illustrates the number of taxa on transects 1 and 2. The species 

 diversity increased with a linear distance to about 108 - 120m. On 

 transect 2 the greatest number of species was found between 45 - 117m. 

 A maximum of 24 taxa were recorded at 108m; thereafter, the species 

 numbers decreased rapidly. Transect 1 showed a relatively uniform 

 distribution between 75 - 165m. A maximum of 15 species were recorded 

 at 120m, while 8 were still evident at 180m. Thirteen species found 

 on transect 2 (Dictyota linearis , Acetabularia crenulata , Chaetomorpha 

 linum , Penicillus capitatus , Corallina cubensis , Cottonlella arcuata . 

 Griff ithsia globulif era , Hildenbrandia prototypus , Hypoglossum 

 tenuifolium , Lithothanmium sp., Lithophyllum sp,, Wrightiella 

 tumanowiczi and Wurdemannia miniata ) were not found on transect 1. 

 Three species found on transect 1 (Caulerpa ashmeadi , Caulerpa 

 cuppressoides , and Spyridia filamentosa ) were absent on transect 2. A 

 comparison of the frequency calculations for the more common species 

 on both transects shows that they are very similar. 



Many of the species which had the widest distributions (i.e., the 

 greatest frequencies of occurrence) on both transects also showed the 

 highest percent coverage. In addition, many of the commonest species 

 on both transects also showed comparable percent coverages (e.g., 

 Pocockiella variegata , Anadyomene stellata , Avrainvillea nigricans , 

 Caulerpa taxifolia , Halimeda incrassata , Udotea conglutinata , Udotea 

 cyathif ormis , Valonia ventricosa and ^ringodium f iliforme ) . However , 

 other species (e.g., Chondria dasyphylla , Cottoniella arcuata , Jania 

 sp. , Wrangelia penicillata , Dictyota bartayresii and blue-green-a) 

 showed obvious differences between the two transects . It should be 

 noted that many of the latter species are microscopic. A comparison 

 of the average percent coverage of each species for both the total 

 number of quadrants evaluated and for each quadrant occupied indicates 

 that many species had localized distributions on each transect. Such 

 differences are reflected in variations in species composition on the 

 two transects. 



Transect 2 was much less productive than 1 (Figure 6). The biomass 

 on transect 2 increased with linear distance from the reef to 60m, 

 where a maximxim of 252g/.6m^ was recorded. Beyond 60m the biomass 

 fluctuated greatly, but there was a significant reduction towards 180m 

 at which point only 10g/.6m2 was found. Transect 1 showed a sub- 

 stantial increase in biomass with linear distance to 105m, where 

 468g/.6m2 was recorded. Beyond 105m the biomass decreased rapidly to 

 55g/.6m^ at 180m. A comparison of Figures 5 and 6 indicates that there 

 is no clear-cut correlation between productivity and species diversity, 

 for peak populations of species were not always associated with high 

 values of biomass. In addition, even though transect 2 had more species 

 than transect 1, it was not as productive. It should be noted that 

 many species which were restricted to transect 2 were either micro- 

 scopic or small, crustose forms. Pocockiella variegata , Anadyomene 

 stellata , Avrainvillea nigricans , Halimeda incrassata and Udotea 

 conglutinata were the major contributors of biomass in the most 



VI-115 



