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Sample records for quaranfil johnston atoll

  1. Quaranfil, Johnston Atoll, and Lake Chad viruses are novel members of the family Orthomyxoviridae.

    PubMed

    Presti, Rachel M; Zhao, Guoyan; Beatty, Wandy L; Mihindukulasuriya, Kathie A; da Rosa, Amelia P A Travassos; Popov, Vsevolod L; Tesh, Robert B; Virgin, Herbert W; Wang, David

    2009-11-01

    Arboviral infections are an important cause of emerging infections due to the movements of humans, animals, and hematophagous arthropods. Quaranfil virus (QRFV) is an unclassified arbovirus originally isolated from children with mild febrile illness in Quaranfil, Egypt, in 1953. It has subsequently been isolated in multiple geographic areas from ticks and birds. We used high-throughput sequencing to classify QRFV as a novel orthomyxovirus. The genome of this virus is comprised of multiple RNA segments; five were completely sequenced. Proteins with limited amino acid similarity to conserved domains in polymerase (PA, PB1, and PB2) and hemagglutinin (HA) genes from known orthomyxoviruses were predicted to be present in four of the segments. The fifth sequenced segment shared no detectable similarity to any protein and is of uncertain function. The end-terminal sequences of QRFV are conserved between segments and are different from those of the known orthomyxovirus genera. QRFV is known to cross-react serologically with two other unclassified viruses, Johnston Atoll virus (JAV) and Lake Chad virus (LKCV). The complete open reading frames of PB1 and HA were sequenced for JAV, while a fragment of PB1 of LKCV was identified by mass sequencing. QRFV and JAV PB1 and HA shared 80% and 70% amino acid identity to each other, respectively; the LKCV PB1 fragment shared 83% amino acid identity with the corresponding region of QRFV PB1. Based on phylogenetic analyses, virion ultrastructural features, and the unique end-terminal sequences identified, we propose that QRFV, JAV, and LKCV comprise a novel genus of the family Orthomyxoviridae.

  2. Quaranfil, Johnston Atoll, and Lake Chad Viruses Are Novel Members of the Family Orthomyxoviridae▿

    PubMed Central

    Presti, Rachel M.; Zhao, Guoyan; Beatty, Wandy L.; Mihindukulasuriya, Kathie A.; Travassos da Rosa, Amelia P. A.; Popov, Vsevolod L.; Tesh, Robert B.; Virgin, Herbert W.; Wang, David

    2009-01-01

    Arboviral infections are an important cause of emerging infections due to the movements of humans, animals, and hematophagous arthropods. Quaranfil virus (QRFV) is an unclassified arbovirus originally isolated from children with mild febrile illness in Quaranfil, Egypt, in 1953. It has subsequently been isolated in multiple geographic areas from ticks and birds. We used high-throughput sequencing to classify QRFV as a novel orthomyxovirus. The genome of this virus is comprised of multiple RNA segments; five were completely sequenced. Proteins with limited amino acid similarity to conserved domains in polymerase (PA, PB1, and PB2) and hemagglutinin (HA) genes from known orthomyxoviruses were predicted to be present in four of the segments. The fifth sequenced segment shared no detectable similarity to any protein and is of uncertain function. The end-terminal sequences of QRFV are conserved between segments and are different from those of the known orthomyxovirus genera. QRFV is known to cross-react serologically with two other unclassified viruses, Johnston Atoll virus (JAV) and Lake Chad virus (LKCV). The complete open reading frames of PB1 and HA were sequenced for JAV, while a fragment of PB1 of LKCV was identified by mass sequencing. QRFV and JAV PB1 and HA shared 80% and 70% amino acid identity to each other, respectively; the LKCV PB1 fragment shared 83% amino acid identity with the corresponding region of QRFV PB1. Based on phylogenetic analyses, virion ultrastructural features, and the unique end-terminal sequences identified, we propose that QRFV, JAV, and LKCV comprise a novel genus of the family Orthomyxoviridae. PMID:19726499

  3. Johnston Atoll Chemical Agent Disposal System (JACADS)

    SciTech Connect

    Not Available

    1990-06-01

    This Final Second Supplemental Environmental Impact Statement (SSEIS) to the Johnston Atoll Chemical Agent Disposal System (JACADS) Environmental Impact Statement (EIS) assesses the effects of receiving, storing, and ultimately destructing the United States stockpile of lethal unitary chemical munitions currently stored in the Federal Republic of Germany (FRG) (European stockpile) at the Army's JACADS facility located on Johnston Atoll in the Pacific Ocean. This Final SSEIS addresses the effects of the following proposed European stockpile activities: the transport of the European stockpile from the territorial limit to Johnston Island, the unloading of munitions from transportation ships, the on-island munitions transport and handling, on-island munitions storage, the disposal of munitions in the JACADS facility, the disposal of incineration wastes, and alternatives to the proposed action. This document also updates information in the 1983 EIS and the 1988 SEIS, as appropriate. 46 refs., 10 figs., 9 tabs.

  4. Clean soil at Eniwetok and Johnston Atolls

    SciTech Connect

    Bramlitt, E.T.

    1990-01-01

    The Defense Nuclear Agency has managed two large-scale soil cleanups (landmass decontaminations) of plutonium contamination. Both are at Pacific Ocean atolls formerly used for nuclear weapons tests. The Eniwetok Atoll (EA) cleanup between 1977 and 1980 evaluated 390 ha of contaminated land and cleaned 50 ha by removing 80,000 m[sup 3] of contaminated soil. The Johnston Atoll (JA) cleanup is in process. It has checked 270 ha, will clean 15 ha, and plans for removal of 80,000 m[sup 3] of soil. The cleanups are similar in other respects including carbonate-based soil, in situ radiation surveys, contamination characteristics, soil excavation methods, safety, and weather. The two cleanups are in contrast relative to planning time, agencies involved, funding, documentation, environmental considerations, cleanup workforce, site beneficiaries, waste characterization, regulatory permits, management, and project duration. The most noteworthy differences are the rationale for cleanup, the cleanup process, the definition of clean, and the cost.

  5. Stabilization of lead-contaminated municipal ash on Johnston Atoll

    SciTech Connect

    Lear, P.R.; Gemar, D.; Ingoglia, M.

    1995-12-31

    Johnston Atoll is located approximately 700 nautical miles southwest of the Hawaiian Islands. Johnston Atoll is an unincorporated territory of the United States with operational control administered by the Defense Nuclear Agency (DNA). The atoll serves as a storage and destruction site for chemical munitions under the Johnston Atoll Chemical Agent Disposal System (JACADS). Previously, the atoll served as a site high and low altitude nuclear testing and more recently, principal overseas base to support the Nation Nuclear Readiness Program`s Safeguard C, which required the capability to promptly resume nuclear testing. Johnston Atoll is also managed by the US Fish and Wildlife Service as a National Wildlife Refuge. The atoll is comprised of four small islands, Johnston, Sand, North and East, surrounded by a coral reef. Most activities at the atoll are limited to Johnston Island (JI). The Solid Waste Burn Pit (SWBP) is located on the northwest end of JI, approximately 50 feet from the lagoon. Constructed in 1978 or shortly thereafter, the SWBP was utilized to burn refuse generated during the daily operation of the island. Part of the SWBP remains active and is still in use, burning nonhazardous waste material. In the inactive portion of the SWBP, hazardous materials such as batteries, paints, and solvents were burned in the past. This paper addresses the remediation of the inactive portion of the SWBP only.

  6. Processing plutonium-contaminated soil on Johnston Atoll

    SciTech Connect

    Moroney, K.; Moroney, J. III; Turney, J.

    1994-07-01

    This article describes a cleanup project to process plutonium- and americium-contaminated soil on Johnston Atoll for volume reduction. Thermo Analytical`s (TMA`s) segmented gate system (SGS) for this remedial operation has been in successful on-site operation since 1992. Topics covered include the basis for development, a description of the Johnston Atoll; the significance of results; the benefits of the technology; applicability to other radiologically contaminated sites. 7 figs., 1 tab.

  7. Structural failure and drowning of Johnston Atoll, central Pacific Basin

    NASA Astrophysics Data System (ADS)

    Keating, Barbara H.

    Emery (1956) and Ashmore (1973) described the geology of Johnston Atoll (Northern Line Islands chain) and pointed out the anomalous structure of the atoll. These studies led Ashmore )1973) to suggest that the atoll itself is tilted. Johnston Atoll appears to be an example of a seamount that is undergoing a transition from an atoll to a drowned seamount (guyot). Submersible studies of the shallow carbonate bank demonstrate that the carbonate bank displays important karstic features. Recent side-scan sonar studies of the southern flank of this seamount provide evidence that the southern flank of the seamount has undergone substantial mass-wasting. We hypothesize that the mass-wasting of the seamount has loaded the seafloor surrounding Johnston Island unevenly. The southeast Johnston Basin lies 700 m shallower than the southwest Johnston Basin. The loading of the southeast Johnston Basin has resulted in differential subsidence of the sea floor surrounding the seamount which has resulted in the tilting of the seamount (0.016°) and is responsible for the drowning of much of the reef. It is suggested that local structural failure, preferential erosion and drainage, and differential subsidence of seamounts can cause drowning of reefs which may lead to the formation of guyots.

  8. Colonization of the Hawaiian Archipelago via Johnston Atoll: a characterization of oceanographic transport corridors for pelagic larvae using computer simulation

    NASA Astrophysics Data System (ADS)

    Kobayashi, Donald R.

    2006-08-01

    Larval transport between Johnston Atoll and the Hawaiian Archipelago was examined using computer simulation and high-resolution ocean current data. The effects of pelagic larval duration and spawning seasonality on long-distance transport and local retention were examined using a Lagrangian, individual-based approach. Retention around Johnston Atoll appeared to be low, and there appeared to be seasonal effects on both retention and dispersal. Potential larval transport corridors between Johnston Atoll and the Hawaiian Archipelago were charted. One corridor connects Johnston Atoll with the middle portion of the Hawaiian Archipelago in the vicinity of French Frigate Shoals. Another corridor connects Johnston Atoll with the lower inhabited islands in the vicinity of Kauai. Transport appears to be related to the subtropical countercurrent and the Hawaiian Lee countercurrent, both located to the west of the archipelago and flowing to the east. A new analytical tool, termed CONREC-IRC is presented for the quantification of spatial patterns.

  9. Johnston Atoll Chemical Agent Disposal System (JACADS) Final Second Supplemental Environmental Impact Statement (SSEIS)

    SciTech Connect

    Not Available

    1990-06-01

    This Final Second Supplemental Environmental Impact Statement (SSEIS) to the Johnston Atoll Chemical Agent Disposal System (JACADS) Environmental Impact Statement (EIS) assesses the effects of receiving, storing, and ultimately destructing the United States stockpile of lethal unitary chemical munitions currently stored in the Federal Republic of Germany (FRG) (European stockpile) at the Army's JACADS facility located on Johnston Atoll in the Pacific Ocean. This Final SSEIS addresses the effects of the following proposed European stockpile activities: the transport of the European stockpile from the territorial limit to Johnston Island, the unloading of munitions from transportation ships, the on-island munitions transport and handling, on-island munitions storage, the disposal of munitions in the JACADS facility, the disposal of incineration wastes, and alternatives to the proposed action. This document also updates information in the 1983 EIS and the 1988 SEIS, as appropriate. This volume contains reproduced letters from various agencies, reproduced written comments received from the public, and a transcript from the public meeting.

  10. Radiological survey of Johnston Atoll. Dates of survey: April-August 1980. Revision 1

    SciTech Connect

    Jaffe, R.J.; Tipton, W.J.

    1982-04-01

    A radiological survey was conducted over all land areas of Johnston Atoll between April and August 1980. The survey was performed to locate and quantify residual surface transuranic (i.e., plutonium and americium) contamination resulting from three THOR missile aborts which occurred during that portion of the 1962 atmospheric nuclear testing series conducted by the United States from Johnston Island. A high purity germanium planar detector was utilized to enhance the detection sensitivity for the 59.5 keV gamma ray from /sup 241/Am. Results are reported as equivalent surface concentration in units of nCi/m/sup 2/. Conversion factors are also included for several other assumed source distributions. Soil samples were obtained to determine plutonium-to-americium ratios. 7 references, 14 figures, 1 table.

  11. Remediation of transuranic-contaminated coral soil at Johnston Atoll using the segmented gate system

    SciTech Connect

    Bramlitt, E.; Johnson, N.

    1994-12-31

    Thermo Analytical, Inc. (TMA) has developed a system to remove clean soil from contaminated soil. The system consists of a soil conveyor, an array of radiation detectors toward the conveyor feed end, a gate assembly at the conveyor discharge end, and two additional conveyors which move discharged soil to one or another paths. The gate assembly is as wide as the ``sorter conveyor,`` and it has eight individual gates or segments. The segments automatically open or close depending on the amount of radioactivity present. In one position they pass soil to a clean soil conveyor, and in the other position they let soil fall to a hot soil conveyor. The soil sorting process recovers clean soil for beneficial use and it substantially reduces the quantity of soil which must be decontaminated or prepared for waste disposal. The Segmented Gate System (SGS) was developed for the cleanup of soil contaminated with some transuranium elements at Johnston Atoll. It has proven to be an effective means for recovering clean soil and verifying that soil is clean, minimizing the quantity of truly contaminated soil, and providing measures of contamination for waste transport and disposal. TMA is constructing a small, transportable soil cleanup as it is confident the SGS technology can be adapted to soils and contaminants other than those at Johnston Atoll. It will use this transportable plant to demonstrate the technology and to develop site specific parameters for use in designing plants to meet cleanup needs.

  12. Weights, hematology and serum chemistry of free-ranging brown boobies (Sula leucogaster) in Johnston Atoll, Central Pacific

    USGS Publications Warehouse

    Work, T.M.

    1999-01-01

    Hematologic and serum chemistry values are reported for 105 brown boobies (Sula leucogaster) from Johnston Atoll, Central Pacific. Hematocrit, estimated total plasma solids, total and differential white cell counts, serum glucose, calcium, phosphorus, uric acid, total protein, albumin, globulin, aspartate aminotransferase, and creatinine phosphokinase were analyzed. Hematologic and serum chemistry values varied with age and sex. Values were compared with those of red-footed boobies and other tropical and temperate marine pelecaniforms.

  13. Weights, hematology and serum chemistry of free-ranging brown boobies (Sula leucogaster) in Johnston Atoll, Central Pacific

    USGS Publications Warehouse

    Work, Thierry M.

    1999-01-01

    Hematologic and serum chemistry values are reported for 105 brown boobies (Sula leucogaster) from Johnston Atoll, Central Pacific. Hematocrit, estimated total plasma solids, total and differential white cell counts, serum glucose, calcium, phosphorus, uric acid, total protein, albumin, globulin, aspartate aminotransferase, and creatinine phosphokinase were analyzed. Hematologic and serum chemistry values varied with age and sex. Values were compared with those of red-footed boobies and other tropical and temperate marine pelecaniforms.

  14. Independent verification of plutonium decontamination on Johnston Atoll (1992--1996)

    SciTech Connect

    Wilson-Nichols, M.J.; Wilson, J.E.; McDowell-Boyer, L.M.; Davidson, J.R.; Egidi, P.V.; Coleman, R.L.

    1998-05-01

    The Field Command, Defense Special Weapons Agency (FCDSWA) (formerly FCDNA) contracted Oak Ridge National Laboratory (ORNL) Environmental Technology Section (ETS) to conduct an independent verification (IV) of the Johnston Atoll (JA) Plutonium Decontamination Project by an interagency agreement with the US Department of Energy in 1992. The main island is contaminated with the transuranic elements plutonium and americium, and soil decontamination activities have been ongoing since 1984. FCDSWA has selected a remedy that employs a system of sorting contaminated particles from the coral/soil matrix, allowing uncontaminated soil to be reused. The objective of IV is to evaluate the effectiveness of remedial action. The IV contractor`s task is to determine whether the remedial action contractor has effectively reduced contamination to levels within established criteria and whether the supporting documentation describing the remedial action is adequate. ORNL conducted four interrelated tasks from 1992 through 1996 to accomplish the IV mission. This document is a compilation and summary of those activities, in addition to a comprehensive review of the history of the project.

  15. [Taxonomic status of the Tyulek virus (TLKV) (Orthomyxoviridae, Quaranjavirus, Quaranfil group) isolated from the ticks Argas vulgaris Filippova, 1961 (Argasidae) from the birds burrow nest biotopes in the Kyrgyzstan].

    PubMed

    L'vov, D K; Al'khovskiĭ, S V; Shchelkanov, M Iu; Shchetinin, A M; Deriabin, P G; Aristova, V A; Gitel'man, A K; Samokhvalov, E I; Botikov, A G

    2014-01-01

    The Tyulek virus (TLKV) was isolated from the ticks Argas vulgaris Filippova, 1961 (Argasidae), collected from the burrow biotopes in multispecies birds colony in the Aksu river floodplain near Tyulek village (northern part of Chu Valley, Kyrgyzstan). Recently, the TLKV was assigned to the Quaranfil group (including the Quaranfil virus (QRFV), Johnston Atoll virus (JAV), Lake Chad virus) that is a novel genus of the Quaranjavirus in the Orthomyxoviridae family. In his work, the complete genome (ID GenBank KJ438647-8) sequence of the TLKV was determined using next-generation sequencing (Illumina platform). Comparison of deduced amino acid sequences shows closed relationship of the TLKV with QRFV and JAV (86% and 84% identity for PB1 and about 70% for PB2 and PA, respectively). The identity level of the TLKV and QRFV in outer glycoprotein GP is 72% and 80% for nucleotide and amino acid sequences, respectively. The phylogenetic analysis showed that the TLKV belongs to the genus of the Quaranjavirus in the family Orthomyxoviridae.

  16. Monitored plutonium aerosols at a soil cleanup site on Johnston Atoll

    SciTech Connect

    Shinn, J.H.; Fry, C.O.; Johnson, J.S.

    1996-01-23

    Suspended plutonium in air was monitored for four periods near the operation of a stationary sorting system used to {open_quotes}mine{close_quotes} contaminated soil on Johnston Atoll. The monitoring periods were 14 October-14 November 1992, 20 October-15 November 1993, 16 August-3 November 1994, and 17 February-27 February 1995. Pairs of high volume air samplers were located at each of four locations of the process stream: the {open_quotes}spoils pile{close_quotes} that was the feedstock, the {open_quotes}plant area{close_quotes} near the hot soil gate of the sorter, the {open_quotes}clean pile{close_quotes} conveyer area where sorted clean soil was moved, and the {open_quotes}oversize soil{close_quotes} crushing area. These locations were monitored only during the working hours, while air monitoring was also done at an upwind, {open_quotes}background{close_quotes} area 24-hours per day. The median concentrations of Pu in {open_quotes}workplace{close_quotes} air (combined spoils pile, plant area, and clean pile sites) in 1992 was 397 aCi/m{sup 3} (15 {mu}Bq/m{sup 3}), but increased to median values of 23000 aCi/m{sup 3} (852 {mu}Bq/m{sup 3}) in August-November 1994 and 29800 aCi/m{sup 3} (1100 {mu}Bq/m{sup 3}) in February 1995. The highest median value at the worksites (29800 aCi/m{sup 3}) was more than 200 times lower than the regulatory level. The highest observed value was 84200 aCi/m{sup 3} at the spoils pile site, and this was more than 70 times lower than the regulatory level. The conclusion was that, in spite of the dusty environment, and the increased level of specific activity, we did not find that the soil processing posed any significant risk to workers during the observation periods 1992-1995.

  17. Suspended plutonium aerosols near a soil cleanup site on Johnston Atoll in 1992

    SciTech Connect

    Shinn, J.H.; Fry, C.F.; Johnson, J.S.

    1994-02-01

    Plutonium aerosol monitoring was conducted for one month near the 1992 operation of a stationary sorting system used to {open_quotes}mine{close_quotes} contaminated soil on Johnston Atoll. Pairs of high volume cascade impactors and a high volume air sampler were located at each of three locations of the process stream: the {open_quotes}spoils pile{close_quote} that was the feedstock, the {open_quotes}plant area{close_quotes} near the-hot soil gate of the sorter, and the {open_quotes}clean pile{close_quotes} conveyer area where sorted clean soil was moved. These locations were monitored only during the working hours, while air monitoring was also done at an upwind, uncontaminated {open_quotes}background{close_quotes} area 24-hours per day. The three monitoring locations were extremely dusty, even though there were frequent rains during the period of operation. Total suspended particulate mass loadings were 178 {mu}g/m{sup 3} at the spoils pile, 93 {mu}g/m{sup 3} at the plant area, and 79 {mu}g/m{sup 3} at the clean pile during this period, when background mass loadings were 41 {mu}g/m{sup 3}. There was no practical difference in the aerosol specific activity between the three locations, however, which had a median value of 3.64 pCi/g (135 Bq/kg). The aerosol specific activity is enhanced by a factor of 3 over the specific activity of the processed contaminant soil. This is about the same enhancement factor as found by other studies of road traffic, bulldozing, and agricultural operations. Specific activity of processed soil was 1.35 pCi/g (50 Bq/kg). The median mass-loading of the three downwind sites was 109 {mu}g/m{sup 3} (uncorrected for the sea spray contribution), so that the median concentrations in air using the median aerosol specific activity was calculated to be 397 aCi/m{sup 3} (15 {mu}Bq/m{sup 3}). Measured Pu concentrations ranged from 280 to 1508 aCi/m{sup 3} (10 to 56 {mu}Bq/m3).

  18. Efforts to eradicate yellow crazy ants on Johnston Atoll: Results from Crazy Ant Strike Team IX, December 2014-June 2015

    USGS Publications Warehouse

    Banko, Paul C.; Peck, Robert W.; Donmoyer, Kevin; Kropidlowski, Stephan; Pollock, Amanda

    2015-01-01

    The ecologically destructive yellow crazy ant (YCA; Anoplolepis gracilipes) was first detected on Johnston Atoll in January 2010. Within eight months, the U.S. Fish and Wildlife Service had mobilized its first crazy ant strike team (CAST), a group of biologists dedicated to testing and identifying insecticidal baits to be used to eradicate the ant on the atoll. During December 2014‒May 2015 CAST IX focused on testing hydrogel crystals saturated with sucrose solution (25%) carrying the insecticides thiamethoxam and dinotefuran against YCA. A series of experiments, including artificial nest box trials, and field-based palatability trials and eradication tests on small (500 m2 or 0.05 ha) and large plots (2500 m2 or 0.25 ha), were conducted to test concentrations of thiamethoxam ranging from 0.0005% to 0.01%, and dinotefuran at 0.05%. Additionally, the cat food-based matrix containing dinotefuran (0.05%), the standard bait used to suppress YCA on Johnston since 2011, and textured vegetable protein (TVP) carrying dinotefuran at 0.1% and 0.05% were included in large plot tests. Nest box trials were inconclusive due to a consistent loss of queen and worker ants in control boxes, so they were discontinued. Palatability trials suggested higher dosages of thiamethoxam (0.005 and 0.01%) were less attractive than lower dosages (0.0005 and 0.001%) and controls (sucrose only), but small and large plot experiments failed to identify a thiamethoxam concentration that was consistently effective at killing YCA. In contrast, hydrogel containing dinotefuran was consistently effective, killing >95% of YCA on small and large plots. As expected, the cat food bait effectively reduced YCA abundances, but was slightly less effective than hydrogel containing dinotefuran over time. Three successive, approximately weekly treatments of large plots with hydrogel bait, or other baits followed by hydrogel bait, suggest an increasing overall effectiveness, with no aversion of YCA to the bait

  19. Independent Verification Survey of the Clean Coral Storage Pile at the Johnston Atoll Plutonium Contaminated Soil Remediation Project

    SciTech Connect

    Wilson-Nichols, M.J.; Egidi, P.V.; Roemer, E.K.; Schlosser, R.M.

    2000-09-01

    f I The Oak Ridge National Laboratory (ORNL) Environmental Technology Section conducted an independent verification (IV) survey of the clean storage pile at the Johnston Atoll Plutonium Contaminated Soil Remediation Project (JAPCSRP) from January 18-25, 1999. The goal of the JAPCSRP is to restore a 24-acre area that was contaminated with plutonium oxide particles during nuclear testing in the 1960s. The selected remedy was a soil sorting operation that combined radiological measurements and mining processes to identify and sequester plutonium-contaminated soil. The soil sorter operated from about 1990 to 1998. The remaining clean soil is stored on-site for planned beneficial use on Johnston Island. The clean storage pile currently consists of approximately 120,000 m3 of coral. ORNL conducted the survey according to a Sampling and Analysis Plan, which proposed to provide an IV of the clean pile by collecting a minimum number (99) of samples. The goal was to ascertain wi th 95% confidence whether 97% of the processed soil is less than or equal to the accepted guideline (500-Bq/kg or 13.5-pCi/g) total transuranic (TRU) activity.

  20. Analysis of chemical weapons decontamination waste from old ton containers from Johnston Atoll using multiple analytical methods

    SciTech Connect

    Creasy, W.R.; Brickhouse, M.D.; Morrisse, K.M.

    1999-07-01

    Decontamination waste from chemical weapons (CW) agents has been stored in ton containers on Johnston Atoll since 1971. The waste was recently sampled and analyzed to determine its chemical composition in preparation for future cleanups. Due to the range of products and analytical requirements, multiple chromatographic and spectroscopic methods were necessary, including gas chromatography/mass spectrometry (GC/MS), gas chromatography/atomic emission detection (GC/AED), liquid chromatography/mass spectrometry (LC/MS), capillary electrophoresis (CE), and nuclear magnetic resonance spectroscopy (NMR). The samples were screened for residual agents. No residual sarin (GB) or VX was found to detection limits of 20 ng/mL, but 3% of the samples contained residual sulfur mustard (HD) at < 140 ng/mL. Decontamination products of agents were identified. The majority (74%) of the ton containers were documented correctly, in that the observed decontamination products were in agreement with the labeled agent type, but for a number of the containers, the contents were not in agreement with the labels. In addition, arsenic compounds that are decontamination products of the agent lewisite (L) were observed in a few ton containers, suggesting that lewisite was originally present but not documented. This study was a prototype to demonstrate the level of effort required to characterize old bulk CW-related waste.

  1. Independent Verification Survey of the Clean Coral Storage Pile at the Johnston Atoll Plutonium-Contaminated Soil Remediation Project

    SciTech Connect

    Wilson-Nichols, M.J.

    2000-12-07

    The Oak Ridge National Laboratory (ORNL) Environmental Technology Section conducted an independent verification (IV) survey of the clean storage pile at the Johnston Atoll Plutonium Contaminated Soil Remediation Project (JAPCSRP) from January 18-25, 1999. The goal of the JAPCSRP is to restore a 24-acre area that was contaminated with plutonium oxide particles during nuclear testing in the 1960s. The selected remedy was a soil sorting operation that combined radiological measurements and mining processes to identify and sequester plutonium-contaminated soil. The soil sorter operated from about 1990 to 1998. The remaining clean soil is stored on-site for planned beneficial use on Johnston Island. The clean storage pile currently consists of approximately 120,000 m{sup 3} of coral. ORNL conducted the survey according to a Sampling and Analysis Plan, which proposed to provide an IV of the clean pile by collecting a minimum number (99) of samples. The goal was to ascertain with 95% confidence whether 97% of the processed soil is less than or equal to the accepted guideline (500-Bq/kg or 13.5-pCi/g) total transuranic (TRU) activity. In previous IV tasks, ORNL has (1) evaluated and tested the soil sorter system software and hardware and (2) evaluated the quality control (QC) program used at the soil sorter plant. The IV has found that the soil sorter decontamination was effective and significantly reduced plutonium contamination in the soil processed at the JA site. The Field Command Defense Threat Reduction Agency currently plans to re-use soil from the clean pile as a cover to remaining contamination in portions of the radiological control area. Therefore, ORNL was requested to provide an IV. The survey team collected samples from 103 random locations within the top 4 ft of the clean storage pile. The samples were analyzed in the on-site radioanalytical counting laboratory with an American Nuclear Systems (ANS) field instrument used for the detection of low

  2. Efforts to eradicate yellow crazy ants on Johnston Atoll: Results from crazy ant strike teams X, XI and XII (June 2015–December 2016)

    USGS Publications Warehouse

    Peck, Robert W; Banko, Paul C.; Donmoyer, Kevin; Scheiner, Katrina; Karimi, Rebekah; Kropidlowski, Stefan

    2017-01-01

    Efforts to eradicate invasive yellow crazy ants (Anoplolepis gracilipes; YCA) on Johnston Atoll have been continuous since their discovery in 2010. Through 2014, a variety of commercial and novel formicidal baits were tested against the ant, but none proved capable of eradication. More recently, polyacrylamide crystals (“hydrogel”) saturated with a sucrose solution containing the insecticide dinotefuran has been shown to be effective over large areas when applied against YCA alone or sequentially with a protein-based cat food bait. During June 2015–December 2016, Crazy Ant Strike Teams (CASTs) conducted treatment and monitoring efforts across an infestation of about 57 ha on Johnston Atoll. Following three infestation-wide treatments (primarily using hydrogel) during 2015, YCA were reduced 98% and surviving nests became difficult to find. Subsequently, a protocol designed to detect ants at low abundance that combined hand searching with a high density of baited monitoring stations (12 stations/0.25 ha; HST protocol) was employed within a network of 50 x 50 m cells that subdivided the infestation. During 2016 YCA were found at numerous locations using this method and standard grid-based bait monitoring surveys. Overall, 65 cells where YCA were detected, or cells adjacent to detections, were treated with hydrogel or cat food bait. YCA were not detected during four monitoring events each separated by at least one week, on 85% of these cells after 1–3 treatments, but it was necessary to treat several cells 4–7 times before YCA were eliminated. Results from HST searches allowed us to estimate the probability that YCA were detected when present in an area when searched using that method. Based on this probability, it was determined that areas would have to be searched three times without YCA being detected to allow 93% certainty that the ants were absent. The level of certainty increased to 99% when the search was conducted four times and YCA were not found

  3. Description and epizootiology of Babesia poelea n. sp. in brown boobies (Sula leucogaster (Boddaert)) on Sand Island, Johnston Atoll, Central Pacific

    USGS Publications Warehouse

    Work, Thierry M.; Rameyer, Robert

    1997-01-01

    We describe a new species of piroplasm from brown boobies (Sula leucogaster) on Sand Island, Johnston Atoll National Wildlife Refuge, central Pacific. Mean parasitemia in adults and chicks was less than 1%, with the parasitemia in chicks significantly greater than in adults. There was no significant relation between the age of chicks and the degree of parasitemia. Parasitized red cells and red cell nuclei were significantly smaller than those of unparasitized cells, and infected birds appeared clinically normal. Prevalence of the parasite in chicks (54%) was significantly greater than in adults (13%), and the geographic distribution of parasitized chicks was skewed toward the eastern end of Sand Island. On the basis of morphologic characteristics, we named it Babesia poelea. The specific name is a concatenation of the Hawaiian names for dark (po'ele) and booby ('a). This is the second documentation of an endemic avian hemoparasite in seabirds from the central Pacific.

  4. Description and epizootiology of Babesia poelea n. sp. in brown boobies (Sula leucogaster (Boddaert)) on Sand Island, Johnston Atoll, Central Pacific

    USGS Publications Warehouse

    Work, T.M.; Rameyer, R.A.

    1997-01-01

    We describe a new species of piroplasm from brown boobies (Sula leucogaster) on Sand Island, Johnston Atoll National Wildlife Refuge, central Pacific. Mean parasitemia in adults and chicks was less than 1%, with the parasitemia in chicks significantly greater than in adults. There was no significant relation between the age of chicks and the degree of parasitemia. Parasitized red cells and red cell nuclei were significantly smaller than those of unparasitized cells, and infected birds appeared clinically normal. Prevalence of the parasite in chicks (54%) was significantly greater than in adults (13%), and the geographic distribution of parasitized chicks was skewed toward the eastern end of Sand Island. On the basis of morphologic characteristics, we named it Babesia poelea. The specific name is a concatenation of the Hawaiian names for dark (po'ele) and booby ('a). This is the second documentation of an endemic avian hemoparasite in seabirds from the central Pacific.

  5. Vertical and Horizontal Genetic Connectivity in Chromis verater, an Endemic Damselfish Found on Shallow and Mesophotic Reefs in the Hawaiian Archipelago and Adjacent Johnston Atoll

    PubMed Central

    Tenggardjaja, Kimberly A.; Bowen, Brian W.; Bernardi, Giacomo

    2014-01-01

    Understanding vertical and horizontal connectivity is a major priority in research on mesophotic coral ecosystems (30–150 m). However, horizontal connectivity has been the focus of few studies, and data on vertical connectivity are limited to sessile benthic mesophotic organisms. Here we present patterns of vertical and horizontal connectivity in the Hawaiian Islands-Johnston Atoll endemic threespot damselfish, Chromis verater, based on 319 shallow specimens and 153 deep specimens. The mtDNA markers cytochrome b and control region were sequenced to analyze genetic structure: 1) between shallow (<30 m) and mesophotic (30–150 m) populations and 2) across the species' geographic range. Additionally, the nuclear markers rhodopsin and internal transcribed spacer 2 of ribosomal DNA were sequenced to assess connectivity between shallow and mesophotic populations. There was no significant genetic differentiation by depth, indicating high levels of vertical connectivity between shallow and deep aggregates of C. verater. Consequently, shallow and deep samples were combined by location for analyses of horizontal connectivity. We detected low but significant population structure across the Hawaiian Archipelago (overall cytochrome b: ΦST = 0.009, P = 0.020; control region: ΦST = 0.012, P = 0.009) and a larger break between the archipelago and Johnston Atoll (cytochrome b: ΦST = 0.068, P<0.001; control region: ΦST = 0.116, P<0.001). The population structure within the archipelago was driven by samples from the island of Hawaii at the southeast end of the chain and Lisianski in the middle of the archipelago. The lack of vertical genetic structure supports the refugia hypothesis that deep reefs may constitute a population reservoir for species depleted in shallow reef habitats. These findings represent the first connectivity study on a mobile organism that spans shallow and mesophotic depths and provide a reference point for future connectivity

  6. Vertical and horizontal genetic connectivity in Chromis verater, an endemic damselfish found on shallow and mesophotic reefs in the Hawaiian Archipelago and adjacent Johnston Atoll.

    PubMed

    Tenggardjaja, Kimberly A; Bowen, Brian W; Bernardi, Giacomo

    2014-01-01

    Understanding vertical and horizontal connectivity is a major priority in research on mesophotic coral ecosystems (30-150 m). However, horizontal connectivity has been the focus of few studies, and data on vertical connectivity are limited to sessile benthic mesophotic organisms. Here we present patterns of vertical and horizontal connectivity in the Hawaiian Islands-Johnston Atoll endemic threespot damselfish, Chromis verater, based on 319 shallow specimens and 153 deep specimens. The mtDNA markers cytochrome b and control region were sequenced to analyze genetic structure: 1) between shallow (< 30 m) and mesophotic (30-150 m) populations and 2) across the species' geographic range. Additionally, the nuclear markers rhodopsin and internal transcribed spacer 2 of ribosomal DNA were sequenced to assess connectivity between shallow and mesophotic populations. There was no significant genetic differentiation by depth, indicating high levels of vertical connectivity between shallow and deep aggregates of C. verater. Consequently, shallow and deep samples were combined by location for analyses of horizontal connectivity. We detected low but significant population structure across the Hawaiian Archipelago (overall cytochrome b: ΦST = 0.009, P = 0.020; control region: ΦST = 0.012, P = 0.009) and a larger break between the archipelago and Johnston Atoll (cytochrome b: ΦST = 0.068, P < 0.001; control region: ΦST = 0.116, P < 0.001). The population structure within the archipelago was driven by samples from the island of Hawaii at the southeast end of the chain and Lisianski in the middle of the archipelago. The lack of vertical genetic structure supports the refugia hypothesis that deep reefs may constitute a population reservoir for species depleted in shallow reef habitats. These findings represent the first connectivity study on a mobile organism that spans shallow and mesophotic depths and provide a reference point for future connectivity studies on mesophotic

  7. Johnston Atoll Plutonium Contaminated Soil Cleanup Project. 5th quarterly report, 1 August 94 to 31 October 1994. Technical report, 1 August-31 October 1994

    SciTech Connect

    Doane, R.W.; Grant, R.H.

    1996-09-01

    Thermo NUtech is the prime contractor for the Defense Nuclear Agency (DNA), responsible for the operation and maintenance of the Johnston Atoll plutonium Contaminated Soil Cleanup Project. During this production period, the Scope of Work included movement of soil to and from the plant, processing contaminated soil through the Segmented Gate System (SGS) and Soil Washing System, packaging of waste soil for shipment, identification and implementation of process improvements, data collection and validation, and compliance with all applicable regulations governing environmental safety and health. The SGS utilizes arrays of sensitive radiation detectors coupled with sophisticated computer software to segregate contaminated soil from a moving feed supply on conveyor belts. Contaminated soil is diverted to a `hot path` for plutonium particles greater than 5000 Becquerels or to a supplemental soil washing process designed to remove dispersed low leve%l contamination from a soil faction consisting of very small particles. Low to intermediate levels of contamination are removed from the soil to meet DNA`s criteria for unrestricted use of less than 500 Becquerels per kilogram of soil, with no hot particles. The low level concentrate is expected to be packaged for shipment to an approved defense waste disposal site.

  8. Johnston Atoll Ocean Science Study

    DTIC Science & Technology

    1997-09-30

    bleaching using staining of live colonies and isotopic analysis of specimens (Cohen et al 1997). 9. Completed writing for DoD “ Coral Reef Conservation...establishing a basis for regulatory guidelines for assessing the effects of contaminants on coral reef ecosystems. We have also used our experience to write... Coral Reef Conservation Guide for the Military” for DoD Office of Environmental Security. Thirdly, we have a fully operational underwater radiation

  9. An Ecological Assessment of Johnston Atoll

    DTIC Science & Technology

    2012-01-01

    dinoflagellates live on the surface of other algae, which are eaten by herbivorous fishes. These fishes can then accumulate the toxin. Depending on the level of...maximum size is 11 inches) is an herbivore browser feeding mainly on fine filamentous algae while avoiding ingestion of carbonate sand particles. It digests...size is 7 inches) is the most abundant species overall in the lagoon. All surgeonfishes are herbivores but differ in whether they also ingest sand

  10. An Interview with Ron Johnston.

    ERIC Educational Resources Information Center

    Gold, John R.; Shepherd, Ifan D. H.

    1983-01-01

    Ron Johnston is questioned about his personal and educational backgrounds, career in geography, teaching styles, differences between students in different countries, graduate study in geography, writing books, the use of textbooks, and the role and problems of geography in higher education. (IS)

  11. The Johnston – Kennedy Era

    PubMed Central

    Spence, Roy

    2007-01-01

    The paper by McConville and Crookes1 in this issue of the Journal highlights the contribution of many Ulster surgeons to gastric surgery. The era of Professor George Johnston and Mr Terence Kennedy produced some of the most dramatic changes in surgery of benign upper GI disease. I was a medical student, House Officer, Senior House Officer and then Senior Registrar to these giants of Ulster surgery – these questioning surgeons participated in some of the most important trials of that time in gastric surgery, and assessed scientifically (and independently) the benefits of a logical progression in surgical vagotomy from truncal to selective (with the various drainage procedures) to the highly selective procedure. I would like to take you on a thirty year journey of reflection. PMID:17288296

  12. 33. HISTORIC PLAQUE MARKING WHERE JOHNSTON DIED, ADJACENT TO PATHWAY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    33. HISTORIC PLAQUE MARKING WHERE JOHNSTON DIED, ADJACENT TO PATHWAY WITH CONCRETE CULVERT LEADING NORTH OUT OF RAVINE TOWARD JOHNSTON MEMORIAL SITE. VIEW NW. - Shiloh National Military Park Tour Roads, Shiloh, Hardin County, TN

  13. Development of Johnston's organ in Drosophila.

    PubMed

    Eberl, Daniel F; Boekhoff-Falk, Grace

    2007-01-01

    Hearing is a specialized mechanosensory modality that is refined during evolution to meet the particular requirements of different organisms. In the fruitfly, Drosophila, hearing is mediated by Johnston's organ, a large chordotonal organ in the antenna that is exquisitely sensitive to the near-field acoustic signal of courtship songs generated by male wing vibration. We summarize recent progress in understanding the molecular genetic determinants of Johnston's organ development and discuss surprising differences from other chordotonal organs that likely facilitate hearing. We outline novel discoveries of active processes that generate motion of the antenna for acute sensitivity to the stimulus. Finally, we discuss further research directions that would probe remaining questions in understanding Johnston's organ development, function and evolution.

  14. Johnstone's "Wedge" and Theory of Rhetoric.

    ERIC Educational Resources Information Center

    Arnold, Carroll C.

    1987-01-01

    Presents the views of a scholar in speech communication on Henry Johnstone's ideas about rhetoric. Concludes that rhetoric that "appeals" wedges apart percipient and objects of perception, or that it forces a person to examine what he or she knows or is, as well as examining the proffered rhetoric. (NKA)

  15. The Palmyra Atoll Research Consortium

    USGS Publications Warehouse

    Suchanek, Thomas H.

    2012-01-01

    Palmyra functions as a living laboratory. It is a low-lying coral atoll located about 1,800 kilometers south/southwest of Hawaii near the equator in the central Pacific Ocean (latitude 5°53'N, longitude 162°05'W). Palmyra Atoll and nearby Kingman Reef are U.S. territories and represent the northern atolls/reefs of the U.S. Line Islands. Palmyra also is one of the nine sovereign territories of the United States commonly referred to as the U.S. Pacific Remote Island Areas (PRIAs) that straddle the equator (fig. 1). Palmyra Atoll and nearby Kingman Reef also were included as part of the seven territories that comprise the Pacific Remote Islands Marine National Monument set aside by President Bush in 2009 (Proclamation 8336), which includes the same territories as the PRIAS, except Rose Atoll and Midway Atoll.

  16. Utirik Atoll Dose Assessment

    SciTech Connect

    Robison, W.L.; Conrado, C.L.; Bogen, K.T

    1999-10-06

    On March 1, 1954, radioactive fallout from the nuclear test at Bikini Atoll code-named BRAVO was deposited on Utirik Atoll which lies about 187 km (300 miles) east of Bikini Atoll. The residents of Utirik were evacuated three days after the fallout started and returned to their atoll in May 1954. In this report we provide a final dose assessment for current conditions at the atoll based on extensive data generated from samples collected in 1993 and 1994. The estimated population average maximum annual effective dose using a diet including imported foods is 0.037 mSv y{sup -1} (3.7 mrem y{sup -1}). The 95% confidence limits are within a factor of three of their population average value. The population average integrated effective dose over 30-, 50-, and 70-y is 0.84 mSv (84, mrem), 1.2 mSv (120 mrem), and 1.4 mSv (140 mrem), respectively. The 95% confidence limits on the population-average value post 1998, i.e., the 30-, 50-, and 70-y integral doses, are within a factor of two of the mean value and are independent of time, t, for t > 5 y. Cesium-137 ({sup 137}Cs) is the radionuclide that contributes most of this dose, mostly through the terrestrial food chain and secondarily from external gamma exposure. The dose from weapons-related radionuclides is very low and of no consequence to the health of the population. The annual background doses in the U. S. and Europe are 3.0 mSv (300 mrem), and 2.4 mSv (240 mrem), respectively. The annual background dose in the Marshall Islands is estimated to be 1.4 mSv (140 mrem). The total estimated combined Marshall Islands background dose plus the weapons-related dose is about 1.5 mSv y{sup -1} (150 mrem y{sup -1}) which can be directly compared to the annual background effective dose of 3.0 mSv y{sup -1} (300 mrem y{sup -1}) for the U. S. and 2.4 mSv y{sup -1} (240 mrem y{sup -1}) for Europe. Moreover, the doses listed in this report are based only on the radiological decay of {sup 137}Cs (30.1 y half-life) and other

  17. Molecular phylogeny of Babesia poelea from brown boobies (Sula leucogaster) from Johnston Atoll, Central Pacific

    USGS Publications Warehouse

    Yabsley, Michael J.; Work, Thierry M.; Rameyer, Robert A.

    2006-01-01

    The phylogenetic relationship of avian Babesia with other piroplasms remains unclear, mainly because of a lack of objective criteria such as molecular phylogenetics. In this study, our objective was to sequence the entire 18S, ITS-1, 5.8S, and ITS-2 regions of the rRNA gene and partial ß-tubulin gene of B. poelea, first described from brown boobies (Sula leucogaster) from the central Pacific, and compare them to those of other piroplasms. Phylogenetic analyses of the entire 18S rRNA gene sequence revealed that B. poelea belonged to the clade of piroplasms previously detected in humans, domestic dogs, and wild ungulates in the western United States. The entire ITS-1, 5.8S, ITS-2, and partial ß-tubulin gene sequence shared conserved regions with previously described Babesia and Theileria species. The intron of the ß-tubulin gene was 45 bp. This is the first molecular characterization of an avian piroplasm.

  18. Molecular phylogeny of Babesia poelea from brown boobies (Sula leucogaster) from Johnston Atoll, central Pacific

    USGS Publications Warehouse

    Yabsley, M.J.; Work, T.M.; Rameyer, R.A.

    2006-01-01

    The phylogenetic relationship of avian Babesia with other piroplasms remains unclear, mainly because of a lack of objective criteria such as molecular phylogenetics. In this study, our objective was to sequence the entire 18S, ITS-1, 5.8S, and ITS-2 regions of the rRNA gene and partial ??-tubulin gene of B. poelea, first described from brown boobies (Sula leucogaster) from the central Pacific, and compare them to those of other piroplasms. Phylogenetic analyses of the entire 18S rRNA gene sequence revealed that B. poelea belonged to the clade of piroplasms previously detected in humans, domestic dogs, and wild ungulates in the western United States. The entire ITS-1, 5.8S, ITS-2, and partial ??-tubulin gene sequence shared conserved regions with previously described Babesia and Theileria species. The intron of the ??-tubulin gene was 45 bp. This is the first molecular characterization of an avian piroplasm. ?? American Society of Parasitologists 2006.

  19. Johnston Atoll Plutonium Contaminated Soil Cleanup Project. Quarterly report No. 3, 7 February-30 April 1994

    SciTech Connect

    Doane, R.W.; Grant, R.H.

    1996-11-01

    During this production period, the Scope of Work included movement of soil to and from the plant, processing contaminated soil through the Segmented Gate System (SGS) and Soil Washing System, packaging of waste soil for shipment, identification and implementation of process improvements, data collection and validation, and compliance with all applicable regulations governing environmental safety and health. The SGS utilizes arrays of sensitive radiation detectors coupled with sophisticated computer software to segregate contaminated soil from a moving feed supply on conveyor belts. Contaminated soil is diverted to a `hot` path for plutonium particles greater than 5000 Becquerels or to a supplemental soil washing process designed to remove dispersed low level contamination from a soil faction consisting of very small particles. Low to intermediate levels of contamination are removed from the soil to meet DNA`s criteria for unrestricted use of less than 500 Becquerels per kilogram of soil, with no `hot` particles.

  20. Circulation in Enewetak Atoll lagoon

    SciTech Connect

    Atkinson, M.; Smith, S.V.; Stroup, E.D.

    1981-11-01

    Currents at Enewetak Atoll, Marshall Islands, were measured on the reef margins, in the channels, and in the lagoon. Lagoon circulation is dominated by wind-driven downwind surface flow and an upwind middepth return flow. This wind-driven flow has the characteristics of an Ekman spiral in an enclosed sea. Lagoon flushing is accomplished primarily by surf-driven water input over the windward (eastern) reefs and southerly drift out the South Channel. Mean water residence time is 1 month, while water entering the northern portion of the atoll takes about 4 months to exit.

  1. Growing plants on atoll soils

    SciTech Connect

    Stone, E L; Migvar, L; Robison, W L

    2000-02-16

    Many years ago people living on atolls depended entirely on foods gathered from the sea and reefs and grown on land. Only a few plants, such as coconut (ni), Pandanus (bob), and arrowroot (mok-mok), could be grown on the lower rainfall atolls, although adequate groundwater conditions also allowed taro (iaraj, kotak, wot) to be cultivated. On higher rainfall atolls, breadfruit (ma) was a major food source, and banana (binana, kepran), lime (laim), and taros (iaraj, kotak, wot) could be grown. The early atoll populations were experts in growing plants that were vital to sustaining their nutrition requirements and to providing materials for thatch, basketry, cordage, canoe construction, flowers, and medicine. They knew which varieties of food plants grew well or poorly on their atolls, how to propagate them, and where on their atoll they grew best. They knew the uses of most native plants and what the various woods were well suited for. Many varieties of Pandanus (bob) and breadfruit (ma) grew well with high rainfall, but only a few produced well on drier atolls. Such information had been passed down through the generations although some of it has been lost in the last century. Today there are new plants and new varieties of existing plants that can be grown on atolls. There are also new materials and information on how to grow both the old and new plants more effectively. However, there are also introduced weeds and pests to control. Today, there is also an acute need to grow more of the useful plants adapted to atolls. Increasing numbers of people living on an atoll without an equal increase in income or food production stretches the available food supplies. Much has been written about the poor conditions for plant growth on atolls. As compared with many places in the world where crops are grown, however, atolls can provide some highly favorable conditions. For instance, the driving force for plant growth is sunlight, and on atolls light is abundant throughout the

  2. Biosecurity Plan for Palmyra Atoll

    USGS Publications Warehouse

    Hathaway, Stacie A.; Fisher, Robert N.

    2010-01-01

    This Biosecurity Plan for Palmyra Atoll was developed for The Nature Conservancy (TNC) Palmyra Program to refine and expand goals and objectives developed through the Conservation Action Plan process. The Biosecurity Plan is one in a series of adaptive management plans designed to achieve TNC's mission toward the protection and enhancement of native wildlife and habitat. The Biosecurity Plan focuses on ecosystem security, and specifically identifies and addresses issues related to non-native and potentially invasive species. The Plan attempts to identify pathways of invasion and strategies for preventing or reducing new introductions. Overall, the Biosecurity Plan provides a framework to implement and track the progress of conservation and restoration goals related to non-native species on Palmyra Atoll. Palmyra Atoll is one of the Northern Line Islands in the Pacific Ocean southwest of the Hawai`ian Islands. It consists of many heavily vegetated islets arranged in a horseshoe pattern around four lagoons and surrounded by a coral reef. At present, Palmyra Atoll harbors various non-native or invasive species in the terrestrial and marine ecosystems. The most notable examples of terrestrial invasive species include coconut trees (Cocos nucifera) and black rats (Rattus rattus). Although it is unclear whether they are non-native, coconut trees are currently the most dominant plant across Palmyra Atoll. They compete with native plant species for space and resources, and are potentially detrimental to seabirds dependent on native vegetation. Black rats are known to predate ground-nesting seabirds and are likely responsible for the lack of burrowing seabird reproduction on Palmyra Atoll. The most notable example of a marine invasive species is the corallimorph (Rhodactis howsei). Although Rhodactis howsei is a native species, it can take advantage of human-altered habitat and significantly change the natural habitat by aggressively outcompeting native corals. Although the

  3. Coupling the Sorkin-Johnston state to gravity

    NASA Astrophysics Data System (ADS)

    Avilán, Nicolás; Reyes-Lega, Andrés F.; Carneiro da Cunha, Bruno

    2014-10-01

    We consider the dynamics of the Sorkin-Johnston state for a massless scalar field in two dimensions. We conduct a study of the renormalized stress-tensor by a subtraction procedure, and compare the results with those of the conformal vacuum, with an important contribution from correction term. We find a large trace anomaly and compute backreaction effects to two dimensional (Liouville) gravity. We also find a natural interpretation for the mirror behavior of the Sorkin-Johnston state described in previous works.

  4. Johnston and Gause Discuss Student Proposed Skylab Experiment

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Roger Johnston (right), high school student from St. Paul Minnesota, discussed his proposed Skylab experiment 'Capillary Action Studies in a State of Free Fall', with Dr. Raymond Gause of the Marshall Space Flight Center (MSFC). Johnston was among 25 winners of a contest in which some 3,500 high school students proposed experiments for the following year's Skylab mission. The nationwide scientific competition was sponsored by the National Science Teachers Association and the National Aeronautics and Space Administration (NASA). The winning students, along with their parents and sponsor teachers, visited MSFC earlier where they met with scientists and engineers, participated in design reviews for their experiments, and toured MSFC facilities. Of the 25 students, 6 did not see their experiments conducted on Skylab because the experiments were not compatible with Skylab hardware and timelines. Of the 19 remaining, 11 experiments required the manufacture of additional equipment.

  5. AIDS education reaches Pacific atolls.

    PubMed

    1994-01-01

    The Republic of Kiribati consists of 33 islands and 69,000 inhabitants dispersed over a large area of the Central Pacific. It includes the former Gilbert Islands, which were linked as British colonies with the Ellice Islands until the latter declared themselves independent as Tuvalu. Kiribati became independent from Britain in 1979 and joined WHO [the World Health Organization] in 1984. Launched in 1988, the national AIDS program is now implementing its second medium-term plan. As part of this plan, the program recently held its first AIDS awareness workshop for hotel workers, health care workers and youth. The workshop was held on Kiritimati, the world's largest atoll. Also known as Christmas Island, the atoll of 2650 inhabitants has excellent bird-watching and fishing opportunities, which have drawn growing numbers of tourists in recent years. Although neither of the two HIV infections identified in Kiribati by March 1994 were on Kiritimati, the prevalence of other sexually transmitted diseases there has been on the rise. Meeting in a traditional thatched building, the workshop participants proved eager to learn about HIV and STDs [sexually transmitted diseases]. They received instruction in prevention skills, including a demonstration of proper condom use led by the national AIDS coordinator. At the close of the workshop, condoms were provided to hotel staff for distribution.

  6. Cleanup, Rehabilitation, Resettlement of Enewetak Atoll - Marshall Islands. Volume I.

    DTIC Science & Technology

    required to resettle the Enewetak people in the Atoll after 25-30 years of absence. During the post World War II period, the Atoll was used as a...The intent of the project is to remove or reduce those existing conditions which would be a bar to safe habitation of the Atoll and to return the Enewetak people to the Atoll ....inhabitants from the Atoll , the creation of hazards, both physical and radiological, and the consequent loss of much of the productive capacity of the Atoll

  7. Removal of transuranics from Johnston Island soil by fractional classification

    SciTech Connect

    Sunderland, N.R.

    1987-06-07

    The following conclusions were reached as a result of the research conducted with the TRUclean process on Johnston Island: Processed materials will have a total TRU activity of less than 500 Bq/Kg. Approximately 90% of the TRU activity in coral/soil is removed by a single pass through the fractional classification process. A volume reduction of greater than 90% of the original contaminated volume can be achieved with the returned ''clean'' volume less than or equal to the cleanup criteria. Reprocessing or multiple staging of the process units will yield overall efficiencies of greater than 90%. Continued testing at Nevada Test Site confirmed these conclusions.

  8. Decontamination of Johnston Island Coral: a preliminary study

    SciTech Connect

    Kochen, R.L.

    1986-02-17

    A preliminary investigation was completed on the characterization and decontamination of coral samples from Johnston Island. These samples were found to contain individual particles (2 to 0.25 mm) of contaminated coral as well as a piece of contaminated magnetic metal. They ranged in activity from about 70 to 811 nCi Am-241. The decontamination methods investigated were froth flotation, ferrite treatment, attrition scrubbing, ultrasonic treatment and dry sieving. Dry sieving, the more effective technique, separated about 42 wt % of the coral into a decontaminated fraction. This fraction (>4 mm) contained about 0.5% of the total activity. 7 refs., 3 tabs.

  9. Roger Johnston Discusses Skylab Experiment With NASA Personnel

    NASA Technical Reports Server (NTRS)

    1972-01-01

    St. Paul Minnesota high school student, Roger Johnston (center), Gene Vacca (left) of NASA Headquarters, and Ann Whitaker of the Marshall Space Flight Center (MSFC) discuss the equipment to be used for the student's experiment, 'Capillary Action Studies in a State of Free Fall', to be performed aboard the Skylab the following year. Johnston was among 25 winners of a contest in which some 3,500 high school students proposed experiments for the following year's Skylab mission. The nationwide scientific competition was sponsored by the National Science Teachers Association and the National Aeronautics and Space Administration (NASA). The winning students, along with their parents and sponsor teachers, visited MSFC two months earlier where they met with scientists and engineers, participated in design reviews for their experiments, and toured MSFC facilities. Of the 25 students, 6 did not see their experiments conducted on Skylab because the experiments were not compatible with Skylab hardware and timelines. Of the 19 remaining, 11 experiments required the manufacture of additional equipment. The equipment for the experiments was manufactured at MSFC.

  10. Resettlement of Bikini Atoll U.S. Nuclear Test Site

    SciTech Connect

    Robinson, W.L.; Conrado, C.L.; Stuart, M.L.; Stoker, A.C.; Hamilton, T.F.

    1999-09-09

    The US conducted a nuclear testing program at Bikini and Enewetak Atolls in the Marshall Islands from 1946 through 1958. Several atolls, including Bikini, were contaminated as a result of the nuclear detonations. Since 1974 the authors have conducted an extensive research and monitoring program to determine the radiological conditions at the atolls, identify the critical radionuclides and pathways, estimate the radiological dose to current or resettling populations, and develop remedial measures to reduce the dose to atoll populations. This paper describes exposure pathways and radionuclides; composition of atoll soils; radionuclide transport and dose estimates; remedial measures; and reduction in dose from a combined option.

  11. Current radiological status of Utirik Atoll

    SciTech Connect

    Robison, W L

    1998-08-01

    A preliminary radiological survey was conducted at Utirik Atoll in 1978 as part of the Northern Marshall Islands Radiological Survey (NMIRS). A dose assessment based on these limited data indicated a relatively low dose of about 0.12 mSv to people living on Utirik in 1978 (Robison et al., 1982). A much more detailed radiological survey was conducted in April of both 1993 and 1994. Aerial photos of the islands of Utirik Atoll were taken as part of the 1978 NMIRS. The sampling grids for the 1993 and 1994 surveys are shown overlaid on these aerial photos in Figures 1, 2, 3, and 4. External gamma measurements and a collection of either drinking coconuts or copra coconuts were made at each location. Pandanus, breadfruit, lime, and banana were collected where available. Ground water was collected in 1993/94 from four wells on Utirik Island and two wells on Aon Island. Surface soil and soil profiles were collected at some of the grid points on each of the islands at the atoll in 1993/94. A comparison of the number of samples collected in 1978 and 1993/94 are shown in Table 1. A detailed listing of the samples collected in the 1993/94 radiological survey at Utirik Atoll is given in Table 2. The number of vegetation samples collected in 1993/94 is nearly a factor of 7 greater than in 1978. Soil samples collected in 1993/94 exceeded the number collected in 1978 by more than a factor of 4. Consequently, extensive data are now available for the islands at Utirik Atoll and form the basis for the current dose assessment for the atoll.

  12. 50 CFR 665.931 - Boundaries.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., Baker, Howland, and Jarvis Islands, Johnston Atoll, Kingman Reef, and Palmyra Atoll, is defined as...″ 0°28′39″ N. (d) Johnston Atoll. The Johnston Atoll unit of the Monument includes the waters and submerged and emergent lands around Johnston Atoll within an area defined by straight lines connecting...

