Showing papers by "National Ocean Service published in 2002"
TL;DR: Risk analyses for dolphin populations near Beaufort, Sarasota, and Matagorda Bay indicate a high likelihood that reproductive success, primarily in primiparous females, is being severely impaired by chronic exposure to PCBs.
Abstract: High levels of polychlorinated biphenyls (PCBs) have been reported in the tissues of some species of marine mammals. The high concentrations are of concern because a growing body of experimental evidence links PCBs to deleterious effects on reproduction, endocrine homeostasis, and immune system function. Much of the recent research has focused on determining the exposure of marine mammal populations to PCBs, but very little effort has been devoted to the actual risk assessments that are needed to determine the expected impacts of the documented exposures. We describe a novel risk assessment approach that integrates measured tissue concentrations of PCBs with a surrogate dose-response relationship and leads to predictions of health risks for marine mammals as well as to the uncertainties associated with these predictions. Specifically, we use PCB tissue residue data from three populations of bottlenose dolphins (Tursiops truncatus), study the feasibility of published dose-response data from a surrogate species. and combine this information to estimate the risk of detrimental reproductive effects in female dolphins. Our risk analyses for dolphin populations near Beaufort (NC, USA), Sarasota (FL, USA), and Matagorda Bay (TX, USA) indicate a high likelihood that reproductive success, primarily in primiparous females, is being severely impaired by chronic exposure to PCBs. Excess risk of reproductive failure, measured in terms of stillbirth or neonatal mortality, for primiparous females was estimated as 60% (Beaufort), 79% (Sarasota), and 78% (Matagorda Bay). Females of higher parity, which have previously off-loaded a majority of their PCB burden, exhibit a much lower risk.
173 citations
TL;DR: It is hypothesized that CFB bacteria may be successfully competing with 41-DBG2 (also a member of the CFB) for nutrients, thereby inhibiting growth of the latter and indirectly providing resistance against algicidal attack.
140 citations
TL;DR: Examination of fine‐scale population structure and paternal contribution to loggerhead clutches on Melbourne Beach, FL, USA using microsatellite markers concludes that males are not a limiting resource for this central Florida nesting aggregate.
Abstract: Many aspects of sea turtle biology are difficult to measure in these enigmatic migratory species, and this lack of knowledge continues to hamper conservation efforts. The first study of paternity in a sea turtle species used allozyme analysis to suggest multiple paternity in loggerhead turtle (Caretta caretta) clutches in Australia. Subsequent studies indicated that the frequency of multiple paternity varies from species to species and perhaps location to location. This study examined fine-scale population structure and paternal contribution to loggerhead clutches on Melbourne Beach, FL, USA using microsatellite markers. Mothers and offspring from 70 nests collected at two locations were analysed using two to four polymorphic microsatellite loci. Fine-scale population differentiation was not evident between the sampled locations, separated by 8 km. Multiple paternity was common in loggerhead nests on Melbourne Beach; 22 of 70 clutches had more than one father, and six had more than two fathers. This is the first time that more than two fathers have been detected for offspring in individual sea turtle nests. Paternal genotypes could not be assigned with confidence in clutches with more than two fathers, leaving the question of male philopatry unanswered. Given the high incidence of multiple paternity, we conclude that males are not a limiting resource for this central Florida nesting aggregate.
103 citations
TL;DR: The collected data show that pyrogenic PAHs were highly associated with biological effects on benthic organisms, based on bioassay results.
