Great White Sharks
Autopsy verifies killer was great white shark
Solana Beach (north of San Diego), April, 2008 - http://www.signonsandiego.com/news/northcounty/20080429-9999-1m29sharks.html
"Collier's research shows that, historically, shark sightings and attacks are most prevalent during August, September and October."
Migration and habitat of white sharks (Carcharodon carcharias)in the eastern Pacific Ocean
http://www.topp.org/sites/topp.org/files/topp/publications/whitesharkwengetal.pdf - published 24 May 2007
Kevin C. Weng, Andre M. Boustany, Peter Pyle, Scot D. Anderson, Adam Brown, Barbara A. Block
Sharks more active on CA coast during autumn and winter. Some migrate out of the area Nov-March.
"While near pinniped rookeries in autumn and winter, sharks avoided the surface and used water to 50 m depth, consistent with a silhouettebased hunting strategy. Offshore migrations were initiated during November–March and followed periods of decreasing pinniped abundance…remained there for up to 167 days during spring and summer…. Sharks traveling to Hawaii remained near the islands up to 122 days…."
Seals
"In California [Harbor Seal] breeding occurs from March to May, and pupping between April and May depending on local populations." - Wikipedia
"Harbor seals spend their entire lives along the same stretch of coastline." - http://www.dfg.ca.gov/viewing/seals.html - By Bob Garrison, Outdoor California — May/June, 1994
Monterey Bay National Marine Sancutary Site
http://montereybay.noaa.gov/sitechar/mamm2.html
California Sea Lion
"Most individuals of this species breed on the Channel Islands off southern California and off Baja and mainland Mexico (Odell 1981), although a few pups have been born on Año Nuevo Island (Keith et al. 1984.). Individuals, primarily males, are therefore most common in the MBNMS during fall and spring migrations between southern breeding areas and northern feeding areas (Orr and Poulter 1965, Peterson and Bartholomew 1967, Nicholson 1986;Figure 2)."
"The greatest concentration of California sea lions in the MBNMS occur on Año Nuevo Island and Monterey breakwater."
Steller Sea Lion
"Año Nuevo Island is the southernmost breeding area for this species, and they are rarely seen at other haul-out sites in the MBNMS."
Principal haul-out and rookery sites for four species of pinnipeds in the MBNMS
= elephant seal rookeries, 
= haul-out sites for harbor seals > 100 animals
= California sea lion haul-out sites, 
= Steller sea lion haul-out sites
Ano Nuevo
http://www.parks.ca.gov/?page_id=1115
Elephant Seals are at Ano Nuevo from December - End of April
"The elephant seal breeding season begins at Año Nuevo in December…."
"In late December, the females begin to arrive…. Three to six days after she arrives, the female gives birth to the pup…."
"By mid-March, most of the adult seals are gone, leaving the pups behind."
"…the weaned pups…during the last three weeks of April…go to sea one by one and disperse northwestward."
Harbor Seals (Phoca vitulina, year round) and Sea Lions (August - October, also Spring Migration)
"Año Nuevo Island and the adjacent mainland beaches make up one of the most important pinniped rookery and resting areas in central and northern California. (Pinnipeds are animals with finlike feet or flippers.) …. Two kinds of sea lions are…present: Steller and California. The tawny brown or yellowish Steller sea lions, which mate on the rocks around the island from mid August, are most often seen on the rocky outer portions of the island. Dark brown California sea lions do not breed at Año Nuevo, but hundreds of them, mostly males, visit the island in September and October, when they use it as a resting place on their annual feeding migration northward from rookeries in Mexico….
Harbor seals [Phoca vitulina] live on the island all year and breed there in April and May….."
