ULF RESORT 
BEACH 
FLORIDA BEACH 
2 
GULF OF MEXICO 
PLATFORM 
a 
Figure 1.—Survey area and numbered subareas of the St. Andrew Bay system, Fla., and adjacent coastal waters. 
County, Fla., along the northeastern Gulf of Mexico 
(long. 85°23’ to 85°53'W, lat. 30°00’ to 30°20'N). The sys- 
tem is a shallow plain estuary of about 90 square miles 
(233 km?). It consists of North Bay, West Bay, East Bay, 
and St. Andrew Bay. Two passes (East Pass, a natural 
channel, and West Pass, an excavated channel) connect 
St. Andrew Bay to the Gulf of Mexico. 
For statistical and logistical reasons the study area was 
divided into four major areas and each major area into 
several subareas. The major areas were: 1) North and 
West Bays, 2) East Bay, 3) St. Andrew Bay, and 4) 
coastal waters. All bayous and brackish water creeks 
were included in the areas that could be navigated by 
outboard motorboat or surveyed from an outboard 
motorboat with the aid of binoculars. 
MARINE ESTUARINE FEATURES 
The St. Andrew Bay system was described by Waller 
(1961) as a positive estuary, in that freshwater inflow ex- 
ceeds evaporation. Econfina Creek, which is dammed at 
Deer Point in West Bay, is the principal source of fresh- 
water in the system. Several small creeks contribute to 
the total inflow. The inland bays are generally less saline 
than the coastal bay. St. Andrew Bay salinity ap- 
proaches that of the Gulf of Mexico waters (hereafter 
referred as gulf waters) (Hopkins 1964). That salinity 
and turbidity are related was also revealed by Hopkins 
(1964); the lower saline waters of the inland bays have 
the highest turbidity. Waller (1961) found lower 
salinities and transparencies on the westward side of the 
bay system. Ichiye (in Waller 1961) suggested the con- 
dition may result from the Coriolis effect. Repeated ob- 
servations have shown that gulf waters are usually less 
transparent west of West Pass than to the east. Floating 
vegetation of estuarine and freshwater origin is frequent- 
ly seen off West Pass and seldom off East Pass, sug- 
gesting that most of the freshwater flows out of the sys- 
tem through West Pass. 
The bay system has mean depths of 1.8 m in North 
Bay, 2.1m in West Bay, 2.1 m in Kast Bay, and 5.2 m in 
St. Andrew Bay (Waller 1961). Maximan depths to about 
15 m are found in ship channels in West Pass and St. An- 
drew Bay and in the intracoastal waterway through East, 
St. Andrew, and West Bays (National Ocean Survey, 
Nautical Chart 868-5C). 
East Pass is not maintained, hence it is comparatively 
shallow and has a constantly shifting entrance channel. 
