Research Product

The distribution and abundance of submerged aquatic vegetation (SAV) in the lower Chesapeake Bay was delineated with aerial photography and surface information. All SAV were mapped from aerial imagery onto topographic quads (1:24000) with a zoom transfer scope. The SAV beds were classified into 4 density categories based on comparison with a crown density scale. A comparison with earlier surveys indicates that the distribution of the SAV species found in the saline portions of the bay have shifted from upriver and upbay sites to the mouths of rivers and lower bay sites. SAV beds in six selected areas of the lower bay were examined for historical changes in the distribution and abundance of SAV. Aerial photographs examined show sparse coverage of grass in most areas in 1937 with dense coverage in the 1950's and 1960's continuing through 1971. Significant declines were noted in the period of 1971 through 1978. The distribution of SAV species in Virginia's tidal waters was classified into three groupings : (1) (Zostera and Ruppia) dominates the saline portions (2) (Potamogeton, Zannichelia) Ologohaline regions (3) (Ceratophylum, Majas) fresh water.