Information about Southern Right Whale

Southern Right Whale
A Southern Right Whale in the breeding grounds at Peninsula Valdés in Patagonia. A Southern Right Whale in the breeding grounds at Peninsula Valdés in Patagonia.
Conservation status
Conservation Dependent (IUCN)
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Cetacea Suborder: Mysticeti Family: Balaenidae Genus: Eubalaena Species: E. australis Desmoulins, 1822
Binomial name
Eubalaena australis
Range map.

The Southern Right Whale (Eubalaena australis) is a baleen whale, one of three species formerly called classified as the Right Whale belonging to the genus Eubalaena. Around 7,500 Southern Right Whales are spread throughout the southern part of the Southern Hemisphere.

Taxonomy

The Southern Right Whale was described as Balaena australis by Desmoulins in 1822, though later transferred to the genus Eubalaena described by Gray in 1864. Later reclassified as a subspecies of the North Atlantic Right Whale (E. glacialis), it is once again considered a separate species. Furthermore it may one day be reclassified in its original genus as scientists see greater differences between the three Balaenoptera species than between the Bowhead Whale, only member of the original genus Balaena and the other three right whales. It therefore seems likely that all four species will be placed in one genus in a future review.^[1]

Synonyms for E. australis have included B. antarctica (Lesson, 1828), B. antipodarum (Gray, 1843), E. temminckii (Gray, 1864).^[1]

In dealing with the three populations of Eubalaena right whales, authorities have historically disagreed over whether to categorize the three populations in one, two or three species. In the days of whaling, there was thought to be a single worldwide species. Later, morphological factors such as small differences in the skull shape of northern and southern animals indicated that there were at least two species—one found only in the northern hemisphere, the other found in the Southern Ocean.^[2] Furthermore, no group of right whales has been known to swim through warm equatorial waters to make contact with the other (sub)species and (inter)breed: their thick layers of insulating blubber make it impossible for them to dissipate their internal body heat in tropical waters.

In recent years, genetic studies have provided clear evidence that the northern and southern populations have not interbred for between 3 million and 12 million years, confirming the status of the Southern Right Whale as a distinct species. More surprising, then, has been the finding that the northern hemisphere Pacific and Atlantic populations are also distinct, and that the Pacific species (now known as the North Pacific Right Whale) is in fact more closely allied with the Southern Right Whale than with the North Atlantic Right Whale. While Rice continued to list two species in his 1998 classification,^[3] this was disputed by Rosenbaum et al. in 2000.^[4] and Brownell et al (2001).^[5] In 2005, Mammal Species of the World listed three species, indicating a seemingly more permanent shift to this preference.^[1]

Three Eubalaena species theory

"Whale lice", parasitic cyamid crustaceans that live off skin debris, offer further information on Eubalaena right whale populations through their own genetic patterns. Because the lice reproduce much more quickly than whales, their genetic diversity is greater. Marine biologists at the University of Utah examined these lice genes and determined that their hosts split into three species 5–6 million years ago, and that these species were all equally abundant before whaling began in the 11th century.^[7] The communities were first split off because of the joining of North and South America. The heat of the equator then separated them further into northern and southern groups. "This puts an end to the long debate about whether there are three [Eubalaena] species of right whale. They really are separate beyond a doubt," Jon Seger, the project's leader, told BBC News.^[8]

Description

Like other right whales, Southern Right Whales are readily distinguished from other whales by the callosities on their heads, a broad back without a dorsal fin, and a long arching mouth that begins above the eye. The body of the whale is very dark grey or black, occasionally with some white patches on the belly. The right whale's callosities appear white, not due to skin pigmentation, but to large colonies of cyamids or whale lice.

Southern Right Whales are almost indistinguishable from the closely related Atlantic Northern Right Whale and the North Pacific Right Whale, with only some minor skull differences. They may have fewer callosities on their head and more on their lower lips than the northern species.^[9]

Behavior

One behavior unique to Southern Right Whales, known as sailing is that of using their elevated flukes to catch the wind. It appears to be a form of play and is commonly seen off the coast of Argentina.^[9]

Whaling

Main article: History of whaling

See also:

By 1750 the Atlantic Northern Right Whale was as good as extinct for commercial purposes and the Yankee whalers moved into the South Atlantic before the end of the 18th century. The southernmost Brazilian whaling station was established in 1796, in Imbituba. Over the next one hundred years, Yankee whaling spread into the Southern and Pacific Oceans, where the Americans were joined by fleets from several European nations.