  13. 50 CFR 665.931 - Boundaries.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., Baker, Howland, and Jarvis Islands, Johnston Atoll, Kingman Reef, and Palmyra Atoll, is defined as...″ 0°28′39″ N. (d) Johnston Atoll. The Johnston Atoll unit of the Monument includes the waters and submerged and emergent lands around Johnston Atoll within an area defined by straight lines connecting...

  14. [Corynosoma cetaceum Johnston and Best, 1942 (Acanthocephala) in Chilean dolphin, Cephalorhynchus entropia Gray, 1846 (Cetacea: Delphinidae)].

    PubMed

    Figueroa, L; Puga, S

    1990-01-01

    The finding of Corynosoma cetaceum Johnston and Best 1942, as a parasite of Cephalorhynchus eutropia Gray, 1846, is reported. This constitutes the first record of this acanthocephala in a new host, as well a new geographic distribution.

  15. Water Quality of a Micronesian Atoll

    ERIC Educational Resources Information Center

    Mabbett, Arthur N.

    1975-01-01

    In 1972, a water quality survey of the eastern end of Majuro Atoll, Marshall Islands was conducted to determine the water quality of selected lagoon and open ocean sites and provide guidance for the construction of a sewerage system. This study revealed that lagoon waters were moderately to severely contaminated. (BT)

  16. Water Quality of a Micronesian Atoll

    ERIC Educational Resources Information Center

    Mabbett, Arthur N.

    1975-01-01

    In 1972, a water quality survey of the eastern end of Majuro Atoll, Marshall Islands was conducted to determine the water quality of selected lagoon and open ocean sites and provide guidance for the construction of a sewerage system. This study revealed that lagoon waters were moderately to severely contaminated. (BT)

  17. Sustainable use of groundwater in Atoll Islands

    NASA Astrophysics Data System (ADS)

    Taniguchi, M.; Nakada, S.; Umezawa, Y.; Yamano, H.

    2010-12-01

    Water resources in small islands, such as atoll islands, are limited and threatened by climate change such as changes in precipitation and sea level rise. Groundwater is the main water resources in many atoll islands, and the freshwater in aquifers in coral atolls, where the average elevations are a few meters above the sea level, exists as lenses f1oating on salt water. Decrease in precipitation and groundwater recharge is caused by the climate change, increases of storm surge, and excessive groundwater extractions due to over population. There is high possibility that the aquifer salinization can damage the important natural ambience for the people living habitat such as crops field and vegetation. In this study, the aquifer salinization is evaluated by using electrical resistivity, hydrological and long-term meteorological data in two low-lying coral atolls, Laura islet, Majuro Atoll, Marshall islands and Fongafale islet, Funafuti atoll, Tuvalu. Hydrological surveys conducted in Laura islet showed that the interface between seawater and freshwater is shallowed in Aug 2009. This may be attributed to the result of recent decrease of the decadal rainfall and/or the sea level rise. The detailed structure of the freshwater lens based on the electrical resistivity surveys showed patches of brackish water due to the intrusion of seawater and over-pumping. The clear intrusion of the saltwater was observed near the lagoon coast which might be inf1uenced by the recirculation of the seawater in the margin of the freshwater lens. The recirculation was confirmed based on the analysis of the submarine groundwater discharge (SGD) observed by seepage meters. On the other hand, in Fongatale islet, the geoelectric and hydrological surveys conducted in March 2009 showed that the soil and groundwater salinization was mainly caused by the tidal forcing during spring tides. The decrease of the resistivity during the f1ood tide indicates the coastal aquifer beneath the islet is

  18. Terrestrial forest management plan for Palmyra Atoll

    USGS Publications Warehouse

    Hathaway, Stacie A.; McEachern, Kathryn; Fisher, Robert N.

    2011-01-01

    This 'Terrestrial Forest Management Plan for Palmyra Atoll' was developed by the U.S. Geological Survey (USGS) for The Nature Conservancy (TNC) Palmyra Program to refine and expand goals and objectives developed through the Conservation Action Plan process. It is one in a series of adaptive management plans designed to achieve TNC's mission toward the protection and enhancement of native wildlife and habitat. The 'Terrestrial Forest Management Plan for Palmyra Atoll' focuses on ecosystem integrity and specifically identifies and addresses issues related to assessing the status and distribution of resources, as well as the pressures acting upon them, most specifically nonnative and potentially invasive species. The plan, which presents strategies for increasing ecosystem integrity, provides a framework to implement and track the progress of conservation and restoration goals related to terrestrial resources on Palmyra Atoll. The report in its present form is intended to be an overview of what is known about historical and current forest resources; it is not an exhaustive review of all available literature relevant to forest management but an attempt to assemble as much information specific to Palmyra Atoll as possible. Palmyra Atoll is one of the Northern Line Islands in the Pacific Ocean southwest of the Hawai`ian Islands. It consists of many heavily vegetated islets arranged in a horseshoe pattern around four lagoons and surrounded by a coral reef. The terrestrial ecosystem consists of three primary native vegetation types: Pisonia grandis forest, coastal strand forest, and grassland. Among these vegetation types, the health and extent of Pisonia grandis forest is of particular concern. Overall, the three vegetation types support 25 native plant species (two of which may be extirpated), 14 species of sea birds, six shore birds, at least one native reptile, at least seven native insects, and six native land crabs. Green and hawksbill turtles forage at Palmyra Atoll

  19. Removal of transuranics from Johnston Island soil by fractional classification

    SciTech Connect

    Sunderland, N.R.

    1987-01-01

    A decontamination pilot plant was designed, constructed, and successfully operated on Johnston Island from November 20, 1985, to June 14, 1986. The process used in this pilot plant, the AWC TRUclean Process, first successfully removed transuranics (i.e., plutonium and americium isotopes) from the island's coral soil on December 16, 1985, at 1700 h. The process included instrumentation of detect /sup 241/Am with an array of detectors over the incoming contaminated material as well as an array of detectors over the outgoing decontaminated material. Confirming measurements were made by high-resolution intrinsic germanium detectors coupled to multichannel analyzers and by radiochemical analyses. The purpose of the plant was to provide research and development follow-up to a feasibility study that procedures. In addition, the pilot plant was to demonstrate its effectiveness in transuranium removal and provide sufficient information to permit the field command of the Defense Nuclear Agency to determine the cost-effectiveness of decontaminating the soil versus complete radioactive waste disposal and new soil procurement.

  20. An unusual mortality event in Johnstone River snapping turtles Elseya irwini (Johnstone) in Far North Queensland, Australia.

    PubMed

    Ariel, E; Freeman, A B; Elliott, E; Wirth, W; Mashkour, N; Scott, J

    2017-10-01

    An unusual mortality event in Johnstone River snapping turtles (Elseya irwini) in Far North Queensland, Australia, occurred during the summer months of December 2014 and January 2015. We report the data collected during the mortality event, including counts of sick and dead animals, clinical appearance and one necropsy. Moribund animals appeared lethargic with variable degrees of necrotising dermatitis. Postmortem investigation of one freshly dead animal revealed bacterial and fungal involvement in the skin lesions as well as multifocal fibrinous hepatitis and splenitis and necrotising enteritis with vascular thrombosis. Aeromonas hydrophila was isolated from liver, spleen and skin lesions. All samples tested negative for ranavirus, and water and soil testing for environmental contaminants were negative. All affected E. irwini either died or were euthanased and no other species of animals in the river were affected. Aeromonas hydrophila is ubiquitous in the freshwater environment and although it caused septicaemia in the one individual that was submitted for laboratory diagnosis, the primary aetiology of the outbreak may not have been identified. © 2017 Australian Veterinary Association.

  1. Multidecadal shoreline changes of atoll islands in the Marshall Islands

    NASA Astrophysics Data System (ADS)

    Ford, M.

    2012-12-01

    Atoll islands are considered highly vulnerable to the impacts of continued sea level rise. One of the most commonly predicted outcomes of continued sea level rise is widespread and chronic shoreline erosion. Despite the widespread implications of predicted erosion, the decadal scale changes of atoll island shorelines are poorly resolved. The Marshall Islands is one of only four countries where the majority of inhabited land is comprised of reef and atoll islands. Consisting of 29 atolls and 5 mid-ocean reef islands, the Marshall Islands are considered highly vulnerable to the impacts of sea level rise. A detailed analysis of shoreline change on over 300 islands on 10 atolls was undertaken using historic aerial photos (1945-1978) and modern high resolution satellite imagery (2004-2012). Results highlight the complex and dynamic nature of atoll islands, with significant shifts in shoreline position observed over the period of analysis. Results suggest shoreline accretion is the dominant mode of change on the islands studied, often associated with a net increase in vegetated island area. However, considerable inter- and intra-atoll variability exists with regards to shoreline stability. Findings are discussed with respect to island morphodynamics and potential hazard mitigation and planning responses within atoll settings.

  2. Geohydrology of Enewetak Atoll islands and reefs

    SciTech Connect

    Buddemeier, R.W.

    1981-05-06

    Extensive tidal studies in island wells and the lagoon at Enewetak Atoll have shown that island ground water dynamics are controlled by a layered aquifer system. The surface aquifer of unconsolidated Holocene material extends to a depth of approximately 15 m, and has a hydraulic conductivity K = 60 m/day. From 15 to 60 m (approximate lagoon depth) the reef structure consists of successive layers of altered Pleistocene materials, with bulk permeability substantially higher than that of the surface aquifer. Because of wave set-up over the windward reef and the limited pass area for outflow at the south end of the atoll, lagoon tides rise in phase with the ocean tides but fall later than the ocean water level. This results in a net lagoon-to-ocean head which can act as the driving force for outflow through the permeable Pleistocene aquifer. This model suggests that fresh water, nutrients or radioactive contaminants found in island ground water or reef interstitial water may be discharged primarily into the ocean rather than the lagoon. Atoll island fresh water resources are controlled by recharge, seawater dilution due to vertical tidal mixing between the surface and deeper aquifers, and by loss due to entrainment by the outflowing water in the deeper aquifers. Estimated lagoon-ot-ocean transit times through the deep aquifer are on the order of a few years, which corresponds well to the freshwater residence time estimates based on inventory and recharge. Islands in close proximity to reef channels have more fresh ground water than others, which is consistent with a locally reduced hydraulic gradient and slower flow through the Pleistocene aquifers.

  3. Kiernan reentry measurements system on Kwajalein atoll

    SciTech Connect

    Roth, K.R.; Austin, M.E.; Frediani, D.J.; Knittel, G.H.; Mrstik, A.V.

    1989-01-01

    The Kiernan Reentry Measurements System (KREMS), located on Kwajalein Atoll in the Pacific, is the United States' most sophisticated and important research and development radar site. Consisting of four one-of-a-kind instrumentation radars, KREMS has played a major role for the past 25 years in the collection of data associated with ICBM testing. Furthermore, it has served as an important space-surveillance facility that provides an early U.S. view of many Soviet and Chinese satellite launches. Finally, the system is slated to play a key role in Strategic Defense Initiative experiments.

  4. Dolomitization of the Mid-Pacific Atolls.

    PubMed

    Berner, R A

    1965-03-12

    The origin of the dolomite which occurs beneath the atolls of Funafuti, Kita-daitō-jima, and Eniwetok in the Pacific Ocean can be explained by the reaction of hypersaline brines with transported or buried reef skeletal material. Dolomitization could have taken place at the sediment surface in shallow restricted back-reef lagoons and tidal flats or below the surface by reflux action. Measurements of oxygen isotopes in samples of dolomite can be interpreted as indicating an origin from evaporated, isotopically-heavy sea water.

  5. Cenozoic sea level and the rise of modern rimmed atolls

    USGS Publications Warehouse

    Toomey, Michael; Ashton, Andrew; Raymo, Maureen E.; Perron, J. Taylor

    2016-01-01

    Sea-level records from atolls, potentially spanning the Cenozoic, have been largely overlooked, in part because the processes that control atoll form (reef accretion, carbonate dissolution, sediment transport, vertical motion) are complex and, for many islands, unconstrained on million-year timescales. Here we combine existing observations of atoll morphology and corelog stratigraphy from Enewetak Atoll with a numerical model to (1) constrain the relative rates of subsidence, dissolution and sedimentation that have shaped modern Pacific atolls and (2) construct a record of sea level over the past 8.5 million years. Both the stratigraphy from Enewetak Atoll (constrained by a subsidence rate of ~ 20 m/Myr) and our numerical modeling results suggest that low sea levels (50–125 m below present), and presumably bi-polar glaciations, occurred throughout much of the late Miocene, preceding the warmer climate of the Pliocene, when sea level was higher than present. Carbonate dissolution through the subsequent sea-level fall that accompanied the onset of large glacial cycles in the late Pliocene, along with rapid highstand constructional reef growth, likely drove development of the rimmed atoll morphology we see today.

  6. 77 FR 42903 - Change in Definitions; Evacuation Pay and the Separate Maintenance Allowance at Johnston Island

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-20

    ... Maintenance Allowance at Johnston Island AGENCY: U.S. Office of Personnel Management. ACTION: Final rule. SUMMARY: The U.S. Office of Personnel Management is revising its regulations on evacuation pay and the... policy expressed in the President's June 2, 2010, memorandum on the ``Extension of Benefits to...

  7. Atoll-scale patterns in coral reef community structure: Human signatures on Ulithi Atoll, Micronesia.

    PubMed

    Crane, Nicole L; Nelson, Peter; Abelson, Avigdor; Precoda, Kristin; Rulmal, John; Bernardi, Giacomo; Paddack, Michelle

    2017-01-01

    The dynamic relationship between reefs and the people who utilize them at a subsistence level is poorly understood. This paper characterizes atoll-scale patterns in shallow coral reef habitat and fish community structure, and correlates these with environmental characteristics and anthropogenic factors, critical to conservation efforts for the reefs and the people who depend on them. Hierarchical clustering analyses by site for benthic composition and fish community resulted in the same 3 major clusters: cluster 1-oceanic (close proximity to deep water) and uninhabited (low human impact); cluster 2-oceanic and inhabited (high human impact); and cluster 3-lagoonal (facing the inside of the lagoon) and inhabited (highest human impact). Distance from village, reef exposure to deep water and human population size had the greatest effect in predicting the fish and benthic community structure. Our study demonstrates a strong association between benthic and fish community structure and human use across the Ulithi Atoll (Yap State, Federated States of Micronesia) and confirms a pattern observed by local people that an 'opportunistic' scleractinian coral (Montipora sp.) is associated with more highly impacted reefs. Our findings suggest that small human populations (subsistence fishing) can nevertheless have considerable ecological impacts on reefs due, in part, to changes in fishing practices rather than overfishing per se, as well as larger global trends. Findings from this work can assist in building local capacity to manage reef resources across an atoll-wide scale, and illustrates the importance of anthropogenic impact even in small communities.

  8. Geochemistry of manganese nodules from offshore areas of Mariana Islands and Johnston Island

    NASA Astrophysics Data System (ADS)

    Chen, Ju-chin; Yao, Yung-chang

    The manganese nodules near the Mariana Islands generally range from 2 to 4 cm in diameter and some samples have porous surfaces. The nodules near Johnston Island are larger in size (5-8 cm in diameter) and more compact than the Mariana nodules. The major FeMn minerals found in Mariana Islands samples are todorokite, birnessite and akaganeite (β-FeOOH) while, in the Johnston Island samples, only birnessite and akaganeite are found. The Mariana Islands nodules are higher in Mn, Mg, Na, K, Co, Ni, Pb and Th but lower in Fe, Sr, Zn, Ba, Zr, Y and REEs than the Johnston Island samples. The (Cu + Ni + Co) contents of the Mariana Islands samples are generally higher than 15,000 ppm with {Co}/{Zn} ratios varying from 10 to 15, while the Johnston Island samples generally have (Cu + Ni + Co) between 8000 and 10,000 ppm with {Co}/{Zn} ratios varying from 5 to 7. Therefore these nodules may not be related to hydrothermal activity (Toth, Geol. Soc. Am. Bull.91, 44-54, 1980). Both the Mariana Islands and Johnston Island nodules show similar LREE-enriched patterns with distinct positive Ce anomaly and negative Eu anomaly. The positive correlation between the Ce anomaly defined as log {Ce}/{{2}/{3}La+ {1}/{3}Nd } and {Mn}/{Fe} ratios found in the nodules studied suggest that a phosphorus-rich phase with REE pattern similar to that for biogenous apatite may be the third component in considering the source of REEs in the nodules. The growth rate determined by the excess 230Th method for Johnston Island nodule JA-1, from 0.2 to 0.45 mm depth, is 1.12±0.10 mm/Ma but a much higher rate (17.66 ± 7.61 mm/Ma) is observed from 0.45 to 1.8 mm depth. The growth rate of the nodule may be related to its Mn and Fe contents.

  9. Radiological Conditions on Rongelap Atoll: Diving and Fishing on and Around Rongelap Atoll

    SciTech Connect

    Hamilton, T F

    2003-02-01

    Rongelap Atoll experienced close-in ''local fallout'' from nuclear weapons tests conducted by the United States (1946-58) in the northern Marshall Islands. Most of the radiation dose delivered to Rongelap Island residents during the 1950s was from radioactive elements that quickly decayed into non-radioactive elements. Since 1985, the Lawrence Livermore National Laboratory (LLNL) has continued to provide monitoring of radioactive elements from bomb testing in the terrestrial and marine environment of Rongelap Atoll. The only remaining radioactive elements of environmental importance at the atoll are radioactive cesium (cesium-137), radioactive strontium (strontium-90), different types (isotopes) of plutonium, and americium (americium-241). Cesium- 137 and strontium-90 dissolve in seawater and are continually flushed out of the lagoon into the open ocean. The small amount of residual radioactivity from nuclear weapons tests remaining in the lagoon does not concentrate through the marine food chain. Elevated levels of cesium-137 and strontium-90 are still present in island soils and pose a potential health risk if certain types of local plants and coconut crabs are eaten in large quantities. Cesium-137 is taken up from the soil into plants and edible food products, and may end up in the body of people living on the islands and consuming local food. The presence of cesium-137 in the human body can be detected using a device called a whole body counter. A person relaxes in a chair for a few minutes while counts or measurements are taken using a detector a few inches away from the body. The whole body counting program on Rongelap Island was established in 1999 under a cooperative agreement between the Rongelap Atoll Local Government (RALG), the Republic of the Marshall Islands and the U.S. Department of Energy (DOE). Local technicians from Rongelap continue to operate the facility under supervision of scientists from LLNL. The facility permits resettlement workers

  10. Spatial and temporal controls of atoll island inundation: implications for urbanized atolls in the Marshall Islands.

    NASA Astrophysics Data System (ADS)

    Ford, M.; Becker, J. M.; Merrifield, M. A.

    2012-12-01

    Atoll islands are highly vulnerable to a range of inundation hazards. The impacts of such hazards are expected to be magnified as a result of continued sea-level rise. Both recent and historic inundation events provide unique insights into the requisite conditions necessary to initiate island inundation. A number of recent and historic inundation events are presented in order to examine the oceanographic and meteorological conditions driving inundation of a densely populated, urbanized atoll in the central Pacific. Analysis of inundation events suggests that a number of key drivers contribute to the spatial and temporal extent of island inundation, with unique degrees of predictability and resultant impact signatures apparent on island geomorphology and local anthropogenic activities. Results indicate three distinct drivers of inundation hazards exist. Firstly, tropical storms and typhoons elevate sea level through inverse barometric setup, wind setup and a range of wave driven processes and have caused considerable impact on atolls within the Marshall Islands. Secondly, super-elevated sea level conditions resulting from the combination of seasonal high tides and quasi-cyclical La Nina conditions drive inundation of low-lying lagoon facing coastal areas. Thirdly, long period swell conditions, typically generated by distant storms, can elevate reef-flat water levels through wave setup and infragravity wave oscillations. Such wave conditions can over wash the ocean-facing island ridge, often inundating large sections of the island. Reef-flat wave conditions are tidally modulated, with inundation events typically occurring around high tide. However, the two most recent destructive swell-driven inundation events have occurred while tide levels were significantly lower than spring tide levels, suggesting high water levels are not a necessary prerequisite for wave-driven inundation. The different modes of inundation are discussed and grounded within recent and historic

  11. Clipperton, a possible future for atoll lagoons

    NASA Astrophysics Data System (ADS)

    Charpy, L.; Rodier, M.; Couté, A.; Perrette-Gallet, C.; Bley-Loëz, C.

    2010-09-01

    Closure of the Clipperton Island atoll (10°17' N 109°13' W), now a meromictic lake, is estimated to have occurred between 1839 and 1849. It was still closed in 2005. Brackish waters in the upper layer (0-10 m) were oxygenated, while saline waters in the deep layer (>20 m) were anoxic. Allowing for the methodological difficulties of earlier measurements, the physical characteristics of the lagoon did not seem to have changed significantly since the last expedition (1980). The intermediate layer between brackish and saline waters was characterized by a strong density gradient and a temperature inversion of up to 1.6°C. Microbial activity, water exchange between the deep layer and surrounding oceanic waters and the geothermal flux hypothesis are discussed. The low DIN and SRP concentrations observed in the upper layer, despite high nutrient input by seabird droppings, reflect the high nutrient uptake by primary producers as attested by the elevated overall gross primary production (6.6 g C m-2 day-1), and high suspended photosynthetic biomass (2.23 ± 0.23 μg Chl a l-1) and production (263 ± 27 μg C l-1 day-1). Phytoplankton composition changed in 67 years with the advent of new taxa and the disappearance of previously recorded species. The freshwater phytoplanktonic community comprised 43 taxa: 37 newly identified during the expedition and 6 previously noted; 16 species previously found were not seen in 2005. The closure of the lagoon, combined with the positive precipitation-evaporation budget characteristic of the region, has induced drastic changes in lagoon functioning compared with other closed atolls.

  12. Numerical modeling of atoll island hydrogeology.

    PubMed

    Bailey, R T; Jenson, J W; Olsen, A E

    2009-01-01

    We implemented Ayers and Vachers' (1986) inclusive conceptual model for atoll island aquifers in a comprehensive numerical modeling study to evaluate the response of the fresh water lens to selected controlling climatic and geologic variables. Climatic factors include both constant and time-varying recharge rates, with particular attention paid to the effects of El Niño and the associated drought it brings to the western Pacific. Geologic factors include island width; hydraulic conductivity of the uppermost Holocene-age aquifer, which contains the fresh water lens; the depth to the contact with the underlying, and much more conductive, Pleistocene karst aquifer, which transmits tidal signals to the base of the lens; and the presence or absence of a semiconfining reef flat plate on the ocean side. Sensitivity analyses of steady-steady simulations show that lens thickness is most strongly sensitive to the depth to the Holocene-Pleistocene contact and to the hydraulic conductivity of the Holocene aquifer, respectively. Comparisons between modeling results and published observations of atoll island lens thicknesses suggest a hydraulic conductivity of approximately 50 m/d for leeward islands and approximately 400 m/d for windward islands. Results of transient simulations show that lens thickness fluctuations during average seasonal conditions and El Niño events are quite sensitive to island width, recharge rate, and hydraulic conductivity of the Holocene aquifer. In general, the depletion of the lens during drought conditions is most drastic for small, windward islands. Simulation results suggest that recovery from a 6-month drought requires about 1.5 years.

  13. Wavelet decomposition of forced turbulence: Applicability of the iterative Donoho-Johnstone threshold

    NASA Astrophysics Data System (ADS)

    Lord, Jesse W.; Rast, Mark P.; Mckinlay, Christopher; Clyne, John; Mininni, Pablo D.

    2012-02-01

    We examine the decomposition of forced Taylor-Green and Arn'old-Beltrami-Childress (ABC) flows into coherent and incoherent components using an orthonormal wavelet decomposition. We ask whether wavelet coefficient thresholding based on the Donoho-Johnstone criterion can extract a coherent vortex signal while leaving behind Gaussian random noise. We find that no threshold yields a strictly Gaussian incoherent component, and that the most Gaussian incoherent flow is found for data compression lower than that achieved with the fully iterated Donoho-Johnstone threshold. Moreover, even at such low compression, the incoherent component shows clear signs of large-scale spatial correlations that are signatures of the forcings used to drive the flows.

  14. The Sorkin–Johnston state in a patch of the trousers spacetime

    NASA Astrophysics Data System (ADS)

    Buck, Michel; Dowker, Fay; Jubb, Ian; Sorkin, Rafael

    2017-03-01

    A quantum scalar field in a patch of a fixed, topology-changing, 1+1 dimensional ‘trousers’ spacetime is studied using the Sorkin–Johnston formalism. The isometry group of the patch is the dihedral group, the symmetry group of the square. The theory is shown to be pathological in a way that can be interpreted as the topology change giving rise to a divergent energy, in agreement with previous results. In contrast to previous results, it is shown that the infinite energy is localised not only on the future light cone of the topology changing singularity, but also on the past cone, due to the time reversal symmetry of the Sorkin–Johnston state.

  15. 77 FR 61426 - Rose Atoll National Wildlife Refuge, American Samoa; Draft Comprehensive Conservation Plan and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-09

    ... Fish and Wildlife Service Rose Atoll National Wildlife Refuge, American Samoa; Draft Comprehensive... Assessment (Draft CCP/EA) for the Rose Atoll National Wildlife Refuge (NWR/refuge) for public review and.../planning.html . Email: FW1PlanningComments@fws.gov . Include ``Rose Atoll National Wildlife Refuge Draft...

  16. Atoll Research Bulletin No. 136. Coral Islands of the Western Indian Ocean,

    DTIC Science & Technology

    birds on Farquhar and Providence; Geography and ecology of Cosmoledo Atoll; Plants of Cosmoledo Atoll; Land (including shore) birds of Cosmoledo...Geography and ecology of Astove; Plants of Astove; Note on the Lepidoptera of Astove Atoll; Land (including shore) birds of Astove; Ecological change and

  17. Atoll-scale patterns in coral reef community structure: Human signatures on Ulithi Atoll, Micronesia

    PubMed Central

    Nelson, Peter; Abelson, Avigdor; Precoda, Kristin; Rulmal, John; Bernardi, Giacomo; Paddack, Michelle

    2017-01-01

    The dynamic relationship between reefs and the people who utilize them at a subsistence level is poorly understood. This paper characterizes atoll-scale patterns in shallow coral reef habitat and fish community structure, and correlates these with environmental characteristics and anthropogenic factors, critical to conservation efforts for the reefs and the people who depend on them. Hierarchical clustering analyses by site for benthic composition and fish community resulted in the same 3 major clusters: cluster 1–oceanic (close proximity to deep water) and uninhabited (low human impact); cluster 2–oceanic and inhabited (high human impact); and cluster 3–lagoonal (facing the inside of the lagoon) and inhabited (highest human impact). Distance from village, reef exposure to deep water and human population size had the greatest effect in predicting the fish and benthic community structure. Our study demonstrates a strong association between benthic and fish community structure and human use across the Ulithi Atoll (Yap State, Federated States of Micronesia) and confirms a pattern observed by local people that an ‘opportunistic’ scleractinian coral (Montipora sp.) is associated with more highly impacted reefs. Our findings suggest that small human populations (subsistence fishing) can nevertheless have considerable ecological impacts on reefs due, in part, to changes in fishing practices rather than overfishing per se, as well as larger global trends. Findings from this work can assist in building local capacity to manage reef resources across an atoll-wide scale, and illustrates the importance of anthropogenic impact even in small communities. PMID:28489903

  18. A reconnaissance approach for hydrology of atoll lagoons

    NASA Astrophysics Data System (ADS)

    Pagès, J.; Andréfouët, S.

    2001-12-01

    As a reconnaissance tool of the hydrology of atoll lagoons in the micro-tidal environment of the Tuamotu Archipelago, we define and compute "potential" flow rates at lagoon scale under three swell regimes (high, average, and low swell) after assessment of orientation and width of reef-flat spillways using satellite images. As a direct test, the "potential" flows were compared with field measurements of (1) measured inflows across the reef flat (for eight atolls), (2) net outgoing flow through the pass (for three atolls), and (3) lagoon-level variation rates (for four atolls). Absolute values of "potential" and field flows agreed ( r 2=0.94, n=42, slope ~1). Computed average water renewal times (TRAV) were also tested against concentrations of dissolved organic matter (DOM). DOM and TRAV were positively correlated ( r 2=0.54, n=26; Spearman's rs=0.54), and this relationship should enable the detection of unusual atolls. This approach would then appear to be useful for the reconnaissance of hydrodynamics processes in comparable micro-tidal environments.

  19. Individual Radiation Protection Monitoring in the Marshall Islands. Utrok Atoll (2010-2012)

    SciTech Connect

    Hamilton, T. F.; Kehl, S. R.; Martinelli, R. E.; Hickman, R. E.; Hickman, D. P.; Tumey, S. J.; Brown, T. A.; Langston, R. G.; Tamblin, M. W.; Tibon, S.; Chee, L.; Aisek, Jr., A.; DeDrum, Z.; Mettao, M.; Henson, J.

    2014-12-15

    As a hard copy supplement to the Marshall Islands Program website (https://marshallislands.llnl.gov), this document provides an overview of the individual radiological surveillance monitoring program established in support of residents of Utrōk Atoll and nonresident citizens of the Utrōk Atoll population group, along with full disclosure of verified measurement data (2010-2012). The Utrōk Atoll Whole Body Counting Facility has been temporarily stationed on Majuro Atoll and, in cooperation with the Utrōk Atoll Local Government, serves as a national radiological facility open to the general public.

  20. Distant storms as drivers of environmental change at Pacific atolls.

    PubMed

    Gardner, Jonathan P A; Garton, David W; Collen, John D; Zwartz, Daniel

    2014-01-01

    The central Pacific Ocean with its many low lying islands and atolls is under threat from sea level rise and increased storm activity. Here, we illustrate how increasing frequency and severity of large scale storm events associated with global climate change may be particularly profound at the local scale for human populations that rely on lagoon systems for provision of a variety of goods and services. In August 2011 a storm originating in the Southern Ocean caused a large amplitude ocean swell to move northward through the Pacific Ocean. Its arrival at Palmyra Atoll coincided with transient elevated sea surface height and triggered turnover of the lagoon water column. This storm-induced change to the lagoon reflects long distance connectivity with propagated wave energy from the Southern Ocean and illustrates the increasing threats generated by climate change that are faced by human populations on most low-lying Pacific islands and atolls.

  1. Distant Storms as Drivers of Environmental Change at Pacific Atolls

    PubMed Central

    Gardner, Jonathan P. A.; Garton, David W.; Collen, John D.; Zwartz, Daniel

    2014-01-01

    The central Pacific Ocean with its many low lying islands and atolls is under threat from sea level rise and increased storm activity. Here, we illustrate how increasing frequency and severity of large scale storm events associated with global climate change may be particularly profound at the local scale for human populations that rely on lagoon systems for provision of a variety of goods and services. In August 2011 a storm originating in the Southern Ocean caused a large amplitude ocean swell to move northward through the Pacific Ocean. Its arrival at Palmyra Atoll coincided with transient elevated sea surface height and triggered turnover of the lagoon water column. This storm-induced change to the lagoon reflects long distance connectivity with propagated wave energy from the Southern Ocean and illustrates the increasing threats generated by climate change that are faced by human populations on most low-lying Pacific islands and atolls. PMID:24498232

  2. The ecosystem study on Rongelap Atoll

    SciTech Connect

    Walker, R.B.; Gessel, S.P.; Held, E.E.

    1997-07-01

    During the 1950`s and 1960`s, the Laboratory of Radiation Biology at the University of Washington carried out an intensive study of this Atoll, which was contaminated with radioactive fallout from the {open_quotes}Bravo shot{close_quotes} in 1954. This study involved many aspects of the environment and the plant and animal life: soils, land plants, marine life, birds, geology and hydrology, and human diets as well. In much of the research, the fortuitiously present radioactive isotopes, especially {sup 137}Cs and {sup 90}Sr, were tracers. Although the term {open_quotes}ecosystem study{close_quotes} was not in vogue at that time, it is clear that this was an early use of the ecosystem approach. Soil types and their development, the distribution of mineral elements in plants and soils, including predominant radionuclides, distribution and growth of native terrestrial plants in relation to topography and salinity, some aspects of the human diets, micronutrient nutrition of the coconut palm, island and islet development and stability, were given attention in the studies. Some of the findings in the various areas of study will be presented and discussed. 32 refs., 2 figs., 8 tabs.

  3. Corynosoma australe Johnston, 1937 and C. cetaceum Johnston & Best, 1942 (Acanthocephala: Polymorphidae) from marine mammals and fishes in Argentinian waters: allozyme markers and taxonomic status.

    PubMed

    Sardella, Norma H; Mattiucci, Simonetta; Timi, Juan T; Bastida, Ricardo O; Rodríguez, Diego H; Nascetti, Giuseppe

    2005-06-01

    Genetic and morphological studies were carried out on acanthocephalans belonging to Corynosoma Lühe, 1904 and referable to the species C. cetaceum Johnston & Best, 1942 and C. australe Johnston, 1937, which were recovered from both definitive and intermediate hosts in Argentinian waters. The aims were to estimate the level of genetic differentiation between the two taxa at any stage of their life-cycle, to provide genetic (allozyme) markers for their recognition and to analyse the systematic status of both taxa. Acanthocephalans were collected from the stomach and intestine of Arctocephalus australis (Zimmerman), the intestine of Mirounga leonina (Linnaeus) and the stomach of Pontoporia blainvillei Gervais & D'Orbigny (definitive hosts) in Argentinian waters. Alternative alleles at all the 13 enzymatic loci studied were observed for C. australe and C. cetaceum. The specimens from the stomach of both P. blainvillei and A. australis were identified, on the basis of the great number of diagnostic loci found, as C. cetaceum; those from intestine of both A. australis and M. leonina as C. australe. A high level of genetic differentiation (D(Nei)=infinity: I(Nei)=0.00) between the two taxa was found, suggesting a generic distinction between the two species. Cystacanths of the two species from the body-cavity of the fish Cynoscion guatucupa (Cuvier) collected from the same geographical area were identified genetically. Morphological patterns, such as the number of hooks and hook rows on the proboscis, the distribution of somatic and genital armature, and other morphometric and meristic differences, in addition to ecological data, enabled the identification of these two species at cystacanth, juvenile and adult stages. However, a number of morphological and morphometric features of the Argentinian material were different to those of C. australe and C. cetaceum described from other regions of the world.

  4. Numerical modelling of geothermal and reflux circulation in Enewetak Atoll: Implications for dolomitization

    USGS Publications Warehouse

    Jones, G.; Whitaker, F.; Smart, P.; Sanford, W.

    2000-01-01

    Two types of regional-scale seawater circulation have been proposed to explain the formation of Enewetak Atoll dolomites: geothermal and reflux circulation. We have used a finite element groundwater flow model to examine the pattern, magnitude and dynamic interaction of these two different circulation mechanisms in Enewetak Atoll. Geothermal circulation is concentrated around the atoll-margin whereas refluxing mesosaline brines flow from the atoll interior towards the margin to restrict and eventually shut off geothermal circulation. Refluxing brines of 36-80??? can account for the salinity signature recorded in dolomite fluid inclusions. Distributions of fluid flux and Mg mass-balance calculations suggest that both geothermal and reflux circulation mechanisms could account for the observed distribution of dolomite in Enewetak Atoll. Furthermore, the atoll interior may be extensively dolomitized as observed in other atolls. (C) 2000 Elsevier Science B.V. All rights reserved.Two types of regional-scale seawater circulation have been proposed to explain the formation of Enewetak Atoll dolomites: geothermal and reflux circulation. We have used a finite element groundwater flow model to examine the pattern, magnitude and dynamic interaction of these two different circulation mechanisms in Enewetak Atoll. Geothermal circulation is concentrated around the atoll-margin whereas refluxing mesosaline brines flow from the atoll interior towards the margin to restrict and eventually shut off geothermal circulation. Refluxing brines of 36-80 per mil can account for the salinity signature recorded in dolomite fluid inclusions. Distributions of fluid flux and Mg mass-balance calculations suggest that both geothermal and reflux circulation mechanisms could account for the observed distribution of dolomite in Enewetak Atoll. Furthermore, the atoll interior may be extensively dolomitized as observed in other atolls.

  5. 5 CFR 591.205 - Which areas are nonforeign areas?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., and Jarvis Islands; (7) Johnston Atoll; (8) Kingman Reef; (9) Midway Atoll; (10) Navassaa Island; (11) Palmyra Atoll; (12) Territory of Guam; (13) United States Virgin Islands; (14) Wake Atoll; (15) Any...

  6. 5 CFR 591.205 - Which areas are nonforeign areas?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., and Jarvis Islands; (7) Johnston Atoll; (8) Kingman Reef; (9) Midway Atoll; (10) Navassaa Island; (11) Palmyra Atoll; (12) Territory of Guam; (13) United States Virgin Islands; (14) Wake Atoll; (15) Any...

  7. 5 CFR 591.205 - Which areas are nonforeign areas?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., and Jarvis Islands; (7) Johnston Atoll; (8) Kingman Reef; (9) Midway Atoll; (10) Navassaa Island; (11) Palmyra Atoll; (12) Territory of Guam; (13) United States Virgin Islands; (14) Wake Atoll; (15) Any...

  8. 5 CFR 591.205 - Which areas are nonforeign areas?

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., and Jarvis Islands; (7) Johnston Atoll; (8) Kingman Reef; (9) Midway Atoll; (10) Navassaa Island; (11) Palmyra Atoll; (12) Territory of Guam; (13) United States Virgin Islands; (14) Wake Atoll; (15) Any...

  9. 5 CFR 591.205 - Which areas are nonforeign areas?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., and Jarvis Islands; (7) Johnston Atoll; (8) Kingman Reef; (9) Midway Atoll; (10) Navassaa Island; (11) Palmyra Atoll; (12) Territory of Guam; (13) United States Virgin Islands; (14) Wake Atoll; (15) Any...

  10. A Moment in Time--The Scottish Contribution to Progressivism in Art and Education: The Work of William Johnstone, Artist and Art Educator (1897-1981).

    ERIC Educational Resources Information Center

    MacDonald, Stuart Wyllie

    1995-01-01

    Describes the career of Scottish artist and art educator William Johnstone (1897-1981) and how his achievements, which are traced to 20th-century modernism, have influenced both art design and childrens' art education. Concludes that through Johnstone, progressivism in art and education converged, producing a model for creative expression in art…

  11. Strontium-isotope stratigraphy of Enewetak Atoll

    USGS Publications Warehouse

    Ludwig, K. R.; Halley, Robert B.; Simmons, Kathleen R.; Peterman, Zell E.

    1988-01-01

    87Sr/86Sr ratios determined for samples from a 350 m core of Neogene lagoonal, shallow-water limestones from Enewetak Atoll display a remarkably informative trend. Like the recently published data for Deep Sea Drilling Project (DSDP) carbonates, 87Sr/86Sr at Enewetak increases monotonically but not smoothly from the early Miocene to the Pleistocene. The data show intervals of little or no change in 87Sr/86Sr, punctuated by sharp transitions to lower values toward greater core depths. The sharp transitions correlate with observed solution disconformities caused by periods of subaerial erosion, whereas the intervals of little or no change in 87Sr/86Sr correspond to intervals of rapid accumulation of shallow-water carbonate sediments. When converted to numerical ages using the published DSDP 590B trend, the best-resolved time breaks are at 282 m (12.3 to 18.2 Ma missing) and 121.6 m (3.0 to 5.3 Ma missing) below the lagoon floor. At Enewetak, Sr isotopes offer a stratigraphic resolution for these shallow-marine Neogene carbonates comparable to that of nannofossil zonation in deep-sea carbonates (0.3-3 m.y.). In addition, the correlation of times of Sr-isotope breaks at Enewetak with times of rapid Sr-isotope change in the DSDP 590B samples confirms the importance off sea-level changes in the evolution of global-marine Sr isotopes and shows that the Sr-isotope response to sea-level falls is rapid.

  12. Strontium-isotope stratigraphy of Enewetak Atoll

    NASA Astrophysics Data System (ADS)

    Ludwig, K. R.; Halley, R. B.; Simmons, K. R.; Peterman, Z. E.

    1988-02-01

    87Sr/86Sr ratios determined for samples from a 350 m core of Neogene lagoonal, shallow-water limestones from Enewetak Atoll display a remarkably informative trend. Like the recently published data for Deep Sea Drilling Project (DSDP) carbonates, 87Sr/86Sr at Enewetak increases monotonically but not smoothly from the early Miocene to the Pleistocene. The data show intervals of little or no change in 87Sr/86Sr, punctuated by sharp transitions to lower values toward greater core depths. The sharp transitions correlate with observed solution disconformities caused by periods of subaerial erosion, whereas the intervals of little or no change in 87Sr/86Sr correspond to intervals of rapid accumulation of shallow-water carbonate sediments. When converted to numerical ages using the published DSDP 590B trend, the best-resolved time breaks are at 282 m (12.3 to 18.2 Ma missing) and 121.6 m (3.0 to 5.3 Ma missing) below the lagoon floor. At Enewetak, Sr isotopes offer a stratigraphic resolution for these shallow-marine Neogene carbonates comparable to that of nannofossil zonation in deep-sea carbonates (0.3-3 m.y.). In addition, the correlation of times of Sr-isotope breaks at Enewetak with times of rapid Sr-isotope change in the DSDP 590B samples confirms the importance off sea-level changes in the evolution of global-marine Sr isotopes and shows that the Sr-isotope response to sea-level falls is rapid.

  13. Metals in Laysan albatrosses from Midway Atoll.

    PubMed

    Burger, J; Gochfeld, M

    2000-02-01

    We examined the concentrations of lead, cadmium, selenium, chromium, manganese, arsenic, tin, and mercury in the heart, liver, kidney, salt gland, and feathers of adult (n = 10) and young (n = 15) Laysan albatrosses (Diomedea immutabilis) from Midway Atoll in the north-central Pacific Ocean. Lead poisoning has been reported in some Laysans nesting near buildings on Midway, but other heavy metals have not been examined. We examined tissue distribution of metals by age and gender (adults only). We also examined tissue concentrations in three birds with a droop-wing syndrome characteristic of lead poisoning. We compared metal levels in salt gland (a special excretory organ of marine birds) with those in other tissues. All metals varied significantly across tissues in both adults and chicks, and the relative tissue concentrations were similar in adults and chicks for most metals. Adults had higher levels of most metals in most organs, with significant differences mainly for cadmium (up to 20 x higher in kidney and salt gland) and for mercury (17 x higher in kidney). However, chicks had significantly higher manganese in liver and arsenic in salt gland. The salt gland had concentrations of most metals (except cadmium, selenium, and mercury) comparable to the kidney levels, which is consistent with it serving as an excretory organ for the cations. Chicks with droop-wings had very elevated levels of lead in their tissue (16.8 ppm in feathers, 14 ppm in liver and kidney), whereas levels of other metals were not significantly different from the apparently normal chicks.

  14. Radiologoical Conditions on Rongelap Atoll: Recommendations for Visiting and Food Gathering on the Norhtern Islands of Rongelap Atoll

    SciTech Connect

    Hamliton, T F

    2003-02-01

    Rongelap Atoll experienced close-in or local fallout from the U.S. nuclear test program conducted in the northern Marshall Islands between 1946 and 1958. By all internationally agreed scientific criteria, Rongelap Island is considered safe for permanent resettlement. However, the amount of bomb-related radioactivity in soil and vegetation is, on average, about 5 times greater in the northern islands of the atoll because the centerline of the fallout pattern from the 1954 thermonuclear ''Bravo'' test extended over this part of the atoll. The most important radioactive element remaining on the atoll is radioactive cesium (cesium-137). Cesium-137 emits what is called a ''gamma ray'' that can penetrate the body and deliver both an external (outside the body) and internal (from inside the body) gamma dose to inhabitants of Rongelap Atoll. Cesium-137 is taken up from the soil into locally grown foodstuffs such as coconut, Pandanus and breadfruit. Significant quantities of cesium-137 may also be found in coconut crab. The internal dose delivered to people eating these products will be directly proportional to the concentration of cesium-137 in the food and the amount consumed. The external gamma dose will depend on the concentration of cesium-137 in the soil and the amount of time spent in the area. The highest concentration of cesium-137 in surface soils of the northern islands of Rongelap Atoll is about equivalent to that measured on Bikini Island. Under the radiation protection criteria adopted by the Republic of the Marshall Islands Nuclear Claims Tribunal, permanent resettlement of these islands would require intervention because of the higher radiation doses that could potentially be delivered to inhabitants living on a diet derived largely from local foods. A more realistic lifestyle scenario is that the resettled population on Rongelap Island will occasionally visit the northern part of the atoll for food gathering, fishing and other recreational activities. It is

  15. Neogene biostratigraphy and paleoenvironments of Enewetak Atoll, equatorial Pacific Ocean

    USGS Publications Warehouse

    Cronin, T. M.; Bybell, L.M.; Brouwers, E.M.; Gibson, T.G.; Margerum, R.; Poore, R.Z.

    1991-01-01

    Micropaleontologic analyses of Neogene sediments from Enewetak Atoll, Marshall Islands, provide data on the age of lagoonal deposits, stratigraphic disconformities and the paleoenvironmental and subsidence history of the atoll. Benthic foraminifers, planktic foraminifers, calcareous nannofossils and ostracodes were studied from six boreholes, the deepest penetrating 1605 feet below the lagoon floor into upper Oligocene strata. The Oligocene-Miocene boundary occurs at about 1200 ft below the lagoon floor. The early and middle Miocene is characterized by brief periods of deposition and numerous hiatuses. Ostracodes and benthic foraminifers indicate a shallow-marine reefal environment with occasional brackish water conditions. Upper Miocene and lower Pliocene deposits placed in calcareous nannofossil Zones NN9-15 and in planktic foraminifer Zones N16-19 contain species-rich benthic microfaunas which indicate alternating reefal and brackish water mangrove environments. The upper Pliocene contains at least two major depositional hiatuses that coincide with a major faunal turnover in benthic foraminiferal and ostracode assemblages. The Quaternary is characterized by benthic microfaunas similar to those of modern atoll lagoons and is punctuated by at least 11 disconformities which signify periods of low sea level. Atoll subsidence rates during the last 10 Ma averaged 30 to 40 m/m.y. ?? 1991 Elsevier Science Publishers B.V. All rights reserved.

  16. Wave dynamics of a Pacific Atoll with high frictional effects

    NASA Astrophysics Data System (ADS)

    Rogers, Justin S.; Monismith, Stephen G.; Koweek, David A.; Dunbar, Robert B.

    2016-01-01

    We report field measurements of waves and currents made from September 2011 to July 2014 on Palmyra Atoll in the central Pacific that were used in conjunction with the SWAN wave model to characterize the wave dynamics operant on the atoll. Our results indicate that wave energy is primarily from the north during the northern hemisphere winter and from the south in the northern hemisphere summer. Refraction of waves along the reef terraces due to variations in bathymetry leads to focusing of waves in specific locations. Bottom friction, modeled with a modified bottom roughness formulation, is the significant source of wave energy dissipation on the atoll, a result that is consistent with available observations of wave damping on Palmyra. Indeed modeled wave dissipation rates from bottom friction are on average larger than dissipation rates due to breaking and are an order of magnitude larger than what has been observed on other, less geometrically complex reefs, a result which should be corroborated with future in situ measurements. The SWAN wave model with a modified bottom friction formulation better predicts bulk wave energy properties than the existing formulation at our measurement stations. The near bed squared velocity, a proxy for bottom stress, shows strong spatial variability across the atoll and exerts control over geomorphic structure and benthic community composition.

  17. Johnston Island air quality monitoring systems user's guide: System description and standard operating procedures

    SciTech Connect

    Martins, S.

    1991-02-01

    This document is an overview of Monitor Labs air-quality monitoring systems installed at the Johnston Island JCAD Facility during 1990 by personnel from Lawrence Livermore National Laboratory (LLNL). All Johnston Island personnel involved with air-quality monitoring should become familiar with this document. It supplements other training and documentation. This report is written from a user's standpoint and assumes that the reader has some familiarity with air-quality systems. It represents a consolidation of information from many different sources, including training classes video tapes, Monitor Labs manuals, personal experiences with the systems, and verbal communications with Monitor Labs employees. This document includes background information on the project and descriptions of the systems and all components; it makes suggestions for daily, weekly, and quarterly standard operating procedures; it details the installation and tests performed by LLNL/Monitor Labs personnel in bringing the systems on-line; it gives the current status of the systems; and it provides suggestions for future modifications and/or additions. 7 figs.

  18. Tom Johnston's Parliament on Education: The Birth of the Sixth Advisory Council on Education in Scotland, 1942-43.

    ERIC Educational Resources Information Center

    Lloyd, John

    1984-01-01

    Under Secretary of State Thomas Johnston's leadership, the Council considered seven wide-ranging issues in education and produced a series of exemplary reports directed at reforms capable of speedy translation into practice. In the post-war period, the Council lost its influence and the Scottish Education Department returned to its traditional…

  19. 78 FR 76596 - Proposed Levels of Service at Locks and Dams on the J Bennett Johnston Waterway (Red River)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-18

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF DEFENSE Department of the Army; Corps of Engineers Proposed Levels of Service at Locks and Dams on the J Bennett... Dam on the J Bennett Johnston Waterway will remain at the current schedule of 24 hours per day, 7...

  20. Radiological Conditions on Rongelap Atoll: Perspective on Resettlement of Rongelap Atoll

    SciTech Connect

    Hamilton, T F

    2003-02-01

    The most widely accepted international guidelines for protection of the public from ionizing radiation and in circumstances related to intervention strategies to reduce exposures to preexisting conditions, such as those on Rongelap Island, come from the International Commission on Radiological Protection, the National Council on Radiation Protection and the International Atomic Energy Agency. By all internationally agreed scientific criteria, present radiological conditions on Rongelap Island are considered safe for permanent resettlement. Safe implies that no additional cancer deaths are expected among those living on Rongelap Island beyond the number that would occur in a community of the same population size, similar ages and mix of males and females, who do not experience exposure to residual fallout by living on the island. It is expected that the average dose received by Rongelap Island residents will fall well below the dose adopted by the Republic of the Marshall Islands Nuclear Claims Tribunal considered a ''safe'' or acceptable health risk. These conclusions are supported by environmental measurements and assessments performed by the Lawrence Livermore National Laboratory (LLNL) including the results of radiological surveillance of resettlement workers living on Rongelap Island for various lengths of time from 1999 through 2002, and independent studies conducted by Japanese scientists. Atmospheric testing of nuclear weapons was responsible for the widespread dispersion of radioactive fallout around the globe. Rongelap Island received higher levels of fallout from local or close-in fallout deposition from nuclear testing on Bikini Atoll. The main pathway for exposure to radiation from the bomb testing is ''internally'' through ingestion of radioactive cesium (cesium-137) taken up from the soil into locally grown foodstuffs. Resettlement workers living on Rongelap Island who ate local foods have volunteered to have the cesium-137 content of their bodies

  1. Morphological, molecular and phylogenetic analyses of the spirurid nematode Stegophorus macronectes (Johnston & Mawson, 1942).

    PubMed

    Vidal, V; Ortiz, J; Diaz, J I; Zafrilla, B; Bonete, M J; Ruiz De Ybañez, M R; Palacios, M J; Benzal, J; Valera, F; De La Cruz, C; Motas, M; Bautista, V; Machordom, A; Barbosa, A

    2016-03-01

    Stegophorus macronectes (Johnston & Mawson, 1942) is a gastrointestinal parasite found in Antarctic seabirds. The original description of the species, which was based only on females, is poor and fragmented with some unclear diagnostic characters. This study provides new morphometric and molecular data on this previously poorly described parasite. Nuclear rDNA sequences (18S, 5.8S, 28S and internal transcribed spacer (ITS) regions) were isolated from S. macronectes specimens collected from the chinstrap penguin Pygoscelis antarctica Forster on Deception Island, Antarctica. Using 18S rDNA sequences, phylogenetic analyses (maximum likelihood, maximum parsimony and Bayesian inference) of the order Spirurida were performed to determine the phylogenetic location of this species. Primer pairs of the ITS regions were designed for genus-level identification of specimens, regardless of their cycle, as an alternative to coprological methods. The utility of this molecular method for identification of morphologically altered specimens is also discussed.

  2. Installation of a Synchrotron Radiation Beamline Facility at the J. Bennett Johnston Center. Final Report

    SciTech Connect

    Gooden, R.

    2000-03-21

    The Johnston Center presents a unique opportunity for scientists and engineers at southern institutions to initiate and carry out original research using synchrotron radiation ranging from visible light to hard x-rays. The Science and Engineering Alliance proposes to carry out a comprehensive new synchrotron radiation research initiative at CAMD in carefully phased steps of increasing risks. (1) materials research on existing CAMD beam lines and end stations; (2) design, construction and installation of end stations on existing CAMD beam lines, and research with this new instrumentation; (3) design, construction and operation of dedicated synchrotron radiation beam lines that covers the full spectral range of the CAMD storage ring and expanded research in the new facility.

  3. Observations of infragravity motions for reef fringed islands and atolls

    NASA Astrophysics Data System (ADS)

    Becker, J. M.; Merrifield, M. A.; Ford, M.

    2012-12-01

    The frequency of flooding events that affect low lying islands and atolls in the Pacific is expected to increase under current sea level rise projections. Infragravity (IG) motions, with periods ranging from approximately 25 to 400 seconds, are an important component of wave driven flooding events for reef fringed islands and atolls. The IG variability during wave events is analyzed and interpreted dynamically from pressure and current observations at four cross-reef transects in the North Pacific Ocean that include sites in the Republic of the Marshall Islands and Guam. The IG motions are shown to depend upon the spectral properties of the incident wave forcing and reef flat characteristics that include reef flat length (ranging from 100m to 450m at the four sites) and total water level due to setup and tides. A small inundation event at one of the sites is shown to occur due to large shoreline infragravity energy.

  4. Radiological dose assessments of atolls in the Northern Marshall Islands

    SciTech Connect

    Robison, W.L.

    1983-11-01

    Methods and models used to estimate the radiation doses to a returning population of the atolls in the Marshall Islands are presented. In this environment natural processes have acted on source-term radionuclides for nearly 30 years. The data bases developed for the models, and the results of the radiological dose analyses at the various atolls are described. The major radionuclides in order of their contribution to the total estimated doses were /sup 137/Cs, /sup 90/Sr, /sup 239/ /sup 240/Pu, /sup 241/Am, and /sup 60/Co. Exposure pathways in order of their contribution to the estimated doses were: terrestrial food chain, external ..gamma.., marine food chain, inhalation, and cistern water and ground water. 56 references, 13 figures, 16 tables.

  5. Bikini Atoll ionizing radiation survey, May 1985-May 1986

    SciTech Connect

    Shingleton, K.L.; Cate, J.L.; Trent, M.G.; Robison, W.L.

    1987-10-01

    Between 1946 and 1958, the United States conducted 23 nuclear tests at the Bikini Atoll in the Marshall Islands, which resulted in extensive radioactive contamination of a number of islands in the atoll and prevented the timely resettlement of the native population. Although the external dose rates from beta and gamma radiation have been previously determined by aerial survey and a variety of ground measurement techniques, technical constraints limited the assessment of external beta dose rates that result from the /sup 137/Cs and /sup 90/Sr//sup 90/Y contamination on the islands. Now, because of the recent development of very thin thermoluminescent dosimeters (TLDs), the external beta dose rates can be measured. 18 refs., 7 figs., 5 tabs.

  6. Causes of mortality of albatross chicks at Midway Atoll

    USGS Publications Warehouse

    Sileo, L.; Sievert, P.R.; Samuel, M.D.

    1990-01-01

    As part of an investigation of the effect of plastic ingestion on seabirds in Hawaii, we necropsied the carcasses of 137 Laysan albatross (Diomedea immutabilis) chicks from Midway Atoll in the Pacific Ocean during the summer of 1987. Selected tissues were collected for microbiological, parasitological, toxicological or histopathological examinations. Dehydration was the most common cause of death. Lead poisoning, trauma, emaciation (starvation) and trombidiosis were other causes of death; nonfatal nocardiosis and avian pox also were present. There was no evidence that ingested plastic caused mechanical lesions or mortality in 1987, but most of the chicks had considerably less plastic in them than chicks from earlier years. Human activity (lead poisoning and vehicular trauma) caused mortality at Midway Atoll and represented additive mortality for pre-fledgling albatrosses.

  7. Atoll island vulnerability to flooding and inundation revealed by historical reconstruction: Fongafale Islet, Funafuti Atoll, Tuvalu

    NASA Astrophysics Data System (ADS)

    Yamano, Hiroya; Kayanne, Hajime; Yamaguchi, Toru; Kuwahara, Yuji; Yokoki, Hiromune; Shimazaki, Hiroto; Chikamori, Masashi

    2007-06-01

    The reef islands formed on coral atolls are generally small, low, and flat, with elevations of only a few meters. These islands are thus highly vulnerable to elevated sea levels caused by extreme events and global warming. Such vulnerability was recently evidenced at Fongafale Islet, the capital of Tuvalu, when it flooded during accelerated spring high tides possibly related to sea level rise caused by global warming. Many factors, not only environmental but also economic and social, determine the vulnerability of an island to sea level rise. In this study, we used data spanning 108 yrs to reconstruct changes in topography, land use/cover, population, and the distribution of buildings at Fongafale Islet. The results indicate that the vulnerability of Fongafale Islet relates to its original landform characteristics: the central part of the island was formerly dominated by swampland that flooded at high tides. Fongafale Islet experienced greater population in-migration and centralization beginning in the 1970s following the independence of Tuvalu and Kiribati. Migrants were also responding to declines in overseas mining operations and limited options for paid employment. As the population increased, construction took place in vulnerable swampland areas. Our results clearly demonstrate that examinations of global environmental issues should focus on characteristics specific to the region of interest. These characteristics should be specified using historical reconstruction to understand and address the vulnerability of an area to global environmental changes.

  8. Groundwater dynamics of Fongafale Islet, Funafuti Atoll, Tuvalu.

    PubMed

    Nakada, Satoshi; Umezawa, Yu; Taniguchi, Makoto; Yamano, Hiroya

    2012-01-01

    Geoelectric and hydrologic surveys during spring tides revealed the spatiotemporal distribution of groundwater quality produced by tidal forcing in Fongafale Islet, Funafuti Atoll, Tuvalu. The observed low resistivity showed that saline water largely immersed the surficial Holocene aquifer, indicating that there is no thick freshwater lens in Fongafale Islet, unlike in other atoll islands of comparable size. Half of the islet was constructed by reclaiming the original swamp with porous, highly permeable coral blocks; this reclaimed area should not be considered as part of the islet width for calculation of the expected thickness of the freshwater lens. The degree of aquifer salinization depends on the topographic characteristics and the hydrologic controls on the inland propagation of the tidal forcing. Large changes in bulk resistivity and the electrical conductivity of groundwater from wells indicate that periodic salinization in phase with the semidiurnal tides was occurring widely, especially in areas at lower elevation than the high-tide level and in reclaimed areas with high permeability. Thin sheets of nearly fresh and brackish water were observed in the surficial aquifer in areas above the high-tide level and in taro swamps, respectively. The thinness of the brackish and freshwater sheets suggests that the taro swamps and the fresh groundwater resources of the islet are highly vulnerable to salinization from anticipated sea-level rise. An understanding of the inherent geologic and topographic features of an atoll is necessary to evaluate the groundwater resources of the atoll and assess the vulnerability of its water resources to climate change. © 2011, The Author(s). Ground Water © 2011, National Ground Water Association.

