OS25M-01
The Impact of Different Classes of PCBs on Marine Mammal and Human Health: a new Assessment of Immunotoxicity
The oceans and their resources have become increasingly well recognized as sources of food for humans and for the biodiversity they harbor. Nevertheless, environmental contaminants such as PCBs, which are now ubiquitous in all oceans and found in tissues of animals and humans dependent on marine resources, have been the source of increasing concern for their potential effects on health of animals and humans. PCBs consist of mixtures of 209 different congeners, each with distinct physical, chemical and biological characteristics. The toxicity of PCBs has been studied (mostly in lab animals) on the basis of either commercial mixtures or individual congeners, with emphasis on the coplanar congeners, which have documented dioxin-like activity. The current TEQ approach to document the toxicity of mixtures of organochlorines assigns a dioxin-related toxicity equivalent factor (TEF) to each congener, and assumes that the total toxicity of the mixture is equal to the sum of the toxicity of the components of the mixture (TEQ= TEF x concentration for each congener). While practical, this approach ignores the possible dioxin-independent toxicity of the most abundant non-coplanar PCB congeners, which are assigned a TEF of 0. We performed in vitro dose-response experiments to quantify the direct immunotoxicity of different PCB congeners in humans, mice and different species of marine mammals, to quantify the importance of inter-species differences and determine if the conformation of PCB congeners can be used to predict their immunotoxic potential. The immune functions investigated included neutrophil and monocyte phagocytosis, as well as LPS and Con A-induced B and T lymphocyte proliferation, respectively. Results to date demonstrate some general similarity between the effects of PCBs that belong to the same category (non-ortho (NO), mono-ortho (MO) and Di-ortno (DO)-substituted congeners). For example, NO PCBs generally reduced phagocytosis in most species, while NO did not. While human monocyte phagocytosis was reduced by most congeners, the concentration that reduced or increased the function by fifty percent (EC50) was greater than 20 ppm for NO, greater than 18 ppm for DO, and lower than 18 ppm for MO congeners. Nevertheless, there were obvious exceptions to this general rule, with differences between congeners and species. For example, PCB 153 did not result in reduced phagocytosis in all species tested while PCB 138 and 180 did. Also, MO PCBs generally increase lymphocyte proliferation in mice, but reduced it in humans and marine mammals. Overall, our results highlight the differences between species, question the use of the conventional mouse model to predict toxicity in other species, and offers initial support to the hypothesis that the structure of PCBs may help predict their immunotoxicity, which is not solely associated with dioxin-like mechanisms (as the NO congeners, which have demonstrated toxicity, have little or no affinity for the aryl hydrocarbon (Ah) receptor, through which dioxin and dioxin-like effects are mediated). Completion of this study will allow a more definitive and accurate interpretation of our results. Overall, a better characterization of the immunotoxic effects of PCBs in different species will improve our ability to perform more focused, precise and relevant risk assessment for environmental and human health, and help determine the possible impacts of the global pollution of our oceans on several species (such as marine mammal and humans) depending on the complex marine food chain.
OS25M-02
Evaluating the Potential Health Impacts of Polybrominated Diphenyl Ethers (PBDEs): Developmental Toxicity Using a Larval Fish Model
Polybrominated diphenyl ethers (PBDEs) are a class of brominated hydrocarbons that are used as a flame retardant additive in plastics, polyurethane foam, and textiles. While PBDEs have helped reduce the loss of human life from fires, concerns arose recently about the health risks of PBDEs as these chemicals have become pervasive in the environment. PBDEs are now common contaminants in marine and freshwater habitats, and high concentrations of PBDEs have been detected in tissues from fish, marine birds, and marine mammals. Levels of PBDEs are also rising rapidly in human tissues from North America, elevating concerns about potential health impacts of these chemicals. In an effort to evaluate possible health effects of PBDE exposure for both humans and wild fish populations, we have begun to explore mechanisms of PBDE toxicity using the zebrafish ({\it Danio rerio}) model system. Zebrafish were spawned in captivity, and offspring were exposed continuously to the PBDE congener 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) beginning at 3-5 hrs post-fertilization (hpf). Larvae treated with BDE-47 at doses of 0.016 $\mu$g BDE-47 per fish (77.5 $\mu$g BDE-47 per g body mass) and greater showed a delay in hatching from the chorion and were smaller in body size by 72 hpf. These BDE-47 treated larvae developed a dorsally-curved tail that was first detectable at 72 hpf and became progressively pronounced over the next several days. Further examination showed that BDE-47 induced an elevation in heart rate at 96 hpf, which subsequently developed into a cardiac arrhythmia by 144 hpf. This arrhythmia may have contributed to the elevated mortality seen in larvae exposed to high levels of BDE-47. Overall, this work indicates that fish exposed to BDE-47 during early life can show developmental abnormalities that have detrimental effects on survival. Whether more subtle toxic effects occur with long-term exposure to lower levels of PBDEs remains to be tested.
OS25M-03
Antibiotic Resistance in Aquatic Environments: What Metals got to do With it?
