Showing papers by "National Ocean Service published in 2012"

Modelling sea level rise impacts on storm surges along US coasts

Abstract: Sound policies for protecting coastal communities and assets require good information about vulnerability to flooding. Here, we investigate the influence of sea level rise on expected storm surge-driven water levels and their frequencies along the contiguous United States. We use model output for global temperature changes, a semi-empirical model of global sea level rise, and long-term records from 55 nationally distributed tidal gauges to develop sea level rise projections at each gauge location. We employ more detailed records over the period 1979‐2008 from the same gauges to elicit historic patterns of extreme high water events, and combine these statistics with anticipated relative sea level rise to project changing local extremes through 2050. We find that substantial changes in the frequency of what are now considered extreme water levels may occur even at locations with relatively slow local sea level rise, when the difference in height between presently common and rare water levels is small. We estimate that, by mid-century, some locations may experience high water levels annually that would qualify today as ‘century’ (i.e., having a chance of occurrence of 1% annually) extremes. Today’s century levels become ‘decade’ (having a chance of 10% annually) or more frequent events at about a third of the study gauges, and the majority of locations see substantially higher frequency of previously rare storm-driven water heights in the future. These results add support to the need for policy approaches that consider the non-stationarity of extreme events when evaluating risks of adverse climate impacts.

Quantifying Loss of Acoustic Communication Space for Right Whales in and around a U.S. National Marine Sanctuary

Abstract: The effects of chronic exposure to increasing levels of human-induced underwater noise on marine animal populations reliant on sound for communication are poorly understood. We sought to further develop methods of quantifying the effects of communication masking associated with human-induced sound on contact-calling North Atlantic right whales (Eubalaena glacialis) in an ecologically relevant area (~10,000 km(2) ) and time period (peak feeding time). We used an array of temporary, bottom-mounted, autonomous acoustic recorders in the Stellwagen Bank National Marine Sanctuary to monitor ambient noise levels, measure levels of sound associated with vessels, and detect and locate calling whales. We related wind speed, as recorded by regional oceanographic buoys, to ambient noise levels. We used vessel-tracking data from the Automatic Identification System to quantify acoustic signatures of large commercial vessels. On the basis of these integrated sound fields, median signal excess (the difference between the signal-to-noise ratio and the assumed recognition differential) for contact-calling right whales was negative (-1 dB) under current ambient noise levels and was further reduced (-2 dB) by the addition of noise from ships. Compared with potential communication space available under historically lower noise conditions, calling right whales may have lost, on average, 63-67% of their communication space. One or more of the 89 calling whales in the study area was exposed to noise levels ≥120 dB re 1 μPa by ships for 20% of the month, and a maximum of 11 whales were exposed to noise at or above this level during a single 10-min period. These results highlight the limitations of exposure-threshold (i.e., dose-response) metrics for assessing chronic anthropogenic noise effects on communication opportunities. Our methods can be used to integrate chronic and wide-ranging noise effects in emerging ocean-planning forums that seek to improve management of cumulative effects of noise on marine species and their habitats.

Nitrogen limitation increases brevetoxins in karenia brevis (dinophyceae): implications for bloom toxicity(1).

Abstract: Laboratory and field measurements of the toxin content in Karenia brevis cells vary by >4-fold. These differences have been largely attributed to genotypic variations in toxin production among strains. We hypothesized that nutrient limitation of growth rate is equally or more important in controlling the toxicity of K. brevis, as has been documented for other toxic algae. To test this hypothesis, we measured cellular growth rate, chlorophyll a, cellular carbon and nitrogen, cell volume, and brevetoxins in four strains of K. brevis grown in nutrient-replete and nitrogen (N)-limited semi-continuous cultures. N-limitation resulted in reductions of chlorophyll a, growth rate, volume per cell and nirtogen:carbon (N:C) ratios as well as a two-fold increase (1%-4% to 5%-9%) in the percentage of cellular carbon present as brevetoxins. The increase in cellular brevetoxin concentrations was consistent among genetically distinct strains. Normalizing brevetoxins to cellular volume instead of per cell eliminated much of the commonly reported toxin variability among strains. These results suggest that genetically linked differences in cellular volume may affect the toxin content of K. brevis cells as much or more than innate genotypic differences in cellular toxin content per unit of biomass. Our data suggest at least some of the >4-fold difference in toxicity per cell reported from field studies can be explained by limitation by nitrogen or other nutrients and by differences in cell size. The observed increase in brevetoxins in nitrogen limited cells is consistent with the carbon:nutrient balance hypothesis for increases in toxins and other plant defenses under nutrient limitation.

A long-term monitoring study of chlorophyll, microbial contaminants, and pesticides in a coastal residential stormwater pond and its adjacent tidal creek.

