463
tionship between these right whale populations. Genetic studies have shown that the
Argentinean and Brazilian individuals are part of a single genetic population due to
the high gene flow among these breeding grounds (Ott 2002). However, there is also
evidence from stable isotope studies that individuals from southern Brazil are isotopically distinct from those from central Argentina which means that individuals from
the two areas exploit different feeding grounds (Vighi et al. 2014). Right whales feed
in at least four feeding grounds in the South Atlantic, whose location they learn from
their mothers (Valenzuela et al. 2009). It is suggested some degree of population substructure within the western South Atlantic right whales (Vighi et al. 2014).
The ongoing comparison with individuals cataloged in Argentina, as well as the
inclusion of individuals cataloged in Uruguay, are fundamental to the understanding
of aspects of the ecology of the species in the western South Atlantic Ocean. Photoidentification research on right whales have also been used to assess body condition
and health from an external perspective providing a tool to monitor the status of
both individual whales and the population as a whole (Rolland et al. 2009). From
the stories of individual whales one can understand the ecological needs of whales
at the population level, identify possible threats, generating invaluable information
to its conservation and management.
16.8 The Brazilian Right Whale Population
The growth rate and other demographic parameters have been estimated from the
number of whales photo-identified each year during aerial surveys off their breeding
grounds (e.g. Bannister 1990; Best et al. 2001; Cooke et al. 2001). The most recent
global estimate is 13,611 southern right whales in 2009, which means about 20% of
its pre-exploitation abundance (IWC 2013). The species is currently listed as least
concern (LC) in the IUCN Red List of Threatened Species (Reilly et al. 2013).
The recovery of right whales in Brazil was apparently slow in the first years of aerial
surveys, but a rapid increase in numbers was observed in early 2000s (Groch et al.
2005). The number of right whales off Brazil was estimated to have increased at a rate
of 14% per year up to 2003, a rate considered outside the range of biological plausibility
for a natural rate of increase for southern right whales (Best et al. 2001). A possible
explanation for the increase was immigration from other breeding grounds such as
Peninsula Valdes, Argentina, where the whale numbers have been increasing at a rate of
6.5% (Cooke et al. 2013). An update analysis for southern right whales off Brazil estimated an average 12.0% (CI 8.514.2%) rate of increase over the period 1987–2010.
Population size in 2010 was estimated at 197 mature females (CI 146–234) (IWC 2013).
With the growing numbers of right whales off Brazil it is expect the whales to
expand their range as they have off Argentina and South Africa (Best 1990; Rowntree
et al. 2001). Whaling records indicate that right whales were found up to the northeastern coast of Brazil (~16°S) (Ellis 1969). In five dedicated aerial surveys conducted along the southeast (2001, 2002, 2004 and 2008) and northeast (2001–2002)
cost of Brazil during the peak of the right whale season, 8 mother-calf pairs were
16 Conservation Advances for the Southern Right Whales in Brazil
tionship between these right whale populations. Genetic studies have shown that the
Argentinean and Brazilian individuals are part of a single genetic population due to
the high gene flow among these breeding grounds (Ott 2002). However, there is also
evidence from stable isotope studies that individuals from southern Brazil are isotopically distinct from those from central Argentina which means that individuals from
the two areas exploit different feeding grounds (Vighi et al. 2014). Right whales feed
in at least four feeding grounds in the South Atlantic, whose location they learn from
their mothers (Valenzuela et al. 2009). It is suggested some degree of population substructure within the western South Atlantic right whales (Vighi et al. 2014).
The ongoing comparison with individuals cataloged in Argentina, as well as the
inclusion of individuals cataloged in Uruguay, are fundamental to the understanding
of aspects of the ecology of the species in the western South Atlantic Ocean. Photoidentification research on right whales have also been used to assess body condition
and health from an external perspective providing a tool to monitor the status of
both individual whales and the population as a whole (Rolland et al. 2009). From
the stories of individual whales one can understand the ecological needs of whales
at the population level, identify possible threats, generating invaluable information
to its conservation and management.
16.8 The Brazilian Right Whale Population
The growth rate and other demographic parameters have been estimated from the
number of whales photo-identified each year during aerial surveys off their breeding
grounds (e.g. Bannister 1990; Best et al. 2001; Cooke et al. 2001). The most recent
global estimate is 13,611 southern right whales in 2009, which means about 20% of
its pre-exploitation abundance (IWC 2013). The species is currently listed as least
concern (LC) in the IUCN Red List of Threatened Species (Reilly et al. 2013).
The recovery of right whales in Brazil was apparently slow in the first years of aerial
surveys, but a rapid increase in numbers was observed in early 2000s (Groch et al.
2005). The number of right whales off Brazil was estimated to have increased at a rate
of 14% per year up to 2003, a rate considered outside the range of biological plausibility
for a natural rate of increase for southern right whales (Best et al. 2001). A possible
explanation for the increase was immigration from other breeding grounds such as
Peninsula Valdes, Argentina, where the whale numbers have been increasing at a rate of
6.5% (Cooke et al. 2013). An update analysis for southern right whales off Brazil estimated an average 12.0% (CI 8.514.2%) rate of increase over the period 1987–2010.
Population size in 2010 was estimated at 197 mature females (CI 146–234) (IWC 2013).
With the growing numbers of right whales off Brazil it is expect the whales to
expand their range as they have off Argentina and South Africa (Best 1990; Rowntree
et al. 2001). Whaling records indicate that right whales were found up to the northeastern coast of Brazil (~16°S) (Ellis 1969). In five dedicated aerial surveys conducted along the southeast (2001, 2002, 2004 and 2008) and northeast (2001–2002)
cost of Brazil during the peak of the right whale season, 8 mother-calf pairs were
16 Conservation Advances for the Southern Right Whales in Brazil