Document Title:

Water Quality Survey Report for Potential Sea Grass Restoration in West Bay of the St. Andrew Bay System in Northwest Florida.

Jon M. Hemming Michael Brim Robert Jarvis

PCFO-EC 03-01


Seagrass losses have been reported for the area of St. Andrew Bay known as West Bay, in Bay County, Florida. Utilizing both field density observations and aerial photography extrapolation for 1953, 1964, 1980 and 1992 images, estimated seagrass losses from West Bay have been reported by the U.S. Geological Survey to be almost 2,000 acres or approximately 50%. Noteworthy anthropogenic events altering the condition of West Bay during this time period have included U.S. Army Corps of Engineers’ (USCOE) construction of the Gulf Intracoastal Waterway (GIWW) connection between the oligohaline eastern portion of Choctawhatchee Bay and northwest West Bay in 1938, the 1970 implementation of an aquacultural endeavor involving isolating the southern half of West Bay proper , as well as large sections of the tidal marsh along its shoreline, and the 1970 introduction of a wastewater effluent to southern West Bay from a municipal sewage treatment plant. In an effort to better understand the cause of seagrass losses for the purpose of designing restoration efforts, the U.S. Fish and Wildlife Service conducted a water and sediment quality survey. Suspected sediment contamination (potentially resulting from extensive use of antifouling coatings for nets and equipment during the aquacultural enterprise) was not confirmed with sediment sampling and analysis for metals and organotin compounds. Water column surveys revealed important differences in turbidity (NTU), water clarity (Secchi depth), and salinity (ppt). However, small differences in dissolved oxygen (mg/L), pH (SU), chlorophyll a (ug/L), and temperature (°C) were not thought as important to seagrass loss or restoration efforts. Differences in water quality appeared to be heavily dependent on depth, wind direction, recent precipitation, tidal flow, and proximity to points of allochthonous inputs such as the GIWW, wetland drainage canals created by the Florida Department of Transportation and for silvicultural purposes, urbanization enhanced stormwater runoff, and a wastewater effluent outfall.

U.S. Fish and Wildlife Service



U.S. Fish and Wildlife Service - Panama City Ecological Services and Fisheries Resource Office

Last updated: June 12, 2015