Grigg et al.: Spatial and seasonal relationships between Phoca vitulma richardii and their prey 
371 
Finally, this spatially explicit approach to the identi- 
fication of foraging areas has applications to manage- 
ment of pinnipeds in other areas, and other marine 
predators that can be tracked with satellite telemetry. 
With local data inputs comparable to those used in 
this study, this approach could be applied to manage- 
ment of marine predators in other areas. Knowledge 
of the location of foraging areas is important to such 
management concerns as the potential effects of future 
shifts in the spatiotemporal distribution of prey (due to 
climate change, etc.), the link between local resource 
availability and local population trends, prediction of 
possible interactions of marine predators with fisher- 
ies, or identification of appropriate locations for marine 
protected areas. 
Acknowledgments 
We would like to thank the following individuals: C. 
Morton and his colleagues at the California Depart- 
ment of Transportation (Caltrans); J. Harvey and his 
students; F. Gulland; D. Greig; J. Neale; T. Garfield; 
R. Larson; K. Hieb; D. Kopec; S. Oates; and J. Grigg. 
We would particularly like to thank the students and 
staff at San Francisco State University (SFSU) who 
helped with this study. This project was supported by 
Caltrans, SFSU, and a University of California Grant to 
E.K.G. The research was conducted in accordance with 
Incidental Harassment Authorizations fr23de97-52 and 
frl4ja00-38 issued by the National Marine Fisheries 
Service (NMFS) to Caltrans, NMFS scientific research 
permit no. 373-1575, and SFSU Animal Care and Use 
Committee permit no. #99-534. 
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