Research Projects

Provide predictive information for management needs on sediment contamination effects on living resources

Year 1 Objectives: 1) Calibrate the individual Dermo and MSX disease models for the entire range of Chesapeake Bay, 2) Undertake analysis of disease, oyster and environmental data sets for use in the host-pathogen models, and 3) Develop and calibrate the combined two pathogen-oyster model for Chesapeake and Delaware Bays Year 2 Objectives: 1) Perform site-specific simulations with the two pathogen-oyster model for selected Virginia, Maryland and Delaware sites, 2) Undertake model refinements and additional calibration and verification as needed, 3) Test model robustness by extension to Long Island Sound, NY and northeastern U.S., and 4) Summarize, report and disseminate information on the two pathogen-oyster model and the results of simulations with this model.

The objectives of the Research Plan are (1) to demonstrate the efficacy, feasibility and environmental safety of Cutlerite as a treatment for ballast water, and (2) to obtain the experimental data necessary to satisfy EPA requirements for registration of Cutlerite as a commercial biocide. The Research Plan includes three separate components: 1. Aquatic toxicology assays, to measure the effective concentrations of Cutlerite against potential aquatic nuisance species; 2) Environmental fate analyses, to measure the biodegradation of Cutlerite; 3) Dockside and Shipboard trials, to measure the performance of Cutlerite under real-world conditions.

This program will develop and implement a virtual clearinghouse for information on aquaculture emanating from a variety of key federal and nonfederal sources. The Network of Aquaculture Information Services (NAIS) will develop a world wide web based system to provide 24 hour access to a variety of central databases, resources as well as contact information relevant to active and potential user groups involved with aquaculture. The project will link expertise through within Maryland Sea Grant and the NOAA Central Library with ongoing efforts within the Illinois-Indiana and Delaware Sea Grant Programs.

There is presently an increasing effort to plant specific pathogen-free (SPF) seed oysters on beds in the upper low-salinity reaches of many estuarine rivers to manage around disease by avoidance. But simply planting SPF seed in these areas may not prevent subsequent infections by Perkinsus marinus (dermo) if resident oyster populations harbor and transmit this disease. Whether dermo disease transmission and mortalities among planted SPF seed occur may depend on temperature, salinity and the prevalence and intensity of P. marinus infections in resident native oyster populations (Burreson and Ragone Calvo 1996). Due to limited availability of SPF seed oysters, it is imperative that they be deployed by strategies which maximize their resource enhancement return.

The proposed research will (a) evaluate the frequency of transfer for microorganisms that are serious pathogens of humans and commercial fishery species and (b) assess the potential significance of ballast-mediated transfer in the epidemiology of infectious diseases. This work is critical in identifying the risks associated with ballast water transfer, providing key data for developing necessary management strategies for organisms of particular concern. Results from this research will be published in peer-reviewed international journals and presented to scientific and management communities. The data resulting from this project are especially relevant and timely to the national and international efforts to limit the risk of ballast-mediated transfer and invasion.

Using paleoecological techniques, to reconstruct the history of the trophic structure of the Chesapeake Bay over the past 2000 years, in order to compare the effects of changes in climate during the approximate 200 year Medieval Warm Period which occurred about 1000 years ago and the Little Ice Age which lasted for a few centuries following the warm period, with anthropogenic changes including deforestation, agriculture and urbanization which have occurred over the past two to three centuries.

To assess degradative enzyme activity of Alteromonas 2-40 (2-40) by: a) Assaying degradative activity in sole and multiple carbon sources (substrates), e.g. combinations of agarose, chitin and alginate (a condition 2-40 is likely to encounter in nature); b) Assessing enzyme activity of cells, grown in combinations of these complex carbohydrates in time course and as to culture fraction (e.g. supernatant, membrane and whole cells).

