Evidence for transoceanic migrations by loggerhead sea turtles in the southern Pacific Ocean

Proc Biol Sci. 2009 Jun 7;276(1664):1993-9. doi: 10.1098/rspb.2008.1931. Epub 2009 Mar 4.

Abstract

Post-hatchling loggerhead turtles (Caretta caretta) in the northern Pacific and northern Atlantic Oceans undertake transoceanic developmental migrations. Similar migratory behaviour is hypothesized in the South Pacific Ocean as post-hatchling loggerhead turtles are observed in Peruvian fisheries, yet no loggerhead rookeries occur along the coast of South America. This hypothesis was supported by analyses of the size-class distribution of 123 post-hatchling turtles in the South Pacific and genetic analysis of mtDNA haplotypes of 103 nesting females in the southwest Pacific, 19 post-hatchlings stranded on the southeastern Australian beaches and 22 post-hatchlings caught by Peruvian longline fisheries. Only two haplotypes (CCP1 93% and CCP5 7%) were observed across all samples, and there were no significant differences in haplotype frequencies between the southwest Pacific rookeries and the post-hatchlings. By contrast, the predominant CCP1 haplotype is rarely observed in North Pacific rookeries and haplotype frequencies were strongly differentiated between the two regions (F(st)=0.82; p=<0.00001). These results suggest that post-hatchling loggerhead turtles emerging from the southwest Pacific rookeries are undertaking transoceanic migrations to the southeastern Pacific Ocean, thus emphasizing the need for a broader focus on juvenile mortality throughout the South Pacific to develop effective conservation strategies.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animal Migration*
  • Animals
  • DNA, Mitochondrial / chemistry
  • Female
  • Genetic Markers
  • Genetic Variation
  • Geography
  • Haplotypes
  • Pacific Ocean
  • Population Density
  • Sequence Analysis, DNA
  • Turtles / genetics
  • Turtles / physiology*
  • Water Movements

Substances

  • DNA, Mitochondrial
  • Genetic Markers