3.2 DISTRIBUTION ALONG THE PACIFIC COAST 

 OF NORTH AMERICA 



3.2.1 Giant Kelp Forests 



Stands of Macrocystis pyrifera occur 

 as far north as Ano Nuevo Island, approxi- 

 mately 30 km north of Santa Cruz in 

 central California (North 1971b, Druehl 

 1970; Foster pers. obs. ; Figure 7). The 

 species does not occur in Oregon (Phinney 

 1977) or British Columbia (Scagel 1967). 

 Stands can occur as far south as Punta 

 Asuncion-Punta San Hipolito in Baja 

 California, Mexico (27°N lat. ; Dawson 



1951, North 1971b), but this southern 

 limit varies. Estes (pers. comm. ) 

 reported that as of the summer of 1984, 

 the most southerly plants were around the 

 San Benito Islands, over 240 km north-west 

 of Punta Asuncion-Punta San Hipolito. This 

 probably reflects the effects of storms 

 and changes in water characteristics 

 associated with the recent "El Nino" (see 

 Chapter 3). In California, giant kelp 

 canopies occupy an area of about 110 

 km 2 (Miller and Geibel 1973), although this 

 is highly variable between seasons and 

 years (see Section 3.5). 



Figure 7. The distribution of algae that form surface canopies in the northeast 

 Pacific (redrawn from Druehl 1970). 



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