Grantee Research Project Results
2004 Progress Report: Phytoplankton Community Structure as an Indicator of Coastal Ecosystem Health
EPA Grant Number: R828677C001Subproject: this is subproject number 001 , established and managed by the Center Director under grant R828677
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: Organotypic Culture Models For Predictive Toxicology Center
Center Director: Rusyn, Ivan
Title: Phytoplankton Community Structure as an Indicator of Coastal Ecosystem Health
Investigators: Paerl, Hans , Luettich Jr., Richard A. , Pinckney, James L. , Noble, Rachel T.
Current Investigators: Paerl, Hans , Luettich Jr., Richard A. , Pinckney, James L. , Valdes, Lexia M. , Noble, Rachel T. , Wyrick, Pamela , Fries, Steven
Institution: University of North Carolina at Chapel Hill , University of South Carolina at Columbia
Current Institution: University of North Carolina at Chapel Hill
EPA Project Officer: Packard, Benjamin H
Project Period: March 1, 2001 through February 28, 2003
Project Period Covered by this Report: March 1, 2003 through February 28, 2004
RFA: Environmental Indicators in the Estuarine Environment Research Program (2000) RFA Text | Recipients Lists
Research Category: Ecological Indicators/Assessment/Restoration , Water , Aquatic Ecosystems
Objective:
The objective of this research project is to develop broadly applicable, phytoplankton-based indicators of estuarine and coastal ecological condition and link these to nutrient and physical-chemical forcing features and remote sensing analyses of water column optical properties.
Progress Summary:
This subproject of the Atlantic Coast Environmental Indicators Consortium (ACE INC) has been operational since April 2001. All aspects of the proposed work plan are in place and coordinated with ongoing water quality and habitat monitoring programs on the Neuse River Estuary (NRE); CISNet and ModMon (http://www.marine.unc.edu/neuse/modmon); Exit and a ferry-based water quality monitoring program for the NRE and Pamlico Sound (http://www.ferrymon.org) Exit . These programs have served as the backbone for the collection of nutrient, photopigment (chlorophylls and carotenoids), productivity, water optical property turbidity, and physical data needed to characterize the structure, function, and environmental controls of indicator phytoplankton communities comprising the base of the estuarine food web. We have been collecting comprehensive diagnostic (of phytoplankton community composition) photopigment samples that will serve to establish a baseline of phytoplankton community composition against which we will be able to gauge trophic state and ecological change in response to a wide variety of environmental forcing features, including nutrient inputs, salinity (reflecting freshwater inputs and residence time), water clarity and other optical properties, zooplankton grazing, and toxic substances. We also have been collecting in situ hydrographic, dissolved oxygen (DO), and water velocity data to allow calculation of the residence time in the system.
Using Phytoplankton Photopigments To Assess Estuarine Ecological Condition and Change
Diagnostic photopigments (chlorophylls and carotenoids) are being developed and deployed as indicators of the phytoplankton taxonomic groups mediating estuarine primary production, harmful blooms, water quality food web dynamics, and overall ecological condition (Figure 1). These indicators are in use in water quality and habitat monitoring programs on the NRE (ModMon), a ferry-based water quality monitoring program for the NRE and Pamlico Sound, the Chesapeake Bay Program ( http://www.chesapeakebay.net) Exit , and ongoing water quality assessments in Florida Bay, the Gulf of Mexico, and other estuarine and coastal systems. These indicators serve as verification and calibration data sources for remote sensing of estuarine phytoplankton biomass and composition, enabling researchers and managers to scale up to whole ecosystem assessments of productivity and ecological condition. Lastly, these indicators are being used to identify and distinguish human inputs (e.g., nutrient enrichment) from climatic stressors affecting water quality and habitat condition.
Figure 1. Roles of Diagnostic Photopigments as Indicators of Ecosystem Productivity and Plant Community Composition in Response to Physical-Chemical Stressors in Estuarine and Coastal Waters
Ecological Effect/Impact. Phytoplankton and associated physical-chemical indicators that are being developed and applied in this subproject have proven useful and applicable for evaluating ecosystem and regional responses to a variety of environmental stressors, including nutrient loads, changes in hydrologic characteristics, large scale fronts, and major storms, including hurricanes. In addition, they offer great promise as a data source for verification and calibration of remote sensing of plankton production and composition for a range of estuarine and coastal water bodies nationally. These indicators are now part of unattended water quality monitoring of estuaries and coastal sounds (Paerl, et al., 2003; Niemi, et al., 2004). For example, water samples, from which these indicators are measured, are being collected using ferries to characterize the large-scale impacts of Hurricane Isabel (September 2003) on the Pamlico Sound.
