Michael E. Bender and Robert J. Huggett
The paper reviews contaminant effects on Chesapeake Bay shellfish from two avenues (1) adverse biological effects on the organisms and (2) fisheries closures due to bacterial and chemical contamination. The use of shellfish to monitor anthropogenic inputs of chemical contaminants is also discussed. Fisheries closures due to bacterial contamination account for the greatest economic loss due to man's activities. Kepone contamination in the James River, Virginia caused fisheries closures but has not appeared to cause biological damage to the resources. Organotin compounds from antifouling paints appear to pose a threat to Chesapeake Bay shellfish.
George R. Helz and Robert J. Huggett
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 the other hand, certain contaminants have now been shown to be truly regionally dispersed. Included are polychlorinated biphenyls, phthalate esters, anthropogenic trace metal (Cu, Zn, Pb), polycyclic aromatic hydrocarbons, herbicides and weapon derived radionuclides. Most of these enter the Bay in significant amount from the atmosphere. Thus their dispersion throughout the Bay is not dependent on aquatic tranport processes. Although it is tempting to link the existence of this regional contamination with well publicized regional biological problem , no link has yet been proven.
Brian P. Bradley and Morrris H. Roberts Jr.
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 crustacean taxa. Mysids, decapods and copepods seem comparable in sensitivity. Of the pesticides, tributyltin, an antifoulant, presents the greatest present or potential hazard. Chlorine, the most widely used oxidant in Chesapeake Bay, is highly toxic to all taxa reviewed, making zooplankton highly vulnerable. Lethal effects can be reduced or eliminated by dechlorination, but sublethal effects may persist.
W. A. Van Engel
That environmental conditions in the Chesapeake Bay are optimal for the blue crab population is suggested by the fact that hard crab landings by Virginia and Maryland watermen accounted for almost 48% of the total of East and Gulf coast landings in 1985. Estimates of total mortality from the egg to the adult stage range from 0.999973 to 0.999996. Commercial fishing removes an additional 0.0000031 to 0.0000251, leaving 0.0000024 to 0.000001 as the rates of removal by other sources. Physical and chemical pollutants, predators, and plants and animals symbiotic with the blue crab are part of the environment that must be acknowledged as actual or potential factors affecting the rates of reproduction, growth and survival, and the behavior and distribution of the blue crab population. The impact of parasites and disease, predation, salinity, temperature, dissolved oxygen, heavy metals, polynuclear aromatic hydrocarbons, and halogenated substances on the blue crab are described . .
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, embryos and larvae are found in the Bay.
Over 70,000 chemical are being manufactured in the United States today. Of the e approximately 50,000 are being produced in excess of 1.3 billion pounds annually.
Carl Hershner and Richard L. Wetzel
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 to meet water quality, erosion control and habitat objectives.
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 and development, predators and diseases and oyster fishery are briefly discussed.
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.
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, Interactions between environmental pollution and disease, and prophylaxis and treatment of their diseases. Importation of foreign oysters (and other shellfish species) and their transfer and transplantation between the coastal regions, provinces, and states of North America have resulted in growing disease problems and a corresponding interest In the parasitology and pathology of the mollusks involved. It has also spawned efforts to control introductions and transfers. Two major diseases have been found to interfere with production or native Atlantic oysters along the Gulf and/or Atlantic coasts of the United States. These are the "Dermo" or "fungus" disease, caused by the apicomplexan protlstan Perkinsus marinus (both coasts) and "MSX" or Delaware Bay disease, caused by the sporozoan Haplosporidium nelsoni (the Atlantic coast-prlncipally in Chesapeake and Delaware Bays). Knowledge of lhese important epizootic-produclng diseases Is reviewed and discussed, along with that or other parasites and pathogen. of molluskan shellfish lo North America, and an extensive References section of the results or recent research on molluskan parasites and diseases is presented.