Due to genetic linkages between microbial resistances to metals and antibiotics, we hypothesized that environments contaminated with toxic metals are enriched in antibiotic-resistant bacteria. The effect of toxic metal exposure on mixed communities was examined using laboratory microcosms and field surveys of metal-contaminated coastal and freshwater ecosystems. We found that experimental community exposure to Hg, Cd, and Ni increased the fraction of bacteria resistant to multiple metals and antibiotics. Likewise, elevated frequencies of antibiotic resistance were found in metal-contaminated field study sites, using culture-based and culture-independent methodologies. The abundance of integrons and resistance-encoding plasmids was examined in microbial isolates and environmental DNA extracts. Globally, vast areas have metal concentrations similar to those used in our studies. Thus, industrial metal emissions may contribute to the maintenance and spread of antibiotic resistance genes among environmental bacteria, including opportunistic human pathogens. In addition, metal-induced selection may interfere with water contamination source tracking based on antibiotic resistance patterns.
http://isarco.srel.edu/
OS25M-04
Recreational Beach Visitor Perceptions of Health Risk and Impact of Water-Borne Pathogens in Orange County, CA
Attitudes and behavior of recreational visitors to the Orange County, CA Huntington State and City public beaches were surveyed on the topics of health and recreation as relating to ocean water at the beach. The primary analysis determined relationships between stated attitudes and behavior involving choices about beach-related health and recreation. The two main aspects of this analysis were an assessment of the economic utility of beach-based recreation and health in comparison to non-beach values, and the population cross-section of attitudes toward bacterial pollution in recreational coastal waters. The relative revealed risk-aversity of beach visitors for different activities is of particular interest as a potential measure of public response to information campaigns and management policies intended to protect public health in an efficient manner. The initial phase of this study consisted of a series of interviewer-administered surveys collected over a continuous three-week period during August 2005 from a randomized sample of daytime visitors to Huntington State and City beaches. Both closed-ended survey ($N = \sim 1000$) and open interview formats ($N = \sim 150$) were used in addition to video monitoring of attendance patterns, such as visitors per day, arrival and departure patterns, and activity preferences at different locations. These data are planned for integration into a Monte Carlo economic model of beach management strategies aimed at maximizing public health benefits and recreational utility. The data have contributed to an interpretive analysis of behavioral trends and their attitudinal correlates among recreation seekers at the Huntington Beach location for comparison with other locations.
OS25M-05
Presence and Infectivity of Human Pathogenic Viruses in a Heavily Urbanized Estuary
Many human viral diseases can be linked to environmental sources, including exposure to pathogens through seafood consumption and recreational coastal waters. Water quality monitoring programs seldom measure pathogens directly and viral "survival" in turbid coastal waters is poorly known. Therefore, we recently began determining the presence and infectivity of human viruses in Long Island Sound along a contamination from New York City to the Atlantic Ocean. During Spring and Fall 2005 cruises, we concentrated viral fractions from sieved (<0.2 $\mu$m) 100-L samples by ultrafiltration at 7-8 stations along the transect. Commonly employed sewage proxies (fecal coliforms, enterococci, {\it Clostridium perfrigens} spores and coliphage) as well as total viral and bacterial abundances (fluorescence microscopy), bacterial production and oceanographic conditions were all measured at each station. Steep spatial gradients in microbiological contamination were evident in all routine sewage proxies during our two cruises, attenuating to detection limits within the city boundaries. Coliforms, enterococci, {\it C. perfringens} spores and coliphage were 30 to 4000 times more abundant in urban receiving waters than at central and eastern Long Island Sound stations. Our group is experimentally evaluating oceanographic processes that contribute to attenuation of proxy signals and loss of infectivity of free virions. To examine relationships between detectable genomes and infective titers of human virions in our samples, quantitative PCR and infectivity bioassays were conducted on shared samples. Viral DNA/RNA was amplified from samples by Q-PCR and QRT-PCR using primers employed by SBU virologists for selected enteroviruses, adenoviruses and rotaviruses. Estimates of environmental genome abundances were derived from CT (threshold cycle) and standard curves from cultured viruses. Selected amplicons will be purified and sequenced. Nucleotide sequences will then be challenged by BLAST analysis against known sequences found in GenBank to confirm identity. To determine the infective titer of human virions, environmental concentrates were bioassayed against several mammalian cell lines. Bioassays included plaque formation in HeLa and monkey kidney cell lines and the much more sensitive immunoassay using appropriate polyclonal or monoclonal antibodies for early detection of viral replication within mammalian cells. Unique plaques will be propagated and identified by PCR and sequencing. Our preliminary results from plaque assays suggest that infective rotaviruses and polioviruses were present at our most contaminated sites. Details of methods development and findings will be presented. The quantitative importance of waterborne human viruses and infective lifetime in this coastal environment will be discussed in the context of risk assessment.