Environmental Application. Current applications include the use of diagnostic pigment (e.g., chlorophyll α [Chl-α]) concentrations as criteria for meeting allow total maximum daily (nutrient) loads (TMDLs), as early warning indicators of harmful (toxic, hypoxia-generating) algal blooms, turbidity, and designations of nutrient-sensitive waters. Analyses and interpretation of photopigment data in ongoing long-term monitoring programs in major estuarine and coastal systems (Chesapeake Bay, Pamlico Sound, Narragansett Bay, Long Island Sound, Galveston Bay, Florida Bay) are clarifying relationships between the abundance of specific phytoplankton taxonomic groups and various estuarine chemical and physical stressors. Because of the non-linear and complex associations between biological, chemical, and physical variables, we are using more robust data analysis procedures, including neural network analysis, to establish quantitative associations between these variables in space and time, which will help complement the U.S. Environmental Protection Agency’s (EPA) regional assessments of estuarine and coastal water/habitat quality (e.g., Environmental Monitoring and Assessment Program [EMAP]).
The effect of one of these chemical-physical factors, river flow, on phytoplankton abundance and community structure has been studied extensively in the NRE-Pamlico Sound continuum, North Carolina (NRE-PS), and in the Chesapeake Bay, Maryland/Virginia (CB). Both systems are influenced to a great extent by freshwater inflow from the Neuse and Susquehanna rivers, respectively, and by the resulting changes in water residence time and nutrient availability.
Phytoplankton biomass and community structure in the NRE-PS was profoundly affected by changes in hydrology that resulted from droughts and/or large pulses in river flow associated with seasonal increases in rainfall or with tropical storms and hurricanes. This was especially evident at the two endpoints of the study area, in the Upper NRE and the SW PS and SE PS regions. Overall, elevated river flow rates were associated with reduced phytoplankton biomass and group-specific algal biomass in the Upper NRE region. Downstream of the Upper NRE, the reverse effect was observed as total phytoplankton biomass and the biomass of chlorophytes, cryptophytes, cyanobacteria, diatoms, and dinoflagellates were higher during conditions of elevated river flow rates. Conversely, during reduced river flow conditions, phytoplankton biomass was higher at upstream locations, where nutrients are less limiting for phytoplankton. Dinoflagellates were especially reduced in abundance during periods of elevated river flow and reduced water residence time in the upper NRE. Dinoflagellates appear to be both sensitive and ecologically relevant indicators of changes in hydrology in the Upper NRE, as they are consistently more abundant during periods of long residence time when flushing rates are minimal.
These trends suggest that phytoplankton were physically transported downstream during conditions of elevated river flow, an observation similar to that observed in the CB. With recent predictions of increased tropical storm and hurricane activity, the elevated rainfall and river flow rates associated with these disturbances may increase phytoplankton biomass in the currently oligotrophic to mesotrophic regions of the estuarine continuum, especially in the PS. Increases in river flow rates can be used as an indicator of reduced biomass of all taxonomic groups in the Upper NRE and increased biomass of all groups downstream of this region. The reverse applies to reduced river flow rates.
Seasonal phytoplankton community responses to changes in river flow rates were examined and compared between the NRE and the CB. In both systems, the resulting variability in water residence time strongly influenced seasonal and longer-term patterns of phytoplankton biomass and community composition (Paerl, et al., 2005). In the CB, diatom abundance was increased during high flow years (short residence time conditions), regardless of season, when compared to low flow years. Contrary to the CB, diatoms in the NRE were reduced in abundance during high flow years. This discrepancy could possibly be the result of substantially reduced water residence times in the CB (1 to 3 weeks) when compared to the NRE (2 weeks to 2 months). In addition, the native phytoplankton composition that characterizes these two systems is different. Diatoms are generally predominant in the CB, whereas all five taxonomic groups are typically found in similar proportions in the NRE (~20%). With the exception of winter, dinoflagellates were more prevalent during low flow years in the NRE and in the CB (spring months). This phytoplankton group seems to have greater abundance during these increased residence time conditions. Because river flow is minimal during the summer, river flow rates have less of an impact in promoting dominance by either diatoms or dinoflagellates in both systems. In contrast, cyanobacteria tend to be most abundant during the summer in both systems, when distinction between low and high flow is minimized. In the NRE, all phytoplankton groups, except summer cyanobacteria populations, showed decreased abundance during elevated flow years when compared to low flow years. On a seasonal basis, changes in flow regimes co-occur with changing irradiance and temperature patterns. In addition, zooplankton, benthic invertebrate (shellfish), and herbivorous fish (e.g., menhaden) grazing influences phytoplankton abundance and dominance, thus creating a complex set of interactions with residence time that control phytoplankton community structure. These results indicate that physical-chemical forcing features strongly influence estuarine phytoplankton dynamics mediating eutrophication.
