scholarly journals Stranding events of southern right whales, Eubalaena australis, in southern Brazil

2020 ◽  
pp. 157-160
Author(s):  
Antonio B. Greig ◽  
Eduardo R. Secchi ◽  
Alexandre N. Zerbini ◽  
Luciano Dalla Rosa

Although international protection has been granted since 1935, southern right whales have only recently shown signs of recovery, possiblydue to anthropogenic factors. Off Brazil, illegal hunting of right whales occurred until 1973. This paper reports on surveys conducted alongthe southern Brazilian coast and the information recovered on right whale strandings for this area from 1977-1995. In the first 10 years ofthis period only four cases were registered. However, in contrast, 20 cases were counted during the last nine years. These results arediscussed in relation to marine traffic and the fisheries in the area that produce risks of collision and entanglement. Further, the possibilityof storm surges being a preponderant factor in the mortalities in this area is presented. These yearly rates are compared with neighbouringareas that are also inhabited by the right whales. Both possibilities fit the hypothesis that the right whales using the Brazilian coast forbreeding may finally be showing signs of recovery.

Polar Record ◽  
1988 ◽  
Vol 24 (148) ◽  
pp. 15-20 ◽  
Author(s):  
Gregory S. Stone ◽  
William M. Hamner

AbstractDuring surveys conducted 2–20 April 1986 in Gerlache Strait, Antarctic Peninsula, 103 humpback whales Megaptera novaeangliae and eight right whales Eubalaena australis were sighted. The right whale sightings extend the southern limit of known distribution for the species. Humpback and right whale densities were respectively 0.22 (sd 0.23) and 0.01 (sd 0.06) whales per survey mile. Highest densities for both species were recorded inside bays, rather than in the relatively open water of Gerlache Strait. Both species were feeding on Antarctic krill Euphausia superba. Twenty-three humpback and four right whales were identified individually using photographs of natural features. Also included are sighting records of 18 southern bottlenose whales Hyperoodon planifrons.


2020 ◽  
pp. 125-132 ◽  
Author(s):  
J. G. Cooke ◽  
V. J. Rowntree ◽  
R. Payne

Photographs of the right whales which occur between June and December in the waters surrounding Pen´ınsula Vald´es, Argentina, have been obtained from aerial surveys conducted each year from 1971 to the present. Resightings of previously catalogued individuals enable various demographic parameters to be estimated. From analyses of multiple resightings of females accompanied by calves, estimates of the following demographic parameters were obtained, based on the data collected during 1971-90: mean calving interval 3.35 yrs (SE = 0.05 yrs); mean age at first calving 9.1 yr (SE = 0.3 yr); adult female annual mortality rate 0.019 (SE = 0.005); annual percentage rate of population increase 6.9% (SE = 0.7%); reproductive female population size in 1990: 328 animals (SE = 21). No evidence of any trend with time in mean calving interval, mortality rate or rate of population increase was found.


2009 ◽  
Vol 89 (5) ◽  
pp. 1003-1007 ◽  
Author(s):  
Larissa Rosa de Oliveira ◽  
Paulo Henrique Ott ◽  
Paulo A.C. Flores ◽  
Salvatore Siciliano ◽  
Raquel Santos de Almeida ◽  
...  

The southern right whale (Eubalaena australis) was one of the most intensively hunted whales between the 17th and 20th centuries in the southern hemisphere. Recent estimates indicate that today there are around 7000 whales, representing 5 to 10% of its original population. On the other hand, recent studies estimated that the population that migrates to the Brazilian coast grew by 14% from 1987 to 2003. However, there is no information about sex-ratio for adults or for calves in this region, which is an important parameter for understanding the biology of the species. We present here the first estimate of calves' sex-ratio of southern right whales found along the southern Brazilian coast, one of the most important wintering grounds for the species. Sex was molecularly indentified for 21 biopsies collected from calves between 1998 and 2002, along the coast of Rio Grande do Sul and Santa Catarina States, in southern Brazil. The sex-ratio was two females for one male, however, it was not statistically different (χ2 test, α = 0.05; df = 1) from the expected ratio of 1:1. This result is in accordance with the sex-ratio estimated for the species of all ages using external morphology (and behaviour information), as well as for most species of baleen whales.


