BODKIN: MACROCYSTIS AND NEREOCYSTIS KELP FORESTS 



N 



Ragged Pt. 



Pt. Sierra Nevada 



Pt. Piedras Blancas 



Figure 2 . — Location of areas sampled . Piedras 

 Blancas Pt., south, to San Simeon Pt.: kelp 

 canopies are dominated by Macrocystis pyrifera. 

 Piedras Blancas Pt. north, to Ragged Pt.: kelp 

 canopies are dominated by Nereocystis luetkeana. 

 Big Creek (not shown) is about 38 km north of 

 Ragged Pt. 



'■:■■ *&K-- 



• San Simeon 



10 km 



1982 to October 1983. Transects were apportioned 

 evenly throughout early summer to late fall in each 

 of the forest types. 



A belt transect, as described by Brock (1954) and 

 modified by Quast (1968), was used with the aid of 

 scuba to conduct subtidal fish surveys. Each survey 

 consisted of two components, benthic and midwater. 

 A 50 m fiberglass tape was extended across the 

 ocean floor in differing compass courses, extending 

 from eye bolts permanently embedded in the sub- 

 strate, or from the anchor of a dive boat on hap- 

 hazardly located transect sites. The width of the 

 midwater transect was determined by measuring 

 the horizontal water visibility 2 m above the sub- 

 strate. This was done by sighting down the transect 

 line (fiberglass tape) toward the zero end, where a 



small bicolored float (13.5 x 5.5 cm) was suspended 

 2 m off the bottom. The observer moved away from 

 the float along the line. When the float could not 

 be readily discerned, the position on the tape was 

 recorded. This value was doubled (to include obser- 

 vations on either side of the transect line) to obtain 

 the width of the midwater transect. This survey 

 technique may lead to a slight underestimation of 

 fish densities due to decreasing searching efficiency 

 with increasing distances from observer to observed 

 (Caughley 1977). Surveys were conducted only when 

 visibility exceeded 4.4 m. Horizontal water visibil- 

 ity ranged from 4.4 to 12.1 m (Macrocystis x = 

 6.6 m, SE = 2.6; Nereocystis x = 7.4 m, SE = 

 0.49). The width of the benthic survey was 4 m (2 

 m on each side of the transect tape). All sampling 



801 



