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Response And Recovery To Sediment Influx In The Rappahannock Estuary: A Summary, Maynard M. Nichols, Galen Thompson, Bruce Nelson

VIMS Books and Book Chapters

Flooding from Tropical Stonn Agnes produced unique hydrographic conditions for transport and dispersal of sediment in the Rappahannock and .James estuaries. Analyses indicate two cycles of response and recovery to the shock of extreme freshwater and sediment influx; one cycle in response to Rappahannock inflow; the other to intense mixing within the estuary. Important stages in the sequence consist of: (1) an initial response and seaward surge of river water and sediment; (2) shock with downstream translation of the salt intrusion head with a near-bottom salinity front and high turbidity in surface and in bottom water; (3) rebound with intense …

The Effect Of Tropical Storm Agnes On Heavy Metal And Pesticide Residues In The Eastern Oyster From Southern Chesapeake Bay, M. E. Bender, R. J. Huggett

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The concentrations of cadmium, copper, and zinc in the eastern oyster, Crassostrea virginica, are compared for samples collected before and after Tropical Storm Agnes. The "before" samples consisted of 475 animals from 95 stations collected in January 1971 and the "after" samples of 285 animals from 57 stations collected in January 1973. Shifts in the areal concentrations distributions were observed, apparently due to Agnes. Analyses of hard clams, blue crabs and oysters for chlorinated hydrocarbon pesticides showed influx of these compounds to be minimal as reflected by the residue levels observed. Comparison of residue levels in oysters to pre-Agnes conditions …

Modern And Holocene Formanifera In The Chesapeake Bay Region, Robert L. Ellison, Maynard M. Nichols

VIMS Books and Book Chapters

Estuaries are highly variable coastal ecosystems. Some of the variation is seasonal and some is longitudinal along the environmental gradient from the river to the sea. Foraminifera are tuned to the periodicity, and a progressive change in the composition and structure of foraminiferal faunas parallels the longitudinal ecocline, identified by the gradient in salinity.

In marshes and tributary estuaries where water is fresh, thecamoebinids comprise the microfauna. Three other marsh faunas are composed chiefly of the agglutinate species: Ammoastuta salsa, Miliammina fusca, Arenoparrella mexicana, Alllmobaculites crassus and species of Haplophragmoides and Trochammina. Their distribution is influenced by salinity and exposure. …

Changes In Salinity Structure Of The James, York And Rappahannock Estuaries Resulting From The Effects Of Tropical Storm Agnes, Paul V. Hyer, Evon P. Ruzecki

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The peak effect of the flood waters produced by Tropical Storm Agnes was seen on June 25 in the James, June 26 in the Rappahannock, and June 30 in the York. Recovery toward normal salinity conditions after the high runoffs proceeded discontinuously, with alternating periods of vertical stratification and destratification. During strongly stratified stages, saline water advanced upstream along the bottom. In the York and James Rivers, the most dramatic stratification occurred about July 20- 25. This event resulted in bottom salinity values exceeding normal ambient values and, at the river mouths, reaching values hitherto unobserved. This event was apparently …

The Effects Of Tropical Storm Agnes On Fishes In The James, York, And Rappahannock Rivers Of Virginia, Walter J. Hoagman, Woodrow L. Wilson

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Intensive trawl surveys during and after Tropical Storm Agnes were mounted on the James, York, and Rappahannock Rivers to measure the effects of the floodwaters on the distribution and abundance of fish. The direct effect of Agnes on the fish populations was minor and temporary. The normal zone was extended downriver. A substantial portion of the lower-river (marine) species was also displaced downstream and into Chesapeake Bay, but had returned by the follow-up surveys. No adult mortalities due to Agnes were detected. Although we know vast quantities of fish larvae and other plankton were swept into Chesapeake Bay, the overall …

Status And Distribution Of Alosine Stocks In Chesapeake Bay, William H. Kriete, Joseph G. Loesch

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This paper reports the present status of the alosine stocks in Virginia and attempts to explain trends of the past 10 years. This paper is a portion of a completion report "The Biology and Management of River Herring and Shad in Virginia," in partial fulfillment of Contract No. 04-5-043-11 with the National Marine Fisheries Service.

Anadromous Fishes Of The Potomac Estuary, John V. Merriner

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Anadromous fishes have been and continue to be important members of the ichthyofauna within the tidal waters of the Potomac River and other tributaries of Chesapeake Bay in the ecological, commercial, recreational and aesthetic sense. Attributes of the Potomac River basin and its waters have been described in several earlier presentations and shall be cited herein only as they apply to anadromous fishes.