Mammalia ◽  
2017 ◽  
Vol 81 (3) ◽  
Author(s):  
Daniel Danilewicz ◽  
Ignacio B. Moreno ◽  
Maurício Tavares ◽  
Federico Sucunza

AbstractThe southern right whale (SRW),


2020 ◽  
Vol 41 ◽  
pp. 373-383
Author(s):  
K Stamation ◽  
M Watson ◽  
P Moloney ◽  
C Charlton ◽  
J Bannister

In Australian waters, southern right whales Eubalaena australis form 2 genetically distinct populations that have shown contrasting patterns of recovery since whaling ceased: a western population in South Australia and Western Australia and an eastern population in southeastern Australia (Tasmania, Victoria and New South Wales). Here, we provide an abundance estimate derived from a breeding female superpopulation mark-recapture model for the southeastern southern right whale population. The population comprises 268 individuals (68 breeding females) and has increased at a rate of 4.7% per annum between 1996 and 2017. There has been no significant change in the annual abundance of mother-calf pairs sighted at the only calving ground (Logans Beach in Victoria) over the last 3 decades. The total number of southern right whales (i.e. all adults and calves) using the southeastern Australian coastline has increased by 7% since 1985. Unlike the population estimate (which was restricted to breeding females sighted prior to the post-breeding southward migration), this estimate is likely to include transiting whales from the southwestern population. The theoretical population model predicts 19 breeding females at Logans Beach in 2018 and 28 in 2028; the actual number of breeding females, as of 2018, is 14. This study provides the first complete estimate of population size and rate of increase of southern right whales along the southeastern Australian coastline. This knowledge is critical for assessing population status and recovery of southern right whales in Australia. It provides a basis for monitoring persistence and responses of the population to environmental stressors.


2020 ◽  
pp. 153-156
Author(s):  
Marcos César De Oliveira Santo ◽  
Salvatore Siciliano ◽  
Shirley Pacheco de Souza ◽  
Jose Luis Altmayer Pizzorno

This paper reports on the occurrence of southern right whales (Eubalaena australis) in southeastern Brazilian waters (18°S-25°S), withevidence of their use of the region as an important calving area. Only in recent years have right whale sightings and strandings been reportedregularly within the surveyed area. Of 71 distinct sightings reported since 1936, 39 (54.9%) were mother-calf pairs observed close to theshore. Most of these sightings (91.5%) were reported from early July to late October. Eight confirmed strandings of this species wereobserved within the surveyed area, six of which were between July and October. Stranded calves represented 62.5% of these records. Twocalves showed evidence of incidental capture. The increasing number of sightings, and recent reports of stranded calves and one adultfemale could be indicative of an increase in cetacean research efforts in the region. However, it also suggests use of the southeasternBrazilian coast as an important right whale calving area.


Author(s):  
Liliane Lodi ◽  
Marcelo Tardelli Rodrigues

Between 1993 and 2005, 68 sightings of southern right whales were recorded along 400 km of coastline between Paraty Bay (23°13'S 44°42'W) and Macaé (22°22'S 41°47'W), Rio de Janeiro State, south-eastern Brazilian coast. Mother/calf pairs represented 66.1% of sightings. Only solitary individuals showed a distinct pattern of occurrence. Females with calf did not show a distinct pattern of occurrence suggesting their widespread distribution in the area. Analysis of the records and detailed accounts of the sightings of southern right whales reveal that there exist conflicts between the animals and human activities such as harassment and collision with boats during attempted rescues, accidental entanglement in fishing nets and intentional mortality, which may have a bearing in the conservation of the species in Brazilian waters.


2020 ◽  
pp. 171-176
Author(s):  
Peter B. Best ◽  
Victor M. Peddemors ◽  
Victor G. Cockcroft ◽  
Nan Rice

Between 1963 and 1998, 55 mortalities of southern right whales and a further three ‘possible right whale’ mortalities were recorded on theSouth African coastline. Of the known right whale mortalities, 31 could be classified as ‘calves of the year’, 8 as juveniles and 14 as adults.Relatively few (6.5-16.1%) of the calf mortalities could be attributed to anthropogenic factors, compared to juveniles (25-50%) and adults(35.7-57.1%). Apparent causes of death included ship strikes (4 definite, 7 possible) and entanglement (4 definite, 1 possible), with oneharpooning incident. Five non-fatal ship strikes and 16 instances of non-fatal entanglement were also recorded. Whilst the gear mostcommonly involved in non-fatal entanglement was crayfish trap lines, three of the four entanglement fatalities involved longline gear. Theincidence of scars attributable to previous entanglement remained constant amongst mature females from 1979-1997, at 3-4%. Recordedmortalities increased over the period 1963-1997 at a rate no different from that of population growth over the same period. The current levelof anthropogenic mortality does not seem to be affecting population recovery.


2003 ◽  
Vol 9 (3) ◽  
pp. 228 ◽  
Author(s):  
Simon Allen ◽  
Lars Bejder

Southern Right Whales Eubalaena australis are an endangered species that have been recovering from unsustainable whaling practices and, despite being reported along the east and west coasts of Australia, they have not been duly accounted for in recent risk assessments for marine development. This review of the last decade of sightings highlights northerly movements into temperate and sub-tropical waters, indicates that fatal entanglement has occurred and points toward an increasing likelihood of interactions between migrating whales and inshore marine development. Given that entanglements and vessel strike are preventing the recovery of North Atlantic Right Whales Eubalaena glacialis, we recommend a precautionary approach to risk assessment around Australia and the formation of a national animal entanglement committee with both a pre-emptive role in assessing coastal development applications and a reactive role in the event of entanglement.


Sign in / Sign up

Export Citation Format

Share Document