Functional group diversity is an integrative measure of both the abundances of individuals within a group and the number of groups in the sample. Biweekly phytoplankton group diversity values were calculated for the NRE over period using Chem-Tax derived group abundances and expressed in units of Chl-α. Linear regression analysis showed a significant (p=0.011) increase in group diversity over this period and suggests that water quality conditions in this estuary may be slowly improving. This is one example of how functional group diversity indices may provide a useful metric for quantifying ecosystem-scale community dynamics. In addition, this approach allows for a non-parametric cross-system comparison of important ecosystem properties.
Physical and Chemical Assessments Coupled With Biological Indicators
We are collecting in situ DO, stratification, turbidity, Chl-α and vertical mixing profiles in the NRE and CB to help determine these critical parameters. These measurements complement long-term (> 10 year) databases on DO values along the axes of these estuaries.
Ecological Effect/Impact. These data allow an assessment of the vertical distribution of algal biomass in the water column. During low wind conditions (e.g., less than 10 m/s), NRE data show a persistent daily vertical migration of the Chl-α maximum, presumably in response to ambient light conditions. At higher wind speeds, the water column becomes well mixed and turbid because of resuspended bottom material. This information is critical for interpreting data from discrete water column samples and from near-surface sampling using remote sensing platforms. The more than 10 years of DO data along the lengths of both estuaries are being processed to determine long-term trends in DO levels and oxygen consumption that can be compared to individual years in these and other systems.
Environmental Application. State and federal watershed managers in North Carolina and elsewhere use DO and Chl-α values as criteria for TMDLs in coastal systems. The above data will help provide a context for interpreting these data and for comparisons with other systems.
Bacterial and Viral Indicators of Ecosystem Condition
This is a multi-tiered effort that includes development of a variety of microbial level indicators of ecosystem condition. Viruses are being developed as probes of specific phytoplankton and bacteria species. If successful virus-host systems can be isolated in the laboratory setting and propagated viruses can be fluorescently tagged and used in natural samples to probe for their host species in natural waters. We also are pursuing study of native and non-native bacterial indicators and pathogens (such as enterococci [ENT] and V. vulnificus) in relation to hydrological variables, Chl-α, salinity, turbidity, total suspended solids, phytoplankton community composition, bacterial growth rates, inorganic and organic matter, particle load and distribution, stormwater loading, and viral and bacterial abundance as evidence of ecosystem disruption. Native bacterial species, such as V. vulnificus, are powerful indicators of public health risk for those using the waters for recreation and for food .
Vibrio bacteria are present throughout the NRE. There is a strong seasonal variation in total culturable Vibrio species, which is supported by findings of previous research (Brasher, et al., 1998; Motes, et al., 1998; Pfeffer, et al., 2003; Randa, et al., 2004). Peak numbers of culturable Vibrio species are reached in the summer months and decrease precipitously in the winter, at some stations dropping below detectable levels. In general, bottom waters tend to have higher total Vibrio counts than surface waters for any given station. This is likely influenced by the increased salinity found in bottom waters, but we also are examining other parameters, including nutrient status, particle loading, turbidity, and DO.
A key environmental variable correlated with Vibrio populations is salinity. It is well known that Vibrio species have varying degrees of tolerance to different salinities (Motes, et al., 1998; Randa, et al., 2004; Pfeffer, et al., 2003). We have assessed the relationship between Vibrio species density and Chl-α and have found no statistically significant relationship. During summer conditions in the NRE when cold temperatures are not a limiting factor, salinity becomes a key variable, and total Vibrio counts increase with increasing salinity. Our data show that salinity is an important predictive factor for Vibrio species growth, and the upper salinity tolerance for Vibrio species is not reached in our sampling area within the NRE. This finding that salinity is the main predictor, and that temperature seems to play a much reduced role, is different than the findings by Gulf of Mexico researchers. These findings could have important implications for successful predictive modeling of V. vulnificus, particularly in temperate climes.
