in Nova Scotia was proposed by Mann and 

 his co-workers (Mann 1973, Breen and Mann 

 1976; but see Pringle et al. [1980] for 

 alternative views). 



Kelp forests are also a source of 

 organisms for commercial collectors who 

 sell plants and animals for educational 

 and research use. The number of organisms 

 removed is probably insignificant relative 

 to commercial and sport fisheries, and 

 most are otherwise not harvested for food 

 by anyone. 



6.2.3 Habitat Use 



Commercial and recreational boat 

 traffic often goes through giant kelp 

 forests, and gaps or channels through 

 canopies, created by propellers cutting 

 surface fronds, are common where traffic 

 is heavy. Occasional small strips are cut 

 by light boat traffic. Heavy traffic may 

 cause a reduction in adult giant kelp 

 density, and an increase in juvenile kelp 

 and understory red algae (North 1957). 

 Small strips probably fill in again by 

 vegetative growth. Except where channels 

 are produced, drivers of small boats 

 generally avoid kelp canopies as the cut 

 fronds easily foul propellers and water 

 intakes of engines. 



Various pipelines, particularly from 

 offshore tanker facilities, are placed 

 through kelp forests. The pipe and any 

 covering structures, however, are usually 

 soon covered with organisms including 

 kelp, and probably have little long-term 

 impacts. Short-term effects include 

 damage to organisms in the path of the 

 pipeline, and possible increased turbidity 

 and sedimentation during construction. 



A highly probable future use of giant 

 kelp forest habitat is for mariculture 

 facilities. Various research programs 

 currently use kelp forests to test poten- 

 tial culture techniques, and one lease has 

 been given to grow Gel idium robustum (see 

 Plants above). Giant kelp forests are 

 good potential sites for abalone culture. 

 With declining natural stocks and heavy 

 predation by man and sea otters (see Aba- 

 lone above), a profitable technique may be 

 to place juvenile abalone in structures 

 that encourage algal drift accumulation 



but discourage predation, and then place 

 these structures within giant kelp 

 forests. 



6.3 RECREATIONAL USE 



6.3.1 Sport Fishing 



Kelp forests are favored areas for 

 hook-and-line and spear fishing, and sport 

 divers harvest lobsters, crabs, scallops, 

 and abalone by hand. The extent of this 

 fishing and possible effects on popula- 

 tions are largely unknown as use and 

 catches are not reported. Miller and 

 Geibel (1973) reported a 540% increase in 

 sport diver activity from Pismo Beach 

 (near San Luis Obispo) to the Oregon 

 border between 1960 and 1972. There are 

 thousands of divers and sport fishermen in 

 California, and they are a common sight in 

 kelp forests throughout the State when 

 weather conditions are favorable. Numer- 

 ous charter boats provide diver transport 

 to offshore islands, especially Santa 

 Catalina Island off Los Angeles. Divers 

 occasionally take non-game species as 

 curios. This is illegal, however, in 

 California without a scientific collecting 

 permit. 



6.3.2 Other Recreational Activities 



Numerous divers use giant kelp for- 

 ests for underwater photography or simply 

 enjoyment, without any fishing. Non- 

 divers visit the coast to observe surface 

 organisms from shore or in tour boats; sea 

 otters are a special attraction in central 

 Cal ifornia. 



6.3.3 Governmentally Regulated Areas 



Many levels of government have estab- 

 lished a variety of special use areas 

 along the California coast, and some of 

 these areas have been established because 

 of their proximity to giant kelp forests. 

 In addition to city and county parks, the 

 State has an extensive park system where 

 fishing, collecting, and other uses of 

 nearshore habitats are more highly regu- 

 lated. State reserves such as the one at 

 Point Lobos near Carmel also regulate 

 public access, and in addition, further 

 restrict fishing, collecting, and even 

 observational sport diving. Miller and 

 Geibel (1973) pointed out the value of 



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