Abstract: Surface sediments collected from the Savannah River, located in the southeastern state of Georgia, USA, in June–July 1994 were analyzed for individual polycyclic aromatic hydrocarbons (PAHs). Three subdivisions of the river were identified for the study: upstream from, adjacent to, and downstream from the city of Savannah. There was high spatial variability in the total PAH (ΣPAH) concentrations that ranged from 29 to 5,375 ng/g with an average concentration of 1,216 ± 1,161 (SD). Of the three subdivisions, the highest ΣPAH concentrations were in the middle segment, which was adjacent to urban and industrial areas. To elucidate sources, molecular indices based on indices among phenanthrene versus anthracene and fluoranthene versus pyrene were used to determine pyrogenic and petrogenic sources, respectively. These indices have been used by other authors to differentiate sources. In most cases, PAHs in sediments nearest the city of Savannah were of high temperature and pyrogenic origin. These pyrogenic PAHs were highly associated with toxicity to benthic organisms. The two-ringed naphthalene and substituted naphthalenes, which are petroleum-related PAHs, were significantly higher in the lower section of the river relative to the subdivisions. This river segment receives inputs primarily from shipping and boating traffic. Perylene, which is indicative of nonanthropogenic terrestrial inputs of carbon, had the highest concentration among the individual PAHs measured. High perylene concentrations were found at stations located upstream and adjacent to forested terrain and where salinity level was low. To discriminate pattern differences and similarities of individual PAHs among samples, principal component analysis (PCA) was performed on the more hydrophobic and persistent nonalkylated PAHs. These differences and similarities were used to infer perylene origin. PCA was performed on 14 nonalkylated PAHs that was normalized to the sum of nonalkylated PAHs, using a correlation matrix. Generally, the PAHs were separated into group patterns according to chemical and physical properties associated with log K
OW, except perylene. Perylene, a five-ringed PAH, was distinctly separated from the other five-ringed PAHs. The sources for perylene are likely from biogenic, terrestrial precursors. The collected data show that pyrogenic PAHs were highly associated with biological effects on benthic organisms, based on bioassay results. Perylene, a nonanthropogenic PAH, was found throughout the river and constituted a large percentage of total PAHs in the upper river.
84 citations
TL;DR: A rigorous examination of the life cycle of P. piscicida using nuclear staining techniques combined with high‐resolution video microscopy, EM, and in situ hybridization with a suite of fluorescently labeled peptide nucleic acid (PNA) probes showed that it had a typical haplontic dinoflagellate life cycle.
Abstract: The putatively toxic dinoflagellate Pfiesteria piscicida (Steidinger et Burkholder) has been reported to have an unusual life cycle for a free-living marine dinoflagellate. As many as 24 life cycle stages were originally described for this species. During a recent phylogenetic study in which we used clonal cultures of P. piscicida, we were unable to confirm many reported life cycle stages. To resolve this discrepancy, we undertook a rigorous examination of the life cycle of P. piscicida using nuclear staining techniques combined with traditional light microscopy, high-resolution video microscopy, EM, and in situ hybridization with a suite of fluorescently labeled peptide nucleic acid (PNA) probes. The results showed that P. piscicida had a typical haplontic dinoflagellate life cycle. Asexual division occurred within a division cyst and not by binary fission of motile cells. Sexual reproduction of this homothallic species occurred via the fusion of isogamous gametes. Examination of tanks where P. piscicida was actively feeding on fish showed that amoebae were present; however, they were contaminants introduced with the fish. Whole cell probing using in situ hybridization techniques confirmed that these amoebae were hybridization negative for a P. piscicida-specific PNA probe. Direct observations of clonal P. piscicida cultures revealed no unusual life cycle stages. Furthermore, the results of this study provided no evidence for transformations to amoebae. We therefore conclude that P. piscicida has a life cycle typical of free-living marine dinoflagellates and lacks any amoeboid or other specious stages.
80 citations
TL;DR: The objective of this study was to determine inorganic and organic contaminant concentrations in edible tissue of fish collected from eight coastal areas receiving wastewater discharges and from two reference locations, and trace metal residues were statistically similar regardless of the collection site.
75 citations
TL;DR: In this article, a multibeam high-resolution bathymetric survey of the channels between the islands, coupled with observations and video-transects utilizing DeepWorker-2000 submersibles, has revealed the existence of numerous drowned reef features including concentric solution basins, solution ridges (rims), sand and sediment plains, and conical-shaped reef pinnacles.
