A Study of Dredging Effects in Hampton Roads, Virginia
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W&M ScholarWorks Reports 3-1-1981 A Study of Dredging Effects in Hampton Roads, Virginia Walter I. Priest III Virginia Institute of Marine Science Follow this and additional works at: https://scholarworks.wm.edu/reports Part of the Marine Biology Commons Recommended Citation Priest, W. I. (1981) A Study of Dredging Effects in Hampton Roads, Virginia. Special Reports in Applied Marine Science and Ocean Engineering (SRAMSOE) No. 247. Virginia Institute of Marine Science, College of William and Mary. https://doi.org/10.21220/V51J06 This Report is brought to you for free and open access by W&M ScholarWorks. It has been accepted for inclusion in Reports by an authorized administrator of W&M ScholarWorks. For more information, please contact scholarworks@wm.edu. ------·--=--=-=============;====================;, . - 1s• 7_5° 7~ 7~ ,.---~------- __ ,; I / _.! ,- _,.- ti _: I ~' __ ., _.· I ,· ! , / ' ••••• •' .L_-:.:> ---~·.: , .. -{ ; r·- .------ ~ .:: ; / . ''. _: .::~:-' . I I I·3s, I i ~ _. ;_, i -~ : ... r :; : !~[-{ I .l!i: i :ffe;:/ ,..-.. , i~tfY/ ;_L. ______ -:;.--:;:---.-::::-:-=-:;:;:~~·~~.,=-=--=~=-:::=======7=·5=·==========7=4=·==========7=3·========:.1 A STUDY OF DREDGING EFFECTS IN HA.i.'\fPTON ROADS, VIRGINIA Final Contract Report prepared for: U.S. Army Corps of Engineers Norfolk District 803 Front Street Norfolk, Virginia 23510 under Contract No. DACW65-78-C-0029 by Virginia Institute of Marine Science School of Marine Science College of William and Mary Gloucester Point, Virginia 23062 Walter I. Priest, III, Editor March, 1981 Special Report in Applied Marine Science and Ocean Engineering No. 247 Table of Contents Page Introduction Marine Resource Descriptions Nekton Utilization of Aquatic Resources in the Elizabeth and the Lower James Rivers by M. Y. Hedgepeth, J. V. Merriner and F. Wo j ick ........ a • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 4 Oyster and Hard Clam Distribution and Abundance in Hampton Roads and the Lower James River. by D. S. Haven, R. Morales- Alamo and \'17'. I. Priest • • • • • • • • • • • • • • • • • • . • • • • • • • • • • • . • . • • • • • • • 38 Spawning Activity and Nursery Utilization by Fishes in Hampton Roads and its Tributaries by W. I. Priest •.••.......•. 49 Model and Physical Environment A Model for Dredge-Induced Turbidity by A. Y. Kuo and R . J . Lukens . • . • . • . • • • . • . • . • . • . • • . • . • . 5 5 Suspended Sediment Experiment and Model Calibration by C.S. Welch, R.J. Lukens and A.Y. Kuo •..•.•....•.•.•......•. 130 Near Bottom Currents in the Lower James and Elizabeth Rivers by C. S. Welch ••.....•••••••.•••.•..••••••••••..••••••• 201 Elizabeth River Surface Circulation Atlas by J.C. Munday, H. H. Gordon and C. J. Alston •••....••.••...••.•••..•. 236 Dredging Effects The Effects of Dredging Impacts on Water Quality and Estuarine Organisms by W. I. Priest •••.••••••••••••.•.••..•........••••. 240 Sununary and Conclusions • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • · • • • • • • •. 262 1 Introduction The environmental consequences of dredging and spoil disposal are among the most extensively studied of all of the impacts associated with construction activities performed in aquatic ecosystems. Because the dredged material must be disposed of, the operations are often con sidered synonymous. This can present problems when assessing the environ mental impacts of a project because the majority of adverse impacts are associated with the disposal operations in open-water rather than the dredging per se. This synonymy is unfortunate when the dredged material is being placed in a confined upland site whereby a major portion of the adverse impacts to the environment are being eliminated or greatly reduced. The intent of this report is to identify and quantify, in part, the adverse effects associated with the dredging operation itself and those segments of the ecological community which might be adversely affected by the levels of suspended solids and sedimentation attributable to the dredge. It consists of three sections including: a comprehensive review of the major marine resources, their location in and utilization of the Hampton Roads Harbor and vicinity; the turbidity model and physical environ ment, describing the levels and distribution of suspended sediment and sedimentation and local current patterns; and a review of the effects of increased suspended sediment loads on estuarine organisms and water quality. The first section on marine resources contains chapters of finfish, shellfish and ichthyoplankton. The finfish report summarizes the results of comprehensive trawl surveys performed during 1978 and 1979. · These data were analyzed for the seasonal distribution of both resident and migratory species and nursery areas utilized by juveniles. 