OS25M-06
Amoebae and {\it Legionella} Species in Mt Hope Bay
Amoebae are known to serve as environmental reservoirs for species of {\it Legionella}. Most of these reports come from freshwater environments, but we have recently documented the occurrence and repeated recovery of amoeba cultures positive for legionellae from the coastal marine environment of Mt Hope Bay. Sediment and water from four sites in this New England estuarine system were examined over a full year. The sites included the thermal plume region of a power plant, a secondary sewage outfall, a brackish environment and a coastal marine region considered impacted by normal bay conditions. Nucleic acids were extracted directly from water and sediment samples. Sediments were also enriched for amoeba cultures by agar plate methods, and amoeba isolates were processed for nucleic acids. All samples were amplified by a nested PCR procedure specific for {\it Legionella} species. Positive amplifications were recovered from sediment samples and amoeba cultures, and these products were collected for sequence analysis to determine what species of the bacterium were present. Although most of the legionellae were more similar to undescribed environmental isolates, at least one was similar to {\it L. anisa}, a human pathogen. Amoeba cultures positive for legionellae were also amplified using 18S ribosomal gene primers and are currently being sequenced to determine whether there is a relationship between the type of amoebae present and the type of {\it Legionella} present. There is potentially a seasonal pattern to the occurrence of legionellae and amoebae in Mt Hope Bay, and this will be discussed with reference to basic water column measurements taken during sample collection. These results do suggest the prevalence of potentially pathogenic legionellae in saline environments may be higher than previously thought, and could represent potential human health issues.
OS25M-07
Impact of Climate and Weather on {\it Salmonella} Densities in the Aquatic Environment
The highest salmonellosis case rates in the country have been consistently observed in several counties in southern Georgia, USA (>80/100,000 in 2004). While the disease is often considered to be foodborne, rarely have food sources been confirmed in these rural areas of Georgia. Retrospective analyses of case-rates in this region have demonstrated an association between rainfall, season and monthly case-rates, suggesting that environmental sources and climatic drivers of {\it Salmonella} may be important in disease transmission. In this study we evaluated surface waters in two high case rate counties as possible reservoirs of non-animal product-associated {\it Salmonella} and of the role of climate and weather in the loading and persistence of {\it Salmonella} in the aquatic environment. Water samples were collected monthly from 6 stations beginning in March 2005 from the Little River Watershed and {\it Salmonella} spp. densities were estimated using a 3-step Most Probable Number (MPN) assay. {\it Salmonella} densities at these stations ranged between Not Detected during spring months and 7 MPN/100 ml in summer months. Significant climatic influences on measured {\it Salmonella} densities included a direct correlation with water temperature (r=0.49 p<0.05) and precipitation levels in the 48 hours prior to sampling (r=0.68 p<0.05). A 62% increase in {\it Salmonella} densities was observed from spring to summer months which coincided with both higher temperatures and the rainy season. This was followed by a 45% decrease in {\it Salmonella} densities from summer to fall months coinciding with decreasing temperatures and fewer rainfall events. This trend in environmental prevalence of {\it Salmonella} is consistent with trends observed in clinical cases and supports the notion that climatic variability coupled with environmental exposures play a role in disease transmission in this watershed.
OS25M-08
{\it Staphylococcus Aureus} Isolates From Recreational Beach Waters and Human Clinical Samples Have a Similar Broad Genetic Diversity
In Hawaii, as elsewhere, infections by {\it Staphylococcus aureus} (Sa) that are resistant to antibiotics are a growing public health problem. {\it Staph. aureus} (Sa) can consistently be recovered from bathing beaches in Hawaii, suggesting that community-acquired Sa infections may be transmitted via recreational waters. Sequence analysis of the protein A gene ({\it spa}) was used to determine whether strains of Sa commonly associated with disease are found in recreational waters. Sa strains isolated from coastal seawater around Oahu were compared to clinical isolates obtained from in- and out-patients. Sequence analysis of the VNTR region of {\it spa} (spa-typing) has a high index of diversity (0.969 (0.958 - 0.980) using our data), and can be used to track outbreaks as it indexes microevolution. Each spa-type can be considered to represent an individual clonal expansion. Spa-typing was performed on 126 seawater and 53 clinical isolates submitted to the Pacific Microbial Pathogen Collection. Methicillin-resistant Sa (MRSA) were found among environmental (13%) and clinical (19%) isolates. Of the 71 spa-types identified, 32 were previously unreported to the international Ridom SpaServer database. Phylogenetic analysis of the spa-type sequences was performed using BURP, a clustering algorithm for sequence alignment of tandem repeats with excision, duplication, substitution and indels (M. Sammeth, T. Weniger, D. Harmsen, and J. Stoye, WABI 2005, LNBI 3692, pp. 276-290, 2005.). Both clinic- and ocean-derived clone-types were seen to be equally distributed throughout the phylogenetic span. Spa-types with MRSA phenotypes were also distributed throughout the tree. Furthermore, 12 spa-types were observed in both seawater and clinical isolates, including a previously un-reported MRSA strain with an assigned spa-type of tx517. Because spa-typing differentiates clone-types, these isolates extracted from different milieu have a common source. Our results suggest strains of Sa recovered from Hawaiian beach waters have a highly diverse ancestry that is common to the diverse clinical isolates. Since Sa appears to be shed into coastal seawater by bathers, the broad diversity of Sa likely reflects the diverse geographical origins of visitors to the beaches of Hawaii. The extent to which these strains pose a risk to bathers or a potential for enhancing antimicrobial resistance through their contact with other seawater organisms is uncertain and merits further investigation.
