184
7.3.5 Olive Ridley, Lepidochelys olivacea
The olive ridley sea turtle is widespread on tropical and subtropical oceans and is
considered the most abundant sea turtle. In the Atlantic Ocean, this species has limited distribution and nesting has been reported mainly in Guinea Bissau, Suriname,
French Guiana and northeastern Brazil. Hahn et al. (2012) characterized the genetic
diversity and population structure of the olive ridley nesting populations in the
Brazilian coast based on 92 samples sequenced for the mtDNA control region and
67 samples genotyped for 15 microsatellite loci. Although three mtDNA haplotypes
were found, two previously unknown but very rare, the Brazilian nesting population
presented one of the lowest mtDNA diversity known for the species. mtDNA data
indicated a population expansion following a population decline in the past while
microsatellite data suggested a scenario of demographic stability, supporting the
scenario of colonization of Atlantic Ocean via a founder effect. Since this data could
not find significant genetic differences between the studied olive ridleys nesting
areas in the Brazilian coast, conservation strategies should consider the Brazilian
olive ridleys as a single interbreeding population. (Hahn et al. 2012).
Fig. 7.15 Approximate location of sampling sites along the Brazilian coast (RS—Rio Grande do
Sul State, SC—Santa Catarina State, PR—Paraná State, SP—São Paulo State, RJ—Rio de Janeiro
State, ES—Espírito Santo State, and BA—Bahia State) and geographic coordinates for six sampling sites of pelagic (stranded/incidentally caught) animals (Adapted from Vargas et al. 2008)
M.Â. Marcovaldi et al.
7.3.5 Olive Ridley, Lepidochelys olivacea
The olive ridley sea turtle is widespread on tropical and subtropical oceans and is
considered the most abundant sea turtle. In the Atlantic Ocean, this species has limited distribution and nesting has been reported mainly in Guinea Bissau, Suriname,
French Guiana and northeastern Brazil. Hahn et al. (2012) characterized the genetic
diversity and population structure of the olive ridley nesting populations in the
Brazilian coast based on 92 samples sequenced for the mtDNA control region and
67 samples genotyped for 15 microsatellite loci. Although three mtDNA haplotypes
were found, two previously unknown but very rare, the Brazilian nesting population
presented one of the lowest mtDNA diversity known for the species. mtDNA data
indicated a population expansion following a population decline in the past while
microsatellite data suggested a scenario of demographic stability, supporting the
scenario of colonization of Atlantic Ocean via a founder effect. Since this data could
not find significant genetic differences between the studied olive ridleys nesting
areas in the Brazilian coast, conservation strategies should consider the Brazilian
olive ridleys as a single interbreeding population. (Hahn et al. 2012).
Fig. 7.15 Approximate location of sampling sites along the Brazilian coast (RS—Rio Grande do
Sul State, SC—Santa Catarina State, PR—Paraná State, SP—São Paulo State, RJ—Rio de Janeiro
State, ES—Espírito Santo State, and BA—Bahia State) and geographic coordinates for six sampling sites of pelagic (stranded/incidentally caught) animals (Adapted from Vargas et al. 2008)
M.Â. Marcovaldi et al.