The Effects Of The Agnes Flood On The Salinity Structure Of The Lower Chesapeake Bay And Contiguous Waters, A. Y. Kuo, E. P. Ruzecki, C. S. Fang

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The transient response of salinity distribution in lower Chesapeake Bay to flood waters from Tropical Storm Agnes is studied in terms of a two-layered, partially mixed estuary. Prior to 30 June 1972, surface salinities were well depressed throughout the Bay while those at the bottom near the Bay mouth were not depressed by 5 July. This resulted in a highly stratified situation normally found in the spring of the year. Stratification decreased when bottom waters were flushed down-bay by the flood (on 5 to 10 July for the region south of New Point Comfort). The "rebound" of salinity structure started …

The Effects Of Tropical Storm Agnes On The Copper And Zinc Budgets Of The Rappahannock River, Robert J. Huggett, Michael E. Bender

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The metals copper and zinc were analyzed in bottom sediments (top 1 cm) from the Rappahannock River before and after Tropical Storm Agnes. By extracting the sediments with various techniques (HN03, HCl) the nature of the metal speciation can be estimated. Data show that the inorganic copper was increased by a factor of 2 to 3 in the normally saline portion of the river as a result of Agnes but returned to before-Agnes levels within one year. Metal analyses of suspended sediments collected during the Agnes flooding allows an estimate of sedimentation indicating at least 7.5 mm of new sediments …

Flood Wave-Tide Wave Interaction On The James River During The Agnes Flood, John P. Jacobson, C. S. Fang

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During the Agnes flood hourly tidal height data were collected at seven locations along the tidal James River and currents were measured at two transects in the lower James. A comparison between actual tides and currents and the predicted tidal features as given by the tide and tidal current tables of NOAA was made. Results of this comparison show that Agnes did significantly affect water levels in the upper portion of the tidal James, especially near Richmond. However in the lower portion of the James no discernible rise was evident due to the passage of the flood crest. A small …

Effects Of Tropical Storm Agnes On Nutrient Flux And Distribution In Lower Chesapeake Bay, C. L. Smith, W. G. Macintyre, C. A. Lake, J. G. Windsor Jr.

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Nutrient concentrations measured in lower Chesapeake Bay in the summer of 1972 immediately following the flooding associated with Tropical Storm Agnes are compared with those in the summer of 1973, a season of more normal rainfall. The large amount of land runoff produced unseasonably high concentrations of dissolved inorganic nitrogen in the Bay near the mouth of the Potomac River. Phosphate concentrations were essentially unaffected by the flooding. Fluxes of total nitrogen and total phosphorus nutrients through the mouth of Chesapeake Bay were calculated for both summers. The calculated net export of nutrients from the Bay in both August 1972, …

Observations On Dissolved Oxygen Conditions In Three Virginia Estuaries After Tropical Storm Agnes (Summer 1972), R.A. Jordan

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Dissolved oxygen (DO) and salinity levels in the James, York, and Rappahannock estuaries were monitored for approximately two months (June 24-August 31, 1972) following Tropical Storm Agnes. DO depressions developed more rapidly and were more severe in the deep waters of the York and Rappahannock than in the James. Depressions that developed immediately after the storm were followed by recoveries and subsequent, more severe depressions. In late July, bottom water DO concentrations below 1 mg/1 were found at stations covering 15 miles of the York and 25 miles of the Rappahannock. Comparison of river data with Chesapeake Bay data suggests …

Effects Of Tropical Storm Agnes On Zooplankton In The Lower Chesapeake Bay, George C. Grant, Burton B. Bryan, Fred Jacobs, John E. Olney

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Sampling techniques in use since August 1971 were employed to study effects of Tropical Storm Agnes on lower Chesapeake Bay zooplankton following the storm's passage on June 21, 1972. Mean catches of copepods, cladocerans, barnacle larvae, decapod larvae, chaetognaths, and fish eggs and larvae were calculated for the entire study area and six subareas from 8" bongo net collections. A single subarea was selected for specific identifications within major taxa of zooplankton.

The Effect Of Tropical Storm Agnes As Reflected In Chlorophyll A And Heterotrophic Potential Of The Lower Chesapeake Bay, Paul L. Zubkoff, J. Ernest Warriner Iii

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A hydrographic station (Station Y) at the mouth of the York River (37°14.6'N, 76°23.4'W) was under biological surveillance for one year prior to the arrival of Tropical Storm Agnes. For one full year following this storm, these measurements were continued. In addition, the chlorophyll a and heterotrophic potential measurements were incorporated into an ongoing zooplankton sampling program of the lower Chesapeake Bay below 37°40'N latitude.