OS25M-09
Diverse Population of Swimmers in Hawaii's Beaches Release Diverse Strains of {\it Staphylococcus aureus} into Coastal Waters
We previously reported that methicillin-sensitive (MSSA) and methicillin-resistant (MRSA) {\it Staphylococcus aureus} were readily recovered from swimming beaches in Hawaii. These results are significant because in Hawaii, there is an association between swimming at marine beaches and {\it S. aureus} skin infections. Moreover, MRSA has become a serious public health problem, and the infection rate of community associated {\it S. aureus} (CA-MRSA) has increased relative to hospital associated (HA-MRSA), especially among Pacific Islanders. {\it S. aureus} was more readily isolated from popular beaches, which are used by residents and transient tourists. The contaminating source of {\it S. aureus} in beach water is believed to be the diverse population of swimmers. If this is true, the strains of {\it S. aureus} recovered from beach water should represent diverse strains. The objective of this study was to characterize the strains of MSSA and MRSA isolates recovered from beach water samples based on their antibiotic susceptibility patterns to eight antibiotics (penicillin, gentamicin, cefotoxime, tetracycline, vancomycin, erythromycin, ciprofloxacin, ampicillin) and ribotyping when analyzed by the Riboprinterr. The results showed 6 different antibiotic susceptibility patterns among the 25 MSSA isolates and 13 different antibiotic patterns among the 17 MRSA isolates. The diversity in the strains of MRSA was further supported by use of the E-Test, which showed that the MIC of oxacillin for 15 MRSA isolates ranged from 4 to >256 micrograms/ml. The genetic diversity of the MSSA and MRSA strains isolated from beach water samples was shown by the Riboprinterr analysis, which characterized 20 MSSA isolates into 8 distinct ribogroups and characterized 16 MRSA isolates into 12 distinct ribogroups. In conclusion three lines of evidence (antibiotic susceptibility patterns, MIC of oxacillin, ribotyping) provide evidence that {\it S. aureus} (MSSA, MRSA) isolates from beach water samples were of diverse strains. These results support the hypothesis that many different swimmers shed {\it S. aureus} into beach water.
OS25M-10
Study of Staphylococcus aureus Colonization and Exposure to Recreational Seawater
Background: Staphylococcus aureus (Sa) has become a growing problem with antimicrobial resistance and the spread of virulent strains in the community. The recovery of Sa and methicillin-resistant Sa (MRSA) strains from the bathing beaches of Hawaii emphasizes the need to explore the possible role of recreational seawater exposure of people to Sa strains that may lead to colonization and hence infection with this organism. Methods: One hundred college students gave their consent to have a culture taken from their anterior nares and to respond to a survey of their activities over the prior two weeks. Cultures were planted on broth, which included CHROMagar to more easily identify Sa. Five colonies were subcultured from each plate which suggested Sa growth. Results: Of the 100 students, 33 were culture positive for Sa. Three of the strains were resistant to oxacillin. None of the participants had any signs or symptoms of an infection in their nose or on their face. The survey indicated 14 of 33 (42%) colonized with Sa had seawater exposure (wading, swimming, surfing, paddling, or diving) compared with 28 of 67 (42%) who did not. Of those with seawater exposure 12 of 37 (32%) were colonized with Sa compared with 21 of 63 (33%) who were not. There was no apparent association with any of the specific water sports and colonization. No statistically significant association could be found between colonization and gender (30 vs. 28%) or ethnicity (6 vs. 16% Hawaiian). There were no significant associations with prior Sa infections (3 vs. 5%) or antibiotic therapy during the last 3 months (15 vs. 22%) nor household members with infection (none for either group) nor with pets (45 vs. 49%). The low number of students (3) colonized with MRSA was not enough to note any significant correlations. Conclusion: No association with seawater exposure and colonization with Sa could be demonstrated by this simple methodology and a relatively small population studied. Additional testing of a larger group of people and strain typing may be helpful in determining whether Sa in the environment of Hawaii is a clinical problem or not.
