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Item Light and Submerged Macrophyte Communities in Chesapeake Bay: A Scientific Summary(United States Environmental Protection Agency, 1982) Wetzel, Richard L.; van Tine, Robin F.; Penhale, Polly A.; Virginia Institute of Marine ScienceThe 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.Item Distribution and Abundance of Submerged Aquatic Vegetation in Chesapeake Bay(United States Environmental Protection Agency, 1982) Orth, Robert J.; Moore, Kenneth A.; Virginia Institute of Marine ScienceThe 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).Item Toxic Substances(United States Environmental Protection Agency, 1982) Bieri, R.; Bricker, O.; Byrne, R.; Diaz, R. J.; Virginia Institute of Marine ScienceThis 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.Item Blue crab mortalities associated with pesticides, herbicides, temperature, salinity, and dissolved oxygen(Gulf States Marine Fisheries Commission, 1982) Van Engel, Willard A.; Virginia Institute of Marine ScienceCommercial 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.Item Distribution and Hydrodynamic Properties of Fouling Organisms in the Pier 12 Area of the Norfolk Area Station(EG&G Washington Analytical Services Center, 1980) Diaz, Robert J.; Virginia Institute of Marine ScienceFouling 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.Item Factors Affecting The Distribution And Abundance Of The Blue Crab In Chesapeake Bay(Pennsylvania Academy of Science, 1987) Van Engel, W. A.; Virginia Institute of Marine ScienceThat 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 . .Item Life history, ecology and stock assessment of the blue crab Callinectes sapidus of the United States Atlantic Coast - a review(Gulf States Marine Fisheries Commission, 1982) Harris, Robert E.; Virginia Institute of Marine ScienceThe 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.Item Chesapeake Oyster Reefs, Their Importance, Destruction and Guidelines for Restoring Them(VIMS Press, 1999) Hargis, William J.; Haven, Dexter S.; Virginia Institute of Marine ScienceThe eastern oyster, Crassostrea virginica (Gmelin), can live any place in coastal marine and estuarine waters of the North American east coast offering suitable setting and survival opportunities. It occurs singly or in small clumps scattered widely but thrives best in colonial aggregations which, like those of tropical corals, are truly reefs. The massive self-renewing oyster reefs ("whole banks and beds") reported by early Chesapeake observers have yielded much. Without readily accessible oyster reefs the first English colonists of Jamestown might have starved. Without them the rich oyster industries of later years could never have developed.But oyster reefs benefitted the oysters that built and maintained them as well as the humans using them. The oyster reefs of the Chesapeake region, including those on Seaside, developed during some 7,000-6,000 years of Bay evolution during the current (Holocene) Epoch. Until about 200 years ago reef oyster populations were able to maintain themselves and their reef habitats and withstand the inroads of biological enemies, other natural hazards and increasing harvests. By the late 1800s, Chesapeake public market oyster harvests had peaked and total market harvests and the oyster populations which provided them were in decline. more ...Item Use of Dredged Material for Oyster Habitat Creation in Coastal Virginia(VIMS Press, 1999) Priest, Walter I; Neslerode, Janet; Frye, Christopher W.; Virginia Institute of Marine Science; Virginia Marine Resources CommissionDredging can have a beneficial effect on oyster habitat when the placement of the dredged material is effectively managed to help provide the bottom structure necessary to develop an oyster reef. Construction and maintenance of the Waterway on the Coast of Virginia (WCV) by the U. S. Army Corps of Engineers (Corps) has provided a number of examples of this process, both serendipitous and deliberate. The historical development of reefs that evolved from the random overboard placement of dredged material and the subsequent leasing of these areas for oyster cultivation is reviewed. A monitoring plan for the development of a reef in Swash Bay using maintenance dredging material is also described including pre- and post-dredging hydrographic surveys, surface sediment distributions, and shellfish surveys. After one year, the benthic communities at the recently used placement site, the historical placement site and an unimpacted area in Swash Bay were compared using the Benthic Assessment Method (BAM) to determine short-term impacts. The historical and unimpacted sites had very similar values while the recently used site was somewhat lower. Consequences of continued success in developing oyster reefs in close proximity to a dredged channel are addressed with a suggested management plan that involves rotating the placement among a number of sites. This would allow for the continued maintenance of both the channel and the adjacent oyster reefs.Item Materials Processing by Oysters in Patches: Interactive Roles of