FL (Searles 1984). Because natural hard 

 substrates are rare in the bight, most 

 seaweeds are attached to shell fragments, 

 other algae, seagrasses, or to introduced 

 substrates such as seawalls, jetties, and 

 docks. 



Between Long Island Sound and Cape 

 Hatteras, there are approximately 150 

 species of red (Rhodophyta) , brown 

 (Phaeophyta) , and green (Chi orophyta) 

 seaweeds (Searles 1984). Between Cape 

 Hatteras and Cape Canaveral , there are 

 approximately 320 species; 303 of these 

 are known from North Carolina (Searles 

 1984). Ninety-five species occur in South 

 Carolina (Wiseman and Schneider 1976; 

 Wiseman 1978; Blair and Hall 1981), 81 

 species occur in Georgia (Chapman 1971, 

 1973; Searles 1981, 1984), and only 43 are 

 reported in Florida north of Cape 

 Canaveral (Humm 1952). However, Humm 

 (1952) probably underestimates the number 

 of species in the area since 234 species 

 occur between Cape Canaveral and Palm 

 Beach (Kerr 1976; Eiseman 1976, 1979; 

 Eiseman and Moe 1981; Eiseman and Norris 

 1981; Hall and Eiseman 1981). There are 

 several reasons why North Carolina appears 

 to have 3 to 4 times the number of seaweed 

 species as South Carolina or Georgia. 

 These include (1) the location of North 

 Carolina in a transitional zone between 

 the temperate seaweeds of New England and 

 the tropical seaweeds of the Caribbean, 

 (2) the greater abundance of hard 



substrates off the North Carolina coast, 

 and (3) the greater number of seaweed 

 specialists that have investigated the 

 marine flora of North Carolina. Because 

 of the extensive floristic investigations 

 conducted in North Carolina by Searles, 

 Schneider, and Kapraun (Schneider 1976; 

 Searles and Schneider 1978, 1980; 

 Schneider and Searles 1979; Kapraun 1980a, 

 b, 1984; Kapraun and Zechman 1982; Searles 

 1984), the seaweeds of this area are much 

 better known than those in any other part 

 of the South Atlantic Bight. The paucity 

 of data from other regions forces us to 

 focus most of our discussion on the 

 seaweeds of the Carol inas. For keys and 

 illustrations of seaweeds of the South 

 Atlantic Bight, see Taylor (1960) and 

 Kapraun (1980a, 1984). 



The seaweeds growing highest in the 

 intertidal zone are usually blue-green 

 algae that appear as a darkly colored band 

 on the rocks (Figure 5). The most common 

 seaweeds immediately below the blue-green 

 zone are usually the green algae, Ulva , 

 Enteromorpha , and CI adophora , and, at 

 times, the red alga Porphyra . Ulva and 

 Enteromorpha (Figure 6) are bright green 

 seaweeds that often grow intermixed. They 

 are distinguished primarily on the basis 

 of frond morphology. Ulva has a flat 

 membranous frond composed of two cell 

 layers; Enteromorpha fronds are similar 

 except that they are tubular, at least in 

 part. Since some species of Enteromorpha 



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Figure 5. Vertical distribution (L=!evel with respect to Mean Tide Level) of the 20 most abundant sessile species 

 observed at north jetty stations at Murrells Inlet, SC. Band width indicates abundance (Van Dolah et al. 1984). 