OS25M-11
Dynamics of Aquatic Fecal Contamination, Fecal Source Identification, and Correlation of Bacteroidales Host-Specific Marker Detection with Fecal Pathogens
Fecal pollution impairs the health and productivity of coastal waters and causes human disease. PCR of host-specific 16S rDNA sequences from anaerobic Bacteroidales bacteria offers a promising method of tracking fecal contamination and identifying its source(s). Before Bacteroidales host-specific markers can be used to assess human health risks it is important to know how detection of the markers correlates with the presence of human pathogens and how long the marker organisms survive relative to pathogens, standard indicators, and environmental changes. We correlated Bacteroidales molecular markers with standard fecal indicator bacteria and environmental conditions in samples collected over a two-year period from Tillamook Bay and five tributaries within the Tillamook River Basin. We performed Bacteroidales PCR assays using host-specific primers for fecal source identification, and recorded E. coli MPN, temperature, turbidity, and 5-day precipitation. In samples near point sources of fecal contamination we found close correlation between E. coli MPN and detection of Bacteroidales markers. Climate and water quality data suggested a rainfall-runoff model for microbial source loading, mirroring the annual precipitation cycle, and compared to humans, ruminants were a more significant source of fecal input. Two anomalies arose from this dataset. In rivers, E. coli counts increased over summer months, while the probability of detecting Bacteroidales markers fell to a minimum from April to July, increasing in the fall. In the bay, Bacteroidales markers were detected at high levels, but this was not reflected in E. coli MPN. In a separate 3 year study, we tested 437 water samples for Bacteroidales host-specific molecular markers, and for presence of E. coli O157:H7, Salmonella spp., and Campylobacter. The odds of detecting E. coli O157:H7 and Salmonella spp. were significantly higher when ruminant-specific markers were present. Detection of the human-specific markers did not correlate with the presence of E. coli O157:H7 or Salmonella; however, the odds of Campylobacter being present were 4 times greater when human-specific markers were detected. These two studies demonstrate that Bacteroidales host-specific markers are detected when human pathogens are present, and support their application in assessing human health risk.
OS25M-12
A Microbial Diversity Survey of a Sewage- and Thermally-Impacted Estuary: Mt. Hope Bay, Massachusetts
Coastal marine environments have been impacted by human activity for several centuries, including shoreline alteration, nutrient introduction, sedimentation, toxic compound release, and thermal modification. Mount Hope Bay, Massachusetts is an ideal site to base a study of human pathogen presence and distribution because it has several important sources of human impact, including sewage disposal sites and the thermal outfall of a power plant within a mile of each other. The Bay is currently undergoing limited monitoring for several different parameters, including fish populations, river runoff, meteorological forcing, tidal cycles and water chemistry as part of the Mt. Hope Bay Natural Laboratory (MHBNL) program, a 5-year interdisciplinary project at the University of Massachusetts Dartmouth School of Marine Science and Technology (SMAST). While phytoplankton and zooplankton communities in the water column have been fairly well monitored, although not at a molecular level, microbial communities remain relatively uncharacterized. We report the first comprehensive (eukaryal, bacterial, archaeal) data from small-subunit ribosomal RNA gene clone libraries for samples collected near the thermal plume and underlying sediments of the Brayton Point Power Plant. We have partial sequences of nearly 4,000 clones from 2 different sites and have further sequenced 1,000 unique clones from these to full-length. Not surprising, our findings reveal a highly diverse consortium of the three domains including relatives of sludge bacteria, polyaromatic hydrocarbon-degrading bacteria, and representatives related to the genera {\it Staphylococcus}, {\it Streptococcus}, and {\it Clostridium}. Phylogenetic analyses will further unveil the relationships of many of these clones and determine whether they are related to known pathogens and may possibly represent undescribed taxa. It is clear that even limited knowledge about the overall microbial community composition can lead to important observations about the ecosystem as a whole. Furthermore, understanding whether free-living pathogens participate in relationships with other members of the microbial community will be important in understanding their distributions and persistence.
http://www.whoi.edu/science/cohh/whcohh/
OS25M-13
Assessing the Role of Particle Attachment in Fate and Transport of Microbial Indicators and Pathogens in an Eutrophic Estuary
In order to understand the potential public health risk associated with microbial contaminants contributed to estuarine environments via point sources (e.g. sewage treatment plants) and non point sources (e.g. stormwater runoff), it is necessary to understand fate and transport. We are utilizing a multidisciplinary approach to generate information on the presence and transport of both free (unbound) and particle associated microbial indicators, Enterococcus (ENT) and E. coli (EC), pathogens (Vibrio sp.) and microbial markers (e.g. Bacteroides) in the Neuse River Estuary. For sample collection, we are using a range of Eulerian (fixed locations) and Lagrangian (drifter deployments) sampling approaches, combined with analytic approaches involving particle analysis, traditional culture-based microbial analyses, and newly developed Quantitative PCR analyses. In order to assess the impacts of stormwater runoff, we are also conducting a range of temporal scale sampling, including storm response within 24 h and the deployment of a floating platform for autonomous, in situ water sampling and oceanographic data collection. Increases in concentrations of ENT and EC coincide with increases in particles in suspension during and following storm events. In surface waters, both ENT and EC exhibit similar patterns, controlled primarily by runoff inputs (i.e., storms). In bottom waters, resuspension of sediments due to wind mixing appears to be a source of particles and both indicator bacteria and Vibrio sp. Partitioning, which did not change significantly following inputs, exhibited an overall average of 38% of indicator bacteria associated with particles capable of settling out of the water column. The goal of this research project is to provide data to populate existing estuarine models of fate and transport for successful predictions of microbial transport to better protect public health.
