3.2.2 Other Kelp Forests 



Bull kelp, Nereocystis luetkeana 

 (Figure 3), occurs from near Point 

 Conception, California, to the eastern 

 Aleutian Islands, Alaska (Druehl 1970), 

 and is the most abundant surface canopy 

 kelp in California north of Santa Cruz 

 (Figure 7). Where its range overlaps with 

 Macrocystis pyrifera , the two plants can 

 occur both in separate and mixed stands 

 (Yell in et al. 1977). Another kelp, 

 A! aria fistulosa , can also form surface 

 canopies in Alaska (Druehl 1970, Dayton 

 1975). Macrocystis integrifol ia , a low 

 intertidal-shallow subtidal species, has a 

 range similar to that of the bull kelp 

 (Druehl [1970] indicates Monterey as its 

 southern limit), and may form thick 

 canopies in shallow, protected water (< 8 

 m deep; Scagel 1967). Egregia menziesii 

 (Figure 3), the feather boa kelp, occurs 

 from Baja California, Mexico to British 

 Columbia (Druehl 1970, Abbott and 

 Hollenberg 1976), and often forms a sparse 

 canopy inshore from stands of M. pyrifera . 



There are no surface canopy kelps in 

 the eastern north Pacific south of the 

 range of Macrocystis pyrifera . Members of 

 the fucalean (Phylum Phaeophyta, Order 

 Fucales) genus Sargassum may form surface 

 canopies in the shallow waters of the Gulf 

 of Mexico and the Gulf of California. 

 Species of Sargassum , especially the 

 recently introduced S_. muticum (Ambrose 

 and Nelson 1982, Deysher and Norton 1982), 

 may also form surface canopies in shallow 

 water in British Columbia-Washington 

 (Norton 1981, DeWreede 1983), and in 

 southern California, particularly in 

 protected areas around Catalina Island 

 (Ambrose and Nelson 1982). Cystoseira 

 osmundacea (Figure 3), a native fucalean, 

 occurs from Ensenada, Baja California to 

 Oregon (Abbott and Hollenberg 1976). This 

 plant has a perennial vegetative base that 

 produces long, floating, reproductive 

 fronds in spring and summer. Cystoseira 

 can occur as pure stands in shallow water, 

 and mixes with other surface canopies in 

 deeper water. It is 

 as deep as kelps, 

 usually occur at the 



Pacific is the elk kelp, Pelagophycus 

 porra (Figure 3). This huge plant 

 generally does not reach the surface; its 

 long, wide blades stream out in currents 

 just beneath the surface or, in areas 

 around Catalina Island, California, drape 

 over the bottom. Plants are most common 

 along the outer margins of Macrocystis 

 forests around the southern Channel 

 Islands and other southern California 

 islands, and along the mainland from the 

 San Benito Islands in Baja California to 

 San Diego (Dawson et al. 1960, Abbott and 

 Hollenberg 1976). These geographic 

 distributions are summarized in Figure 7. 



3.3 DISTRIBUTIONAL VARIATION AMONG SITES 



The greatest difficulty in describing 

 giant kelp forest communities is that only 

 a few sites have been studied in detail, 

 and as pointed out in Chapter 1, 

 quantitative information on abundances 

 versus depth is lacking. Thus, many of 

 the generalizations about community 

 structure and the processes that affect it 

 are, at present, preliminary, and should 

 be viewed with caution. 



Given the complexity of kelp 

 communities and the qualitative nature of 

 most descriptive data, we have chosen to 

 illustrate kelp forest variability by 

 describing a few sites that have been 

 studied in some detail. Ten sites (Figure 

 8) are examined in Sections 3.3.1 and 



Greyhound Rock' 

 Sondhill Bluff 



forests. 



generally not found 



and mixed canopies 



inner edge of kelp 



Granife 

 Creek 



The only other kelp that can form a Figure 8. Location of the 

 surface canopy in the eastern north forests described in Chapter 3. 



ten kelp 



23 