This research will use ocean color data from satellite and aircraft instruments in data assimilation models to: quantify seasonal and interannual variability of phytoplankton biomass and productivity in the Chesapeake Bay with unprecedented spatial and temporal resolution; use in combination with a coupled biological and physical model of Chesapeake Bay and the outflow plume to interpolate between observational periods, extend these observations in a third - vertical - dimension, and provide estimates of production and biomass of higher trophic levels.

Optimize and standardize the most efficient techniques for screening Chesapeake Bay oysters for Cryptosporidium parvam contamination: a) improve the quality of the harvested shellfish, b) quickly, accurately, and economically identify contaminated oyster bars for controlled harvesting, c) determine infectivity to humans of C. parvam oocysts recovered from oyster tissue, d) determine whether oysters can be used as bioindicators of water contamination by C. parvam e) protect human health by prevention of foodborne cryptosporidiosis. To assess the role of environmental components, i.e., wastewater discharges, waterfowl presence, and cattle farm run-offs in contamination of the Chesapeake Bay with C.

The objective of this study is to assess the fate, bioavailability and transport of metals and metalloids in dredge spoils applied to wetlands. Specifically, we will examine six of the Chesapeake Bay Program Toxics of Concern (Cu, Pb, Cd, Cr, Hg, As) in a restored marsh that has previously received dredge spoils (Kenilworth Marsh) and in a control marsh (Dueling Creek) within the Anacostia River. We will also examine two metals that serve as models for particular modes of redox cycling (Fe, Mn).

To measure depositional fluxes of sediment and sediment-water exchange rates of trace metals in order to develop a sediment budget for Baltimore Harbor, examine rates and locations of high rates of metal deposition and develop sediment-water exchange procedures for metals and to determine if such exchanges are important to the biota and overall metal budgets.

To produce immunologically and biologically active recombinant striped bass GtH-I and GtH-II, and to develop an enzyme-linked immunosorbant assay (ELISA) for striped bass GtH-I. To use and optimize a novel and generic recombinant DNA approach for expressing biologically and immunologically active gonadotropins of fish, in view of enabling studies on their reproductive endocrinology.

The overall objective of this project is to quantify the bioaccumulation and food web dynamics of hydrophobic organic compounds (HOCs: primarily PCBs, chlordanes and DDTs) in Anacostia River via exposure through the water column (e.g. suspension feeders, predators) and the benthic (e.g. deposit feeders, suspension feeders) communities in the sediments of the river. Specific objectives are to determine the contaminant level and season variations in important food sources to benthic and pelagic fish in the river, and determine the inter-relationships among primary producer-consumer-predator using multiple techniques including stable isotopes, gut content analysis, and PCB and chlordane concentration and fingerprinting analysis.

Our overall objective is to characterize the transfer, dynamics, and potential to invade for microbial communities associated with ballast water of ships. More specifically, our study will: Measure the abundance, biomass, growth and carbon-source utilization patterns of bacteria that arrive in ballast water as a function of source region, voyage duration, and specific water characteristics (e.g., temperature, salinity, macro-plankton abundance and diversity); Measure changes in microbial community characteristics of ballast water during voyages, including the effects of current ballast management practices on these communities; Measure the specificity and functional relationships between Vibrio spp.

This project seeks to assess, through structured interviews and normative and policy analysis, the prospects for preserving the livelihoods and communities of watermen under a regulatory regime intended to protect natural resources and rural landscapes. The research would examine and evaluate the extent to which laws and regulations designed to conserve resources, prevent sprawl, and preserve rural landscapes can promote the viability of traditional fishing communities. It will also analyze the regulatory environment in which watermen operate to evaluate the extent to which it promotes or inhibits the survival of their communities.

We propose to examine the coupled problems of fine-scale atmospheric modeling, estimation of air-sea fluxes, and modeling of surface wave fields in Chesapeake Bay, using state-of-the-art numerical procedures. The immediate goals of this study are to improve our understanding of and ability to estimate air-sea fluxes in Chesapeake Bay as they are affected by wind-waves, and to improve surface wave estimates as they are affected by the quality and resolution of wind fields. Ultimately, NOAA/ARL hopes to reduce uncertainties in the atmospheric deposition estimates that it provides as a part of its mission, while our goal at HPL is to move towards a modeling system capable of operational wave forecasts for Chesapeake Bay.

