for 24 hours in a 4 percent solution of sodium hexametaphosphate 

 (Calgon) , then washed through a 0.062-millimeter screen to separate 

 the silts and clays from the sand. The sand was ovendried at 90° 

 Celsius for 12 hours, then shaken for 10 minutes in a graded 

 series of nested sieves (U.S. Standard Sieve Series) corresponding 

 to the Wentworth scale. 



Organic content was determined by ovendrying an additional 

 sediment aliquot, then measuring percent weight loss after inciner- 

 ation at 500° Celsius for 1 hour. 



Carbonate content was determined by first washing a sediment 

 sample with freshwater, drying it at 105° Celsius to constant 

 weight, then adding dilute [10 percent hydrochloric acid until all car- 

 bonates had dissolved, as indicated by the lack of carbon dioxide 

 bubbles. Samples were then washed again, dried, and weighed to the 

 nearest 0.001 gram. Carbonate content was computed as percent 

 weight loss. 



Reef stations were sampled in late March 1978 (Fig. 4) . At 

 each station, three 1 .0- square -meter areas of reef surface were 

 photographed with a Nikonos III underwater camera fitted with a 

 Honeywell 710 Strobonar flash. The areas photographed were randomly 

 selected by dropping a 1 . 0-square-meter PVC frame onto the reef from 

 an anchored boat. Kodachrome slides were later projected and ana- 

 lyzed by counting the number of epibenthic organisms belonging to 

 the more common species, using reference specimens collected from 

 the field to verify visual identifications. These quadrat analyses 

 were supplemented by frequent observation dives along both transects 

 throughout the duration of this study. 



IV. RESULTS 

 1. S ediments . 



Results of sediment analyses from all sand stations along 

 both transects are shown in Table 1. 



Particle-size distributions at the intertidal stations 

 (HS-1 and GS-1) were characterized by a high proportion (> 90 

 percent) of sand grains larger than 0.25 millimeter in diameter 

 The mean grain size at Hallandale Beach (2.30 millimeters), however, 

 was over twice that at Golden Beach (1.02 millimeters). 



Conspicuous differences between transects were also evident 

 at the shallowest subtidal stations (HS-2 and GS-2) . At Hallandale 

 Beach, particle-size distributions at HS-2 were generally similar 

 to those at HS-1, although the mean grain size at HS-2 was greater 

 (3.59 millimeters). At Golden Beach, a much larger proportion 

 (74.7 percent) of particles was within the medium to fine sand 

 category (0.5 to 0.125 millimeter), with the mean grain size only 

 0. 196 millimeter. 



At stations HS-3 and GS-3, located just within the first 

 reef line, sediments were dominated (79.9 percent and 88.3 percent, 

 respectively) by particles in the fine to very fine sand category. 



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