Life Sciences Commons^™

Submerged Aquatic Vegetation In Delaware's Inland Bays, Robert J. Orth, Kenneth A. Moore

VIMS Books and Book Chapters

Submerged aquatic vegetation (SAV) is an important living resource in many coastal areas throughout the world. These plant communities have been cited as some of the most biologically important in the world. ...

Submerged Aquatic Vegetation In The Chesapeake Bay: A Barometer Of Bay Health, Robert J. Orth, Kenneth A. Moore

VIMS Books and Book Chapters

In 1978, a program was initiated in the Chesapeake Bay region to investigate the decline of submerged aquatic vegetation (SA V), potential factors that may have led to its decline, its distribution and abundance, and its .role and value. The program began with little available background data, but some very basic questions about SAV in the Bay were answered in the approximately three years of research that were funded. For example, it was determined that the decline of SAV was Baywide. All SA V species were affected and the decline was unprecedented in the recent history of the Bay. A …

Some Histologic Gill Lesions Of Several Estuarine Finfishes Related To Exposure To Contaminated Sediments: A Preliminary Report, W. J. Hargis Jr., D. E. Zwerner

VIMS Books and Book Chapters

Collections were made during 1983, '84 and '85 in the Elizabeth River, whose sediments are heavily contaminated with PAHs, heavy metals and other anthropogenic materials. Comparison samples were from the "cleaner" Nansemond River, another subestuary feeding into Hampton Roads (the lower James River) nearby. Most samples from all stations included three transient quasi-catadromous nektonic sciaenids, Atlantic croaker (Micropogonias undulatus), spot (Leiostomus xanthurus) and weakfish (Cynoscion regalis), and two endemic estuarine benthic fishes, hogchoker (Trinectes maculatus) and oyster toadfish (Opsanus tau).

Comparison Of Sediment Landscapes In Chesapeake Bay As Seen By Surface And Profile Imaging, Robert J. Diaz, Linda C. Schaffner

VIMS Books and Book Chapters

The sediment-water interface is the boundary layer between the water column and sediments. It is involved in virtually all processes and cycles within aquatic and estuarine ecosystems. Interactions and reactions at the sediment-water interface are of particular importance in regulating processes involving nutrient regeneration-remineralization (Boynton and Kemp 1985), fate of toxicants (Olsen, Cutshall and Larsen 1982), development of hypoxia-anoxia (Garber 1987), sediment mixing (Schaffner et al. 1987a, b), and sediment transport (Wright et al. 1987). Much effort has and is being expended to provide details of these processes which will eventually be used in management plans for water quality, sediment …

Bioavailability Of Organic Pollutants To Aquatic Organisms, Robert C. Hale, Robert J. Huggett

VIMS Books and Book Chapters

Settlement of the Chesapeake Bay region began in earnest in the early 17th century. The native American population and early colonists were impressed by the abundance of fish and shellfish and located their population centers to take advantage of these and other natu!al resources. Introduction of wastes into the bay was coincident with this settlement. As the human population increased, so did the pressure on the ecological system. In the 20th century significant quantities of synthetic chemicals began to be introduced, many of which were toxic and nonbiodegradable [Faust and Hunter 1971]. Today the areas surrounding the bay are experiencing …

The American Oyster Crassostrea Virginica In Cheapeake Bay, Dexter Haven

VIMS Books and Book Chapters

The American Oyster (Crassostrea virginica) is widely distributed in Chesapeake Bay where it grows in the intertidal zone to depths of about 6.5 m. The salinity range over which it occurs, is from about 5 to 34 ° /oo. It is most abundant in protected embayments where bottoms are a firm sand-clay mixed with shelly material. This bivalve is a filter feeder, and ingests planktonic material which it strains from the water with its gills. Spawning occurs in Chesapeake Bay from June through September, and the eggs and resulting larvae are widely distributed during their 10-20 day planktonic life.

Growth …

Submerged And Emergent Aquatic Vegetation Of The Chesapeake Bay, Carl Hershner, Richard L. Wetzel

VIMS Books and Book Chapters

Chesapeake Bay supports a diverse assemblage of submerged and emergent aquatic vegetation. The distribution of species of each kind of vegetation is governed largely by salinity. The functions of both submerged and emergent vegetation in the Bay ecosystem includes contributing to total net primary production, service a habitat and performance in both water quality and sedimentation processes. Research on submerged aquatic vegetation is focused on its role in the estuarine system and determinants of its distribution and abundance. Research on emergent vegetation still concerns basic questions of structure and function, but has also branched into methodologies for utilization by man …

