Showing papers by "National Ocean Service published in 2014"

From the extreme to the mean: Acceleration and tipping points of coastal inundation from sea level rise

Abstract: Relative sea level rise (RSLR) has driven large increases in annual water level exceedances (duration and frequency) above minor (nuisance level) coastal flooding elevation thresholds established by the National Weather Service (NWS) at U.S. tide gauges over the last half-century. For threshold levels below 0.5 m above high tide, the rates of annual exceedances are accelerating along the U.S. East and Gulf Coasts, primarily from evolution of tidal water level distributions to higher elevations impinging on the flood threshold. These accelerations are quantified in terms of the local RSLR rate and tidal range through multiple regression analysis. Along the U.S. West Coast, annual exceedance rates are linearly increasing, complicated by sharp punctuations in RSLR anomalies during El Nino Southern Oscillation (ENSO) phases, and we account for annual exceedance variability along the U.S. West and East Coasts from ENSO forcing. Projections of annual exceedances above local NWS nuisance levels at U.S. tide gauges are estimated by shifting probability estimates of daily maximum water levels over a contemporary 5-year period following probabilistic RSLR projections of Kopp et al. (2014) for representative concentration pathways (RCP) 2.6, 4.5, and 8.5. We suggest a tipping point for coastal inundation (30 days/per year with a threshold exceedance) based on the evolution of exceedance probabilities. Under forcing associated with the local-median projections of RSLR, the majority of locations surpass the tipping point over the next several decades regardless of specific RCP.

Guidance for implementation of integrated ecosystem assessments: a US perspective

Abstract: Ecosystem-based management (EBM) has emerged as a basic approach for managing human activities in marine ecosystems, with the aim of recovering and conserving marine ecosystems and the services they deliver. Integrated ecosystem assessments (IEAs) further the transition of EBM from principle to practice by providing an efficient, transparent means of summarizing the status of ecosystem components, screening and prioritizing potential risks, and evaluating alternative management strategies against a backdrop of environmental variability. In this paper, we draw upon lessons learned from the US National Oceanic and Atmospheric Administration’s IEA programme to outline steps required for IEA implementation. We provide an overview of the conceptual framework for IEAs, the practical constraints that shape the structure of individual IEAs, and the uses and outcomes of IEAs in support of EBM.

Boundary influences on HAB phytoplankton ecology in a stratification-enhanced upwelling shadow

Abstract: Coastal marine ecosystems are profoundly influenced by processes that originate from their boundaries. These include fluid boundaries—with the atmosphere, oceanic boundary currents and terrestrial aquatic systems, as well as solid boundaries—with the seafloor and coast. Phytoplankton populations transfer complexly interacting boundary influences into the biosphere. In this contribution, we apply data from an ocean observing and modeling system to examine boundary influences driving phytoplankton ecology in Monterey Bay, CA, USA. The study was focused on species that may cause harmful algal blooms (HABs). During September–October 2010, autonomous molecular analytical devices were moored at two locations characterized by different degrees of stratification and exposure to upwelling dynamics. The time-series revealed multiple transitions in local HAB phytoplankton communities, involving diatoms (Pseudo-nitzschia spp.), dinoflagellates (Alexandrium catenella), and raphidophytes (Heterosigma akashiwo). Observational and model results showed that the biological transitions were closely related to environmental changes that resulted from a variety of boundary processes—responses of oceanic circulation to wind forcing, influxes of different water types that originated outside the bay, and emergence of strongly stratified nearshore water into the greater bay. Boundary processes were further implicated at patch scales. High-resolution mapping and sampling of a phytoplankton-enriched patch were conducted in a Lagrangian framework using autonomous underwater vehicles. These highly resolved measurements showed that small-scale spatial patterns in the toxicity of Pseudo-nitzschia populations were related to the coupling of resuspended sediments from the bottom boundary layer to the surface mixed layer.

Domoic acid epileptic disease.

Abstract: Domoic acid epileptic disease is characterized by spontaneous recurrent seizures weeks to months after domoic acid exposure. The potential for this disease was first recognized in a human case study of temporal lobe epilepsy after the 1987 amnesic shellfish-poisoning event in Quebec, and was characterized as a chronic epileptic syndrome in California sea lions through investigation of a series of domoic acid poisoning cases between 1998 and 2006. The sea lion study provided a breadth of insight into clinical presentations, unusual behaviors, brain pathology, and epidemiology. A rat model that replicates key observations of the chronic epileptic syndrome in sea lions has been applied to identify the progression of the epileptic disease state, its relationship to behavioral manifestations, and to define the neural systems involved in these behavioral disorders. Here, we present the concept of domoic acid epileptic disease as a delayed manifestation of domoic acid poisoning and review the state of knowledge for this disease state in affected humans and sea lions. We discuss causative mechanisms and neural underpinnings of disease maturation revealed by the rat model to present the concept for olfactory origin of an epileptic disease; triggered in dendodendritic synapases of the olfactory bulb and maturing in the olfactory cortex. We conclude with updated information on populations at risk, medical diagnosis, treatment, and prognosis.