  9. Primary productivity and its correlation with rainfall on Aldabra Atoll

    NASA Astrophysics Data System (ADS)

    Shekeine, J.; Turnbull, L. A.; Cherubini, P.; de Jong, R.; Baxter, R.; Hansen, D.; Bunbury, N.; Fleischer-Dogley, F.; Schaepman-Strub, G.

    2015-01-01

    Aldabra Atoll, a UNESCO World Heritage Site since 1982, hosts the world's largest population of giant tortoises. In view of recent rainfall declines in the East African region, it is important to assess the implications of local rainfall trends on the atoll's ecosystem and evaluate potential threats to the food resources of the giant tortoises. However, building an accurate picture of the effects of climate change requires detailed context-specific case-studies, an approach often hindered by data deficiencies in remote areas. Here, we present and analyse a new historical rainfall record of Aldabra atoll together with two potential measures of primary productivity: (1) tree-ring measurements of the deciduous tree species Ochna ciliata and, (2) satellite-derived NDVI (normalized difference vegetation index) data for the period 2001-2012. Rainfall declined by about 6 mm yr-1 in the last four decades, in agreement with general regional declines, and this decline could mostly be attributed to changes in wet-season rainfall. We were unable to cross-date samples of O. ciliata with sufficient precision to deduce long-term patterns of productivity. However, satellite data were used to derive Aldabra's land surface phenology (LSP) for the period 2001-2012 which was then linked to rainfall seasonality. This relationship was strongest in the eastern parts of the atoll (with a time-lag of about six weeks between rainfall changes and LSP responses), an area dominated by deciduous grasses that supports high densities of tortoises. While the seasonality in productivity, as reflected in the satellite record, is correlated with rainfall, we did not find any change in mean rainfall or productivity for the shorter period 2001-2012. The sensitivity of Aldabra's vegetation to rainfall highlights the potential impact of increasing water stress in East Africa on the region's endemic ecosystems.

  10. Assessment of a radioactive waste disposal site at Enewetak Atoll

    SciTech Connect

    Noshkin, V.E.; Robison, W.L.

    1997-07-01

    The 43 nuclear tests conducted at Enewetak Atoll by the United States between 1948 and 1958 produced close-in fallout that contaminated the islands and lagoon of the atoll with radioactive fission and activation products, and unfissioned nuclear fuel. In 1972, the U.S. government announced that it would conduct a cleanup and restoration operation to return the atoll to the Enewetak people. The radiological cleanup began in 1977 and lasted to 1980 and focused on reducing the concentration of the transuranium elements ({sup 238,239,240}Pu and {sup 241}Am = TRU) in soils on some of the islands that might eventually be used for residence or for subsistence agricultural. The cleanup plan called for relocating soil and some other contaminated debris to Runit Island on the eastern perimeter of the Atoll. Some of the contaminated soil was mixed with cement and the mixture placed below the water level in the Cactus Crater that was formed by a nuclear explosion in 1958. The remainder of the contaminated material was mixed with concrete and placed above ground over the crater in the shape of a dome. A concrete cap was constructed over the dome of soil. Concern has been expressed by the people of Enewetak and by others over the possible aquatic impacts from the radionuclides entombed in the crater. Therefore, a surveillance program was started in 1980, in conjunction with other research efforts, to study the radionuclides in samples of fish, groundwater, and lagoon seawater. Our data and conclusions support the findings suggested by the National Academy committee over a decade ago in that any assumption of rapid remobilization of all or any of the dome`s transuranics or other radionuclides is an extreme one. 22 refs., 4 figs., 10 tabs.

  11. Wave and tidal flushing in a near-equatorial mesotidal atoll

    NASA Astrophysics Data System (ADS)

    Costa, Mirella B.; Macedo, Eduardo C.; Valle-Levinson, Arnoldo; Siegle, Eduardo

    2017-03-01

    Most of the atolls found worldwide are under microtidal regimes, and their circulation mechanisms are widely documented and well known. Here, we describe the flushing mechanisms of a small-sized mesotidal atoll, based on water-level, wave and current data obtained during two different periods (total of 60 d). Rocas is the only atoll in the South Atlantic Ocean and is built primarily of coralline algae. Two reef passages connect the atoll lagoon to the ocean. Synchronous current profilers were deployed at the two reef passages, one inside and one outside the atoll, to characterize the influence of tides and waves on the circulation. Results showed that wind waves drove a setup on the exposed side of the atoll and that currents were predominately downwind, causing outflow at both reef passages. Waves breaking on the windward side supplied water to the atoll causing the lagoon water level to rise above ocean water level, driving the outflow. However, unlike microtidal atolls, at Rocas Atoll the water level drops significantly below the reef rim during low tides. This causes the reef rim to act as a barrier to water pumping into the lagoon by waves, resulting in periodic activation of the wave pumping mechanism throughout a tidal cycle. As result, inflow occurs in the wider passage during 27% of each tidal cycle, starting at low tides and reversing direction during mid-flood tide when the water level exceeded approximately 1.6 m (while overtopping the atoll's rim). Our findings show that tides play a direct role in driving circulation on a mesotidal atoll, not only by modulating wave setup but also by determining the duration of wave pumping into the lagoon.

  12. Correlation of sea level falls interpreted from atoll stratigraphy with turbidites in adjacent basins

    SciTech Connect

    Lincoln, J.M. )

    1990-05-01

    Past sea levels can be derived from any atoll subsurface sediments deposited at or near sea level by determining the ages of deposition and correcting the present depths to the sediments for subsidence of the underlying edifice since the times of deposition. A sea level curve constructed by this method consists of discontinuous segments, each corresponding to a period of rising relative sea level and deposition of a discrete sedimentary package. Discontinuities in the sea level curve derived by this method correspond to relative sea level falls and stratigraphic hiatuses in the atoll subsurface. During intervals of relative sea level fall an atoll emerges to become a high limestone island. Sea level may fluctuate several times during a period of atoll emergence to become a high limestone island. Sea level may fluctuate several times during a period of atoll emergence without depositing sediments on top of the atoll. Furthermore, subaerial erosion may remove a substantial part of the depositional record of previous sea level fluctuations. For these reasons the authors must look to the adjacent basins to complement the incomplete record of sea level change recorded beneath atolls. During lowstands of sea level, faunas originally deposited near sea level on an atoll may be eroded and redeposited as turbidites in deep adjacent basins. Three such turbidites penetrated during deep-sea drilling at Sites 462 and 315 in the central Pacific correlate well with a late Tertiary sea level curve based on biostratigraphic ages and {sup 87}Sr/{sup 86}Sr chronostratigraphy for core from Enewetak Atoll in the northern Marshall Islands. Further drilling of the archipelagic aprons adjacent to atolls will improve the sea level history that may be inferred from atoll stratigraphy.

  13. 76 FR 24047 - Palmyra Atoll National Wildlife Refuge, U.S. Pacific Island Territory; Nonnative Rat Eradication...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-29

    ...; Nonnative Rat Eradication Project, Final Environmental Impact Statement AGENCY: Fish and Wildlife Service...), announce the availability of the Palmyra Atoll National Wildlife Refuge (Refuge) nonnative rat eradication... eliminating nonnative rats from Palmyra Atoll (Atoll). We are publishing this notice to inform the public...

  14. 78 FR 12015 - Western Pacific Fisheries; Fishing in the Marianas Trench, Pacific Remote Islands, and Rose Atoll...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-21

    ...; Fishing in the Marianas Trench, Pacific Remote Islands, and Rose Atoll Marine National Monuments AGENCY... fishing in the Marianas Trench, Pacific Remote Islands, and Rose Atoll Marine National Monuments. The...). Proclamation 8337 of January 6, 2009, ``Establishment of the Rose Atoll Marine National Monument'' (74 FR 1577...

  15. Radionuclides in sediments and seawater at Rongelap Atoll

    SciTech Connect

    Noshkin, V.E.; Robison, W.L.; Eagle, R.J.; Brunk, J.L.

    1998-03-01

    The present concentrations and distributions of long-lived, man-made radionuclides in Rongelap Atoll lagoon surface sediments, based on samples collected and analyzed in this report. The radionuclides were associated with debris generated with the 1954 Bravo thermonuclear test at Bikini Atoll. Presently, only {sup 90}Sr and the transuranic radionuclides are found associated with the surface sediments in any quantity. Other radionuclides, including {sup 60}Co and {sup 137} Cs, are virtually absent and have either decayed or migrated from the deposits to the overlying seawater. Present inventories of {sup 241}Am and {sup 249+240}Pu in the surface layer at Rongelap are estimated to be 3% of the respective inventories in surface sediments from Bikini Atoll. There is a continuous slow release of the transuranics from the sediments back to the water column. The inventories will only slowly change with time unless the chemical-physical processes that now regulate this release to the water column are changed or altered.

  16. Marine radioactivity assessment of Mururoa and Fangataufa atolls.

    PubMed

    Povinec, P P; Woodhead, D; Blowers, P; Bonfield, R; Cooper, M; Chen, Q; Dahlgaard, H; Dovlete, C; Fox, V; Froehlich, K; Gastaud, J; Gröning, M; Hamilton, T; Ikeuchi, Y; Kanisch, G; Krüger, A; Kwong, L L; Matthews, M; Morgenstern, U; Mulsow, S; Pettersson, H; Smedley, P; Taylor, B; Taylor, C; Tinker, R

    1999-09-30

    The International Atomic Energy Agency (IAEA) carried out an international project. 'The Study of the Radiological Situation at the Atolls of Mururoa and Fangataufa' with the aim of assessing the present and future radiological situation at the atolls and making recommendations for either monitoring or remedial actions if they are deemed necessary. The paper concentrates on marine radioactivity aspects and gives an estimation of present radionuclide concentrations in water, sediment and biota of the Mururoa and Fangataufa lagoons and the surrounding ocean. The dominant radionuclide in both lagoons is Pu in sediments (the total inventory is approximately 30 TBq). A decline in radionuclide concentrations has been observed in recent years in lagoon water, with the exception of 3H and 90Sr, for which a contribution from underground sources is to be expected. Radionuclide concentrations in biota from the lagoons and the surrounding ocean are low and consistent with previous measurements. The observed radionuclide concentrations in both lagoons imply that no radiological risk exists for hypothetical inhabitants of Mururoa and Fangataufa Atolls.

  17. beta- and gamma-Comparative dose estimates on Enewetak Atoll.

    PubMed

    Crase, K W; Gudiksen, P H; Robison, W L

    1982-05-01

    Enewetak Atoll is one of the Pacific atolls used for atmospheric testing of U.S. nuclear weapons. Beta dose and gamma-ray exposure measurements were made on two islands of the Enewetak Atoll during July-August 1976 to determine the beta and low energy gamma-contribution to the total external radiation doses to the returning Marshallese. Measurements were made at numerous locations with thermoluminescent dosimeters (TLD), pressurized ionization chambers, portable NaI detectors, and thin-window pancake GM probes. Results of the TLD measurements with and without a beta-attenuator indicate that approx. 29% of the total dose rate at 1 m in air is due to beta- or low energy gamma-contribution. The contribution at any particular site, however, is somewhat dependent on ground cover, since a minimal amount of vegetation will reduce it significantly from that over bare soil, but thick stands of vegetation have little effect on any further reductions. Integral 30-yr external shallow dose estimates for future inhabitants were made and compared with external dose estimates of a previous large scale radiological survey (En73). Integral 30-yr shallow external dose estimates are 25-50% higher than whole body estimates. Due to the low penetrating ability of the beta's or low energy gamma's, however, several remedial actions can be taken to reduce the shallow dose contribution to the total external dose.

  18. Calcareous nannofossils and planktic foraminifers from Enewetak Atoll, Western Pacific Ocean: Geologic and geophysical investigations of Enewetak Atoll, Republic of the Marshall Islands. Professional paper

    SciTech Connect

    Bybell, L.M.; Poore, R.Z.

    1991-01-01

    Boring of the carbonate sequence at the northern end of Enewetak Atoll, Republic of the Marshall Islands, was conducted in 1985, as part of the Pacific Enewetak Atoll Crater Exploration (PEACE) Program. The overall goal of the program was to characterize physical effects of large-scale nuclear blasts, which were conducted in the early 1950's, on the sediments of the atoll. In the report the authors document the occurrences of stratigraphically diagnostic planktic microfossils in samples from Enewetak (generally referred to as core) and outline the rationale for incorporating all available diagnostic planktic assemblages into a composite sequence that was used to date the Enewetak benthic zonation.

  19. 33 CFR 334.1440 - Pacific Ocean at Kwajalein Atoll, Marshall Islands; missile testing area.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Pacific Ocean at Kwajalein Atoll, Marshall Islands; missile testing area. 334.1440 Section 334.1440 Navigation and Navigable Waters CORPS OF....1440 Pacific Ocean at Kwajalein Atoll, Marshall Islands; missile testing area. (a) The warning area...

  20. 33 CFR 334.1440 - Pacific Ocean at Kwajalein Atoll, Marshall Islands; missile testing area.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Pacific Ocean at Kwajalein Atoll, Marshall Islands; missile testing area. 334.1440 Section 334.1440 Navigation and Navigable Waters CORPS OF....1440 Pacific Ocean at Kwajalein Atoll, Marshall Islands; missile testing area. (a) The warning area...

  1. 33 CFR 334.1440 - Pacific Ocean at Kwajalein Atoll, Marshall Islands; missile testing area.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Pacific Ocean at Kwajalein Atoll, Marshall Islands; missile testing area. 334.1440 Section 334.1440 Navigation and Navigable Waters CORPS OF....1440 Pacific Ocean at Kwajalein Atoll, Marshall Islands; missile testing area. (a) The warning area...

  2. 33 CFR 334.1440 - Pacific Ocean at Kwajalein Atoll, Marshall Islands; missile testing area.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Pacific Ocean at Kwajalein Atoll, Marshall Islands; missile testing area. 334.1440 Section 334.1440 Navigation and Navigable Waters CORPS OF....1440 Pacific Ocean at Kwajalein Atoll, Marshall Islands; missile testing area. (a) The warning area...

  3. 33 CFR 334.1440 - Pacific Ocean at Kwajalein Atoll, Marshall Islands; missile testing area.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Pacific Ocean at Kwajalein Atoll, Marshall Islands; missile testing area. 334.1440 Section 334.1440 Navigation and Navigable Waters CORPS OF....1440 Pacific Ocean at Kwajalein Atoll, Marshall Islands; missile testing area. (a) The warning area...

  4. Clean Up, Rehabilitation, Resettlement of Enewetak Atoll -Marshall Islands. Volume III.

    DTIC Science & Technology

    The documentation is a summary of the Draft Environmental Impact Statement (DEIS) for a proposed project to clean up the Atoll of Enewetak and...resettle the Enewetak people on the Atoll . The summary has been prepared specifically for translation into the language of the Enewetak people.

  5. 19 CFR 7.2 - Insular possessions of the United States other than Puerto Rico.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... possessions are the U.S. Virgin Islands, Guam, American Samoa, Wake Island, Midway Islands, and Johnston Atoll...) Importations into Guam, American Samoa, Wake Island, Midway Islands, Johnston Atoll, and the Commonwealth of... no customs authority on Johnston Atoll, which is under the operational control of the Defense...

  6. 19 CFR 7.2 - Insular possessions of the United States other than Puerto Rico.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... possessions are the U.S. Virgin Islands, Guam, American Samoa, Wake Island, Midway Islands, and Johnston Atoll...) Importations into Guam, American Samoa, Wake Island, Midway Islands, Johnston Atoll, and the Commonwealth of... no customs authority on Johnston Atoll, which is under the operational control of the Defense...

  7. 19 CFR 7.2 - Insular possessions of the United States other than Puerto Rico.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... possessions are the U.S. Virgin Islands, Guam, American Samoa, Wake Island, Midway Islands, and Johnston Atoll...) Importations into Guam, American Samoa, Wake Island, Midway Islands, Johnston Atoll, and the Commonwealth of... no customs authority on Johnston Atoll, which is under the operational control of the Defense...

  8. 19 CFR 7.2 - Insular possessions of the United States other than Puerto Rico.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... possessions are the U.S. Virgin Islands, Guam, American Samoa, Wake Island, Midway Islands, and Johnston Atoll...) Importations into Guam, American Samoa, Wake Island, Midway Islands, Johnston Atoll, and the Commonwealth of... no customs authority on Johnston Atoll, which is under the operational control of the Defense...

  9. 19 CFR 7.2 - Insular possessions of the United States other than Puerto Rico.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... possessions are the U.S. Virgin Islands, Guam, American Samoa, Wake Island, Midway Islands, and Johnston Atoll...) Importations into Guam, American Samoa, Wake Island, Midway Islands, Johnston Atoll, and the Commonwealth of... no customs authority on Johnston Atoll, which is under the operational control of the Defense...

  10. Nutrient concentrations and primary productivity at the Peros Banhos and Salomon atolls in the Chagos Archipelago

    NASA Astrophysics Data System (ADS)

    Rayner, R. F.; Drew, E. A.

    1984-02-01

    Coral atolls are areas of high biological productivity even though they are usually located in regions of the tropical ocean characterized by low primary production and extremely low levels of vital dissolved nutrient materials. Recent studies have indicated the possible importance of in situ dinitrogen fixation on shallow reef flats in supplementing low oceanic nitrate levels and thus contributing to the maintenance of high reef productivity. Variations in the structure of atolls may have a direct bearing on the accumulation of fixed nitrogen and other nutrient materials, and consequently on lagoonal and reefal primary productivity. This paper investigates the effect of differing atoll configurations by comparing neighbouring, but structurally dissimilar, mid-ocean atolls. The findings are discussed in terms of ecosystem function and possible influences on the structural evolution of atolls.

  11. Helium-3 inside atoll barrier reef interstitial water: A clue for geothermal endo-upwelling

    SciTech Connect

    Rougerie, F. ); Andrie, C. ); Jean-Baptiste, P.

    1991-01-01

    Interstitial waters from boreholes in the reef conglomerate of Tikehau atoll (S.W. Pacific) contain positive anomalous concentrations of dissolved inorganic nutrients compared to adjacent oceanic and lagoonal waters. These anomalies have been interpreted by geothermal circulation of deep oceanic waters penetrating the porous reef carbonates and ascending through the atoll flanks by thermo-convective advection as already proposed for other atolls. The authors present here a new strong evidence of this geothermal circulation inside atoll reefs from the record of helium-3 anomalies in borehole waters of Tikehau atoll. These results bear directly on three controversial aspects of reef history: the efficiency of thermal energy for circulation of reef pore waters, the sources of nutrients to support the net productivity of reef ecosystems, the early diagenesis of reef foundation carbonates.

  12. Miocene to Present Sea Level and the Origin of Modern Rimmed Atoll Morphology

    NASA Astrophysics Data System (ADS)

    Toomey, M.; Perron, J. T.; Raymo, M. E.; Ashton, A. D.

    2014-12-01

    Rising sea-level over the next century will reshape our coastlines and make low-lying islands more vulnerable to extreme events. Atolls could potentially provide unique geologic records from periods of high sea level analogous to those we might experience over the coming centuries. However, sea-level records from atolls have been largely overlooked, in part because the processes that shape coral reef and atoll form are often complex and, in many cases, remain unexplored. Darwin's canonical model, which proposes an evolution from fringing reef to barrier reef to atoll as an ocean island ages and subsides, cannot explain the stratigraphy or morphology of many island reefs. We will present a study that combines a numerical model of reef development with existing stratigraphic records from Pacific atolls. The model, driven by sea level, simulates the evolution of atoll morphology using parameterizations of coral growth, rim derived sediment and in situ production, dissolution, and subsidence. We use it to solve for late-Miocene to present sea level by iteratively changing the ice volume and deep-ocean temperature corrections for converting deep-ocean, benthic, δ18O to sea level and finding the best-fit between the model output and corelog stratigraphy from Enewetak Atoll. We then compare lagoon depths produced by the model for different island sizes and dissolution rates (but the same subsidence and sediment production rates) to an independent dataset of real-world observations from the Marshall, Gilbert and Caroline Island chains. Our model results suggest that a period of sustained low sea level occurred during the late Miocene before rising above present moving into the Pliocene. We propose that it was atoll exposure and enhanced lagoon dissolution during the subsequent sea-level fall since the late Pliocene, ~2.7 Ma - not crustal subsidence, as Darwin's canonical model of atoll evolution presumes - that likely drove the development of modern rimmed atoll

  13. Assessment of circulation and inter-basin transport in the Salish Sea including Johnstone Strait and Discovery Islands pathways

    SciTech Connect

    Khangaonkar, Tarang; Long, Wen; Xu, Wenwei

    2017-01-01

    The Salish Sea consisting of Puget Sound and Georgia Basin in U.S and Canadian waters has been the subject of several independent data collection and modeling studies. However, these interconnected basins and their hydrodynamic interactions have not received attention as a contiguous unit. The Strait of Juan de Fuca is the primary pathway through which Pacific Ocean water enters the Salish Sea but the role played by Johnstone Strait and the complex channels northeast of Vancouver Island, connecting the Salish Sea and the Pacific Ocean, on overall Salish Sea circulation has not been characterized. In this paper we present a modeling-based assessment of the two-layer circulation and transport through the multiple interconnected sub-basins within the Salish Sea including the effect of exchange via Johnstone Strait and Discovery Islands. The Salish Sea Model previously developed using the finite volume community ocean model (FVCOM) was expanded over the continental shelf for this assessment encircling Vancouver Island, including Discovery Islands, Johnstone Strait, Broughton Archipelago and the associated waterways. A computational technique was developed to allow summation of volume fluxes across arbitrary transects through unstructured finite volume cells. Tidally averaged volume fluxes were computed at multiple transects. The results were used to validate the classic model of Circulation in Embracing Sills for Puget Sound and to provide quantitative estimates of the lateral distribution of tidally averaged transport through the system. Sensitivity tests with and without exchanges through Johnstone Strait demonstrate that it is a pathway for Georgia Basin runoff and Fraser River water to exit the Salish Sea and for Pacific Ocean inflow. However the relative impact of this exchange on circulation and flushing in Puget Sound Basin is small.

  14. Assessment of circulation and inter-basin transport in the Salish Sea including Johnstone Strait and Discovery Islands pathways

    NASA Astrophysics Data System (ADS)

    Khangaonkar, Tarang; Long, Wen; Xu, Wenwei

    2017-01-01

    The Salish Sea consisting of Puget Sound and Georgia Basin in U.S and Canadian waters has been the subject of several independent data collection and modeling studies. However, these interconnected basins and their hydrodynamic interactions have not received attention as a contiguous unit. The Strait of Juan de Fuca is the primary pathway through which Pacific Ocean water enters the Salish Sea but the role played by Johnstone Strait and the complex channels northeast of Vancouver Island, connecting the Salish Sea and the Pacific Ocean, on overall Salish Sea circulation has not been characterized. In this paper we present a modeling-based assessment of the two-layer circulation and transport through the multiple interconnected sub-basins within the Salish Sea including the effect of exchange via Johnstone Strait and Discovery Islands. The Salish Sea Model previously developed using the finite volume community ocean model (FVCOM) was expanded over the continental shelf for this assessment encircling Vancouver Island, including Discovery Islands, Johnstone Strait, Broughton Archipelago and the associated waterways. A computational technique was developed to allow summation of volume fluxes across arbitrary transects through unstructured finite volume cells. Tidally averaged volume fluxes were computed at multiple transects. The results were used to validate the classic model of Circulation in Embracing Sills for Puget Sound and to provide quantitative estimates of the lateral distribution of tidally averaged transport through the system. Sensitivity tests with and without exchanges through Johnstone Strait demonstrate that it is a pathway for Georgia Basin runoff and Fraser River water to exit the Salish Sea and for Pacific Ocean inflow. However the relative impact of this exchange on circulation and flushing in Puget Sound Basin is small.

  15. Lifetime Risk of Symptomatic Hand Osteoarthritis: The Johnston County Osteoarthritis Project.

    PubMed

    Qin, Jin; Barbour, Kamil E; Murphy, Louise B; Nelson, Amanda E; Schwartz, Todd A; Helmick, Charles G; Allen, Kelli D; Renner, Jordan B; Baker, Nancy A; Jordan, Joanne M

    2017-06-01

    Symptomatic hand osteoarthritis (OA) is a common condition that affects hand strength and function, and causes disability in activities of daily living. Prior studies have estimated that the lifetime risk of symptomatic knee OA is 45% and that of hip OA is 25%. The objective of the present study was to estimate the overall lifetime risk of symptomatic hand OA, and the stratified lifetime risk according to potential risk factors. Data were obtained from 2,218 adult subjects (ages ≥45 years) in the Johnston County Osteoarthritis Project, a population-based prospective cohort study among residents of Johnston County, North Carolina. Data for the present study were collected from 2 of the follow-up cycles (1999-2004 and 2005-2010). Symptomatic hand OA was defined as the presence of both self-reported symptoms and radiographic OA in the same hand. Lifetime risk, defined as the proportion of the population who will develop symptomatic hand OA in at least 1 hand by age 85 years, was estimated from models using generalized estimating equations. Overall, the lifetime risk of symptomatic hand OA was 39.8% (95% confidence interval [95% CI] 34.4-45.3%). In this population, nearly 1 in 2 women (47.2%, 95% CI 40.6-53.9%) had an estimated lifetime risk of developing symptomatic hand OA by age 85 years, compared with 1 in 4 men (24.6%, 95% CI 19.5-30.5%). Race-specific symptomatic hand OA risk estimates were 41.4% (95% CI 35.5-47.6%) among whites and 29.2% (95% CI 20.5-39.7%) among African Americans. The lifetime risk of symptomatic hand OA among individuals with obesity (47.1%, 95% CI 37.8-56.7%) was 11 percentage points higher than that in individuals without obesity (36.1%, 95% CI 29.7-42.9%). These findings demonstrate the substantial burden of symptomatic hand OA overall and in sociodemographic and clinical subgroups. Increased use of public health and clinical interventions is needed to address its impact. © 2017, American College of Rheumatology.

  16. Population pressure on coral atolls: trends and approaching limits.

    PubMed

    Rapaport, M

    1990-09-01

    Trends and approaching limits of population pressure on coral atolls is discussed by examining the atoll environment in terms of the physical geography, the production systems, and resource distribution. Atoll populations are grouped as dependent and independent, and demographic trends in population growth, migraiton, urbanization, and political dependency are reviewed. Examination of the carrying capacity includes a dynamic model, the influences of the West, and philopsophical considerations. The carrying capacity is the "maximal population supportable in a given area". Traditional models are criticized because of a lack in accounting for external linkages. The proposed model is dynamic and considers perceived needs and overseas linkages. It also explains regional disparities in population distribution, and provides a continuing model for population movement from outer islands to district centers and mainland areas. Because of increased expectations and perceived needs, there is a lower carrying capacity for outlying areas, and expanded capacity in district centers. This leads to urbanization, emigration, and carrying capacity overshot in regional and mainland areas. Policy intervention is necessary at the regional and island community level. Atolls, which are islands surrounding deep lagoons, exist in archipelagoes across the oceans, and are rich in aquatic life. The balance in this small land area with a vulnerable ecosystem may be easily disturbed by scarce water supplies, barren soils, rising sea levels in the future, hurricanes, and tsunamis. Traditionally, fisheries and horticulture (pit-taro, coconuts, and breadfruit) have sustained populations, but modern influences such as blasting, reef mining, new industrial technologies, population pressure, and urbanization threaten the balance. Population pressure, which has lead to pollution, epidemics, malnutrition, crime, social disintegration, and foreign dependence, is evidenced in the areas of Tuvalu, Kiribati

  17. Assessment of a radioactive waste disposal site at Enewetak Atoll.

    PubMed

    Noshkin, V E; Robison, W L

    1997-07-01

    The 43 nuclear tests conducted at Enewetak Atoll by the United States between 1948 and 1958 produced close-in fallout that contaminated the islands and lagoon of the atoll with radioactive fission and activation products, and unfissioned nuclear fuel. In 1972, the U.S. government announced that it would conduct a cleanup and restoration operation to return the atoll to the Enewetak people. The radiological cleanup began in 1977 and lasted to 1980 and focused on reducing the concentration of the transuranium elements (238,239,240Pu and 241Am = TRU) in soils on some of the islands that might eventually be used for residence or for subsistence agricultural. The cleanup plan called for relocating soil and some other contaminated debris to Runit Island on the eastern perimeter of the Atoll. Some of the contaminated soil was mixed with cement and the mixture placed below the water level in the Cactus Crater that was formed by a nuclear explosion in 1958. The remainder of the contaminated material was mixed with concrete and placed above ground over the crater in the shape of a dome. A concrete cap was constructed over the dome of soil. Concern has been expressed by the people of Enewetak and by others over the possible aquatic impacts from the radionuclides entombed in the crater. A National Academy of Sciences committee examined the dome and concluded that the containment structure and its contents present no credible health hazard to the people of Enewetak, either now or in the future. The committee suggested that "at least part of the radioactivity contained in the structure is available for transport to the groundwater and subsequently to the lagoon and it is important to determine whether this pathway may be a significant one." Therefore, a surveillance program was started in 1980, in conjunction with other research efforts, to study the radionuclides in samples of fish, groundwater, and lagoon seawater. Our data and conclusions support the findings suggested by the

  18. Geothermal convection: a mechanism for dolomitization at Enewetak Atoll?

    USGS Publications Warehouse

    Wilson, A.M.; Sanford, W.; Whitaker, F.; Smart, P.

    2000-01-01

    Geothermal convection in carbonate platforms could drive massive dolomitization by supplying mass transport of magnesium over long periods and at temperatures high enough to overcome kinetic limitations. Reactive-transport simulations based on Enewetak Atoll show dolomitization in a thin band at a permeability contrast near the base of the platform, which is consistent with field observations of dolomitized Eocene deposits. Dolomitization is predicted at approximately 6% per My at temperatures of 45–60°C, and complete dolomitization could be accomplished in ∼16 My. Calcium enrichment of pore fluids and upward transport of these fluids is established early, prior to 30 ky.

  19. Geoarchaeology of a 'drowning' island: geomorphologic formation and prehistoric human habitation of Funafuti Atoll, Tuvalu

    NASA Astrophysics Data System (ADS)

    Yamaguchi, T.; Kobayashi, R.

    2012-12-01

    There seem to be a variety to vulnerability of atolls. In fact our archaeological investigations of Majuro in Marshall and Funafuti in Tuvalu revealed diverse duration of human settlement histories. The most reliable charcoal ages for earliest human habitation on Oceanic atolls were obtained from Majuro Atoll, which date back to 1800 - 2000 yr. BP, but radiocarbon ages of charcoal samples retrieved from Funafuti and Vaitupu suggest that Tuvalu were inhabited around ca. 500 yr. BP. It should be helpful to examine geomorphic formation of each atoll islet in considering this temporal difference of human settlement histories. During the mid-Holocene period, the paleoreef had grown up to reach the highstand sea level over the bedrock of Pleistocene limestone. The emergence of the Holocene reef is estimated around 2000 yr. BP in the central Pacific, which is viewed as a trigger of depositional process of atoll islets. There is, however, the possibility that the process was not uniform and sedimentation of foraminiferal sand and coral shingle was affected with more local conditions. Several results of our geoarchaeological excavations in Fongafale, Funafuti Atoll, would be related with this topic. Synthesizing them with the late 18th century's topographic information reported by the Royal Society of London, I then discuss a tentative scenario of geomorphologic formation and prehistoric human settlement of Fongafale. The diversity of human settlement histories could be an indicator of the relative vulnerability of atoll islets.

  20. Holocene Vegetation and Paleoclimatic and Paleomagnetic History from Lake Johnston, Tasmania

    NASA Astrophysics Data System (ADS)

    Anker, Sharon A.; Colhoun, Eric A.; Barton, Charles E.; Peterson, Mike; Barbetti, Mike

    2001-09-01

    Lake Johnston cirque contains some of the best subalpine rainforest in Tasmania. Pollen from the sediments shows Lagarostrobos franklinii, which presently reaches 1040 m, may be a glacial relict. Nothofagus cunninghamii-Nothofagus gunnii subalpine rainforest developed between 9000 and 6000 14C yr B.P., with a maximum at 8700 14C yr B.P. After 6000 14C yr B.P. Nothofagus gunnii became more important, and from 3600 14C yr B.P. sclerophyll and heath components increased. Partial burning of the catchment occurred periodically. Early Holocene climate was warmer and wetter than late Holocene climate. The vegetation and climate changes are similar to those recorded from western South Island New Zealand and Chile. Radiocarbon dates give a sedimentation rate of 0.43 mm/yr. Cores are correlated by magnetic susceptibility. Magnetic ages are assigned by matching with the 14C-dated secular variation master curve for southeastern Australia. Magnetic ages are consistent with the 14C chronology when the former are adjusted by 350 years.

  1. CHAWS user's guide: System description and standard operating procedures, Johnston Island JCAD Facility

    SciTech Connect

    Martins, S.A.; Shinn, J.H.

    1990-07-01

    The Chemical Hazard Warning System (CHAWS) is designed to collect meteorological data and to display, in real time, the dispersion of hazardous chemicals that may result from an accidental release. Meteorological sensors have been placed strategically around the Johnston Island JCAD Facility and are used to calculate direction and hazard distance for the release. Based on these data, arrows depicting the release direction and distance traveled are graphically displayed on a computer screen showing a site map of the facility. The objectives of CHAWS are as follows: to determine the trajectory of the center of the mass of released material from the measured wind field; to calculate the dispersion of the released material based on the measured lateral turbulence intensity (sigma theta); to determine the height of the mixing zone by measurement of the inversion height and wind profiles up to an altitude of about 1 km at sites that have SODAR units installed; to archive meteorological data for potential use in climatological descriptions for emergency planning; to archive air-quality data for preparation of compliance reports; to provide access to the data for near real time hazard analysis purposes.

  2. CHAWS user`s guide: System description and standard operating procedures, Johnston Island JCAD Facility

    SciTech Connect

    Martins, S.A.; Shinn, J.H.

    1990-07-01

    The Chemical Hazard Warning System (CHAWS) is designed to collect meteorological data and to display, in real time, the dispersion of hazardous chemicals that may result from an accidental release. Meteorological sensors have been placed strategically around the Johnston Island JCAD Facility and are used to calculate direction and hazard distance for the release. Based on these data, arrows depicting the release direction and distance traveled are graphically displayed on a computer screen showing a site map of the facility. The objectives of CHAWS are as follows: to determine the trajectory of the center of the mass of released material from the measured wind field; to calculate the dispersion of the released material based on the measured lateral turbulence intensity (sigma theta); to determine the height of the mixing zone by measurement of the inversion height and wind profiles up to an altitude of about 1 km at sites that have SODAR units installed; to archive meteorological data for potential use in climatological descriptions for emergency planning; to archive air-quality data for preparation of compliance reports; to provide access to the data for near real time hazard analysis purposes.

  3. A review of the subfamily Picobiinae Johnston and Kethley, 1973 (Acariformes: Prostigmata: Syringophilidae).

    PubMed

    Skoracki, Maciej; Sikora, Bozena; Spicer, Greg S

    2016-05-19

    The fauna of quill mites of the subfamily Picobiinae Johnston and Kethley, 1973 (Acariformes: Cheyletoidea: Syringophilidae) is comprehensively revised. All of 78 known species, which are grouped into 11 genera, are examined and diagnosed or redescribed. Data on picobiine hosts and distribution are summarized, including new host and locality records. The following new species are described: Charadriineopicobia apricaria sp. nov. ex Pluvialis apricaria (Linnaeus) (Charadriiformes: Charadriidae) from France, Neopicobia pari sp. nov. ex Periparus venustulus Swinhoe (type host) (Passeriformes: Paridae) from China, Parus major Linnaeus (Paridae) from Macedonia and Finland, and Poecile varius Temminck and Schlegel (Paridae) from Japan, Picobia magellani sp. nov. ex Scytalopus magellanicus (Gmelin) (Passeriformes: Rhinocryptidae) from Colombia, Picobia lonchura sp. nov. ex Lonchura leucogastra (Blyth) (Passeriformes: Estrildidae) from Indonesia, Picobia makoli sp. nov. ex Xiphocolaptes promeropirhynchus (Lesson) (Passeriformes: Furnariidae) from Colombia. The species Picobia polonica Skoracki, Magowski and Dabert, 2001 syn. nov. is a junior synonym of C. khulkhaskhani Kivganov and Sharafat, 1995. The following new combinations are proposed: Neopicobia ictericus (Skoracki and Glowska, 2010) comb. nov., Rafapicobia brotogeris (Fain, Bochkov and Mironov, 2000) comb. nov., and Rafapicobia ramphastos (Fain, Bochkov and Mironov, 2000) comb. nov. Keys to the all picobiine genera and species are presented, along with a check-list of picobiine species and their hosts.

  4. Comparison of space analysis performed on plaster vs. digital dental casts applying Tanaka and Johnston's equation.

    PubMed

    Sanches, Júlia Olien; dos Santos-Pinto, Lourdes Aparecida Martins; dos Santos-Pinto, Ary; Grehs, Betina; Jeremias, Fabiano

    2013-01-01

    The purpose of this study was to compare dental size measurements, their reproducibility and the application of Tanaka and Johnston regression equation in predicting the size of canines and premolars on plaster and digital dental casts. Thirty plaster casts were scanned and digitized. Mesiodistal measurements of the teeth were then performed with a digital caliper on the plaster and digital casts using O3d software system (Widialabs©).The sum of the sizes of the lower incisors was used to obtain predictive values of the sizes of the premolars and canines using the regression equation, and these values were compared with the actual sizes of the teeth. The data were statistically analyzed by applying to the results Pearson's correlation test, Dahlberg's formula, paired t-test and analysis of variance (p < 0.05). Excellent intraexaminer agreement was observed in the measurements performed on both dental casts. No random error was present in the measurements obtained with the caliper and systematic error (bias) was more frequent in the digital casts. Space prediction obtained by applying the regression equation was greater than the sum of the canines and premolars on the plaster and digital casts. Despite an adequate reproducibility of the measurements performed on both casts, most measurements on the digital casts were higher than those on the plaster casts. The predicted space was overestimated in both models and significantly higher in the digital casts.

  5. Hydrogeology and management of freshwater lenses on atoll islands: Review of current knowledge and research needs

    NASA Astrophysics Data System (ADS)

    Werner, Adrian D.; Sharp, Hannah K.; Galvis, Sandra C.; Post, Vincent E. A.; Sinclair, Peter

    2017-08-01

    On atoll islands, fresh groundwater occurs as a buoyant lens-shaped body surrounded by saltwater derived from the sea, forming the main freshwater source for many island communities. A review of the state of knowledge of atoll island groundwater is overdue given their susceptibility to adverse impacts, and the task to address water access and sanitation issues within the United Nations' Sustainable Development Goals framework before the year 2030. In this article, we review available literature to summarise the key processes, investigation techniques and management approaches of atoll island groundwater systems. Over fifty years of investigation has led to important advancements in the understanding of atoll hydrogeology, but a paucity of hydrogeological data persists on all but a small number of atoll islands. We find that the combined effects of buoyancy forces, complex geology, tides, episodic ocean events, strong climatic variability and human impacts create highly dynamic fresh groundwater lenses. Methods used to quantify freshwater availability range from simple empirical relationships to three-dimensional density-dependent models. Generic atoll island numerical models have proven popular in trying to unravel the individual factors controlling fresh groundwater lens behaviour. Major challenges face the inhabitants and custodians of atoll island aquifers, with rising anthropogenic stresses compounded by the threats of climate variability and change, sea-level rise, and some atolls already extracting freshwater at or above sustainability limits. We find that the study of atoll groundwater systems remains a critical area for further research effort to address persistent knowledge gaps, which lead to high uncertainties in water security issues for both island residents and surrounding environs.

  6. Cretaceous karst guyots: New evidence for inheritance of atoll morphology from subaerial erosional terrain

    NASA Astrophysics Data System (ADS)

    Winterer, Edward L.

    1998-01-01

    Data from recent surveys and drilling suggest that carbonate platforms over a wide region of the oceanic western Pacific became emergent by amounts of 100 200 m during late Albian time, ca. 100 Ma. The resulting erosional landscapes, now modified by differential compaction over the buried volcanic basement hills, included central basins surrounded by perimeter rims, sinkhole-like depressions, and perimeter benches interpreted as wave-cut terraces. Resubmergence resulted in the sealing of atoll-like erosional topography by pelagic sediments. These Cretaceous proto-atolls, now guyots, provide evidence that ancient as well as modern atolls inherit their form mainly from subaerial landscapes.

  7. Baseline for beached marine debris on Sand Island, Midway Atoll.

    PubMed

    Ribic, Christine A; Sheavly, Seba B; Klavitter, John

    2012-08-01

    Baseline measurements were made of the amount and weight of beached marine debris on Sand Island, Midway Atoll, June 2008-July 2010. On 23 surveys, 32,696 total debris objects (identifiable items and pieces) were collected; total weight was 740.4 kg. Seventy-two percent of the total was pieces; 91% of the pieces were made of plastic materials. Pieces were composed primarily of polyethylene and polypropylene. Identifiable items were 28% of the total; 88% of the identifiable items were in the fishing/aquaculture/shipping-related and beverage/household products-related categories. Identifiable items were lowest during April-August, while pieces were at their lowest during June-August. Sites facing the North Pacific Gyre received the most debris and proportionately more pieces. More debris tended to be found on Sand Island when the Subtropical Convergence Zone was closer to the Atoll. This information can be used for potential mitigation and to understand the impacts of large-scale events such as the 2011 Japanese tsunami.

  8. Plutonium and americium behavior in coral atoll environments

    SciTech Connect

    Noshkin, V.E.; Wong, K.M.; Jokela, T.A.; Brunk, J.L.; Eagle, R.J.

    1984-02-01

    Inventories of /sup 239 +240/Pu and /sup 241/Am greatly in excess of global fallout levels persist in the benthic environments of Bikini and Enewetak Atolls. Quantities of /sup 239 +240/Pu and lesser amounts of /sup 241/Am are continuously mobilizing from these sedimentary reservoirs. The amount of /sup 239 +240/Pu mobilized to solution at any time represents 0.08 to 0.09% of the sediment inventories to a depth of 16 cm. The mobilized /sup 239 +240/Pu has solute-like characteristics and different valence states coexist in solution - the largest fraction of the soluble plutonium is in an oxidized form (+V,VI). The adsorption of plutonium to sediments is not completely reversible because of changes that occur in the relative amounts of the mixed oxidation states in solution with time. Further, any characteristics of /sup 239 +240/Pu described at one location may not necessarily be relevant in describing its behavior elsewhere following mobilization and migration. The relative amounts of /sup 241/Am to /sup 239 +240/Pu in the sedimentary deposits at Enewetak and Bikini may be altered in future years because of mobilization and radiological decay. Mobilization of /sup 239 +240/Pu is not a process unique to these atolls, and quantities in solution derived from sedimentary deposits can be found at other global sites. These studies in the equatorial Pacific have significance in assessing the long-term behavior of the transuranics in any marine environment. 22 references, 1 figure, 13 tables.

  9. Electromagnetic methods for mapping freshwater lenses on Micronesian atoll islands

    USGS Publications Warehouse

    Anthony, S.S.

    1992-01-01

    The overall shape of freshwater lenses can be determined by applying electromagnetic methods and inverse layered-earth modeling to the mapping of atoll island freshwater lenses. Conductivity profiles were run across the width of the inhabited islands at Mwoakilloa, Pingelap, and Sapwuahfik atolls of the Pohnpei State, Federated States of Micronesia using a dual-loop, frequency-domain, electromagnetic profiling system. Six values of apparent conductivity were recorded at each sounding station and were used to interpret layer conductivities and/or thicknesses. A three-layer model that includes the unsaturated, freshwater, and saltwater zones was used to simulate apparent-conductivity data measured in the field. Interpreted results were compared with chloride-concentration data from monitoring wells and indicate that the interface between freshwater and saltwater layers, defined from electromagnetic data, is located in the upper part of the transition zone, where the chloride-concentration profile shows a rapid increase with depth. The electromagnetic method can be used to interpret the thickness of the freshwater between monitoring wells, but can not be used to interpret the thickness of freshwater from monitoring wells to the margin of an island. ?? 1992.

  10. Electromagnetic methods for mapping freshwater lenses on Micronesian atoll islands

    NASA Astrophysics Data System (ADS)

    Anthony, Stephen S.

    1992-08-01

    The overall shape of freshwater lenses can be determined by applying electromagnetic methods and inverse layered-earth modeling to the mapping of atoll island freshwater lenses. Conductivity profiles were run across the width of the inhabited islands at Mwoakilloa, Pingelap, and Sapwuahfik atolls of the Pohnpei State, Federated States of Micronesia using a dual-loop, frequency-domain, electromagnetic profiling system. Six values of apparent conductivity were recorded at each sounding station and were used to interpret layer conductivities and/or thicknesses. A three-layer model that includes the unsaturated, freshwater, and saltwater zones was used to simulate apparent-conductivity data measured in the field. Interpreted results were compared with chloride-concentration data from monitoring wells and indicate that the interface between freshwater and saltwater layers, defined from electromagnetic data, is located in the upper part of the transition zone, where the chloride-concentration profile shows a rapid increase with depth. The electromagnetic method can be used to interpret the thickness of the freshwater between monitoring wells, but can not be used to interpret the thickness of freshwater from monitoring wells to the margin of an island.

  11. 40 CFR 1.7 - Location of principal offices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... territories of Baker Island, Howland Island, Jarvis Island, Johnston Atoll, Kingman Reef, Midway Atoll, Palmyra Atoll, and Wake Islands; and certain U.S. Government activities in the freely associated states...

  12. 40 CFR 1.7 - Location of principal offices.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... territories of Baker Island, Howland Island, Jarvis Island, Johnston Atoll, Kingman Reef, Midway Atoll, Palmyra Atoll, and Wake Islands; and certain U.S. Government activities in the freely associated states...

  13. 40 CFR 62.10 - Submission to Administrator.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... territories of Baker Island, Howland Island, Jarvis Island, Johnston Atoll, Kingman Reef, Midway Atoll, Palmyra Atoll, and Wake Islands; and certain U.S. Government activities in the freely associated states...

  14. 40 CFR 1.7 - Location of principal offices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Northern Mariana Islands; the territories of Baker Island, Howland Island, Jarvis Island, Johnston Atoll, Kingman Reef, Midway Atoll, Palmyra Atoll, and Wake Islands; and certain U.S. Government activities in...

  15. 40 CFR 62.10 - Submission to Administrator.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Islands; the territories of Baker Island, Howland Island, Jarvis Island, Johnston Atoll, Kingman Reef, Midway Atoll, Palmyra Atoll, and Wake Islands; and certain U.S. Government activities in the...

  16. 40 CFR 1.7 - Location of principal offices.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... territories of Baker Island, Howland Island, Jarvis Island, Johnston Atoll, Kingman Reef, Midway Atoll, Palmyra Atoll, and Wake Islands; and certain U.S. Government activities in the freely associated states...

  17. Aerial radiological and photographic survey of eleven atolls and two islands within the Northern Marshall Islands. Dates of surveys, July-November 1978

    SciTech Connect

    Not Available

    1981-06-01

    An aerial radiological survey was conducted over eleven atolls and two islands within the northern Marshall Islands between September and November 1978. This survey was part of a comprehensive radiological survey, which included extensive terrestrial and marine sampling, to determine possible residual contamination which might remain as a result of the United States nuclear testing program conducted at Bikini Enewetak Atolls between 1946 and 1958. A similar survey was conducted at Enewetak Atoll in 1972. The present survey covered those atolls known to have received direct fallout from the Bravo event, conducted in March 1954 at Bikini Atoll. These included Bikini, Rongelap, Rongerik, Ailinginae, Bikar, Taka, and Utirik Atolls. In addition, several atolls and islands which might have been at the fringes of the Bravo fallout were also surveyed, including Likiep and Ailuk Atolls, Jemo and Mejit Islands, and Wotho Atoll. Ujelang Atoll, which lies approximately 200 km southwest of Enewetak, was also surveyed. Island-averaged terrestrial exposure rates in the range of 30 to 50 ..mu..R/h were observed over parts of Bikini Atoll, including Bikini Island, and over the northern part of Rongelap Atoll. Levels over southern Rongelap and over Rongerik Atoll ranged from 4 to 7 ..mu..R/h. Levels were somewhat lower at Ailinginae Atoll (approximately 2 ..mu..R/h) and at Utirik Atoll (approximately 0.7 ..mu..R/h). The variations observed were consistent with what might be expected from the fallout pattern of the Bravo event. Levels at Ailuk, Likiep, Wotho and Ujelang Atolls and at Mejit and Jemo Islands were consistent with /sup 137/Cs activity, due to worldwide fallout, observed within the United States and at other locations in the central Pacific. These four atolls and the two islands, therefore, do not appear to have recieved any significant direct contamination from the Bravo event or the other tests conducted at Bikini and Enewetak Atolls.

  18. Peregrine falcon predation of endangered Laysan teal and Laysan Finches on remote Hawaiian atolls

    USGS Publications Warehouse

    Reynolds, Michelle H.; Nash, Sarah A.B.; Courtot, Karen

    2015-01-01

    We report the first records of Peregrine falcon (Falco peregrinus) predation on endangered Laysan teal (or duck; Anas laysanensis) and predation on endangered Laysan finches (Telespiza cantans). At Midway Atoll, vagrant Peregrine falcons killed ≥4% of a newly translocated Laysan teal population in 2006 and ≥2% in 2008. On Laysan Island during 2008–2009, remains of >76 Laysan finches (<1% of the population) were found at peregrine perches. On Midway Atoll, all depredated Laysan teal and other seabirds were recovered at kill sites on tarmac (runways). If the frequency or duration of vagrant raptors visitation increases at small atolls, this could pose a mortality risk to consider, especially during proposed translocations of endangered species. Vegetation restoration of abandoned runways near wetlands at Midway Atoll would provide cover and may help reduce mortality of endangered species due to vagrant raptors.

  19. Leg Muscle Mass and Foot Symptoms, Structure, and Function: The Johnston County Osteoarthritis Project

    PubMed Central

    Dufour, Alyssa B.; Hannan, Marian T.; Hillstrom, Howard J.; Katz, Patricia P.; Jordan, Joanne M.

    2016-01-01

    Background. Loss of muscle mass occurs with aging and in lower limbs it may be accelerated by foot problems. In this cross-sectional analysis, we evaluated the relationship of leg muscle mass to foot symptoms (presence or absence of pain, aching, or stiffness), structure while standing (high arch or low arch), and function while walking (pronated or supinated) in a community-based study of Caucasian and African American men and women who were 50–95 years old. Methods. In the Johnston County Osteoarthritis Project, leg muscle mass was measured with whole body dual-energy x-ray absorptiometry, and plantar foot pressure data, using predetermined values, were used to classify foot structure and function. Sex-specific crude and adjusted (age, body mass index, and race) linear regression models examined associations of leg muscle mass index (Leg muscle mass [kg] / Height [m]2) with foot symptoms, structure, and function. Results. Complete data were available for 1,037 participants (mean age 68 years, mean body mass index 31kg/m2, 68% women, 29% African American). In women, pronated foot function was associated with lower leg muscle mass in crude (p = .02), but not adjusted (p = .22), models. A low arch was associated with a higher leg muscle mass in adjusted models for both men and women (p < .01). Conclusions. Leg muscle mass was associated with foot structure in our biracial sample, whereas relations between leg muscle mass and foot function were attenuated by age, body mass index, and race. Future longitudinal analyses are needed to explain the temporal relationship between these conditions and how they relate to other aspects of impairment and physical function. PMID:26297655

  20. Response characteristics of vibration-sensitive interneurons related to Johnston's organ in the honeybee, Apis mellifera.

    PubMed

    Ai, Hiroyuki; Rybak, Jürgen; Menzel, Randolf; Itoh, Tsunao

    2009-07-10

    Honeybees detect airborne vibration by means of Johnston's organ (JO), located in the pedicel of each antenna. In this study we identified two types of vibration-sensitive interneurons with arborizations in the primary sensory area of the JO, namely, the dorsal lobe-interneuron 1 (DL-Int-1) and dorsal lobe-interneuron 2 (DL-Int-2) using intracellular recordings combined with intracellular staining. For visualizing overlapping areas between the JO sensory terminals and the branches of these identified interneurons, the three-dimensional images of the individual neurons were registered into the standard atlas of the honeybee brain (Brandt et al. [2005] J Comp Neurol 492:1-19). Both DL-Int-1 and DL-Int-2 overlapped with the central terminal area of receptor neurons of the JO in the DL. For DL-Int-1 an on-off phasic excitation was elicited by vibrational stimuli applied to the JO when the spontaneous spike frequency was low, whereas tonic inhibition was induced when it was high. Moreover, current injection into a DL-Int-1 led to changes of the response pattern from on-off phasic excitation to tonic inhibition, in response to the vibratory stimulation. Although the vibration usually induced on-off phasic excitation in DL-Int-1, vibration applied immediately after odor stimulation induced tonic inhibition in it. DL-Int-2 responded to vibration stimuli applied to the JO by a tonic burst and were most sensitive to 265 Hz vibration, which is coincident with the strongest frequency of airborne vibrations arising during the waggle dance. These results suggest that DL-Int-1 and DL-Int-2 are related to coding of the duration of the vibration as sensed by the JO. Copyright 2009 Wiley-Liss, Inc.

  1. Geologic map of the Fittstown 7.5΄ quadrangle, Pontotoc and Johnston Counties, Oklahoma

    USGS Publications Warehouse

    Lidke, David J.; Blome, Charles D.

    2017-01-09

    This 1:24,000-scale geologic map includes new geologic mapping as well as compilation and revision of previous geologic maps in the area. Field investigations were carried out during 2009–2011 that included mapping and investigations of the geology and hydrology of the Chickasaw National Recreation Area, Oklahoma, west of the map area.The Fittstown quadrangle is in Pontotoc and Johnston Counties in south-central Oklahoma, which is in the northeastern part of the Arbuckle Mountains. The Arbuckle Mountains are composed of a thick sequence of Paleozoic sedimentary rocks that overlie Lower Cambrian and Precambrian igneous rocks; these latter rocks are not exposed in the quadrangle. From Middle to Late Pennsylvanian time, the Arbuckle Mountains region was folded, faulted, and uplifted. Periods of erosion followed these Pennsylvanian mountain-building events, beveling this region and ultimately developing the current subtle topography that includes hills and incised uplands. The southern and northwestern parts of the Fittstown quadrangle are directly underlain by Lower Ordovician dolomite of the Arbuckle Group that has eroded to form an extensive, stream-incised upland containing the broad, gently southeast-plunging, Pennsylvanian-age Hunton anticline. The northeastern part of the map area is underlain by Middle Ordovician to Pennsylvanian limestone, shale, and sandstone units that predominantly dip northeast and form the northeastern limb of the Hunton anticline; this limb is cut by steeply dipping, northwest-southeast striking faults of the Franks fault zone. This limb and the Franks fault zone define the southwestern margin of the Franks graben, which is underlain by Pennsylvanian rocks in the northeast part of the map area.

  2. Leg Muscle Mass and Foot Symptoms, Structure, and Function: The Johnston County Osteoarthritis Project.

    PubMed

    Golightly, Yvonne M; Dufour, Alyssa B; Hannan, Marian T; Hillstrom, Howard J; Katz, Patricia P; Jordan, Joanne M

    2016-03-01

    Loss of muscle mass occurs with aging and in lower limbs it may be accelerated by foot problems. In this cross-sectional analysis, we evaluated the relationship of leg muscle mass to foot symptoms (presence or absence of pain, aching, or stiffness), structure while standing (high arch or low arch), and function while walking (pronated or supinated) in a community-based study of Caucasian and African American men and women who were 50-95 years old. In the Johnston County Osteoarthritis Project, leg muscle mass was measured with whole body dual-energy x-ray absorptiometry, and plantar foot pressure data, using predetermined values, were used to classify foot structure and function. Sex-specific crude and adjusted (age, body mass index, and race) linear regression models examined associations of leg muscle mass index (Leg muscle mass [kg]/Height [m](2)) with foot symptoms, structure, and function. Complete data were available for 1,037 participants (mean age 68 years, mean body mass index 31 kg/m(2), 68% women, 29% African American). In women, pronated foot function was associated with lower leg muscle mass in crude (p = .02), but not adjusted (p = .22), models. A low arch was associated with a higher leg muscle mass in adjusted models for both men and women (p < .01). Leg muscle mass was associated with foot structure in our biracial sample, whereas relations between leg muscle mass and foot function were attenuated by age, body mass index, and race. Future longitudinal analyses are needed to explain the temporal relationship between these conditions and how they relate to other aspects of impairment and physical function. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Pacific Enewetak Atoll Crater Exploration (PEACE) Program, Enewetak Atoll, Republic of the Marshall Islands. Part 3. Stratigraphic Analysis and Other Geologic and Geophysical Studies in Vicinity of KOA and OAK Craters,

    DTIC Science & Technology

    STRATIGRAPHY, *OCEAN BOTTOM, *CRATERS, NUCLEAR WARFARE, NUCLEAR EXPLOSIONS, DEFENSE SYSTEMS, SURVIVABILITY, DYNAMICS, OBSERVATION, UNDERWATER EXPLOSIONS, MARSHALL ISLANDS, ATOLLS , MINERALOGY, RADIATION CHEMISTRY.

  4. Meaning of radiation for those atolls in the northern part of the Marshall Islands that were surveyed in 1978

    SciTech Connect

    Bair, W.J.

    1982-11-01

    This book explains the results of the 1978 radiation measurements for the following atolls: Rongelap, Utrik, Taka, Bikar, Rongrik, Ailinginae, Likiep, Ailuk, Jemo, Mejit, Wotho and Ujelang. It explains the meaning of radiation, and about the radioactive particles that came from the atomic bombs, and about their distribution in the soil of each of these atolls. The book also gives information about the amounts of radiation people might receive now and later from radioactivity remaining on the atolls. (ACR)

  5. Analysis of Radiation Exposure for Personnel on the Residence Islands of Enewetak Atoll after Operation GREENHOUSE, 1951-1952.

    DTIC Science & Technology

    1987-04-20

    ON THE RESIDENCE ISLANDS OF ENEWETAK ATOLL AFTER OPERATION GREENHOUSE, 1951-1952. 12 PERSONAL AUTHOR(S) Thomas, C.; Goetz, J.; and Klemm, J. 13a TYPE...radiological environments are reconstructed for the residence islands of Enewetak Atoll following the roll-up phase of Operation GREENHOUSE in May 1951...to June 1952. For an individual assigned to Enewetak Atoll during this period, a mean dose of 1.5-2.0 rem would have been accrued, depending on the

  6. Asymmetric radiation of seismic waves from an atoll: nuclear tests in French Polynesia

    USGS Publications Warehouse

    Weber, Michael; Wicks, Charles W.; Krüger, Frank; Jahnke, Gunnar; Schlittenhardt, Jörg

    1998-01-01

    Seismic records of nuclear tests detonated in the Mururoa Atoll in French Polynesia show large unpredicted arrivals 2.2 and 4.5 seconds (X1 and X2) after the P-wave at the Australian Warramunga Array. These arrivals are not observed at the Canadian Yellowknife Array. X1 and X2 are also absent on Warramunga Array recordings of tests carried out at the Fangataufa Atoll situated 40 km SSE of Mururoa. Array analysis shows that X1 and X2 are produced within the source area. The layered crustal structure of the atoll, significant local inhomogeneities, and focusing effects due to the elongated shape and the steep flanks of the Mururoa Atoll are most likely responsible for X1 and X2. The form of Mururoa (28 × 10 km) and its East-West orientation is due to its location on the Austral Fracture Zone (AFZ). The Fangataufa Atoll on the other hand is almost circular (10 km diameter) and is unaffected by the dynamics along the AFZ. Our observations demonstrate that complicated structures in the source area can significantly alter the wave field at teleseismic distances and produce a large magnitude (mb) bias. A better understanding of the exact cause of these unusual seismic observations will only become possible, if the coordinates of the tests and information on the detailed 3-D structure of the atolls are released.