Current Speed and Seston Composition(VIMS Press, 1999) Harsh, Deborah A.; Luckenbach, Mark W.; Virginia Institute of Marine ScienceFiltration rates for oysters have typically been measure in still water laboratory experiments and ecosystem-level effects estimated by extrapolation. With the exception of in situ measures of oyster filtration by Dame (1999, Chapter 18, this volume and references cited therein) these estimates have failed to account for the effects of hydrodynamic effects on oyster filtration rates and on physical redistribution of particles. In this chapter we report on a series of experiments conducted in a recirculating seawater flume designed to address the effects of flow speed and seston composition on filtration rates in a bed of oysters. In six separate experiments ninety oysters were arranged in the bed of the flume, flow speed adjusted to one of eight levels (0.65, 1.0, 2.1, 4.2, 6.0, 10.4, 13.7 or 22.0 cm s·1 ), seston added to the flume and particle concentrations upstream and downstream of the oyster bed determined from vertically-arrayed samples. Four experiments investigated the effects of each flow speed on the filtration of a unialgal diet, while two experiments utilized the algal diet in combination with inorganic particles. Control experiments sought to estimate the effects hydrodynamic effects on particle distribution by measuring "filtration" rates over beds of ninety pairs of empty oyster valves. Our findings reveal effects of flow speed and, less evidently, seston composition on particle filtration by oysters. More importantly, our results point to the importance of hydrodynamically-mediated particle redistribution of particles over patches of oysters, and portend sampling difficulties associated with quantifying oyster filtration rates in the field.Item Small-Scale Patterns of Recruitment On A Constructed Intertidal Reef: The Role of Spatial Refugia(VIMS Press, 1999) Bartol, Ian K.; Mann, Roger; Virginia Institute of Marine ScienceTraditional oyster repletion activities have utilized a two-dimensional approach to shell (substrate) deployment to attain maximal coverage in subtidal locations with little consideration for optimal thickness of deployed shell and tidal elevation. Vertical dimensionality may play a vital role, however, in the establishment and persistence of oyster communities. Therefore, a three-dimensional oyster reef was constructed in the Piankatank River, Virginia, and settlement and mortality patterns of oysters were recorded from June of 1993 through September of 1994.Item Oyster Restoration Efforts in Virginia(VIMS Press, 1999) Wesson, James; Mann, Roger L.; Luckenbach, Mark; Virginia Marine Resources Commission; Virginia Institute of Marine ScienceLong-term restoration of the Virginia Oyster resource has been assisted by a series of governmental and regulatory initiatives. Following the 1990 Blue Ribbon Panel the Virginia Marine Resources Commission set as goals that the oyster resources and oyster fishery would be so managed as to achieve (a) no net loss of existing standing stock of the native oyster over the next five years, and (b) a doubling of the existing standing stock of the native oyster over the next ten years. The 1994 Chesapeake Bay Aquatic Reef Plan and Oyster Fishery Management Plan both recommended the creation of 5,000 acres (2024 hectares) of oyster reef habitat during the 1995-2000 period. Practical progress toward this goal has been made through the development of several programs including direct application of substrate (cultch) to extant oyster reefs to facilitate settlement and recruitment, enhancement of reefs of the Seaside of the Eastern Shore by exhumation of buried shell, and construction of elevated reef structures in the Virginia subestuaries of the Chesapeake Bay. Efforts in the James River have included subtidal berm type structures capped with shell and a reef constructed entirely of shell. A shell reef has been constructed in the Piankatank River, and construction of several more is planned. All reefs remain as brood stock sanctuaries. Continuing management is supported by quantitative stock assessment.Item The Marine Algae of Virginia(The University Press of Virginia, 1979) Humm, Harold J.; Virginia Institute of Marine ScienceStarting 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.Item Efficacy of blue crab spawning sanctuaries in Chesapeake Bay(University of Alaska Sea Grant College Program, 2001-01-01) Seitz, Rochelle D.; Lipcius, Romauld N.; Stockhausen, William T.; Montane, Marcel M.; Virginia Institute of Marine ScienceSanctuaries can potentially protect a significant fraction of the spawning stock, and thereby sustain heavily exploited populations. Despite the worldwide use of marine and estuarine spawning sanctuaries, the effectiveness of such sanctuaries remains untested. We therefore attempted to quantify the effectiveness of the spawning sanctuaries for adult female blue crabs (Callinectes sapidus) in Chesapeake Bay. We used baywide winter dredge survey data to estimate the potential spawning stock prior to the major exploitation period, and summer trawl survey