Survey of SAV of Currituck Sound and Western AP Estuarine System

Surveys of SAV in the Pamlico River system were conducted in 1985, 1987, and 1988 to determine the species present and to estimate their abundance . In 1985 only widgeongrass was found in the river while in 1987 a small amount of wildcelery was found. By 1988 significant stands of wildcelery covered some areas in the middle reach. Wildcelery was stressed both years as indicated by small plants with narrow leaves and frequent fragmentation of leaves . Salinity and heavy epiphytic growth were among the stress factors observed. Traces of Sago pondweed and redhead grass appeared in 1988. Wildcelery transplanted into the Pamlico River system in 1987 and 1988 died at all but one site in 1988 where the species grew naturally.

Wildcelery was common in a portion of the narrow southern littoral in the upper reach of the Neuse River estuary in 1987 and 1988 while there were traces of widgeongrass on both sides of the estuary . Plant biomass in the Currituck Sound decreased from 1973 to 1978 ·and from 1978 to 1988 due to the decrease of Eurasian watermilfoil. In 1987 and 1988 Eurasian watermilfoil and widgeongrass were common in Kitty Hawk Bay while in 1988 diverse SAV communities were found in the Perquimans and Little Rivers. The Pasquotank River was essentially barren.

Except for man-made marsh creeks on South Creek, which also had Eurasian watermilfoil, the smaller tributaries of the Pamlico Sound typically are populated from December through May by horned pondweed which gives way to widgeongrass which usually forms monospecific stands through the s ummer. For reasons unknown, widgeongrass sometimes disappears in the tributaries and in the Pamlico River in August and September.

The Pamlico River and Currituck Sound are two areas of special concern relative to SAV populations. Compared with the Currituck Sound and all but one site in the Neuse River, wildcelery plants in the Pamlico River are in poor condition even though biomass and cover increased significantly in some areas from 1987 to 1988. In addition to epiphytic growth, often heavy, water transparency appears to have decreased drastically in the river since the mid- seventies, but it was about the same as for the Neuse River in the spring of 1988 and greater than for Currituck Sound. It seems unlikely that SAV in the Pamlico River would recover to conditions in the mid-seventies. Although widgeongrass biomass and cover are increasing in the Currituck Sound, biomass and cover are still low. Significant increases in water transparency in the Currituck Sound could lead to regrowth of Eurasian watermilfoil in nuisance proportions.