Micheal E. Bender, Robert J. Huggett, and Harold D. Sloane
The ability to predict the environmental fate and effects of pollutants in the marine environmenits of utmost importance in assessing the hazards posed by a compound's use and/or disposal. Most commonly utilized methods to establish potential environmental effects have involved an assessment with bioassays of a compound's acute and chronic toxicity. For compounds that have the ability to bioaccumulate, the potential dangers from this process must also be determined. A "first cut" estimate can be made by determining the partition coefficients between an organic solvent, usually n-octanol, and water. If this coefficient exceeds 25,000, EPA requires a report of the potential hazard (under the Toxic Substances Control Act), and further study is required. The next step is to expose some likely target animal to the suspected contaminant through food and/or water.
James H. Carpenter and Robert J. Huggett
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, often a legal necessity, for impact studies to be very detailed and specific and to collect reams of data that have no underlying logic and defy generalization or test. This prevents the growth of coastal ecology as a science." It seems interesting and paradoxicaI that the collection of a large amount of data prevents the growth of a particular science, but it seems to be true.
Blue crab mortalities associated with pesticides, herbicides, temperature, salinity, and dissolved oxygen
Willard A. Van Engel
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.
Robert J. Orth and Kenneth A. Moore
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 individual bed of SAV (Stevenson and Confer 1978), while sediment composition and light regime are important factors in controlling the distribution of SAV within regions of the Bay. All species, regardless of the salinity regime, are found in regions of the Bay's littoral zone and are iocated in water less than two to three meters deep (mean low water - MLW), primarily because of low levels of light that occur below these depths (Wetzel et al. 1981).
Life history, ecology and stock assessment of the blue crab Callinectes sapidus of the United States Atlantic Coast - a review
Robert E. Harris
The blue crab is found along the Atlantic coast of the United States from Maine to southern Florida. It is uncommon north of Cape Cod and is most abundant in the Chesapeake Bay where almost half of the United States commercial blue crab landings occur.
The Chesapeake Bay has the largest semi-confined area for blue crab spawning, more nursery area and probably the best mix of environmental conditions for blue crab along the United States eastern coast. In addition, an intensive commercial fishery enables the Chesapeake Bay region to be the area of highest blue crab production.
There are many basic similarities in the life history of the blue crab all along the Atlantic coast. Some differences do occur, however, in timing of some of the life processes, probably due to the different temperature regimes that exist along the coast.
Richard L. Wetzel, Robin F. van Tine, and Polly A. Penhale
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 communities. These investigations created the data base necessary for the development of ecologically realistic simulation models of the ecosystem. Following these initial studies, the research programs in both Maryland and Virginia evolved toward more· detailed analyses of specific factors ~hat potentially limit or control plant growth and productivity. Previous results indicated certain environmental parameters and biological processes that possibly limited and controlled SAV distribution and abundance. Specifically, these included light, nutrients, herbicides and fouling (epibiotic growth). Laboratory and field studies were devoted in the later phases of the CBP-SAV program toward investigating these interactions. This work is among the first studies in North America to investigate light quality as a major environmental factor affecting the survival of sea grasses.
R. Bieri, O. Bricker, R. Byrne, R. Diaz, and et al
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 its origin in scientific project reports listed in Appendix A.
Ann Hayward Rooney-Char and Maurice P. Lynch
Distribution and Hydrodynamic Properties of Fouling Organisms in the Pier 12 Area of the Norfolk Area Station
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.
Dexter S. Haven, Frank O. Perkins, Reinaldo Morales-Alamo, and Martha W. Rhodes
Oysters contaminated in nature depurated fecal coliforms to levels below 50/100 g in 48 hr over a wide range of environmental conditions typical of the lower Chesapeake Bay region. Temperature was found to be the most crilical environmental factor with conditions below 10-12°C having the potential of inhibiting depuration. Coliform clearance did not appear to be correlated with pumping rate or biodeposition activity of oysters. Oysters infected with the pathogens Dermocystidium marinum and Minchinia nelsoni (MSX) depurated as rapidly as uninfected ones. Meat quality and size of oysters likewise did not affect depuration.
