaki et al. 2006, LeDuc and Dizon 2002).
Bryde’s Whales that 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 (Yoshida and Kato 1999). Phylogenetic analyses show that they belong to B. e. edeni (Sasaki et al. 2006, Kershaw et al. 2013). A stranding from Hong Kong in 1994 (LeDuc and Dizon 2002) and a rescued river-trapped individual in eastern Australia (Priddel and Wheeler 1998) have also been found to be closely related phylogenetically to the B. edeni clade represented by the Junge (1950) specimen from near Singapore and the southwestern Japan whales noted above (Sasaki et al. 2006).
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 1980), as are the Bryde’s Whales found around the Maldives (Anderson 2005) and those of the northwestern Indian Ocean that were taken illegally by Soviet whaling fleets in the 1960s (Mikhalev 2000). All of these whales are assumed to be the offshore form B. e. brydei, and phylogenetically the whales from the southern Indian Ocean and the Maldives are in the B. e. brydei clade (Kershaw et al. 2013).
Kershaw et al. (2013) assigned Bryde’s Whales genetically sampled in coastal waters of Oman and Bangladesh to B. e. edeni. Whales sampled in the Maldives and whales taken offshore south of Java were assigned by Kanda et al. (2007) to B. e. brydei.
The B. edeni holotype (Anderson 1879) is from the Gulf of Martaban, Myanmar, 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. e. edeni, is from Sugi Island, Sumatra, Indonesia. Historical specimens held in Thailand are either B. e. edeni or B. omurai based on morphometrics (Yamada et al. 2008).
The identity of a few “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 of B. e. brydei, or B. e. edeni, or even B. omurai. Ottewell et al. (2016) reported a B. omurai based on genetics that stranded near Exmouth, Western Australia in March 2015.
A population of Bryde's Whales summers off the west coast of southern Africa and migrates to West African equatorial waters (Cameroon-Gabon) in winter (Best 2001). This population has not yet been sampled genetically.
There is a resident inshore population of small Bryde’s Whales off South Africa which shows some morphological and genetic differences from ordinary offshore Bryde’s Whales (Best 1977, 2001). Its main distribution is on Agulhas Bank between East London and Saldanha Bay (Best 2001). This population is closer phylogenetically to B. e. brydei and B. borealis than to B. e. edeni (Penry 2010).
Elsewhere in the Atlantic the distribution of Bryde’s Whales is not well known. They are observed regularly as far north as the Canary Islands and Madeira between June and November (Alves et al. 2010) and occasionally around the Azores (Steiner et al. 2007). One Madeira whale was identified genetically as B. e. brydei (Luksenburg et al. 2015). Bryde’s Whales are rarely found as far north as Cape Hatteras in the northwestern Atlantic (Rice 1998) and at least some of the records from the coast of the southeastern U.S.A. are a recently recognized taxon (subspecies or possibly species) that is found mainly in the Gulf of Mexico (Rosel and Wilcox 2014, Rosel et al. 2016). Bryde’s Whales have not been reported in the Mediterranean Sea (Reeves and Notarbartolo di Sciara 2006).
Bryde’s Whales occur throughout the wider Caribbean Sea (Ward et al. 2001). Four Bryde’s Whales stranded in Aruba, southern Caribbean, were identified phylogenetically as B. e. brydei (Luksenburg et al. 2015).
Bryde’s Whales occur year-round throughout coastal waters of Brazil (Zerbini et al. 1997) and strand regularly in southeastern Brazil (De Moura and Siciliano 2012). Samples of whales from Brazil have been assigned phylogenetically to B. e. brydei. However, considerable divergence was found between Bryde’s Whales from Brazil and those from Peru and Chile, which suggests that there are no direct movements of this species between the Atlantic and the Pacific (Pastene et al. 2015).