OS25M-14
Use of Remotely Sensed Parameters to Predict Levels of {\it Vibrio parahaemolyticus} in Gulf Coast Water and Underlying Oysters ({\it Crassostrea virginica})
{\it Vibrio parahaemolyticus} ({\it Vp}) is a halophilic gram-negative bacterium and a major cause of food-related diarrhea in the United States and especially in nations that consume large amounts of seafood. {\it Vp} occurs naturally in saltwater, but specifically accumulates in oysters through filter-feeding; indeed, {\it Vp}-associated diarrhea is frequently associated with the consumption of raw oysters. Total {\it Vp} levels in oysters increase as water temperatures increase; therefore, in light of global warming and thus increased summer temperatures in Gulf of Mexico waters, it has become increasingly important to efficiently monitor {\it Vp} levels in market oysters. Current FDA-approved monitoring methods involve molecular tools which measure {\it Vp} levels in situ (IS) in harvested oysters, but a more efficient monitoring method which can quickly relay information to oyster harvesters and consumers may decrease the incidence of {\it Vp} -associated illness. This may be accomplished by incorporating readily available remotely sensed (RS) satellite data on sea surface temperature (SST) into the current FDA risk assessment model. Additional parameters such as turbidity, salinity, and chlorophyll levels could further improve the risk assessment. When we compared IS data to RS data on water temperature, turbidity, and chlorophyll, these data were significantly correlative. Analysis of historical IS and RS SST data indicated that when imported into a revised FDA Risk Assessment model, the differences between predicted {\it Vp} densities based on RS SST or on IS SST were less than 5%, further supporting the use of RS SST in place of IS SST data. Furthermore, in MS, turbidity and chlorophyll levels correlated with both total and pathogenic {\it Vp} densities when examined independently of temperature and salinity effects. These parameters may be used in the future to improve the efficiency of the current FDA Risk Assessment model and may possibly be used to predict {\it Vp} levels in areas for which IS processing of oysters may be otherwise impractical.
OS25M-15
Physical Predictors of Biological Water Quality: Linking Ocean Temperature and Human Health Risk
Ocean temperature may be an important predictor of human health risk through a variety of mechanisms. Cold water may indicate movement of polluted subthermocline waters onshore or could serve to increase inactivation times for pathogens introduced from terrestrial sources. In addition, nutrient-rich cold water may fuel phytoplankton blooms which provide surfaces for pathogens to adhere to, or may be toxic themselves. Here, we present high-resolution temperature data from a near shore instrument array deployed off Huntington Beach, California with measurements at the 10m, 15m, and 20m isobaths coupled to surfzone measurements of chlorophyll, nutrients, and fecal indicator bacteria. Temperature records show evidence of both short-term variability, possibly associated with internal waves, and longer term variability indicative of coastal upwelling. We use both regression and spectral analyses to show that water quality varies directly with certain biological parameters, yet lags physical variables by timescales that vary by station.
OS25M-16
Comparing and linking plumes across modeling approaches
River plumes carry many pollutants, including microorganisms, into lakes and the coastal ocean. The physical scales of many stream and river plumes often lie between the scales for mixing zone plume models, such as the EPA Visual Plumes model, and larger-sized grid scales for regional circulation models, such as the Princeton Ocean Model (POM) used to simulate Great Lakes circulation. A potential advantage of the smaller scale models is that they frequently use entrainment theory to simulate the growth of plumes, a technique that has proven useful in simulating turbulent plumes discharged from various channels and structures, some approaching the dimensions of rivers. This study explores the overlap and potential for linkage of some of these models. A comparison of predictions is also presented. Applications for both the Great Lakes (Burns Ditch, near Porter, Indiana) and the coastal ocean are included.
OS25M-17
Measuring the Interaction Between the Healths of Coral Reef Ecosystems and Coastal Communities
Coral reefs are the world's most celebrated indicators of ocean health. While the global trajectory of coral reef health is now well documented, and the accompanying loss of economic benefits increasingly demonstrated, the consequences in terms of human health have been largely ignored. Reefs provide a wide array of benefits to humans, contributing most directly to the health of subsistence fishing communities located on adjacent coasts and islands. Interactions between human and marine ecosystem health are complex, bidirectional and nonlinear. Quantitative data on human health outcomes are rarely available in formats or contexts that allow unequivocal linkages to ocean health. We draw on a broad range of data and experience to identify key links in the ecological chain from the coral polyp to the human society. Our conclusions are that humans are components of coral reef ecosystems, few studies of reef health incorporate human health, few data are available to quantify the health services reefs provide to people, and human health security is essential to the preservation of coral reef ecosystems. We present a research design to test these hypotheses.