Abstract: During the last glacial maximum (LGM), about 21,000 years ago, the Hawaiian Islands of Maui, Lanai, and Molokai were interconnected by limestone bridges, creating a super-island known as Maui-Nui. Approximately 120 m of sea-level rise during the Holocene Transgression flooded, and then drowned, these bridges separating the islands by inter-island channels. A new multibeam high-resolution bathymetric survey of the channels between the islands, coupled with observations and video-transects utilizing DeepWorker-2000 submersibles, has revealed the existence of numerous drowned reef features including concentric solution basins, solution ridges (rims), sand and sediment plains, and conical-shaped reef pinnacles. The concentric basins contain flat lagoon-like bottoms that are rimmed by steep-sided limestone walls. Undercut notches rim the basins at several depths, marking either sea-level still stands or paleo-lake levels. All of the solution basins shallower than 120 m were subaerial at the LGM, and at one stage or another may have been shallow shoreline lakes. Today, about 70 drowned reef pinnacles are scattered across the Maui–Lanai underwater bridge and all are situated in wave-sheltered positions. Most drowned during the interval between 14,000 and 10,000 years ago when sea-level rise averaged 15 mm/year. Virtually all of the surficial topography in the Au'au Channel today is a product of karst processes accentuated by marginal reef growth during the Holocene. Both the submerged basins and the drowned reefs represent an archive of sea-level and climate history in Hawaii during the late Quaternary.
75 citations
01 Jul 2002
TL;DR: Aysen Fjord transect was sampled using acoustic doppler current profiler (ADCP) during 20 repetitions during one semidiurnal tidal cycle as mentioned in this paper.
Abstract: Measurements of velocity and density profiles were made to describe the transverse structure of the flow in Aysen Fjord, Southern Chile (45.2°S and 73.3°W). Current profiles were made with a 307.2 kHz acoustic doppler current profiler (ADCP) during 20 repetitions of a cross-fjord transect during one semidiurnal tidal cycle. The transect had a ∼320° orientation, 3 km length, and its bathymetry consisted of two channels, one on the southern side (230 m depth) and the other on the northern side (180 m depth), separated by a bank ca. 65 m depth, which was located ∼1 km from the northern coast. Density measurements to a maximum depth of 50 m were made at the extremes of each transect repetition and over the bank. Also, a total of nine CTD stations that covered the surroundings of the bank was sampled 2 days prior to the ADCP sampling. During the sampling period the mean flow showed a three layer structure that was consistent with up-fjord wind-induced exchange: a thin (
64 citations
TL;DR: It is determined by HPLC-UV and receptor binding assay, with confirmation by LC-MS/MS, that sand crabs accumulated measurable amounts of DA during toxic Pseudo-nitzschia blooms, while the sea mussel showed no detectable toxin.
57 citations
TL;DR: The results of substrate specificity and cholinesterase inhibition in grass shrimp indicate that acetylthiocholine iodide is the most appropriate substrate for assessing cholineterases inhibition ingrass shrimp.
46 citations
TL;DR: The rise and fall of DA in sand crabs in synchrony with Pseudo-nitzschia abundance, combined with this common intertidal species' accessibility and ease of DA extraction, clearly indicate the utility of sand crabs as a reliable, cost-effective monitoring tool for DA in the nearshore coastal environment.
TL;DR: In this article, a method was developed for spatially interpolating tidal constituent amplitude and phase data using the numerical solution of Laplace's equation, which matches the input data values at "internal boundaries", i.e., locations that represent observation stations.
Abstract: A method was developed for spatially interpolating tidal constituent amplitude and phase data using the numerical solution of Laplace's equation. The solution matches the input data values at ‘ internal boundaries ’, i.e., locations that represent observation stations. The boundary condition at land-water interfaces assumes that the normal derivative is proportional to the spatially-averaged value of the derivative in the normal direction. By adjusting the constant of proportionality at land boundaries, realistic distributions were obtained. An equivalent solution field can also be reconstructed by generating a set of weighting functions, thereby minimizing the number of solution fields needed. The method was tested in a simple basin and the solution was evaluated for a variety of parameters such as cell size, grid orientation, and boundary proportionality constant. The method was then applied to San Francisco Bay and distributions of tidal constituent amplitudes and epochs were compared with those generated by a numerical circulation model.