Patterns Of Distribution Of Estuarine Organisms And Their Response To A Catastrophic Decrease In Salinity, Peter F. Larsen

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The occurrence of Tropical Storm Agnes during an ongoing study on the community structure of the macrobenthos associated with the James River oyster reefs provided a unique opportunity to document the responses of this assemblage to such a disturbance. The spatial and temporal patterns of abundance of 18 important taxa are examined in this paper. Eight species exhibited limited up estuary penetration, six were most successful in the upper part of the estuarine segment studied, two were most abundant in the mid-section of the study area, and two were ubiquitous. In the post-Agnes period, .six species exhibited reduced population levels, …

The Effect Of Tropical Storm Agnes On Oysters, Hard Clams, Soft Clams, And Oyster Drills In Virginia, D. S. Haven, W. J. Hargis Jr., J. G. Loesch, J. P. Whitcomb

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Tropical Storm Agnes had a major effect on the molluscan fisheries of Virginia. One effect was the direct mortality of oysters, Crassostrea virginiaa, in the upper parts of many estuaries. Typical losses on leased bottoms were: the James River, 10%; the York River, 2%; the Rappahannock River, 50%; and the Potomac River tributaries (Virginia) 70%. Economic loss was in excess of 7.9 million dollars. There was a nearly complete absence of oyster larvae attachment (setting) in 1972. Other effects of Agnes included a nearly complete loss of soft clams, Mya arenaria, in the Rappahannock River. Hard clams, Meraenaria meraenaria, were …

Public Health Aspects Of Tropical Storm Agnes In Virginia's Portion Of Chesapeake Bay And Its Tributaries, M. P. Lynch, J. Claiborne Jones

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All Virginia waters within Chesapeake Bay were closed for the taking of shellfish for direct consumption on 23 June 1972. This initial closing was in anticipation of high microorganism levels accompanying flood waters moving downstream. Various areas beginning with the lower portion of Chesapeake Bay were reopened beginning )n 20 July 1972. By 5 October 1972 all areas closed as a result )f Tropical Storm Agnes were reopened. No increased incidents of infectious diseases caused by waterborne microorganisms were noted in Virginia which could be attributed to Tropical Storm Agnes.

The Displacement And Loss Of Larval Fishes From The Rappahannock And James Rivers, Virginia, Following A Major Tropical Storm, Walter J. Hoagman, John V. Merriner

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Two days after Tropical Storm Agnes, the Virginia Institute of Marine Science (VIMS) established an anchor station at Mile 15 in the Rappahannock and Mile 10 in the James River. Both stations were in mainstream, manned constantly for 10 days, and took continuous current data from meters placed at 0, 6, 8, and 15 min the Rappahannock and 0, 4, 5, 8, and 14 min the James. Concurrently, 0.85 m diameter plankton nets of No. 1 nylon mesh were hung in the flowing surface water for 10 minutes hourly. A small collection of midwater (4 m) plankton samples was obtained …

Effect Of Tropical Storm Agnes On Setting Of Shipworms At Gloucester Point, Virginia, Marvin L. Wass

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Surveillance of shipworm infestation at Gloucester Point, Va., began in 1958. Borer attack by Bankia gouldi occurred in July to early October each year until the passage of Agnes greatly reduced setting. Populations returned to near normal in 1975. Salinity was shown to vary with watershed rainfall.

The Effect Of Tropical Storm Agnes On The Benthic Fauna Of Eelgrass, Zostera Marina, In The Lower Chesapeake Bay, Robert J. Orth

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Tropical Storm Agnes caused major changes in the macroinvertebrate assemblages of both epifauna and infauna in eelgrass, Zostera marina, beds. Species abundance and density of infauna declined by one-third to one-half of values found prior to Agnes. Typical members of the infaunal community such as the amphipods, Ampelisca spp. and Lysianassa alba, the polychaetes Sabella microphthalma and Exogone dispar, ostracods and gastropods were either absent or rare following Agnes. Epifaunal density was much higher than that recorded before Agnes but the number of species was reduced. This high density was attributed to several species, e.g. Molgula manhattensis, which appeared to …

Methods For Measuring Ecosystem Stress, R. J. Huggett, M. E. Bender

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If one looks back over the past twenty-five years, at the pollution crises which have made the headlines and influenced our decision making policies on both local and national levels, one may note a very interesting aspect. That is, the crises are often associated with the development of new and more sensitive types of analytical instrumentation. Several examples of this readily come to mind: for example, it wasn't until the development of electron capture detection for gas chromatography that DDT really became a crisis. The reason is quite simple: the concentrations which were being accumulated by the organisms were below …

The Shellfish Fisheries Of The Potomac River, Dexter S. Haven

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The Potomac and its tributaries support many species of molluscs which are important sources of food for benthic invertebrates, fish, and waterfowl. However, only two species, the American oyster Crassostrea virginica and the soft clam Mya arenaria are harvested for commercial purposes. A third species, the brackish water clam Rangia cuneata occurs locally in tremendous concentrations, but it is not utilized as a food source. Nevertheless, this species is regarded as a potential source of food for people.

During the past six to eight years, commercial landings of both the oyster and the soft clam have dropped from high to …