INDIAN RIVER BAY 



Figure 1. — White Creek, Del., with sampling locations, 

 and water depth at mean low water in meters. 



predominate. On higher ground, pines are 

 abxmdant, primarily loblolly ( Pinus taeda ). 



We analyzed appropriate aerial maps and 

 used a depth profile survey by field station 

 personnel to determine physiographic features. 

 The creek is 4.7 km. long and drains a water- 

 shed of about 15 km.^. The mean low-water 

 surface area is 1.3 km.^, with 80 percent 

 less than 1 m. in depth (figure 2a). Volume at 

 mean low water amounts to about 1,Z80 m.3, 

 with a mean tidal range of 0.5 m. The mean 

 high-water volume is calculated to be about 

 1,940 m.3. Intertidal volume amounts to about 

 34 percent of the mean high-water volume. 



We established eight sampling locations, or 

 stations, along the length of the creek. Station 

 1 was located seaward of a broad, gradually 

 sloping, sandy beach, exposed to wave action 

 from the bay. Station 2, located in a cove 

 extending eastward from inside the creek 

 mouth, was characterized by a narrow, sandy 

 bottom inshore, grading to mud offshore. Sta- 

 tions 3 and 4 were located along narrow sand 

 beaches, sloping gradually to a muddy sand 

 bottom. Stations 5 and 6 were near narrow 

 beaches which sloped to a sandy mud bottom. 

 The upper creek stations, 7 and 8, were 

 located adjacent to extensive intertidal flats, 

 and had sticky mud bottoms. 



Benthic vegetation was abundant seasonally, 

 primarily between stations 2 and 4. The green 

 algae ( Ulva lactuca and Enteromorpha linza) 

 and the red alga (Aghardiella tenera j^ere the 

 principal forms. 



Since detailed description of hydrographic 

 observations will be the subject of another re- 

 port in this series, we summarized only the 

 general features in this report. Seasonal 

 changes of surface water temperature were 

 similar throughout the creek; monthly means 

 and ranges are shown in figure 2b for each of 

 four zones, formed by grouping two adjacent 

 stations. Salinity varied continuously with 

 changes in tide and season, resulting in a wide 

 range of values. The overall mean and range 

 of salinity at each station are shown in 

 figure 2c. 



MATERIALS AND METHODS 



Generally, we collected fish every other day 

 at each station during a 5-day workweek. We 

 used beach seines of different lengths and 

 mesh sizes during the survey. Spring and 

 summer collections were made with a 7.5-m., 

 6-mm. stretched mesh seine, 1 m, deep; fall 

 and winter collections were made witha 30-m., 

 12-mm. stretched mesh seine, 1.3 m. deep. 

 A 15-m., 12-mm. stretched mesh seine, 1.3 nn. 

 deep, was used during the first three sampling 

 days of August on an experimental basis. Be- 

 cause of ice cover during winter and early 

 spring, collections were lacking for periods of 

 up to 2 weeks. 