The Noble laboratory is developing quantitative PCR (QPCR) assays for the rapid detection of Vibrio bacteria. Currently, Taqman assays for V.vulnificus and V.parahaemolyticus, based on published primer-probe sets (Panicker, et al., 2004b; Iijima, et al., 2004), have been optimized and used to identify cultured Vibrio isolates from the NRE. These assays also are being used to identify V.vulnificus and V.parahaemolyticus from archived bacterial filters from previous sampling in 2004. V.vulnificus has been identified at surface and bottom samples at several sites in the NRE. Further work is being done to develop these methods into quantitative assays, including work on internal controls.
In addition, development of a new QPCR assay to detect total Vibrio populations is underway. Primers and probes will focus on a region of 16S rRNA that is specific to Vibrio species and shows strong homology among a wide range of Vibrio species in east coast estuaries (Thompson, et al., 2004). We aim to design a multiplex assay that measures total Vibrio as well as specific Vibrio species of public health importance, including V.vulnificus. A QPCR multiplex will provide a rapid, more complete picture of the ecology of Vibrio the NRE system and quantitative information on pathogenic Vibrio species. Finally, we are interested in developing assays for specific pathogenic strains of V.vulnificus to better predict public health impacts (Panicker, et al., 2004a).
Ecological Impact/Effect. Several of the above mentioned tools will be used as direct indicators of ecosystem disruption. Current research in the Noble laboratory is being conducted to develop virus-host systems. We have successfully isolated three bacteriophage-bacteria systems that can be used to probe natural samples for the presence of specific bacterial species. Isolation research for further systems is being conducted on bacteriophage, cyanophage, and algal viruses.
Bacterial indicators, such as ENT, are being used as direct indicators of the impacts of stormwater runoff and other pollution contributions to the NRE-PS, as they are generally not native to the estuarine environment. Monitoring of fecal indicators in the NRE has revealed dynamics in ENT in surface waters. When high levels of these organisms are present, most often concentrations are highest at the freshwater end (Station 0) of the NRE and decrease downstream, demonstrating inputs of allochthonous bacteria from stormwater. Furthermore, these bacteria are direct indicators of the presence of fecal contamination in the estuary. Qualitatively, levels of ENT do appear to increase during wet periods, in particular during May and September of 2004. Ongoing research is focusing on development of an understanding of the relationships among the presence of fecal indicator bacteria (such as ENT, Escherichia coli), other bacterial pathogens of concern (Vibrio species), indicators of large scale anthropogenic perturbation (Microcystis and other phytoplankton blooms), and environmental parameters.
Environmental Application. Useful applications of the developed technology include use of viral and bacteria indicators and pathogen concentrations as criteria for meeting allowable TMDLs in estuarine waters. Novel molecular methods, such as QPCR, are being developed (in conjunction with Rich Haugland at the EPA National Environmental Research Laboratory) as rapid warning systems for the presence of pathogenic bacteria and viruses that represent serious public health risk. The molecular methods, in conjunction with a suite of traditional culture based methods and hydrology parameters, allow us to assess the impact of large-scale storm events, including wind, rain, and resuspension, on mid-Atlantic estuaries. The molecular methods also offer a rapid means to assess the presence of potentially dangerous phytoplankton, bacterial, and viral species, offering a viable means for tracking sources of pollution into the estuary. Research on the presence of V. vulnificus in the NRE is being conducted in collaboration with the North Carolina Department of Environment and Natural Resources (NC-DENR) Harmful Algal Blooms Program as part of a growing concern regarding the incidence of wound infections as a result of V. vulnificus infection along the coasts of the nation.
Training and Educational Development
Recently, the Carolina Environmental Program’s field semester at the University of North Carolina-Chapel Hill’s Institute of Marine Sciences (http://www.cep.unc.edu/level_2/field_sites.html) Exit has been a prime user of ACE INC-generated indicator data and applications. In addition, project results have been used to train middle school and high school teachers and students. We are developing FerryMon as public outreach and educational component to demonstrate the use and application of ACE INC indicators for the Pamlico Sound. Water quality and habitat information will be provided via our interactive Web site in user-friendly formats (such as The Weather Channel) for use in the classroom (kindergarten through university), public information (e.g., ferry kiosks, informational centers, museums), recreational users, stakeholder groups, and interested citizens worldwide. Web sites also have been used to instruct technicians and data managers.
