342 



Fishery Bulletin 105(3) 



+1 



1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2UU3 



Year 



Figure 3 



Estimated leatherback turtle (Dermochelys coriacea) abundance within the California 

 study area, with and without ^(0) correction for diving behavior. Error bars indicate one 

 standard error (SE); NS indicates no surveys were conducted during that year. 



including all ten survey years; P=0.04 for only the 

 seven coastwide survey years). 



Discussion 



The results of this study demonstrate the importance 

 of neritic waters off California to foraging leatherback 

 turtles and provide the first estimates of abundance for 

 a Pacific foraging population of this critically endangered 



species. The aerial line-transect surveys, although not 

 originally designed to census this species, provided quan- 

 titative data during the summer and fall peak season of 

 occurrence (Starbird et al., 1993). Absolute abundances 

 of foraging Pacific leatherback turtles were estimated 

 for the first time by applying a new telemetry-based 

 correction factor to account for submerged animals. Cor- 

 rected densities in this study were 2.1 times greater than 

 uncorrected densities. This contrasts markedly with the 

 correction factor of 7.6 derived from dive data for a single 

 leatherback turtle off St. Croix, U.S. Virgin Islands 