Benthic Resources Of The Chesapeake Bay Estuarine System, Robert J. Diaz

VIMS Books and Book Chapters

The term benthic is derived from the Greek root " benth" which means the depths of the sea. Benthic has then come to mean that which is associated with the bottom of any body of water from lakes to oceans, and encompasses a broad range of organisms from algae to fish. In the Chesapeake Bay there is a wide variety and combination of benthic environments ranging from intertidal flats of sand or mud, shallow seagrass meadows, subtidal bottoms, and deeper channels. These environment take on a unique biological and chemical character, depending upon where they occur along the gradient of …

Contaminant Effects On Chesapeake Bay Finfishes, Ronald J. Klauda, Michael E. Bender

VIMS Books and Book Chapters

Habitat deterioration is consistent with perceived population declines for several resident and anadromous finfish species in Chesapeake Bay that are subjected to different levels of fishing pressure (e.g., striped bass versus blueback herring). Diminution of habitat quality has natural and anthropogenic roots that are difficult to separate. Recent contaminant effects studies focused on Chesapeake Bay fishes can be grouped as follows: (a) mathematical and statistical modeling studies aimed at elucidating contaminant and stock trend relationships using extant data and theoretical insights, (b) biological and chemical field surveys in selected areas to demonstrate spatio-temporal associations between levels of toxic organic and …

Contaminants In Chesapeake Bay: The Regional Perspective, George R. Helz, Robert J. Huggett

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Industrial and municipal point sources of contaminants are scattered along the shores of Chesapeake Bay and its tributaries, but reach especially high density at Norfolk, Va., and Baltimore, Md. Sedimentation and various chemical processes in many cases conspire to restrict the water-borne transport of contaminant away from point source . Kepone, residual chlorine, volatile halogenated hydrocarbons, and anthropogenic trace metals are well-studied example of point-source contaminants. For the most part, their concentration in water and sediment drop to nearly immeasurable values within a distance of a few kilometers, or sometimes a few tens of kilometers, from their source .

On …

Distribution And Abundance Of Submerged Aquatic Vegetation In 1984 And 1985, James D. Simons, Robert J. Orth

VIMS Books and Book Chapters

Communities of submerged aquatic vegetation (SA V) are an integral part of the Chesapeake Bay ecosystem. They provide an important habitat for many species, either as a food source or as protection from predators, i.e., as a nursery. By reducing currents and baffling waves, they allow for deposition of suspended material. In addition, they bind sediments with their roots and rhizomes to prevent erosion of the underlying material. They are important in nutrient cycling through both the absorption and release of nitrogen and phosphorus.

Effects Of Contaminants On Estuarine Zooplankton, Brian P. Bradley, Morrris H. Roberts Jr.

VIMS Books and Book Chapters

The objectives of the chapter are (1) to evaluate laboratory studies concerning effects of heavy metals, pesticides and oxidants on copepods, mysids, bivalve and decapod larvae (2) access field studies (mainly with copepods) on these and other contaminants which when coupled with laboratory data provide information on known and potential hazards of contaminants to zooplankton and (3) briefly review some bioassay methods used in these studies.

Mercury is the most toxic heavy metal by weight, followed by copper, silver and cadmium. Pesticides have been tested much less extensively than heavy metals. In general, bivalve larvae seem less sensitive than the …

Mollusk Culture For The Chesapeake Bay, Michael Castagna

VIMS Books and Book Chapters

The water quality of the Chesapeake Bay has suffered a decline over the last 5 decades due to anthropomorphic activities. Insidious additions of industrial and farm pollutant to the Bay have created a situation where in many areas there are periodic sub lethal levels of chemicals. Although the juveniles and adults seem to survive these levels, they are obviously interfering with some early life stage of the living organisms that make up the bay fauna. Species whose early life history takes place out of the Bay (i.e. Cal!inectes sapidus) are less affected by this problem than those species whose eggs, …

Recent Studies In The United States On Parasites And Pathogens Of Marine Mollusks, With Emphasis On Diseases Of The American Oyster, Crassostrea Virginica Gmelin, William J. Hargis Jr.

