blackbirds ( Auphaqus cyanocephalus ) dig 

 through beach-cast wrack in search of 

 marine invertebrates and insects, and the 

 latter also catch beach flies. Beds of 

 decomposing kelp along central and 

 southern California beaches attract black 

 phoebes ( Sayarnis nigricans ) , house 

 sparrows ( Passer " demesticus ) , and 

 yellow-rumped warblers ( "Dendrioca 

 coronata ) that feed on flies and other 

 insects (Davis and Baldridge 1980). 



Jameson (pers. comm. ) also observed a 

 variety of birds feeding on 

 drift-associated invertebrates, and in the 

 case of physically unstable cobble 

 beaches, he pointed out that this drift 

 can change an otherwise food-poor habitat 

 into a rich feeding area for birds. He 

 noted intense nearshore feeding by gulls 

 around partially decomposed drift when the 

 drift is moved back into the water during 

 high tides or storms, and suggests that 

 the gulls may be eating amphipods exposed 

 when the drift breaks up. 



Ainley (1976) states that "...marine 

 biologists as a general rule ignore 

 birds." This viewpoint is confirmed in 

 the case of bird-kelp interactions and, as 

 further indicated by the considerable 

 speculation in this section of the 

 profile, much remains to be learned about 

 the relationship between kelp forests and 

 nearshore bird populations. 



4.6.2 Marine Mammals 



4.6.2.1 Introduction . The sea ot- 

 ter, gray whale, killer whale, harbor 

 seal, and California sea lion (Figure 24) 

 are listed (North 1971a) as the mammals 

 associated with the kelp forests of south- 

 ern California and northern Baja Cali- 

 fornia, Mexico, although the sea otter 

 does not presently occur south of Point 

 Conception (Figure 8). All of these 

 mammals do occur associated with 

 Macrocystis pyri fera and Nereocystis 

 luetkeana along the central California 

 coast. 



The sea otter ( En hydra lutris ) 

 exhibits the closest association with kelp 

 forests, potentially inhabiting the kelp 

 surface canopy and foraging throughout the 

 water column during its entire life. Gray 

 whales (Eschrichtius robustus) are 



Gray Whale 



Killer Whale 



Figure 24. Marine mammals associated with 

 kelp forests. 



commonly seen offshore from kelp forests 

 during their migrations along the coast, 

 and have been observed to feed on mysid 

 shrimp associated with the kelp. The 

 relationship of California sea lions 

 ( Zalophus cal ifornianus ) and killer 

 whales ( Orcinas orca ) to kelp forests is 

 probably limited to transitory foraging 

 excursions in the kelp. Harbor seals 

 ( Phoca vitul ina ) are frequently seen in 

 kelp forests and feed on a variety of kelp 

 forest fishes. 



The size of gray whale and sea otter 

 populations in the northeast Pacific was 

 drastically reduced by the early part of 

 this century due to human exploitation. 

 Historical accounts of the aboriginal and 

 commercial exploitation of sea otters can 

 be found in Kenyon (1969); those of gray 

 whales in Rice and Wolman (1971). 

 Enactment of protective legislation for 

 otters in 1911, and for gray whales in 

 1972, has been instrumental in the 

 dramatic recovery of both populations. As 

 these animals have increased in numbers 

 and begun to inhabit portions of their 

 ancestral range, their respective roles in 

 the ecology of the kelp forest community, 

 particularly that of the sea otter, are 

 being elucidated. 



4.6.2.2 Sea otter (Enhydra lutris) . 

 In California, the preferred habitat of 

 the sea otter is a lush kelp canopy in 

 proximity to rocky substrata with deep 

 crevices (Woodhouse et al. 1977). Kelp 

 forests dampen wave action, creating areas 

 of calm that serve as otter refuges from 



80 