Outreach Activities
Drs. Paerl, Luettich, and Noble are involved in a variety of statewide and national scientific advisory and educational activities. These include serving on NC-DENR’s Technical Advisory Committee (Luettich), the North Carolina Department of Water Quality’s TMDL modeling group (Luettich), the North Carolina Water Resources Research Institute’s Technical Committee (Paerl), the Albemarle-Pamlico Sound National Estuary Program (NEP) Technical Advisory Committee (Paerl), NC-DENR’s Stormwater Outfall Rules Steering Committee (Noble), Advisor to the Shellfish Sanitation Section of NC-DENR (Noble), the NC Environmental Management Commission (Paerl). They also provide technical and evaluative advice for a variety of stakeholder groups, including the Neuse River Foundation, the Pamlico River Advisory Board, the Wilson Bay Advisory Committee, and the Neuse Basin Council of Municipalities. Nationally, Dr. Paerl has been involved in an advisory role in the EPA-Chesapeake Bay Program (Chlorophyll water quality criteria team), the Tampa Bay NEP, the Narragansett Bay Program, the Florida Bay Technical Advisory Committee, the Gulf of Mexico Hypoxia Peer Review Panel, and the American Society of Limnology and Oceanography Policy Committee. Noble has been involved in the National Aeronautics and Space Administration Advanced Environmental and Microbial Control Panel and is an American Society for Limnology and Oceanography representative to the National Water Quality Monitoring Council.
The Principal Investigators are sharing technological developments and evaluative approaches/tools with scientific and agency (state-, federal- and international-level) colleagues, as well as public educational institutions, media, and resource (i.e., fisheries, tourism) managers. Examples of the utility, informational value, and application (scientific, management, and public education) of data thus far obtained can be found on the ModMon and FerryMon Web sites.
Contributions to State of Knowledge
The pigment-based and associated physical-chemical indicators that are being developed and applied in this component project have already proven useful and applicable for evaluating ecosystem and regional responses to a variety of environmental stressors, including nutrient loads, changes in hydrologic characteristics (e.g., salinity, circulation), large-scale frontal passages (i.e., Northeasterners), and major storms, including hurricanes (Paerl, et al., 2001, 2003, 2004; Niemi, et al., 2004). In addition, they offer great promise as a data source for development, verification, and modification of remote-sensing of plankton production and community structure of a range of estuarine and coastal water bodies regionally and nationally (Paerl, et al., in press; Lunetta, et al., in preparation).
The QPCR based assays in development through the Noble laboratory have significance for both the recreational and shellfish harvesting water management agencies, as they have the potential to be used to generate useful results for management of these waters within hours, rather than the day-long time frame needed for currently used membrane filtration and multiple tube fermentation analyses that are routinely conducted. The assays are being developed in collaboration with EPA and Cepheid, Inc.
Future Activities:
Using Phytoplankton Photopigments To Assess Estuarine Ecological Condition and Change
We will calculate the functional group diversity index for other estuaries to facilitate cross-system comparisons and to develop a baseline diversity value for different types of estuarine ecosystems.
Physical and Chemical Assessments Coupled With Biological Indicators
Our results to date have provided key information for interpreting remote sensing data, as well as for determining when the system becomes vertically well-mixed. Our next challenge is to extend this empirical information into a robust modeling framework. To do this, we have been working to quantify mixing rates during our deployments. This effort is complicated considerably by the simultaneous presence of surface waves (that only cause mixing in the near surface zone when breaking occurs) and turbulent motions (that cause mixing throughout the water column). Thus, the critical step in this effort is to separate the motions made by the waves and turbulence. We have achieved preliminary success making this separation by subtracting along beam velocities from a bottom-mounted Accoustic Doppler Current Profiler. This novel technique brings our turbulence measurements well in line with other ways of estimating turbulence conditions (e.g., wind stress as computed from wind speed or bottom stress as computed from near bottom drag). We will continue to examine the general validity of this method during other deployment periods and then work to include this in a model of the system.
