4. Benthlc Fauna . 



a. Field Procedures . Benthic fauna was sampled with a stainless-steel 

 plug sampler (Fig. 3) covering a surface area of 0.016 square meter and 

 penetrating to a depth of 23 centimeters. This was the same type coring 

 device used by Saloman (1976). The top of the core was covered with 0.5- 

 square millimeter mesh, stainless-steel screen to prevent loss of organisms. 

 In operation the sampler is inserted into the substratum; the sediments on 

 the outside of one side of the sampler are removed, and the sampler tilted 

 and lifted out with a hand covering the bottom. At stations with a water 

 depth greater than 1.2 meters the sampler is operated by a diver who 

 removes the core, inverts i:, and places it in a metal basket. When four 

 cores are obtained, the basket is hauled to the surface vessel, where the 

 samples are extruded into labeled 5-gallon (19 liters) plastic buckets. 

 Samples taken in less than 1.2-meter depths are obtained by wading and 

 returning to the beach for processing. 



Five plug samplers were taken at each station: four samples for 

 faunal analysis and one as a backup in case of a loss of a processed sample. 

 Onshore the samples were washed through a box sieve with a mesh of 0.701 

 square millimeter. The material retained on the sieve was placed in a 

 plastic jar with both internal and external labels. A 10 to 15 percent 

 solution of magnesium chloride in seawater was added to the jars to relax 

 the organisms in order to reduce fragmentation upon preservation. After 

 relaxation, a 10 percent formalin-seawater buffered solution containing 

 rose bengal stain (to facilitate sorting) was added to the samples. 

 Samples were transferred to 70 percent isopropyl alcohol within a week of 

 initial preservation. 



b . Laboratory Procedures , in the laboratory faunal samples were sorted 

 under a stereozoom binocular dissecting microscope. Taxonomic identifica- 

 tions were performed under the binocular dissecting scope or a binocular 

 compound microscope. Identifications of species were accomplished with 

 the use of descriptiv,-^. literature and a set of reference specimens from 

 Saloman (1976) . Additionally, taxonomic experts were utilized to either 

 identify or confirm identifications of selected taxa. 



c. Data Analysis Procedures . Numerical indices were chosen which 

 have a widespread use in scientific literature and provide summaries of 

 data, and which would aid comparisons with Saloman's (1976) data. 



Faunal density estimates are reported as numbers of individuals per 

 square meter. Values were computed by dividing the total number of 

 individuals found at a station (for four replicates) by the total area 

 sampled (0.0624 square meter). 



Species richness was considered to be the total number of species 

 found at each station for all replicates. 



16 