Four commercial-size tanks of different designs were found to yield satisfactory results in 48 hr. Water flow rates over the ranges studied and location of trays within the tanks did not influence depuration.
Biodeposits contained high levels of total and fecal coliforms, but their accumulation in the tanks did not have a detrimental effect under the conditions studied.
Pooling oysters during monitoring of' depuration samples was necessary due lo the variation of coliform levels in individual oysters. Samples of 6-8 pooled oysters appeared to be adequate for estimating coliform levels.
The Medium A-1 test was superior to the elevated temperature coliform plate_ (ETCP) procedure of Cabelli and Heffernan for determination of fecal coliforms in oysters.
Robert E. Jenkins
The current list of freshwater fishes known from Virginia stands at 206 species, including 10 that are diadromous and 4 others ranked as freshwater-estuarine. Eight of the freshwater and one of the freshwater-estuarine species were introduced to the state. Several additional strictly freshwater fishes are expected to be discovered. The Virginia freshwater ichthyofauna is relatively rich in species compared with most other states. For example, Maryland and Delaware together have 99 species (Lee et aZ., 1976), West Virginia 151 (Denoncourt et aZ., 1975), Kentucky 201 (Clay, 1975), and North Carolina 195 (Menhinick et aZ., 1974). Some of these totals reflect our adjustments for diadromous and estuarine fishes. The other adjacent state, Tennessee has a much richer freshwater fauna than Virginia. <.....>
Virginia's marine and estuarine fish fauna is characterized by its dynamic nature. Most elements of the fauna are migratory. All are highly mobile. Most are widespread coastally and occur in their preferred habitats in many localities within Virginia and other states. Musick (1972) annotated 208 species of marine and estuarine fishes within Virginia's coastal fish fauna, including 174 marine, 24 estuarine, and 10 diadromous (9 anadromous, 1 catadromous) species. Fourteen (10 diadromous and 4 estuarine) species are shared with the freshwater faunal list.
M. E. Bender, R. J. Huggett, and W. J. Hargis Jr.
Oysters from the James displayed variations in Kepone residue levels related to water temperature and their spawning cycle. Oyster depuralion rates were related to temperature. In summer the "biological half. life" of Kepone in oysters was about one week, while during the winter about 40 days were required for residue levels to decline by 50 per cent. Residues in blue crabs varied as a function of sex, males having considerably higher residues than females. Fin fish levels from the James varied greatly, with residue levels being dependent on species and length of residence for migratory fishes .. Average Kepone residues in freshwater fish species, which are resident their entire Jives, varied from 0.04 to 2.4 μg/g. Long-term resident estuarine fin fish varied less than freshwater species, with mean concentrations between 0.6 and 2.7 μg/g. Short-term resident marine fish species, e.g. American shad and menhaden, exhibited low residues averaging less than 0.1 μg/g, while spot and croaker, which reside in the river for longer periods, bad higher residues averaging 0.81 and 0.75 μg/g respectively.
In the Bay, croaker, spot, trout and flounder all exhibited similar residue patterns showing lower residue levels at stations further up-Bay from the Kepone source in the James River.
Marvin L. Wass
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 Point (Figure 1).
Harold J. Humm
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.
Douglas W. Lipton and Jack G. Travelstead
A seining survey of the fish fauna of the beach zone in the James River, Virginia, was conducted from July to December 1977. Weekly collections were made at 4 stations resulting in the capture of 17,602 individuals representing 36 species. Abundance and diversity were influenced by large catches of schooling and migratory species utilizing nearshore areas as a nursery ground. Freshwater species diversity peaked in August and September, while mesohaline species diversity peaked in July, September, and November. Cluster analysis was used to define 3 freshwater station groups representing warm, moderate, and cool water temperatures, but was not helpful in analyzing mesohaline stations.