Bacterial and Viral Indicators of Ecosystem Condition
Postdoctoral associate J. Stephen Fries has introduced an additional means for monitoring and diagnosing the dynamics of algal and bacterial populations in the NRE. A Coulter counter is now being used routinely on water samples to describe the sizes of particles in suspension. These particles include algal populations in surface waters, runoff particles throughout the water column, and resuspended sediments in bottom waters. With reference to the algal populations, the particle size results provide a quick means for detecting large numbers of cells within a certain size range. Locations in the estuary and size of cells assist us in our pursuit of rapid detection of blooms and the rough identification of the specific algal group responsible. Looking at the total particle volume and Chl-α concentrations in surface waters reveals a strong relationship supporting the general conclusion that the Coulter analyses are providing information about total algal biomass, as well as sizes. These conclusions will eventually be correlated with more specific means of species identification (e.g., microscopy, pigment analyses). In combination, these monitoring practices provide an in-depth look into algal dynamics in the NRE.
Overall Subproject Activities
Several indicators developed in this subproject are now routinely employed in state and federal agency water quality and habitat monitoring programs examining relationships between external stressors (e.g., nutrient enrichment, sediment and toxic inputs, tropical storm and hurricane impacts) and phytoplankton production/community structure responses. We are working with these agencies to extend the use and application of photopigment-based indicators as criteria for TMDLs of nutrients, specifically nitrogen (NRE and Pamlico River Estuary, North Carolina, and numerous riverine sub-estuaries [Patuxent, Choptank, Potomac] of the Chesapeake Bay).
Because of the complex interactions between biological, chemical, and physical variables, researchers and managers using these indicators need to use more robust data analysis procedures, including remote sensing and neural network analysis, to establish quantitative associations between nutrient and hydrologic stressors and phytoplankton community responses in time and space. To meet these requirements, aircraft-based SeaWiFS remote sensing data from flyovers of CB and PS are being coupled to diagnostic pigment analyses to enable investigators to scale up assessments of nutrient and hydrologic (freshwater discharge) controls on phytoplankton production and bloom formation for the entire estuary at monthly and seasonal intervals. This added spatial-temporal coverage will greatly enhance EPA’s regional assessments of estuarine and coastal water/habitat quality (e.g., EMAP).
To further expand spatial and temporal coverage and enhance linkage to remote sensing, photopigment indicators are being deployed on unattended monitoring platforms, including moorings, channel markers, and ferries. We are expanding our activities and applications in these areas. For example, in the university-state partnered ModMon Program, in-stream vertical profile sampling equipment will be employed in 2005 with collectors (ISCO, Inc.) capable of close time-interval collection of photopigment samples. This will enhance our ability to monitor, model, and predict diel vertical displacement of phytoplankton communities to more accurately and realistically assess compliance and exceedance of the TMDL (which is based on Chl-α) for this system by the use of remote sensing of surface waters. Based on these measurements, algorithms linking phytoplankton vertical migration patterns to field and remote sensing assessments of surface Chl-α concentrations are being developed to most accurately gauge compliance.
Use of photopigments as water quality criteria for the nation’s second largest estuary, PS, is expanding using the North Carolina ferry-based water quality monitoring project, FerryMon. Three of the North Carolina Department of Transportation ferries will be outfitted with refrigerated ISCO collectors to enable the program to collect photopigment data on weekly to monthly intervals, greatly expanding the spatio-temporal coverage of this system and generating a comprehensive data base for calibration and verification of remote sensing (e.g., AVIRIS, SeaWiFS, hyperspectral) of Chl-α and other diagnostic pigments (Lunetta, et al., in preparation). FerryMon is being developed as a model for a national program of ferry-based water quality assessment, in part based on these indicators for large estuarine and coastal ecosystems serviced by ferries (e.g., Long Island Sound, Delaware Bay, San Francisco Bay, Puget Sound; Paerl, et al., in preparation).
References:
Brasher CW, DePaola A, Jones DD, Bej AK. Detection of microbial pathogens in shellfish with multiplex PCR. Current Microbiology 1998;37(2):101-107.
Iijima Y, Asako NT, Aihara M, Hayashi K. Improvement in the detection rate of diarrhoeagenic bacteria in human stool specimens by a rapid real-time PCR assay. Journal of Medical Microbiology 2004;53(7):617-622.
Motes ML, DePaola A, Cook DW, Veazey JE, et al. Influence of water temperature and salinity on Vibrio vulnificus in Northern Gulf and Atlantic Coast oysters (Crassostrea virginica). Applied and Environmental Microbiology 1998;64(4):1459-1465.
Panicker G, Call DR, Krug MJ, Bej AK. Detection of pathogenic Vibrio spp. in shellfish by using multiplex PCR and DNA microarrays. Applied and Environmental Microbiology 2004a;70(12):7436-7444.