TL;DR: A new species of planktonic dinoflagellate, Prorocentrum arabianum isolated from the Gulf of Oman, is described using both scanning electron microscopy (SEM) and light microscopy and confirms the production of one cytotoxic compound and one ichthyotoxic compounds.
TL;DR: In this article, the Chesapeake Bay Benthic Index of Biotic Integrity (B-IBI) and the Environmental Monitoring and Assessment Program (EMAP-VP BI) were compared.
Abstract: SUMMARY The Chesapeake Bay Benthic Index of Biotic Integrity (B-IBI) and the Environmental Monitoring and Assessment Program’s Virginian Province Benthic Index (EMAP-VP BI) were applied to 294 sampling events in Chesapeake Bay and the results were compared. These estuarine benthic indices are intended to identify benthic invertebrate assemblages that have been degraded by low dissolved oxygen concentrations or high concentrations of chemical contaminants. The B-IBI includes several community measures and weights them equally using a simple scoring system that compares them against values expected for undegraded sites. It includes 11 measures of species diversity, productivity, indicator species and trophic composition. The EMAP-VP BI uses discriminant function coefficients to weight contributions of species diversity and the abundances of two indicator families. The two indices agreed on degraded or undegraded classifications for benthos at 81.3% of the sites. This level of agreement is within the level of accuracy achieved during index development and, therefore, may approach the limits that can be achieved. The indices were strongly associated (Pearson’s r ¼ 0.75). The B-IBI was more conservative than the EMAP-VP BI, classifying 72.7% of the disagreements as degraded. The 55 sites where the indices disagreed were distributed in different habitats throughout the Bay except polyhaline sand. Many of the classification disagreements were at sites with index values close to, but on opposite sides of, the degraded–undegraded thresholds, with 49.1% of the B-IBI values within 0.5 units and 81.8% within 1.0 units; the corresponding values for sites where both indices agreed were only 23.4% and 62.7%, respectively. The pattern for the EMAP-VP BI was similar, with 61.8% and 74.6% of disagreements and only 18.8% and 38.9% of agreements within 0.5 and 1.0 units of the threshold. Although the close agreement suggests that either index is suitable for evaluating the benthic condition, the B-IBI offers some additional advantages. Copyright # 2002 John Wiley & Sons, Ltd.
TL;DR: Results indicate that sublethal endosulfan concentrations may have a negative effect on grass shrimp reproductive biology.
TL;DR: Concentrations of eight trace elements, lindane, and six groups of organic contaminants at the 11 NOAA mussel watch project (MWP) sites located in North and South Carolina have been compared with the national US MWP data.
TL;DR: In this article, an adjoint data assimilation system was developed to assimilate coastal subtidal water level data into a hydrodynamic model, where the wind drag coefficient was used as a convenient control variable (approximately representing errors in the forecasting wind fields that are usually the primary cause of errors in model-produced water levels).
Journal Article•
TL;DR: In this paper, a vertical datum transformation tool, VDatum, has been developed which allows transformation among 27 different orthometric, 3-D/ellipsoid, and tidal datums.