Abstract: Stormwater ponds are commonly used in residential and commercial areas to control flooding. The accumulation of urban contaminants in stormwater ponds can lead to water-quality problems including nutrient enrichment, chemical contamination, and bacterial contamination. This study presents 5 years of monitoring data assessing water quality of a residential subdivision pond and adjacent tidal creek in coastal South Carolina, USA. The stormwater pond is eutrophic, as described by elevated concentrations of chlorophyll and phosphorus, and experiences periodic cyanobacterial blooms. A maximum monthly average chlorophyll concentration of 318.75 μg/L was measured in the stormwater pond and 227.63 μg/L in the tidal creek. Fecal coliform bacteria (FCB) levels were measured in both the pond and the tidal creek that exceeded health and safety standards for safe recreational use. A maximum monthly average FCB level of 1,247 CFU/100 mL was measured in the stormwater pond and 12,850 CFU/100 mL in the tidal creek. In addition, the presence of antibiotic resistant bacteria and pathogenic bacteria were detected. Low concentrations of herbicides (atrazine and 2,4-D), a fungicide (chlorothalonil), and insecticides (pyrethroids and imidacloprid) were measured. Seasonal trends were identified, with the winter months having the lowest concentrations of chlorophyll and FCB. Statistical differences between the stormwater pond and the tidal creek were also noted within seasons. The tidal creek had higher FCB levels than the stormwater pond in the spring and summer, whereas the stormwater pond had higher chlorophyll levels than the tidal creek in the summer and fall seasons. Chlorophyll and FCB levels in the stormwater pond were significantly correlated with monthly average temperature and total rainfall. Pesticide concentrations were also significantly correlated with temperature and rainfall. Pesticide concentrations in the stormwater pond were significantly correlated with pesticide concentrations in the adjacent tidal creek. Chlorophyll and FCB levels in the tidal creek, however, were not significantly correlated with levels in the pond. While stormwater ponds are beneficial in controlling flooding, they may pose environmental and human health risks due to biological and chemical contamination. Management to reduce residential runoff may improve water quality in coastal stormwater ponds and their adjacent estuarine ecosystems.

Eutrophication Assessment in Basque Estuaries: Comparing a North American and a European Method

Abstract: Eutrophication in marine ecosystems is an important problem that requires an accurate assessment. Although Basque estuaries (northern Spain) have historically been under high anthropogenic pressure, no specific eutrophication assessment method had been applied in these waters. In this study, a method employed in the Basque Country (BC) to assess the “risk of failing to achieve good ecological status” under the requirements of the Water Framework Directive (WFD) was adapted to exclusively assess the risk of eutrophication. This method is based on the driver–pressure–state–impact–response approach. The results from this method (called WFD-BC method) were compared to the results from Assessment of Estuarine Trophic Status (ASSETS; a specific method developed in the US to assess estuarine trophic status in a pressure–state–response approach). The nutrient pressure was better characterized with the WFD-BC method due to the local hydrographic conditions (i.e., small and river-influenced estuaries) that were not well accommodated by the ASSETS method. In contrast, the WFD-BC results for assessment of state generally reflected worse conditions than the results from the ASSETS method due to the different indicators employed and the way these are integrated in the WFD-BC method. Overall, the WFD-BC method showed a good potential to assess eutrophication. However, to improve it, a lower weight for the benthos and macroalgae is recommended for evaluating state.

Phytoplankton blooms detected by SeaWiFS along the central and southern California coast

Abstract: [1] The effect of upwelling events, storm water discharge, and local circulation on phytoplankton blooms in the central California and Southern California Bight (SCB) coastal zones was analyzed using 10+ years (1997–2007) of remotely sensed surface chlorophyll concentration (CHL, derived from SeaWiFS ocean color), sea surface temperature, and modeled freshwater discharge. Analysis of variability and factors associated with phytoplankton blooms was conducted using the offshore extension of zones of CHL > 5 mg m−3; this method excludes terrestrial interference that complicates the use of ocean color to investigate phytoplankton blooms in coastal waters. In the SCB, blooms were most frequent in spring and associated with the spring transition to an upwelling regime. Along the Central Coast, blooms persisted from spring to autumn during seasonal intensification of upwelling. Offshore CHL extensions showed a significant positive trend during 1997–2007, with maxima in 2000–2001 and 2005–2006 that coincided with higher than normal frequency of upwelling events. Upwelling was found to be a major factor driving phytoplankton blooms, although the standard upwelling index derived from large-scale atmospheric circulation was decoupled from the frequencies of both upwelling events and phytoplankton blooms. Areas of longer residence time associated with natural boundaries between coastal ocean regions had more extensive and persistent blooms. The influence of storm water discharge on offshore CHL extension appeared to be limited to areas in close proximity to major river mouths. These “hot spots” were also co-located with ocean outfalls of Publicly Owned Treatment Works (POTW) discharge and, in some cases, longer residence time of coastal waters.