  7. Estimating the freshwater-lens thickness of atoll islands in the Federated States of Micronesia

    NASA Astrophysics Data System (ADS)

    Bailey, R. T.; Jenson, J. W.; Taboroši, D.

    2013-03-01

    The water resources of the 32 atolls of the Federated States of Micronesia (FSM) are under continual threat from El Niño-induced droughts and other natural hazards. With government policies emphasizing sustainable development of atoll-island communities, local managers are in need of tools for predicting changes in the availability of fresh groundwater, which communities depend upon during droughts that incapacitate rain-catchment systems. An application of a recently developed, readily portable algebraic model is demonstrated here, to estimate the freshwater-lens thickness of atoll islands in the FSM, a key component of FSM groundwater resource assessment. Specifically, the model provides estimates of the lens thickness of atoll islands in the FSM during normal and drought conditions. The model was tested for use in the FSM through comparison with available lens data under both average rainfall conditions and intense drought conditions, and then applied to major islands of each atoll within the FSM. Results indicate that out of 105 major islands on FSM atolls, only six would likely retain sufficient groundwater to sustain the local community during an intense drought.

  8. Meiobenthic and Macrobenthic Community Structure in Carbonate Sediments of Rocas Atoll (North-east, Brazil)

    NASA Astrophysics Data System (ADS)

    Netto, S. A.; Warwick, R. M.; Attrill, M. J.

    1999-01-01

    Rocas is the only atoll of the South Atlantic and it is built almost exclusively by coralline red algae, vermetid gastropods and encrusting foraminiferans. Patterns in the community structure of meiofauna and macrofauna, particularly nematodes and polychaetes, at Rocas Atoll, north-east Brazil, are determined and compared for different habitats: sublittoral, tidal flat, reef pools and lagoon. Nematodes and copepods were the most abundant meiofaunal taxa. In all studied habitats at Rocas Atoll, oligochaetes, nematodes and polychaetes numerically dominate the macrofauna. Univariate and multivariate analyses reveal clear differences in community structure between the habitats of the atoll, especially between the sublittoral and the inner habitats. The number of species, total density, diversity (H') and trophic structure vary significantly between the habitats, but the differences are dependent on which faunistic category (meiobenthic or macrobenthic) is analysed. Nematodes belonging to the Epsilonematidae and Draconematidae, together with a diverse community of meiobenthic polychaetes, characterize the sublittoral habitat of Rocas Atoll. Both meiofauna and macrofauna are depressed in the tidal flat, and the local sediment instability particularly affects the polychaete abundance. Reef pools and lagoons support a very dense aggregation of invertebrates, particularly the macrofauna, when compared with other carbonate reef sediments. However, differences in the structure of meiofauna and macrofauna communities between reef pools and lagoons are not significant. Changes in meiobenthic and macrobenthic community structure are related to the gradation in the physical environment of the atoll.

  9. Molluscicidal Metabolites from an Assemblage of Palmyra Atoll Cyanobacteria

    PubMed Central

    Pereira, Alban R.; Etzbach, Lena; Engene, Niclas; Müller, Rolf; Gerwick, William H.

    2011-01-01

    Molluscicides can play an important role in the control of schistosomiasis because snails of the genus Biomphalaria act as intermediate hosts for the parasite. Schistosomiasis is one of 13 neglected tropical diseases with high morbidity and mortality that collectively affect one billion of the world’s poorest population, mainly in developing countries. Thiopalmyrone (1) and palmyrrolinone (2), metabolites isolated from extracts of a Palmyra Atoll environmental assemblage of two cyanobacteria, cf. Oscillatoria and Hormoscilla spp., represent new and potent molluscicidal chemotypes against B. glabrata (LC50 = 8.3 and 6.0 μM, respectively). A slight enhancement in molluscicidal effect (LC50 = 5.0 μM) was observed when these two natural products were utilized as an equimolar binary mixture. PMID:21473610

  10. Molluscicidal metabolites from an assemblage of Palmyra Atoll cyanobacteria.

    PubMed

    Pereira, Alban R; Etzbach, Lena; Engene, Niclas; Müller, Rolf; Gerwick, William H

    2011-05-27

    Molluscicides can play an important role in the control of schistosomiasis because snails of the genus Biomphalaria act as intermediate hosts for the parasite. Schistosomiasis is one of 13 neglected tropical diseases with high morbidity and mortality that collectively affect one billion of the world's poorest population, mainly in developing countries. Thiopalmyrone (1) and palmyrrolinone (2), metabolites isolated from extracts of a Palmyra Atoll environmental assemblage of two cyanobacteria, cf. Oscillatoria and Hormoscilla spp., represent new and potent molluscicidal chemotypes against Biomphalaria glabrata (LC50=8.3 and 6.0 μM, respectively). A slight enhancement in molluscicidal effect (LC50=5.0 μM) was observed when these two natural products were utilized as an equimolar binary mixture.

  11. Blood bromine levels in a Pacific atoll population

    SciTech Connect

    Wielopolski, L.; Adams, W.H.; Heotis, P.M.

    1986-10-01

    Serum and red cells from 20 Marshallese on two atolls and from 10 subjects in New York were compared for their elemental composition employing an energy dispersive X-ray fluorescence technique. The elements analyzed in serum included Cl, Zn, and Br, whereas red cells were analyzed for Cl, K, Fe, Zn, Br, and Rb. Both Marshallese groups showed statistically significant elevations in serum Br (51 and 96%) and in red cell Br (393 and 478%) as compared to the New York group. The Marshallese Br/Cl ratio in serum and in red cells was elevated when compared to that of the New York group, whereas the Rb/K ratios were equivalent. The red cell Br/serum Br ratio was also elevated in the Marshallese subjects. There were no similar differences noted among the other elements tested. Drinking liquids in the Marshall Islands were analyzed for Br but did not provide a clear source for the elevated Br levels.

  12. Dolomite from reflux of moderate salinity brine, Enewetak Atoll

    SciTech Connect

    Goldstein, R.H.

    1996-12-31

    Dolomite from the Eocene of Enewetak Atoll provides a model for prediction of dolomite reservoirs. Others have noted dolomite below about 1200 meters at the base of permeable slope strata, and that dolomite postdates compaction, formed from fluids with {sup 87}Sr/{sup 86}Sr higher than the host strata, and that dolomite stable isotope values argue for precipitation from cool seawater or warm evaporated seawater. Dolomite contains cloudy cores, rich in primary fluid inclusions. Fluid inclusion ice melting ranges from -2.4 to -4.4{degrees}C (higher salinity than seawater; 44 to 85 ppt). Ratios of clear rim/cloudy core compared to new {sup 87}Sr/{sup 86}Sr and stable isotope data yield no correlation indicative of differences between clear rims and cloudy cores. Dolomite {sup 87}Sr/{sup 86}Sr are 0.70750 to 0.70873, but fluid inclusion {sup 87}Sr/{sup 86}Sr are 0.70957 to 0.71198, indicating inclusions best preserve end-member compositions for the dolomitizing fluid. Thus, dolomite precipitated from a young fluid that, surprisingly, may have interacted with some unknown source of radiogenic Sr. For fluid inclusions, Na/K is similar to seawater indicating components were derived from seawater evaporation and not from dissolution of an evaporate, Na/Sr and Ca/Mg are similar to seawater modified by rock/water interaction, and Cl/SO{sub 4} suggests removal of SO{sub 4} from pore fluids. The only viable explanation for the Enewetak dolomite is that young fluids evaporated to salinities slightly above seawater in Enewetak lagoon. The density contrast allowed for reflux deep into the atoll, discharging through permeable slope strata. This model could predict distributions of dolomite in any platform with slight restriction and appropriate climate.

  13. Dolomite from reflux of moderate salinity brine, Enewetak Atoll

    SciTech Connect

    Goldstein, R.H. )

    1996-01-01

    Dolomite from the Eocene of Enewetak Atoll provides a model for prediction of dolomite reservoirs. Others have noted dolomite below about 1200 meters at the base of permeable slope strata, and that dolomite postdates compaction, formed from fluids with [sup 87]Sr/[sup 86]Sr higher than the host strata, and that dolomite stable isotope values argue for precipitation from cool seawater or warm evaporated seawater. Dolomite contains cloudy cores, rich in primary fluid inclusions. Fluid inclusion ice melting ranges from -2.4 to -4.4[degrees]C (higher salinity than seawater; 44 to 85 ppt). Ratios of clear rim/cloudy core compared to new [sup 87]Sr/[sup 86]Sr and stable isotope data yield no correlation indicative of differences between clear rims and cloudy cores. Dolomite [sup 87]Sr/[sup 86]Sr are 0.70750 to 0.70873, but fluid inclusion [sup 87]Sr/[sup 86]Sr are 0.70957 to 0.71198, indicating inclusions best preserve end-member compositions for the dolomitizing fluid. Thus, dolomite precipitated from a young fluid that, surprisingly, may have interacted with some unknown source of radiogenic Sr. For fluid inclusions, Na/K is similar to seawater indicating components were derived from seawater evaporation and not from dissolution of an evaporate, Na/Sr and Ca/Mg are similar to seawater modified by rock/water interaction, and Cl/SO[sub 4] suggests removal of SO[sub 4] from pore fluids. The only viable explanation for the Enewetak dolomite is that young fluids evaporated to salinities slightly above seawater in Enewetak lagoon. The density contrast allowed for reflux deep into the atoll, discharging through permeable slope strata. This model could predict distributions of dolomite in any platform with slight restriction and appropriate climate.

  14. Wave energy gradients across a Maldivian atoll: Implications for island geomorphology

    NASA Astrophysics Data System (ADS)

    Kench, Paul S.; Brander, Robert W.; Parnell, Kevin E.; McLean, Roger F.

    2006-11-01

    Exposure to wave energy has been used to account for a range of ecological, geological and geomorphic processes in coral reef systems, but few attempts have been made to quantify spatial variations in energy at the atoll scale. This study presents results of measurements of wave energy on reef platforms across South Maalhosmadulu Atoll, Maldives and their implications for island geomorphology. The atoll has a perforated rim (37% effective aperture) and experiences predictable shifts in monsoon winds from the west (8 months) and northeast (4 months). Results show that wave energy affecting the atoll is considerably greater during the westerly monsoon. Atoll structure promotes significant changes in wave energy and wave characteristics across the atoll. Short period (3-8 s) monsoon-driven wave energy, which is significant on windward reefs, is dissipated on the peripheral reef network and the density of lagoonal patch reefs limits development of locally generated wind-wave energy across the lagoon. However, longer period swell (8-20 s) propagates through the lagoon to leeward reefs. A windward to leeward decay in wave energy is evident in the westerly monsoon, but not in the northeast monsoon, when long period swell (from the southwest) remains significant on western reefs. Net energy calculations that account for seasonal changes in wave energy across the atoll identify a steep west-east gradient that has geomorphic significance for island building. Western reefs are dominated by westerly flowing energy that is 4.5-7 times the total energy input elsewhere in the atoll. Wave energy on central reefs is balanced, whereas net energy on eastern reef platforms is dominated by eastward propagating waves. This steep energy gradient provides a physical explanation for the presence and distribution of islands on reef platforms across the atoll and provides quantitative support for the theory of Gardiner [Gardiner, J.S., 1903. The Fauna and Geography of the Maldives and

  15. Recovery Act: Johnston Rhode Island Combined Cycle Electric Generating Plant Fueled by Waste Landfill Gas

    SciTech Connect

    Galowitz, Stephen

    2013-06-30

    The primary objective of the Project was to maximize the productive use of the substantial quantities of waste landfill gas generated and collected at the Central Landfill in Johnston, Rhode Island. An extensive analysis was conducted and it was determined that utilization of the waste gas for power generation in a combustion turbine combined cycle facility was the highest and best use. The resulting project reflected a cost effective balance of the following specific sub-objectives. 1) Meet environmental and regulatory requirements, particularly the compliance obligations imposed on the landfill to collect, process and destroy landfill gas. 2) Utilize proven and reliable technology and equipment. 3) Maximize electrical efficiency. 4) Maximize electric generating capacity, consistent with the anticipated quantities of landfill gas generated and collected at the Central Landfill. 5) Maximize equipment uptime. 6) Minimize water consumption. 7) Minimize post-combustion emissions. To achieve the Project Objective the project consisted of several components. 1) The landfill gas collection system was modified and upgraded. 2) A State-of-the Art gas clean up and compression facility was constructed. 3) A high pressure pipeline was constructed to convey cleaned landfill gas from the clean-up and compression facility to the power plant. 4) A combined cycle electric generating facility was constructed consisting of combustion turbine generator sets, heat recovery steam generators and a steam turbine. 5) The voltage of the electricity produced was increased at a newly constructed transformer/substation and the electricity was delivered to the local transmission system. The Project produced a myriad of beneficial impacts. 1) The Project created 453 FTE construction and manufacturing jobs and 25 FTE permanent jobs associated with the operation and maintenance of the plant and equipment. 2) By combining state-of-the-art gas clean up systems with post combustion emissions control

  16. Interexaminer reliability of the Johnston and Friedman percussion scan of the thoracic spine: secondary data analysis using modified methods

    PubMed Central

    Cooperstein, Robert

    2012-01-01

    Objective The purpose of this study is to perform a secondary analysis using modified methods of previously reported data to analyze the amount of examiner concordance in the Johnston and Friedman percussion scan of the most fixated spinal level. Method A 2001 study evaluated interexaminer reliability of the percussive method of Johnston and Friedman for detecting altered segmental mobility (somatic dysfunction, spinal/segmental dysfunction, or chiropractic subluxation) in the thoracic spine. The original reported level of agreement using the κ statistic for discrete measures was only 0.07, judged “slight.” The data were reformatted to permit recalculating the degree of interexaminer agreement using the intraclass correlation coefficient statistic, which uses continuous analysis, unlike κ that performs discrete analysis. Following an initial calculation, the data were modified to reflect the caudally increasing vertebral height of the thoracic vertebrae. Results The reformatted and modified data, intraclass correlation coefficient (2,1) = 0.253 (0.100,0.482), showed the findings as “poor,” which is better interexaminer agreement for percussion motion palpation than the original reported κ value judged as “slight.” Conclusions Reanalyzing the data using an alternative statistical method showed greater interexaminer reliability than was originally reported. This secondary analysis demonstrates how study results may vary depending on the experimental design and statistical methods chosen for analysis. PMID:23449758

  17. Interexaminer reliability of the Johnston and Friedman percussion scan of the thoracic spine: secondary data analysis using modified methods.

    PubMed

    Cooperstein, Robert

    2012-09-01

    The purpose of this study is to perform a secondary analysis using modified methods of previously reported data to analyze the amount of examiner concordance in the Johnston and Friedman percussion scan of the most fixated spinal level. A 2001 study evaluated interexaminer reliability of the percussive method of Johnston and Friedman for detecting altered segmental mobility (somatic dysfunction, spinal/segmental dysfunction, or chiropractic subluxation) in the thoracic spine. The original reported level of agreement using the κ statistic for discrete measures was only 0.07, judged "slight." The data were reformatted to permit recalculating the degree of interexaminer agreement using the intraclass correlation coefficient statistic, which uses continuous analysis, unlike κ that performs discrete analysis. Following an initial calculation, the data were modified to reflect the caudally increasing vertebral height of the thoracic vertebrae. The reformatted and modified data, intraclass correlation coefficient (2,1) = 0.253 (0.100,0.482), showed the findings as "poor," which is better interexaminer agreement for percussion motion palpation than the original reported κ value judged as "slight." Reanalyzing the data using an alternative statistical method showed greater interexaminer reliability than was originally reported. This secondary analysis demonstrates how study results may vary depending on the experimental design and statistical methods chosen for analysis.

  18. Microbial ecology of four coral atolls in the Northern Line Islands.

    PubMed

    Dinsdale, Elizabeth A; Pantos, Olga; Smriga, Steven; Edwards, Robert A; Angly, Florent; Wegley, Linda; Hatay, Mark; Hall, Dana; Brown, Elysa; Haynes, Matthew; Krause, Lutz; Sala, Enric; Sandin, Stuart A; Thurber, Rebecca Vega; Willis, Bette L; Azam, Farooq; Knowlton, Nancy; Rohwer, Forest

    2008-02-27

    Microbes are key players in both healthy and degraded coral reefs. A combination of metagenomics, microscopy, culturing, and water chemistry were used to characterize microbial communities on four coral atolls in the Northern Line Islands, central Pacific. Kingman, a small uninhabited atoll which lies most northerly in the chain, had microbial and water chemistry characteristic of an open ocean ecosystem. On this atoll the microbial community was equally divided between autotrophs (mostly Prochlorococcus spp.) and heterotrophs. In contrast, Kiritimati, a large and populated ( approximately 5500 people) atoll, which is most southerly in the chain, had microbial and water chemistry characteristic of a near-shore environment. On Kiritimati, there were 10 times more microbial cells and virus-like particles in the water column and these microbes were dominated by heterotrophs, including a large percentage of potential pathogens. Culturable Vibrios were common only on Kiritimati. The benthic community on Kiritimati had the highest prevalence of coral disease and lowest coral cover. The middle atolls, Palmyra and Tabuaeran, had intermediate densities of microbes and viruses and higher percentages of autotrophic microbes than either Kingman or Kiritimati. The differences in microbial communities across atolls could reflect variation in 1) oceaonographic and/or hydrographic conditions or 2) human impacts associated with land-use and fishing. The fact that historically Kingman and Kiritimati did not differ strongly in their fish or benthic communities (both had large numbers of sharks and high coral cover) suggest an anthropogenic component in the differences in the microbial communities. Kingman is one of the world's most pristine coral reefs, and this dataset should serve as a baseline for future studies of coral reef microbes. Obtaining the microbial data set, from atolls is particularly important given the association of microbes in the ongoing degradation of coral reef

  19. Microbial Ecology of Four Coral Atolls in the Northern Line Islands

    PubMed Central

    Smriga, Steven; Edwards, Robert A.; Angly, Florent; Wegley, Linda; Hatay, Mark; Hall, Dana; Brown, Elysa; Haynes, Matthew; Krause, Lutz; Sala, Enric; Sandin, Stuart A.; Thurber, Rebecca Vega; Willis, Bette L.; Azam, Farooq; Knowlton, Nancy; Rohwer, Forest

    2008-01-01

    Microbes are key players in both healthy and degraded coral reefs. A combination of metagenomics, microscopy, culturing, and water chemistry were used to characterize microbial communities on four coral atolls in the Northern Line Islands, central Pacific. Kingman, a small uninhabited atoll which lies most northerly in the chain, had microbial and water chemistry characteristic of an open ocean ecosystem. On this atoll the microbial community was equally divided between autotrophs (mostly Prochlorococcus spp.) and heterotrophs. In contrast, Kiritimati, a large and populated (∼5500 people) atoll, which is most southerly in the chain, had microbial and water chemistry characteristic of a near-shore environment. On Kiritimati, there were 10 times more microbial cells and virus-like particles in the water column and these microbes were dominated by heterotrophs, including a large percentage of potential pathogens. Culturable Vibrios were common only on Kiritimati. The benthic community on Kiritimati had the highest prevalence of coral disease and lowest coral cover. The middle atolls, Palmyra and Tabuaeran, had intermediate densities of microbes and viruses and higher percentages of autotrophic microbes than either Kingman or Kiritimati. The differences in microbial communities across atolls could reflect variation in 1) oceaonographic and/or hydrographic conditions or 2) human impacts associated with land-use and fishing. The fact that historically Kingman and Kiritimati did not differ strongly in their fish or benthic communities (both had large numbers of sharks and high coral cover) suggest an anthropogenic component in the differences in the microbial communities. Kingman is one of the world's most pristine coral reefs, and this dataset should serve as a baseline for future studies of coral reef microbes. Obtaining the microbial data set, from atolls is particularly important given the association of microbes in the ongoing degradation of coral reef ecosystems

  20. ENSO-Related Variability in Wave Climate Drives Greater Erosion Potential on Central Pacific Atolls

    NASA Astrophysics Data System (ADS)

    Bramante, J. F.; Ashton, A. D.; Donnelly, J. P.

    2015-12-01

    The El Nino Southern Oscillation (ENSO) modulates atmospheric circulation across the equatorial Pacific over a periodic time scale of 2-7 years. Despite the importance of this climate mode in forcing storm generation and trade wind variability, its impact on the wave climate incident on central Pacific atolls has not been addressed. We used the NOAA Wavewatch III CFSR reanalysis hindcasts (1979-2007) to examine the influence of ENSO on sediment mobility and transport at Kwajalein Atoll (8.8°N, 167.7°E). We found that during El Nino event years, easterly trade winds incident on the atoll weakened by 4% compared to normal years and 17% relative to La Nina event years. Despite this decrease in wind strength, significant wave heights incident on the atoll were 3-4% greater during El Nino event years. Using machine learning to partition these waves revealed that the greater El Nino wave heights originated mainly from greater storm winds near the atoll. The southeastern shift in tropical cyclone genesis location during El Nino years forced these storm winds and contributed to the 7% and 16% increases in annual wave energy relative to normal and La Nina years, respectively. Using nested SWAN and XBeach models we determined that the additional wave energy during El Nino event years significantly increased potential sediment mobility at Kwajalein Atoll and led to greater net offshore transport on its most populous island. The larger storm waves likely deplete ocean-facing beaches and reef flats of sediment, but increase the supply of sediment to the atoll lagoon across open reef platforms that are not supporting islands. We discuss further explicit modelling of storms passing over the atoll to elucidate the confounding role of storm surge on the net erosional/depositional effects of these waves. Extrapolating our results to recent Wavewatch III forecasts leads us to conclude that climate change-linked increases in wave height and storm wave energy will increase erosion on

  1. Dolomitization of atolls by sea water convection flow: test of a hypothesis at Niue, South Pacific

    SciTech Connect

    Aharon, P.; Socki, R.A.; Chan, L.

    1987-03-01

    The core of the former atoll on Niue Island, South Pacific, is extensively dolomitized. A detailed stable isotope study reveals that the dolomites are uniformly enriched in /sup 18/O and /sup 13/C(delta /sup 18/O = 2.8 per thousand +/- 0.5; delta /sup 13/C = 2.0 per thousand +/- 0.3) relative to their carbonate precursor. The Sr isotope ratios are equally constant with depth yielding /sup 87/Sr//sup 86/Sr values between 0.70912 and 0.70916. The observed isotopic compositions point to sea water as the dominant dolomitizing fluid. The Sr age of the dolomites is younger than the biostratigraphic age (Mid to Late Miocene) placing the dolomitization event at Plio-Pleistocene time. A model of sea water convection is proposed for atoll dolomitization on the basis of a thermal gradient between the atoll and the ambient ocean water. Sea water is drawn through the atoll margin and transferred upward by convective flow delivering Mg to the sites of dolomite precipitation. Transported with the sea water are volcano-derived metals (Fe, Cu, Zn, Mn) as evidenced by the chemical gradient in the dolomite unit. It is suggested that the thermal convection model can find general application in atolls and other carbonate platforms containing dolomite where thermal instability exists. 70 references.

  2. Many Atolls May be Uninhabitable Within Decades Due to Climate Change

    NASA Astrophysics Data System (ADS)

    Storlazzi, Curt D.; Elias, Edwin P. L.; Berkowitz, Paul

    2015-09-01

    Observations show global sea level is rising due to climate change, with the highest rates in the tropical Pacific Ocean where many of the world’s low-lying atolls are located. Sea-level rise is particularly critical for low-lying carbonate reef-lined atoll islands; these islands have limited land and water available for human habitation, water and food sources, and ecosystems that are vulnerable to inundation from sea-level rise. Here we demonstrate that sea-level rise will result in larger waves and higher wave-driven water levels along atoll islands’ shorelines than at present. Numerical model results reveal waves will synergistically interact with sea-level rise, causing twice as much land forecast to be flooded for a given value of sea-level rise than currently predicted by current models that do not take wave-driven water levels into account. Atolls with islands close to the shallow reef crest are more likely to be subjected to greater wave-induced run-up and flooding due to sea-level rise than those with deeper reef crests farther from the islands’ shorelines. It appears that many atoll islands will be flooded annually, salinizing the limited freshwater resources and thus likely forcing inhabitants to abandon their islands in decades, not centuries, as previously thought.

  3. Subtle genetic structure reveals restricted connectivity among populations of a coral reef fish inhabiting remote atolls.

    PubMed

    Underwood, Jim N; Travers, Michael J; Gilmour, James P

    2012-03-01

    We utilized a spatial and temporal analyses of genetic structure, supplemented with ecological and oceanographic analysis, to assess patterns of population connectivity in a coral reef fish Chromis margaritifer among the unique and remote atolls in the eastern Indian Ocean. A subtle, but significant genetic discontinuity at 10 microsatellite DNA loci was detected between atoll systems corresponding with a low (≤ 1%) probability of advection across the hundreds of kilometers of open ocean that separates them. Thus, although genetic connections between systems are likely maintained by occasional long-distance dispersal of C. margaritifer larvae, ecological population connectivity at this spatial scale appears to be restricted. Further, within one of these atoll systems, significant spatial differentiation among samples was accompanied by a lack of temporal pairwise differentiation between recruit and adult samples, indicating that restrictions to connectivity also occur at a local scale (tens of kilometers). In contrast, a signal of panmixia was detected at the other atoll system studied. Lastly, greater relatedness and reduced genetic diversity within recruit samples was associated with relatively large differences among them, indicating the presence of sweepstakes reproduction whereby a small proportion of adults contributes to recruitment in the next generation. These results are congruent with earlier work on hard corals, suggesting that local production of larvae drives population replenishment in these atoll systems for a range of coral reef species.

  4. Modeling fresh water lens damage and recovery on atolls after storm-wave washover.

    PubMed

    Chui, Ting Fong May; Terry, James P

    2012-01-01

    The principal natural source of fresh water on scattered coral atolls throughout the tropical Pacific Ocean is thin unconfined groundwater lenses within islet substrates. Although there are many threats to the viability of atoll fresh water lenses, salinization caused by large storm waves washing over individual atoll islets is poorly understood. In this study, a mathematical modeling approach is used to examine the immediate responses, longer-term behavior, and subsequent (partial) recovery of a Pacific atoll fresh water lens after saline damage caused by cyclone-generated wave washover under different scenarios. Important findings include: (1) the saline plume formed by a washover event mostly migrates downward first through the top coral sand and gravel substrate, but then exits the aquifer to the ocean laterally through the more permeable basement limestone; (2) a lower water table position before the washover event, rather than a longer duration of storm washover, causes more severe damage to the fresh water lens; (3) relatively fresher water can possibly be found as a preserved horizon in the deeper part of an aquifer after disturbance, especially if the fresh water lens extends into the limestone under normal conditions; (4) post-cyclone accumulation of sea water in the central depression (swamp) of an atoll islet prolongs the later stage of fresh water lens recovery.

  5. Subtle genetic structure reveals restricted connectivity among populations of a coral reef fish inhabiting remote atolls

    PubMed Central

    Underwood, Jim N; Travers, Michael J; Gilmour, James P

    2012-01-01

    We utilized a spatial and temporal analyses of genetic structure, supplemented with ecological and oceanographic analysis, to assess patterns of population connectivity in a coral reef fish Chromis margaritifer among the unique and remote atolls in the eastern Indian Ocean. A subtle, but significant genetic discontinuity at 10 microsatellite DNA loci was detected between atoll systems corresponding with a low (≤ 1%) probability of advection across the hundreds of kilometers of open ocean that separates them. Thus, although genetic connections between systems are likely maintained by occasional long-distance dispersal of C. margaritifer larvae, ecological population connectivity at this spatial scale appears to be restricted. Further, within one of these atoll systems, significant spatial differentiation among samples was accompanied by a lack of temporal pairwise differentiation between recruit and adult samples, indicating that restrictions to connectivity also occur at a local scale (tens of kilometers). In contrast, a signal of panmixia was detected at the other atoll system studied. Lastly, greater relatedness and reduced genetic diversity within recruit samples was associated with relatively large differences among them, indicating the presence of sweepstakes reproduction whereby a small proportion of adults contributes to recruitment in the next generation. These results are congruent with earlier work on hard corals, suggesting that local production of larvae drives population replenishment in these atoll systems for a range of coral reef species. PMID:22822442

  6. Many atolls may be uninhabitable within decades due to climate change

    USGS Publications Warehouse

    Storlazzi, Curt; Elias, Edwin P.L.; Berkowitz, Paul

    2015-01-01

    Observations show global sea level is rising due to climate change, with the highest rates in the tropical Pacific Ocean where many of the world’s low-lying atolls are located. Sea-level rise is particularly critical for low-lying carbonate reef-lined atoll islands; these islands have limited land and water available for human habitation, water and food sources, and ecosystems that are vulnerable to inundation from sea-level rise. Here we demonstrate that sea-level rise will result in larger waves and higher wave-driven water levels along atoll islands’ shorelines than at present. Numerical model results reveal waves will synergistically interact with sea-level rise, causing twice as much land forecast to be flooded for a given value of sea-level rise than currently predicted by current models that do not take wave-driven water levels into account. Atolls with islands close to the shallow reef crest are more likely to be subjected to greater wave-induced run-up and flooding due to sea-level rise than those with deeper reef crests farther from the islands’ shorelines. It appears that many atoll islands will be flooded annually, salinizing the limited freshwater resources and thus likely forcing inhabitants to abandon their islands in decades, not centuries, as previously thought.

  7. Many Atolls May be Uninhabitable Within Decades Due to Climate Change

    PubMed Central

    Storlazzi, Curt D.; Elias, Edwin P.L.; Berkowitz, Paul

    2015-01-01

    Observations show global sea level is rising due to climate change, with the highest rates in the tropical Pacific Ocean where many of the world’s low-lying atolls are located. Sea-level rise is particularly critical for low-lying carbonate reef-lined atoll islands; these islands have limited land and water available for human habitation, water and food sources, and ecosystems that are vulnerable to inundation from sea-level rise. Here we demonstrate that sea-level rise will result in larger waves and higher wave-driven water levels along atoll islands’ shorelines than at present. Numerical model results reveal waves will synergistically interact with sea-level rise, causing twice as much land forecast to be flooded for a given value of sea-level rise than currently predicted by current models that do not take wave-driven water levels into account. Atolls with islands close to the shallow reef crest are more likely to be subjected to greater wave-induced run-up and flooding due to sea-level rise than those with deeper reef crests farther from the islands’ shorelines. It appears that many atoll islands will be flooded annually, salinizing the limited freshwater resources and thus likely forcing inhabitants to abandon their islands in decades, not centuries, as previously thought. PMID:26403195

  8. Many Atolls May be Uninhabitable Within Decades Due to Climate Change.

    PubMed

    Storlazzi, Curt D; Elias, Edwin P L; Berkowitz, Paul

    2015-09-25

    Observations show global sea level is rising due to climate change, with the highest rates in the tropical Pacific Ocean where many of the world's low-lying atolls are located. Sea-level rise is particularly critical for low-lying carbonate reef-lined atoll islands; these islands have limited land and water available for human habitation, water and food sources, and ecosystems that are vulnerable to inundation from sea-level rise. Here we demonstrate that sea-level rise will result in larger waves and higher wave-driven water levels along atoll islands' shorelines than at present. Numerical model results reveal waves will synergistically interact with sea-level rise, causing twice as much land forecast to be flooded for a given value of sea-level rise than currently predicted by current models that do not take wave-driven water levels into account. Atolls with islands close to the shallow reef crest are more likely to be subjected to greater wave-induced run-up and flooding due to sea-level rise than those with deeper reef crests farther from the islands' shorelines. It appears that many atoll islands will be flooded annually, salinizing the limited freshwater resources and thus likely forcing inhabitants to abandon their islands in decades, not centuries, as previously thought.

  9. Coastal groundwater exchange on a small Pacific atoll island: Roi Namur, Republic of the Marshall Islands

    NASA Astrophysics Data System (ADS)

    Oberle, Ferdinand K. J.; Swarzenski, Peter W.; Storlazzi, Curt

    2017-04-01

    Atoll islands, most of which only average 1-2 meters above today's sea level, provide a tremendous natural laboratory in which to study and better understand the intensifying impacts of high rates of sea-level rise on tropical reef-lined islands globally due to their unique geologic structure and limited water supply. Groundwater resources of atolls are typically minimal due to the low elevation and small surface area of the islands and are also subject to recurring droughts, and more frequent, storm-driven seawater overwash events. Although groundwater is the principal means of freshwater storage on atoll islands and is a major factor in determining the overall sustainability of island communities, hydrological data on how an aquifer will response to changes in sea-level rise or storm-driven overwash remain limited. We here present high-resolution time series hydrogeological and geochemical data to determine the role of the atoll's carbonate geology, land use, and atmospheric and oceanographic forcing in driving coastal groundwater exchange on the island of Roi Namur on Kwajalein Atoll in the Republic of the Marshall Islands. This information can provide new estimates on the recovery and resilience of coastal groundwater resources on such islands to expected climate change-driven perturbations.

  10. Oligocene sea-level falls recorded in mid-Pacific atoll and archipelagic apron settings

    NASA Astrophysics Data System (ADS)

    Schlanger, S. O.; Premoli Silva, I.

    1986-05-01

    Drilling results from mid-Pacific atoll and archipelagic apron sites in the Line Islands and Marshall Islands provinces lead to the conclusion that Oligocene sea-level falls detected in Atlantic passive margin sequences are also recorded in a mid-plate-tectonic setting in the Pacific Basin. The mid-Pacific sea-level falls are recorded by (a) the presence of distinct, coarse-grained, graded beds of turbidite origin, rich in reef-derived skeletal debris of Oligocene, Eocene, and Cretaceous age, that were redeposited in deep-water archipelagic apron carbonate sequences of middle and late Oligocene age now flanking the atolls and (b) a marked stratigraphic hiatus and solution unconformity in the subsurface of Enewetak atoll which dates an Oligocene period of atoll emergence correlative with both the deposition of the turbidites and the coastal offlap events discerned in Atlantic passive margins. Correlation of the subsidence path of Enewetak atoll with the development of the Oligocene solution unconformity shows that ca. 30 Ma sea level was as much as 100 m lower than at present.

  11. Shoreline changes in reef islands of the Central Pacific: Takapoto Atoll, Northern Tuamotu, French Polynesia

    NASA Astrophysics Data System (ADS)

    Duvat, Virginie K. E.; Pillet, Valentin

    2017-04-01

    Atoll reef islands are considered highly vulnerable to the impacts of climate change. While accelerated sea-level rise is expected to destabilize reef islands, ocean warming and acidification are considered as major threats to coral reef growth, which is of primary importance for the persistence of islands and of food supply to islanders. Using multi-date aerial imagery, shoreline and island changes between 1969 and 2013 were assessed on Takapoto Atoll, Northern Tuamotu region, in French Polynesia. Results show that over the 44-year study period, 41% of islands were stable in area while 33% expanded and 26% contracted. Island expansion was the dominant mode of change on the leeward side of the atoll. Tropical Cyclone Orama (category 3, 1983) contributed to shoreline and island change on the windward side of the atoll through the reworking of previous storm deposits and the injection of fresh sediments in the island system (with up to 62% of an island's land area being covered with fresh sediments). Human activities contributed significantly to shoreline and island change throughout the atoll through infrastructure construction, the removal of the indigenous vegetation from a number of islets and sediment mining.

  12. Radionuclide concentrations in underground waters of Mururoa and Fangataufa Atolls.

    PubMed

    Mulsow, S; Coquery, M; Dovlete, C; Gastaud, J; Ikeuchi, Y; Pham, M K; Povinec, P P

    1999-09-30

    In 1997 an expedition to Mururoa and Fangataufa Atolls was carried out to sample underground waters from cavity-chimneys and carbonate monitoring wells. The aim of this study was to determine the prevailing concentration and distribution status of radionuclides. Elemental analysis of interstitial waters was carried out in the water fraction as well as in particles collected at 11 underground monitoring wells. 238Pu, 239,240Pu, 241Am, 137Cs, 90Sr, 3H, 125Sb, 155Eu and 60Co were analyzed in both fractions by alpha-, beta- and gamma-spectrometry. Measurements showed that at 60% of the sites, pH and Eh seemed to be related to tidal cycles; in contrast HTO was constant during the sampling time. Interstitial waters from carbonates and transition zones shared similar chemical composition that were not different from that of the surrounding seawater. Waters collected from basalt cavities left after nuclear tests, (Aristee and Ceto) have a different chemical signature characterized by a deficiency in Mg, K and SO4 as well as enrichment in Sr, Si, Al and Cl compared to the rest of the stations. Radionuclide concentrations present in both, water and particulate fractions, were significantly higher at Ceto and Aristee than at any other monitoring wells, except for Fuseau and Mitre monitoring wells (Fangataufa) where values similar to Ceto were found (e.g. 239,240Pu: > 20 mBq g-1). Considering that Pu isotopes showed high Kd values compared to non-sorbing radionuclides such as 3H, 90Sr and 137Cs it is very unlikely that migration from cavities to monitoring wells accounts for the concentration of Pu isotopes and Am at Fuseau 30 and Mitre 27. Perhaps the contact of lagoon waters with the well before sealing could be a possible source of the transuranics found at these sites. The 238Pu/239,240Pu ratios measured in the particles were similar to that of the lagoon (0.38), thus supporting this hypothesis. The fact that transuranics were found only in the particle fraction, in the

  13. Sea level and coral atolls: Late holocene emergence in the Indian Ocean

    SciTech Connect

    Woodroffe, C. ); McLean, R. ); Polach, H.; Wallensky, E. )

    1990-01-01

    The Cocos (keeling) Islands in the eastern Indian Ocean were visited by Charles Darwin, who described geomorphological evidence that he considered supported his subsidence theory of coral-reef development. However, several other accounts of the reef islands have questioned Darwin's interpretation, and have suggested that a conglomerate platform that underlies most of the reef islands may indicate recent emergence of the atoll. Radiocarbon ages on corals from this conglomerate platform, reported here, indicate that it formed in the late Holocene. Fossil in situ microatolls above present upper coral growth limits, the elevation of associated beachrock, and the morphological similarity of the conglomerate platform to the present reef-flat deposits indicate a late Holocene sea level above the present relative to the atoll. The atoll has undergone at least 0.5 m of emergence since about 3000 yr B.P. This represents the first radiometrically dated evidence of Holocene emergence from islands in the eastern or central Indian Ocean.

  14. Hydrodynamics and thermal regime of a shallow reef-atoll rim

    NASA Astrophysics Data System (ADS)

    Maticka, S. A.; Lowe, R.; Monismith, S. G.

    2016-02-01

    As our understanding of reef-system hydrodynamics continues to advance, reef-atoll systems are still not fully understood. Of the reef-atoll research projects, few have focused on the smaller scale physics in these systems. Field observations and Delft3D model simulations are used to identify the dominant physics on the shallow outer rim ( 3 km wide) of a reef-atoll, Scott Reef, in the Timor Sea. Observations are used to understand what governs the thermal climate in these shallow regions. The reef-lagoon is characterized by a horseshoe shape that leaves the lagoon partially exposed to the ocean, with a meso-tidal regime (2-4 m). The physics on the rim appear to be dominated by tides. Temperature fluctuations follow a diurnal heating and cooling regime, with an additional tidal influence.

  15. Do human activities affect the picoplankton structure of the Ahe atoll lagoon (Tuamotu Archipelago, French Polynesia)?

    PubMed

    Bouvy, Marc; Dupuy, Christine; Pagano, Marc; Barani, Aude; Charpy, Loic

    2012-01-01

    The spatial variations of the picoplankton (photoautotrophic and heterotrophic microorganisms) in the Ahe atoll lagoon were studied in May and October 2008 to assess whether they were affected by human activities along the atoll. Spatial patterns were studied using 10 sampling stations chosen according to the location of the anthropogenic activities (pearl farming, harbor). Experiments were also carried out to determine whether bacterial growth, with or without predators, was limited by inorganic (N and P) substrates. The results showed that heterotrophic bacterioplankton abundance was superior to the photoautotrophic organisms, especially in May. Significant increases in bacterial abundance were observed in May after 24 h incubation with +P and +N (but not in October). All samples complied with the quality levels for fecal indicator bacteria (FIB) defined by the European Union and there was no evidence that human sewage had any impact on picoplankton over the whole atoll.

  16. Pearl oysters Pinctada margaritifera grazing on natural plankton in Ahe atoll lagoon (Tuamotu Archipelago, French Polynesia).

    PubMed

    Fournier, Jonathan; Dupuy, Christine; Bouvy, Marc; Couraudon-Réale, Marine; Charpy, Loïc; Pouvreau, Stephane; Le Moullac, Gilles; Le Pennec, Marcel; Cochard, Jean-Claude

    2012-01-01

    In atoll lagoons of French Polynesia, growth and reproduction of pearl oysters are mainly driven by plankton concentration. However, the actual diet of black-lip pearl oysters Pinctada margaritifera in these lagoons is poorly known. To fill this gap, we used the flow through chamber method to measure clearance rates of P. margaritifera in Ahe atoll lagoon (Tuamotu Archipelago, French Polynesia). We found: (i) that pearl oysters cleared plankton at a rate that was positively related to plankton biovolume, (ii) that nanoflagellates were the main source of carbon for the pearl oysters, and (iii) that the quantity and origin of carbon filtrated by pearl oysters was highly dependent on the concentration and composition of plankton. These results provide essential elements for the comprehension of growth and reproduction variability of pearl oysters in atoll lagoons of French Polynesia.

  17. An Ongoing Assessment of Osteoarthritis in African Americans and Caucasians in North Carolina: The Johnston County Osteoarthritis Project

    PubMed Central

    Jordan, Joanne M.

    2015-01-01

    Osteoarthritis (OA) is the most common type of arthritis and is frequently associated with significant disability. Its public health impact is increasing due to the aging of the population and the obesity epidemic. The Johnston County Osteoarthritis Project is an ongoing, population-based prospective cohort begun in 1990 to fill knowledge gaps about prevalence, incidence, and progression of OA, and its risk factors, in African American and Caucasian men and women in North Carolina. Critically important phenotypic differences were observed in patterns of multi-joint OA burden, with African Americans much less likely than Caucasians to have hand OA and much more likely to have multiple large joint involvement. Racial differences also exist in systemic bone and joint tissue biomarkers. Novel potentially modifiable risk factors identified in this cohort include selenium and blood lead levels. Selected key findings of this ongoing study will be discussed. PMID:26330661

  18. Superfund Record of Decision (EPA Region 1): Central Landfill Site, Operable Unit One, Johnston, RI, June 1994

    SciTech Connect

    Not Available

    1994-09-01

    This Decision Document presents the selected remedial action for the Central Landfill Superfund Site in Johnston, Rhode Island. In summary, the selected source control remedy consists of: Constructing a multi-layer RCRA C cap over the existing 121 acre Phase I area and incorporating the existing 32 acres of RIDEM approved cap on the side slopes; Hydraulic containment and treatment of groundwater in the hot spot area of the landfill and discharging the treated groundwater to either on-site surface water or the Cranston Waste Water Treatment Plant; Implementing deed restrictions on groundwater use and land development within property owned by the RISWMC; Initiating a long-term program of sampling and analysis of groundwater, surface water and air; Conducting a detailed evaluation of the existing landfill gas collection and combustion system; and Installing a chain link fence to prevent access.

  19. An Ongoing Assessment of Osteoarthritis in African Americans and Caucasians in North Carolina: The Johnston County Osteoarthritis Project.

    PubMed

    Jordan, Joanne M

    2015-01-01

    Osteoarthritis (OA) is the most common type of arthritis and is frequently associated with significant disability. Its public health impact is increasing due to the aging of the population and the obesity epidemic. The Johnston County Osteoarthritis Project is an ongoing, population-based prospective cohort begun in 1990 to fill knowledge gaps about prevalence, incidence, and progression of OA, and its risk factors, in African American and Caucasian men and women in North Carolina. Critically important phenotypic differences were observed in patterns of multi-joint OA burden, with African Americans much less likely than Caucasians to have hand OA and much more likely to have multiple large joint involvement. Racial differences also exist in systemic bone and joint tissue biomarkers. Novel potentially modifiable risk factors identified in this cohort include selenium and blood lead levels. Selected key findings of this ongoing study will be discussed.

  20. Blood bromine levels in a Pacific atoll population.

    PubMed

    Wielopolski, L; Adams, W H; Heotis, P M

    1986-10-01

    Serum and red cells from 20 Marshallese on two atolls and from 10 subjects in New York were compared for their elemental composition employing an energy dispersive X-ray fluorescence technique. The elements analyzed in serum included Cl, Zn, and Br, whereas red cells were analyzed for Cl, K, Fe, Zn, Br, and Rb. Both Marshallese groups showed statistically significant (P less than 0.01) elevations in serum Br (51 and 96%) and in red cell Br (393 and 478%) as compared to the New York group. The Marshallese Br/Cl ratio in serum and in red cells was elevated when compared to that of the New York group, whereas the Rb/K ratios were equivalent. The red cell Br/serum Br ratio was also elevated in the Marshallese subjects. There were no similar differences noted among the other elements tested. Drinking liquids in the Marshall Islands were analyzed for Br but did not provide a clear source for the elevated Br levels.

  1. Hydrodynamics of a Pacific Atoll System - Mechanisms for Flow and Ecological Implications

    NASA Astrophysics Data System (ADS)

    Rogers, J.; Monismith, S. G.; Koweek, D.; Torres, W.; Dunbar, R. B.

    2016-02-01

    We present characterization of the waves and hydrodynamics of the Palmyra Atoll system based on field measurements from 2012 to 2014, and modeling simulations using a coupled waves and three-dimensional hydrodynamic model (COAWST). At the scale of the atoll itself, strong regional flows create flow separation and a well-defined wake, similar to the classical fluid mechanics problem of flow past a cylinder. Circulation within the atoll is primarily governed by tides and waves, and secondarily by wind and regional currents. Tidally driven flow is important at all field sites, and tidal phase delay occurs between the forereef and interior lagoons. Wave driven flow is significant at most of the field sites, and is a strong function of the dominant wave direction. The wave climate is characterized by strong northerly waves which drive across the atoll to the south and through the lagoon system to the west and out the channel to offshore. Wind driven flow is generally weak, except on the shallow terraces. Bottom stress is significant for depths less than about 10 m. Based on Lagrangian float tracks, the mean age appears to clearly differentiate the geomorphic structures. The biological cover shows significant trends with mean flow, age and temperature. While high mean flow appears to differentiate productive coral regions, low water age and low temperature appear to be the most important variables for distinguishing between biological cover types at this site. The resulting connectivity within the atoll system shows that the general trends follow the mean flow paths; however, some connectivity exists between all ten regions of the atoll system.

  2. Variation in diversity of coral reef fish between French Polynesian atolls

    NASA Astrophysics Data System (ADS)

    Galzin, R.; Planes, S.; Dufour, V.; Salvat, B.

    1994-07-01

    The diversity of coral reef fish in seven atolls in French Polynesia is analyzed with respect to geomorphological characteristics of the atolls. The results show that size of the lagoon is more important than confinement in affecting overall fish diversity. This result suggests that island biogeographic theory, as developed by MacArthur and Wilson for terrestrial animals, also applies to reef fish in that more area gives more habitat complexity which, in turn, supports higher fish diversity. However, species diversity within a given family appears to be affected more by ecological parameters, such as living coral cover, food diversity, and reproductive behavior, than geomorphological features.

  3. The record of Pliocene sea-level change at Enewetak Atoll

    USGS Publications Warehouse

    Wardlaw, B.R.; Quinn, T.M.

    1991-01-01

    Detailed seismic stratigraphy, lithostratigraphy, and chemostratigraphy indicate that atoll-wide subaerial exposure surfaces (major disconformities) developed during major sea-level lowstands form prominent seismic reflectors and are coincident with biostratigraphic breaks in the Plio-Pleistocene on Enewetak Atoll. Sea-level models based on the stratigraphic position and age of major disconformities suggest a maximum sea-level highstand elevation of 36 m above present sea level and a maximum sea-level lowstand elevation of 63 m below present sea level for the Pliocene. ?? 1991.

  4. The record of Pliocene sea-level change at Enewetak Atoll

    NASA Astrophysics Data System (ADS)

    Wardlaw, Bruce R.; Quinn, Terrence M.

    Detailed seismic stratigraphy, lithostratigraphy, and chemostratigraphy indicate that atoll-wide subaerial exposure surfaces (major disconformities) developed during major sea-level lowstands form prominent seismic reflectors and are coincident with biostratigraphic breaks in the Plio-Pleistocene on Enewetak Atoll. Sea-level models based on the stratigraphic position and age of major disconformities suggest a maximum sea-level highstand elevation of 36 m above present sea level and a maximum sea-level lowstand elevation of 63 m below present sea level for the Pliocene.

  5. A study of the Brazilian Fernando de Noronha island and Rocas atoll wakes in the tropical Atlantic

    NASA Astrophysics Data System (ADS)

    Tchamabi, Christine C.; Araujo, Moacyr; Silva, Marcus; Bourlès, Bernard

    2017-03-01

    Observational data and numerical modeling were used to investigate oceanic current wakes surrounding Fernando de Noronha Island (3°51‧S-32°25‧W) and Rocas Atoll (3°52‧S-33°49‧W). These two Brazilian systems are located in the western tropical Atlantic region and are under the influence of the westward flow of the central South Equatorial Current (cSEC). In order to highlight the effects of wakes on ocean dynamics, two different numerical simulations were performed, using the Regional Oceanic Modeling System (ROMS): the first one including Fernando de Noronha Island and Rocas Atoll (Scenario I) and the second one with artificial removal of the island and atoll (Scenario NI). Simulations are validated through the Scenario I that well reproduces the wakes that give rise to the development of eddies downstream of FN and AR. These mesoscale structures have a strong influence on the thermodynamic properties surrounding the Island and the Atoll. Scenario NI allows evidence of the presence of an Island and Atoll shoaling mixed layer throughout the year, primarily on the western side of the Island and the Atoll. Mixing at the base of the mixed layer, inducing a subsurface cooling, is also enhanced in the downstream portion of the Island and Atoll, particularly when the cSEC is strengthened. These simulations support the ;island mass effect; on the high productivity of subsurface waters generally observed on the western side of these islands.

  6. A coupled wave-hydrodynamic model of a highly frictional atoll reef system: mechanisms for flow, connectivity, and ecological implications

    NASA Astrophysics Data System (ADS)

    Rogers, J.; Monismith, S. G.; Fringer, O. B.; Koweek, D.; Dunbar, R. B.

    2016-12-01

    We present a hydrodynamic analysis of an atoll system from modeling simulations using a coupled wave and three-dimensional hydrodynamic model (COAWST) applied to Palmyra Atoll in the Central Pacific. This is the first time the vortex force formalism has been applied in a highly frictional reef environment. The model results agree well with field observations considering the model complexity in terms of bathymetry, bottom roughness, and forcing (waves, wind, metrological, tides, regional boundary conditions), and open boundary conditions. At the atoll scale, strong regional flows create flow separation and a well-defined wake, similar to 2D flow past a cylinder. Circulation within the atoll is typically forced by waves and tides, with strong waves from the north driving flow from north to south across the atoll, and from east to west through the lagoon system. Bottom stress is significant for depths less than about 60 m, and in addition to the model bathymetry, is important for correct representation of flow in the model. Connectivity within the atoll system shows that the general trends follow the mean flow paths. However, some connectivity exists between all regions of the atoll system due to nonlinear processes such as eddies and tidal phasing. While high mean flow and travel time less than 20 hours appears to differentiate very productive coral regions, low temperature and moderate wave stress appear to be the most ideal conditions for high coral cover on Palmyra.

  7. A coupled wave-hydrodynamic model of an atoll with high friction: Mechanisms for flow, connectivity, and ecological implications

    NASA Astrophysics Data System (ADS)

    Rogers, Justin S.; Monismith, Stephen G.; Fringer, Oliver B.; Koweek, David A.; Dunbar, Robert B.

    2017-02-01

    We present a hydrodynamic analysis of an atoll system from modeling simulations using a coupled wave and three-dimensional hydrodynamic model (COAWST) applied to Palmyra Atoll in the Central Pacific. This is the first time the vortex force formalism has been applied in a highly frictional reef environment. The model results agree well with field observations considering the model complexity in terms of bathymetry, bottom roughness, and forcing (waves, wind, metrological, tides, regional boundary conditions), and open boundary conditions. At the atoll scale, strong regional flows create flow separation and a well-defined wake, similar to 2D flow past a cylinder. Circulation within the atoll is typically forced by waves and tides, with strong waves from the north driving flow from north to south across the atoll, and from east to west through the lagoon system. Bottom stress is significant for depths less than about 60 m, and in addition to the model bathymetry, is important for correct representation of flow in the model. Connectivity within the atoll system shows that the general trends follow the mean flow paths. However, some connectivity exists between all regions of the atoll system due to nonlinear processes such as eddies and tidal phasing. Moderate wave stress, short travel time (days since entering the reef system), and low temperature appear to be the most ideal conditions for high coral cover at this site.

  8. Larger foraminifer biostratigraphy of PEACE boreholes, Enewetak Atoll, Western Pacific Ocean. Geologic and geophysical investigations of Enewetak Atoll, Republic of the Marshall Islands. Professional paper

    SciTech Connect

    Gibson, T.G.; Margerum, R.

    1991-01-01

    Larger foraminiferal assemblages, including Lepidocyclina orientalis, Miogypsina thecideaeformis, Miogypsinoides dehaartii, etc., and a smaller foraminifer, Austrotrillina striata, are used to correlate upper Oligocene and lower Miocene strata in the Pacific Atoll Exploration Program (PEACE) boreholes at Enewetak Atoll, Republic of the Marshall Islands, western Pacific Ocean, with the Te and Tf zones of the previously established Tertiary Far East Letter Zonation. Correlation using these two benthic groups is critical because calcareous nannofossils and planktic foraminifers are absent in the lower Miocene strata. Biostratigraphic data from these boreholes delineate a thick (greater than 700 feet) sequence of upper Oligocene and lower Miocene strata corresponding to lower and upper Te zone. These strata document a major period of carbonate accumulation at Enewetak during the Late Oligocene and early Miocene (26 to 18 million years ago).

  9. Radionuclide concentrations in fish and invertebrates from Bikini Atoll

    SciTech Connect

    Noshkin, V.E.; Wong, K.M.; Eagle, R.J.; Jokela, T.A.; Brunk, J.A.

    1988-01-01

    As in other global studies, /sub 137/Cs was found in the highest concentrations in edible flesh of all species of fish and in the lowest concentrations in the bone or liver. The mean concentration of /sup 137/Cs in muscle of reef fish from the southern part of the atoll is comparable to the global-fallout concentration measured in market samples of fish collected from Chicago, IL, USA, in 1982. Strontium-90 is associated generally with non-edible parts of fish, such as bone or viscera. Twenty-five to fifty percent of the total body burden of /sub 60/Co is accumulated in the muscle tissue; the remainder is distributed among the liver, skin, and viscera. The mean concentration of /sub 60/Co in fish has been decreasing at a rate faster than radiological decay alone. Most striking is the range of /sup 207/Bi concentrations among different species of fish collected at the same time and place. Highest concentrations of /sup 207/Bi were consistently detected in the muscle and other tissues of goatfish and some of the pelagic lagoon fish. In other reef fish, such as mullet, surgeonfish, and parrotfish, /sub 207/Bi was usually below detection limits by gamma spectrometry. Over 70% of the whole-body activity of /sup 207/Bi in goatfish is associated with the muscle tissue, whereas less than 5% is found in the muscle of mullet and surgeonfish. Neither /sup 239 +240/Pu nor /sup 241/Am is accumulated significantly in the muscle tissue of any species of fish. Apparently, /sup 238/Pu is in a more readily available form for accumulation by fishes than /sup 239 +240/Pu. Based on a daily ingestion rate of 200 g of fish flesh, dose rates to individuals through the fish-food ingestion pathway are well below current Federal guidelines. 24 refs., 1 fig., 27 tabs

  10. Radiological conditions at the Southern Islands of Rongelap Atoll

    SciTech Connect

    Robison, W.L.; Conrado, C.L.

    1996-03-01

    The data presented in the following tables is the total available for each southern island; they include both the data from the 1978 Northern Marshall Island Radiological Survey (NMIRS) and trips to Rongelap Atoll from 1986 through 1991. There are additional samples that were taken at Rongelap Island in 1990 and 1991, and the data are unavailable for this report. In one table we present the number of vegetation samples collected in the 1978 NMIRS and from 1986 through 1991. Again, the majority of the {sup 137}Cs is from the 1986-1991 trips. We have not made additional analyses of {sup 239+240}Pu, {sup 241}Am and {sup 90}Sr because the concentrations are very low and these radionuclides contribute less than 5% of an already very small dose. In another table we show the number of soil samples collected at each island in 1978 and the number collected since 1986. Most of the data are from 1986 through 1991. The major exception is {sup 90}Sr where all of the data are from the 1978 NMIRS. We have done some additional Pu analyses of soils from Rongelap Eniaetok, and Borukka Island but none of the other southern islands. A significant amount of new data for {sup 137}Cs and {sup 241}Am have been generated from the samples collected from 1986 through 1991. The data are presented in the form of summary tables, graphics, detailed appendices and aerial photographs of the islands with the sample locations marked. The identified sample locations from the 1978 NMIRS will be added later.

  11. Small herbivores suppress algal accumulation on Agatti atoll, Indian Ocean

    NASA Astrophysics Data System (ADS)

    Cernohorsky, Nicole H.; McClanahan, Timothy R.; Babu, Idrees; Horsák, Michal

    2015-12-01

    Despite large herbivorous fish being generally accepted as the main group responsible for preventing algal accumulation on coral reefs, few studies have experimentally examined the relative importance of herbivore size on algal communities. This study used exclusion cages with two different mesh sizes (1 × 1 cm and 6 × 6 cm) to investigate the impact of different-sized herbivores on algal accumulation rates on the shallow (<2 m) back-reef of Agatti atoll, Lakshadweep. The fine-mesh cages excluded all visible herbivores, which had rapid and lasting effects on the benthic communities, and, after 127 d of deployment, there was a visible and significant increase in algae (mainly macroalgae) with algal volume being 13 times greater than in adjacent open areas. The coarse-mesh cages excluded larger fishes (>8 cm body depth) while allowing smaller fishes to access the plots. In contrast to the conclusions of most previous studies, the exclusion of large herbivores had no significant effect on the accumulation of benthic algae and the amount of algae present within the coarse-mesh cages was relatively consistent throughout the experimental period (around 50 % coverage and 1-2 mm height). The difference in algal accumulation between the fine-mesh and coarse-mesh cages appears to be related to the actions of small individuals from 12 herbivorous fish species (0.17 ind. m-2 and 7.7 g m-2) that were able to enter through the coarse mesh. Although restricted to a single habitat, these results suggest that when present in sufficient densities and diversity, small herbivorous fishes can prevent the accumulation of algal biomass on coral reefs.

