III. MATERIALS AND METHODS 
1. Station Characteristics and Sampling Levels 
Sampling was conducted at four stations on each jetty, two located on 
opposite sides of the jetty near the outer (offshore) end and two located 
opposite one another near the inner (inshore) bend of the jetty (Fig. 1). 
This arrangement provided sampling sites on rocks which had been laid 
down at different seasons of the year, and also allowed comparisons 
between wave-exposed and sheltered sides of jetty rocks laid down at the 
same time. Table 1 provides a listing of the station designations and 
the date of rock placement at those locations. 
Six intertidal levels were sampled at each station to provide informa- 
tion on the vertical zonation of biota on the rocks. These levels were 
located at mean low water (MLW) and 0.5 m, 1.0 m, 1.5 m, 2.0 m, and 2.5m 
above MLW. With a mean tidal range of 1.4 m at Murrells Inlet (National 
Ocean Survey, 1981), these levels encompassed the entire intertidal zone 
and extended into the supratidal region near the crest of the jetty. 
Biotic zonation was less pronounced in the subtidal region, and 
stations were located at 1-m intervals below MLW. Shallow waters in the 
vicinity of the north jetty limited sampling to levels at depths of -1m 
(below MLW) on the inner transects and at -1 m and -2 m on the outer 
transects. Water was even shallower around the south jetty. No subtidal 
levels were sampled on the exposed side, and only the -l-m level could be 
sampled on the sheltered side of that jetty. All subtidal levels of both 
jetties were located at least 0.5 m above the bottom to avoid scouring 
effects due to wave-entrained sand. By the summer of 1981, additional 
shoaling had occurred around the south jetty, resulting in burial of the 
MLW and -1-m levels on the channel side (SPI) and the 0.5-m and MLW levels 
on the exposed side (SEI). Shoaling continued and by the summer of 1982, 
the 0.5-m sampling level at SPI was also buried. 
Benchmarks at known elevations above MLW were marked with paint at 
the top of each transect. Intertidal levels were located using metered 
plumb lines oriented to the benchmarks. Subtidal levels were sampled 
using scuba and were located using a float and metered line. The float 
line was adjusted to the appropriate length based on tidal height of the 
water compared to the benchmark height. 
2. Sampling Dates 
The first samples were collected at north jetty stations during July 
1979, one year after construction at the inner stations and 8 months 
after construction at the outer stations. Sampling was then repeated 
during the summer (July or August) at yearly intervals through 1982. 
The first south jetty samples were collected in May 1980, seven 
months after rock emplacement at the inner stations and three months 
after rock emplacement at the outer stations. Sampling was repeated at 
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