Panicker G, Myers ML, Bej AK. Rapid detection of Vibrio vulnificus in shellfish and Gulf of Mexico water by real-time PCR. Applied and Environmental Microbiology 2004b;70(1):498-507.
Pfeffer C, Oliver JD. A comparison of thiosulphate-citrate-bile salts-sucrose (TCBS) agar and thiosulphate-chloride-iodide (TCI) agar for the isolation of Vibrio species from estuarine environments. Letters in Applied Microbiology 2003;36(3):150-151.
Pfeffer CS, Hite MF, Oliver JD. Ecology of Vibrio vulnificus in estuarine waters of eastern North Carolina. Applied and Environmental Microbiology 2003;69(6):3526-3531.
Randa MA, Polz MF, Lim E. Effects of temperature and salinity on Vibrio vulnificus population dynamics as assessed by quantitative PCR. Applied and Environmental Microbiology 2004;70(9):5469-5476.
Thompson JR, Randa MA, Marcelino LA, Tomita-Mitchell A, et al. Diversity and dynamics of a north Atlantic coastal Vibrio community. Applied and Environmental Microbiology 2004;70(7):4103-4110.
Journal Articles on this Report : 3 Displayed | Download in RIS Format
Other subproject views: | All 135 publications | 32 publications in selected types | All 28 journal articles |
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Other center views: | All 385 publications | 101 publications in selected types | All 90 journal articles |
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Fear J, Gallo T, Hall N, Loftin J, Paerl H. Predicting benthic microalgal oxygen and nutrient flux responses to a nutrient reduction management strategy for the eutrophic Neuse River Estuary, North Carolina, USA. Estuarine, Coastal and Shelf Science 2004;61(3):491-506. |
R828677C001 (2004) |
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Paerl HW, Valdes LM, Joyner AB, Piehler MF. Solving problems resulting from solutions: Evolution of a dual nutrient management strategy for the eutrophying Neuse River Estuary, North Carolina. Environmental Science & Technology 2004;38(11):3068-3073. |
R828677C001 (2003) R828677C001 (2004) |
not available |
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Piehler MF, Twomey LJ, Hall NS, Paerl HW. Impacts of inorganic nutrient enrichment on phytoplankton community structure and function in Pamlico Sound, NC, USA. Estuarine, Coastal and Shelf Science 2004;61(2):197-209. |
R828677C001 (2003) R828677C001 (2004) R830652 (2004) |
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Supplemental Keywords:
phytoplankton, estuarine & coastal indicators, photopigments, nutrients, hydrology, water quality, habitat, ecosystem and regional scale, management, physical factors, climatology, hurricanes, nutrient management, TMDLs, modeling, remote sensing, ferry-based monitoring,, RFA, Scientific Discipline, Air, Ecosystem Protection/Environmental Exposure & Risk, Ecosystem/Assessment/Indicators, Ecosystem Protection, Chemistry, climate change, Air Pollution Effects, Monitoring/Modeling, Ecological Effects - Environmental Exposure & Risk, Environmental Engineering, Atmosphere, Ecological Indicators, atmospheric dispersion models, aquatic ecosystem, climate change effects, ecoindicator, fish habitats, coastal ecosystem, remote sensing, environmental monitoring, environmental measurement, assessment models, nutrient loading, climate, Choptank River, trophic effects, estuarine ecoindicator, estuarine ecosystems, environmental stress, water quality, ecological models, climate model, atmospheric chemistry, photopigment indicatorRelevant Websites:
http:// www.aceinc.org Exit
http:// www.ferrymon.org Exit
http://www.marine.unc.edu/neuse/modmon Exit
http://www.chesapeakebay.net Exit
Progress and Final Reports:
Original AbstractMain Center Abstract and Reports:
R828677 Organotypic Culture Models For Predictive Toxicology Center Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R828677C001 Phytoplankton Community Structure as an Indicator of Coastal Ecosystem
Health
R828677C002 Trophic Indicators of Ecosystem Health in Chesapeake Bay
R828677C003 Coastal Wetland Indicators
R828677C004 Environmental Indicators in the Estuarine Environment: Seagrass Photosynthetic Efficiency as an Indicator of Coastal Ecosystem Health
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.
Project Research Results
28 journal articles for this subproject
Main Center: R828677
385 publications for this center
90 journal articles for this center