  12. Sewage contamination of a densely populated coral 'atoll' (Bermuda).

    PubMed

    Jones, Ross; Parsons, Rachel; Watkinson, Elaine; Kendell, David

    2011-08-01

    Bermuda is a densely populated coral 'atoll' located on a seamount in the mid-Atlantic (Sargasso Sea). There is no national sewerage system and the ∼20 × 10(6) L of sewage generated daily is disposed of via marine outfalls, cess pits/septic tanks underneath houses and through waste disposal (injection) wells. Gastrointestinal (GI) enterococci concentrations were measured in surface seawater samples collected monthly at multiple locations across the island over a 5-year period. According to the EU Bathing Water Directive microbial classification categories, 18 of the sites were in the 'excellent' category, four sites in the 'good', five sites were in the 'sufficient' and three sites in the 'poor' categories. One of the sites in the 'poor' category is beside a popular swimming beach. Between 20-30% of 58 sub tidal sediment samples collected from creeks, coves, bays, harbours and marinas in the Great Sound complex on the western side of Bermuda tested positive for the presence of the human specific bacterial biomarker Bacteroides (using culture-independent PCR-based methods) and for the faecal biomarker coprostanol (5β-cholestan-3-β-ol, which ranged in concentration from <0.05-0.77 mg kg( - 1). There was a significant statistical correlation between these two independent techniques for faecal contamination identification. Overall the microbial water quality and sedimentary biomarker surveys suggest sewage contamination in Bermuda was quite low compared with other published studies; nevertheless, several sewage contamination hotpots exist, and these could be attributed to discharge of raw sewage from house boats, from nearby sewage outfalls and leakage from septic tanks/cess pits.

  13. Population dynamics of Siderastrea stellata Verrill, 1868 from Rocas Atoll, RN: implications for predicted climate change impacts at the only South Atlantic atoll.

    PubMed

    Miranda, Andrea L; Cordeiro, Soraia M; Reis, Joice N; Cardoso, Lucas G; Guimarães, Alaíse G

    2017-01-01

    Coral reefs are one of the most vulnerable ecosystems to ocean warming and acidification, and it is important to determine the role of reef building species in this environment in order to obtain insight into their susceptibility to expected impacts of global changes. Aspects of the life history of a coral population, such as reproduction, growth and size-frequency can contribute to the production of models that are used to estimate impacts and potential recovery of the population, acting as a powerful tool for the conservation and management of those ecosystems. Here, we present the first evidence of Siderastrea stellata planulation, its early growth, population size-frequency distribution and growth rate of adult colonies in Rocas Atoll. Our results, together with the environmental protection policies and the absence of anthropogenic pressures, suggest that S. stellata population may have a good potential in the maintenance and recovery in the atoll. However, our results also indicate an impact on corals' recruitment, probably as a consequence of the positive temperature anomaly that occurred in 2010. Thus, despite the pristine status of Rocas Atoll, the preservation of its coral community seems to be threatened by current global changes, such as more frequent thermal stress events.

  14. 48 CFR 252.236-7012 - Military construction on Kwajalein Atoll-evaluation preference.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Kwajalein Atoll-evaluation preference. 252.236-7012 Section 252.236-7012 Federal Acquisition Regulations... Kwajalein Atoll—evaluation preference. As prescribed in 236.570(c)(2), use the following provision: Military Construction on Kwajalein Atoll—Evaluation Preference (MAR 1998) (a) Definitions. As used in this provision—...

  15. Transmitting Traditional Values in New Schools: Elementary Education of Pulap Atoll.

    ERIC Educational Resources Information Center

    Flinn, Juliana

    1992-01-01

    Data from Pulap Atoll in Chuuk State (Micronesia) indicate ways in which indigenous culture can transform formal Western schooling. Although the educational system ostensibly derives from a U.S. model and occurs in a context that islanders recognize as nontraditional, many aspects of schooling continue to transmit Pulapese culture. (SLD)

  16. Oxygen and carbon isotopic composition of limestones and dolomites, bikini and eniwetok atolls.

    PubMed

    Gross, M G; Tracey, J I

    1966-03-04

    Aragonitic, unconsolidated sediments from the borings on the Eniwetok and Bikini atolls are isotopically identical with unaltered skeletal fragments, whereas the recrystallized limestones exhibit isotopic variations resulting from alteration in meteoric waters during periods of emergence. Dolomites and associated calcites are enriched in O(18), perhaps because of interaction with hypersaline brines.

  17. 48 CFR 252.236-7012 - Military construction on Kwajalein Atoll-evaluation preference.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Kwajalein Atoll-evaluation preference. 252.236-7012 Section 252.236-7012 Federal Acquisition Regulations... Kwajalein Atoll—evaluation preference. As prescribed in 236.570(c)(2), use the following provision: Military Construction on Kwajalein Atoll—Evaluation Preference (MAR 1998) (a) Definitions. As used in this provision—...

  18. 48 CFR 252.236-7012 - Military construction on Kwajalein Atoll-evaluation preference.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Kwajalein Atoll-evaluation preference. 252.236-7012 Section 252.236-7012 Federal Acquisition Regulations... Kwajalein Atoll—evaluation preference. As prescribed in 236.570(c)(2), use the following provision: Military Construction on Kwajalein Atoll—Evaluation Preference (MAR 1998) (a) Definitions. As used in this provision—...

  19. Collection and processing of plant, animal and soil samples from Bikini, Enewetak and Rongelap Atolls

    SciTech Connect

    Stuart, M.L.

    1995-09-01

    The United States used the Marshall Islands for its nuclear weapons program testing site from 1946 to 1958. The BRAVO test was detonated at Bikini Atoll on March 1, 1954. Due to shifting wind conditions at the time of the nuclear detonation, many of the surrounding Atolls became contaminated with fallout (radionuclides carried by the wind currents). Lawrence Livermore National Laboratory`s (LLNL) Marshall Islands Project has been responsible for the collecting, processing, and analyzing of food crops, vegetation, soil, water, animals, and marine species to characterize the radionuclides in the environment, and to estimate dose at atolls that may have been contaminated. Tropical agriculture experiments reducing the uptake of {sup 137}Cs have been conducted on Bikini Atoll. The Marshall Islands field team and laboratory processing team play an important role in the overall scheme of the Marshall Islands Dose Assessment and Radioecology Project. This report gives a general description of the Marshall Islands field sampling and laboratory processing procedures currently used by our staff.

  20. The natural history of Enewetak Atoll: Volume 2, Biogeography and systematics

    SciTech Connect

    Devaney, D.M.; Reese, E.S.; Burch, B.L.; Helfrich, P.

    1987-01-01

    The two volumes of The Natural History of Enewetak Atoll summarize research done at the Mid-Pacific Research Laboratory from 1954 to 1984 under the auspices of the Department of Energy. Volume 2 of The Natural History of Enewetak Atoll provides information on the taxonomy of animals and plants known to occur at Enewetak Atoll. The collections on which the checklists in each chapter are based are housed at the Bernice P. Bishop Museum in Honolulu and the US National Museum of Natural History, Smithsonian Institution, Washington, DC. In addition to the species checklists, each chapter in Volume 2 provides a succinct summary of the biota with respect to endemism, range extensions, and other features that set the Enewetak biota apart from those one might expect to find on equivalent Indo-Pacific islands. This compendium of taxonomic information for an atoll should prove of immense value to scientists interested in biogeography and evolutionary biology of island ecosystems for years to come. Individual chapters are processed separately for the data base.

  1. Transmitting Traditional Values in New Schools: Elementary Education of Pulap Atoll.

    ERIC Educational Resources Information Center

    Flinn, Juliana

    1992-01-01

    Data from Pulap Atoll in Chuuk State (Micronesia) indicate ways in which indigenous culture can transform formal Western schooling. Although the educational system ostensibly derives from a U.S. model and occurs in a context that islanders recognize as nontraditional, many aspects of schooling continue to transmit Pulapese culture. (SLD)

  2. Culture, hydrology, and other situational controls on atoll freshwater availability (Majuro, Republic of the Marshall Islands)

    NASA Astrophysics Data System (ADS)

    Shuster, W.

    2016-12-01

    The comparatively uncertain rainfall catch and rising seas in isolated North Pacific atoll communities has presented serious challenges to maintain human communities with freshwater volume. Moreover, the feudal hierarchy, which structures social and economic relationships among local governance and citizens contributes equally to problems and potential solutions. These relationships modulate the availability of critical ecosystem services generated by freshwater, with additional constraints contributed by climate change, rainfall variability (e.g., current El Niño climate pattern), and continuous threat of drought. The major freshwater resources for an atoll are the groundwater freshwater lens, residential and commercial rainwater harvesting, large-scale rainfall catchments (e.g., an airport runway), imported-virtual water, or desalinization subsidies. The significance of each of these resources scale across different atolls according to size, topography, soils, population, infrastructure, and land ownership. The potential integration and coordination of these water resources is largely unrealized due to land ownership, the lack of a contiguous catchment area, uneven and fractured governance. The situational aspects are further characterized by feuding among families and communities (some resource rich, some resource poor), and conflicting land use priorities where agriculture placement and practice can compromise the quality of already limited freshwater resources. This presentation uses the example of Majuro atoll (Republic of the Marshall Islands), field data and other observations, to illustrate sociohydrologic-drivers of freshwater availability, and suggests approaches that may improve on current and ongoing threats to public health and well-being.

  3. Calcium carbonate production of the mare incognitum, the upper windward reef slope, at enewetak atoll.

    PubMed

    Smith, S V; Harrison, J T

    1977-08-05

    Corals and algal pavement produce calcium carbonate more slowly on the windward reef slope of Enewetak Atoll than on the reef flat despite the high standing crop of reef-building organisms on the slope. The capacity of reefs to remain at or near sea level is therefore not determined primarily by growth on the seaward slope.

  4. Tsunami hazard potential for the equatorial southwestern Pacific atolls of Tokelau from scenario-based simulations

    NASA Astrophysics Data System (ADS)

    Orpin, A. R.; Rickard, G. J.; Gerring, P. K.; Lamarche, G.

    2015-07-01

    Devastating tsunami over the last decade have significantly heightened awareness of the potential consequences and vulnerability to tsunami for low-lying Pacific islands and coastal regions. Our tsunami risk assessment for the atolls of the Tokelau Islands was based on a tsunami source-propagation-inundation model using Gerris Flow Solver, adapted from the companion study by Lamarche et al. (2015) for the islands of Wallis and Futuna. We assess whether there is potential for tsunami flooding on any of the village islets from a series of fourteen earthquake-source experiments that apply a combination of well-established fault parameters to represent plausible "high-risk scenarios" for each of the tsunamigenic sources. Earthquake source location and moment magnitude were related to tsunami wave heights and tsunami flood depths simulated for each of the three atolls of Tokelau. This approach was adopted to yield indicative and instructive results for a community advisory, rather than being fully deterministic. Results from our modelling show that wave fields are channelled by the bathymetry of the Pacific basin in such a way that the swathes of the highest waves sweep immediately northeast of the Tokelau Islands. From our series of limited simulations a great earthquake from the Kuril Trench poses the most significant inundation threat to Tokelau, with maximum modelled-wave heights in excess of 1 m, which may last a few hours and include several wave trains. Other sources can impact specific sectors of the atolls, particularly from regional sources to the south, and northern and eastern distant sources that generate trans-Pacific tsunami. In many cases impacts are dependent on the wave orientation and direct exposure to the oncoming tsunami. This study shows that dry areas remain around the villages in nearly all our "worst-case" tsunami simulations of the Tokelau Islands. Consistent with the oral history of little or no perceived tsunami threat, simulations from the

  5. Using Darwin's theory of atoll formation to improve tsunami hazard mitigation in the Pacific

    NASA Astrophysics Data System (ADS)

    Goff, J. R.; Terry, J. P.

    2012-12-01

    It is 130 years since Charles Darwin's death and 176 years since he his penned his subsidence theory of atoll formation on 12th April 1836 during the voyage of the Beagle through the Pacific. This theory, founded on the premise of a subsiding volcano and the corresponding upward growth of coral reef, was astonishing for the time considering the absence of an underpinning awareness of plate tectonics. Furthermore, with the exception of the occasional permutation and opposing idea his theory has endured and has an enviable longevity amongst paradigms in geomorphology. In his theory, Darwin emphasised the generally circular morphology of the atoll shape and surprisingly, the validity of this simple morphological premise has never been questioned. There are however, few atolls in the Pacific Ocean that attain such a simple morphology with most manifesting one or more arcuate 'bight-like' structures (ABLSs). These departures from the circular form complicate his simplistic model and are indicative of geomorphological processes in the Pacific Ocean which cannot be ignored. ABLSs represent the surface morphological expression of major submarine failures of atoll volcanic foundations. Such failures can occur during any stage of atoll formation and are a valuable addition to Darwin's theory because they indicate the instability of the volcanic foundations. It is widely recognized in the research community that sector/flank collapses of island edifices are invariably tsunamigenic and yet we have no clear understanding of how significant such events are in the tsunami hazard arena. The recognition of ABLSs however, now offers scientists the opportunity to establish a first order database of potential local and regional tsunamigenic sources associated with the sector/flank collapses of island edifices. We illustrate the talk with examples of arcuate 'bight-like' structures and associated tsunamis in atoll and atoll-like environments. The implications for our understanding of

  6. Atoll stratigraphy as a record of sea level change: Problems and prospects

    NASA Astrophysics Data System (ADS)

    Lincoln, Jonathan M.; Schlanger, Seymour O.

    1991-04-01

    Stratigraphic hiatuses and solution unconformities in the subsurface of Enewetak Atoll, northern Marshall Islands, record periods of atoll emergence during low stands of sea level. Changes in sea level are also recorded in the atoll subsurface by variations in the rate of sediment accumulation relative to the subsidence rate of the underlying volcanic edifice. Past sea levels can be derived from atoll stratigraphy by correcting the present depth of dated subsurface horizons for thermal subsidence and lithospheric flexure since the time of deposition. A correction for depositional paleodepth may also be necessary. As a result of erosion and nondeposition during periods of emergence, the history of sea level derived in this manner is discontinuous. Past sea levels derived from atoll stratigraphy can only be estimated to within ±50 m relative to present sea level owing to uncertainties in the corrections for subsidence and flexure; however, the minimum magnitude of sea level falls estimated from stratigraphic hiatuses can be estimated to within ±10 m. Owing to limited fossil-based age resolution, only long-term sea level trends can be deduced from sediments dated by means of biostratigraphy. Based on the biostratigraphic ages of subsurface horizons at Enewetak, we can discern very little long-term change in sea level from late Eocene through late Oligocene, a rise to ˜110 m above present sea level in the early Miocene, a long-term fall of ˜170 m through middle and late Miocene time, and a long-term rise of ˜60 m from the end of the Miocene to present. Resolution of the sea level history recorded beneath mid-ocean atolls may be improved by determining the age of shallow-marine carbonates by means of strontium isotope stratigraphy. Our interpretation of past sea levels based on 87Sr/86Sr chronostratigraphy from Enewetak confirms the long-term sea level trends inferred from biostratigraphic subsurface ages. In addition, we interpret three Oligocene sea level falls

  7. Incorporating Tsunami Projections to Sea Level Rise Vulnerability Assessments -A Case Study for Midway Atoll-

    NASA Astrophysics Data System (ADS)

    Gica, E.; Reynolds, M.

    2012-12-01

    Recent global models predict a rise of approximately one meter in global sea level by 2100, with potentially larger increases in areas of the Pacific Ocean. If current climate change trends continue, low-lying islands across the globe may become inundated over the next century, placing island biodiversity at risk. Adding to the risk of inundation due to sea level rise is the occurrence of cyclones and tsunamis. This combined trend will affect the low-lying islands of the Northwestern Hawaiian Islands and it is therefore important to assess its impact since these islands are critical habitats to many endangered endemic species and support the largest tropical seabird rookery in the world. The 11 March 2011 Tohoku (Mw=8.8) earthquake-tsunami affected the habitat of many endangered endemic species in Midway Atoll National Wildlife Refuge because all three islands (Sand, Eastern and Spit) were inundated by tsunami waves. At present sea level, some tsunamis from certain source regions would not affect Midway Atoll. For example, the previous earthquake-tsunamis such as the 15 November 2006 Kuril (Mw=8.1) and 13 February 2007 Kuril (Mw=7.9) were not significant enough to affect Midway Atoll. But at higher sea levels, tsunamis with similar characteristics could pose a threat to such terrestrial habitats and wildlife. To visualize projected impacts to vegetation composition, wildlife habitat, and wildlife populations, we explored and analyzed inundation vulnerability for a range of possible sea level rise and tsunami scenarios at Midway Atoll National Wildlife Refuge. Studying the combined threat of tsunamis and sea level rise can provide more accurate and comprehensive assessments of the vulnerability of the unique natural resources on low-lying islands. A passive sea level rise model was used to determine how much inundation will occur at different sea level rise values for the three islands of Midway Atoll and each scenario was coupled with NOAA Center for Tsunami

  8. Relationships between benthic cover, current strength, herbivory, and a fisheries closure in Glovers Reef Atoll, Belize

    NASA Astrophysics Data System (ADS)

    McClanahan, T.; Karnauskas, M.

    2011-03-01

    Benthic cover, current strengths, and fish abundance and diversity were examined on 150 lagoonal patch reefs and mapped to determine their distribution, inter-relationships, and relationship to the fisheries closure in Glovers Reef Atoll. Current strength was highest at both the northern and southern ends of the atoll and largely controlled by local wind and weakly by tidal forcing. Benthic functional group distributions varied throughout the atoll and had distinct areas of dominance. In contrast, dominance of coral species was weaker, reflecting the lost cover and zonation of Acropora, Porites, and Montastraea that were reported in the 1970s. Hard and soft corals dominated the windward rim, while the central and leeward lagoon had lower current strengths and sea grass and fleshy green algae were relatively more abundant. Brown erect algae were relatively more common in the north and calcifying green and red algae the southern ends of the atoll. Only Montastraea- Agaricia agaricites distributions were similar to reports from the 1970s with high relative dominance in the southern and northeast atoll. The central-northern zone, which was described as an Acropora zone in the 1970s, was not recognizable, and Porites porites, P. astreoides, Millepora alcicornis, and Favia fragum were the most abundant species during this survey . Hard and soft coral cover abundance declined away from the reef rim and tidal channels and was associated with fast seawater turnover and high surgeonfish abundance. Consequently, the windward rim area has retained the most original and persistent hard-soft coral and surgeonfish community and is considered a priority for future management, if the goal is to protect coral from fishing impacts.

  9. Dongsha Atoll: A potential thermal refuge for reef-building corals in the South China Sea.

    PubMed

    Tkachenko, Konstantin S; Soong, Keryea

    2017-06-01

    Dongsha Atoll (also known as the Pratas Islands), the northernmost atoll in the South China Sea, experiences two contrasting physical phenomena: repetitive anomalies of the sea surface temperature exceeding the coral bleaching threshold and regular effects of the world's strongest internal waves resulting in the rhythmic upwelling of cold deep waters at the outer reef slopes of the atoll. This unique combination may result in significant differences in coral species composition and structure between the lagoon and forereef. Surveys conducted in August-September 2016 at 12 study sites in the 2-15 m depth range at Dongsha Atoll revealed a clear spatial separation between 'thermally-susceptible' stony coral genera, including Acropora, Pocillopora and Montipora, which mainly inhabited the forereef, and 'thermally-resistant' genera, including massive Porites, foliaceous Echinopora, Pavona and Turbinaria, which mainly resided in the lagoon. The mean coral cover and species richness on the forereef were respectively 1.8 and 1.4 times higher than those in the lagoon (61.3% and 98 species on the forereef vs. 34.2% and 69 species in the lagoon). Coral mortality rates, expressed as the ratio of dead to live stony corals, showed the same pattern (0.4 in the lagoon vs. 0.009 on the forereef). Furthermore, in a laboratory experiment, 'thermally-susceptible' taxa from the lagoon, (e.g. Pocillopora verrucosa and P. damicornis), exhibited higher resistance to bleaching than did their counterparts from the forereef. The present findings indicate that Dongsha Atoll is a potential thermal refuge for reef-building corals in the northern South China Sea and reveal the development of resilience and resistance to bleaching in coral communities of the lagoon. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. 5 CFR 591.402 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Separate Maintenance Allowance for Duty at Johnston Island § 591.402 Definitions. Adult, a term used in the... receiving a similar allowance. Johnston Island, also called Johnston Atoll, is a possession of the United... allowance to assist an employee assigned to Johnston Island who is compelled by reason of dangerous,...

  11. Evaluating hydrologic response to land cover and climate change: An example from the Palmyra Atoll National Wildlife Refuge

    NASA Astrophysics Data System (ADS)

    Lane, J. W.; Briggs, M.; Kulongoski, J. T.; Pollock, A. L.

    2013-12-01

    The Palmyra Atoll National Wildlife Refuge is located in the central Pacific Ocean, about 1,000 miles south of the island of Oahu. Impacts on the atoll's hydrologic and ecologic systems are anticipated from two key anthropogenic drivers of change: (1) eradication of invasive coconut palms and replanting of native Pisonia grandis trees, and (2) global climate change. In the near-term, the palm eradication program is expected to modify the distribution and quality of groundwater proximal to the reforested areas. Longer term, sea level rise, changes in precipitation, and changes in storm frequency and intensity are expected to have a broader impact on the freshwater resources of the atoll. We have initiated a project to characterize current climatic and hydrologic conditions on Palmyra, and monitor changes in order to model baseline conditions and future changes in groundwater distribution. Because rain water harvest satisfies human need on Palmyra, the atoll enables study of groundwater resource change uncomplicated by groundwater pumping stress. Field trips conducted in 2008 and 2013 have included geophysical surveys, weather station upgrades, installation of monitoring wells, and geochemical sampling. Nine wells have been installed on Cooper Island (the largest island of the atoll), each instrumented with a combination of temperature, conductivity, and pressure sensors. Repeated frequency-domain electromagnetic conductivity surveys indicate a reduction in the thickness of the freshwater lens on the southern side of the Cooper Island since 2008, possibly linked to recent modification to the atoll's runway and drainage system. These results indicate that we can successfully capture future transformations induced by land cover and climate changes. The Palmyra Atoll project provides open-source information and insight about human-driven change to the vulnerable freshwater resources of low-lying islands; we hope others will take interest in, and make use of the

  12. Tsunami hazard potential for the equatorial southwestern Pacific atolls of Tokelau from scenario-based simulations

    NASA Astrophysics Data System (ADS)

    Orpin, Alan R.; Rickard, Graham J.; Gerring, Peter K.; Lamarche, Geoffroy

    2016-05-01

    Devastating tsunami over the last decade have significantly heightened awareness of the potential consequences and vulnerability of low-lying Pacific islands and coastal regions. Our appraisal of the potential tsunami hazard for the atolls of the Tokelau Islands is based on a tsunami source-propagation-inundation model using Gerris Flow Solver, adapted from the companion study by Lamarche et al. (2015) for the islands of Wallis and Futuna. We assess whether there is potential for tsunami flooding on any of the village islets from a selection of 14 earthquake-source experiments. These earthquake sources are primarily based on the largest Pacific earthquakes of Mw ≥ 8.1 since 1950 and other large credible sources of tsunami that may impact Tokelau. Earthquake-source location and moment magnitude are related to tsunami-wave amplitudes and tsunami flood depths simulated for each of the three atolls of Tokelau. This approach yields instructive results for a community advisory but is not intended to be fully deterministic. Rather, the underlying aim is to identify credible sources that present the greatest potential to trigger an emergency response. Results from our modelling show that wave fields are channelled by the bathymetry of the Pacific basin in such a way that the swathes of the highest waves sweep immediately northeast of the Tokelau Islands. Our limited simulations suggest that trans-Pacific tsunami from distant earthquake sources to the north of Tokelau pose the most significant inundation threat. In particular, our assumed worst-case scenario for the Kuril Trench generated maximum modelled-wave amplitudes in excess of 1 m, which may last a few hours and include several wave trains. Other sources can impact specific sectors of the atolls, particularly distant earthquakes from Chile and Peru, and regional earthquake sources to the south. Flooding is dependent on the wave orientation and direct alignment to the incoming tsunami. Our "worst-case" tsunami

  13. The Prevalence of Neck and Shoulder Symptoms and Associations with Comorbidities and Disability: The Johnston County Osteoarthritis Project.

    PubMed

    Wright, Anne R; Shi, Xiaoyan A; Busby-Whitehead, Jan; Jordan, Joanne M; Nelson, Amanda E

    Neck and shoulder pain are common but underreported by older people, raising important questions of frequency, medical comorbidities, gender and racial disparities and functional impact associated with neck and shoulder symptoms in elders, which we examined in this analysis. We performed a cross-sectional analysis in the community-based Johnston County Osteoarthritis Project, a cohort that is representative of the U.S. population, utilizing data from 1672 participants with a mean age of 68 years; 69% were white and 68% were women. Trained staff obtained data on participant-reported: symptoms, comorbidities, depression, and functional status; and performance-based functional assessments. Regression models of neck and shoulder symptoms and functional measures were adjusted for age, sex, race, and body mass index, and additionally for other joint symptoms and comorbidities. Symptoms of neck (8%), shoulder (13%) or both (13%) were reported by participants. Neck symptoms were most frequently reported by White women; shoulder symptoms were evenly distributed among race and gender subgroups. Neck and shoulder symptoms were associated with cancer, diabetes mellitus, depression, and lung, cardiovascular, and other musculoskeletal problems, as well as pain, aching or stiffness at other sites, and independently with self-reported and performance -based functional measures. These findings suggest that primary health care providers should inquire about neck and shoulder symptoms and address potential underlying causes to improve functional status and decrease disability in older people.

  14. The Prevalence of Neck and Shoulder Symptoms and Associations with Comorbidities and Disability: The Johnston County Osteoarthritis Project

    PubMed Central

    Wright, Anne R.; Shi, Xiaoyan A.; Busby-Whitehead, Jan; Jordan, Joanne M.; Nelson, Amanda E.

    2015-01-01

    Objectives Neck and shoulder pain are common but underreported by older people, raising important questions of frequency, medical comorbidities, gender and racial disparities and functional impact associated with neck and shoulder symptoms in elders, which we examined in this analysis. Methods We performed a cross-sectional analysis in the community-based Johnston County Osteoarthritis Project, a cohort that is representative of the U.S. population, utilizing data from 1672 participants with a mean age of 68 years; 69% were white and 68% were women. Trained staff obtained data on participant-reported: symptoms, comorbidities, depression, and functional status; and performance-based functional assessments. Regression models of neck and shoulder symptoms and functional measures were adjusted for age, sex, race, and body mass index, and additionally for other joint symptoms and comorbidities. Results Symptoms of neck (8%), shoulder (13%) or both (13%) were reported by participants. Neck symptoms were most frequently reported by White women; shoulder symptoms were evenly distributed among race and gender subgroups. Neck and shoulder symptoms were associated with cancer, diabetes mellitus, depression, and lung, cardiovascular, and other musculoskeletal problems, as well as pain, aching or stiffness at other sites, and independently with self-reported and performance –based functional measures. Conclusions These findings suggest that primary health care providers should inquire about neck and shoulder symptoms and address potential underlying causes to improve functional status and decrease disability in older people. PMID:27651037

  15. The northernmost coral frontier of the Maldives: The coral reefs of Ihavandippolu Atoll under long-term environmental change.

    PubMed

    Tkachenko, Konstantin S

    2012-12-01

    Ihavandippolu, the northernmost atoll of the Maldives, experienced severe coral bleaching and mortality in 1998 followed by several bleaching episodes in the last decade. Coral cover in the 11 study sites surveyed in July-December of 2011 in the 3-5 m depth range varied from 1.7 to 51%. Reefs of the islands located in the center of Ihavandippolu lagoon have exhibited a very low coral recovery since 1998 and remain mostly degraded 12 years after the impact. At the same time, some reefs, especially in the inner part of the eastern ring of the atoll, demonstrate a high coral cover (>40%) with a dominance of branching Acropora that is known to be one of the coral genera that is most susceptible to thermal stress. The last severe bleaching event in 2010 resulted in high coral mortality in some sites of the atoll. Differences in coral mortality rates and proportion between "susceptible" and "resistant" taxa in study sites are apparently related to long-term adaptation and local hydrological features that can mitigate thermal impacts. Abundant herbivorous fish observed in the atoll prevent coral overgrowth by macroalgae even on degraded reefs. Despite the frequent influence of temperature anomalies and having less geomorphologic refuges for coral survivals than other larger Maldivian atolls, a major part of observed coral communities in Ihavandippolu Atoll exhibits high resilience and potential for further acclimatization to a changing environment.

  16. Observations of Water Mass Flux at the North Channel of Dongsha Atoll

    NASA Astrophysics Data System (ADS)

    Yang, J.; Huang, Z. C.

    2016-02-01

    The water flow in Dongsha Atoll is important for biogeochemical and biological status in the atoll lagoon. Here, we present a four-week in-situ measurement of waves and currents to study the water mass flux at the north channel of the atoll. The near-bottom current profiles were measured by one bottom mounted pulse-coherent acoustic Doppler profiler and the turbulent flow motions were measured by two acoustic Doppler velocimeters. The dataset covers two spring-neap cycles where the major solar tide modulated the major lunar tide. The Fourier spectrum analysis is used to obtain the dominant tidal period. The observed current speed is up to 0.5 m/s during the observational period and is obviously at opposite direction between flood and ebb tides. During the flood tide, the current flow is toward the direction of northwest to southeast while it changes to northwestward direction during the ebb tides. The current speed is much larger at the ebb tides than that at flood tides, which indicates that the net water mass flux was not balanced at the north cannel. The observed mean net mass flux is negative (outward the lagoon), which suggests that the water mass was transported throughout the channel from the atoll lagoon. From the mass conservation, the result implies that the south channel or the wave-induced driven current along the barrier reef flat of the atoll may provide a positive net flux to bring the water into the lagoon. However, the value of the mean net mass flux is small, which indicates that the exchange of the water mass between the atoll lagoon system and the adjacent open ocean was largely determined by the tidal currents. The Hilbert-Huang transform is applied to extract the time-varying modes to study the variation of the daily net mass flux. In addition, the local wind is found to affect the local wave height and period though the fetch is limited. The observed wave height and wave period can be predicted well by the SWAN model.

  17. 32 CFR 187.3 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... United States. The territories and possessions of the United States include the Virgin Islands, American Samoa, Wake Island, Midway Island, Guam, Palmyra Island, Johnston Atoll, Navassa Island, and...

  18. 32 CFR 187.3 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... United States. The territories and possessions of the United States include the Virgin Islands, American Samoa, Wake Island, Midway Island, Guam, Palmyra Island, Johnston Atoll, Navassa Island, and...

  19. 32 CFR 187.3 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... United States. The territories and possessions of the United States include the Virgin Islands, American Samoa, Wake Island, Midway Island, Guam, Palmyra Island, Johnston Atoll, Navassa Island, and...

  20. 32 CFR 187.3 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... United States. The territories and possessions of the United States include the Virgin Islands, American Samoa, Wake Island, Midway Island, Guam, Palmyra Island, Johnston Atoll, Navassa Island, and...

  1. 5 CFR 551.104 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...); (6) American Samoa; (7) Guam; (8) Commonwealth of the Northern Mariana Islands; (9) Midway Atoll; (10... Mariana Islands; (9) Midway Atoll; (10) Wake Island; (11) Johnston Island; and (12) Palmyra....

  2. 48 CFR 222.7001 - Definition.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., the Northern Mariana Islands, American Samoa, Guam, the U.S. Virgin Islands, Baker Island, Howland Island, Jarvis Island, Johnston Atoll, Kingman Reef, Midway Islands, Navassa Island, Palmyra Atoll, and Wake Island....

  3. 48 CFR 222.7001 - Definition.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., the Northern Mariana Islands, American Samoa, Guam, the U.S. Virgin Islands, Baker Island, Howland Island, Jarvis Island, Johnston Atoll, Kingman Reef, Midway Islands, Navassa Island, Palmyra Atoll, and Wake Island....

  4. 48 CFR 222.7001 - Definition.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., the Northern Mariana Islands, American Samoa, Guam, the U.S. Virgin Islands, Baker Island, Howland Island, Jarvis Island, Johnston Atoll, Kingman Reef, Midway Islands, Navassa Island, Palmyra Atoll, and Wake Island....

  5. 48 CFR 222.7001 - Definition.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., the Northern Mariana Islands, American Samoa, Guam, the U.S. Virgin Islands, Baker Island, Howland Island, Jarvis Island, Johnston Atoll, Kingman Reef, Midway Islands, Navassa Island, Palmyra Atoll, and Wake Island....

  6. Radiological-dose assessments of atolls in the northern Marshall Islands

    SciTech Connect

    Robison, W.L.

    1983-04-01

    The Marshall Islands in the Equatorial Pacific, specifically Enewetak and Bikini Atolls, were the site of US nuclear testing from 1946 through 1958. In 1978, the Northern Marshall Islands Radiological Survey was conducted to evaluate the radiological conditions of two islands and ten atolls downwind of the proving grounds. The survey included aerial external gamma measurements and collection of soil, terrestrial, and marine samples for radionuclide analysis to determine the radiological dose from all exposure pathways. The methods and models used to estimate doses to a population in an environment where natural processes have acted on the source-term radionuclides for nearly 30 y, data bases developed for the models, and results of the radiological dose analyses are described.

  7. Coralligenous "atolls": discovery of a new morphotype in the Western Mediterranean Sea.

    PubMed

    Bonacorsi, Marina; Pergent-Martini, Christine; Clabaut, Philippe; Pergent, Gérard

    2012-01-01

    Coralligenous habitat and rhodoliths beds are very important in terms of biodiversity in the Mediterranean Sea. During an oceanographic campaign, carried out in northern Cap Corse, new coralligenous structures have been discovered. These structures, never previously identified in the Mediterranean Sea, are named "coralligenous atolls" because of their circular shape. The origin and growth dynamics of these atolls are still unknown but their form does not appear to result from hydrodynamic action and an anthropogenic origin also seems unlikely. However, this kind of shape seems rather closer to that of other circular structures (e.g. pockmarks) the origin of which is related to gaseous emissions. Further studies are needed to confirm this hypothesis through chemical analysis.

  8. Environmental determinants of coral reef fish diversity across several French Polynesian atolls.

    PubMed

    Planes, Serge; Lecchini, David; Mellin, Camille; Charton, José Garcia; Harmelin-Vivien, Mireille; Kulbicki, Michel; Mou-Tham, Gérard; Galzin, René

    2012-06-01

    The present study aimed at exploring the diversity of coral reef fishes in 10 French Polynesian atolls and sought to determine which environmental variables best explain diversity. A total of 136,614 fish belonging to 302 species were recorded in 1995 and 1996. The stepwise multiple regression analysis showed that the best model of variation in species richness (55% of total variation) incorporated three geomorphologic descriptors (atoll perimeter, submerged rim and abundance of pinnacles) and two habitat descriptors (percentage cover of dead coral and sand). The best model of variation in Shannon-Wiener's species diversity index (43% of total variation) included two geomorphologic descriptors (mean depth and level of water exchange) and three habitat descriptors (percentage cover of mud, dead coral and gravel). Overall, our survey recognises the importance of both geomorphologic and habitat descriptors as leading contenders in explaining biodiversity in relation to energy input and habitat area hypothesis.

  9. Biotic control of an abiotic resource: Palmyra Atoll, a case study

    NASA Astrophysics Data System (ADS)

    Engels, M.; Heinse, R.

    2013-12-01

    The availability of abiotic resources as a control on the spatial distribution of plants in an ecosystem is well studied. Less well known is the impact of plants on the availability of abiotic resources and how this biotic control of the environment influences vegetative distribution over time. In order to investigate this question, we examined the influence of vegetation on the water balance of a tropical atoll. Palmyra is a small (2.5 km2) wet atoll in the northern Line Islands that hosts five species of native and introduced trees/shrubs, Cocos nucifera, Pisonia grandis, Tournefortia argentia, Terminalia catappa, and Scaevola sericea, accounting for ~85% percent of the vegetative coverage on the island. Using historical aerial photographs, climate data, published estimates of vegetative cover, and published estimates of transpiration rates we present estimates of the range of vegetative water demand and the change in water demand as influenced by changes in vegetation distribution through time.

  10. Surface and Internal Wave Processes in the Coastal Zone of an Atoll Island

    DTIC Science & Technology

    2015-09-30

    and Lagrangian platforms over the course of a multi-year experiment. A likely focus site is the island of Palau, which poses a significant barrier ...an Atoll Island Mark A. Merrifield 1000 Pope Road, MSB 317 Honolulu, Hawaii 96822 phone: (808) 956-6161 fax: (808) 956-2352 email...current systems, such as the North Equatorial Current (NEC), to smaller scales as flows encounter island and submarine topography characteristic of

  11. Draft Environmental Impact Statement. Proposed Actions at U.S. Army Kwajalein Atoll

    DTIC Science & Technology

    1989-06-01

    gpd) freshwater production facility, including desalination equipment and piping for the seawater intake and the distribution system. The project is...coralline algae, mollusks, echino- derms, foraminiferans, and green sand-producing algae) that secrete external skeletons of calcium and magnesium...representative remnants of native atoll forests. The vascular flora of the 11 islands surveyed comprises 315 species. Fifty-five (17 percent) of these are con

  12. Draft Environmental Impact Statement. Proposed Actions at U.S. Army Kwajalein Atoll

    DTIC Science & Technology

    1989-06-12

    freshwater production facility, including desalination equipment and piping for the seawater intake and the distribution system. The project is budgeted...producing algae) that I secrete external skeletons of calcium and magnesium car- bonates. As these organisms grew and died, their remains were either cemented...of native atoll forests. The vascular flora of the 11 islands surveyed comprises 315 species. Fifty-five (17 percent) of these are con- sidered

  13. The plutonium isotopic composition of marine biota on Enewetak Atoll: a preliminary assessment.

    PubMed

    Hamilton, Terry F; Martinelli, Roger E; Kehl, Steven R; McAninch, Jeffrey E

    2008-10-01

    We have determined the level and distribution of gamma-emitting radionuclides, plutonium activity concentrations, and 240Pu/239Pu atom ratios in tissue samples of giant clam (Tridacna gigas and Hippopus hippopus), a top snail (Trochus nilaticas) and sea cucumber (Holothuria atra) collected from different locations around Enewetak Atoll. The plutonium isotopic measurements were performed using ultra-high sensitivity accelerator mass spectrometry (AMS). Elevated levels of plutonium were observed in the stomachs (includes the stomach lining) of Tridacna clam (0.62 to 2.98 Bq kg(-1), wet wt.), in the soft parts (edible portion) of top snails (0.25 to 1.7 Bq kg(-1)), wet wt.) and, to a lesser extent, in sea cucumber (0.015 to 0.22 Bq kg(-1), wet wt.) relative to muscle tissue concentrations in clam (0.006 to 0.021 Bq kg(-1), wet wt.) and in comparison with previous measurements of plutonium in fish. These data and information provide a basis for re-evaluating the relative significance of dietary intakes of plutonium from marine foods on Enewetak Atoll and, perhaps most importantly, demonstrate that discrete 240Pu239Pu isotope signatures might well provide a useful investigative tool to monitor source-term attribution and consequences on Enewetak Atoll. One potential application of immediate interest is to monitor and assess the health and ecological impacts of leakage of plutonium (as well as other radionuclides) from a low-level radioactive waste repository on Runit Island relative to background levels of fallout contamination in Enewetak Atoll lagoon.

  14. Symbiodinium spp. associated with scleractinian corals from Dongsha Atoll (Pratas), Taiwan, in the South China Sea.

    PubMed

    Keshavmurthy, Shashank; Tang, Kuo-Hsun; Hsu, Chia-Min; Gan, Chai-Hsia; Kuo, Chao-Yang; Soong, Keryea; Chou, Hong-Nong; Chen, Chaolun Allen

    2017-01-01

    Dongsha Atoll (also known as Pratas) in Taiwan is the northernmost atoll in the South China Sea and a designated marine national park since 2007. The marine park's scope of protection covers the bio-resources of its waters in addition to uplands, so it is important to have data logging information and analyses of marine flora and fauna, including their physiology, ecology, and genetics. As part of this effort, we investigated Symbiodinium associations in scleractinian corals from Dongsha Atoll through surveys carried out at two depth ranges (shallow, 1-5 m; and deep, 10-15 m) in 2009 and during a bleaching event in 2010. Symbiodinium composition was assessed using restriction fragment length polymorphism (RFLP) of 28S nuclear large subunit ribosomal DNA (nlsrDNA). Our results showed that the 796 coral samples from seven families and 20 genera collected in 2009 and 132 coral samples from seven families and 12 genera collected in 2010 were associated with Symbiodinium C, D and C+D. Occurrence of clade D in shallow water (24.5%) was higher compared to deep (14.9%). Due to a bleaching event in 2010, up to 80% of coral species associated with Symbiodinium C underwent moderate to severe bleaching. Using the fine resolution technique of denaturing gradient gel electrophoresis (DGGE) of internal transcribed spacer 2 (ITS2) in 175 randomly selected coral samples, from 2009 and 2010, eight Symbiodinium C types and two Symbiodinium D types were detected. This study is the first baseline survey on Symbiodinium associations in the corals of Dongsha Atoll in the South China Sea, and it shows the dominance of Symbiodinium clade C in the population.

  15. Symbiodinium spp. associated with scleractinian corals from Dongsha Atoll (Pratas), Taiwan, in the South China Sea

    PubMed Central

    Tang, Kuo-Hsun; Hsu, Chia-Min; Gan, Chai-Hsia; Kuo, Chao-Yang; Soong, Keryea; Chou, Hong-Nong

    2017-01-01

    Dongsha Atoll (also known as Pratas) in Taiwan is the northernmost atoll in the South China Sea and a designated marine national park since 2007. The marine park’s scope of protection covers the bio-resources of its waters in addition to uplands, so it is important to have data logging information and analyses of marine flora and fauna, including their physiology, ecology, and genetics. As part of this effort, we investigated Symbiodinium associations in scleractinian corals from Dongsha Atoll through surveys carried out at two depth ranges (shallow, 1–5 m; and deep, 10–15 m) in 2009 and during a bleaching event in 2010. Symbiodinium composition was assessed using restriction fragment length polymorphism (RFLP) of 28S nuclear large subunit ribosomal DNA (nlsrDNA). Our results showed that the 796 coral samples from seven families and 20 genera collected in 2009 and 132 coral samples from seven families and 12 genera collected in 2010 were associated with Symbiodinium C, D and C+D. Occurrence of clade D in shallow water (24.5%) was higher compared to deep (14.9%). Due to a bleaching event in 2010, up to 80% of coral species associated with Symbiodinium C underwent moderate to severe bleaching. Using the fine resolution technique of denaturing gradient gel electrophoresis (DGGE) of internal transcribed spacer 2 (ITS2) in 175 randomly selected coral samples, from 2009 and 2010, eight Symbiodinium C types and two Symbiodinium D types were detected. This study is the first baseline survey on Symbiodinium associations in the corals of Dongsha Atoll in the South China Sea, and it shows the dominance of Symbiodinium clade C in the population. PMID:28133566

  16. Meteorological Monitoring on bikini atoll: system description and data summary (May 2000 - April 2001)

    SciTech Connect

    Gouveia F; Bradsher, R; Brunk, J; Hamilton, T

    2002-01-01

    Meteorological data are continuously collected at three sites on Bikini Atoll in support of radioecological research and monitoring programs conducted by the Health and Ecological Assessments Division at the Lawrence Livermore National Laboratory (LLNL). Weather stations were first established on Bikini Atoll in April 1990, and provide information on rainfall, wind speed and direction, air temperature, humidity, and solar radiation. These data and information are used to interpret results of remediation experiments designed to evaluate the effectiveness of potassium fertilizer on reducing the uptake of {sup 137}Cs into locally grown foods. We have also demonstrated that {sup 137}Cs is slowly leached from surface soil by the action of rain water. Long-term meteorological data are crucial to our efforts of developing an understanding of environmental processes controlling the environment loss of {sup 137}Cs in coral atoll soil. In May 2000, older data collection platforms and the DOS-based system that downloaded data from National Oceanic & Atmospheric Administration (NOAA)'s Data Automatic Processing System (DAPS) was decommissioned, and new data loggers, GOES (Geostationary Operational Environmental Satellite) transmitters and antennas were installed. Consequently, new procedures were developed to maintain the field systems, download the data, and reduce and archive the data. This document provides an operational description and status report on the three new meteorological monitoring systems on Bikini Atoll as well as an computational summary of previously recorded data. Included are overviews of procedures for sensor exchange, data recovery and reduction, and specific information about the different sensors. We also provide a description of systems maintenance and trouble shooting activities. This report will be updated on an annual basis.

  17. Marshall Islands Fringing Reef and Atoll Lagoon Observations of the Tohoku Tsunami

    NASA Astrophysics Data System (ADS)

    Ford, Murray; Becker, Janet M.; Merrifield, Mark A.; Song, Y. Tony

    2014-12-01

    The magnitude 9.0 Tohoku earthquake on 11 March 2011 generated a tsunami which caused significant impacts throughout the Pacific Ocean. A description of the tsunami within the lagoons and on the surrounding fringing reefs of two mid-ocean atoll islands is presented using bottom pressure observations from the Majuro and Kwajalein atolls in the Marshall Islands, supplemented by tide gauge data in the lagoons and by numerical model simulations in the deep ocean. Although the initial wave arrival was not captured by the pressure sensors, subsequent oscillations on the reef face resemble the deep ocean tsunami signal simulated by two numerical models, suggesting that the tsunami amplitudes over the atoll outer reefs are similar to that in deep water. In contrast, tsunami oscillations in the lagoon are more energetic and long lasting than observed on the reefs or modelled in the deep ocean. The tsunami energy in the Majuro lagoon exhibits persistent peaks in the 30 and 60 min period bands that suggest the excitation of closed and open basin normal modes, while energy in the Kwajalein lagoon spans a broader range of frequencies with weaker, multiple peaks than observed at Majuro, which may be associated with the tsunami behavior within the more irregular geometry of the Kwajalein lagoon. The propagation of the tsunami across the reef flats is shown to be tidally dependent, with amplitudes increasing/decreasing shoreward at high/low tide. The impact of the tsunami on the Marshall Islands was reduced due to the coincidence of peak wave amplitudes with low tide; however, the observed wave amplitudes, particularly in the atoll lagoon, would have led to inundation at different tidal phases.

  18. Ecological risk assessments for protected migratory birds and marine species at Midway Atoll

    SciTech Connect

    Scatolini, S.; Hope, B.; Lees, D.

    1995-12-31

    In June 1997, the US Navy plans to close its Naval Air Facility on Sand Island and transfer the atoll to the US Fish and Wildlife Service for use as a National Wildlife Refuge. Midway provides breeding and feeding habitat for migratory seabirds, terrestrial and marine mammals, sea turtles and other reptiles, and a variety of reef fishes and invertebrates. As part of the base closure and transfer process, 36 sites of potential environmental concern were identified on Sand and Eastern islands. These sites include landfills and uncontrolled disposal areas, hazardous materials storage areas, abandoned transformers, sewer outfalls, and other potential hazardous waste sites. Potential contaminants include pesticides, PAHs, PCBs, and heavy metals. A screening ecological risk assessment was performed at each site with a goal of determining whether contaminants could pose any current or future risks to protected migratory bird or marine mammal wildlife species. Specific exposure pathways investigated were dermal and inhalation routes for ground-nesting and burrowing seabirds; incidental soil ingestion for shore birds; consumption for monk seals and sea turtles. Exposure analysis involved sediment and soil chemistry, marine invertebrate tissue chemistry, bioassays (bioavailability), and food web modeling. Effects analysis involved benthic infauna community analysis, acute and chronic invertebrate sediment bioassays, and extensive literature reviews. Risk characterization used both toxicity quotient methods and weight-of-evidence analysis. Because work by other investigators suggests that birds and perhaps marine wildlife acquire significant contaminant loads while feeding away from the atoll, on-atoll risk investigations had to consider whether atoll sites made significant marginal contributions to existing contaminant loads, particularly with respect to PCBs.

  19. Long-distance dispersal of the coconut palm by migration within the coral atoll ecosystem

    PubMed Central

    Harries, Hugh C.; Clement, Charles R.

    2014-01-01

    Background The location of the original home of the coconut palm, Cocos nucifera, and the extent of its natural dispersal are not known. Proponents of a South American origin must explain why it is not indigenous there and why it shows greatest diversity in southern Asia. Conversely, proponents of an Asian origin must explain why there are no Asian Cocoseae and why the closest botanical relative to Cocos is in South America. Both hypotheses share the common problems of how, when, where and in what directions long-distance dispersal occurred. Hypothesis These difficulties are resolved by accepting that C. nucifera originated and dispersed by populating emerging islands of the coral atoll ecosystem, where establishment conditions impose high selection pressures for survival. When lifted by wave action onto virtually sterile, soilless coralline rocks just above sea level and exposed to the full impact of the sun, seednuts must germinate, root and establish vigorous populations. The cavity within the nut augments the buoyancy provided by the thick husk, which in turn protects the embryo and, by delaying germination, simultaneously extends viability while floating and provides a moisture-retentive rooting medium for the young seedling. These adaptations allow coconuts to disperse widely through the coral atoll ecosystem. Conclusions The monthly production of fruit and the long floating duration ensure that viable seednuts are always available in the lagoon to replace those destroyed by hurricanes and tsunamis, or to populate newly emerged coral atolls elsewhere. Long-distance dispersal is secondary, because it was the spontaneous, independent migration of coral polyps on a prolonged geological time scale that generated new coral atolls in new areas where the coconuts would be amongst the earliest inhabitants. The coconut palm became an intermittent, itinerant, pioneer endemic there, and also on suitable beaches on volcanic or large islands and continental coastlines

  20. Long-distance dispersal of the coconut palm by migration within the coral atoll ecosystem.

    PubMed

    Harries, Hugh C; Clement, Charles R

    2014-03-01

    The location of the original home of the coconut palm, Cocos nucifera, and the extent of its natural dispersal are not known. Proponents of a South American origin must explain why it is not indigenous there and why it shows greatest diversity in southern Asia. Conversely, proponents of an Asian origin must explain why there are no Asian Cocoseae and why the closest botanical relative to Cocos is in South America. Both hypotheses share the common problems of how, when, where and in what directions long-distance dispersal occurred. These difficulties are resolved by accepting that C. nucifera originated and dispersed by populating emerging islands of the coral atoll ecosystem, where establishment conditions impose high selection pressures for survival. When lifted by wave action onto virtually sterile, soilless coralline rocks just above sea level and exposed to the full impact of the sun, seednuts must germinate, root and establish vigorous populations. The cavity within the nut augments the buoyancy provided by the thick husk, which in turn protects the embryo and, by delaying germination, simultaneously extends viability while floating and provides a moisture-retentive rooting medium for the young seedling. These adaptations allow coconuts to disperse widely through the coral atoll ecosystem. The monthly production of fruit and the long floating duration ensure that viable seednuts are always available in the lagoon to replace those destroyed by hurricanes and tsunamis, or to populate newly emerged coral atolls elsewhere. Long-distance dispersal is secondary, because it was the spontaneous, independent migration of coral polyps on a prolonged geological time scale that generated new coral atolls in new areas where the coconuts would be amongst the earliest inhabitants. The coconut palm became an intermittent, itinerant, pioneer endemic there, and also on suitable beaches on volcanic or large islands and continental coastlines.

  1. Reef-island topography and the vulnerability of atolls to sea-level rise

    NASA Astrophysics Data System (ADS)

    Woodroffe, Colin D.

    2008-05-01

    Low-lying reef islands on the rim of atolls are perceived as particularly vulnerable to the impacts of sea-level rise. Three effects are inferred: erosion of the shoreline, inundation of low-lying areas, and saline intrusion into the freshwater lens. Regional reconstruction of sea-level trends, supplementing the short observational instrumental record, indicates that monthly mean sea level is rising in the eastern Indian and western Pacific Oceans. This paper reviews the morphology and substrate characteristics of reef islands on Indo-Pacific atolls, and summarises their topography. On most atolls across this region, there is an oceanward ridge built by waves to a height of around 3 m above MSL; in a few cases these are topped by wind-blown dunes. The prominence of these ridges, together with radiocarbon dating and multi-temporal studies of shoreline position, indicate net accretion rather than long-term erosion on most of these oceanward shores. Less prominent lagoonward ridges occur, but their morphology and continuity are atoll-specific, being a function of the processes operating in each lagoon. Low-lying central areas are a feature of many islands, often locally excavated for production of taro. These lower-lying areas are already subject to inundation, which seems certain to increase as the sea rises. Tropical storms play an important role in the geomorphology of reef islands in those regions where they are experienced. Topographical differences, as well as features such as emergence of the reef flat and the stability of the substrate, mean that islands differ in terms of their susceptibility to sea-level rise. Further assessment of variations in shoreline vulnerability based on topography and substrate could form the basis for enhancing the natural resilience of these islands.

  2. Mass mortality events in atoll lagoons: environmental control and increased future vulnerability.

    PubMed

    Andréfouët, Serge; Dutheil, Cyril; Menkes, Christophe E; Bador, Margot; Lengaigne, Matthieu

    2015-01-01

    Coral reefs and lagoons worldwide are vulnerable environments. However, specific geomorphological reef types (fringing, barrier, atoll, bank for the main ones) can be vulnerable to specific disturbances that will not affect most other reefs. This has implications for local management and science priorities. Several geomorphologically closed atolls of the Pacific Ocean have experienced in recent decades mass benthic and pelagic lagoonal life mortalities, likely triggered by unusually calm weather conditions lasting for several weeks. These events, although poorly known, reported, and characterized, pose a major threat for resource sustainability. Based on a sample of eleven events on eight atolls from the central South Pacific occurring between 1993 and 2012, the conservative environmental thresholds required to trigger such events are identified using sea surface temperature, significant wave height and wind stress satellite data. Using these thresholds, spatial maps of potential risk are produced for the central South Pacific region, with the highest risk zone lying north of Tuamotu Archipelago. A regional climate model, which risk map compares well with observations over the recent period (r=0.97), is then used to downscale the projected future climate. This allows us to estimate the potential change in risk by the end of the 21st century and highlights a relative risk increase of up to 60% for the eastern Tuamotu atolls. However, the small sample size used to train the analysis led to the identification of conservative thresholds that overestimated the observed risk. The results of this study suggest that long-term monitoring of the biophysical conditions of the lagoons at risk would enable more precise identification of the physical thresholds and better understanding of the biological processes involved in these rare, but consequential, mass mortality events. © 2014 John Wiley & Sons Ltd.

  3. Rickettsial Pathogens and Arthropod Vectors of Medical and Veterinary Significance on Kwajalein Atoll and Wake Island

    DTIC Science & Technology

    2012-01-01

    Micronesia. Proceedings of the Entomological Society of Washington 74: 184. Received 17 June 2011, revised 28 Sep. 2011 Reeves et al.: Rickettsial pathogens in Kwajalein and Wake 113 ...B. B. 1972. Insects and other Arthropods from Kwajalein Atoll (Marshall Islands). Proceedings of the Hawaiian Entomological Society 21: 273 – 286...C. Reeves, & T. Aarons. 1948. Aedes aegypti on Wake Island. Pro- ceedings of the Hawaiian Entomological Society 13: 255 – 256. Shaw E. S., J. D

  4. Capabilities of three satellite images to map coral reefs at Dong-Sha Atoll

    NASA Astrophysics Data System (ADS)

    Chen, Jianyu; Mao, Zhihua; Pan, Delu; He, Xianqiang

    2006-12-01

    Coral reefs are complex marine ecosystems and environment-sensitive that are constructed and maintained by biological communities that thrive in the warm tropical ocean. Remote sensing provides a more efficient way to observe and monitor shallow coral reefs than alternative field survey. Dong-Sha Atoll is located at the northern continental margin of the South China Sea. The area of the atoll is more than 300 km2 with an average depth of 10 m, and has being abused by destructive fishing during recent decades. In this paper, three satellite broadband multi-spectral imageries (Quickbird2, ETM+, and SPOT5) are used to survey this area. In the preprocessing, low-resolution images are geometrically corrected to high-resolution imagery. For information extraction, unsupervised classification functions are adopted for ETM+ and SPOT5 data, and supervised classification method for Quickbird2. The classification results are (or not) merged into coral reef, and operated by vectorization, simplification, and topological analysis. There are 1331 coral reefs larger than 100 m2 with the detection limitation of 3×3 pixels at multi-band data of Quickbird2. The results extracted from SPOT5 data are better than that of ETM data at silty lagoon due to its higher resolution, and less at atoll reef bodies in the absence of blue waveband.

  5. Observation of Kilohertz Quasiperiodic Oscillations from the Atoll Source 4U 1702-429 by RXTE

    NASA Technical Reports Server (NTRS)

    Markwardt, C. B.; Strohmayer, Tod E.; Swank, Jean H.

    1998-01-01

    We present results of Rossi X-Ray Timing Explorer (RXTE) observations of the atoll source 4U 1702-429 in the middle of its luminosity range. Kilohertz-range quasiperiodic oscillations (QPOS) were observed first as a narrow (FWHM approximately 7 Hz) peak near 900 Hz, and later as a pair consisting of a narrow peak in the range 625 825 Hz and a faint broad (FWHM 91 Hz) peak. When the two peaks appeared simultaneously the separation was 333 +/- 5 Hz. Six type I thermonuclear bursts were detected, of which five exhibited almost coherent oscillations near 330 Hz, which makes 4U 1702-429 only the second source to show burst oscillations very close to the kilohertz QPO separation frequency. The energy spectrum and color-color diagram indicate that the source executed variations in the range between the "island" and "lower banana" atoll states. In addition to the kilohertz variability, oscillations at approximately 10, approximately 35, and 80 Hz were also detected at various times, superimposed on a red noise continuum. The centroid of the approximately 35 Hz QPO tracks the frequency of the kilohertz oscillation when they were both present. A Lense-Thirring gravitomagnetic precession interpretation appears more plausible in this case, compared to other atoll sources with low frequency QPOs.

  6. Reef fishes have higher parasite richness at unfished Palmyra Atoll compared to fished Kiritimati Island.

    PubMed

    Lafferty, Kevin D; Shaw, Jenny C; Kuris, Armand M

    2008-09-01

    We compared parasite communities at two coral atolls in the Line Islands chain of the central Pacific (Kiritimati Island and Palmyra Atoll). Palmyra Atoll is relatively pristine while Kiritimati Island is heavily fished. At each island, we sampled five fish species for helminth and arthropod endoparasites: Chromis margaritifer, Plectroglyphidodon dickii, Paracirrhites arcatus, Acanthurus nigricans, and Lutjanus bohar. The surveys found monogeneans, digeneans, cestodes, nematodes, acanthocephalans, and copepods. Parasite richness was higher at Palmyra compared to Kiritimati for all five fish species. Fishes from Palmyra also tended to have more parasites species per host, higher parasite prevalence, and higher parasite abundance than did fishes from Kiritimati. The lower parasitism at Kiritimati may result from a simplified food web due to over fishing. Low biodiversity could impair parasite transmission by reducing the availability of hosts required by parasites with complex life cycles. Most notably, the lower abundances of larval shark tapeworms at Kiritimati presumably reflect the fact that fishing has greatly depleted sharks there in comparison to Palmyra.