Robert T. Doyle, J. V. Merriner, and M. E. Bender
Contamination of the James River in Virginia by the organochlorine pesticide Kepone R prompted depuration studies of commercially important species. Approximately 400 croaker (Micropogonias undulatus) were taken from the James River and placed in Kepone-free York River water. Groups of 20 fish, maintained at ambient temperature, were sampled over time to determine depuration rate. Results suggest that there is no substantial depuration of Kepone by croaker until water temperature exceeds 15 C.
M. Y. Hedgepeth, W. H. Kriete Jr., and J. V. Merriner
Yellow Floy FD-67 internal anchor tags were utilized in an experimental and field study of tag discoloration, tag legibility and fouling organisms. Most tags exhibited some degree of discoloration over time. The rate and extent of discoloration varied between two batches of tags purchased in different years. The legibility of a tag was not affected to a great extent by the degree of discoloration. Legends of some completely discolored tags were still readable. Fouling organisms eroded the vinylite covering and deteriorated the legends of some tags. Bryozoans, barnacles and tunicates were the most commonly encountered fouling organisms. Barnacles were the most erosive of these organisms. Other causes of tag discoloration were believed to be chemical reactions between the vinylite covering and environmental factors such as salt concentration.
J. Howard Kerby and Edwin B. Joseph
Experiments comparing growth and survival of striped bass (Morvne saxatilis) and striped bass female X white perch (M. americana) male hybrids indicated the hybrids were hardier than striped bass under the same experimental conditions. Striped bass exhibited health problems and resulting mortality which were not evident in the hybrids. Overall survival of striped bass in 2 replicate experiments was 42.5% after II months. whereas that of the hybrids was 84.2%. Striped bass and hybrid growth patterns were similar, but striped bass grew somewhat more rapidly than the latter. Mean specific (instantaneous) growth rates were roughly similar throughout the study. with the major differences occurring during the first 4 months. At 17 months of age the mean hybrid fork length was 227.50101 (range. 167 to 282 0101). This length was approximately equivalent to that of wild populations of white perch with 4 to 8 annuli and to that of mid-Atlantic striped bass with 2 annuli, but was substantially less than that of fresh-water and more southern populations. Hybrid length-weight equations were intermediate between those of striped bass and white perch. Salinity experiments demonstrated that both small (mean fork length, 43 mm) and large (mean fork length. 279 mm) hybrids can survive and grow for indefinite periods at salinities of 18 to 25 0/00 with no signs of stress. We believe that the hybrid may be suitable as a supplement to natural populations of striped bass and white perch in estuaries.
William H. Kriete Jr., John V. Merriner, and Herbert M. Austin
Striped bass (Marone saxatilis) were tagged in Virginia beginning in 1968. The 1970 yearclass of striped bass was tagged both in Virginia and New York in 1972. Fish tagged in Virginia were returned from New York to Maine while fish tagged in New York were returned from the Maryland portion of the Chesapeake Bay and the Potomac River. These data indicated that fish migrate from rivers in which they were spawned at different ages and that fish that migrate as 2 year olds remain together as a group until they are 3+ years. Therefore, within the Chesapeake Bay area there are distinct river populations at least until these populations are 3+ years old.
The Men All Singing is a folk history as well as economic. It reaches back almost four centuries to tell of a little-known fishery that shares with cod the vista of our coastal life. Now the last decades of the twentieth century see great changes in all fisheries and our treatment of the waters that give so much of our food.
Changes in salinity structure of the James, York and Rappahannock estuaries resulting from the effects of Tropical Storm Agnes
Paul V. Hyer and Evon P. Ruzecki
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 controlled by the salinity distribution in the Bay. ~ess pronounced stratification maxima occurred in the James about July 6 and August 18 and in the York during August. These events do not appear to be correlated with stream gauge flow records or local precipitation. These events are possible instances of overshooting of equilibrium by the intruding salt water near the bottom.
Marvin L. Wass
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.
C. L. Smith, W. G. MacIntyre, C. A. Lake, and J. G. Windsor Jr.
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, and June 1973 was found to be small in comparison to nutrient inputs.
George C. Grant, Burton B. Bryan, Fred Jacobs, and John E. Olney
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.
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