OS25M-18
Improving Harmful Algae Monitoring to Reduce Health Risks and Economic Impacts in Washington State
Amnesic Shellfish Poisoning caused by the neurotoxin domoic acid (DA) was first documented in eastern Canada in 1987. The diatom Pseudo-nitzschia sp. produces the toxin, and is found in coastal and inland Washington waters, where it is concentrated by filter feeding shellfish. Since 1991 the presence of DA in shellfish tissue has been monitored in Washington, and twice in the last three years outbreaks have occurred in Puget Sound, which were detected above the action level of 20ugDA/g tissue. The most recent and highest level occurred in October 2005. A value of information approach was used to evaluate uncertainties about conditions leading to shellfish DA contamination based on the published literature. Monitoring programs were reviewed based on their effectiveness to prevent DA from entering the food supply, protect living resources and minimize economic impacts to fishermen, aquaculturists and the tourism industry. Robust monitoring programs can reduce the mistrust or disregard of public health messages due to lack of understanding of the underlying risk associated with shellfish consumption and assist consumers to better interpret seafood advisories. Criteria were identified to design effective sampling protocol to detect the presence of Pseudo-nitzschia cells or DA before toxic conditions arise, (providing an early warning system). A functioning monitoring program requires that sampling be conducted frequently with a wide geographic coverage so that important events are not missed and shellfish harvest can be closed to protect human health.
OS25M-19
Characterization of Intrapopulation Genetic Variability of the Toxic Dinoflagellate Alexandrium fundyense Throughout the Course of a Bloom
Coastal waters of the northeastern U.S. are subject to recurrent outbreaks of paralytic shellfish poisoning (PSP) caused by the toxic dinoflagellate Alexandrium fundyense. PSP toxicity shows considerable spatial and temporal variability, due in part to growth and accumulation zones defined by coastal circulation patterns. Another likely contributing factor is phenotypic heterogeneity in the A. fundyense population, evidenced by dramatic differences in inherent toxicity amongst clonal A. fundyense isolates from the region. Overall, this variability in PSP toxicity represents a significant challenge from public health and fisheries management perspectives. As part of the Woods Hole Center for Oceans and Human Health, we aim to investigate the manner in which genetic, environmental and hydrographic factors regulate PSP toxicity. More effective management of shellfish resources threatened by PSP toxins requires an understanding of the population biology of Alexandrium species, as well as the manner in which these different genotypes respond to environmental conditions, ultimately affecting the quantity and types of toxins accumulating in shellfish. From May to July of 2005, the Gulf of Maine region was affected by the largest toxic Alexandrium bloom in decades. During this event, several hundred clonal isolates of A. fundyense were established from a variety of water samples taken throughout the bloom, in different geographic locations, and at different depths. The genotypes of these toxic bloom isolates are currently being determined using microsatellite markers. These markers have been shown to be highly polymorphic in A. fundyense, and are able to resolve fine-scale genetic differences between isolates. General features of the Gulf of Maine Alexandrium bloom population will be presented, as will analyses of the relationships between individual genotypes and the comparison of population changes through time and space.
OS25M-20
Exploration of Deeply Buried Arctic Sediments for Microbial Diversity and Novel Biomedical Resources
Microorganisms inhabiting deeply buried marine sediments constitute a significant portion of the Earth's biomass. It is presumed that this large biomass harbors immense genetic diversity. This diversity is of great interest from an evolutionary viewpoint but has also drawn attention as a potential new frontier for biomedical discovery. Our current understanding of microbes inhabiting deeply buried marine sediments is largely based on samples collected from continental shelves in tropical and temperate latitudes. The geographical range of marine subsurface coring was recently expanded during the Integrated Ocean Drilling Program Arctic Coring Expedition (IODP ACEX). This expedition successfully cored the 428 m sediment stack on the Lomonosov Ridge in the central Arctic Ocean during August and September 2004. The drill sites were located 250 km from the North Pole under ~1300 m of water. The recovered cores varied from siliciclastic sediment low in organic carbon (< 0.2 %) to organic rich black sediments that rapidly accumulated in the early middle Eocene. Three geochemical environments were characterized based on porewater chemical analysis: an upper ammonium oxidation zone, a carbonate dissolution zone and a deep (> 200 meters below sea floor) sulfate reduction zone. The biodiversity of microbes within each zone was assessed using phylogenetic markers, including16S rRNA. The biosynthetic potential of organisms from these habitats was examined in environmental DNA extracts using primers targeting genes involved in secondary metabolism, for example, polyketide synthases and nonribosomal peptide synthetases. The data derived from the molecular analyses will be analyzed in the context of the sediment lithology and porewater geochemistry in order to make predictions on the occurrence of these microorganisms and guide sampling efforts for future explorations of the marine subsurface.
OS25M-21
Use of Biodegradable Microparticles Containing Rhamnolipid Biosurfactant to Emulsify oil in Recreational Boat Marinas in Tampa Bay.
In an effort to expand the technology of bioremediation of residual petroleum hydrocarbons in marine environments, microencapsulation technology was investigated as a method of biosurfactant delivery to contaminated sites. Microparticles are composed of active or inactive materials encapsulated in a polymer coating designed for controlled release of the encapsulated substance. In this study the encapsulated substance is rhamnolipid biosurfactant produced by Pseudomonas aeruginosa. These biosufactants have been found to successfully emulsify petroleum hydrocarbons and increase microbial action on compounds that are atypically bioavailable. Petroleum hydrocarbon concentration and microbial population density in the surface waters of three heavily population recreational boat marinas in Tampa Bay, Fl were monitored from June 2005 to September 2005. Results showed concentrations ranging from 3.9 to 179.82 μg l-1. Accidental spillage of fuel and engine oil from recreational boats is likely the major contributor of these elevated oil levels. The solubility of the petroleum hydrocarbons in the Tampa Bay samples was determined by emulsification assay, which showed that solubility increased by 85% in the presence of biosurfactants.