  7. Reef fishes have higher parasite richness at unfished Palmyra Atoll compared to fished Kiritimati Island

    USGS Publications Warehouse

    Lafferty, Kevin D.; Shaw, Jenny C.; Kuris, Armand M.

    2008-01-01

    We compared parasite communities at two coral atolls in the Line Islands chain of the central Pacific (Kiritimati Island and Palmyra Atoll). Palmyra Atoll is relatively pristine while Kiritimati Island is heavily fished. At each island, we sampled five fish species for helminth and arthropod endoparasites: Chromis margaritifer, Plectroglyphidodon dickii,Paracirrhites arcatus, Acanthurus nigricans, and Lutjanus bohar. The surveys found monogeneans, digeneans, cestodes, nematodes, acanthocephalans, and copepods. Parasite richness was higher at Palmyra compared to Kiritimati for all five fish species. Fishes from Palmyra also tended to have more parasites species per host, higher parasite prevalence, and higher parasite abundance than did fishes from Kiritimati. The lower parasitism at Kiritimati may result from a simplified food web due to over fishing. Low biodiversity could impair parasite transmission by reducing the availability of hosts required by parasites with complex life cycles. Most notably, the lower abundances of larval shark tapeworms at Kiritimati presumably reflect the fact that fishing has greatly depleted sharks there in comparison to Palmyra.

  8. The Role of Intra-Island Temperature Variability at Palmyra Atoll in Mass Coral Bleaching Events

    NASA Astrophysics Data System (ADS)

    Urmy, S.; McNally, J.; Bartz, J.; Dunbar, R.

    2008-12-01

    Mass coral bleaching events have been reported in Palmyra Atoll during severe El Niños in the last 30 years, and are thought to be increasing both in frequency and magnitude. During these events, bleaching is highly localized, with some parts of the reef showing a much greater effect than others. NOAA's Coral Reef Watch monitors thermal stress on corals by calculating degree heating weeks (DHW) from satellite sea surface temperature in a 50 km pixel around each reef group or atoll of interest. While this technique allows some predictive capacity, especially for mass bleaching events, it does not consider the effects of reef geometry on bleaching susceptibility at different reef groups (Hoeke et al., 2006). Furthermore, because of its large scale, it cannot differentiate between open ocean, backreef, or lagoon temperatures. This project compiles high resolution temperature time series recorded in situ at a number of locations on the reef at Palmyra from 2002-2008, with surprising results. At any one given time, corals at different locations around the atoll may be experiencing temperature stresses that are significantly different both between locations and from the satellite DHW product. Shallow reef flats appear to be a source of heated water that, if advected elsewhere on the reef, may stress corals in normally cooler locations. A more thorough understanding of these mechanisms could improve our predictive capability as to which areas of the reef are at greatest risk if mass bleaching events continue to increase in severity and frequency.

  9. Atoll island hydrogeology: flow and freshwater occurrence in a tidally dominated system

    NASA Astrophysics Data System (ADS)

    Oberdorfer, June A.; Hogan, Patrick J.; Buddemeier, Robert W.

    1990-12-01

    A layered-aquifer model of groundwater occurrence in an atoll island was tested with a solute-transport numerical model. The computer model used, SUTRA, incorporates density-dependent flow. This can be significant in freshwater-saltwater interactions associated with the freshwater lens of an atoll island. Boundary conditions for the model included ocean and lagoon tidal variations. The model was calibrated to field data from Enjebi Island, Enewetak Atoll, and tested for sensitivity to a variety of parameters. This resulted in a hydraulic conductivity of 10 m day -1 for the surficial aquifer and 1000 m day -1 for the deeper aquifer; this combination of values gave an excellent reproduction of the tidal response data from test wells. The average salinity distribution was closely reproduced using a dispersivity of 0.02m. The computer simulation quantitatively supports the layered-aquifer model, including under conditions of density-dependent flow, and shows that tidal variations are the predominant driving force for flow beneath the island. The oscillating, vertical flow produced by the tidal variations creates an extensive mixing zone of brackish water. The layered-aquifer model with tidally driven flow is a significant improvement over the Ghyben-Herzberg-Dupuit model as it is conventionally applied to groundwater studies for many Pacific reef islands.

  10. The history of Post-Miocene sea level change: Inferences from stratigraphic modeling of Enewetak Atoll

    NASA Astrophysics Data System (ADS)

    Quinn, Terrence M.

    1991-04-01

    The history of post-Miocene sea level change has been investigated using a quantitative, one-dimensional stratigraphic forward model. The stratigraphic model produces synthetic stratigraphies, including mineralogy and sediment age versus depth, in response to changes in sea level, subsidence, sedimentation, and diagenesis. Model outputs, using sea level curves inferred from passive margin sequence stratigraphy and deep-sea foraminiferal oxygen isotope stratigraphy, were compared to the post-Miocene stratigraphy of Enewetak Atoll. Modeling results support high-frequency (104 to 105 years) fluctuations of post-Miocene sea level. Post-Miocene sea level elevations significantly greater than modern sea level elevation are not easily reconciled with the stratigraphy of Enewetak Atoll. Model/data fit is maximized when a rapid subsidence rate for Enewetak Atoll is used. Alternatively, model/data fit may be maximized using a lower subsidence rate for Enewetak and having post-Miocene sea level elevations significantly lower than modem sea level elevation. Given the present state of knowledge, much work is still needed to accurately decipher the record of post-Miocene sea level change.

  11. A layered aquifer model of atoll island hydrology: Validation of a computer simulation

    NASA Astrophysics Data System (ADS)

    Herman, Marc E.; Buddemeier, Robert W.; Wheatcraft, Stephen W.

    1986-05-01

    The finite-element model FEMWATER was used to simulate groundwater movement in the two-dimensional vertical plane of an atoll island section. The model island had dimensions consistent with Enjebi Island (Enewetak Atoll), a surficial (Holocene) aquifer to a depth of 15m with hydraulic conductivity = 6.9 × 10 -4 ms -1, overlying a (Plio-Pleistocene) aquifer with K = 6.9 × 10 -2 ms -1. A tidally varying water level was applied to the ocean and lagoon boundaries, and the model was run until pseudo steady-state conditions were achieved in the groundwater variations. Hydraulic head contours in the vertical section demonstrate that water motion under the supratidal portion of the island is almost exclusively vertical. Calculated water table tidal lags and efficiencies are in excellent agreement with measured values from shallow wells on Enjebi Island, confirming the validity of the layered aquifer model and the approximate magnitudes of the hydraulic conductivities. Model results near island margins can be interpreted to explain other features of hydrologic field data from atoll islands. The results emphasize the potential importance of tidal effects and vertical water flow on reef island groundwater systems, and cast doubt on the utility of traditional models using the Dupuit assumptions of essentially horizontal flow.

  12. Identification of novel vibration- and deflection-sensitive neuronal subgroups in Johnston's organ of the fruit fly

    PubMed Central

    Matsuo, Eriko; Yamada, Daichi; Ishikawa, Yuki; Asai, Tomonori; Ishimoto, Hiroshi; Kamikouchi, Azusa

    2014-01-01

    The fruit fly Drosophila melanogaster responds behaviorally to sound, gravity, and wind. Johnston's organ (JO) at the antennal base serves as a sensory organ in the fruit fly to detect these mechanosensory stimuli. Among the five anatomically defined subgroups of sensory neurons in JO, subgroups A and B detect sound vibrations and subgroups C and E respond to static deflections, such as gravity and wind. The functions of subgroup-D JO neurons, however, remain unknown. In this study, we used molecular-genetic methods to explore the physiologic properties of subgroup-D JO neurons. Both vibrations and static deflection of the antennal receiver activated subgroup-D JO neurons. This finding clearly revealed that zone D in the antennal mechanosensory and motor center (AMMC), the projection target of subgroup-D JO neurons, is a primary center for antennal vibrations and deflection in the fly brain. We anatomically identified two types of interneurons downstream of subgroup-D JO neurons, AMMC local neurons (AMMC LNs), and AMMC D1 neurons. AMMC LNs are local neurons whose projections are confined within the AMMC, connecting zones B and D. On the other hand, AMMC D1 neurons have both local dendritic arborizations within the AMMC and descending projections to the thoracic ganglia, suggesting that AMMC D1 neurons are likely to relay information of the antennal movement detected by subgroup-D JO neurons from the AMMC directly to the thorax. Together, these findings provide a neural basis for how JO and its brain targets encode information of complex movements of the fruit fly antenna. PMID:24847281

  13. Differences in radiographic features of knee osteoarthritis in African-Americans and Caucasians: the Johnston County Osteoarthritis Project

    PubMed Central

    Braga, L.; Renner, J. B.; Schwartz, T. A.; Woodard, J.; Helmick, C. G.; Hochberg, M. C.; Jordan, J. M.

    2013-01-01

    Summary Objective To examine racial differences in tibiofemoral joint (TFJ) and patellofemoral joint (PFJ) radiographic osteoarthritis in African-American (AA) and Caucasian men and women. Method Multiple logistic regression was used to evaluate cross-sectional associations between race and tibiofemoral osteoarthritis (TF-OA) and the presence, severity and location of individual radiographic features of tibiofemoral joint osteoarthritis [TFJ-OA] (osteophytes, joint space narrowing [JSN], sclerosis and cysts) and patellofemoral joint osteoarthritis (PFJ-OA) (osteophytes, JSN and sclerosis), using data from the Johnston County Osteoarthritis Project. Proportional odds ratios (POR) assessed severity of TF-OA, TFJ and PFJ osteophytes, and JSN, adjusting for confounders. Generalized estimating equations accounted for auto-correlation of knees. Results Among 3187 participants (32.5% AAs; 62% women; mean age 62 years), 6300 TFJ and 1957 PFJ were included. Compared to Caucasians, AA men were more likely to have TF-OA (adjusted odds ratio [aOR] = 1.36; 95% CI, 1.00–1.86); tri-compartmental TFJ and PFJ osteophytes (aOR = 3.06; 95%CI = 1.96–4.78), and TFJ and PFJ sclerosis. AA women were more likely than Caucasian to have medial TFJ and tri-compartmental osteophytes (aOR = 2.13; 1.55–2.94), and lateral TFJ sclerosis. AAs had more severe TF-OA than Caucasians (adjusted cumulative odds ratio [aPOR] = 2.08; 95% CI, 1.19–3.64 for men; aPOR = 1.56; 95% CI, 1.06–2.29 for women) and were more likely to have lateral TFJ JSN. Conclusions Compared to Caucasians, AAs were more likely to have more severe TF-OA; tri-compartmental disease; and lateral JSN. Further research to clarify the discrepancy between radiographic features in OA among races appears warranted. PMID:19735758

  14. US Air Force installation restoration program: Remedial investigation of former herbicide storage site at Johnston Island, Pacific Ocean

    SciTech Connect

    Not Available

    1988-09-01

    This report represents a synthesis and reformatting of six primary documents and other related materials on soils, ocean sediments, air, and biota investigations conducted at Johnston Island (JI), Pacific Ocean, to characterize contamination resulting from storage of 1.37 million gallons of Herbicide Orange (HO) from 1972 through 1977. The individual study components comprise the Remedial Investigation (RI) of the former HO storage site at JI. This report describes the procedures, results, and conclusions of the sampling and analysis programs conducted at JI. Samples of site soils, ocean sediments, airborne particulates, dust, sweepings, and aquatic organisms were collected and analyzed for HO-derived 2,4-dichlorophenoxyacetic acid (2,4-D), 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), and 2,3,7,8- tetrachlorodibenzo-p-dioxin (TCDD). Environmental media other than soils at the storage facility itself were found to be free of contamination or to contain very low contaminant concentrations. No contamination was found in ocean sediments, indicating possible dispersion of contaminants due to erosion. A few of the biological specimens collected were found to contain TCDD levels below the guidelines of 25 to 50 parts per trillion established by the US Food and Drug Administration; TCDD in all other biota samples was nondetectable. Analysis of samples of airborne particulates and of soils, dust, and sweepings from high-use and residential areas outside the boundaries of the former storage site indicated that there is little or no concern of adverse impacts from airborne transport and deposition of TCDD.

  15. Identification of novel vibration- and deflection-sensitive neuronal subgroups in Johnston's organ of the fruit fly.

    PubMed

    Matsuo, Eriko; Yamada, Daichi; Ishikawa, Yuki; Asai, Tomonori; Ishimoto, Hiroshi; Kamikouchi, Azusa

    2014-01-01

    The fruit fly Drosophila melanogaster responds behaviorally to sound, gravity, and wind. Johnston's organ (JO) at the antennal base serves as a sensory organ in the fruit fly to detect these mechanosensory stimuli. Among the five anatomically defined subgroups of sensory neurons in JO, subgroups A and B detect sound vibrations and subgroups C and E respond to static deflections, such as gravity and wind. The functions of subgroup-D JO neurons, however, remain unknown. In this study, we used molecular-genetic methods to explore the physiologic properties of subgroup-D JO neurons. Both vibrations and static deflection of the antennal receiver activated subgroup-D JO neurons. This finding clearly revealed that zone D in the antennal mechanosensory and motor center (AMMC), the projection target of subgroup-D JO neurons, is a primary center for antennal vibrations and deflection in the fly brain. We anatomically identified two types of interneurons downstream of subgroup-D JO neurons, AMMC local neurons (AMMC LNs), and AMMC D1 neurons. AMMC LNs are local neurons whose projections are confined within the AMMC, connecting zones B and D. On the other hand, AMMC D1 neurons have both local dendritic arborizations within the AMMC and descending projections to the thoracic ganglia, suggesting that AMMC D1 neurons are likely to relay information of the antennal movement detected by subgroup-D JO neurons from the AMMC directly to the thorax. Together, these findings provide a neural basis for how JO and its brain targets encode information of complex movements of the fruit fly antenna.

  16. Lumbar spine radiographic features and demographic, clinical, and radiographic knee, hip and hand osteoarthritis: The Johnston County Osteoarthritis Project

    PubMed Central

    Goode, Adam P.; Marshall, Stephen W.; Renner, Jordan B.; Carey, Timothy S.; Kraus, Virginia B.; Irwin, Debra E.; Stürmer, Til; Jordan, Joanne M.

    2012-01-01

    Objective 1) To determine the prevalence of lumbar spine individual radiographic features (IRF) of disc space narrowing (DSN), osteophytes (OST) and facet joint osteoarthritis (FOA). 2) To describe the frequencies of demographic, clinic and radiographic knee, hip and hand osteoarthritis (OA) across lumbar spine IRF. 3) To determine factors associated with lumbar spine IRF. Methods A cross-sectional study of 840 participants enrolled in the Johnston County OA Project (2003-4). Sample-based prevalence estimates were generated for each lumbar spine IRF. Associations between lumbar spine IRF and demographic, clinical and peripheral joint OA were determined with logistic regression models. Results Sample-based prevalence estimates were similar for DSN (57.6%) and FOA (57.9%) but higher for OST (88.1%) with significant differences across race and gender. Hand and knee OA frequencies increased across IRF whereas the effect was absent for hip OA. African Americans had lower odds of FOA (adjusted odds ratio [aOR]=0.45 (95% CI 0.32, 0.62)) while there was no racial association with DSN and OST. Low back symptoms were associated with DSN (aOR=1.37 (95% CI 1.04, 1.80)) but not OST or FOA. Knee OA was associated with OST (aOR=1.62 (95% CI 1.16, 2.27)) and FOA (aOR=1.69 (95% CI 1.15, 2.49)) but not DSN. Hand OA was associated with FOA (aOR=1.67 (95% CI 1.20, 2.28)) but not with DSN or OST. No associations were found with hip OA. Conclusion These findings underscore the importance of analyzing lumbar spine IRF separately as the associations with demographic, clinic and radiographic knee, hip and hand OA differ widely. PMID:22556059

  17. Associations of educational attainment, occupation and community poverty with knee osteoarthritis in the Johnston County (North Carolina) osteoarthritis project.

    PubMed

    Callahan, Leigh F; Cleveland, Rebecca J; Shreffler, Jack; Schwartz, Todd A; Schoster, Britta; Randolph, Randy; Renner, Jordan B; Jordan, Joanne M

    2011-01-01

    The purpose of this study was to examine data from the Johnston County Osteoarthritis (OA) Project for independent associations of educational attainment, occupation and community poverty with tibiofemoral knee OA. A cross-sectional analysis was conducted on 3,591 individuals (66% Caucasian and 34% African American). Educational attainment (< 12 years or ≥12 years), occupation (non-managerial or not), and census block group household poverty rate (< 12%, 12 to 25%, > 25%) were examined separately and together in logistic models adjusting for covariates of age, gender, race, body mass index (BMI), smoking, knee injury and occupational activity score. Outcomes were presence of radiographic knee OA (rOA), symptomatic knee OA (sxOA), bilateral rOA and bilateral sxOA. When all three socioeconomic status (SES) variables were analyzed simultaneously, low educational attainment was significantly associated with rOA (odds ratio (OR) = 1.44, 95% confidence interval (CI) 1.20, 1.73), bilateral rOA (OR = 1.43, 95% CI 1.13, 1.81), and sxOA (OR = 1.66, 95% CI 1.34, 2.06), after adjusting for covariates. Independently, living in a community of high household poverty rate was associated with rOA (OR = 1.83, 95% CI 1.43, 2.36), bilateral rOA (OR = 1.56, 95% CI 1.12, 2.16), and sxOA (OR = 1.36, 95% CI 1.00, 1.83). Occupation had no significant independent association beyond educational attainment and community poverty. Both educational attainment and community SES were independently associated with knee OA after adjusting for primary risk factors for knee OA.

  18. Self-Organization of Coral Atolls and Their Response to Rising Sea Level and Ocean Acidification

    NASA Astrophysics Data System (ADS)

    Gutmann, E. D.; Anderson, R. S.; Tucker, G. E.

    2009-12-01

    Coral atolls are stunning both for their beauty and for their geomorphic organization. In addition, these islands are home to hundreds of thousands of people, and are threatened by both rising sea level and increasing ocean acidification. However, it has been suggested that the same geomorphic processes that formed these islands may continue to provide sediment at a rate sufficient to keep them above a rising sea level. A quantitative assessment of this hypothesis requires a numerical model that must first pass the test of being able to simulate the fundamental geomorphic and sedimentary structural features of a classic atoll. Here we present the first unified landscape process and carbonate growth model to capture the key components of an atoll. The model includes carbonate growth functions modified by light limitation, ocean chemistry, and surf zone energy. It also includes a physically based wave model, erosion by wave action, as well as dissolution and sediment transport functions that serve to modify the subaerial landscape. The model is initialized with a bare volcanic island subsiding at a rate of 0.1mm/yr. We then run the model through multiple glacial - interglacial sea level cycles. This model generates a landscape that matches the following atoll features: an annular island of loose sediment surrounded by a reef, gaps in this ring that are more abundant and larger on atolls with larger diameters, and a deep interior lagoon filled with a combination of autochthonous sediments as well as material transported inward from the outer reef. In addition, the island symmetry shifts in response to predominant wind-wave directions — large islands build on the windward side; islands are small or non-existent in the lee. While this model is not yet suitable for predictions of the fate of specific islands, it does suggest some general rules. If no substantial changes to the system occur, some of these islands may be able to keep pace with rising sea level; however

  19. 76 FR 17811 - Western Pacific Pelagic Fisheries; Prohibiting Purse Seine Fishing in the U.S. EEZ Around Guam...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-31

    ...., Wake, Baker, Howland, and Jarvis Islands, Johnston Atoll, Kingman Reef, and Palmyra Atoll). According... three new Marine National Monuments in the Marianas, Rose Atoll, and the Pacific Remote Islands Areas... exemption issued under Sec. 665.818. (1) Tutuila Island, Manua Islands, and Rose Atoll (AS-1). The...

  20. Holocene Sea-Level Record on Funafuti and Potential Impact of Global Warming on Central Pacific Atolls

    NASA Astrophysics Data System (ADS)

    Dickinson, William R.

    1999-03-01

    Geomorphic features inherited from the mid-Holocene glacio-hydro-isostatic sea-level highstand that affected the central Pacific region influence the susceptibility of atoll islets to potentially enhanced wave erosion associated with rise in sea level from global warming. Shoreline morphology on multiple islets of Funafuti atoll in central Tuvalu reflects a relative mid-Holocene sea-level highstand 2.2-2.4 m above modern sea level. Typical islets are composed of unconsolidated post-mid-Holocene sediment resting disconformably on cemented coral rubble formed beneath now-emergent mid-Holocene reef flats. Exposed remnants of the lithified islet foundations serve as resistant buttresses protecting the flanks of atoll islets from wave attack. Islets lacking cemented mid-Holocene deposits as part of their internal structure are migratory sand cays with unstable shorelines. Any future sea-level rise ≥0.75 m, bringing high tide above the elevation of mid-Holocene low tide, might trigger enhanced wave erosion of stable atoll islets by overtopping the indurated mid-Holocene reef platforms. As analogous threshold relations are inferred for other central Pacific atolls, the risk of future inundation of island nations cannot be evaluated solely in terms of expected sea-level rise with respect to gross islet elevations.

  1. POST-Eocene subsidence of the Marshall Islands recorded by drowned atolls on Harrie and Sylvania guyots

    NASA Astrophysics Data System (ADS)

    Schlanger, S. O.; Campbell, J. F.; Jackson, M. W.

    Geophysical and geological surveys of Harrie and Sylvania Guyots in the northern Marshall Islands show that both of these volcanic edifices are capped by drowned atolls of Early Eocene age. The volcanic eruptions that formed both of these guyots were apparently coeval with the eruptions that formed the volcanic edifice below Enewetak Atoll. These Eocene eruptions took place in an off-ridge setting in a region that had experienced a complex history of Cretaceous mid-plate volcanism. Present depths to the tops of these drowned Eocene atolls are 1520 m at Harrie and 1480 m at Sylvania which, taken together with the coeval subsidence of Enewetak atoll of ˜1300-1400 m and the post-Late Cretaceous subsidence of the Nauru Basin of ˜1600 m, show that this region has subsided rapidly, as a unit, atop a thermally rejuvenated lithosphere of Middle Jurassic age. The Eocene atolls on Harrie and Sylvania Guyots drowned during a rapid sea level rise ˜49 Ma that followed a period of relatively high sea levels in Early Eocene time.

  2. Individual Radiation Protection Monitoring in the Marshall Islands: Utrok Atoll (2003-2004)

    SciTech Connect

    Hamilton, T F; Kehl, S; Hickman, D; Brown, T; Marchetti, A A; Martinelli, R; Tibon, S; Chee, L

    2006-01-17

    The United States Department of Energy (U.S. DOE) has recently implemented a series of strategic initiatives to address long-term radiological surveillance needs at former U.S. nuclear test sites in the Marshall Islands. The plan is to engage local atoll communities in developing shared responsibilities for implementing radiation protection monitoring programs for resettled and resettling populations in the northern Marshall Islands. Using the pooled resources of the U.S. DOE and local atoll governments, individual radiological surveillance programs have been developed in whole body counting and plutonium urinalysis in order to accurately assess radiation doses resulting from the ingestion and uptake of fallout radionuclides contained in locally grown foods. Permanent whole body counting facilities have been established at three separate locations in the Marshall Islands (Figure 1). These facilities are operated and maintained by Marshallese technicians with scientists from the Lawrence Livermore National Laboratory (LLNL) providing on-going technical support services. Bioassay samples are collected under controlled conditions and analyzed for plutonium isotopes at the Center for Accelerator Mass Spectrometry at LLNL using state-of-the art measurement technologies. We also conduct an on-going environmental monitoring and characterization program at selected sites in the northern Marshall Islands. The aim of the environmental program is to determine the level and distribution of important fallout radionuclides in soil, water and local foods with a view towards providing more accurate and updated dose assessments, incorporating knowledge of the unique behaviors and exposure pathways of fallout radionuclides in coral atoll ecosystems. These scientific studies have also been essential in helping guide the development of remedial options used in support of island resettlement. Together, the individual and environmental radiological surveillance programs are helping meet

  3. Halogenated organic pollutants in marine biota from the Xuande Atoll, South China Sea: Levels, biomagnification and dietary exposure.

    PubMed

    Sun, Yu-Xin; Hu, Yong-Xia; Zhang, Zai-Wang; Xu, Xiang-Rong; Li, Heng-Xiang; Zuo, Lin-Zi; Zhong, Yi; Sun, Hong; Mai, Bi-Xian

    2017-03-11

    Six marine biota species were collected from the Xuande Atoll, South China Sea to investigate the bioaccumulation of dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane (DBDPE) and dechlorane plus (DP). Pike conger (Muraenesox talabonoides) had the highest concentrations of halogenated organic pollutants (HOPs) among the six marine biota species. DDTs were the predominant HOPs, followed by PCBs and PBDEs, with minor contributions of DBDPE and DP. Twenty-one percent of samples had ratios of (DDE+DDD)/ΣDDTs lower than 0.5, implying the presence of fresh DDT inputs in the environment of the Xuande Atoll. The biomagnification factor values for DDTs, PCBs, PBDEs and DP were higher than 1, suggesting biomagnification of these contaminants in the marine food chains. Consumption of seafood from the Xuande Atoll might not subject local residents in the coastal areas of South China to health risks as far as HOPs are concerned.

  4. Modeled atoll shoreline and run-up changes in response to sea-level rise and varying large wave conditions at Wake and Midway Atolls, Northwestern Hawaiian Islands

    NASA Astrophysics Data System (ADS)

    Shope, J. B.; Storlazzi, C. D.; Hoeke, R. K.

    2016-12-01

    Atoll islands are dynamic features that respond to seasonal alterations in wave conditions and sea level. With sea level and wave climates projected to change over the next century, it is unclear how shoreline wave runup and erosion patterns along these low elevation islands will respond, making it difficult for communities to prepare for the future. To investigate this, extreme boreal winter and summer wave conditions under a variety of future sea-level rise (SLR) scenarios were modeled at two atolls, Wake and Midway, using Delft3D. Nearshore wave conditions were used to find the potential longshore sediment flux, and wave-driven shoreline erosion was calculated as the divergence of the longshore drift; runup and the locations where runup exceed the berm elevation were also found. Of the aforementioned parameters, SLR is projected to be the dominant force driving future island morphological change and flooding. Increased sea level reduces depth-limited breaking by the atoll reef, allowing larger waves to reach the shoreline, increasing runup height and driving greater inland flooding along most coastlines. Previously protected shorelines, such as lagoon shorelines or shorelines with comparably wide reef flats, are projected see the greatest relative increases in runup. Increases in inland flooding extent were greatest along seaward shorelines due to increases in runup. Changes in incident wave directions had a smaller effect on runup, and the projected changes to incident wave heights had a negligible effect. SLR also drove the greatest changes to island shoreline morphology. Windward islands are projected to become thinner as seaward and lagoonal shorelines erode, accreting toward more leeward shorelines and shorelines with comparably wider reef flats. Similarly, leeward islands are anticipated to become thinner and longer, accreting towards their longitudinal ends. The shorelines of these islands will likely change dramatically over the next century as SLR and

  5. Effect of climate and environmental changes on plankton biodiversity and bigeochemical cycles of the Dongsha (Pratas) Atoll, South China Sea

    NASA Astrophysics Data System (ADS)

    Lo, Wen-tseng; Hsu, Pei-Kai; Hunag, Jia-Jang; Wang, Yu-Huai

    2013-04-01

    Dongsha (Pratas) Atoll, the so called "Pearl Crown of South China Sea", is a well-developed atoll with a total area of 80000 hectares. It possesses various ecosystems and has very high biodiversity, but it is very sensitive to climate change and physical processes. According to our investigation within the shallow semi-enclosed atoll in April, July, and October, 2011 (i.e., spring, summer, and autumn, respectively), we found that plankton assemblages and hydrographical conditions exhibited clear seasonal and spatial variations. Colder and higher salinity water was observed in April, while warmer water in July and lower salinity water in October, respectively. Nutrient concentration within the atoll was similar to that of the oligotrophic South China Sea waters and seemed to be in nitrogen-limit situation, while the distribution pattern of DOC and POC was mainly attributed to Chla and imported detritus matters. Carbon deposition flux also showed significant seasonal changes, but POC/PN value was near Redfield ratio, implying mostly due to biogenic factors; however it could still be classified as a typical coral ecosystem, since CaCO3 sinking flux generally was 30 times higher than that of organic matter. Plankton biodiversity was quite high in the atoll, and preformed apparent seasonal succession; in total, 82 phytoplankton species and 67 copepod species were recorded; furthermore, crab zoea (17.3% of the total zooplankton by number), fish eggs (12.5%), and shrimp larvae (4.2%), were relatively abundant in zooplankton community, revealed that atoll might be a good hatching ground. We deduced that the seasonal patterns of chemical and biological variables were mainly influenced by monsoons and precipitation, while small scales of temporal and spatial variations could be ascribed to internal wave and tide in this study area.

  6. Avian disease assessment in seabirds and non-native passerines birds at Midway Atoll NWR

    USGS Publications Warehouse

    LaPointe, Dennis A.; Atkinson, Carter T.; Klavitter, John L.

    2013-01-01

    Midway Atoll in the Northwestern Hawaiian Islands supports the largest breeding colony of Laysan albatross (Phoebastria immutabilis) in the world and is a proposed site for the translocation of endangered Northwestern Hawaiian Island passerine birds such as the Nihoa finch (Telespiza ultima), Nihoa millerbird (Acrocephalus familiaris kingi), or Laysan finch (Telespiza cantans). On the main Hawaiian Islands, introduced mosquito-borne avian malaria (Plasmodium relictum) and avian pox (Avipoxvirus) have contributed to the extinction and decline of native Hawaiian avifauna. The mosquito vector (Culex quinquefasciatus) is present on Sand Island, Midway Atoll, where epizootics of Avipoxvirus have been reported among nestling Laysan albatross, black-footed albatross (Phoebastria nigripes), and red-tailed tropicbirds (Phaethon rubricauda) since 1963. Two introduced passerines, the common canary (Serinus canaria) and the common myna (Acridotheres tristis), are also present on Sand Island and may serve as reservoirs of mosquito-borne pathogens. Assessing disease prevalence and transmission potential at Midway Atoll National Wildlife Refuge (NWR) is a critical first step to translocation of Nihoa endemic passerines. In May 2010 and April 2012 we surveyed Midway Atoll NWR for mosquitoes and evidence of mosquito-borne disease. Although we did not observe active pox infections on albatross nestlings in May 2010, active infections were prevalent on albatross nestlings in April 2012. Presumptive diagnosis of Avipoxvirus was confirmed by PCR amplification of the Avipoxvirus 4b core protein gene from lesions collected from 10 albatross nestlings. Products were sequenced and compared to 4b core protein sequences from 28 Avipoxvirus isolates from the Hawaiian Islands and other parts of the world. Sequences from all Midway isolates were identical and formed a clade with other Avipoxvirus isolates from seabirds that was distinct from other Avipoxvirus isolates from the Hawaiian Islands

  7. 240Pu/239Pu isotopic ratios and 239 + 240Pu total measurements in surface and deep waters around Mururoa and Fangataufa atolls compared with Rangiroa atoll (French Polynesia).

    PubMed

    Chiappini, R; Pointurier, F; Millies-Lacroix, J C; Lepetit, G; Hemet, P

    1999-09-30

    The average values of 240Pu/239Pu mass isotopic ratios of plutonium deposited in Mururoa and Fangataufa atoll sediments by French atmospheric nuclear tests range from 3.5 to 5%. In order to assess the near field and far field influence of those deposits in the open ocean, two water profiles were measured for 239 + 240Pu and 240Pu/239Pu using, for the first time, an Inductively Coupled Plasma Mass Spectrometer which was developed to achieve femtogram detection limits. One site was located at the limit of the French territorial waters, which is 22 km distant from Mururoa. The second site was located close to Rangiroa atoll, at a distance of approximately 1200-km from French nuclear test sites. The sample volumes were approximately 500 litres and plutonium was purified prior to mass spectrometry and alpha spectrometry measurements. In Rangiroa, the 239 + 240Pu profile is comparable with those already determined in world open oceans but the maximum detected activity, 9 mBq/m3 at 500-600 m is a lot lower than those measured in the northern hemisphere. 240Pu/239Pu ratios were measured between 500 and 1000 m and were not statistically different from the typical 0.18 +/- 0.01 ratio which characterises the global fallout. Consequently, any influence of plutonium from the tests in Mururoa and Fangataufa is not apparent at Rangiroa. The vertical distribution of 239 + 240Pu near Mururoa shows similar changes with depth but with a slight increase in concentration. 240Pu/239Pu mass ratios vary with depth, from 7 to 10% in the upper 500 m and in the deep waters (below 1000 m) to 15-16% between 600 and 1000 m. A contribution from plutonium deposited in the sediments at Mururoa and Fangataufa is observed at the limit of territorial waters, especially in surface and deep waters.

  8. Ground-water resources of the Laura area, Majuro Atoll, Marshall Islands

    USGS Publications Warehouse

    Hamlin, S.N.; Anthony, S.S.

    1987-01-01

    The water system that supplies the heavily populated Dalap-Uliga-Darrit (DUD) area of Majuro atoll, Marshall Island, relies almost entirely upon airstrip catchment of rain water. Droughts cause severe water supply problems and water rationing is required, even during periods of normal rainfall. The Laura area contains a substantial lens of fresh groundwater that could be developed for export to the DUD area 30 mi to the east. Study of the groundwater resource at Laura involved a survey of existing wells, installation of monitoring wells and test holes, compilation of continuous records of rainfall and water level fluctuations, and collection of water quality data. Test hole data permitted the definition of three geohydrologic units which correlate well with similar units in Bikini and Enewetak atolls. The units consist of two layers of unconsolidated reef and lagoon sediments resting on a dense, highly permeable limestone. The potable water zone, or freshwater nucleus, of the lens is contained mostly within the unconsolidated layers, which are much less permeable than the basal limestone. Recharge to the Laura freshwater lens is estimated to be 1.8 mil gal/day, based on an average annual rainfall of 140 in. Sustainable yield is estimated to be about 400,000 gal/day. Shallow skimming wells or infiltration galleries similar to those used on Kwajalein atoll would be appropriate to develop the freshwater lens. The impact of development on the lens can be determined by monitoring the salinity in developed water and in a network of monitor wells. (Author 's abstract)

  9. Coexistence of low coral cover and high fish biomass at Farquhar Atoll, Seychelles.

    PubMed

    Friedlander, Alan M; Obura, David; Aumeeruddy, Riaz; Ballesteros, Enric; Church, Julie; Cebrian, Emma; Sala, Enric

    2014-01-01

    We report a reef ecosystem where corals may have lost their role as major reef engineering species but fish biomass and assemblage structure is comparable to unfished reefs elsewhere around the world. This scenario is based on an extensive assessment of the coral reefs of Farquhar Atoll, the most southern of the Seychelles Islands. Coral cover and overall benthic community condition at Farquhar was poor, likely due to a combination of limited habitat, localized upwelling, past coral bleaching, and cyclones. Farquhar Atoll harbors a relatively intact reef fish assemblage with very large biomass (3.2 t ha(-1)) reflecting natural ecological processes that are not influenced by fishing or other local anthropogenic factors. The most striking feature of the reef fish assemblage is the dominance by large groupers, snappers, and jacks with large (>1 m) potato cod (Epinephelus tukula) and marbled grouper (E. polyphekadion), commonly observed at many locations. Napoleon wrasse (Cheilinus undulatus) and bumphead parrotfish (Bolbometopon muricatum) are listed as endangered and vulnerable, respectively, but were frequently encountered at Farquhar. The high abundance and large sizes of parrotfishes at Farquhar also appears to regulate macroalgal abundance and enhance the dominance of crustose corallines, which are a necessary condition for maintenance of healthy reef communities. Overall fish biomass and biomass of large predators at Farquhar are substantially higher than other areas within the Seychelles, and are some of the highest recorded in the Indian Ocean. Remote islands like Farquhar Atoll with low human populations and limited fishing pressure offer ideal opportunities for understanding whether reefs can be resilient from global threats if local threats are minimized.

  10. Coexistence of Low Coral Cover and High Fish Biomass at Farquhar Atoll, Seychelles

    PubMed Central

    Friedlander, Alan M.; Obura, David; Aumeeruddy, Riaz; Ballesteros, Enric; Church, Julie; Cebrian, Emma; Sala, Enric

    2014-01-01

    We report a reef ecosystem where corals may have lost their role as major reef engineering species but fish biomass and assemblage structure is comparable to unfished reefs elsewhere around the world. This scenario is based on an extensive assessment of the coral reefs of Farquhar Atoll, the most southern of the Seychelles Islands. Coral cover and overall benthic community condition at Farquhar was poor, likely due to a combination of limited habitat, localized upwelling, past coral bleaching, and cyclones. Farquhar Atoll harbors a relatively intact reef fish assemblage with very large biomass (3.2 t ha−1) reflecting natural ecological processes that are not influenced by fishing or other local anthropogenic factors. The most striking feature of the reef fish assemblage is the dominance by large groupers, snappers, and jacks with large (>1 m) potato cod (Epinephelus tukula) and marbled grouper (E. polyphekadion), commonly observed at many locations. Napoleon wrasse (Cheilinus undulatus) and bumphead parrotfish (Bolbometopon muricatum) are listed as endangered and vulnerable, respectively, but were frequently encountered at Farquhar. The high abundance and large sizes of parrotfishes at Farquhar also appears to regulate macroalgal abundance and enhance the dominance of crustose corallines, which are a necessary condition for maintenance of healthy reef communities. Overall fish biomass and biomass of large predators at Farquhar are substantially higher than other areas within the Seychelles, and are some of the highest recorded in the Indian Ocean. Remote islands like Farquhar Atoll with low human populations and limited fishing pressure offer ideal opportunities for understanding whether reefs can be resilient from global threats if local threats are minimized. PMID:24489903

  11. Evolution of reef and atoll margin carbonates, upper Eocene through lower Miocene, Enewetak, Marshall Islands

    SciTech Connect

    Saller, A.H.; Schlanger, S.O.

    1988-02-01

    Two wells drilled along the margin of Enewetak Atoll penetrated approximately 1000 m of upper Eocene, Oligocene, and lower Miocene carbonates. Strontium isotope stratigraphy indicates relatively continuous deposition of carbonate from 40 Ma to 20 Ma. Depositional environments show a gradual basinward progradation of facies with slope carbonates passing upward into fore-reef, reef, back-reef, and lagoonal carbonates. Slope strata contain wackestones and packstones with submarine-cemented lithoclasts, coral, coralline algae fragments, benthic rotaline forams, planktonic forams, and echinoderm fragments. Fore-reef strata are dominantly packstones and boundstones containing large pieces of coral, abundant benthic forams, coralline algae fragments, stromatoporoids( ), and minor planktonic forams. Reef and near-reef sediments include coralgal boundstones and grainstones with abundant benthic forams. Halimeda and miliolid forams are common in lagoonward parts of the back reef. Sponge borings, geopetal structures, and fractures are common in reef and fore-reef strata. Lagoonal strata are wackestones and packstones with common mollusks, coral, coralline algae, and benthic forams (rotaline and miliolid). Diagenesis has extensively altered strata near the atoll margin. Aragonite dissolution and calcite cements (radiaxial and cloudy prismatic) are abundant in fore-reef, reef, and some back-reef strata. Petrographic and geochemical data indicate aragonite dissolution and calcite cementation in seawater at burial depths of 100 to 300 m. Dolomite occurs in slope and deeply buried reefal carbonates. Most dolomitization occurred at burial depths of more than 1000 m in cool marine waters circulating through the atoll. lagoonal strata are not significantly altered by marine diagenesis and still contain abundant primary aragonite and magnesium calcite.

  12. Estimating transient freshwater lens dynamics for atoll islands of the Maldives

    NASA Astrophysics Data System (ADS)

    Bailey, Ryan T.; Khalil, Abedalrazq; Chatikavanij, Vansa

    2014-07-01

    The water resources of the atolls of the Republic of the Maldives are under continual threat from climatic and anthropogenic stresses, such as changing rainfall patterns, sea-level rise, and contamination from human activities and climatic events. Groundwater, a historically important resource of the island communities of the Maldives, is particularly affected due to the fragile nature of the freshwater lens on small atoll islands. In this study the dynamics of the freshwater lens are simulated during an extended (1998-2011) time period to determine the fluctuation of lens thickness of islands of the Maldives in response to annual and long-term changes in rainfall. Particularly, maximum and minimum lens thickness during the simulation period are assessed, as well as the occurrence of general trends, either decreasing or increasing, in lens thickness. Simulations are performed for a variety of island sizes, corresponding to the range of sizes of the islands of the Maldives, and for the various climatic regions of the Maldives. Results indicate that many of the atoll islands are expected to have a measurable freshwater lens during the majority of a long-term climatic period, although significant decreases in thickness can occur during the months of the dry season, with complete depletion occurring for small islands. Of particular note is the observation of a general decrease in lens thickness, approximately 2-4 cm/yr, over the 14-year period for the northern regions of the Maldives. If continued at current rates, these trends can have a significant impact on groundwater resources for the Maldives. Results imply that fresh groundwater, if properly protected from land surface-derived contamination and over-pumping and associated salinization, can be a valuable source of water for the Maldives, particularly for the larger islands. Overall, results provide water resource managers and government officials with valuable data for consideration in water security measures.

  13. Dynamics of Tidally Driven Nutrient Transport into a Semi-Enclosed Isolated Coral Reef Atoll

    NASA Astrophysics Data System (ADS)

    Green, R.; Lowe, R.; Jones, N. L.; Ivey, G. N.; Falter, J.; McCulloch, M. T.; Brinkman, R. M.

    2016-02-01

    The hydrodynamics within and surrounding coral reefs directly influence ecosystem productivity, community structure and diversity. Most studies on reef atolls have focused on shallow reef flats forced by surface waves, but fluxes of nutrients and heat driven by internal waves can be important within the deeper outer slopes and lagoons of many atolls. At present the number of studies into the effect of internal waves on reef environments are geographically limited, and principally for sites with relatively small tidal ranges. Scott Reef rises steeply from depths of 2500 m on the edge of Western Australia's continental slope. A combination of complex shelf topography, stable thermal stratification, and a large barotropic tide (>3m) contribute to the strong internal wave climate around this isolated atoll. The emphasis of this study is on the physical environment associated with the rich ecosystem in the large (300km2) and deep ( 50 m) semi-enclosed lagoon of South Scott. A multidisciplinary research cruise took place during April 2015. To investigate the dynamics of the internal waves influencing the lagoon, a mooring was deployed at a lagoon entrance with an array of current meters, temperature sensors and pressure sensors over a 15 day period. A simultaneous ship-based sampling programme of water column profiles, including water quality analysis, provided a comprehensive understanding of the how the physical environment contributes to maintaining this productive reef system. Results reveal that steep topography forces the internal waves to shoal into the north-east of the lagoon, transporting nutrient-rich deep water that results in a 3-fold increase in nitrate concentrations. Our field measurements indicate that cold water intrusions cause a baroclinic velocity response of 0.3 m s-1 and previous modelling studies reveal that the cold water can propagate up to 9 km into the lagoon at flood tide. The ecological implications for this replenishment of nutrients will

  14. Catastrophic impact of hurricanes on atoll outer reef slopes in the Tuamotu (French Polynesia)

    NASA Astrophysics Data System (ADS)

    Harmelin-Vivien, Mireille L.; Laboute, Pierre

    1986-10-01

    Underwater effects on coral reefs of the six hurricanes which ravaged French Polynesia between December 82 and April 83 were observed by SCUBA diving around high islands and atolls during September and October 1983. Special attention was paid to Tikehau atoll reef formations (Tuamotu archipelago) where quantitative studies on scleractinians, cryptofauna and fishes were conducted in 1982 immediatly prior to the hurricanes. On outer reef slopes coral destruction, varying from 50 to 100%, was a function of depth. Upper slope coral communities composed of small colonies well adapted to high energy level environments, suffered less than deeper formations. However, there is a narrow erosional trough in this zone at a depth of 6 m that was probably the result of storm-wave action (plunge point). Coral destruction was spectacular at depths greater than 12 m: 60 to 80% between 12 m and 30 m and 100% beyond 35 m, whereas earlier living coral coverage ranged from 60 to 75% in these zones. The outer slope was transformed into a scree zone covered with coarse sand and dead coral rubble. Dives on different sites around steep outer slopes (>45°) of the atolls and more gentle slopes (<25°) of some parts of the high islands permitted the formulation of an explanatory hypothesis: direct coral destruction by hurricane-induced waves occurred between the surface and 18 20 m; on low-angle slopes broken colonies were thrown up on reef flats and beaches; on steep slopes avalanches destroyed much of the living corals and left scree slopes of rubble and sand.

  15. Relationship between elemental distribution in soil and human impact in Majuro Atoll

    NASA Astrophysics Data System (ADS)

    Ito, L.; Takahashi, Y.; Yoneda, M.; Omori, T.; Yamazaki, K.; Yoshida, H.; Tamenori, Y.; Suga, H.; Yamaguchi, T.

    2015-12-01

    Majuro Atoll is one of islands of the Marshall Islands, located in the central Pacific Ocean. Reef-building corals and biological remains such as foraminifera have formed the islands under the influence of sea-level changes in the Holocene. Since the altitude of the general coral reef island tends to be very low, it is believed that the islands are vulnerable to natural disasters and climate change. However, people have lived in the Majuro Atoll in Marshall Islands for more than 2000 years. Reef islands in the same atoll are often considered to have same tendencies in the developing process; however, (i) there are possibilities that each geography produces different condition in habitat and (ii) human activities have changed the original nature in the island. In this study, we focus on the changes of physico-chemical conditions of soil depending on the depth according to time series variation in three islands in Majuro Atoll. Dating of each depth was conducted by radiocarbon (14C) measurement for foraminifera using accelerator mass spectrometry (AMS) and Bayesian age-depth Models. X-ray fluorescence (XRF) and ICP-MS analyses were employed to measure major and trace elements at different depth, respectively. Among them, phosphorus (P) is considered to play an important role in soil development; therefore X-ray absorption fine structure (XAFS) analysis was also conducted to examine the chemical form of P. Scanning electron microscope (SEM) was used to examine the elemental distribution in the soil particles, while X-ray computed tomography (CT) was used to calculate the rate of porosity of foraminifera at each depth. Concentrations of Fe, Mn, and P decrease with depth and vice versa for Mg. As a result of the μ-XAFS analysis, P in the soil exists as organic phosphorus and apatite. Phosphorous detected from the upper layer was found to distribute heterogeneously in the particles, which was observed as punctate pattern by the SEM observation. The ICP-MS results showed

  16. Uncharted waters: Bivalves of midway atoll and integrating mathematics into biology education

    NASA Astrophysics Data System (ADS)

    McCully, Kristin M.

    To protect and conserve the Earth's biodiversity and ecosystem services, it is important not only to understand and conserve species and ecosystems, but also to instill an understanding and appreciation for biodiversity and ecosystem services in the next generations of both scientists and citizens. Thus, this dissertation combines research into the ecology and identity of large bivalves at Midway Atoll in the Northwestern Hawaiian Islands (NWHI) with research on pedagogical strategies for integrating mathematics into undergraduate biology education. The NWHI is one of the few remaining large, mainly intact, predator-dominated coral reef ecosystems and one of the world's largest marine protected areas. Previous bivalve studies focused on the black-lipped pearl oyster, Pinctada margaritifera, which was heavily harvested in the late 1920s, has not recovered, and is now a candidate species for restoration. First, I combined remote sensing, geographic information systems, SCUBA, and mathematical modeling to quantify the abundance, spatial distributions, and filtration capacity of large epifaunal bivalves at Midway Atoll. These bivalves are most abundant on the forereef outside the atoll, but densities are much lower than reported on other reefs, and Midway's bivalves are unlikely to affect plankton abundance and productivity inside the lagoon. Second, I used molecular techniques and phylogenetic reconstructions to identify pearl oysters (Pinctada) from Midway Atoll as P. maculata , a species not previously reported in Hawaii. As a small morphologically cryptic species, P. maculata may be a native species that has not been collected previously, a native species that has been identified incorrectly as the morphologically similar P. radiata, or it may be a recent introduction or natural range extension from the western Pacific. Finally, I review science education literature integrating mathematics into undergraduate biology curricula, and then present and evaluate a

  17. Impacts of earthquake on atoll in Nansha Islands, South China Sea

    NASA Astrophysics Data System (ADS)

    Guo, Lei; Zhan, Wenhuan; Xiong, Lijia; Chen, Wujin; Yao, Yantao; Li, Jian

    2016-04-01

    Coral reef is a kind of rock soil masses. It is a special marine geotechnical medium, which are made up of the reef coral debris undergo very long geological age. Atoll is the predominant type of coral reefs in South China Sea. In recent years, there are more and more construction projects on the reef flat in Nansha Islands, South China Sea. Therefore, it is very important to estimate the stability of coral reefs, especially the atolls. According to the geological structure characters of atoll in Nansha Islands, a model of reef body is presented in this paper to study the influence of earthquake. Meanwhile, Geostudio, which is a popular geotechnical engineering simulation software, is used to stimulate the stress and deformation situation of reef body under different six kinds of earthquake intensity. The factor of safety can be calculated by the limit equilibrium method. And the possible scenario of earthquake-induced landslides and sliding scale can be defined through the Newmark sliding block method. The stress distribution and deformation behavior are studied. The main relations between atoll and earthquake are analyzed as follows: (1) the safety factor of reef slope exceeds 1.993 under self-gravity state; (2) It may cause slope's instability and bring slumping when the safety factor is less than one. The factor of safety decreases with increased earthquake intensity and it may fluctuate around a particular value when earthquake intensity continues to increase; (3) The smaller shallow landslide as new developed part of the reef is subject to collapse under earthquake action and the bigger slope of reef is more stable. The results show that it is feasible to evaluate the stability of coral reef by using geotechnical engineering simulation method, which can help to provide some information for construction on coral reefs in South China Sea. In the meantime,the authers wish to thank the National Natural Science Foundation of China (NO.41376063)and the National

  18. Palmyrolide A, an unusually stabilized neuroactive macrolide from Palmyra Atoll cyanobacteria.

    PubMed

    Pereira, Alban R; Cao, Zhengyu; Engene, Niclas; Soria-Mercado, Irma E; Murray, Thomas F; Gerwick, William H

    2010-10-15

    Palmyrolide A (1) is a new neuroactive macrolide isolated from a marine cyanobacterial assemblage composed of Leptolyngbya cf. and Oscillatoria spp. collected from Palmyra Atoll. It features a rare N-methyl enamide and an intriguing t-butyl branch; the latter renders the adjacent lactone ester bond resistant to hydrolysis. Consistent with its significant suppression of calcium influx in cerebrocortical neurons (IC(50) = 3.70 μM), palmyrolide A (1) showed a relatively potent sodium channel blocking activity in neuro-2a cells (IC(50) = 5.2 μM), without appreciable cytotoxicity.

  19. Palmyrolide A, an Unusually Stabilized Neuroactive Macrolide from Palmyra Atoll Cyanobacteria

    PubMed Central

    Pereira, Alban R.; Cao, Zhengyu; Engene, Niclas; Soria-Mercado, Irma E.; Murray, Thomas F.; Gerwick, William H.

    2010-01-01

    Palmyrolide A (1) is a new neuroactive macrolide isolated from a marine cyanobacterial assemblage composed of Leptolyngbya cf. and Oscillatoria spp. collected from Palmyra Atoll. It features a rare N-methyl enamide and an intriguing t-butyl branch; the latter renders the adjacent lactone ester bond resistant to hydrolysis. Consistent with its significant suppression of calcium influx in cerebrocortical neurons (IC50=3.70 µM), palmyrolide A (1) showed relatively potent sodium channel blocking activity in neuro-2a cells (IC50=5.2 µM), without appreciable cytotoxicity. PMID:20845912

  20. Radiation doses for Marshall Islands Atolls Affected by U.S. Nuclear Testing:All Exposure Pathways, Remedial Measures, and Environmental Loss of 137Cs

    SciTech Connect

    Robison, W L; Hamilton, T F

    2009-04-20

    The United States conducted 24 nuclear tests at Bikini Atoll with a total yield of 76.8 Megatons (MT). The Castle series produced about 60% of this total and included the Bravo test that was the primary source of contamination of Bikini Island and Rongelap and Utrok Atolls. One of three aerial drops missed the atoll and the second test of the Crossroads series, the Baker test, was an underwater detonation. Of the rest, 17 were on barges on water and 3 were on platforms on an island; they produced most of the contamination of islands at the atoll. There were 42 tests conducted at Enewetak Atoll with a total yield of 31.7 MT (Simon and Robison, 1997; UNSCEAR, 2000). Of these tests, 18 were on a barge over wateror reef, 7 were surface shots, 2 aerial drops, 2 under water detonations, and 13 tower shots on either land or reef. All produced some contamination of various atoll islands. Rongelap Atoll received radioactive fallout as a result of the Bravo test on March 1, 1954 that was part of the Castle series of tests. This deposition was the result of the Bravo test producing a yield of 15 MT, about a factor of three to four greater than the predicted yield that resulted in vaporization of more coral reef and island than expected and in the debris-cloud reaching a much higher altitude than anticipated. High-altitude winds were to the east at the time of detonation and carried the debris-cloud toward Rongelap Atoll. Utrok Atoll also received fallout from the Bravo test but at much lower air and ground-level concentrations than at Rongelap atoll. Other atolls received Bravo fallout at levels below that of Utrok [other common spellings of this island and atoll (Simon, et al., 2009)]. To avoid confusion in reading other literature, this atoll and island are spelled in a variety of ways (Utrik, Utirik, Uterik or Utrok). Dose assessments for Bikini Island at Bikini Atoll (Robison et al., 1997), Enjebi Island at Enewetak Atoll (Robison et al., 1987), Rongelap Island at

  1. 76 FR 10621 - Palmyra Atoll National Wildlife Refuge, U.S. Pacific Island Territory; Nonnative Rat Eradication...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-25

    ... exploitation of both marine and terrestrial natural resources by burgeoning human populations. Removing rats..., and large seabird populations are important Refuge resources. The Refuge is closed to commercial... all aspects of the Atoll's ecosystem, from breeding seabird populations to the native Pisonia...

  2. Hydrogeology and geochemistry of the freshwater lens on Roi Namur atoll, the Republic of the Marshall Islands

    NASA Astrophysics Data System (ADS)

    Swarzenski, P. W.

    2015-12-01

    More than 90% of the world's ~400 larger atoll islands are located in the Pacific and Indian Oceans and are inhabited by ~ 3/4 million people. As ground elevations of these atolls rarely exceed a few meters above mean sea level, atoll communities must rely precariously on finite resources, including fresh water and land. When demand for water exceeds precipitation rates, fresh groundwater may provide an additional, albeit also limited resource. The shape and size of this freshwater lens is controlled by precipitation, infiltration, discharge, and groundwater pumping, as well as hydrogeologic characteristics of the aquifer, and climate. Small atoll islands like Roi Namur on Kwajalein perhaps best illustrate the strong interdependence of the islet's depositional history and geochemical transformations that occur within the shallow aquifer and its host rock. This study utilized electrical resistivity tomography (ERT) to define the position of the freshwater lens above underlying seawater and to examine scales of freshwater /saltwater mixing. Time series Rn-222 measurements were used to evaluate groundwater discharge rates to the coastal waters, and a suite of groundwater geochemical tracers, including select nutrients, trace elements, and water isotopes, were used to develop a better understanding of how the fresh water lens will likely to respond to external perturbations, such as managed recharge, and the inevitability of future marine over wash events that will be become more frequent and severe under expected sea level rise.

  3. Potential impacts of historical disturbance on green turtle health in the unique & protected marine ecosystem of Palmyra Atoll (Central Pacific).

    PubMed

    McFadden, Katherine W; Gómez, Andrés; Sterling, Eleanor J; Naro-Maciel, Eugenia

    2014-12-15

    Palmyra Atoll, in the Central Pacific, is a unique marine ecosystem because of its remarkably intact food web and limited anthropogenic stressors. However during World War II the atoll was structurally reconfigured into a military installation and questions remain whether this may have impacted the health of the atoll's ecosystems and species. To address the issue we assessed green sea turtle (n=157) health and exposure to contaminants at this foraging ground from 2008 to 2012. Physical exams were performed and blood was sampled for testosterone analysis, plasma biochemistry analysis, hematology and heavy metal exposure. Hematological and plasma chemistries were consistent with concentrations reported for healthy green turtles. Heavy metal screenings revealed low concentrations of most metals, except for high concentrations of iron and aluminum. Body condition indices showed that <1% of turtles had poor body condition. In this study, we provide the first published blood values for a markedly healthy sea turtle population at a remote Central Pacific Atoll. Published by Elsevier Ltd.

  4. Geomorphological diversity of Dong-Sha Atoll based on spectrum and texture analysis in high resolution remote sensing imagery

    NASA Astrophysics Data System (ADS)

    Chen, Jianyu; Mao, Zhihua; He, Xianqiang

    2009-01-01

    Coral reefs are complex marine ecosystems that are constructed and maintained by biological communities that thrive in tropical oceans. The Dong-Sha Atoll is located at the northern continental margin of the South China Sea. It has being abused by destructive activity of human being and natural event during recent decades. Remote sensing offers a powerful tool for studying coral reef geomorphology and is the most cost-effective approach for large-scale reef survey. In this paper, the high-resolution Quickbird2 imageries which covered the full atoll are used to categorize the current distribution of coral reefs geomorphological structure therein with the auxiliary SPOT5 and ASTER imageries. Spectral and texture analysis are used to distinguish the geomorphological diversity during data processing. The Gray Level Co-occurrence Matrices is adopted for texture feature extraction and atoll geomorphology mapping in the high-resolution pan-color image of Quickbird2. Quickbird2 is considered as the most appropriate image source for coral reefs studies. In the Dong-Sha Atoll, various dynamical geomorphologic units are developed according to wave energy zones. There the reef frame types are classified to 3 different types according as its diversity at the image. The radial structure system is the most characteristic and from high resolution imagery we can distinguish the discrepancy between them.

  5. 3 CFR 8337 - Proclamation 8337 of January 6, 2009. Establishment of the Rose Atoll Marine National Monument

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... MonumentBy the President of the United States of America A Proclamation In the Pacific Ocean approximately... abundant marine life, deep sea coral forests, and several new fish and invertebrate species. Rose Atoll... with the balance of interests relating to traditional uses of the oceans recognizing freedom...

  6. Decomposition of buried human bodies and associated death scene materials on coral atolls in the tropical Pacific.

    PubMed

    Spennemann, D H; Franke, B

    1995-05-01

    The decomposition of bodies and the decay of associated cultural materials, including clothing, personal ornaments, caskets, and grave goods, was investigated based on a series of exhumations on a small sand island on Kwajalein Atoll, Marshall Islands. Decay data were documented for an interment period between 40 and 80 months.

  7. Evolution of reef and atoll margin carbonates, upper Eocene through lower Miocene, Enewetak, Marshall Islands

    SciTech Connect

    Saller, A.H.; Schlanger, S.O.