In situ tagging technique for fishes provides insight into growth and movement of invasive lionfish

Abstract: Information on fish movement and growth is primarily obtained through the marking and tracking of individuals with external tags, which are usually affixed to anesthetized individuals at the surface. However, the quantity and quality of data obtained by this method is often limited by small sample sizes owing to the time associated with the tagging process, high rates of tagging-related mortality, and displacement of tagged individuals from the initial capture location. To address these issues, we describe a technique for applying external streamer and dart tags in situ, which uses SCUBA divers to capture and tag individual fish on the sea floor without the use of anesthetic. We demonstrate this method for Indo-Pacific lionfish (Pterois volitans/P. miles), species which are particularly vulnerable to barotrauma when transported to and handled at the surface. To test our method, we tagged 161 individuals inhabiting 26 coral reef locations in the Bahamas over a period of 3 years. Our method resulted in no instances of barotrauma, reduced handling and recovery time, and minimal post-tagging release displacement compared with conventional ex situ tag application. Opportunistic resighting and recapture of tagged individuals reveals that lionfish exhibit highly variable site fidelity, movement patterns, and growth rates on invaded coral reef habitats. In total, 24% of lionfish were resighted between 29 and 188 days after tagging. Of these, 90% were located at the site of capture, while the remaining individuals were resighted between 200 m and 1.1 km from initial site of capture over 29 days later. In situ growth rates ranged between 0.1 and 0.6 mm/day. While individuals tagged with streamer tags posted slower growth rates with increasing size, as expected, there was no relationship between growth rate and fish size for individuals marked with dart tags, potentially because of large effects of tag presence on the activities of small bodied lionfish (i.e., <150 mm), where the tag was up to 7.6% of the lionfish's mass. Our study offers a novel in situ tagging technique that can be used to provide critical information on fish site fidelity, movement patterns, and growth in cases where ex situ tagging is not feasible.

Bottom side‐roll feeding by humpback whales (Megaptera novaeangliae) in the southern Gulf of Maine, U.S.A

Abstract: Humpback whales (Megaptera novaeangliae) are known for the variety and complexity of their feeding behaviors. Here we report on the use of synchronous motion and acoustic recording tags (DTAGs) to provide the first detailed kinematic descriptions of humpback whales using bottom side-rolls (BSRs) to feed along the seafloor. We recorded 3,505 events from 19 animals (individual range 8–722). By animal, mean BSR duration ranged from 14.1 s to 36.2 s.; mean body roll angle from 80o to 121o, and mean pitch from 7o to 38o. The median interval between sequential BSRs, by animal, ranged from 24.0 s to 63.6 s and animals tended to maintain a consistent BSR heading during long BSR series encompassing multiple dives. BSRs were most frequent between 2200 and 0400. We identify three classes of behavior: simple side-roll, side-roll inversion, and repetitive scooping. Results indicate that BSR feeding is a common technique in the study area and there is both coordination and noncoordination between animals. We argue that this behavior is not lunge feeding as normally characterized, because animals are moving slowly through the event. The behavior also leads to vulnerability to entanglement in bottom-set fishing gear, a major mortality factor for the species.

Ocean Circulation and Water Mass Characteristics around the Galápagos Archipelago Simulated by a Multiscale Nested Ocean Circulation Model

Abstract: Ocean circulation and water mass characteristics around the Galapagos Archipelago are studied using a four-level nested-domain ocean system (HYCOM). The model sensitivity to atmospheric forcing frequency and spatial resolution is examined. Results show, that with prescribed atmospheric forcing, HYCOM can generally simulate the major El Nino events especially the strong 1997-1998 events. Waters surrounding the archipelago show a large range of temperature and salinity in association with four different current systems. West zones of Isabella and Fernandina Islands are the largest upwelling zones, resulting from the collision of the Equatorial Undercurrent (EUC) with the islands, bringing relatively colder, salty waters to the surface and marking the location of the highest biological production. Model results, which agree well with observations, show a seasonal cycle in the transport of the EUC, reaching a maximum during the late spring/early summer and minimum in the late fall. The far northern region is characterized by warmer, fresher water with the greatest mixed layer depth as a result of Panama Current waters entering from the northeast. Water masses over the remainder of the region result from mixing of cool Peru Current waters and upwelled Cold Tongue waters entering from the east.

