(7) The series of triangles was then placed in perspective by con- 

 verting the distance between measurements (d^) to a distance 

 0.71 times d^. The 0.71 conversion allowed a three-dimensional 

 depiction o£ these triangles scaled to the total side of the 

 island. (0.71 = sin of a right triangle = 1/^^) 



2. Permanent Transects Seasonal Data Analysis Methods . 



The master species list for the seasonal surveys included 250 

 taxonoraic categories (70 were marine algae and 180 were marine in- 

 vertebrate taxa) . From this master list 24 taxa of marine algae and 

 30 taxa of invertebrates were selected for special study of seasonal 

 variability. Proportionately, more algal taxa were used than in- 

 vertebrate taxa, because seasonal effects are often well pronounced 

 among algae, especially reds (Rhodophijta) . The only algal taxa 

 omitted from the analysis were those of uncertain identity or which 

 (a) occurred in low density, and (b) were found on only one side and 

 during only one season. The number of invertebrate taxa selected for 

 analysis was in part dictated by data-handling considerations. Even 

 when unidentified taxa were eliminated, the amount of data remaining 

 was formidable. Many of these taxa were observed at such low fre- 

 quencies as to be of little value in any seasonal analysis. Either 

 these species are uncommon on the island; the transects missed their 

 centers of abundance; or, if they were seasonally abundant, their 

 peaks in abundance did not overlap the sampling periods. Many taxa 

 were observed only once (i.e., in only one quadrat). It is assumed 

 that most if not all of the singular-occurrence taxa and most of the 

 low-frequency taxa were generally uncommon on the island. Observa- 

 tions elsewhere on the island during other times of the year (i.e., 

 during reconnaissance diving, measurement of boundaries of associa- 

 tions, and biomass measurements) tend to corroborate this. For these 

 reasons, these rarely encountered taxa were excluded from the sea- 

 sonal analysis. 



70 