Native:American Samoa; Angola; Anguilla; Antigua and Barbuda; Argentina; Aruba; Australia; Bahamas; Bahrain; Bangladesh; Barbados; Belize; Benin; Bermuda; Bonaire, Sint Eustatius and Saba (Saba, Sint Eustatius); Brazil; Cambodia; Cameroon; Cape Verde; Cayman Islands; Chile; China; Cocos (Keeling) Islands; Colombia (Colombian Caribbean Is.); Comoros; Congo; Congo, The Democratic Republic of the; Cook Islands; Costa Rica; Côte d'Ivoire; Cuba; Curaçao; 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 ; Montserrat; Morocco; Mozambique; Myanmar; Namibia; Nauru; 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 Barthélemy; Saint Kitts and Nevis; Saint Lucia; Saint Martin (French part); Saint Vincent and the Grenadines; Samoa; Sao Tomé and Principe; Saudi Arabia; Senegal; Seychelles; Sierra Leone; Singapore; Sint Maarten (Dutch part); 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 – southeast; Atlantic – eastern central; Atlantic – southwest; Atlantic – northwest; Atlantic – western central; Atlantic – northeast; Indian Ocean – eastern; Indian Ocean – western; Pacific – northeast; Pacific – southeast; Pacific – southwest; Pacific – northwest; Pacific – eastern central; Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
North and Equatorial Pacific
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 made by Japanese fleets during 1971-79 and by Soviet fleets during 1966-79. Bryde’s Whales were also caught from whaling stations in Taiwan during 1976-80, from the Ogasawara (Bonin) Islands (Japan) during 1946-52 and 1981-87, and by a pelagic factory catcher based in the Philippines that operated during 1983-1985 (Perrin 2006, IWC 2008). Japanese pelagic catches resumed in 2000 under scientific permit (50 per year) but were discontinued after the 2016 season.There have been artisanal fisheries in the Philippines (until 1997) and Indonesia (Barnes 1991) taking small “Bryde’s Whales” (Dolar et al. 1994), but the catches consisted at least partly of Omura's Whales (LeDuc and Dizon 2002).
Prior to 1972, Bryde’s Whales were not distinguished from Sei Whales in International Whaling Statistics. Bryde’s Whales have been distinguished from Sei Whales in Japanese national catch statistics from 1962, and in whaling company records from 1955, but in sighting records only from 1972 (Ohsumi 1977). An additional problem has been inaccurate catch records: for example, Kondo and Kasuya (2002) reported that catches of Bryde’s Whales by Japanese operations around the Ogasawara Islands during 1981-87 were falsely reported as totalling 2,659, in order to keep within catch limits, but that the true total was 4,162. In some cases, the pre-1972 species breakdown of “Sei” Whale catches can be determined from original records, or estimated, 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. The IWC Scientific Committee determined “low”, “best”, and “high” estimates of 20th century Bryde’s Whale catches in the North Pacific, totaling about 13,000, 17,000, and 27,000 respectively (IWC 2008), but the latest best estimate of the Bryde’s Whale catches in the North Pacific is about 20,000 (Allison 2017).
Bryde’s Whales were distinguished from Sei Whales in Peruvian catch statistics from 1973, and 3,589 are recorded as having been caught during 1973-83 (Allison 2017). Of the 2,639 “Sei” Whales reported caught during 1967-72, the majority were probably Bryde’s Whales, judging from the catch composition in 1973-77.
The current abundance estimate for the western and central North Pacific (west of 165°W) accepted by the IWC Scientific Committee is 26,300 (coefficient of variation (CV) = 18.5%) based on surveys conducted in summer during 1988-2016 (Hakamada et al. 2017, IWC 2018).
The most recent accepted abundance estimate for the East China Sea stock is 137 (IWC 1996). It was subject to whaling in southwestern Japan until the early 1970s, and may have been depleted (Omura 1977). Using photo-identification, Pheothep et al. (2015) estimated a population of 63±8 Bryde's Whales in the upper Gulf of Thailand. No other population estimates are available for southeast Asian waters.
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 and extending westward towards Hawaii) from data collected during 1986-90.
An IWC/International Decade of Cetacean Research —later Southern Ocean Whale and Ecosystem Research — 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 methods. More recent surveys (2000-17) have been confined to certain coastal regions of Panama, Peru, Ecuador, and the Galápagos: 102 individuals were sighted including 4 resightings across years (Castro et al. 2017).
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 have been Bryde’s Whales (IWC 1980). In addition, the majority or all of the 641 “Sei” Whale taken off Cape Lopez, Gabon during the 1950s are believed to have been Bryde’s Whales (Ruud 1952). Of the over 5,000 “Sei” Whales recorded as caught off Brazil during 1948-77, at least some were Bryde’s Whales: Omura (1962) and Williamson (1975) suggested that only 8% of the catches were Bryde’s Whales but most subsequent sightings and strandings of Sei/Bryde’s Whales in Brazilian waters have turned out to be Bryde’s Whales (Zerbini et al. 1997).