Comparative effects of the marine algal toxins azaspiracid-1, -2, and -3 on Jurkat T lymphocyte cells

Abstract: Azaspiracids (AZA) are polyether marine toxins of dinoflagellate origin that accumulate in shellfish and represent an emerging human health risk. Although monitored and regulated in many European and Asian countries, there are no monitoring programs or regulatory requirements in the United States for this toxin group. This did not prove to be a problem until June 2009 when AZAs were identified in US seafood for the first time resulting in human intoxications and further expanding their global distribution. Efforts are now underway in several laboratories to better define the effects and mechanism(s) of action for the AZAs. Our investigations have employed Jurkat T lymphocyte cells as an in vitro model to characterize the toxicological effects of AZA1, AZA2, and AZA3. Cytotoxicity experiments employing a metabolically based dye (i.e., MTS) indicated that AZA1, AZA2, and AZA3 each elicited a lethal response that was both concentration- and time-dependent, with EC(50) values in the sub- to low nanomolar range. On the basis of EC(50) comparisons, the order of potency was as follows: AZA2 > AZA3 > AZA1, with toxic equivalence factors (TEFs) relative to AZA1 of 8.3-fold and 4.5-fold greater for AZA2 and AZA3, respectively. Image analysis of exposed cells using Nomarski differential interference contrast (DIC) imaging and fluorescent imaging of cellular actin indicated that the morphological effects of AZA1 on this cell type are unique relative to the effects of AZA2 and AZA3. Collectively, our data support the growing body of evidence suggesting that natural analogues of AZA are highly potent and that they may have multiple molecular targets.

Elimination Kinetics of Domoic Acid from the Brain and Cerebrospinal Fluid of the Pregnant Rat

Abstract: Domoic acid (DA) causes neurological effects in multiple species upon exposure, including status epilepticus in pregnant sea lions and an epileptic disease state that commonly develops in juveniles. This study aims to define brain toxicokinetic parameters in the pregnant rat in the larger context of maternal-fetal toxin transfer. Specifically, Sprague-Dawley rats were exposed to a low observable effect level of 1.0 mg DA/kg intravenously at gestational day 20, and plasma, brain, and cerebrospinal fluid (CSF) samples were taken at discrete time points over 24 h. Domoic acid concentrations were determined by a tandem LC/MS method recently optimized for brain tissue and CSF. Data showed that 6.6% of plasma DA reached the brain, 5.3% reached the CSF, and DA levels were nearly identical in both brain and CSF for 12 h, remaining above the threshold to activate isolated hippocampal neurons for 2 h. The calculated terminal half-life of CSF was 4 h, consistent with the time for complete CSF regeneration, suggesting that CSF acts as a mechanism to clear DA from the brain.

Cryopreservation and in vitro culture of primary cell types from lung tissue of a stranded pygmy sperm whale (Kogia breviceps).

Abstract: Current models for in vitro studies of tissue function and physiology, including responses to hypoxia or environmental toxins, are limited and rely heavily on standard 2-dimensional (2-D) cultures with immortalized murine or human cell lines To develop a new more powerful model system, we have pursued methods to establish and expand cultures of primary lung cell types and reconstituted tissues from marine mammals What little is known about the physiology of the deep-sea diving pygmy sperm whale (PSW), Kogia breviceps, comes primarily from stranding events that occur along the coast of the southeastern United States Thus, development of a method for preserving live tissues and retrieving live cells from deceased stranded individuals was initiated This report documents successful cryopreservation of PSW lung tissue We established in vitro cultures of primary lung cell types from tissue fragments that had been cryopreserved several months earlier at the stranding event Dissociation of cryopreserved lung tissues readily provides a variety of primary cell types that, to varying degrees, can be expanded and further studied/manipulated in cell culture In addition, PSW-specific molecular markers have been developed that permitted the monitoring of fibroblast, alveolar type II, and vascular endothelial cell types Reconstitution of 3-D cultures of lung tissues with these cell types is now underway This novel system may facilitate the development of rare or disease-specific lung tissue models (eg, to test causes of PSW stranding events and lead to improved treatments for pulmonary hypertension or reperfusion injury in humans) Also, the establishment of a “living” tissue bank biorepository for rare/endangered species could serve multiple purposes as surrogates for freshly isolated samples