Impact of Hurricane Irene on Vibrio vulnificus and Vibrio parahaemolyticus concentrations in surface water, sediment, and cultured oysters in the Chesapeake Bay, MD, USA

Abstract: To determine if a storm event (ie, high winds, large volumes of precipitation) could alter concentrations of Vibrio vulnificus and Vibrio 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 03 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 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 change 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=041, p=004), and V vulnificus in sediment was correlated with secchi depth (r=-093, p< 001), salinity (r=-046, p=002), tidal height (r=-045, p=003), and surface water V vulnificus (r=098, p< 001) 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=-048, p=002[sediment]; r=-097 p< 001[surface water]) and tidal height (r=-096 p< 001[sediment], r=-059,p< 001 [surface water]) The concentrations of Vibrio spp were higher in oysters relative to other studies (average V vulnificus 4x105 MPN g-1, V parahaemolyticus 1x105 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 w

Enhancing Shellfish Safety in Alaska through Monitoring of Harmful Algae and Their Toxins

Abstract: Harmful algal blooms cause serious problems to public health and the economic viability of shellfish industries in Alaska. The most common phycotoxins in this region are saxitoxin and its congeners, collectively referred to as paralytic shellfish toxins, the causative agents of paralytic shellfish poisoning (PSP) in humans. The illness of 26 and death of 2 people in southeast Alaska as a result of PSP in 2010 through 2012 illustrates the need for change in the way paralytic shellfish toxins are monitored and managed in Alaska. The implementation of a scientific monitoring partnership, the Alaska Harmful Algal Bloom monitoring network, designed to provide an early warning of harmful algal blooms—in particular, those that cause PSP—is described. The program includes a tiered sampling approach, and weekly microscopic observation of seawater samples for the presence of the causative toxic dinoflagellate Alexandrium, followed by rapid toxin testing using a high-throughput antibody-based test as a comp...

Integrating multiple techniques to identify stock boundaries of common bottlenose dolphins (Tursiops truncatus)

Abstract: Under US policy, a stock is a group of animals shown to be demographically independent from other such groups. Evidence of demographic delineations for marine mammal stocks is gained primarily through genetic analysis. However, additional techniques play an important role in determining fine-scale ranging patterns that can be used to define a stock's geographic boundaries. In cases where genetic studies have not yet been performed, movement and ranging pattern data are essential in identifying a targeted geographic region for tissue sampling and genetic studies. Photo-identification surveys, vessel-based radio telemetry, automated radio telemetry systems (ARTS), and satellite-linked telemetry are sampling techniques that have been used to determine common bottlenose dolphin ranging patterns and provide detailed insight into stock boundaries. The results of near simultaneous use of these sampling techniques are compared using data from a case study of bottlenose dolphins within the estuaries of southern Georgia. Satellite-linked and radio telemetry were determined to be useful sampling techniques for identification of short-term ranging patterns. Satellite-linked telemetry had the second lowest cost per location ($122) and identified dolphin ranging patterns within and outside of the study area boundaries. Vessel-based radio telemetry was more costly ($195 per location) and had relatively limited tracking coverage. However, this sampling technique permitted visual observations of animal and tag condition. The combination of vessel-based radio telemetry and ARTS, which had the lowest cost per location ($34), was an effective method for determining ranging patterns of tagged individuals within and outside of the study area. Photo-identification surveys, relative to satellite-linked and radio telemetry, were not as efficient for determination of targeted individuals’ short-term ranging patterns and had the highest cost per location of the four sampling techniques ($292). However, photo-identification is more effective than any other technique for compiling data on large numbers of individuals within a designated study area. Photo-identification surveys are essential for long-term monitoring and provide additional insight into dolphin stock structure that cannot be determined through telemetry alone. Copyright © 2013 John Wiley & Sons, Ltd.