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Morphological, systematic, faunal, and life cycle studies predominated research on marine parasites and pathogens in the United States before World War II. Much was primarily basic or academic in nature. Since then it has grown and diversified under pressure or efforts to: I) Increase yields or invertebrate-based fisheries, In nature and under controlled conditions; and 2) understand , protect, and improve the resources, estuarine and marine environments, and human health and welfare. Over the last 30 yr pathobiologlcal investigations of economically and ecologically important marine Invertebrates have broadened into submlcroscopcal anatomy (TEM and SEM technlques), physiology, Immunology, genetics, host-parasite ecology, …

Meaningful Chemical Measurements In The Marine Environment - Transition Metals, James H. Carpenter, Robert J. Huggett

VIMS Books and Book Chapters

The following comments present a critical, but not negative, point of view that seeks identification of improved approaches to "marine pollution effects" studies. The current literature has many examples of the disquiet that the authors experience in reviewing or participating in recent studies. As pointed out by Dayton (1982), in reviewing the proceedings of a symposium: The Shore Environment, "Environmental protection programs are increasingly criticized by ecologists, regulatory and management agencies, and private business as being of questionable quality and value. Because regulatory agencies and many ecologists are uncomfortable with the highly probabilistic nature of ecology, there is a tendency, …

How Do Sediments Enter The Bay, Move Through The System, Remove And Store Chemicals, Or Release Them?, Maynard N. Nichols

VIMS Books and Book Chapters

Escape of more than two million tons of sediment., 4,000 tons of man-made chemicals (e.g. Cd, Cu, Pb and Zn) and more than 300 types of synthetic organic compounds annually into the Bay, shoals shipping channels, reduces water quality and threatens biota. Where then do these enormous loads go? Are they mainly flushed into the sea or stored on the Bay floor? And what happens to chemicals attached to the sediments as they pass through different chemical regimes of the Bay? These are important questions facing scientists who aim to understand the cycling of sedimentary materials and to predict the …

How Should Research And Monitoring Be Integrated?, David A. Flemer, Thomas A. Malone, Herbert M. Austin, Walter R. Boynton, Robert B. Biggs, L. Eugene Cronin

VIMS Books and Book Chapters

Scientific knowledge of Chesapeake Bay and tidal tributaries has accumulated over many years beginning mostly with descriptive surveys prior to the 1960's and 1970's and evolving towards a coupling of monitoring and research in recent years. This essay discusses the need to more fully couple monitoring and research efforts in the Bay system because such a union of efforts is argued to be the most effective way to assess gross trends in the "health" of the system (monitoring) and to understand the basic forces causing these trends (research). We argue that together they provide part of the framework necessary for …

How Can We Best Test The Effects Of Pollutants And Changes On The Animals And Plants Of Chesapeake Bay?, L. Eugene Cronin, Morris H. Roberts Jr.

VIMS Books and Book Chapters

The animals and plants of the Bay, and the processes in which they are involved, are the basis for almost every use and desirable quality of the Bay. They provide both commercial and recreational fisheries, assimilate some quantities of wastes, contribute to esthetic quality, provide a favorable environment for many birds and mammals and feed all of the species which are used by man. However, the biota are directly or indirectly affected by many human activities - by maritime transport, recreational activities, agricultural production, waste discharges, domestic development, engineering activity, and other land-based activities. Therefore, the ultimate and most important …

What Are The Best Guidelines For Dredging And Placement Of Dredged Materials?, Maynard N. Nichols

VIMS Books and Book Chapters

During the~ next 25 years, more than 280 millicm cubic yards of sediment will be dredged from the Chesapeake Bay and its tributaries (Table 1). Altogether more than 800 million dollars will be spent to deepen ports and maintain shipping channels. About one-third of the maintenance dredgin~; will be done in ports and harbors where the sediment is contaminated by industrial wastes and sewage discharge. Because of long-continued disposal of dredged material, the region is losing its physical capacity to assimilate more material. Where then can these enormous loads be placed at acceptable costs? And what are the best guidelines …

Blue Crab Mortalities Associated With Pesticides, Herbicides, Temperature, Salinity, And Dissolved Oxygen, Willard A. Van Engel

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Commercial fisheries landings of the blue crab in the Chesapeake Bay have fluctuated widely since the late 1920s (Figure I). Records of annual landings prior to 1929 are sparse and permit little more than a guess of trends, although a discontinuous series of catch records from 1907 to 1926 from individual watermen, on file at the Virginia Institute of Marine Science (VIMS), may provide sufficient baseline data for interpretations or estimates of trends in the early period.

Distribution And Abundance Of Submerged Aquatic Vegetation In Chesapeake Bay, Robert J. Orth, Kenneth A. Moore

VIMS Books and Book Chapters

The Chesapeake Bay, with its extensive littoral zone and broad salinity regime of Oto 25 ppt, supports many different species of submerged aquatic vegetation (SAV) (Anderson 1972, Stevenson and Confer 1978, Orth et al. 1979). Approximately ten species of submerged vascular plants are abundant in the Bay, with another ten species occurring less frequently. In many areas, more than one species is found in a particular bed of SAV because of the similarity in the physiological tolerances of some species. Between regions of the Bay, salinity appears to be the most important factor in controlling the species composition of an …