Abstract: The integration of bathymetry, topography, and shoreline is beneficial for a number of coastal applications. This geospatial integration begins with the blending of bathymétrie and topographic data into a digital elevation model (DEM) after all data sets have been transformed to a common vertical datum. A vertical datum transformation tool, VDatum, has been developed which allows transformation among 27 different orthometric, 3-D/ellipsoid, and tidal datums. The geographic distribution of the tidal datums in VDatum are produced with a calibrated hydrodynamic tidal model. An initial demonstration project was carried out in the Tampa Bay region where the bathymétrie data from NOAA (US National Oceanic and Atmospheric Administration) was blended with the topographic data from USGS (US Geological Survey). One objective was to solve the problem of inconsistencies between NOAA's nautical charts and USGS's mapping products, especially with respect to shoreline. A method was demonstrated for determining a consistently defined mean high water (MHW) shoreline from high-resolution Lidar elevation data covering the intertidal zone after transformation of these data to the MHW datum (with the zero contour being the MHW shoreline). VDatum will also play a key role in: (1) the implementation of a seamless high-resolution National Bathymétrie Database, which will support both the production of ENCs (Electronic Navigational Charts) and the GIS-based activities of coastal zone managers; (2) the ability to use quality 3rd-party bathymétrie data, which in the past was a problem due to the many different datums in use; (3) marine boundary determination; and (4) the on-the-fly measurement of bathymétrie data relative to chart datum (Mean Lower Low Water) in future hydrographic surveys, using VDatum to transform the RTK-GPS-referenced data to MLLW.
01 Jul 2002
TL;DR: In this paper, a 4 element mooring array collected in a bend of a shallow, sinuous estuary is used to describe the flow, density structure and momentum balance over a 10-day period.
Abstract: Observations from a 4 element mooring array collected in a bend of a shallow, sinuous estuary are used to describe the flow, density structure and momentum balance over a 10-day period. In general, the flow in the lower 3 m is stratified on ebb and unstratified on flood and shear is concentrated near the bed on flood and nearly uniform throughout the water column on ebb. At spring tides stratification is reduced and the flows 1 m above bottom (mab) are consistently greatest at the downstream end of the bend. The along-channel density gradient is weakest during spring tides owing to zero gradient over most of ebb flow. At neap tides vertical stratification is strong enough to raise the gradient Richardson number well above 0.25 for most of the ebb tide. Currents are weaker and do not display a regular along-channel pattern. The variation in density and current structure is interpreted to result from variations in cross-channel circulation associated with the channel bend. At spring tides, the cross-channel circulation appears to be strong enough to overturn the water column whereas at neap tides stratification is strong enough to halt the overturning. Reynolds stress measured with a Benthic Acoustic Stress Sensor undergoes a four-fold increase between neap and spring tide. The drag coefficient relative to flow at 1 mab is 0.0015–0.0025. Bed stress in the bend is estimated using this drag coefficient and the maximum instantaneous velocity at 1 mab over the array. Because of the along-channel variability in current speed, the estimated bed stress is roughly twice as large as the measured Reynolds stress in the middle of the bend. The estimated bed stress is found to balance the horizontal pressure gradient and local acceleration, implying that a depth-averaged linear momentum balance adequately describes the dynamics on the bend when the impact of the cross-channel circulation is taken into account in the estimate of the bottom stress.
TL;DR: In this article, a study of ecological conditions associated with bottom sediments in the Neuse Riverestuary, U.S.A. was undertaken during summer1998, where the distribution and condition of benthic infauna were found to vary in response to natural and anthropogenic factors, and apparent associations between degraded infaunalcondition and sediment contamination and/ortoxicity were observed over roughly half of the sampled area.
Abstract: A study of ecological conditions associatedwith bottom sediments in the Neuse Riverestuary, U.S.A. was undertaken during summer1998. Sampling of macroinfauna, sedimentsfor toxicity and chemical contaminant analyses,and physical properties of water was carriedout synoptically over a four-day period at 20stations from the mouth of the Neuse River atPamlico Sound to approximately 90 km upstream. The distribution and condition of benthicinfauna were found to vary in response tonatural and anthropogenic factors, and apparentassociations between degraded infaunalcondition and sediment contamination and/ortoxicity were observed over roughly half of thesampled area (7 stations, 47% area). With fewexceptions, degraded benthic conditions wereassociated with significant sedimentcontamination or toxicity. High sedimentcontaminant levels were found to occur almostexclusively in fine-grained, organic-rich muds. These results suggest that high organic loadingand chemical contaminant inputs to the NeuseRiver, coupled with low freshwater dischargerates and high residence times in the lowerestuary, have contributed to degraded benthicconditions at these sites.