    1988-01-01

    Two wells drilled along the margin of Enewetak Atoll penetrated approximately 1,000 m of upper eocene, Oligocene, and lower Miocene carbonates. STrontium isotope stratigraphy indicates relatively continuous deposition of carbonate from 40 Ma to 20 Ma. Depositional environments show a gradual basinward progradation of facies with slope carbonates passing upward into fore-reef, reef, back-reef, and lagoonal carbonates. Slope strata contain wackestones and packstones with submarine-cemented lithoclasts, coral, coralline algae fragments, benthic rotaline forams, planktonic forams, and echinoderm fragments. Fore-reef strata are dominantly packstones and boundstones containing large pieces of coral, abundant benthic forams, coralline algae fragments, stromatoporoids(.), and minor planktonic forams. Reef and near-reef sediments include coralgal boundstones and grainstones with abundant benthic forams. Halimeda and miliolid forams are common in lagoonward parts of the back reef. Sponge borings, geopetal structures, and fractures are common in reef and fore-reef strata. Lagoonal strata are wackestones and packstones with common mollusks, coral, coralline algae, and benthic forams (rotaline and miliolid). Diagenesis has extensively altered strata near the atoll margin. Aragonite dissolution and calcite cements (radiaxial and cloudy prismatic are abundant in fore-reef, reef, and some back-reef strata). Petrographic and geochemical data indicate arogonite dissolution and calcite cementation in seawater at burial depths of 100 to 300 m. Dolomite occurs in slope and deeply buried reefal carbonates.

  8. Projections of extreme water level events for atolls in the western Tropical Pacific

    NASA Astrophysics Data System (ADS)

    Merrifield, M. A.; Becker, J. M.; Ford, M.; Yao, Y.

    2014-12-01

    Conditions that lead to extreme water levels and coastal flooding are examined for atolls in the Republic of the Marshall Islands based on a recent field study of wave transformations over fringing reefs, tide gauge observations, and wave model hindcasts. Wave-driven water level extremes pose the largest threat to atoll shorelines, with coastal levels scaling as approximately one-third of the incident breaking wave height. The wave-driven coastal water level is partitioned into a mean setup, low frequency oscillations associated with cross-reef quasi-standing modes, and wind waves that reach the shore after undergoing high dissipation due to breaking and bottom friction. All three components depend on the water level over the reef; however, the sum of the components is independent of water level due to cancelling effects. Wave hindcasts suggest that wave-driven water level extremes capable of coastal flooding are infrequent events that require a peak wave event to coincide with mid- to high-tide conditions. Interannual and decadal variations in sea level do not change the frequency of these events appreciably. Future sea-level rise scenarios significantly increase the flooding threat associated with wave events, with a nearly exponential increase in flooding days per year as sea level exceeds 0.3 to 1.0 m above current levels.

  9. Distribution, numbers, and habitat of Bristle-thighed Curlews (Numinous tahitiensis) on Rangiroa atoll

    USGS Publications Warehouse

    Gill, Robert E.; Redmond, Roland L.

    1992-01-01

    We assessed the numbers, distribution, and habitat of Bristle-tithed Curlews (Numinous tahitiensis) on Rangiroa Atoll, Tuamotu Archipelago, during a visit in April 1988. We estimated a total of 250-350 curlews on the atoll. These birds were seen only on the southern and western rims, where they were most common on (1) saltpans within clusters of small islets and (2) narrow channels between islets that were bordered by shrubs and herb mats. The distribution of curlews on Rangiroa appeared to be determined by the distribution of humans and their commensal animals and by the availability of habitats. Given the species' relatively low numbers, low reproductive rate, and prebasic moult which, for some adults, entails a flightless period, conservation and management efforts must begin on the non-breeding grounds. These efforts should focus on reducing or eliminating potential mortality factors such as subsistence harvest, introduced predators, and contaminants. Countries throughout the species' non-breeding range are encouraged to be active in these efforts.

  10. Post-Miocene diagenetic and eustatic history of Enewetak Atoll: Model and data comparison

    NASA Astrophysics Data System (ADS)

    Quinn, Terrence M.; Matthews, R. K.

    1990-10-01

    The post-Miocene diagenetic and eustatic history of Enewetak Atoll was investigated using a one-dimensional forward model. Comparison of model and data suggests that the post-Miocene history of Enewetak Atoll was dominated by multiple episodes of meteoric phreatic diagenesis attendant with high-frequency (104 to 105 yr) fluctuations in sea level and a subsidence rate of 39.0 m/m.y. Sensitivity testing indicates that subaerial erosion results in the preservation of additional subaerial unconformities because stratigraphic shortening permits a succeeding sea-level rise to flood the exposure surface and deposit sediment, whereas without subaerial erosion this sea-level rise would be recorded as a paleophreatic lens. Model results indicate that less than 10% of lapsed time is recorded by sediment deposition during periods of high-frequency changes in sea level. Incompleteness of the stratigraphic record suggests that magnetostratigraphy may give erroneous ages for shallow-marine carbonate sequences deposited during times of high-frequency changes in sea level and frequent magnetic polarity reversals.

  11. Productivity of Enewetak Atoll reef flats predicted from mass transfer relationships

    NASA Astrophysics Data System (ADS)

    Atkinson, M. J.

    1992-07-01

    The productivity of a coral reef flat at Enewetak Atoll is calculated by assuming phosphate (P) uptake is mass transfer limited, and then scaling P uptake to carbon (C) fixation. The approach is to treat the coral reef flat as a rough surface in fully-developed turbulent flow. Input parameters to the equations are water velocity, depth, roughness height of the reef, P concentration and the C:P ratio of autotrophs. A 9-day continuous record of water velocity and depth over the windward reef flats of Enewetak Atoll is used to compare an estimate of productivity from the model to the measured productivity. The calculated productivity is 542 ± 79mmol C m -2 day -1 and the measured productivity is 500 mmol C m -2 day -1. Although there are few experiments to verify empirical scaling of engineering equations to reef communities, these results indicate that neither alternative external supplies of P, nor biological mechanisms of recycling appear to be required to support the high areal productivity of the Enewetak reef flats. A high flow rate of tropical surface water across reef flats can account for the elevated productivity of these communities.

  12. Avian botulism: a case study in translocated endangered Laysan ducks (Anas laysanensis) on Midway Atoll

    USGS Publications Warehouse

    Work, Thierry M.; Klavitter, John L.; Reynolds, Michelle H.; Blehert, David S.

    2010-01-01

    Laysan Ducks are endemic to the Hawaiian archipelago and are one of the world’s most endangered waterfowl. For 150 yr, Laysan Ducks were restricted to an estimated 4 km2 of land on Laysan Island in the northwestern Hawaiian Islands. In 2004 and 2005, 42 Laysan Ducks were translocated to Midway Atoll, and the population increased to approximately 200 by 2007. In August 2008, mortality due to botulism type C was identified, and 181 adult, fledgling, and duckling carcasses were collected from August to October. Diseased birds were found on two islands within Midway Atoll at multiple wetlands; however, one wetland contributed most carcasses. The epidemic was discovered approximately 14–21 days after the mortality started and lasted for 50 additional days. The details of this epidemic highlight the disease risk to birds restricted to small island populations and the challenges associated with managing newly translocated endangered species. Frequent population monitoring for early disease detection and comprehensive wetland monitoring and management will be needed to manage avian botulism in endangered Laysan Ducks. Vaccination may also be beneficial to reduce mortality in this small, geographically closed population.

  13. X-ray Spectra of Accreting Neutron Stars in the Atoll and Z Subclasses

    NASA Astrophysics Data System (ADS)

    Remillard, Ronald A.; Lin, D.; Homan, J.

    2010-03-01

    We continue to find physical insights about atoll and Z sources by using a low-Comptonization spectral model for their soft states. In this decomposition, most of the radiation is thermal emission from two components: the accretion disk and the hotter boundary layer on the neutron star surface. Spectral analyses with RXTE then imply that atoll sources have nearly constant inner disk radius, consistent with a termination at the ISCO. This picture is largely confirmed in recent observations with Suzaku. On the other hand, Z sources show inner disk radii that increase with luminosity, suggesting the workings of the local Eddington limit. The flaring and normal branches can be understood as radius and advection instabilities, respectively, that disturb the Eddington-inflated disk. Patterns of spectral evolution are used to confirm the classification of GX13+1 as a Z source. We discuss implications for the origin of kHz QPOs. Finally, we compare the luminosity evolution of accreting black holes and neutron stars. This research was supported by NASA.

  14. [Physicochemical and sensory properties of flours ready to prepare an amaranth "atole"].

    PubMed

    Contreras López, Elizabeth; Jaimez Ordaz, Judith; Porras Martínez, Griselda; Juárez Santillán, Luis Felipe; Villanueva Rodríguez, Javier Añorve Morga y Socorro

    2010-06-01

    Atole is a Mexican pre-hispanic drink prepared traditionally with corn; however, cereals as wheat, rice and amaranth have also been used. The aim of this study was to determine the physicochemical and sensory properties of an amaranth flour to prepare a drink (atole) mentioned above, in order to determine its nutritive value. Proximate analysis of the amaranth, corn and rice drink flours was determined by means of official techniques of AOAC. Mineral content was carried out by atomic absorption spectrometry. Viscosity was measured in a reometer from 25 to 90 degrees C. The quantitative descriptive profile (QDA) of the amaranth drink was studied by a trained panel of 10 judges. Results showed that the amaranth drink flour presented the highest protein and fat content compared to corn and rice drink flours. Sodium and potassium were the most abundant minerals in all flours studied. Corn and rice drink flours showed a constant viscosity from 20 to 84 degrees C, to 85 degrees C an important increase in this parameter was observed. This increase was detected in the amaranth drink flour to 75 degrees C. Descriptors defined by trained judges for the QDA of the amaranth drink flours were: starch, almond/cherry, caramel, vanilla, strawberry, walnut and chocolate. The amaranth drink flour, compared to corn and rice drink flours, presented the best nutritional profile; it is important to emphasize its protein content.

  15. Decadal Variations in Western Pacific Warm Pool Dynamics as Evidenced by Porites Corals from Chuuk Atoll, Federated States of Micronesia

    NASA Astrophysics Data System (ADS)

    Massoll, J. L.; Wagner, A. J.; Anderson, D. M.; Lane, C.; Kim, J. K.; Lee, S. H.

    2014-12-01

    The Western Pacific Warm Pool (WPWP) encompasses some of the warmest sea surface temperatures (SSTs) of the world oceans. This region influences seasonal and decadal variability of the Intertropical Convergence Zone (ITCZ) and climate anomalies such as the El Niño-Southern Oscillation (ENSO). Long-term changes coupled with anomalous events like El Niño can greatly influence the position of the ITCZ and subsequently alter weather patterns on a global scale. WPWP dynamics may have contributed to the slowdown in global warming during the last decade. The processes that control these variations are complex, and gaining insight into these systems on decadal to centennial timescales is necessary to improve climate modeling and future predictions for drought or floods associated with global climate change. Chuuk Atoll (7°N, 152°E), located in the Federated States of Micronesia, is positioned within the WPWP at the northern extent of the mean boreal summer position of the ITCZ, making this location optimal for studying WPWP dynamics and ocean-atmosphere linkages. Two coral cores from the species Porites lobata were collected from the outer-atoll at Fannuk Island and the inner-atoll at Lobata Reef. Using stable isotope (δ18O and δ13C) composition and Sr/Ca trace metal analysis, the sites were identified as distinct hydrologic environments. Low seasonal variability in δ18O and Sr/Ca values at the outer-atoll site indicates a hydrologically-open system that is strongly influenced by the WPWP. At the inner-atoll site, δ18O and Sr/Ca values reflect a small seasonal SST cycle. In this hydrologically-restricted basin, the δ18O record is likely responding to salinity variations influenced by local climatology, specifically anomalously high or low precipitation events associated with ENSO. The average δ18O between 2003-2011 was 0.5‰ lighter at the inner-atoll site. These values can be interpreted as warmer sea surface temperatures and/or lower sea surface salinities

  16. An assessment of potential health impacts on Utrok Atoll from exposure to cesium-137 (137Cs) and plutonium

    SciTech Connect

    Hamilton, T

    2007-07-24

    Residual fallout contamination from the nuclear test program in the Marshall Islands is a concern to Marshall Islanders because of the potential health risks associated with exposure to residual fallout contamination in the environment. Scientists from Lawrence Livermore National Laboratory (LLNL) have been monitoring the amount of fallout radiation delivered to Utrok Atoll residents over the past 4 years. This briefing document gives an outline of our findings from the whole body counting and plutonium bioassay monitoring programs. Additional information can be found on the Marshall Islands web site (http://eed.lnl.gov/mi/). Cesium-137 is an important radioactive isotope produced in nuclear detonations and can be taken up from coral soils into locally grown food crop products that form an important part of the Marshallese diet. The Marshall Islands whole body counting program has clearly demonstrated that the majority of Utrok Atoll residents acquire a very small but measurable quantity of cesium-137 in their bodies (Hamilton et al., 2006; Hamilton et. al., 2007a; 2007b;). During 2006, a typical resident of Utrok Atoll received about 3 mrem of radiation from internally deposited cesium-137 (Hamilton et al., 2007a). The population-average dose contribution from cesium-137 is around 2% of the total radiation dose that people normally experience from naturally occurring radiation sources in the Marshall Islands and is thousands of times lower than the level where radiation exposure is known to produce measurable health effects. The existing dose estimates from the whole body counting and plutonium bioassay programs are also well below radiological protection standards for protection of the public as prescribed by U.S. regulators and international agencies including the Marshall Islands Nuclear Claim Tribunal (NCT). Similarly, the level of internally deposited plutonium found in Utrok Atoll residents is well within the range normally expected for people living in the

  17. Individual Radiation Protection Monitoring in the Marshall Islands: Enewetak Atoll (2002-2004)

    SciTech Connect

    Hamilton, T F; Kehl, S; Hickman, D; Brown, T; Marchetti, A A; Martinelli, R; Johannes, K; Henry, D

    2006-01-17

    The United States Department of Energy (U.S. DOE) has recently implemented a series of strategic initiatives to address long-term radiological surveillance needs at former U.S. nuclear test sites in the Marshall Islands. The plan is to engage local atoll communities in developing shared responsibilities for implementing radiation protection monitoring programs for resettled and resettling populations in the northern Marshall Islands. Using the pooled resources of the U.S. DOE and local atoll governments, individual radiological surveillance programs have been developed in whole body counting and plutonium urinalysis in order to accurately assess radiation doses resulting from the ingestion and uptake of fallout radionuclides contained in locally grown foods. Permanent whole body counting facilities have been established at three separate locations in the Marshall Islands including Enewetak Island (Figure 1) (Bell et al., 2002). These facilities are operated and maintained by Marshallese technicians with scientists from the Lawrence Livermore National Laboratory (LLNL) providing on-going technical support services. Bioassay samples are collected under controlled conditions and analyzed for plutonium isotopes at the Center for Accelerator Mass Spectrometry at LLNL using state-of-the art measurement technologies. We also conduct an on-going environmental monitoring and characterization program at selected sites in the northern Marshall Islands. The aim of the environmental program is to determine the level and distribution of important fallout radionuclides in soil, water and local foods with a view towards providing more accurate and updated dose assessments, incorporating knowledge of the unique behaviors and exposure pathways of fallout radionuclides in coral atoll ecosystems. These scientific studies have also been essential in helping guide the development of remedial options used in support of island resettlement. Together, the individual and environmental

  18. Individual Radiation Protection Monitoring in the Marshall Islands: Rongelap Atoll (2002-2004)

    SciTech Connect

    Hamilton, T F; Kehl, S; Hickman, D; Brown, T; Marchetti, A A; Martinelli, R; Arelong, E; Langinbelik, S

    2006-01-17

    The United States Department of Energy (U.S. DOE) has recently implemented a series of strategic initiatives to address long-term radiological surveillance needs at former U.S. nuclear test sites in the Marshall Islands. The plan is to engage local atoll communities in developing shared responsibilities for implementing radiation protection monitoring programs for resettled and resettling populations in the northern Marshall Islands. Using the pooled resources of the U.S. DOE and local atoll governments, individual radiological surveillance programs have been developed in whole body counting and plutonium urinalysis in order to accurately assess radiation doses resulting from the ingestion and uptake of fallout radionuclides contained in locally grown foods. Permanent whole body counting facilities have been established at three separate locations in the Marshall Islands including Rongelap Atoll (Figure 1). These facilities are operated and maintained by Marshallese technicians with scientists from the Lawrence Livermore National Laboratory (LLNL) providing on-going technical support services. Bioassay samples are collected under controlled conditions and analyzed for plutonium isotopes at the Center for Accelerator Mass Spectrometry at LLNL using state-of-the art measurement technologies. We also conduct an on-going environmental monitoring and characterization program at selected sites in the northern Marshall Islands. The aim of the environmental program is to determine the level and distribution of important fallout radionuclides in soil, water and local foods with a view towards providing more accurate and updated dose assessments, incorporating knowledge of the unique behaviors and exposure pathways of fallout radionuclides in coral atoll ecosystems. These scientific studies have also been essential in helping guide the development of remedial options used in support of island resettlement. Together, the individual and environmental radiological surveillance

  19. Comparison of the efficacies of botulinum toxin A and Johnstone pressure splints against hip adductor spasticity among patients with cerebral palsy: a randomized trial.

    PubMed

    Hazneci, Bulent; Tan, Arif Kenan; Guncikan, Mustafa Nuri; Dincer, Kemal; Kalyon, Tunc Alp

    2006-07-01

    The goal was to compare the efficacies of botulinum toxin A (BTX) treatment and Johnstone pressure splint (JPS) treatment against hip adductor muscle spasticity among children with spastic diplegic cerebral palsy. For each patient in the BTX group, a total of 300 IU of BTX was injected into adductor and medial hamstring muscle groups. In the JPS group, long leg JPS were administered for 30 minutes 3 days per week. Bobath neurodevelopmental exercises were administered to both groups 3 days per week during the study period. All cases were assessed by using gross motor function measurements, passive hip abduction goniometric measurements, modified Ashworth Scale scores, and measurements of the distance between the knees as indicator variables. We found that there was statistically significant improvement in all indicators for both groups. BTX treatment was found to be superior to JPS treatment in terms of the indicator variables of our study.

  20. Between-Habitat Variation of Benthic Cover, Reef Fish Assemblage and Feeding Pressure on the Benthos at the Only Atoll in South Atlantic: Rocas Atoll, NE Brazil.

    PubMed

    Longo, G O; Morais, R A; Martins, C D L; Mendes, T C; Aued, A W; Cândido, D V; de Oliveira, J C; Nunes, L T; Fontoura, L; Sissini, M N; Teschima, M M; Silva, M B; Ramlov, F; Gouvea, L P; Ferreira, C E L; Segal, B; Horta, P A; Floeter, S R

    2015-01-01

    The Southwestern Atlantic harbors unique and relatively understudied reef systems, including the only atoll in South Atlantic: Rocas atoll. Located 230 km off the NE Brazilian coast, Rocas is formed by coralline red algae and vermetid mollusks, and is potentially one of the most "pristine" areas in Southwestern Atlantic. We provide the first comprehensive and integrative description of the fish and benthic communities inhabiting different shallow reef habitats of Rocas. We studied two contrasting tide pool habitats: open pools, which communicate with the open ocean even during low tides, thus more exposed to wave action; and closed pools, which remain isolated during low tide and are comparatively less exposed. Reef fish assemblages, benthic cover, algal turfs and fish feeding pressure on the benthos remarkably varied between open and closed pools. The planktivore Thalassoma noronhanum was the most abundant fish species in both habitats. In terms of biomass, the lemon shark Negaprion brevirostris and the omnivore Melichtys niger were dominant in open pools, while herbivorous fishes (mainly Acanthurus spp.) prevailed in closed pools. Overall benthic cover was dominated by algal turfs, composed of articulated calcareous algae in open pools and non-calcified algae in closed pools. Feeding pressure was dominated by acanthurids and was 10-fold lower in open pools than in closed pools. Besides different wave exposure conditions, such pattern could also be related to the presence of sharks in open pools, prompting herbivorous fish to feed more in closed pools. This might indirectly affect the structure of reef fish assemblages and benthic communities. The macroalgae Digenea simplex, which is uncommon in closed pools and abundant in the reef flat, was highly preferred in herbivory assays, indicating that herbivory by fishes might be shaping this distribution pattern. The variations in benthic and reef fish communities, and feeding pressure on the benthos between open and

  1. Between-Habitat Variation of Benthic Cover, Reef Fish Assemblage and Feeding Pressure on the Benthos at the Only Atoll in South Atlantic: Rocas Atoll, NE Brazil

    PubMed Central

    Longo, G. O.; Morais, R. A.; Martins, C. D. L.; Mendes, T. C.; Aued, A. W.; Cândido, D. V.; de Oliveira, J. C.; Nunes, L. T.; Fontoura, L.; Sissini, M. N.; Teschima, M. M.; Silva, M. B.; Ramlov, F.; Gouvea, L. P.; Ferreira, C. E. L.; Segal, B.; Horta, P. A.; Floeter, S. R.

    2015-01-01

    The Southwestern Atlantic harbors unique and relatively understudied reef systems, including the only atoll in South Atlantic: Rocas atoll. Located 230 km off the NE Brazilian coast, Rocas is formed by coralline red algae and vermetid mollusks, and is potentially one of the most “pristine” areas in Southwestern Atlantic. We provide the first comprehensive and integrative description of the fish and benthic communities inhabiting different shallow reef habitats of Rocas. We studied two contrasting tide pool habitats: open pools, which communicate with the open ocean even during low tides, thus more exposed to wave action; and closed pools, which remain isolated during low tide and are comparatively less exposed. Reef fish assemblages, benthic cover, algal turfs and fish feeding pressure on the benthos remarkably varied between open and closed pools. The planktivore Thalassoma noronhanum was the most abundant fish species in both habitats. In terms of biomass, the lemon shark Negaprion brevirostris and the omnivore Melichtys niger were dominant in open pools, while herbivorous fishes (mainly Acanthurus spp.) prevailed in closed pools. Overall benthic cover was dominated by algal turfs, composed of articulated calcareous algae in open pools and non-calcified algae in closed pools. Feeding pressure was dominated by acanthurids and was 10-fold lower in open pools than in closed pools. Besides different wave exposure conditions, such pattern could also be related to the presence of sharks in open pools, prompting herbivorous fish to feed more in closed pools. This might indirectly affect the structure of reef fish assemblages and benthic communities. The macroalgae Digenea simplex, which is uncommon in closed pools and abundant in the reef flat, was highly preferred in herbivory assays, indicating that herbivory by fishes might be shaping this distribution pattern. The variations in benthic and reef fish communities, and feeding pressure on the benthos between open

  2. Projected atoll shoreline and run-up changes in response to sea-level rise and varying large wave conditions at Wake and Midway Atolls, Northwestern Hawaiian Islands

    NASA Astrophysics Data System (ADS)

    Shope, James B.; Storlazzi, Curt D.; Hoeke, Ron K.

    2017-10-01

    Atoll islands are dynamic features that respond to seasonal alterations in wave conditions and sea level. It is unclear how shoreline wave run-up and erosion patterns along these low elevation islands will respond to projected sea-level rise (SLR) and changes in wave climate over the next century, hindering communities' preparation for the future. To elucidate how these processes may respond to climate change, extreme boreal winter and summer wave conditions under future sea-level rise (SLR) and wave climate scenarios were simulated at two atolls, Wake and Midway, using a shallow-water hydrodynamic model. Nearshore wave conditions were used to compute the potential longshore sediment flux along island shorelines via the CERC empirical formula and wave-driven erosion was calculated as the divergence of the longshore drift; run-up and the locations where the run-up exceed the berm elevation were also determined. SLR is projected to predominantly drive future island morphological change and flooding. Seaward shorelines (i.e., ocean fronted shorelines directly facing incident wave energy) were projected to experience greater erosion and flooding with SLR and in hypothetical scenarios where changes to deep water wave directions were altered, as informed by previous climate change forced Pacific wave modeling efforts. These changes caused nearshore waves to become more shore-normal, increasing wave attack along previously protected shorelines. With SLR, leeward shorelines (i.e., an ocean facing shoreline but sheltered from incident wave energy) became more accretive on windward islands and marginally more erosive along leeward islands. These shorelines became more accretionary and subject to more flooding with nearshore waves becoming more shore-normal. Lagoon shorelines demonstrated the greatest SLR-driven increase in erosion and run-up. They exhibited the greatest relative change with increasing wave heights where both erosion and run-up magnitudes increased. Wider

  3. Projected atoll shoreline and run-up changes in response to sea-level rise and varying large wave conditions at Wake and Midway Atolls, Northwestern Hawaiian Islands

    USGS Publications Warehouse

    Shope, James B.; Storlazzi, Curt; Hoeke, Ron

    2017-01-01

    Atoll islands are dynamic features that respond to seasonal alterations in wave conditions and sea level. It is unclear how shoreline wave run-up and erosion patterns along these low elevation islands will respond to projected sea-level rise (SLR) and changes in wave climate over the next century, hindering communities' preparation for the future. To elucidate how these processes may respond to climate change, extreme boreal winter and summer wave conditions under future sea-level rise (SLR) and wave climate scenarios were simulated at two atolls, Wake and Midway, using a shallow-water hydrodynamic model. Nearshore wave conditions were used to compute the potential longshore sediment flux along island shorelines via the CERC empirical formula and wave-driven erosion was calculated as the divergence of the longshore drift; run-up and the locations where the run-up exceed the berm elevation were also determined. SLR is projected to predominantly drive future island morphological change and flooding. Seaward shorelines (i.e., ocean fronted shorelines directly facing incident wave energy) were projected to experience greater erosion and flooding with SLR and in hypothetical scenarios where changes to deep water wave directions were altered, as informed by previous climate change forced Pacific wave modeling efforts. These changes caused nearshore waves to become more shore-normal, increasing wave attack along previously protected shorelines. With SLR, leeward shorelines (i.e., an ocean facing shoreline but sheltered from incident wave energy) became more accretive on windward islands and marginally more erosive along leeward islands. These shorelines became more accretionary and subject to more flooding with nearshore waves becoming more shore-normal. Lagoon shorelines demonstrated the greatest SLR-driven increase in erosion and run-up. They exhibited the greatest relative change with increasing wave heights where both erosion and run-up magnitudes increased. Wider

  4. Review of solutions for 3D hydrodynamic modeling applied to aquaculture in South Pacific atoll lagoons.

    PubMed

    Andréfouët, S; Ouillon, S; Brinkman, R; Falter, J; Douillet, P; Wolk, F; Smith, R; Garen, P; Martinez, E; Laurent, V; Lo, C; Remoissenet, G; Scourzic, B; Gilbert, A; Deleersnijder, E; Steinberg, C; Choukroun, S; Buestel, D

    2006-10-01

    A workshop organized in French Polynesia in November 2004 allowed reviewing the current methods to model the three-dimensional hydrodynamic circulation in semi-enclosed atoll lagoons for aquaculture applications. Mollusk (e.g. pearl oyster, clam) aquaculture is a major source of income for South Pacific countries such as French Polynesia or Cook Islands. This aquaculture now requires a better understanding of circulation patterns to improve the spatial use of the lagoons, especially to define the best area to set larvae collectors. The pelagic larval duration of the relevant species (<20 days) and the size of the semi-closed lagoons (few hundreds of km2) drive the specifications of the model in terms of the spatial and temporal scale. It is considered that, in contrast with fish, mollusk larvae movements are limited and that their cycle occurs completely in the lagoon, without an oceanic stage. Atolls where aquaculture is productive are generally well-bounded, or semi-closed, without significant large and deep openings to the ocean. Nevertheless part of the lagoon circulation is driven by oceanic water inputs through the rim, ocean swells, tides and winds. Therefore, boundary conditions of the lagoon system are defined by the spatial structure of a very shallow rim (exposition and number of hoas), the deep ocean swell climate, tides and wind regimes. To obtain a realistic 3D numerical model of lagoon circulation with adequate forcing, it is thus necessary to connect in an interdisciplinary way a variety of methods (models, remote sensing and in situ data collection) to accurately represent the different components of the lagoon system and its specific boundary conditions. We review here the current methods and tools used to address these different components for a hypothetical atoll of the Tuamotu Archipelago (French Polynesia), representative of the semi-closed lagoons of the South Pacific Ocean. We hope this paper will serve as a guide for similar studies

  5. The Lagoon at Caroline/Millennium Atoll, Republic of Kiribati: Natural History of a Nearly Pristine Ecosystem

    PubMed Central

    Barott, Katie L.; Caselle, Jennifer E.; Dinsdale, Elizabeth A.; Friedlander, Alan M.; Maragos, James E.; Obura, David; Rohwer, Forest L.; Sandin, Stuart A.; Smith, Jennifer E.; Zgliczynski, Brian

    2010-01-01

    A series of surveys were carried out to characterize the physical and biological parameters of the Millennium Atoll lagoon during a research expedition in April of 2009. Millennium is a remote coral atoll in the Central Pacific belonging to the Republic of Kiribati, and a member of the Southern Line Islands chain. The atoll is among the few remaining coral reef ecosystems that are relatively pristine. The lagoon is highly enclosed, and was characterized by reticulate patch and line reefs throughout the center of the lagoon as well as perimeter reefs around the rim of the atoll. The depth reached a maximum of 33.3 m in the central region of the lagoon, and averaged between 8.8 and 13.7 m in most of the pools. The deepest areas were found to harbor large platforms of Favia matthaii, which presumably provided a base upon which the dominant corals (Acropora spp.) grew to form the reticulate reef structure. The benthic algal communities consisted mainly of crustose coralline algae (CCA), microfilamentous turf algae and isolated patches of Halimeda spp. and Caulerpa spp. Fish species richness in the lagoon was half of that observed on the adjacent fore reef. The lagoon is likely an important nursery habitat for a number of important fisheries species including the blacktip reef shark and Napoleon wrasse, which are heavily exploited elsewhere around the world but were common in the lagoon at Millennium. The lagoon also supports an abundance of giant clams (Tridacna maxima). Millennium lagoon provides an excellent reference of a relatively undisturbed coral atoll. As with most coral reefs around the world, the lagoon communities of Millennium may be threatened by climate change and associated warming, acidification and sea level rise, as well as sporadic local resource exploitation which is difficult to monitor and enforce because of the atoll's remote location. While the remote nature of Millennium has allowed it to remain one of the few nearly pristine coral reef

  6. The lagoon at Caroline/Millennium atoll, Republic of Kiribati: natural history of a nearly pristine ecosystem.

    PubMed

    Barott, Katie L; Caselle, Jennifer E; Dinsdale, Elizabeth A; Friedlander, Alan M; Maragos, James E; Obura, David; Rohwer, Forest L; Sandin, Stuart A; Smith, Jennifer E; Zgliczynski, Brian

    2010-06-03

    A series of surveys were carried out to characterize the physical and biological parameters of the Millennium Atoll lagoon during a research expedition in April of 2009. Millennium is a remote coral atoll in the Central Pacific belonging to the Republic of Kiribati, and a member of the Southern Line Islands chain. The atoll is among the few remaining coral reef ecosystems that are relatively pristine. The lagoon is highly enclosed, and was characterized by reticulate patch and line reefs throughout the center of the lagoon as well as perimeter reefs around the rim of the atoll. The depth reached a maximum of 33.3 m in the central region of the lagoon, and averaged between 8.8 and 13.7 m in most of the pools. The deepest areas were found to harbor large platforms of Favia matthaii, which presumably provided a base upon which the dominant corals (Acropora spp.) grew to form the reticulate reef structure. The benthic algal communities consisted mainly of crustose coralline algae (CCA), microfilamentous turf algae and isolated patches of Halimeda spp. and Caulerpa spp. Fish species richness in the lagoon was half of that observed on the adjacent fore reef. The lagoon is likely an important nursery habitat for a number of important fisheries species including the blacktip reef shark and Napoleon wrasse, which are heavily exploited elsewhere around the world but were common in the lagoon at Millennium. The lagoon also supports an abundance of giant clams (Tridacna maxima). Millennium lagoon provides an excellent reference of a relatively undisturbed coral atoll. As with most coral reefs around the world, the lagoon communities of Millennium may be threatened by climate change and associated warming, acidification and sea level rise, as well as sporadic local resource exploitation which is difficult to monitor and enforce because of the atoll's remote location. While the remote nature of Millennium has allowed it to remain one of the few nearly pristine coral reef

  7. Lyngbyabellins K-N from Two Palmyra Atoll Collections of the Marine Cyanobacterium Moorea bouillonii

    PubMed Central

    Byrum, Tara; Valeriote, Frederick A.; Gerwick, William H.

    2014-01-01

    Five lipopeptides of the lyngbyabellin structure class, four cyclic (1-3, and 5) and one linear (4), were isolated from the extracts of two collections of filamentous marine cyanobacteria obtained from Palmyra Atoll in the Central Pacific Ocean. Their planar structures and absolute configurations were elucidated by combined spectroscopic and chromatographic analyses as well as chemical synthesis of fragments. In addition to structural features typical of the lyngbyabellins, such as two thiazole rings and a chlorinated 2-methyloctanoate residue, these new compounds possess several unique aspects. Of note, metabolites 2 and 3 possessed rare mono-chlorination on the 3-acyloxy-2-methyloctanoate residue while lyngbyabellin N (5) had an unusual N,N-dimethylvaline terminus. Lyngbyabellin N also possessed a leucine statine residue, and showed strong cytotoxic activity against HCT116 colon cancer cell line (IC50 = 40.9 ± 3.3 nM). PMID:24574859

  8. The natural history of Enewetak Atoll: Volume 1, The ecosystem: Environments, biotas, and processes

    SciTech Connect

    Devaney, D.M.; Reese, E.S.; Burch, B.L.; Helfrich, P.

    1987-01-01

    The two volumes of The Natural History of Enewetak Atoll summarize research done at the Mid-Pacific Research Laboratory from 1954 to 1984 under the auspices of the Department of Energy. The history of the laboratory and the reasons for its support by the United States Department of Energy are described in Chapter 1 of Volume 1. Volume 1 provides a synthesis of the research carried out under the subject headings of the respective chapters. Certain of the chapters, e.g., those on geology, subtidal and intertidal environments and ecology, and those on reef processes and trophic relationships, summarize a great diversity of research carried out by many scientists for many years. In contrast, the chapters on meteorology and oceanography summarize research carried out under one integrated program involving fewer scientists working over a shorter period. Individual chapters are processed separately for the data base.

  9. Future Wave Height Situation estimated by the Latest Climate Scenario around Funafuti Atoll, Tuvalu

    NASA Astrophysics Data System (ADS)

    Sato, D.; Yokoki, H.; Kuwahara, Y.; Yamano, H.; Kayanne, H.; Okajima, H.; Kawamiya, M.

    2012-12-01

    Sea-level rise due to the global warming is significant phenomenon to coastal region in the world. Especially the atoll islands, which are low-lying and narrow, have high vulnerability against the sea-level rise. Recently the improved future climate projection (MIROC-ESM) was provided by JAMSTEC, which adopted the latest climate scenarios based on the RCP (Representative Concentration Pathway) of the green house gasses. Wave field simulation including the latest sea-level rise pathway by MIROC-ESM was conducted to understand the change of significant wave heights in Funafuti Atoll, Tuvalu, which was an important factor to manage the coast protection. MIROC-ESM provides monthly sea surface height in the fine gridded world (1.5 degree near the equator). Wave field simulation was conducted using the climate scenario of RCP45 in which the radioactive forcing of the end of 21st century was stabilized to 4.5 W/m2. Sea-level rise ratio of every 10 years was calculated based on the historical data set from 1850 to 2005 and the estimated data set from 2006 to 2100. In that case, the sea-level increases by 10cm after 100 years. In this study, the numerical simulation of wave field at the rate of sea-level rise was carried out using the SWAN model. The wave and wind conditions around Funafuti atoll is characterized by two seasons that are the trade (Apr. - Nov.) and non-trade (Jan. - Mar., Dec.) wind season. Then, we set up the two seasonal boundary conditions for one year's simulation, which were calculated from ECMWF reanalysis data. Simulated results of significant wave heights are analyzed by the increase rate (%) calculated from the base results (Average for 2000 - 2005) and the results of 2100. Calculated increase rate of the significant wave height for both seasons was extremely high on the reef-flat. Maximum increase rates of the trade and non-trade wind season were 1817% and 686%, respectively. The southern part of the atoll has high increasing rate through the two

  10. Transport of radionuclides from the Mururoa and Fangataufa atolls through the marine environment.

    PubMed

    Mittelstaedt, E; Osvath, I; Povinec, P P; Togawa, O; Scott, E M

    1999-09-30

    A dispersion of radionuclides (3H, 90Sr, 137Cs, 239Pu) potentially released from the Mururoa and Fangataufa atolls through the South Pacific Ocean has been studied by means of computer models. The models used consisted of three differently structured compartmental models for the regional field and a hydrodynamic world ocean model for the far-field simulations. The outcome of regional modelling is predicted activity concentrations with time in different regions of French Polynesia (over up to 10,000 years for plutonium). The far-field model simulates large-scale dispersion in the South Pacific Ocean over periods of up to 50 years. The overall result suggests that there will not be radioactive contamination of any radiological interest at inhabited sites in French Polynesia or anywhere else in the ocean at present or in the future.

  11. Normal hematologic values and prevalence of anemia in children living on selected Pacific atolls.

    PubMed

    Dungy, C I; Morgan, B C; Heotis, P M; Branson, H E; Adams, W H

    1987-01-01

    The hematologic status of infants and children living on the small islands of the Pacific basin has been poorly documented. This report determines the normal ranges for hemoglobin (Hb) and mean corpuscular volume (MCV) for children residing on four of the small atolls of the Republic of the Marshall Islands in the archipelago of Micronesia. The difficulty in establishing normal hematologic values in pediatric populations is discussed and a methodology suggested that does not exclude any Hb value above the mean in determining the normal range for Hb. The study population was comprised of 563 Marshallese children representing approximately 3.4% of all children less than 16 years of age living in the Marshall Islands. The local prevalence of anemia and iron deficiency was also established.

  12. Influence of quaternary sea-level variations on a land bird endemic to Pacific atolls.

    PubMed

    Cibois, Alice; Thibault, Jean-Claude; Pasquet, Eric

    2010-11-22

    Little is known about the effect of quaternary climate variations on organisms that inhabited carbonate islands of the Pacific Ocean, although it has been suggested that one or several uplifted islands provided shelter for terrestrial birds when sea-level reached its highest. To test this hypothesis, we investigated the history of colonization of the Tuamotu reed-warbler (Acrocephalus atyphus) in southeastern Polynesia, and found high genetic structure between the populations of three elevated carbonate islands. Estimates of time since divergence support the hypothesis that these islands acted as refugia during the last interglacial maximum. These findings are particularly important for defining conservation priorities on atolls that endure the current trend of sea-level rise owing to global warming.

  13. Translocation of wild Laysan Teal Anas laysanensis from Laysan Island to Midway Atoll: Project update

    USGS Publications Warehouse

    Reynolds, M.H.; Breeden, J.H.; Klavitter, J.L.

    2007-01-01

    The Laysan Teal Anas laysanensis is endemic to the Hawaiian Islands, where it has been restricted to Laysan Island over the last 150 years. Individuals of this endangered species have recently been translocated to the two largest islands that comprise Midway Atoll National Wildlife Refuge, to reduce the risk of the Laysan Teal becoming extinct. Post-release monitoring with the aid of radio-telemetry was conducted to determine the success of the reintroduction attempt during October 2004-2007. The population was found to have increased after three breeding seasons, from forty-two founders sourced directly from Laysan, to a population of ??? 192 post-fledglings juveniles and adults. ?? Wildfowl & Wetlands Trust.

  14. Recent variability in the Southern Oscillation: Isotopic results from a Tarawa Atoll coral

    SciTech Connect

    Cole, J.E.; Fairbanks, R.G. ); Shen, G.T. )

    1993-06-18

    In the western tropical Pacific, the interannual migration of the Indonesian Low convective system causes changes in rainfall that dominate the regional signature of the El Nino-Southern Oscillation (ENSO) system. A 96-year oxygen isotope record from a Tarawa Atoll coral (1[degrees]N, 172[degrees]E) reflects regional convective activity through rainfall-induced salinity changes. This monthly resolution record spans twice the length of the local climatological record and provides a history of ENSO variability comparable in quality with those derived from instrumental climate data. Comparison of this coral record with a historical chronology of El Nino events indicates that climate anomalies in coastal South America are occasionally decoupled from Pacific-wide ENSO extremes. Spectral analysis suggests that the distribution of variance in this record has shifted among annual to interannual periods during the present century, concurrent with observed changes in the strength of the Southern Oscillation. 28 refs., 2 figs., 1 tab.

  15. Restriction of sponges to an atoll lagoon as a result of reduced environmental quality.

    PubMed

    Knapp, Ingrid S S; Williams, Gareth J; Carballo, José Luis; Cruz-Barraza, José Antonio; Gardner, Jonathan P A; Bell, James J

    2013-01-15

    The lagoon at Palmyra Atoll in the central Pacific was subject to major military modifications during WWII and now the dominant fauna on the lagoon's hard substrate are sponges, not corals. In this study, we quantified the physical and biological factors explaining the variation in sponge distribution patterns across 11 sites to determine the potential for the sponges in the lagoon at Palmyra to invade the surrounding reef systems. Significant differences in sponge assemblages were found among all but three sites. For all the models we examined the strongest environmental relationships were found for variables related to sedimentation/turbidity and food/habitat availability. Our findings suggest that the sponges in Palmyra's lagoon are likely to be restricted to this habitat type where they are associated with conditions resulting from the earlier heavy disturbance and are unlikely to spread to the outer reef environments unless there is a dramatic decline in environmental quality.

  16. Influence of quaternary sea-level variations on a land bird endemic to Pacific atolls

    PubMed Central

    Cibois, Alice; Thibault, Jean-Claude; Pasquet, Eric

    2010-01-01

    Little is known about the effect of quaternary climate variations on organisms that inhabited carbonate islands of the Pacific Ocean, although it has been suggested that one or several uplifted islands provided shelter for terrestrial birds when sea-level reached its highest. To test this hypothesis, we investigated the history of colonization of the Tuamotu reed-warbler (Acrocephalus atyphus) in southeastern Polynesia, and found high genetic structure between the populations of three elevated carbonate islands. Estimates of time since divergence support the hypothesis that these islands acted as refugia during the last interglacial maximum. These findings are particularly important for defining conservation priorities on atolls that endure the current trend of sea-level rise owing to global warming. PMID:20554555

  17. Redistribution of fallout radionuclides in Enewetak Atoll lagoon sediments by callianassid bioturbation.

    PubMed

    McMurtry, G M; Schneider, R C; Colin, P L; Buddemeier, R W; Suchanek, T H

    The lagoon sediments of Enewetak Atoll in the Marshall Islands contain a large selection of fallout radionuclides as a result of 43 nuclear weapon tests conducted there between 1948 and 1958. Studies of the burial of fallout radionuclides have been conducted on the islands and in several of the large craters, but studies of their vertical distribution have been limited to about the upper 20 cm of the lagoon sediments. We have found elevated fallout radionuclide concentrations buried more deeply in the lagoon sediments and evidence of burrowing into the sediment by several species of callianassid ghost shrimp (Crustacea: Thalassinidea) which has displaced highly radioactive sediment. The burrowing activities of callianassids, which are ubiquitous on the lagoon floor, facilitate radionuclide redistribution and complicate the fallout radionuclide inventory of the lagoon.

  18. Paint chip poisoning of Laysan albatross at Midway Atoll (Pacific Ocean)

    USGS Publications Warehouse

    Sileo, L.; Fefer, S.I.

    1987-01-01

    Epizootic mortality occurred in Laysan albatross (Diomedea immutabilis) fledgings at Midway Atoll in 1983. Heavy metal toxicity from ingestion of weathered paint chips was one of the causes. Sick albatrosses were unable to retract their wings, causing a 'droop-wing' appearance. Five normal and 12 droop-winged fledglings were captured, killed, and examined. Paint chips found in the proventriculus of the affected fledglings contained up to 144,000 ppm lead. Blood, liver, and kidney concentrations of lead in affected birds were higher than in normal fledglings, and acid-fast intranuclear inclusion bodies were present in the kidneys. Degenerative lesions were present in the myelin of some brachial nerves. Weathered paint samples collected from 12 buildings contained up to 247,250 ppm lead and 101 ppm mercury. Lead poisoning was diagnosed in 10 of the droop-winged albatrosses and was one of the causes of morbidity. Mercury toxicosis and plastic impaction were other possible causes.

  19. Seafloor geomorphology and geology of the Kingman Reef-Palmyra Atoll region, Central Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Eakins, Barry; Barth, Ginger; Scheirer, Dan; Mosher, Dave; Armstrong, Andy

    2017-04-01

    Kingman Reef and Palmyra Atoll are the exposed summits of two seamounts within the Line Islands Volcanic Chain in the Central Pacific Ocean. Both are U.S. Territories, and the Exclusive Economic Zone around the islands was partially surveyed in 1991 with GLORIA sidescan sonar and seismic reflection profiling. New multibeam swath sonar surveys were conducted in 2010, 2015, and 2016 around the islands, in support of U.S. Extended Continental Shelf investigations. Numerous transits through the region by research vessels have collected additional multibeam swath sonar data. We present new, detailed maps of bathymetry, sidescan sonar imagery, geology, and sediment isopachs of the seafloor surrounding the islands, and how these have informed our understanding of the islands' margins. The islands are the last subaerial remnants of a complex, horse-shoe-shaped volcanic platform spanning roughly 200 km in diameter. The elevated platform from which the seamounts arise comprises at least 10 individual volcanic centers that have heights exceeding 3000m above the nearby abyssal plains. Gravity modeling suggests that the elevated platform is compensated by thickened crust. Strong carbonate caps and voluminous sediment accumulations flanking the platform indicate that the volcanoes were once shallow-water or emergent systems. These systems produced vast quantities of carbonate sediment that were shed to a deep interior basin to the east of Palmyra Atoll, and to nearby abyssal plains. The identification of mass failures, sediment reworking and bedforms, and channel networks provide evidence for extensive sedimentary processes around these volcanic centers. Analysis of the seamounts atop the elevated platform and in the seamount province to the northwest shows that flat-topped seamounts ("guyots") are principally found at depths shallower than 1300 meters, while peaked seamounts are almost exclusively found at greater depths. This constrains the amount of regional subsidence that

  20. Proximity to encroaching coconut palm limits native forest water use and persistence on a Pacific atoll

    USGS Publications Warehouse

    Krauss, Ken W.; Duberstein, Jamie A.; Cormier, Nicole; Young, Hillary S.; Hathaway, Stacie A.

    2015-01-01

    Competition for fresh water between native and introduced plants is one important challenge facing native forests as rainfall variability increases. Competition can be especially acute for vegetation on Pacific atolls, which depend upon consistent rainfall to replenish shallow groundwater stores. Patterns of sap flow, water use, and diameter growth of Pisonia grandis trees were investigated on Sand Islet, Palmyra Atoll, Line Islands, during a period of low rainfall. Sap flow in the outer sapwood was reduced by 53% for P. grandis trees growing within coconut palm (Cocos nucifera) stands (n = 9) versus away from coconut palm (n = 9). This suggested that water uptake was being limited by coconut palm. Radial patterns of sap flow into the sapwood of P. grandis also differed between stands with and without coconut palm, such that individual tree water use for P. grandis ranged from 14 to 67 L day−1, averaging 47·8 L day−1 without coconut palm and 23·6 L day−1 with coconut palm. Diameter growth of P. grandis was measured from nine islets. In contrast to sap flow, competition with coconut palm increased diameter growth by 89%, equating to an individual tree basal area increment of 5·4 versus 10·3 mm2 day−1. Greater diameter growth countered by lower rates of water use by P. grandis trees growing in competition with coconut palm suggests that stem swell may be associated with water storage when positioned in the understory of coconut palm, and may facilitate survival when water becomes limiting until too much shading overwhelms P. grandis. 

  1. Human Impact on Atolls Leads to Coral Loss and Community Homogenisation: A Modeling Study

    PubMed Central

    Riegl, Bernhard M.; Sheppard, Charles R. C.; Purkis, Sam J.

    2012-01-01

    We explore impacts on pristine atolls subjected to anthropogenic near-field (human habitation) and far-field (climate and environmental change) pressure. Using literature data of human impacts on reefs, we parameterize forecast models to evaluate trajectories in coral cover under impact scenarios that primarily act via recruitment and increased mortality of larger corals. From surveys across the Chagos, we investigate the regeneration dynamics of coral populations distant from human habitation after natural disturbances. Using a size-based mathematical model based on a time-series of coral community and population data from 1999–2006, we provide hind- and forecast data for coral population dynamics within lagoons and on ocean-facing reefs verified against monitoring from 1979–2009. Environmental data (currents, temperatures) were used for calibration. The coral community was simplified into growth typologies: branching and encrusting, arboresent and massive corals. Community patterns observed in the field were influenced by bleaching-related mortality, most notably in 1998. Survival had been highest in deep lagoonal settings, which suggests a refuge. Recruitment levels were higher in lagoons than on ocean-facing reefs. When adding stress by direct human pressure, climate and environmental change as increased disturbance frequency and modified recruitment and mortality levels (due to eutrophication, overfishing, pollution, heat, acidification, etc), models suggest steep declines in coral populations and loss of community diversification among habitats. We found it likely that degradation of lagoonal coral populations would impact regeneration potential of all coral populations, also on ocean-facing reefs, thus decreasing reef resilience on the entire atoll. PMID:22679482

  2. Human impact on atolls leads to coral loss and community homogenisation: a modeling study.

    PubMed

    Riegl, Bernhard M; Sheppard, Charles R C; Purkis, Sam J

    2012-01-01

    We explore impacts on pristine atolls subjected to anthropogenic near-field (human habitation) and far-field (climate and environmental change) pressure. Using literature data of human impacts on reefs, we parameterize forecast models to evaluate trajectories in coral cover under impact scenarios that primarily act via recruitment and increased mortality of larger corals. From surveys across the Chagos, we investigate the regeneration dynamics of coral populations distant from human habitation after natural disturbances. Using a size-based mathematical model based on a time-series of coral community and population data from 1999-2006, we provide hind- and forecast data for coral population dynamics within lagoons and on ocean-facing reefs verified against monitoring from 1979-2009. Environmental data (currents, temperatures) were used for calibration. The coral community was simplified into growth typologies: branching and encrusting, arboresent and massive corals. Community patterns observed in the field were influenced by bleaching-related mortality, most notably in 1998. Survival had been highest in deep lagoonal settings, which suggests a refuge. Recruitment levels were higher in lagoons than on ocean-facing reefs. When adding stress by direct human pressure, climate and environmental change as increased disturbance frequency and modified recruitment and mortality levels (due to eutrophication, overfishing, pollution, heat, acidification, etc), models suggest steep declines in coral populations and loss of community diversification among habitats. We found it likely that degradation of lagoonal coral populations would impact regeneration potential of all coral populations, also on ocean-facing reefs, thus decreasing reef resilience on the entire atoll.

  3. Studies of Accreting Neutron Stars with RXTE Cycle 4 Observations: III: TOO Observations of Atoll Sources

    NASA Technical Reports Server (NTRS)

    Paciesas, William S.

    2002-01-01

    NASA Grant NAG 5-9244 provided funds for the research projects 'ASM-Triggered TOO Observations of Kilohertz Oscillations in Five Atoll Sources' and 'Further Measurements of the Kilohertz Oscillations in 4U 1705-44' approved under the Rossi X-ray Timing Explorer (RXTE) Guest Observer Program Cycle 4 and funded under the 1999 NASA Astrophysics Data Program. The principal investigator of the observing time proposals was Dr. E. C. Ford (U. of Amsterdam). The grant was funded for one year beginning 3/15/2000. The original ADP proposal was submitted by Prof. Jan van Paradijs, who passed away in 1999 before the funds were distributed. Prof. Wilham S. Padesas administered the grant during the period of performance. In spite of a wealth of observational data on the kHz QPO in low-mass X-ray binaries (LMXBs), the interpretation of this phenomenon is currently uncertain because the pairs of kHz QPO peaks and the oscillations seen in some Type I X-ray bursts are almost, but not quite, connected by a simple beat frequency relation. Further systematic studies of systems with known QPOs are required in order to better understand the phenomenon. The proposals were intended to contribute to a solution to this confusion by observing the sources as they vary over a wide range of X-ray flux. RXTE target-of-opportunity observations of six transient atoll sources, 4U 0614+09, KS 1732-260, Ser X-1, 4U 1702-42, 4U 1820-30 and 4U 1705-44 were to be performed at various flux levels based on ASM measurements.

  4. From Submarine Volcanoes to Modern Atolls: New Insights from the Mozambique Channel (SW Indian Ocean)

    NASA Astrophysics Data System (ADS)

    Jorry, S.; Courgeon, S.; Camoin, G.; BouDagher-Fadel, M.; Jouet, G.; Poli, E.

    2016-12-01

    Although the long-term evolution of isolated shallow-water carbonate platforms leading to guyot and atoll formation has been the subject of numerous studies during the last decades, their driving processes are still the subject of active debates. The Mozambique Channel (SW Indian Ocean) is characterized by several modern carbonate platforms, ranging from 11°S to 21°S in latitudes. These platforms are characterized by reef margins mostly developed on windward sides with internal parts blanketed by sand dunes and numerous reef pinnacles, or by Darwin-type atolls with enclosed lagoons. Dredge sampling, underwater observations and geophysical acquisitions carried out during recent oceanographic cruises (PTOLEMEE and PAMELA-MOZ1) along slopes and basins adjacent to modern platforms led to the discovery of flat-top seamounts corresponding to shallow-water carbonate platforms which grew on top of submarine volcanoes. Microfacies and datings (biostratigraphy analysis coupled with Strontium isotopic stratigraphy) indicate that those carbonate platforms, characterized by fauna assemblages dominated by corals, Halimeda and red algaes, and larger benthic foraminifera, developed in tropical settings from Early Miocene to Late Miocene/Early Pliocene times. Submarine volcanism, karstification and pedogenesis evidences on top of the drowned edifices demonstrate that tectonic deformation, rejuvenated volcanic activity and subaerial exposure occurred after and potentially during the Neogene platform aggradation. Growth of modern platforms on top of submerged carbonate terraces is explained by topographic irregularities inherited from volcanism, tectonic and/or subaerial exposure conditions which could have produced favorable substratum for carbonates which grew during the Plio-Quaternary, up to reach modern sea-level. This research is co-funded by TOTAL and IFREMER as part of the PAMELA (Passive Margin Exploration Laboratories) scientific project.

  5. Concentrations of radionuclides in fish collected from Bikini Atoll between 1977 and 1984

    SciTech Connect

    Noshkin, V.E.; Wong, K.M.; Eagle, R.J.; Jokela, T.A.; Brunk, J.A.

    1986-07-01

    This report summarizes all available data on the concentrations of radionuclides in fish from Bikini Atoll between 1977 and 1984. As found in other global studies, /sup 137/Cs is most highly accumulated in edible flesh of all species of fish, the lowest fractions are found in the bone or liver. The mean concentration of /sup 137/Cs in muscle of reef fish from the southern part of the atoll is comparable to the global fallout concentration measured in market samples of fish collected from Chicago, Illinois, in 1982. /sup 90/Sr is generally associated with non-edible parts of fish, such as bone or viscera. Twenty-five to fifty percent of the total body burden of /sup 60/Co is accumulated in the muscle tissue; the remainder is distributed among the liver, skin, and viscera. The mean concentration of /sup 60/Co in fish has been decreasing at a rate faster than radiological decay alone. Most striking is the range of /sup 207/Bi concentrations among different species of fish collected at the same time and place. Highest concentrations of /sup 207/Bi were consistently detected in the muscle (and other tissues) of goatfish and some of the pelagic lagoon fish. In other reef fish, such as mullet, surgeonfish, and parrotfish, /sup 207/Bi was usually below detection limits by gamma spectrometry. Over 70% of the whole-body activity of /sup 207/Bi in goatfish is associated with the muscle tissue, whereas less than 5% is found in the muscle of mullet and surgeonfish. Neither /sup 239 +240/Pu nor /sup 241/Am is significantly accumulated in the muscle tissue of any species of fish. Apparently, /sup 238/Pu is in a more readily available form for accumulation by fishes than /sup 239 +240/Pu. Based on a daily ingestion rate of 200 q of fish flesh, dose rates to individuals through the fish-food ingestion pathway are well below current Federal guidelines.

  6. An updated dose assessment for a U.S. Nuclear Test Site - Bikini Atoll

    SciTech Connect

    Robison, W.L.; Bogen, K.T.; Conrado, C.L.

    1995-10-01

    On March 1, 1954, a nuclear weapon test, code-named BRAVO, conducted at Bikini Atoll in the northern Marshall Islands contaminated the major residence island. There has been a continuing effort since 1977 to refine dose assessments for resettlement options at Bikini Atoll. Here we provide a radiological dose assessment for the main residence island, Bikini, using extensive radionuclide concentration data derived from analysis of food crops, ground water, cistern water, fish and other marine species, animals, air, and soil collected at Bikini Island as part of our continuing research and monitoring program that began in 1975. The unique composition of coral soil greatly alters the relative contribution of cesium-137 ({sup 137}Cs) and strontium-90 ({sup 90}Sr) to the total estimated dose relative to expectations based on North American and European soils. Without counter measures, cesium-137 produces 96% of the estimated dose for returning residents, mostly through uptake from the soil to terrestrial food crops but also from external gamma exposure. The doses are calculated assuming a resettlement date of 1999. The estimated maximum annual effective dose for current island conditions is 4.0 mSv when imported foods, which are now an established part of the diet, are available. The corresponding 30-, 50-, and 70-y integral effective doses are 9.1 cSv, 13 cSv, and 15 cSv, respectively. A corresponding uncertainty analysis showed that after about 5 y of residence, the 95% confidence limits on population-average dose would be {plus_minus}35% of its expected value. We have evaluated various countermeasures to reduce {sup 137}Cs in food crops. Treatment with potassium reduces the uptake of {sup 137}Cs into food crops, and therefore the ingestion dose, to about 5% of pretreatment levels and has essentially no negative environmental consequences.

  7. Quantifying movement patterns for shark conservation at remote coral atolls in the Indian Ocean

    NASA Astrophysics Data System (ADS)

    Field, I. C.; Meekan, M. G.; Speed, C. W.; White, W.; Bradshaw, C. J. A.

    2011-03-01

    Grey reef sharks ( Carcharhinus amblyrhynchos) are apex predators found on many Indo-Pacific coral reefs, but little is known about their movement patterns and habitat requirements. We used acoustic telemetry to determine movements and habitat use of these sharks at the isolated Rowley Shoals atolls, 250 km off the coast of north-western Australia. We equipped 12 male and 14 female sharks ranging from 0.79 to 1.69 m in total length with transmitters that were detected by an array of 11 strategically placed receivers on two atoll reefs. Over 26,000 detections were recorded over the 325 days of receiver deployment. No sharks were observed to move between reefs. Receivers on the outer slopes of reefs provided nearly all (99%) of the detections. We found no differences in general attendance parameters due to size, sex or reef, except for maximum period of detection where larger sharks were detected over a longer period than smaller sharks. Male and female sharks were often detected at separate receivers at the outer slope habitat of one reef, suggesting sexual segregation, but this pattern did not occur at the second reef where males and females were detected at similar frequencies. We identified two patterns of daily behaviour: (1) sharks were present at the reef both day and night or (2) sharks spent more time in attendance during day than at night. Fast Fourier transforms identified 24-h cycles of attendance at the reef and a secondary peak of attendance at 12 h for most sharks, although no individuals shared the same attendance patterns. Our study provides baseline data that can be used to optimise the minimum area and habitat requirements for conservation of these apex predators.