2 The shellfish report details the distribution of the oyster, Crassostrea virginica, and the hard clam, Mercenaria mercenaria, in Hampton Roads and the lower James River. The oyster data are based on the different densities of oysters associated with three types of substrate, oyster rock, mud and shell and sand and shell, which represent the areas where oyster populations are densest. Also included are data on oyster spatfall for the years 1976-1979 at selected stations in the study area. The hard clam data depict their distribution and abundance in the Hampton Roads area. The ichthyoplankton chapter reports the seasonal distribution of fish eggs and larvae in and near the study area based on recent research. The data from the lower Chesapeake Bay can be extrapolated to a limited extent to include Hampton Roads and that from the Southern Branch of the Elizabeth River is directly applicable to other Hampton Roads tributaries. The first two chapters of the second section of this report describe the model and the field calibration experiments developed to predict the distribution of dredge-induced suspended solids and sedimentation and the various facets of the dredging operation which influence their generation and distribution. Also included in this section a:re detailed descriptions of the surface and near bottom currents in the study area which also affect the distribution of the suspended solids. The final section of this report presents a review of the literature concerning the environmental impacts of increased suspended solids levels created by dredging. These impacts include: increased turbidity levels, changes in dissolved oxygen, sedimentation and their effects on various estuarine organisms. This report is intended to provide an effective scheme for the evaluation of the impacts of dredging in the Hampton Roads area. By providing detailed quantified distributional data on the important resources 3 of the area, an accurate means of predicting the distribution of increased suspended solids levels and a means of approximating which organisms are going to be affected by the predicted increase, it is hoped that well informed decisions can be made regarding dredging activities in Hampton Roads. MARINE RESOURCE DESCRIPTIONS Nekton Utilization of Aquatic Resources in the Elizabeth River and the Lower James River by Marion Y. Hedgepeth, John V. Merriner and Frank Wojcik Virginia Institute of Marine Science School of Marine Science College of William and Mary Gloucester Point, Virginia 23062 March, 1981 4 Nekton Utilization of Aquatic Resources in the Elizabeth River and the Lower James River by Marion Y. Hedgepeth, John V. Merriner and Frank Wojcik Introduction The Chesapeake Bay and its tributaries provide the state of Virginia with some if its' greatest natural resources. Our blue crab, oyster and finfish industries are three of the largest commercial fisheries on the east coast of the United States. Al though a mgj.or portion of one of Virginia's largest tributary systems (the James River) has been closed to most shellfishing and finfishing since 1976 due to I<e,;,one contamination, it still provides seasonal anQ permanent residence for large populations of shellfish and finfish. The lower James River area (Hampton Roads) and the Elizabeth River provide an estuarine habitat for many commercially and recreationally important species. For example, the Elizabeth River and the lower James River are important nursery grounds for spot, Atlantic croaker, Atlantic menhaden, weakfish, striped bass, black seabass, and summer flounder. Furthermore, they are important as feeding grounds for adult bluefish, weakfish, spot, and Atlantic croaker. Anadromous species such as ·striped bass, American shad, blueback herring and alewife travel through these areas to reach their freshwater spawning grounds. 5 The purpose of this study was to investigate nekton utilization of the Elizabeth River and the lower James River and to establish specific uses. Subsequently, this information would be used by the Army Corps of Engineers for scheduling dredging projects at times and locations for least i~pact on the nekton community. Studies by Virginia Institute of Marine Science (VIMS, Musick et al., 1972 and Rooney-Char, and Ayres, 1978), and the U.S. Army Corps of Engineers (1977) addressed several 9roblems associated with dredging operations and nipeline landfall sites in our present study areas. They concluded that the two r.ajor impacts would be the removal of benthic organisms which serve as fish food and the resusoension of sediments. The latter would affect fish by increasing turbidity, altering respiration rates and predator-prey behavior, and by resuspending heavy metals