Virginia Institute of Marine Science
Special Reports in Applied Marine Science and Ocean Engineering (SRAMSOE) No. 392
In 2005, wild celery (Vallisneria americana) whole shoots, seeds and intact seed pods with seeds were transplanted into four sites in the Hopewell region of the tidal James River. The SAV transplants were sampled by the Virginia Institute of Marine Science (VIMS) for survivorship and growth at bi-weekly to monthly intervals throughout the growing season. Concurrently, water quality sampling was conducted at bi-weekly intervals throughout the year for water column nutrients, chlorophyll a, suspended solids, water transparency and other chemical and physical constituents important for SAV growth. Continuous underway sampling was also conducted along the James River tidal freshwater segments from the mouth of the Chickahominy River to the upstream limits of tidal water at Richmond. Objectives of the study were to: 1) expand the SAV transplanted plots within the study sites previously transplanted; 2) conduct water quality sampling using both fixed station and continuous underway Dataflow sampling; 3) evaluate the relationships between SAV transplant performance using seeds and whole plants and water quality. SAV transplant growth and survival were evident at all sites at depths of approximately 0.4 m below low water, when the plants were protected from herbivory by exclosures. Seeds obtained from wild stock and planted within the exclosures germinated and produced adult plants at each of the sites. The use of seeds of wild celery harvested from reproductive shoots collected in the Potomac River during the fall of 2004 proved successful. Seedlings sprouted within one month of planting at all transplant sites. The whole shoot transplants suffered some initial losses but survivorship was approximately 40% to 70%. Both seedlings produced from seed, and seed pod plantings, as well as transplanted whole shoots that were not protected by protective fencing were heavily grazed and did not survive throughout the summer. Water quality monitoring in the tidal James River in 2005 indicated continued adequate water quality for SAV growth. Turbidity levels, while highest in the upper JMSTF1 segment and lower JMSTF2 segment, were suitable for SAV growth to depths of 0.5 m in most areas. In part this is likely due to the availability of light at low tidal periods when shoot leaves can reach the water’s surface. Phytoplankton levels, measured as chlorophyll, were largely within surface water chlorophyll standards and water quality criteria for SAV growth in most areas. When integrated across the entire segments using continuous underway spatial sampling, average concentrations were found to generally be within criteria limits, except during the mid-summer. Phytoplankton did appear to contribute to reduced water clarity, although this proportion was much smaller than that caused by suspended sediments. Nutrient levels generally were comparable with earlier years’ monitoring results and long term increasing or decreasing trends since 1999 were not evident. Summertime chlorophyll levels in 2005 were higher than 2004, but much lower than those observed in 2001 and 2002. These differences may be related to water residence time in this tidal freshwater region of the James River, with highest concentrations generally observed during lower flow years. Higher salinities, and therefore lower flow and reduced flushing, in 2005 may have caused the slightly higher chlorophyll levels observed during the summer of 2005.
Submerged Aquatic Vegetation, Ecology, Virginia
Moore, K., Neikirk, B., & Anderson, B. (2006) Water Quality Conditions and Restoration of Submerged Aquatic Vegetation (SAV) in the Tidal Freshwater James River 2005. Special Reports in Applied Marine Science and Ocean Engineering (SRAMSOE) No. 392. Virginia Institute of Marine Science, College of William and Mary. https://doi.org/10.21220/V5NR0V