TL;DR: Since its identification, the dinoflagellate Pfiesteria piscicida has been implicated in fish kills and fish disease in the southeastern United States and in watermen following exposure to a fish kill in Maryland.
TL;DR: The real-time, three-dimensional, limited-area Coastal Ocean Forecast System (COFS) has been developed for the northwestern Atlantic Ocean and implemented at the National Centers for Environmental Prediction as discussed by the authors.
Abstract: The real-time, three-dimensional, limited-area Coastal Ocean Forecast System (COFS) has been developed for the northwestern Atlantic Ocean and implemented at the National Centers for Environmental Prediction. COFS generates a daily nowcast and 1-day forecast of water level, temperature, salinity, and currents. Surface forcing is provided by 3-h forecasts from the National Weather Service's Eta Model, a mesoscale atmospheric prediction model. Lateral oceanic boundary conditions are based on climatic data. COFS assimilates in situ sea surface temperature (SST) observations and multichannel satellite SST retrievals for the past 48 h. SST predictions from the assimilating and nonassimilating versions of COFS were compared with independent observations and a 14-km-resolution multichannel SST analysis. The assimilation of SST data reduced the magnitude and the geographic extent of COFS's characteristic positive temperature bias north of the Gulf Stream. The root-mean-square SST differences between the ...
TL;DR: Results from this study indicate that the PKA in A. operculatum has a catalytic subunit of similar size to that in higher eukaryotes, but with a holoenzyme of a size suggesting a dimeric, rather than tetrameric structure.
Abstract: A cAMP dependent protein kinase (PKA) was identified in the dinoflagellate Amphidinium operculum. In vitro kinase activity towards kemptide, a PKA-specific substrate, was not detectable in crude lysates. However, fractionation of dinoflagellate extracts by gel filtration chromatography showed PKA-like activity toward kemptide at approximately 66 kDa. These findings suggest that possible low molecular mass inhibitors in crude lysates were removed by the gel filtration chromatography. Pre-incubation of extracts with cAMP prior to chromatography resulted in an apparent molecular mass shift in the in vitro kinase assay to 40 kDa. An in-gel kinase assay reflected activity of the free catalytic subunit at approximately 40 kDa. Furthermore, western blotting with an antibody to the human PKA catalytic subunit confirmed a catalytic subunit with a mass of approximately 40 kDa. Results from this study indicate that the PKA in A. operculatum has a catalytic subunit of similar size to that in higher eukaryotes, but with a holoenzyme of a size suggesting a dimeric, rather than tetrameric structure.
TL;DR: The results stress the importance of taking into account the potential presence of PSTs in size fractions other than that containing the known algal producer when attempting to model shellfish intoxication, especially during years of low cell abundance.
TL;DR: A rebuttal of Burkholder and Glasgow's criticisms is presented and a simple way to resolve the discrepancies in the P. piscicida life cycle is suggested.
Abstract: Free-living, marine dinoflagellates are typified by a well-defined, haplontic life cycle with relatively few stages. The most unusual departure from this life cycle is one reported for the heterotrophic dinoflagellate Pfiesteria piscicida Steidinger et Burkholder. This species is alleged to have at least 24 life cycle stages including amoebae and a chrysophyte-like cyst form (Burkholder et al. 1992, Burkholder and Glasgow 1997a) not previously known in free-living marine dinoflagellates. Litaker et al. (2002) redescribed the life cycle of P. piscicida from single-cell isolates and found only life cycle stages typical of free-living marine dinoflagellates. The discrepancy between these observations and the life cycle reported in the literature prompted a rigorous study to resolve the life cycle of P. piscicida.Burkholder and Glasgow (2002) took exception to this study, arguing that Litaker et al. (2002) misunderstood the life cycle of P. piscicida and ignored recent publications. We present a rebuttal of their criticisms and suggest a simple way to resolve the discrepancies in the P. piscicida life cycle.