OS25M-22
Effects of contaminated sediment on the early life stages of winter flounder, Psuedopleuronectes americanus
Winter flounder, Pseudopleuronectes americanus, is unique among commercial flatfishes from marine waters of the Northeast USA because it spawns in estuaries and produces adhesive, negatively buoyant eggs. This creates the potential for embryonic exposure to toxic sediments, which can result in lethal and sublethal effects. These effects threaten the sustainability of this popular fishery. Our work in Yr 1 of this project showed that winter flounder had higher in situ mortality, and displayed a variety of lethal (mortality in various early-life stages)and sublethal (morphological, behavioral) effects following an embryonic exposure to sediments of Raritan Bay, New Jersey. Additional laboratory methods will be used in Yr 2 of this project in order to assess histological and biochemical responses of early life-stage flounder to these sediments. Juvenile fish from Yr 1 experiments will be assessed for gender, and vitellogenin production.
OS25M-23
Methylmercury Production and Mobilization on the Continental Shelf as a Source of Mercury in Marine Fish
Exposure of humans to monomethylmercury (MMHg) occurs primarily through consumption of marine fish, yet there is limited understanding concerning the biogeochemistry of MMHg in the biologically productive coastal ocean. We examined the cycling of MMHg in sediments at three locations on the continental shelf of southern New England in September 2003. MMHg in surface sediments is related positively to inorganic Hg (Hg(II) = total Hg - MMHg), the geographical distribution of which is influenced by organic material. Organic matter also largely controls the sediment-water partitioning of Hg species and governs the availability of dissolved Hg(II) for methylation. Potential gross rates of MMHg production, assayed by experimental addition of $^{200}$Hg to intact sediment cores, are correlated inversely with the distribution coefficient ({\it K}$_{D}$) of Hg(II) and positively with the concentration of Hg(II), most probably as HgS$^{0}$, in 0.2-$\mu$m filtered pore water of these low-sulfide deposits. Moreover, the efflux of dissolved MMHg to overlying water (i.e., net production at steady state) is correlated with the gross potential rate of MMHg production in surface sediments. These results suggest that the production and efflux of MMHg from coastal marine sediments is limited by Hg(II), loadings of which presumably are principally from atmospheric deposition to this region of the continental shelf. The estimated diffusive flux of MMHg from the shelf sediments averages 9 pmol m$^{-2}$ d$^{-1}$. This flux is comparable to that required to sustain the current rate of MMHg accumulation by marine fish, and may be enhanced by the efflux of MMHg from near-shore deposits contaminated more substantially with anthropogenic Hg. Hence, production and subsequent mobilization of MMHg from sediments in the coastal zone may be a major source of MMHg to the ocean and marine biota, including fishes consumed by humans.
OS25M-24
Comparative sensitivity of Pacific Herring, Sea Urchin and Top Smelt bioassays to creosote
Forage fish are an important link in trophic food chains of aquatic ecosystems. Pacific herring, Clupea pallasi has suffered major population declines in several locations throughout Puget Sound, possibly as the result of pollutant stresses. Personnel at Shannon Point Marine Center have developed herring embryo and larval bioassay protocols for possible use as WET tests. The goal of this research was to compare the sensitivity of herring bioassays to two EPA approved tests protocols: Top smelt (Antherinops affinis) larval survival and growth test, and the green sea urchin (Strongylocentrotus droebachiensis) embryo development test, using creosote solutions as the reference toxicant. Creosote compounds are commonly found in marine waters of Puget Sound as wood preservatives, but there is limited knowledge about the effects that these compounds on aquatic organisms, especially their larval stage. I performed five different bioassays using varying concentrations of a creosote solution (treated as an effluent), and hypothesized that herring embryos and larvae were as sensitive to creosote and its related compounds as sea urchin embryos and top smelt larvae. Results found that for survivorship of embryos and larvae within creosote environments were more sensitive than the two EPA species.
OS25M-25
A Probablistic Human Health Risk Assessment of Three National Estuarine Research Reserves
Through-out much of the United States coastal areas have been over-developed and over-exploited. Protective management strategies such as the National Estuarine Research Reserve (NERR) Program have been developed to promote education and coastal stewardship while monitoring how human activities and natural events change ecosystems. However, it is necessary to measure how anthropogenic activities in adjacent communities to NERR sites are affecting these protective areas and in turn posing a risk to human health. In this study a human health risk assessment will be conducted to evaluate the potential for exposure to concentrations of selected metals in water and sediments in the Grand Bay NERR, Apalachicola Bay NERR, and the ACE Basin NERR. This assessment will be achieved by using the Monte Carlo method evaluating residential exposure pathways associated with contaminated soil and groundwater including ingestion. Exposure calculations are performed using models present in the Environmental Protection Agency's Risk Assessment Guidance for Superfund Sites.