DAHLBERG: ECOLOGICAL STUDY OF GEORGIA COASTAL FISHES 



Figure 3. — View of Sapelo Beach at low tide with Atlantic Ocean and shrimp boat in 

 background and an intertidal slough in center. Fishes become concentrated and 

 trapped in these sloughs at low tide. 



it necessary to arbitrarily define the beach hab- 

 itat to include waters occurring within the 

 wading depth of collectors (about 4 ft). The 

 station is subject to tidal changes — tide ranges 

 from 4.5 to 10.5 ft and has a mean of 6.8 at 

 Sapelo Island (Ragotzkie and Bryson, 1955). 



Habitat 2: Lower reach of the estuary. — 

 This habitat includes the sounds and polyhaline 

 river stations. My records for this habitat are 

 based primarily on trawl collections at stations 

 1-9 and 12-14 (Figure 1). A temperature-sa- 

 linity diagram (Figure 4) does not indicate any 

 relation between these factors. 



Habitat 3: High marsh. — This habitat is the 

 upper section of the littoral zone in the salt 

 marsh. I sampled pools behind high marshes 

 and a tidal ditch in a high marsh but not the 

 high marsh proper. Fishes of this habitat were 

 thoroughly surveyed by Miller and Jorgenson 

 (1969) and are listed in column three of Table 2. 

 Their marsh stations were located near Jekyll 

 Island and near Doboy Sound. The substrate 



of this habitat is sand and mud that is firm 

 enough to walk on, as opposed to the low marsh 

 which has a soft mud substrate. 



Habitat 4: Middle and upper reaches of the 

 estuary (Figures 2 and 5). — The middle reach 



32 



28- 



o 



Lj24 

 <20 



LJ 



I 16 



llJ 



12- 



FiGURE 4.— Temperature-salinity diagram for St. Cath- 

 erines Sound at trawl station 7. Numbers represent con- 

 secutive months from January 1968 to January 1969 ex- 

 cept 12 is December 1969. 



8 



26 28 30 32 



SALINITY 7< 



bo 



327 