Real-time current and wave measurements in ports and harbors using ADCP

Abstract: Both waves and currents rank highly by user groups among oceanographic observation variables. Real-time information of these variables is especially useful for vessel operators and recreational users in and around ports, harbors and bays. Other applications include coastal land management, ecosystem protection and restoration, mitigation of coast hazards and marine accidents, forecast, warning and search and rescue. The U.S. National Ocean Service (NOS) of NOAA maintains and operates a Physical Oceanography Real-Time System (PORTS®) in the Nation's major ports and harbors. Typical hydrological parameters measured include water levels, currents, conductivity, water temperature and depth. Wave information is of interest to PORTS® users, but has only been obtained recently in a few PORTS® sites. However, continued study and laboratory and field testing of various wave measurement instruments and real-time data telemetry technologies have been conducted since 2003. These instruments and technologies include Triaxys Directional Wave buoy, Directional Waverider buoy, and acoustic Doppler current profilers, underwater acoustic modem and links with radio and satellite. Extraction of non-directional wave information from near shore tide gauges (e.g., air acoustic gage and microwave radar altimeter) has also been studied. Among these, acoustic Doppler current profilers (or ADCP) are of particular interest since they are key instrument in PORTS® for current measurements. It is economically and functionally attractive to measure both currents and waves. This paper summarizes the NOS operational system and results of two NOS field studies of real-time ADCP systems for current and wave measurements in ports and harbors. The operational system includes bottom-mounted ADCP with buried cable in the navigation channel. Later, the system was replaced by a U.S. Coast Guard Aid-to-Navigation (ATON) buoy-mounted ADCP with telemetry radio. Shore based Horizontal ADCPs are also being used for real-time current measurement. The two studies (in 2003 and 2008) used different ADCP instruments and data telemetry techniques. The ADCPs used were RDI Workhorse series and AWAC (with internal processor). The underwater acoustic modems used were models UWM1000 and UWM2000H by LinkQuest. The data telemetry technologies used were FreeWave 900MHz spread spectrum line-of-sight radios, and Iridium satellite.

Nutrient Dynamics in Coastal Lagoons and Marine Waters of Vieques, Puerto Rico

Abstract: Determining the efficacy of efforts to conserve natural systems requires that environmental baseline data exist; without such baseline data, it is impossible to determine if management actions are working. This study presents water quality baseline data (nutrients) for the coastal waters of the island of Vieques, Puerto Rico. As the island's economy shifts more towards tourism, these data can be used to verify that conservation efforts to preserve the ecology of the coastal waters are succeeding. Surface waters were sampled at 40 sites, selected using a stratified random sampling design, on 7 occasions between July 2007 and March 2008. Nutrient concentrations were similar to what has been observed in other systems in Puerto Rico, except for in the near coastal lagoons which had significantly higher observed concentrations. Variations in nutrients between lagoons are driven by connectivity to the ocean and lagoon depth. Because of these relationships, and because there are no obvious major sources of point or non-point sources of pollution on the island that would affect only the lagoons, it is hypothesized that these high nutrient levels are the natural status of the system, rather than evidence of eutrophication.

An assessment of the renewable hydrokinetic energy potential in Cook Inlet, Alaska

Abstract: In this article, Rutgers University's Regional Ocean Modeling System (ROMS) was employed with tidal forcing only to carry out a numerical assessment of the spatio-temporal distribution of hydrokinetic energy in Cook Inlet, Alaska by using the power density metric as a proxy. Power density maps showed that the optimal locations for turbine placement were the strait between West and East Foreland and the Anchor Point, North Foreland, Point Possession, northern Fire Island and Knik Arm regions. This assessment will be repeated using a full synoptic hindcast carried out for the June 20-August 20, 2012 time period to simulate realistic conditions. The final assessment from this modeling study will be provided to the Alaska Energy Authority to aid in siting hydrokinetic turbine projects.

Ocean data integration: Successes and lessons learned from the bleeding edge

Abstract: NOAA's Center for Operational Oceanographic Products and Services (CO-OPS), National Data Buoy Center (NDBC) and the U.S. Integrated Ocean Observing System (IOOS®) Program Office have collaborated for several years on a major data integration project to increase interoperability between data providers and the user community. The ultimate goal of the collaboration was to better serve the information needs of researchers, scientists, operational managers, and the public. In this CWP, we provide some background on the motivation and justification for why CO-OPS and NDBC participated in this effort and elaborate on some of the experiences of these two Federal partners during that project. We enumerate a series of general outcomes of the project and identify lessons learned by CO-OPS, NDBC, and the larger IOOS data management community. Finally, we provide suggestions for community wide expansion of select data integration technologies, where they fit in a larger Data Management and Communications (DMAC) architecture and comments on the unique roles of CO-OPS and NDBC as essential elements of the observational and data management infrastructure of the Integrated Ocean Observing System.

Exceedance probability statistics: The likelihood that coastal water levels will reach extreme elevations

Abstract: The Center for Operational Oceanographic Products and Services (CO-OPS) has developed a web-based product (http://tidesandcurrents.noaa.gov/est) to provide online access to exceedance probability statistics at approximately 110 long-term National Water Level Observation Network (NWLON) stations. Each of these stations has at least 30 years of data. The analysis is based on the observed monthly extreme water levels tabulated for the period of record for each station.