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Shaw K.S.,University of Cambridge | Jacobs J.M.,National Centers for Coastal Ocean Science | Crump B.C.,University of Cambridge | Crump B.C.,Oregon State University
Frontiers in Microbiology | Year: 2014

To determine if a storm event (i.e., high winds, large volumes of precipitation) could alter concentrations of Vibrio vulnificus and V. parahaemolyticus in aquacultured oysters (Crassostrea virginica) and associated surface water and sediment, this study followed a sampling timeline before and after Hurricane Irene impacted the Chesapeake Bay estuary in late August 2011. Aquacultured oysters were sampled from two levels in the water column: surface (0.3 m) and near-bottom (just above the sediment). Concentrations of each Vibrio spp. and associated virulence genes were measured in oysters with a combination of real-time PCR and most probable number (MPN) enrichment methods, and in sediment and surface water with real-time PCR. While concentration shifts of each Vibrio species were apparent post-storm, statistical tests indicated no significant change in concentration for either Vibrio species by location (surface or near bottom oysters) or date sampled (oyster tissue, surface water, and sediment concentrations). V. vulnificus in oyster tissue was correlated with total suspended solids (r = 0.41, P = 0.04), and V. vulnificus in sediment was correlated with secchi depth (r = -0.93, P <0.01), salinity (r = -0.46, P = 0.02), tidal height (r = -0.45, P = 0.03), and surface water V. vulnificus (r = 0.98, P <0.01). V. parahaemolyticus in oyster tissue did not correlate with environmental measurements, but V. parahaemolyticus in sediment and surface water correlated with several measurements including secchi depth [r = -0.48, P = 0.02 (sediment); r = -0.97, P <0.01 (surface water)] and tidal height [r = -0.96, P <0.01 (sediment), r = -0.59, P <0.01 (surface water)]. The concentrations of Vibrio spp. were higher in oysters relative to other studies (average V. vulnificus 4 × 105 MPN g-1, V. parahaemolyticus 1 × 105 MPN g-1), and virulence-associated genes were detected in most oyster samples. This study provides a first estimate of storm-related Vibrio density changes in oyster tissues, sediment, and surface water at an aquaculture facility in the Chesapeake Bay © 2014 Shaw, Jacobs and Crump. Source

Weijerman M.,University of Hawaii at Manoa | Weijerman M.,Wageningen University | Birkeland C.,University of Hawaii at Manoa | Piniak G.A.,National Centers for Coastal Ocean Science | And 6 more authors.
Current Opinion in Environmental Sustainability | Year: 2014

Determining whether a species warrants listing as threatened or endangered under the U.S. Endangered Species Act depends on the government's assessment of the species' extinction risk, usually in response to a petition. Deciding whether data are sufficient to make a listing determination is a challenging part of the process. We examined three case studies involving corals. A petition for deep-sea corals was rejected for full status review of the species, based on insufficient information on population trends and threats. Information on threats for 82 tropical corals was sufficient to propose listing of 66 species. Significant population declines and identified threats resulted in listing two Atlantic Acropora corals as 'Threatened'. There was no decrease in journal publication rate on the Acropora species after that listing, and no decrease in research permit applications in marine protected areas. However, the effects of listings on research that might help to sustain or recover species remains largely unknown. © 2013 Elsevier B.V. Source

Reiter M.A.,Bethune-Cookman University | Matlock G.C.,National Oceanic and Atmospheric Administration | Gentile J.H.,Harwell Gentile and Associates | Harwell M.A.,Harwell Gentile and Associates | And 4 more authors.
Journal of Environmental Assessment Policy and Management | Year: 2013

Ecosystem management requires understanding society's goals for an ecosystem and managing for some optimal solution. Unlike terrestrial ecosystem managers, coastal and marine ecosystem management seldom integrates across sectors or scientific disciplines to achieve desired social benefits. An Integrated Ecosystem Assessment (IEA) considers the ecosystem (including humans) as a unit and can assist in setting goals, determining an ecosystem's ability to support ecological processes and society's desires, and predicting the outcome of alternatives. The use of Coupled Ecological-Societal Systems Models utilised within the Integrated Assessment and Ecosystem Management Protocol (IAEMP) allows managers to extend a graphical picture of risk hypotheses to forecast scenarios that can be analysed relative to management goals. Scenarios predicted to meet management goals are evaluated against management constraints to select the "optimal" option for a management action in an adaptive management process. The IAEMP thus helps characterise potential causes of environmental problems, select appropriate response options, and implement and evaluate the selected option, thereby either addressing the concern or improving the ecosystem model for future decisions. © 2013 Imperial College Press. Source