The primary objectives of this proposal are to apply a new direct measurement technique for denitrification to: examine approaches to determining system-wide denitrification estimates in the Choptank River subestuary and determine if oligohaline marshes are important sites for estuarine denitrification. Denitrification will be compared to N input terms available for this subestuary, as well as N sinks including marsh N storage and burial.

This proposed research will continue our efforts to 1) characterize the seasonal changes in the composition of dissolved organic nitrogen (DON) and dissolved organic carbon (DOC) along the axis of Chesapeake Bay, both in terms of specific compounds and molecular weight distributions; 2) determine how much DON and DOC is biologically available to bacteria and phytoplankton in short-term assays and mesocosm studies; 3) compare the rates of supply with estimates of cell size and proportion of active cells.

The objective of this research is to use ocean color data from aircraft remote sensing to determine the distribution of chlorophyll in Chesapeake Bay. We will use a combination of the data from aircraft overflights with two instruments, the Ocean Data Acquisition System (ODAS) and the SeaWIFS Aircraft Simulator (SAS III), with those from shipboard and satellite studies to assess the relationship of principal forcing functions in the Bay to seasonal and interannual variations in phytoplankton abundance. A series of 25-30 flights is proposed for 1997, spanning Iate February through October.

To continue quantification of the impact of the Baltimore/Washington urban area on atmospheric depositional fluxes to the northern Chesapeake Bay through a consistent long-term sampling program at urban and down-wind sites; To, through the release of purposeful tracers of diesel soot exhaust, track the urban plume and characterize size distributions and deposition of combustion-derived aerosol particles; To determine, through intensive sampling programs under winter and summer conditions, the magnitude and variability of atmospheric and surface water concentrations, and of estimated gas exchange rates, or semivolatile organic contaminants and mercury species.

Our overall program objective is to determine the molecular and genetic basis for the factors which influence the Perkinsus marinus-Crassostrea virginica relationship by enhancing the disease process. For this purpose, we have established methodology tor cloning several potential virulence factors in P. marinus and are currently investigating genetics, regulation, and the biochemical aspects of specific factors that relate to specific host recognition, evasion of host defenses, proliferation and pathogenesis. However, basic questions, particularly concerning the parasite's genomic structure and diversity, remain unanswered.

The overall goal of this research is to measure the patterns of delivery and viability of species transferred among U.S. ports in the ballast water of domestic ship traffic. We propose to measure directly the volume of ballast water delivered to selected Atlantic ports from other domestic ports, the abundance and diversity of organisms associated with that ballast water, and the survival of these organisms during transit and upon arrival.

Our current proposal is focused on continuing the application of our quantitative molecular (PCR) diagnostic techniques for practical field purposes regarding the etiology of this oyster disease in the Chesapeake Bay. This includes the identification of P. marinus strains (Types I and II), Perkinsus species and the certification of disease-free oyster seed. The validation of our PCR-based diagnostic assay and a comparison of its performance with the fluid thioglycollate assay (FTM) revealed not only that the PCR-based diagnostic assay is species-specific and far more sensitive than FTM, but that FTM is not specific for P. marinus FTM detects as positive other Perkinsus spp present in the Chesapeake Bay of yet undetermined virulence for Crassostrea virginica.

To identify the basis of P. marinus pathogenicity to C virginica the following host-parasite interactions will be quantified in P. marinus susceptible and -resistant bivalves: phagocytosis and antimicrobial activity, effects of cellular and serum factors on parasite replication, and the production of host immunoregulatory molecules by P. marinus The in vivo effects of b-glucan, a stimulator of antimicrobial activity, administration will be evaluated on the progression and lethality of dermo disease.