Improving the Display of Wind Patterns and Ocean Currents

Abstract: Considerable effort has gone into building numerical weather and ocean prediction models during the past 50 years. Less effort has gone into the visual representation of output from those forecast models and many of the techniques used are known to be ineffective. The effectiveness of a data display depends on how well critical patterns can be perceived. This paper outlines a set of perceptual principles for what makes a good representation of a 2D vector field and shows how these principles can be used for the portrayal of currents, winds, and waves. Examples are given from a series of evaluation studies that examine the optimal representation of these variables. The results suggest that for static graphic presentations, equally spaced streamlines may be optimal. If wind barbs are curved to follow streamlines, perception of local wind speed and direction as well as the overall pattern is improved. For animated portrayals of model output, animated streamlets can perceptually separate layers of information...

Comparative toxicity of pyrethroid insecticides to two estuarine crustacean species, Americamysis bahia and Palaemonetes pugio

Abstract: Pyrethroid insecticides are widely used on agricultural crops, as well as for nurseries, golf courses, urban structural and landscaping sites, residential home and garden pest control, and mosquito abatement Evaluation of sensitive marine and estuarine species is essential for the development of toxicity testing and risk-assessment protocols Two estuarine crustacean species, Americamysis bahia (mysids) and Palaemonetes pugio (grass shrimp), were tested with the commonly used pyrethroid compounds, lambda-cyhalothrin, permethrin, cypermethrin, deltamethrin, and phenothrin Sensitivities of adult and larval grass shrimp and 7-day-old mysids were compared using standard 96-h LC50 bioassay protocols Adult and larval grass shrimp were more sensitive than the mysids to all the pyrethroids tested Larval grass shrimp were approximately 18-fold more sensitive to lambda-cyhalothrin than the mysids Larval grass shrimp were similar in sensitivity to adult grass shrimp for cypermethrin, deltamethrin, and phenothrin, but larvae were approximately twice as sensitive to lambda-cyhalothrin and permethrin as adult shrimp Acute toxicity to estuarine crustaceans occurred at low nanogram per liter concentrations of some pyrethroids, illustrating the need for careful regulation of the use of pyrethroid compounds in the coastal zone © 2013 Wiley Periodicals, Inc Environ Toxicol 29: 1099–1106, 2014

Development of a real-time PCR for the detection of pathogenic Leptospira spp. in California sea lions

Abstract: Several real-time PCR assays are currently used for detection of pathogenic Leptospira spp.; however, few methods have been described for the successful evaluation of clinical urine samples. This study reports a rapid assay for the detection of pathogenic Leptospira spp. in California sea lions Zalophus californianus using real-time PCR with primers and a probe targeting the lipL32 gene. The PCR assay had high analytic sensitivity-the limit of detection was 3 genome copies per PCR volume using L. interrogans serovar Pomona DNA and 100% analytic specificity; it detected all pathogenic leptospiral serovars tested and none of the non-pathogenic Leptospira species (L. biflexa and L. meyeri serovar Semaranga), the intermediate species L. inadai, or the non-Leptospira pathogens tested. Our assay had an amplification efficiency of 1.00. Comparisons between the real-time PCR assay and culture isolation for detection of pathogenic Leptospira spp. in urine and kidney tissue samples from California sea lions showed that samples were more often positive by real-time PCR than by culture methods. Inclusion of an internal amplification control in the real-time PCR assay showed no inhibitory effects in PCR negative samples. These studies indicated that our real-time PCR assay has high analytic sensitivity and specificity for the rapid detection of pathogenic Leptospira species in urine and kidney tissue samples.

Distribution and sources of PCBs (Aroclor 1268) in the Sapelo Island National Estuarine Research Reserve

Abstract: Aroclor 1268 is a highly chlorinated PCB mixture that was released into the aquatic environment near Brunswick, GA (BR), as a result of decades of local industrial activity. This extensive contamination has led to US EPA Superfund designation in estuarine areas in and around Purvis Creek, GA. Roughly 50 km to the northeast is the Sapelo Island National Estuarine Research Reserve (SI) where previous studies have documented unexpectedly high Aroclor 1268-like PCB levels in blubber and plasma samples of resident bottlenose dolphins. This result led to a collaborative effort to assess the PCB patterns and concentrations in SI sediment and fish (as potential vectors for PCB transfer to SI resident dolphins). Thirty SI randomly assigned stations were sampled for sediment PCB levels. Additionally, fish were collected and analyzed from SI (n = 31) and BR (n = 33). Results were pooled with regional assessments of PCB concentrations from South Carolina and North Carolina in an effort to determine the association of Aroclor 1268 levels in SI samples. Results indicated that PCB levels in sediment and fish are much lower in the SI estuary compared to BR sediment and fish concentrations. However, PCB congener profiles for both sediments and fish were similar between the two locations and consistent with the Aroclor 1268 signature, indicating possible transport from the Brunswick area. A likely source of Aroclor 1268 in dolphins from SI is contaminated fish prey.

