Document Type

Report

Department/Program

Virginia Institute of Marine Science

Publication Date

1-1-2005

Series

Special Reports in Applied Marine Science and Ocean Engineering (SRAMSOE) No. 389

Abstract

In 2003-2004 wild celery (Vallisneria americana) whole shoots and 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. 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 techniques for assessing visual surface water algal conditions and water color characteristics; 4) evaluate the relationships between SAV transplant performance and water quality. SAV growth and survival were evident at all sites when the plants were protected from herbivory. Seeds obtained from wild stock and planted within the exclosures germinated and produced adult plants at each of the sites. The transplanted beds demonstrated limited impacts from hurricane Isabel with losses only evident at one transplant site. Water quality conditions in 2003 and 2004 were characterized by relatively low chlorophyll concentrations in comparison to 2002. River flow appeared to be inversely related to chlorophyll levels with a precipitous drop in chlorophyll evident for 2003 and 2004 (higher flow years) in comparison to 2002 (low flow year). Chlorophyll concentrations in 2003 and 2004 were well below the SAV habitat criteria (15mg/l) that have been associated with SAV growth to 1m. Proposed seasonal numeric chlorophyll limits under consideration by the Va. DEQ for the tidal freshwater James River (10 to 20 mg/l) would have been met in most areas in 2003 and 2004, but not in 2002. Turbidity levels were comparable among both high flow and low flow years. Water column nutrient concentrations did not vary greatly as river flow increased in 2003 and 2004 from lower flows in 2002. High ammonium concentrations found throughout this region in 2002 have not been evident since. Algal condition assessments conducted in 2004 showed little visual algal impairment. Several visual water color assessment techniques using the Flore-Ule color systems and Munsell color charts were also investigated. None were very suitable for quantifying algal and phytoplankton concentrations in this environment. This was partly due to the relative low phytoplankton concentrations present during most of this study period, the confounding effects of the varying ambient conditions, and partly due to the subjective nature of the assessment techniques themselves.

DOI

https://doi.org/10.21220/V51X7N

Keywords

Submerged Aquatic Vegetation, Ecology, Virginia

Funding

HOPEWELL REGIONAL WASTEWATER TREATMENT FACILITY 231 Hummel Ross Road Hopewell, Virginia 23860

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