Document Type


Publication Date


Publication Title

Virginia Journal of Science








Monthly and annual phytoplankton productivity rates of four Virginia tidal rivers were determined based on a 12-year monitoring study that included sampling stations from tidal freshwater, oligohaline, and mesohaline regions in these rivers. The mean monthly rates and range at these locations were 5.52 (Dec.) to 175.12 (Aug.) mg C m-3 h-1 for tidal freshwater, 12.21 (Jan.) to 149.90 (May) mg C m-3 h-1 in oligohaline regions, and 16.20 (Jan.) to 151.33 (May) mg C m-3 h-1 for the mesohaline. The estimated mean annual 12 year productivity for the different Virginia river sites in this study ranged from 49 g C m-2 yr-1 to 230 g C m-2 yr-1. The dominant phytoplankton during periods of high productivity included a changing seasonal dominance of flora among the different salinity regions. At least one. station from each river experienced a significant decrease in productivity rates during the 12 years of this analysis. In comparison to an earlier segment of this study, the results indicate the value of long term monitoring to more accurately characterize the productivity dynamics in estuarine locations.

Original Publication Citation

Nesius, K.K., Marshall, H.G., & Egerton, T.A. (2007). Phytoplankton productivity in the tidal regions of four Chesapeake Bay (USA) tributaries. Virginia Journal of Science, 58(4), 191-204.