Submerged Aquatic Vegetation of Coastal Alabama - Summer Polygon Data (MBNEP Survey 2015)

This data set consists of digital vector data describing the location and species composition of submerged aquatic vegetation in coastal Alabama during summer 2015, including Mississippi Sound, Mobile Bay, Mobile-Tensaw Delta, Little Lagoon, Bay La Launch, Perdido Bay, and their communicating tributaries. The data set includes 1,068 orthophotograph frames and a MrSID mosaic produced from digital aerial imagery acquired on July 17, 18, and 19 and August 23, 25, and 26. SAV was concentrated in upper Mobile Bay and the Mobile-Tensaw Delta, Mississippi Sound, and the Perdido Key area of southeast Baldwin County. Most of the 2015 SAV acreage occurred in the lower Mobile-Tensaw Delta, particularly in the Bridgehead Quadrangle, which contained 65% (5,905.0 ac) of the total 9,124.3 acres mapped. Other areas of substantial acreage included the Mobile Quadrangle (1,021.2 ac) in the Delta and the Grand Bay Quadrangle (414.6 ac) in Mississippi Sound. Seventy-eight percent of the total SAV acreage (7,116.7 acres) was mapped as continuous (>50%) coverage. Overall, there were 3,875.6 more acres mapped in 2015 than in the 2009 MBNEP survey, mostly due to a 2,454.7-ac increase in the Bridgehead Quadrangle and a 511.4-ac increase in the Mobile Quadrangle. Locations that had no SAV in 2009 but had substantial acreage in 2015 included areas in the Dog River, Chickasaw Creek, and West Fowl River watersheds. Of the 28 habitat categories, most were comprised of mixtures of species occurring in oligohaline systems of the study area.