Vollmer N.L.,University of Louisiana at Lafayette | Vollmer N.L.,National Oceanic and Atmospheric Administration | Viricel A.,University of Louisiana at Lafayette | Viricel A.,National Oceanic and Atmospheric Administration | And 3 more authors.
Current Genetics | Year: 2011

In population genetics and phylogenetic studies, mitochondrial DNA (mtDNA) is commonly used for examining differences both between and within groups of individuals. For these studies, correct interpretation of every nucleotide position is crucial but can be complicated by the presence of ambiguous bases resulting from heteroplasmy. Particularly for non-model taxa, the presence of heteroplasmy in mtDNA is rarely reported, therefore, it is unclear how commonly it occurs and how it can affect phylogenetic relationships among taxa and the overall understanding of evolutionary processes. We examined the occurrence of both site and length heteroplasmy within the mtDNA of ten marine mammal species, for most of which mtDNA heteroplasmy has never been reported. After sequencing a portion of the mtDNA control region for 5,062 individuals, we found heteroplasmy in at least 2% of individuals from seven species, including Stenella frontalis where 58.9% were heteroplasmic. We verified the presence of true heteroplasmy, ruling out artifacts from amplification and sequencing methods and the presence of nuclear copies of mitochondrial genes. We found no evidence that mtDNA heteroplasmy influenced phylogenetic relationships, however, its occurrence does have the potential to increase the genetic diversity for all species in which it is found. This study stresses the importance of both detecting and reporting the occurrence of heteroplasmy in wild populations in order to enhance the knowledge of both the introduction and the persistence of mutant mitochondrial haplotypes in the evolutionary process. © 2011 Springer-Verlag. Source

People can be affected by ciguatera, the most common form of algal-induced seafood poisoning, by eating contaminated tropical marine reef fish such as grouper, snapper and barracuda. The fish can become contaminated with ciguatoxins, potent neurotoxins produced by Gambierdiscus, a microscopic algae common in the tropics. Ciguatera-causing algae are abundant in the Caribbean, and ocean warming would enable some of those species to move northward, increasing its presence in the Gulf of Mexico and U.S. southeast Atlantic. Warmer temperatures could also mean larger and longer blooms of harmful algae, including those that produce ciguatoxins. In the Caribbean, Gambierdiscus are already near the top of their preferred temperature range. Higher temperatures are likely to inhibit the growth of these cells, slightly decreasing the risk of ciguatera in the Caribbean. "This is another example of how we can use NOAA's observing and forecasting expertise to anticipate and prepare for environmental change and its impact on coastal communities and economies," said Mary Erickson, director of NOAA's National Centers for Coastal Ocean Science, which conducted the research. "It contributes to NOAA's larger efforts to build a 'climate-smart' nation resilient to climate and weather extremes, and long-term changes." For this study, researchers projected water temperatures in the greater Caribbean through the year 2099, based on 11 global climate models and data from NOAA buoys in the Caribbean and Gulf of Mexico. Forecasted temperature changes were then used to project the effects of ocean warming on the growth, abundance and distribution of two groups of ciguatera-causing algae (Gambierdiscus and Fukuyoa). More than 400 fish species are known to become toxic. In U.S. waters, ciguatera occurs in Hawaii, Guam, southern Florida, Puerto Rico, the U.S. Virgin Islands, and occasionally in the Gulf of Mexico, extending around the southeast U.S. coast as far north as North Carolina. Ciguatera impedes development of fisheries resources in many regions of the world. Toxins produced by Gambierdiscus contaminate marine animals such as corals and seaweeds, and the carnivores that feed upon them, causing toxins to move into the food chain. "Contaminated fish have no specific taste, color, or smell and there is no easy method for measuring ciguatoxins," said Steve Kibler, a NOAA scientist and the study's lead author. "However, we can forecast risk based on where and when we are likely to find the algae that produce ciguatoxins." The forecast will allow communities to target monitoring, saving resources by focusing only on areas and times when ciguatera is likely to be present. This work is part of a larger NOAA effort to develop and implement practical, affordable, and sustainable strategies for managing the risk of ciguatera. Next steps include determining which species are producing the toxins and developing and transferring monitoring technology to managers and researchers in tropical countries around the world. The ciguatera forecast is part of a NOAA ecological forecasting initiative that aims to deliver accurate, relevant, timely and reliable ecological forecasts directly to coastal resource managers and the public as part of its stewardship and scientific mandates for coastal, marine and Great Lakes resources. More information: Steven R. Kibler et al. Effects of ocean warming on growth and distribution of dinoflagellates associated with ciguatera fish poisoning in the Caribbean, Ecological Modelling (2015). DOI: 10.1016/j.ecolmodel.2015.08.020

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