Distribution of Submerged Aquatic Vegetation in the Lower St. Johns River, 2001 Atlas

This atlas shows results of submerged aquatic vegetation (SAV) monitoring for 2001. Two methods were used to monitor SAV: (1) aerial photography followed by interpretation and (2) groundtruthing transects. In contrast to earlier photo interpretation, the 2001 images were digitized and unsupervised classification was used to detect SAV and emergent vegetation. Unsupervised classification did not appear to be a successful method for identifying SAV in the Lower St. Johns River Basin, as it detected only 570 acres and failed to detect SAV at the majority of groundtruthing transects where it existed. Interpolation of transect data suggest that grass beds covered upwards of 3,000 acres of SAV in the main stem of the river in 2001. Given the large discrepancy between these values, precise estimates of total acreage are tenuous at present.

Publisher - St. Johns River Water Management District (SJRWMD)

Subjects - Submerged Aquatic Vegetation (SAV); Lower St. Johns River

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Citation: Dobberfuhl DR, Trahan N. 2003. Distribution of Submerged Aquatic Vegetation in the Lower St. Johns River, 2001 Atlas. Palatka (FL): St. Johns River Water Management District (SJRWMD); SJ2003-PP1. 52 pp http://www.sjrwmd.com/technicalreports/pdfs/PP/SJ2003-PP1.pdf