Toxic Substances, R. Bieri, O. Bricker, R. Byrne, R. J. Diaz, Et Al

VIMS Books and Book Chapters

This part of the CBP Synthesis Report summarizes and integrates the research findings and reconnnendations of 13 projects of the Chesapeake Bay Toxic Substances Program performed between July 1978 and October 1981. The following sections describe research on potentially toxic substances, or toxicants, in water-sediments and selected biota. The subjects considered include a brief review of metals, their sources, distribution and behavior, and then a review of sources and distribution of organic chemicals. Finally, information concerning the significance of toxicants in the- Bay and their pattern of enrichment is provided. Most information synthesized in this report can be traced to …

Light And Submerged Macrophyte Communities In Chesapeake Bay: A Scientific Summary, Richard L. Wetzel, Robin F. Van Tine, Polly A. Penhale

VIMS Books and Book Chapters

The initial focus of submerged aquatic vegetation (SAV) research in the U.S. Environmental Protection Agency (EPA), Chesapeake Bay Program (CBP) was evaluation of the structural and functional ecology of these communities. In the upper Bay, Myriophyllum spicatum and Potamogeton perfoliatus are the dominant species; the dominant species in the lower Bay are Zostera marina and Ruppia maritima. Studies centered on various aspects of productivity (both primary and secondary), trophic structure, and resource utilization by both ecologically and economically important species. Much of the initial research was descriptively oriented because of a general lack of information on Chesapeake Bay submerged plant …

Distribution And Hydrodynamic Properties Of Fouling Organisms In The Pier 12 Area Of The Norfolk Area Station, Robert J. Diaz

VIMS Books and Book Chapters

Fouling of deep draft naval vessels, in particular aircraft carriers, in the area of the Norfolk Naval Station has been a reoccurring problem since the early 60's. The principal agents of fouling have been the hydroid, Sertularia argentea and the fleshly bryozoan, Alcyonidium verrilli. The particular fouling problem encountered in the Norfolk area is not the typical case of the organisms growing attached to ship hulls but is basically a problem of sea suction and subsequent clogging of screen grates and condenser tube sheets.

Marine Invertebrates, Marvin L. Wass

VIMS Books and Book Chapters

Virginia and Maryland are favored with the largest estuary in the United States-the Chesapeake Bay. The Bay is 289 kilometers (173 miles) long and 47.6 kilometers (28.6 miles) wide near Smith Point. The estuary is relatively shallow, with an average depth of 8.05 meters (26.4 feet) and a maximum depth of 53 meters (174 feet) at Blood Point Light in Maryland. The greatest depth in Virginia is near Smith Point: 44 meters (144 feet) (Wolman, 1968). While this deep hole has probably never been sampled for benthos, many rare species have been collected in an area just south of Smith …

The Marine Algae Of Virginia, Harold J. Humm

VIMS Books and Book Chapters

Starting with initial collections near Yorktown back in 1946, Humm over the years gathered information on algae appearing all seasons of the year from bays, marshes, reefs, wrecks and a variety of substrates from the Eastern Shore, Chesapeake Bay and tidewater areas.

Includes a systematic list of species, keys, descriptions, drawings and images of specimens.

Biomass And Nutrient Flux Measurements On Holothuria Atra Populations On Windward Reef Flats At Enewetak, Marshall Islands, Kenneth L. Webb, William D. Dupaul, Christopher F. D'Elia

VIMS Books and Book Chapters

A population survey of the holothurian, Holothuria atra, on the interisland coral reefs of Enewetak revealed average animal densities of about 3 animals m-2 in the zone of small coral heads, Median fresh weighy was 60 g, The size distribution of these animals was negatively correlated with water velocity along the reef.

Ammonia release rates for three species of holothurians, H. atra, H. difficilus and Actinopyga mauritina were weight specific, The release of annnonia by H. atra on Transect II was equivalent to 9% of the total amnnonia exported from the reef proper. The release of phosphorus followed the general …

Biomass And Nutrient Flux Measurements On Holothuria Atra Populations On Windward Reef Flats At Enewetak, Marshall Islands, C. F. D'Elia, K. L. Webb

VIMS Books and Book Chapters

Although it is reasonably well established that corals symbiotic with endozoic algae (the zooxanthellae) are capable of "multitrophic" (1) existence, we are still a long way away from evaluating the relative importance of the various trophic pathways (2). There is no question that zooplankton provide a source of materials and energy to corals, yet there is doubt whether zooplankton are plentiful enough to supply all the needs for these essentials (3). There appear to be alternate sources of supply. Sufficient energy is likely to be available to the symbiotic association by virtue of the photosynthetic capacity of the zooxanthellae (4); …

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 …