Using Procedural Blanks to Generate Analyte-Specific Limits of Detection for Persistent Organic Pollutants Based on GC-MS Analysis

Abstract: Several methods are used to generate a limit of detection for organic pollutants measured by gas chromatography–mass spectroscopy (GC-MS); all have theoretical and practical drawbacks. The current project investigated two common existing methods (statistical and empirical) for applicability to chromatographic properties from real samples, comparing these with a new proposed method using procedural blanks to estimate a minimum detectable peak area. Weaknesses of all three methods are discussed. The proposed method was superior to other examined methods in that it provided analyte-specific limits of detection linked to the recovery of mass-labeled internal standards for every analyte within every sample. Other identified quality assurance benefits included the following: enhanced protection against false positives; providing a sensitivity performance metric across batch, analyst, and instrument; enabling chemists with discretionary decisions specific to every analyte regarding detectability and interference...

Limited gene flow in Uca minax (LeConte 1855) along a tidally influenced river system

Abstract: For crab larvae, swimming behaviors coupled with the movement of tides suggests that larvae can normally move upstream within estuaries by avoiding ebb tides and actively swimming during flood tides (i.e., flood-tide transport [FTT]). Recently, a 1-D transport model incorporating larval behavior predicted that opposing forces of river discharge and tidal amplitude in the Pee Dee River/Winyah Bay system of South Carolina, USA, could limit dispersal within a single estuary for downstream transport as well as become a dispersal barrier to recruitment of late stage larvae to the freshwater adult habitats of Uca minax (LeConte 1855). We sequenced 394-bp of the mitochondrial cytochrome apoenzyme b for 226 adult U. minax, from four locales along a 49-km stretch of the Pee Dee River/Winyah Bay estuary, above and below the boundary of salt intrusion. Results of an analysis of molecular variance (AMOVA) and an exact test of population differentiation showed a small, but statistically significant (α=0.05) population subdivision among adults of the 4 subpopulations, as well as all subpopulations being significantly differentiated (α=0.05). This pattern fitted with model predictions, which implies that larval transport within the tidally influenced river system is limited.

Augmenting Anti-Cancer Natural Products with a Small Molecule Adjuvant

Abstract: Aquatic microbes produce diverse secondary metabolites with interesting biological activities. Cytotoxic metabolites have the potential to become lead compounds or drugs for cancer treatment. Many cytotoxic compounds, however, show undesirable toxicity at higher concentrations. Such undesirable activity may be reduced or eliminated by using lower doses of the cytotoxic compound in combination with another compound that modulates its activity. Here, we have examined the cytotoxicity of four microbial metabolites [ethyl N-(2-phenethyl) carbamate (NP-1), Euglenophycin, Anabaenopeptin, and Glycolipid 652] using three in vitro cell lines [human breast cancer cells (MCF-7), mouse neuroblastoma cells (N2a), and rat pituitary epithelial cells (GH4C1)]. The compounds showed variable cytotoxicity, with Euglenophycin displaying specificity for N2a cells. We have also examined the modulatory power of NP-1 on the cytotoxicity of the other three compounds and found that at a permissible concentration (125 µg/mL), NP-1 sensitized N2a and MCF-7 cells to Euglenophycin and Glycolipid 652 induced cytotoxicity.

Tissue distribution of amino acid- and lipid-brevetoxins after intravenous administration to C57BL/6 mice.

Abstract: Brevetoxins produced during algal blooms of the dinoflagellate Karenia are metabolized by shellfish into reduction, oxidation, and conjugation products. Brevetoxin metabolites comprising amino acid- and lipid conjugates account for a large proportion of the toxicity associated with the consumption of toxic shellfish. However, the disposition of these brevetoxin metabolites has not been established. Using intravenous exposure to C57BL/6 mice, we investigated the disposition in the body of three radiolabeled brevetoxin metabolites. Amino acid–brevetoxin conjugates represented by S-desoxy-BTX-B2 (cysteine-BTX-B) and lipid–brevetoxin conjugates represented by N-palmitoyl-S-desoxy-BTX-B2 were compared to dihydro-BTX-B. Tissue concentration profiles were unique to each of the brevetoxin metabolites tested, with dihydro-BTX-B being widely distributed to all tissues, S-desoxy-BTX-B2 concentrated in kidney, and N-palmitoyl-S-desoxy-BTX-B2 having the highest concentrations in spleen, liver, and lung. Elimination pa...