Southern Right Whales had been coming to New Zealand waters in very large numbers before the 19th century, but were extensively hunted during the period 1820-1900. Hunting gradually wound down as the numbers of whales dwindled and all but disappeared from coastal New Zealand waters.<ref name = ""Gaskin64>Gaskin, D.E. (July 1964). "Return of the Southern Right Whale (Eubalaena australis Desm.) to New Zealand Waters, 1963". Tuatara 12 (2): 115-118. Retrieved on 2007-07-22.  The beginning of the 20th century saw much greater industrialization of whaling, and the takes grew rapidly. By 1937, there had been, according to whalers' records, 38,000 takes in the South Atlantic, 39,000 in the South Pacific, 1,300 in the Indian Ocean, and 15,000 in the north Pacific. Given the incompleteness of these records, the actual take was somewhat higher.^[10]

As it became clear that stocks were nearly depleted, a worldwide total ban on right whaling was agreed upon in 1937. The ban was largely successful, although some whaling continued in violation of the ban for several decades. Madeira took its last two right whales in 1968. Illegal whaling continued off the coast of Brazil for many years and the Imbituba land station processed right whales until 1973. The Soviet Union is now known to have illegally taken over 3,300 Southern Right Whales during the 1950s and '60s,^[11] although it only reported taking 4.^[12]

After whaling ceased in 1937, whales began to be seen again in Australian and New Zealand waters from the early 1960s.<ref name = ""Gaskin64/>

Population and distribution

Southern Right Whales spend the summer months in the far Southern Ocean feeding, probably close to Antarctica. They migrate north in winter for breeding and can be seen around the coasts of Argentina, Australia, Brazil, Chile, Mozambique, New Zealand and South Africa. The total population is estimated to be between seven and eight thousand. Since hunting of the Southern Right Whale ceased, stocks are estimated to have grown by 7% a year. It appears that the South American, South African and Australasian groups intermix very little, if at all, because the fidelity of a mother to its feeding and calving habitats is very strong. The mother also passes these instincts to her calves.^[1]

Because the oceans are so large, it is very difficult to accurately gauge the size of a whale population. The estimate of 7,000 Southern Right Whales came about following an IWC workshop held in Cape Town in March 1998. Researchers used data about adult female populations from three surveys (one in each of Argentina, South Africa and Australia collected during the 1990s) and extrapolated to include unsurveyed areas, number of males and calves using available male:female and adult:calf ratios to give an estimated 1999 figure of 7,000 animals.^[14].

In Brazil, more than 300 individuals have been cataloged through photo identification (using their distinctive head callosities) by the Brazilian Right Whale Project, maintained jointly by Petrobras (the Brazilian state-owned oil company) and the International Wildlife Coalition. The State of Santa Catarina hosts a concentration of breeding and calving right whales from June to November, and females from this population are also known to calve off Argentinian Patagonia.

Conservation

The Southern Right Whale, listed as "endangered" by CITES and "lower risk - conservation dependent" by the IUCN, is protected in the jurisdictional waters of all countries with known breeding populations (Argentina, Australia, Brazil, Chile, New Zealand, South Africa and Uruguay). In Brazil, a federal Environmental Protection Area encompassing some 1,560 km² (602 miles²)and 130 km (80 miles)of coastline in Santa Catarina State was established in 2000 to protect the species' main breeding grounds in Brazil and promote regulated whale watching.^[15]

Whale watching

See also:

Southern Right Whales have made Hermanus, South Africa one of the world centers for whale watching. During the winter months (July–October), Southern Right Whales come so close to the shoreline that visitors can watch whales from strategically-placed hotels. The town employs a "whale crier" (cf. town crier) to walk through the town announcing where whales have been seen. Southern Right Whales can also be watched at other winter breeding grounds.

In Brazil, Imbituba in Santa Catarina has been recognized as the National Right Whale Capital and holds annual Right Whale Week celebrations in September, when mothers and calves are more often seen. The old whaling station there has been converted to a museum documenting the history of right whales in Brazil. In Argentina, Península Valdés in Patagonia hosts (in winter) the largest breeding population of the species, with more than 2,000 animals catalogued by the Whale Conservation Institute and Ocean Alliance.^[16]

In Australia's winter and spring, Southern Right Whales can be seen from the Bunda Cliffs and Twin Rocks, both along the remote Great Australian Bight in South Australia.^[17]

References

Cited texts

• Carwardine MH, Hoyt E (1998). Whales, Dolphins and Porpoises. Surry Hills, NSW: Reader's Digest. ISBN 0-86449-096-8. 

External links

• Whale and Dolphin Conservation Society (WDCS)