In the western South Pacific, the number of Bryde’s Whales in the Hauraki Gulf was estimated to be 100-183 using photo-identification (Tezanos-Pinto et al. 2017).Northern Indian Ocean
Bryde’s Whales are distributed throughout the northern Indian Ocean (Arabian Sea and Bay of Bengal) but no population estimates exist for either region. During the 1960s, over 1,000 Bryde’s Whales were taken illegally by Soviet pelagic whaling operations in the Arabian Sea (Mikhalev 2000).
There is no comprehensive current worldwide population estimate for Bryde’s Whales, but the above estimates for offshore areas of the North Pacific and Southern Hemisphere total nearly 80,000 whales, and can be assumed to consist primarily of B. e. brydei. Taylor et al. (2007) estimate the generation time to be 18 years, in which case the time window for assessing the species against the decline criteria would be 1962-2016. Bryde's Whale catches are known with reasonable accuracy for this period, after making reasonable allowance for likely Bryde’s Whale catches recorded as Sei Whales, and total about 30,000, most of which were in the North Pacific (Allison 2017). Therefore, the global population of Bryde's Whales was probably not substantially reduced by whaling over this period.
Balaenoptera edeni edeni may consist of a number of small inshore populations, for most of which estimates are not available or are in the low hundreds or fewer. Some of these are located in areas of intensive fishing and other human activity and should be assessed separately as adequate information becomes available.
|Current Population Trend:||Unknown|
|Habitat and Ecology:||The ecology of Bryde’s Whales differs among populations and it is hard to make generalizations. The resident South African small inshore form showed no marked seasonality in reproduction and fed mainly on Anchovy, Pilchard, and Jack Mackerel, while the offshore (ordinary) form bred primarily in autumn and fed primarily on euphausiids and myctophids (Best 1977). Kawamura (1977) found that Bryde’s Whales from the South Pacific and Indian Oceans fed solely on euphausiids, but Ohsumi (1977) and Watanabe et al. (2013) found that in the northwesterm Pacific they consumed Anchovy in addition to euphausiids. Bryde’s Whales caught in the Arabian Sea fed mainly on myctophids, Mackerel, and Sardines (Mikhalev 2000).|
|Continuing decline in area, extent and/or quality of habitat:||Unknown|
|Movement patterns:||Full Migrant|
|Use and Trade:||
Between 2000 and 2016, up to 50 Bryde’s Whales were taken annually under special permit by Japan in the western North Pacific, but there are currently no plans to continue this catch. This species was less affected by commercial whaling than some of the other large whale species.
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 (Tønnessen and Johnson 1982), although this regulation was not respected by Soviet whaling fleets in the 1960s, nor by the pirate whaling ship Sierra in the 1970s. However, some subpopulations such as the East China Sea and South African inshore stocks may have been reduced by whaling (Omura 1977, IWC 1980).
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 Ogaswara (Bonin) Islands until 1987. Pelagic whaling resumed in the western North Pacific in 2000 under special permits and continued until 2016 but catches were limited to 50 per year (25 per year from 2014) (Allison 2017). Like most cetaceans, Bryde’s Whales are occasionally by-caught in fishing gear. Records of vessel strikes are generally rare. However, bycatch and vessel strikes are poorly reported throughout much of the range of these whales. Vessel strikes were frequently reported in the Hauraki Gulf region (0.9 whales/year) during 1994-2014 and were of concern for this small local subpopulation (Constantine et al. 2015). No collisions were reported there in 2016-17, which may reflect the success of new voluntary measures to avoid collisions.
There have been artisanal fisheries in the Philippines (until 1997) and Indonesia (Barnes 1991) taking small “Bryde’s Whales” (Dolar et al. 1994), but the catches consisted at least partly of Omura's Whales (LeDuc and Dizon 2002).
The very small, apparently isolated, subpopulation of Bryde’s Whales in the northeastern Gulf of Mexico may be threatened by vessel traffic, commercial fishing, and oil and gas activities (Soldevilla et al. 2017, Corkeron et al. 2017). The taxonomic status and geographical range of possible local subpopulations of small-type Bryde’s Whales in the tropics have not yet been determined, and therefore it is difficult to assess potential threats to them.
|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 the Convention on International Trade in Endangered Species although Japan has held a reservation against this listing since 1983. The species (as B. edeni) is listed in Appendix II of the Convention on the Conservation of Migratory Species of Wild Animals.|
|Citation:||Cooke, J.G. & Brownell Jr., R.L. 2018. Balaenoptera edeni. The IUCN Red List of Threatened Species 2018: e.T2476A50349178.Downloaded on 24 September 2018.|
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