data to estimate spawning stock abundance within the Lower Bay Spawning Sanctuary and adjacent Bayside Eastern Shore Sanctuary during the reproductive period. Hence, we were able to approximate the percentage of the potential spawning stock that was protected by both sanctuaries after exploitation. On average, approximately 16% of the potential spawning stock survived to reach the Lower Bay Spawning Sanctuary and Bayside Eastern Shore Sanctuary. Even under a best-case scenario (i.e., crab residence time of 2 weeks), the sanctuaries only protected an estimated 22% of the potential spawning stock, which is well below the percentage recommended by recent stock assessments for sustainable exploitation (28%). In the worst case, a mere 11% of the potential spawning stock survived to reach the spawning sanctuaries. Hence, we recommend a substantial expansion of the spawning sanctuaries, as well as the complementary protection of other life stages in critical habitats, such as nursery grounds and dispersal corridors. Furthermore, traditional fisheries management measures (e.g., effort control) should be used in concert with sanctuaries to thwart impediments to effective implementation of the sanctuaries, such as redirected fishing effort.Item Mycobacterial infections in striped bass (Morone saxatilis) from Delaware Bay(USGS, 2006-01-01) Ottinger, Christopher A.; Brown, J. Jed; Rhodes, Martha; Kator, Howard; Gauthier, David T.; Vogelbein, Wolfgang K.; Virginia Institute of Marine ScienceMuch of what is known of mycobacteriosis in wild striped bass from the mid-Atlantic region of the United States is based on our observations from Chesapeake Bay and its tributaries, where high infection prevalence and lesioned fish are frequently observed. Comparatively, the occurrence and severity of mycobacteriosis in striped bass from watersheds adjacent to Chesapeake Bay are relatively unknown. This study represents the first report on mycobacterial infection in striped bass harvested from two sites in Delaware Bay.Item The Evolution of the Chesapeake Oyster Reef System During the Holocene Epoch(VIMS Press, 1999) Hargis, William J.; Virginia Institute of Marine ScienceThe oyster industries of Virginia and Maryland were based upon adult and juvenile oysters, and their shells, produced naturally on the reefs of the Chesapeake oyster reef system. Without those reefs the billions of bushels of live oysters and shells taken by humans could neither have been produced naturally nor harvested and the valuable social and economic activities derived therefrom would never have occurred. The origin and development of the formerly massive, naturally self-renewing Chesapeake reef system were directly associated with the evolution of the Bay. Its destruction can be linked primarily to the increase of humans around the Bay and beyond and their demand for oysters and shells. Both phases, development and destruction, of reef history have occurred during the last three-quarters to twothirds of the post-glacial Holocene period, around 7,000 years or less. more...Item The ecology of mycobacteria infecting striped bass (Morone saxatilis) in Chesapeake Bay: A research plan(USGS, 2006-01-01) Kator, Howard; Rhodes, Martha; Gauthier, David; Virginia Institute of Marine ScienceThe ecology of mycobacteria in estuarine and marine waters remains poorly understood. The current epizootic in Chesapeake Bay striped bass and newly described pathogens Mycobacterium shottsii and M. pseudoshottsii raise ecological questions that if answered can improve our understanding of the pathogenesis of mycobacteriosis in this fish species.Item Epizootiology of mycobacteriosis in Chesapeake Bay striped bass (Morone saxatilis): Large-scale field survey(USGS, 2006-01-01) Gauthier, David T.; Latour, Robert; Vogelbein, Wolfgang K.; Virginia Institute of Marine ScienceStriped bass in Virginia and Maryland waters of Chesapeake Bay are experiencing an ongoing epizootic of mycobacteriosis. Visceral disease prevalence exceeding 50% has been reported in several locations by various authors, and skin lesion prevalence exceeding 30% has been observed. The high prevalence of skin lesions observed in Chesapeake Bay striped bass is unusual and has not, to our knowledge, been reported previously in wild fishes.Item Epizootic mycobacteriosis in Chesapeake Bay striped bass: What is the fate of infected fish?(USGS, 2006-01-01) Vogelbein, Wolfgang K.; Hoenig, John M.; Gauthier, David T.; Virginia Institute of Marine ScienceStriped bass (Morone saxatilis) in Chesapeake Bay, USA, are currently experiencing an epizootic of mycobacteriosis. Visceral disease prevalence in resident fish exceeds 50% and prevalence of skin ulcers can exceed 30% in some areas. Two primary hypotheses regarding emergence of this chronic bacterial disease propose that anthropogenic stressors constitute important underlying modulating factorsItem Effect of Tropical Storm Agnes on setting of shipworms at Gloucester Point, Virginia(Chesapeake Research Consortium, 1976) Wass, Marvin L.; Virginia Institute of Marine ScienceSurveillance 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.