  8. Beach development on an uplifted coral atoll: Niue, south west Pacific

    NASA Astrophysics Data System (ADS)

    Marsters, Teuvirihei Helene; Kennedy, David M.

    2014-10-01

    Niue is an uplifted coral atoll in the south western Pacific characterised by erosional terraces on its coastal margin. Beaches are found around the island located in pockets at the rear of erosional shore platforms. The beaches in Niue are < 100 m long, < 25 m wide and generally less than 0.5 m thick. The beaches sit on top of an abrasion ramp that dips seaward at a similar angle to the beach. The morphology, stability and sedimentology of these beaches are investigated through laser surveying, aerial photo analysis and petrographic techniques. Surveying was undertaken in 2008 and 2010 with data compared to previous work conducted in the 1990s in order to assess the controls on sediment deposition on uplifted coral atolls. There is a high potential for sediment transport on the island. The beaches are entirely removed during tropical cyclone events and even under calm conditions sediment is mobile. The restriction of beaches to pockets along the rocky coast suggests that these areas temporally interrupt sediment transport allowing beaches to form. All the beaches are composed of a typical chlorozoan assemblage of carbonate grains dominated by coral (20-50%), coralline algae (18%) and foraminifera (up to 81%). These sediments are produced on the platforms in the immediate vicinity of the beaches with little longshore transport between embayments being evident. The close relationship between source and depositional zones, combined with the high transport potential across the platforms indicates that the beaches are highly vulnerable to any change in either energy conditions or sediment supply.

  9. Studies of Accreting Neutron Stars with RXTE Cycle 4 Observations: III: TOO Observations of Atoll Sources

    NASA Technical Reports Server (NTRS)

    Paciesas, William S.

    2002-01-01

    NASA Grant NAG 5-9244 provided funds for the research projects 'ASM-Triggered TOO Observations of Kilohertz Oscillations in Five Atoll Sources' and 'Further Measurements of the Kilohertz Oscillations in 4U 1705-44' approved under the Rossi X-ray Timing Explorer (RXTE) Guest Observer Program Cycle 4 and funded under the 1999 NASA Astrophysics Data Program. The principal investigator of the observing time proposals was Dr. E. C. Ford (U. of Amsterdam). The grant was funded for one year beginning 3/15/2000. The original ADP proposal was submitted by Prof. Jan van Paradijs, who passed away in 1999 before the funds were distributed. Prof. Wilham S. Padesas administered the grant during the period of performance. In spite of a wealth of observational data on the kHz QPO in low-mass X-ray binaries (LMXBs), the interpretation of this phenomenon is currently uncertain because the pairs of kHz QPO peaks and the oscillations seen in some Type I X-ray bursts are almost, but not quite, connected by a simple beat frequency relation. Further systematic studies of systems with known QPOs are required in order to better understand the phenomenon. The proposals were intended to contribute to a solution to this confusion by observing the sources as they vary over a wide range of X-ray flux. RXTE target-of-opportunity observations of six transient atoll sources, 4U 0614+09, KS 1732-260, Ser X-1, 4U 1702-42, 4U 1820-30 and 4U 1705-44 were to be performed at various flux levels based on ASM measurements.

  10. Pacific Enewetak Atoll Crater Exploration (PEACE) Program, Enewetak Atoll, Republic of the Marshall Islands. Part 4. Analysis of borehole gravity surveys and other geologic and bathymetric studies in vicinity of Oak and Koa craters

    SciTech Connect

    Henry, T.W.; Wardlaw, B.R.

    1987-01-01

    The Pacific Enewetak Atoll Crater Exploration (PEACE) Program was established to resolve a number of questions for the Department of Defense (DOD) about the geologic and material-properties parameters of two craters (KOA and OAK), formed by near-surface bursts of high-yield thermonuclear devices on the northern margin of Enewetak Atoll, Marshall Islands, in 1958. The multidisciplinary studies conducted by the USGS in collaboration with other organizations during 1984 through 1987 were part of a much larger research initiative by the DNA to better understand the dynamic properties of strategic-scale nuclear bursts and the relevance of the Pacific Proving Grounds (PPG) craters to issues of strategic basing and targeting of nuclear weapons. Major topics include: Borehole gravity; Palentologic evidence for mixing; Electron paramagnetic resonance studies; Bathymetric studies of OAK crater; Constraints on densification and piping for OAK; and Additional studies of geologic crater models.

  11. Stomach nematodes (Mastophorus muris) in rats (Rattus rattus) are associated with coconut (Cocos nucifera) habitat at Palmyra Atoll.

    PubMed

    Lafferty, Kevin D; Hathaway, Stacie A; Wegmann, Alex S; Shipley, Frank S; Backlin, Adam R; Helm, Joel; Fisher, Robert N

    2010-02-01

    Black rats ( Rattus rattus ) and their stomach nematodes (Mastophorus muris) were historically introduced to islets at Palmyra Atoll in the central Pacific Line Islands. To investigate patterns of parasitism, we trapped rats and quantified nematodes on 13 islets of various sizes and habitat types. Most rats were parasitized (59%) with an average of 12 worms per infected rat. Islet size did not greatly influence parasite population biology. Nematodes also did not appear to affect rat condition (weight to skull length). The only strong and consistent factor associated with the mean abundance of nematodes in rats was habitat (dominant cover and locally dominant plant species). Thus, nematodes were much more abundant in rats from sites dominated by coconut trees (Cocos nucifera). Coconut trees may also be an introduced species at Palmyra Atoll.

  12. Stomach nematodes (Mastophorus Muris) in rats (Rattus rattus) are associated with coconut (Cocos nucifera) Habitat at palmyra atoll

    USGS Publications Warehouse

    Lafferty, K.D.; Hathaway, S.A.; Wegmann, A.S.; Shipley, F.S.; Backlin, A.R.; Helm, J.; Fisher, R.N.

    2010-01-01

    Black rats (Rattus rattus) and their stomach nematodes (Mastophorus muris) were historically introduced to islets at Palmyra Atoll in the central Pacific Line Islands. To investigate patterns of parasitism, we trapped rats and quantified nematodes on 13 islets of various sizes and habitat types. Most rats were parasitized (59) with an average of 12 worms per infected rat. Islet size did not greatly influence parasite population biology. Nematodes also did not appear to affect rat condition (weight to skull length). The only strong and consistent factor associated with the mean abundance of nematodes in rats was habitat (dominant cover and locally dominant plant species). Thus, nematodes were much more abundant in rats from sites dominated by coconut trees (Cocos nucifera). Coconut trees may also be an introduced species at Palmyra Atoll. ?? American Society of Parasitologists 2010.

  13. A half-century of coastline change in Diego Garcia - The largest atoll island in the Chagos

    NASA Astrophysics Data System (ADS)

    Purkis, Sam J.; Gardiner, Robert; Johnston, Matthew W.; Sheppard, Charles R. C.

    2016-05-01

    Being low and flat, atoll islands are often used as case studies against which to gauge the likely impacts of future sea-level rise on coastline stability. Furnished with lengthy temporal datasets, Pacific atolls form the majority of studies with scant information published for sites in the Indian Ocean. To address this imbalance, this study considers Diego Garcia, an atoll island situated in the remote equatorial Indian Ocean, which has undergone pronounced natural and anthropogenic change in the last fifty years. To explore the former, time separated remote sensing images spanning the years 1963-2013 are assembled to provide insight into the natural dynamics of the shoreline of this island and ocean climate data are compiled to investigate possible controls. Disregarding the precinct of the atoll on which a military complex has been constructed, overall land area of Diego Garcia decreased by a net value of only 0.92% between 1963 and 2013. While net island area is relatively unchanged, 12% of the shoreline that is not in the military precinct displayed discernible accretion and 15% has receded, with the lagoon-facing coastline having undergone the most pronounced changes and at rates higher than recorded for the island's exterior. Broad trends in the morphological adjustment of the island exist. The north-eastern limb of the atoll has generally receded while the south-eastern limb has extended. The south of the island has also extended, the south-western region has eroded and the north-western part has generally also eroded with the exception of notable shoreline extension at Simpson Point. The most common mechanism by which the lagoon-ward coastline has aggraded is through the in-filling of cuspate embayments with sediment which is later stabilized by the expansion of terrestrial vegetation. This evolution is most active in the complex network of embayments in the south of the atoll lagoon. The ocean-facing coastline, by contrast, typically aggrades and erodes

  14. The atmospheric lead record preserved in lagoon sediments at a remote equatorial Pacific location: Palmyra Atoll, northern Line Islands.

    PubMed

    Collen, John D; Baker, Joel A; Dunbar, Robert B; Rieser, Uwe; Gardner, Jonathan P; Garton, David W; Christiansen, Kylie J

    2011-02-01

    Anthropogenic lead (Pb) inputs to the atmosphere increased greatly over the past century and now dominate Pb supply to the oceans. However, the Pb content of sediments across the equatorial Pacific region is relatively unknown, and data exist only for deep sea sites where Pb deposition lags surface water inputs by up to a century. Here we present ICP-MS analyses of Pb of a core from a lagoon at Palmyra Atoll, northern Line Islands, that spans approximately the past 160 years. The non-bioturbated sediments of the euxinic lagoon, coupled with rapid rates of deposition, provide a unique fine-scale record of atmospheric Pb supply at a remote Pacific location. These first observations of historic Pb sedimentation in an atoll lagoon reveal a 63-fold increase in Pb flux to sediments during the past century and correlate directly with the North American consumption of leaded gasoline that began in 1926.

  15. 137Cs Inter-Plant Concentration Ratios Provide a Predictive Tool for Coral Atolls with Distinct Benefits Over Transfer Factors

    SciTech Connect

    Robison, W L; Hamilton, T F; Bogen, K; Corado, C L; Kehl, S R

    2007-07-17

    Inter-plant concentration ratios (IPCR), [Bq g{sup -1} {sup 137}Cs in coral atoll tree food-crops/Bq g{sup -1} {sup 137}Cs in leaves of native plant species whose roots share a common soil volume], can replace transfer factors (TF) to predict {sup 137}Cs concentration in tree food-crops in a contaminated area with an aged source term. The IPCR strategy has significant benefits relative to TF strategy for such purposes in the atoll ecosystem. IPCR strategy applied to specific assessments takes advantage of the fact tree roots naturally integrate 137Cs over large volumes of soil. Root absorption of {sup 137}Cs replaces large-scale, expensive soil sampling schemes to reduce variability in {sup 137}Cs concentration due to inhomogeneous radionuclide distribution. IPCR [drinking-coconut meat (DCM)/Scaevola (SCA) and Tournefortia (TOU) leaves (native trees growing on all atoll islands)] are log normally distributed (LND) with geometric standard deviation (GSD) = 1.85. TF for DCM from Enewetak, Eneu, Rongelap and Bikini Atolls are LND with GSD's of 3.5, 3.0, 2.7, and 2.1, respectively. TF GSD for Rongelap copra coconut meat is 2.5. IPCR of Pandanus fruit to SCA and TOU leaves are LND with GSD = 1.7 while TF GSD is 2.1. Because IPCR variability is much lower than TF variability, relative sampling error of an IPCR field sample mean is up 6- to 10-fold lower than that of a TF sample mean if sample sizes are small (10 to 20). Other IPCR advantages are that plant leaf samples are collected and processed in far less time with much less effort and cost than soil samples.

  16. (137)Cs inter-plant concentration ratios provide a predictive tool for coral atolls with distinct benefits over transfer factors.

    PubMed

    Robison, William L; Hamilton, Terry F; Bogen, Kenneth T; Conrado, Cynthia L; Kehl, Steven R

    2008-01-01

    Inter-plant concentration ratios (IPCR) [Bqg(-1)(137)Cs in coral atoll tree food crops/Bqg(-1)(137)Cs in leaves of native plant species whose roots share a common soil volume] can replace transfer factors (TF) to predict (137)Cs concentration in tree food crops in a contaminated area with an aged source term. The IPCR strategy has significant benefits relative to TF strategy for such purposes in the atoll ecosystem. IPCR strategy applied to specific assessments takes advantage of the fact that tree roots naturally integrate (137)Cs over large volumes of soil. Root absorption of (137)Cs replaces large-scale, expensive soil sampling schemes to reduce variability in (137)Cs concentration due to inhomogeneous radionuclide distribution. IPCR [drinking-coconut meat (DCM)/Scaevola (SCA) and Tournefortia (TOU) leaves (native trees growing on all atoll islands)] are log-normally distributed (LND) with geometric standard deviation (GSD)=1.85. TF for DCM from Enewetak, Eneu, Rongelap and Bikini Atolls are LND with GSDs of 3.5, 3.0, 2.7, and 2.1, respectively. TF GSD for Rongelap copra coconut meat is 2.5. IPCR of Pandanus fruit to SCA and TOU leaves are LND with GSD=1.7 while TF GSD is 2.1. Because IPCR variability is much lower than TF variability, relative sampling error of an IPCR field sample mean is up 6- to 10-fold lower than that of a TF sample mean if sample sizes are small (10-20). Other IPCR advantages are that plant leaf samples are collected and processed in far less time with much less effort and cost than soil samples.

  17. Geochronology and subsurface stratigraphy of Pukapuka and Rakahanga atolls, Cook Islands: Late Quaternary reef growth and sea level history

    USGS Publications Warehouse

    Gray, S.C.; Hein, J.R.; Hausmann, R.; Radtke, U.

    1992-01-01

    Eustatic sea-level cycles superposed on thermal subsidence of an atoll produce layers of high sea-level reefs separated by erosional unconformities. Coral samples from these reefs from cores drilled to 50 m beneath the lagoons of Pukapuka and Rakahanga atolls, northern Cook Islands give electron spin resonance (ESR) and U-series ages ranging from the Holocene to 600,000 yr B.P. Subgroups of these ages and the stratigraphic position of their bounding unconformities define at least 5 periods of reef growth and high sea-level (0-9000 yr B.P., 125,000-180,000 yr B.P., 180,000-230,000 yr B.P., 300,000-460,000 yr B.P., 460,000-650,000 yr B.P.). Only two ages fall within error of the last interglacial high sea-level stand (???125,000-135,000 yr B.P.). This paucity of ages may result from extensive erosion of the last intergracial reef. In addition, post-depositional isotope exchange may have altered the time ages of three coral samples to apparent ages that fall within glacial stage 6. For the record to be preserved, vertical accretion during rising sea-level must compensate for surface lowering from erosion during sea-level lowstands and subsidence of the atoll; erosion rates (6-63 cm/1000 yr) can therefore be calculated from reef accretion rates (100-400 cm/1000 yr), subsidence rates (2-6 cm/1000 yr), and the duration of island submergence (8-15% of the last 600,000 yr). The stratigraphy of coral ages indicates island subsidence rates of 4.5 ?? 2.8 cm/1000 yr for both islands. A model of reef growth and erosion based on the stratigraphy of the Cook Islands atolls suggests average subsidence and erosion rates of between 3-6 and 15-20 cm/1000 yr, respectively. ?? 1992.

  18. Distribution, size frequency, and sex ratios of blacktip reef sharks Carcharhinus melanopterus at Palmyra Atoll: a predator-dominated ecosystem.

    PubMed

    Papastamatiou, Y P; Caselle, J E; Friedlander, A M; Lowe, C G

    2009-08-01

    Blacktip reef sharks Carcharhinus melanopterus were the most abundant predator in the lagoons at Palmyra Atoll. They were evenly distributed throughout the lagoons, although there was some evidence of sexual segregation. Males reach sexual maturity between 940-1,020 mm L(T). Bird remains were found in some C. melanopterus stomachs. C. melanopterus at Palmyra appear to be smaller than those at other locations.

  19. Dialyzability of minerals in corn masa gruel (atole) fortified with different iron compounds: effects of ascorbic acid, disodium EDTA, and phytic acid.

    PubMed

    De-Regil, Luz Maria; Casanueva, Esther; Killilea, David W; Viteri, Fernando E

    2007-06-01

    Lime-treated corn gruel (atole) is a common weaning food in iron-deficient populations, especially in Mexico and Central America, and is a potential vehicle for fortification with iron. The objective of this study was to screen promising iron compounds for use in the fortification of atole, using in vitro enzymatic digestion-dialysis techniques, while also considering their response to known iron absorption enhancers and inhibitors. Atole, unaltered or preincubated with phytase, was fortified with iron (10 mg/L) from ferrous sulfate, ferrous bisglycinate, or ferrous fumarate, or with ferric chloride, ferric ammonium citrate, or ferric sodium ethylenediaminetetraacetic acid (NaFeEDTA), and submitted to in vitro digestion. Dialysis of calcium, copper, iron, phosphorus, and zinc (analyzed by inductively coupled plasma atomic emission spectrometry) was measured when atole was fortified with iron compounds alone or together with ascorbic acid or disodium ethylenediaminetetraacetic acid (Na2EDTA). Iron dialyzability was higher with NaFeEDTA (p < .05) than with all other iron compounds, which did not differ among themselves in iron dialyzability. Addition of ascorbic acid had no significant effect on iron dialysis, whereas Na2EDTA enhanced iron dialyzability by 7 to 10 times in unaltered atole and 15 to 20 times in phytase-preincubated atole (p < .05). Addition of Na2EDTA always increased intrinsic zinc dialyzability, and most of the time this increase was significant. Phytase pretreatment generally increased mineral dialysis. Adding EDTA (either as NaFeEDTA or as Na2EDTA) to atole can increase the dialyzability of ferrous and ferric iron compounds and enhance the dialyzability of intrinsic zinc without any negative effects on calcium, phosphorus, or copper dialysis.

  20. Arthropods of Rose Atoll with special reference to ants and Pulvinaria Urbicola Scales (Hempitera Coccidae) on Pisonia Grandis trees

    USGS Publications Warehouse

    Banko, Paul C.; Peck, Robert W.; Pendleton, Frank; Schmaedick, Mark; Ernsberger, Kelsie

    2014-01-01

    Rose Atoll, at the eastern end of the Samoan Archipelago, is a small but important refuge for seabirds, shorebirds, and sea turtles. While the vertebrate community is relatively well-studied, the terrestrial arthropod fauna, and its role in ecosystem function, are poorly known. Arthropods may be influencing the decline of Pisonia grandis, an ecologically important tree that once dominated the 6.6 ha of land on Rose Atoll. Reasons for the decline are not fully understood but a facultative relationship between two invasive arthropods, the soft scale Pulvinaria urbicola and ants, likely has contributed to tree death. The primary objectives of this study were to systematically survey the terrestrial arthropod fauna and identify ant species that tend scales on Pisonia. Using an array of standard arthropod collecting techniques, at least 73 species from 20 orders were identified, including nine ant species. Of the ants collected, only Tetramorium bicarinatum and T. simillimum were observed tending scales on Pisonia. No known natural enemies of Pulvinaria scales were found, suggesting little predation on scale populations. Treatment of Pisonia with the systemic insecticide imidacloprid failed to eliminate Pulvinaria scales, although short-term suppression apparently occurred. The arthropod fauna of Rose Atoll is dominated by exotic species that likely have a significant impact on the structure and function of the island’s ecosystem.

  1. Phase Shift from a Coral to a Corallimorph-Dominated Reef Associated with a Shipwreck on Palmyra Atoll

    PubMed Central

    Work, Thierry M.; Aeby, Greta S.; Maragos, James E.

    2008-01-01

    Coral reefs can undergo relatively rapid changes in the dominant biota, a phenomenon referred to as phase shift. Various reasons have been proposed to explain this phenomenon including increased human disturbance, pollution, or changes in coral reef biota that serve a major ecological function such as depletion of grazers. However, pinpointing the actual factors potentially responsible can be problematic. Here we show a phase shift from coral to the corallimorpharian Rhodactis howesii associated with a long line vessel that wrecked in 1991 on an isolated atoll (Palmyra) in the central Pacific Ocean. We documented high densities of R. howesii near the ship that progressively decreased with distance from the ship whereas R. howesii were rare to absent in other parts of the atoll. We also confirmed high densities of R. howesii around several buoys recently installed on the atoll in 2001. This is the first time that a phase shift on a coral reef has been unambiguously associated with man-made structures. This association was made, in part, because of the remoteness of Palmyra and its recent history of minimal human habitation or impact. Phase shifts can have long-term negative ramification for coral reefs, and eradication of organisms responsible for phase shifts in marine ecosystems can be difficult, particularly if such organisms cover a large area. The extensive R. howesii invasion and subsequent loss of coral reef habitat at Palmyra also highlights the importance of rapid removal of shipwrecks on corals reefs to mitigate the potential of reef overgrowth by invasives. PMID:18714355

  2. Phase shift from a coral to a corallimorph-dominated reef associated with a shipwreck on Palmyra atoll.

    PubMed

    Work, Thierry M; Aeby, Greta S; Maragos, James E

    2008-08-20

    Coral reefs can undergo relatively rapid changes in the dominant biota, a phenomenon referred to as phase shift. Various reasons have been proposed to explain this phenomenon including increased human disturbance, pollution, or changes in coral reef biota that serve a major ecological function such as depletion of grazers. However, pinpointing the actual factors potentially responsible can be problematic. Here we show a phase shift from coral to the corallimorpharian Rhodactis howesii associated with a long line vessel that wrecked in 1991 on an isolated atoll (Palmyra) in the central Pacific Ocean. We documented high densities of R. howesii near the ship that progressively decreased with distance from the ship whereas R. howesii were rare to absent in other parts of the atoll. We also confirmed high densities of R. howesii around several buoys recently installed on the atoll in 2001. This is the first time that a phase shift on a coral reef has been unambiguously associated with man-made structures. This association was made, in part, because of the remoteness of Palmyra and its recent history of minimal human habitation or impact. Phase shifts can have long-term negative ramification for coral reefs, and eradication of organisms responsible for phase shifts in marine ecosystems can be difficult, particularly if such organisms cover a large area. The extensive R. howesii invasion and subsequent loss of coral reef habitat at Palmyra also highlights the importance of rapid removal of shipwrecks on corals reefs to mitigate the potential of reef overgrowth by invasives.

  3. Phase shift from a coral to a corallimorph-dominated reef associated with a shipwreck on Palmyra atoll

    USGS Publications Warehouse

    Work, T.M.; Aeby, G.S.; Maragos, J.E.

    2008-01-01

    Coral reefs can undergo relatively rapid changes in the dominant biota, a phenomenon referred to as phase shift. Various reasons have been proposed to explain this phenomenon including increased human disturbance, pollution, or changes in coral reef biota that serve a major ecological function such as depletion of grazers. However, pinpointing the actual factors potentially responsible can be problematic. Here we show a phase shift from coral to the corallimorpharian Rhodactis howesii associated with a long line vessel that wrecked in 1991 on an isolated atoll (Palmyra) in the central Pacific Ocean. We documented high densities of R. howesii near the ship that progressively decreased with distance from the ship whereas R. howesii were rare to absent in other parts of the atoll. We also confirmed high densities of R. howesii around several buoys recently installed on the atoll in 2001. This is the first time that a phase shift on a coral leef has been unambiguously associated with man-made structures. This association was made, in part, because of the remoteness of Palmyra and its recent history of minimal human habitation or impact. Phase shifts can have long-term negative ramification for coral reefs, and eradication of organisms responsible for phase shifts in marine ecosystems can be difficult, particularly if such organisms cover a large area. The extensive R. howesii invasion and subsequent loss of coral reef habitat at Palmyra also highlights the importance of rapid removal of shipwrecks on corals reefs to mitigate the potential of reef overgrowth by invasives.

  4. Concentrations, Source and Risk Assessment of Polycyclic Aromatic Hydrocarbons in Soils from Midway Atoll, North Pacific Ocean

    PubMed Central

    Yang, Yuyi; Woodward, Lee Ann; Li, Qing X.; Wang, Jun

    2014-01-01

    This study was designed to determine concentrations of polycyclic aromatic hydrocarbons (PAHs) in soil samples collected from Midway Atoll and evaluate their potential risks to human health. The total concentrations of 16 PAHs ranged from 3.55 to 3200 µg kg−1 with a mean concentration of 198 µg kg−1. Higher molecular weight PAHs (4–6 ring PAHs) dominated the PAH profiles, accounting for 83.3% of total PAH mass. PAH diagnostic ratio analysis indicated that primary sources of PAHs in Midway Atoll could be combustion. The benzo[a]pyrene equivalent concentration (BaPeq) in most of the study area (86.5%) was less than 40 µg kg−1 BaPeq and total incremental lifetime cancer risks of PAHs ranged from 1.00×10−10 to 9.20×10−6 with a median value of 1.24×10−7, indicating a minor carcinogenic risk of PAHs in Midway Atoll. PMID:24466100

  5. Digenean metacercariae of fishes from the lagoon flats of Palmyra Atoll, Eastern Indo-Pacific

    USGS Publications Warehouse

    Vidal-Martínez, V. M.; Aguirre-Macedo, M. L.; McLaughlin, J.P.; Hechinger, R.F.; Jaramillo, A.G.; Shaw, J.C.; James, A.K.; Kuris, A.M.; Lafferty, Kevin D.

    2012-01-01

    Although many studies on the taxonomy of digenean trematodes of marine fishes have been completed in the Eastern Indo-Pacific (EIP) marine ecoregion, only a few have considered metacercarial stages. Here, the results are presented of a taxonomic survey of the digenean metacercariae of fishes from Palmyra Atoll, a remote and relatively pristine US National Wildlife Refuge located 1680 km SSW of Hawaii. Up to 425 individual fish were collected, comprising 42 fish species, from the sand flats bordering the lagoon of the atoll. Quantitative parasitological examinations of each fish were performed. Morphological descriptions of the encountered digenean metacercariae are provided, together with their prevalence, mean intensities, host and tissue-use. Up to 33,964 individuals were recovered representing 19 digenean metacercaria species from eight families. The species composition of digeneans in lagoon fishes at Palmyra Atoll is a subset of what has previously been reported for the EIP. Further, the large diversity and abundance of metacercariae reported in this study highlight the utility of including this group in future ecological research in the EIP marine ecoregion.

  6. 76 FR 18775 - Pacific Remote Islands Marine National Monument; Monument Management Plan, Comprehensive...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-05

    ... ecosystems with a biomass of top predators that exceeds the Great Barrier Reef's. At the conclusion of a 3..., Howland Island, Jarvis Island, Johnston Atoll, Kingman Reef, Palmyra Atoll, and Wake Atoll. When the draft... the following methods: E-mail: Pacific_Reefs@fws.gov . Fax: (808) 792-9586. U.S. Mail: Susan White...

  7. Species of Haliotrema Johnston & Tiegs, 1922 (Monogenea: Dactylogyridae) from Zanclus cornutus (L.) (Teleostei: Zanclidae) and Acanthurus nigrofuscus (Forsskål) (Teleostei: Acanthuridae) in the South China Sea.

    PubMed

    Sun, Yuan; Gibson, David I; Yang, Tingbao

    2011-07-01

    Four species of Haliotrema Johnston & Tiegs, 1922, including three new taxa, are described from the gills of two species of coral reef fishes, Zanclus cornutus (Linnaeus) and Acanthurus nigrofuscus (Forsskål), off the Dongsha Islands in the South China Sea. Haliotrema dongshaense n. sp., from Z. cornutus, is differentiated from other existing congeneric species by its peculiar male copulatory organ, comprising a harp-shaped copulatory tube and a cup-shaped base, and two groups of short longitudinal muscles lying on either side of the vaginal vestibule. Haliotrema zigmoidocirrus n. sp. from Z. cornutus and H. nigrofusci n. sp. from A. nigrofuscus are differentiated from other congeneric species by their male copulatory organ, which has a cup-shaped base, bell-shaped middle and Z-shaped distal part, and the latter can be readily differentiated from the former by its distinctively wider haptor and longer connecting bars. Haliotrema sicklocirrus Wang, 2007, from Z. cornutus, is redescribed with additional details, including the sinistral position of the accessory piece of the male copulatory organ, the absence of eyespots and the morphology of the connecting bars.

  8. Limited educational attainment and radiographic and symptomatic knee osteoarthritis: a cross-sectional analysis using data from the Johnston County (North Carolina) Osteoarthritis Project.

    PubMed

    Callahan, Leigh F; Shreffler, Jack; Siaton, Bernadette C; Helmick, Charles G; Schoster, Britta; Schwartz, Todd A; Chen, Jiu-Chiuan; Renner, Jordan B; Jordan, Joanne M

    2010-01-01

    Applying a cross-sectional analysis to a sample of 2,627 African-American and Caucasian adults aged > or = 45 years from the Johnston County Osteoarthritis Project, we studied the association between educational attainment and prevalence of radiographic knee osteoarthritis and symptomatic knee osteoarthritis. Age- and race-adjusted associations between education and osteoarthritis outcomes were assessed by gender-stratified logistic regression models, with additional models adjusting for body mass index, knee injury, smoking, alcohol use, and occupational factors. In an analysis of all participants, low educational attainment (<12 years) was associated with higher prevalence of four knee osteoarthritis outcomes (unilateral and bilateral radiographic and symptomatic osteoarthritis). Women with low educational attainment had 50% higher odds of having radiographic knee osteoarthritis and 65% higher odds of symptomatic knee osteoarthritis compared with those with higher educational attainment (> or = 12 years), by using fully adjusted models. In the subset of postmenopausal women, these associations tended to be weaker but little affected by adjustment for hormone replacement therapy. Men with low educational attainment had 85% higher odds of having symptomatic knee osteoarthritis by using fully adjusted models, but the association with radiographic knee osteoarthritis was explained by age. After adjustment for known risk factors, educational attainment, as an indicator of socioeconomic status, is associated with symptomatic knee osteoarthritis in both men and women and with radiographic knee osteoarthritis in women.

  9. Entomological fauna from Reserva Biológica do Atol das Rocas, RN, Brazil: I. Morphospecies composition.

    PubMed

    Almeida; Marchon-Silva; Ribeiro; Serpa-Filho; Almeida; Costa

    2000-05-01

    Atol das Rocas, the unique atoll in the South-western Atlantic, is located 144 nautical miles (266 Km) northeast from the city of Natal, NE Brazil and 80 nautical miles from Arquipélago de Fernando de Noronha, with geographic co-ordinates 3 masculine51'S and 33 masculine49"W. It's of volcanic origin and coralline formation. The reef is ellipsoid, its largest axis (E-W) is approximately 3.7 km long, and the shortest (N-S) is 2.5 km. Inside the lagoon, there are two islands: the Ilha do Farol and Ilha do Cemitério, which comprehend 7.2 Km2 of emerged area. The Atol das Rocas lodges 143,000 birds, mainly by Sula dactilatra, S. leucogaster, Anous stolidus, A. minuta and Sterna fuscata. Due to their remote location, the islands remain largely undisturbed by the human activities. Aiming to a first characterization of the entomological diversity and the general trophic niches of atoll's entomofauna, three collects were made (1994, 1995 and 1996) utilizing several methods for a wide sample. One thousand six hundred and six insect specimens were collected belonging to eight orders: 1. Coleoptera - 333 individuals of Dermestidae (Dermestes cadaverinus); Tenebrionidae (Phaleria testacea and morphospecies) and Curculionidae (one morphospecies); 2. Dermaptera - 50 individuals of Carcinophoridae (Anisolabis maritima); 3. Diptera - 281 individuals of Ephydridae (Scatella sp. and Hecamede sp.) and Hippoboscidae (one morphospecies); 4. Hymenoptera - 45 individuals of Formicidae (Brachymyrmex sp.); 5. Lepidoptera - 111 individuals of Microlepidoptera (one morphospecies); 6. Mallophaga - 18 individuals in birds (two morphospecies); 7. Orthoptera - 237 individuals of Acrididae (Schistocerca cancellata), Tridactylidae (one morphospecies) and Blattidae (three morphospecies); 8. Thysanoptera -531 individuals (one morphospecies). Also were collected 112 individuals of Arachnida. The taxa of the Order Araneae were represented by the families: 1. Miturgidae (Cheiracanthium inclusum); 2

  10. Radiation doses for Marshall Islands Atolls affected by U.S. nuclear testing: all exposure pathways, remedial measures, and environmental loss of (137)Cs.

    PubMed

    Robison, William L; Hamilton, Terry F

    2010-01-01

    Radiation doses calculated for people resettling Bikini Island at Bikini Atoll, Enjebi Island at Enewetak Atoll, Rongelap Island at Rongelap Atoll, and Utrōk Island at Utrōk Atoll are presented. Residence is assumed to begin in 2010. In previous dose assessments it was shown that (137)Cs accounts for about 98% of the total dose for returning residents. About 85 to 90% (depending on the atoll) is via consumption of locally grown foods containing (137)Cs, and about 10 to 15% is due to external exposure from (137)Cs in the soil. These assessments were made using only the radiological half-life of (137)Cs (30.1 y). We have shown since that there is an environmental loss of (137)Cs from soil to groundwater that results in a more rapid loss of (137)Cs from the atoll ecosystem. The mean effective half-life of (137)Cs at the atolls is 8.5 y. Moreover, treatment of coconut trees with potassium (K) reduces (137)Cs concentration in drinking coconut meat at Bikini Atoll to about 5% of pretreatment concentrations. The magnitude of reduction is dependent on the concentration of (137)Cs in soil, and thereby in food crops, and is less for Enjebi and Rongelap Islands than for Bikini Island. Treatment of food crops and fruit trees with K and removal of the top 15 cm of soil around houses and community buildings prior to construction to reduce external exposure where people spend most of their time has been presented to the communities as a "Combined Option" remediation strategy. Doses presented here are calculated using the Combined Option, effective half-life of (137)Cs at the atolls, and a diet of both imported and local foods. The average natural background dose in the Marshall Islands, plus the anthropogenic nuclear test-related dose at Bikini, Enjebi, and Rongelap Islands, is less for each of the islands than the average background dose in the U.S. and Europe.

  11. Revisiting wild stocks of black lip oyster Pinctada margaritifera in the Tuamotu Archipelago: The case of Ahe and Takaroa atolls and implications for the cultured pearl industry

    NASA Astrophysics Data System (ADS)

    Andréfouët, Serge; Thomas, Yoann; Dumas, Franck; Lo, Cédrik

    2016-12-01

    Spat collecting of the black lip oyster (Pinctada margaritifera) is the foundation of cultured black pearl production, the second source of income for French Polynesia. To understand spat collecting temporal and spatial variations, larval supply and its origin need to be characterized. To achieve this, it is necessary to account for the stock of oysters, its distribution and population characteristics (size distribution, sex-ratio). While the farmed stock in concessions can be easily characterized, the wild stock is elusive. Here, we investigate the distribution and population structure of the wild stock of Ahe and Takaroa atolls using fine-scale bathymetry and in situ census data. Stocks were surprisingly low (∼666,000 and ∼1,030,000 oysters for Ahe and Takaroa respectively) considering these two atolls have both been very successful spat collecting atolls in the past. Furthermore, in Ahe atoll, wild populations are aging with a dominant but small female population. Comparison with the cultured stock population (∼14 millions oysters) and its dominant young male population suggests that to maximize larval supply and spat collecting on the long term, it would be useful to increase the number of females in selected sanctuaries. We discuss the implication of our findings for the long-term management of stocks and for spat collection in pearl farming atolls, and for on-going numerical modelling studies on larval dispersal.

  12. Paleoseismology, seismic cycle and tectonic coupling of the Lesser Antilles subduction zone : Insights from micro-atolls

    NASA Astrophysics Data System (ADS)

    Weil Accardo, Jennifer; Feuillet, Nathalie; Tapponnier, Paul; Deschamps, Pierre; Cabioch, Guy; Le Cornec, Florence; Jacques, Eric; Galetzka, John; Saurel, Jean-Marie

    2010-05-01

    The Lesser Antilles arc is a region of high seismic hazard, which results from the convergence of American and Caribbean plates at 2cm/yr. Several earthquakes of magnitude ≥ 7 have struck the islands in the past. The largest, latest ones occurred only 4 years apart in the mid-19th century, on January 11, 1839 and February 8, 1843, destroying the towns of Fort-de-France and Pointe-à-Pitre, respectively, and killing several thousand people. Today, an earthquake comparable to that of 1843 might cause tens thousands of casualties in Guadeloupe. In addition to devastating seismic shaking, such earthquakes may trigger large tsunamis. In the Lesser Antilles, the behavior and seismic history of the plate interface remain unknown. Important questions that must be answered are: What is the exact geometry and segmentation of the subduction zone? How large might mega-thrust earthquakes be? What are typical recurrence times for such earthquakes on each segment? Could a large earthquake recur in the next few decades? To better understand and constrain the seismic hazard related to mega-thrust in the Lesser Antilles, we tend to retrieve the history of strain accumulation and relief at the plate interface from alive or dead corals. Certain coral species form micro-atolls that grow just below the intertidal zone and thus "fossilize" with their upper surfaces a history of local relative sea level. The annual coral band (or ring) growth is limited upwards by the so-called Highest Level of Survival (HLS, connected to the elevation of the yearly lowest tide level). When the sea level rises or drops due to tectonic or climatic events, the micro-atoll growth is perturbed. By analyzing in detail the coral aragonite skeleton, and U/Th dating specific events, it is possible to retrieve the history of sea level change through at least parts of several centuries. We identified several sites with living micro-atolls in the islands we visited (Martinique, Guadeloupe, Antigua, Barbuda). In

  13. Past and present levels of some radionuclides in fish from Bikini and Enewetak Atolls.

    PubMed

    Noshkin, V E; Robison, W L; Wong, K M; Brunk, J L; Eagle, R J; Jones, H E

    1997-07-01

    Bikini and Enewetak were the sites in the Northern Marshall Islands that were used by the United States as testing grounds for nuclear devices between 1946 and 1958. The testing produced close-in fallout debris that was contaminated with different radionuclides and which entered the aquatic environment. The contaminated lagoon sediments became a reservoir and source term of manmade radionuclides for the resident marine organisms. This report contains a summary of all the available data on the concentrations of 137Cs, 60Co and 207Bi in flesh samples of reef and pelagic fish collected from Bikini and Enewetak Atolls between 1964 and 1995. The selection of these three radionuclides for discussion is based on the fact that these are the only radionuclides that have been routinely detected by gamma spectrometry in flesh samples from all fish for the last 20 y. Flesh from fish is an important source of food in the Marshallese diet. These radionuclides along with the transuranic radionuclides and 90Sr contribute most of the small radiological dose from ingesting marine foods. Some basic relationships among concentrations in different tissues and organs are discussed. The reef fish can be used as indicator species because their body burden is derived from feeding, over a lifetime, within a relatively small contaminated area of the lagoon. Therefore, the emphasis of this report is to use this extensive and unique concentration data base to describe the effective half lives and cycling for the radionuclides in the marine environments during the 31-y period between 1964 and 1995. The results from an analysis of the radionuclide concentrations in the flesh samples indicate the removal rates for the 3 radionuclides are significantly different. 137Cs is removed from the lagoons with an effective half life of 9-12 y. Little 60Co is mobilized to the water column so that it is depleted in both environments, primarily through radioactive decay. The properties of 207Bi are different

  14. ''A ground water resources study of a Pacific Ocean atoll - Tarawa, Gilbert Islands,'' by J. W. Lloyd, J. C. Miles, G. R. Chessmand, and S. F. Bugg

    SciTech Connect

    Wheatcraft, S.W.; Buddemeier, R.W.

    1981-10-01

    Several inherent problems in the methodology employed in the ground water resource study of Tarawa Atoll (Lloyd, et al., 1981) are described. Studies of Enewetak Atoll have provided data that require a significantly different conceptual model of the atoll hydrogeology system. Comparison of well, lagoon, and ocean tidal observations with a mathematical model that assumes horizontal tidal propagation indicates that the observed results are more consistent with a system that is controlled by vertical coupling between the unconsolidated surface aquifer and an underlying aquifer of more permeable limestone. This indicates that most fresh water recharged to the aquifer migrates downward and mixes with the sea water in a deeper aquifer providing easy exchange with the ocean. Lloyd, et al., do not take tidal mixing or vertical transport into account and it therefore seems likely that fresh water inventories are significantly overestimated. Failure to include these significant loss terms in the island water budget may also account for calculated heads above ground level. (JMT)

  15. Ages of subsurface stratigraphic intervals in the Quaternary of Enewetak Atoll, Marshall Islands

    USGS Publications Warehouse

    Szabo, B. J.; Tracey, J.I.; Goter, E.R.

    1985-01-01

    Drill cores of Enewetak Atoll, Marshall Islands, reveal six stratigraphic intervals, numbered in downward sequence, which represent vertical coral growth during Quaternary interglaciations. Radiocarbon dates indicate that the Holocene sea transgressed the emergent reef platform by about 8000 yr B.P. The reef grew rapidly upward (about 5 to 10 mm/yr) until about 6500 yr B.P. Afterward vertical growth slowed to about 0.5 mm/yr, then lateral development became dominant during the last several thousand years. The second interval is dated at 131,000 ?? 3000 yr B.P. by uranium series. This unit correlates with oxygen-isotope substage 5e and with terrace VIIa of Huon Peninsula, New Guinea, and of Main Reef-2 terrace at Atauro Island. The third interval is not dated because corals were recrystallized and it is tentatively correlated with either oxygen-isotope stages 7 or 9. The age of the fourth interval is estimated at 454,000 ?? 100,000 yr B.P. from measured 234U 238U activity ratios. This unit is correlated with either oxygen-isotope stage 9, 11, or 13. ?? 1985.

  16. Paleomagnetism of Midway Atoll lavas and northward movement of the Pacific plate

    USGS Publications Warehouse

    Gromme, S.; Vine, F.J.

    1972-01-01

    Two deep drill holes through the reef limestones of Midway Atoll penetrated 120 m and 19 m of basaltic lavas that were dated by the KAr method at 18 my. Inclinations of natural remanent magnetization have been measured in 173 specimens cut from 57 core samples from 13 of the lava flows. The mean paleomagnetic inclination is 27.6?? ?? 6.8??, corresponding to a paleolatitude of 14.7?? ?? 4.2??. The present latitude of Midway is 28??, suggesting a northward component of motion of the Pacific plate of approximately 13?? or 1400 km in the last 18 my. The paleolatitude of Midway is thus not significantly different from the present latitude (19??) of the active volcanic island of Hawaii. The paleomagnetic data from the Midway basalts thus support the hypothesis of Wilson and Morgan that volcanic heat sources are fixed with respect to the Earth's mantle below the asthenosphere and their apparent migration with time is due to plate motion. ?? 1972.

  17. Wave characteristics and hydrodynamics at a reef island on Dongsha Atoll in the South China Sea

    NASA Astrophysics Data System (ADS)

    Su, Shih-Feng; Chiang, Te-Yun; Lin, Yi-Hao; Chen, Jia-Lin

    2017-04-01

    An inhabited coral reef island, located at the Dongsha Atoll in the northern South China Sea, is frequently attacked by typhoon waves. Coastline has suffered severe erosion and coastal inundation during certain typhoon paths. Groins were therefore built surround the island to stabilize the shoreline. However, the engineering structures redistributed the characteristics of hydrodynamics, which resulted in the disappearance of seasonal sediment movements on the reef flat. Additionally, infragravity waves (20-200 sec) on reefs have be found to generate strong resonance during energetic wave events. To understand wave characteristics and nearshore circulations around the reef under typical waves and typhoon waves, a phase-averaged and a phase-resolving wave models validated with previous field experiments are used to simulate significant wave height, wave setup and reef circulations. The phase-resolving model is specially applied to investigate infragravity motions around the island. Model results will illustrate the spatial variations of infragravity-wave field and wave-induced nearshore circulation and can provide information for coastal management and protection.

  18. Whale shark economics: a valuation of wildlife tourism in South Ari Atoll, Maldives

    PubMed Central

    Collins, Neal; Hancock, James; Rees, Richard

    2014-01-01

    Whale sharks attract large numbers of tourists, divers and snorkelers each year to South Ari Atoll in the Republic of Maldives. Yet without information regarding the use and economic extent of the attraction, it is difficult to prioritize conservation or implement effective management plans. We used empirical recreational data and generalized mixed statistical models to conduct the first economic valuation (with direct spend as the primary proxy) of whale shark tourism in Maldives. We estimated that direct expenditures for whale shark focused tourism in the South Ari Marine Protected Area for 2012 and 2013 accounted for US$7.6 and $9.4 million respectively. These expenditures are based on an estimate of 72,000–78,000 tourists who are involved in whale shark excursions annually. That substantial amount of income to resort owners and operators, and tourism businesses in a relatively small area highlights the need to implement regulations and management that safeguard the sustainability of the industry through ensuring guest satisfaction and whale shark conservation. PMID:25165629

  19. Thirty-year recovery of mollusc communities after nuclear experimentations on Fangataufa atoll (Tuamotu, French Polynesia).

    PubMed

    Legendre, Pierre; Salvat, Bernard

    2015-07-07

    A 30-year study of temporal changes in gastropod community structure on the reefs of a Pacific Ocean atoll (Fangataufa, Tuamotu Archipelago) subjected to atmospheric nuclear tests during the 1960s offered the opportunity for an otherwise impossible field experiment that could help ecologists understand mollusc primary succession. Reef molluscs were partly or entirely wiped out by the heat of the nuclear tests and the reefs were recolonized by ocean larvae. On all reefs, community composition before the tests was very different from what it evolved to afterwards. A new method of analysis was developed to study the temporal variation in community composition before versus after the tests (temporal beta diversity). Analyses showed that community compositions diverged through time among the reefs. Only some species can survive the harsh conditions of supralittoral zones, so the same species recolonized them; environmental filtering controlled the development of the new communities. In the reef flat and edge zones, differences in community composition seem to be the result of neutral stochastic colonization by larvae coming from the open ocean. All reefs developed a community composition quite different from that before the nuclear tests. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  20. Sediment studies at Bikini Atoll part 2. inventories of transuranium elements in surface sediments

    SciTech Connect

    Noshkin, V.E.; Eagle, R.J.; Wong, K.M.; Robison, W.L.

    1997-10-01

    This is the second of three reports on Bikini sediment studies, which discusses the concentrations and inventories of {sup 241}Am and {sup 239+240}Pu in sediments from the lagoon. Surface sediment samples were collected from 87 locations over the entire lagoon at Bikini Atoll during 1979. The collections were made to map the distribution of long-lived radionuclides associated with the bottom material and to show what modifications occurred in the composition of the sediment as a result of the testing program. Present inventories for {sup 241}Am and {sup 239+240}Pu in the surface 2 cm of sediment are estimated to be 14 and 17 TBq, respectively. These values are estimated to represent only 14% of the total inventory in the sediment column. Sediment inventories of {sup 239+240}Pu and {sup 241}Am are changing only slowly with time through chemical- physical processes that continuously mobilize small amounts of the transuranics to the water column. The lowest concentrations and inventories are associated with deposits logoonward of the eastern reef.

  1. Cholesterol, coconuts, and diet on Polynesian atolls: a natural experiment: the Pukapuka and Tokelau island studies.

    PubMed

    Prior, I A; Davidson, F; Salmond, C E; Czochanska, Z

    1981-08-01

    Two populations of Polynesians living on atolls near the equator provide an opportunity to investigate the relative effects of saturated fat and dietary cholesterol in determining serum cholesterol levels. The habitual diets of the toll dwellers from both Pukapuka and Tokelau are high in saturated fat but low in dietary cholesterol and sucrose. Coconut is the chief source of energy for both groups. Tokelauans obtain a much higher percentage of energy from coconut than the Pukapukans, 63% compared with 34%, so their intake of saturated fat is higher. The serum cholesterol levels are 35 to 40 mg higher in Tokelauans than in Pukapukans. These major differences in serum cholesterol levels are considered to be due to the higher saturated fat intake of the Tokelauans. Analysis of a variety of food samples, and human fat biopsies show a high lauric (12:0) and myristic (14:0) content. Vascular disease is uncommon in both populations and there is no evidence of the high saturated fat intake having a harmful effect in these populations.

  2. Sediment studies at Bikini Atoll part 1. distribution of fine and coarse components in surface sediments

    SciTech Connect

    Noshkin, V. E.; Eagle, R.J.; Robison, W.L.

    1997-01-01

    In 1979, 21 years after the moratorium on nuclear testing in the Marshall Islands, surface sediment samples (to depths of 2 and 4 cm) were collected from 87 locations over the floor of Bikini lagoon. The main purpose for the collections was to map the distribution of long- lived man-made radionuclides associated with the bottom material. In addition the samples were processed to estimate the fraction of fine and coarse components to show what modifications occurred since the sediment composition was first described in samples collected before testing in 1946. In this report a comparison is made of the amount and distribution of fine material associated with the lagoon surface sediment before and after the testing of nuclear devices. Nuclear testing produced more finely divided material in-the surface sediment layer over large areas of the lagoon and especially in regions of the lagoon and reef adjacent to test sites. Five cratering events at Bikini Atoll generated sufficient material to account for the inventory of new fine material found over the bottom surface of the lagoon. Although the fraction of fine material in the bottom sediments was altered by the nuclear events, the combined processes of formation, transport and deposition were not sufficiently dynamic to alter the geographical features of the major sedimentary components over most of the lagoon floor.

  3. Thirty-year recovery of mollusc communities after nuclear experimentations on Fangataufa atoll (Tuamotu, French Polynesia)

    PubMed Central

    Legendre, Pierre; Salvat, Bernard

    2015-01-01

    A 30-year study of temporal changes in gastropod community structure on the reefs of a Pacific Ocean atoll (Fangataufa, Tuamotu Archipelago) subjected to atmospheric nuclear tests during the 1960s offered the opportunity for an otherwise impossible field experiment that could help ecologists understand mollusc primary succession. Reef molluscs were partly or entirely wiped out by the heat of the nuclear tests and the reefs were recolonized by ocean larvae. On all reefs, community composition before the tests was very different from what it evolved to afterwards. A new method of analysis was developed to study the temporal variation in community composition before versus after the tests (temporal beta diversity). Analyses showed that community compositions diverged through time among the reefs. Only some species can survive the harsh conditions of supralittoral zones, so the same species recolonized them; environmental filtering controlled the development of the new communities. In the reef flat and edge zones, differences in community composition seem to be the result of neutral stochastic colonization by larvae coming from the open ocean. All reefs developed a community composition quite different from that before the nuclear tests. PMID:26063849

  4. Gross and microscopic morphology of lesions in Cnidaria from Palmyra Atoll, Central Pacific

    USGS Publications Warehouse

    Williams, Gareth J.; Work, Thierry M.; Aeby, Greta S.; Knapp, Ingrid S.; Davy, Simon K.

    2011-01-01

    We conducted gross and microscopic characterizations of lesions in Cnidaria from Palmyra Atoll, Central Pacific. We found growth anomalies (GA) to be the most commonly encountered lesion. Cases of discoloration and tissue loss were rare. GAs had a focal or multi-focal distribution and were predominantly nodular, exophytic, and umbonate. In scleractinians, the majority of GAs manifested as hyperplasia of the basal body wall (52% of cases), with an associated absence or reduction of polyp structure (mesenteries and filaments, actinopharynx and tentacles), and depletion of zooxanthellae in the gastrodermis of the upper body wall. In the soft corals Sinularia sp. and Lobophytum sp., GAs exclusively manifested as prominent hyperplasia of the coenenchyme with an increased density of solenia. In contrast to scleractinians, soft coral GAs displayed an inflammatory and necrotizing component with marked edema of the mesoglea, accompanied by infiltrates of variably-sized granular amoebocytes. Fungi, algae, sponges, and Crustacea were present in some scleractinian GAs, but absent in soft coral GAs. Fragmentation of tissues was a common finding in Acropora acuminata and Montipora cf. dilatata colonies with tissue loss, although no obvious causative agents were seen. Discoloration in the zoanthid, Palythoa tuberculosa, was found to be the result of necrosis, while in Lobophytum sp. discoloration was the result of zooxanthellar depletion (bleaching). Soft corals with discoloration or tissue loss showed a marked inflammatory response, however no obvious causative organisms were seen. Lesions that appeared similar at the gross level were revealed to be distinct by microscopy, emphasizing the importance of histopathology.

  5. ASM-Triggered Too Observations of Kilohertz Oscillations in Three Atoll Sources

    NASA Technical Reports Server (NTRS)

    Kaaret, P.; Swank, Jean (Technical Monitor)

    2000-01-01

    Three Rossi Timing Explorer (RXTE) observations were carried out for this proposal based on target of opportunity triggers derived from the All-Sky Monitor (ASM) on RXTE. We obtained short observations of 4U1636-536 (15ks) and 4U1735-44 (23ks) and a longer observation of 4U0614+091 (117ks). Our analysis of our observations of the atoll neutron star x-ray binary 4U1735-44 lead to the discovery of a second high frequency quasiperiodic oscillation (QPO) in this source. These results were published in the Astrophysical Journal Letters. The data obtained on the source 4U0614+091 were used in a comprehensive study of this source, which will be published in the Astrophysical Journal. The data from this proposal were particularly critical for that study as they lead to the detection of the highest QPO frequency every found in the x-ray emission from an x-ray binary which will be important in placing limits on the equation of state of nuclear matter.

  6. Gross and microscopic morphology of lesions in Cnidaria from Palmyra Atoll, Central Pacific

    USGS Publications Warehouse

    Williams, Gareth J.; Work, Thierry M.; Aeby, Greta S.; Knapp, Ingrid S.; Davy, Simon K.

    2011-01-01

    We conducted gross and microscopic characterizations of lesions in Cnidaria from Palmyra Atoll, Central Pacific. We found growth anomalies (GA) to be the most commonly encountered lesion. Cases of discoloration and tissue loss were rare. GAs had a focal or multi-focal distribution and were predominantly nodular, exophytic, and umbonate. In scleractinians, the majority of GAs manifested as hyperplasia of the basal body wall (52% of cases), with an associated absence or reduction of polyp structure (mesenteries and filaments, actinopharynx and tentacles), and depletion of zooxanthellae in the gastrodermis of the upper body wall. In the soft corals Sinularia sp. and Lobophytum sp., GAs exclusively manifested as prominent hyperplasia of the coenenchyme with an increased density of solenia. In contrast to scleractinians, soft coral GAs displayed an inflammatory and necrotizing component with marked edema of the mesoglea, accompanied by infiltrates of variably-sized granular amoebocytes. Fungi, algae, sponges, and Crustacea were present in some scleractinian GAs, but absent in soft coral GAs. Fragmentation of tissues was a common finding in Acropora acuminata and Montipora cf. dilatata colonies with tissue loss, although no obvious causative agents were seen. Discoloration in the zoanthid, Palythoa tuberculosa, was found to be the result of necrosis, while in Lobophytum sp. discoloration was the result of zooxanthellar depletion (bleaching). Soft corals with discoloration or tissue loss showed a marked inflammatory response, however no obvious causative organisms were seen. Lesions that appeared similar at the gross level were revealed to be distinct by microscopy, emphasizing the importance of histopathology.

  7. Climate and Human Pressures on Fresh Groundwater in Coral Atoll Island Nations in the Pacific

    NASA Astrophysics Data System (ADS)

    White, I.; Falkland, T.; Perez, P.; Dray, A.; Overmars, M.; Metai, E.

    2004-12-01

    Population centres in low, coral atolls have water supply problems that are amongst the most acute in the world. Limited land areas and highly permeable soils severely restrict surface water storage, forcing heavy reliance on groundwater. Fresh groundwater is extremely vulnerable to contamination through both natural processes, such as seawater intrusion following storm surges, sea-level rise and droughts, and human activities, such as overpumping, sewerage and waste disposal. Restricted land areas and seawater intrusion also limit fresh groundwater quantities, particularly in frequent ENSO-related droughts. Demand for water is increasing due to natural population growth, inward migration and to growing urbanisation. There are few water professionals in many small island nations. Assessment of groundwater resources is inadequate and application of conventional hydrology often gives erroneous information, such as the assumption of potential evaporation from coconut trees. Water use for traditional and introduced crops competes with community water supplies. Limited resources and isolation restrict the potential for exports so that reliance on aid is systemic. The agendas of developed world aid institutions sometimes conflict with traditions and cultures of small island communities. At the core of water management problems are lack of resource assessment and demand and land tenure and conflicts between the requirements of urbanised societies and the traditional values and rights of subsistence communities. Reforms of governance and provision of water resource knowledge to communities are critical. Long-term, regional partnerships and tools for reducing conflicts over water resources are needed to promote self-reliance.

  8. Shallow seismic refraction used to map the hydrostratigraphy of Nukuoro Atoll, Micronesia

    NASA Astrophysics Data System (ADS)

    Ayers, Jerry F.

    1990-02-01

    Results from a shallow seismic-refraction survey on Nukuoro indicate that the distribution of fresh and brackish groundwater on that atoll island is controlled by a three-dimensional mosaic of carbonate facies. Each facies is characterized by a distinct seismic velocity which is dependent on the grain size, composition, and abundance of carbonate cement. The refraction survey further indicates that the upper saturated zone is composed of mostly unconsolidated sediments underlain by highly permeable, well-indurated limestone. The fresh-water lens and associated transition zone of fresh to saline groundwater occur within the upper unconsolidated sediments. Measurements of chloride-ion concentrations in water samples collected from sites across the island indicate an asymmetric fresh-water lens with the thickest part of the lens located near the lagoon shoreline. During the 1983 drought, saline water intruded into the island's central topographical depression where taro is cultivated. The intrusion was caused by tidal pumping (upward movement) of brackish water underlying a reef-flat plate, which forms a confining layer over a significant part of the island.

  9. Ages of subsurface stratigraphic intervals in the Quaternary of Enewetak Atoll, Marshall Islands

    NASA Astrophysics Data System (ADS)

    Szabo, B. J.; Tracey, J. I.; Goter, E. R.

    1985-01-01

    Drill cores of Enewetak Atoll, Marshall Islands, reveal six stratigraphic intervals, numbered in downward sequence, which represent vertical coral growth during Quaternary interglaciations. Radiocarbon dates indicate that the Holocene sea transgressed the emergent reef platform by about 8000 yr B.P. The reef grew rapidly upward (about 5 to 10 mm/yr) until about 6500 yr B.P. Afterward vertical growth slowed to about 0.5 mm/yr, then lateral development became dominant during the last several thousand years. The second interval is dated at 131,000 ± 3000 yr B.P. by uranium series. This unit correlates with oxygen-isotope substage 5e and with terrace VIIa of Huon Peninsula, New Guinea, and of Main Reef-2 terrace at Atauro Island. The third interval is not dated because corals were recrystallized and it is tentatively correlated with either oxygen-isotope stages 7 or 9. The age of the fourth interval is estimated at 454,000 ± 100,000 yr B.P. from measured {234U }/{238U } activity ratios. This unit is correlated with either oxygen-isotope stage 9, 11, or 13.

  10. Atmospheric trace elements at Enewetak Atoll. I Concentrations, sources, and temporal variability

    NASA Astrophysics Data System (ADS)

    Duce, R. A.; Arimoto, R.; Ray, B. J.; Unni, C. K.; Harder, P. J.

    1983-06-01

    The concentrations of 29 elements in aerosol particles collected in 1979 during Searex (Sea/Air Exchange) experiments at Enewetak Atoll (11 deg N, 162 deg E), in the tropical North Pacific, are measured. The concentrations of Na, Mg, Cl, K, Ca, and Br are dominated by marine sources; the elements have similar mass-size distributions, and their atmospheric concentration ratios (normalized to Na) are similar to the corresponding ratios in bulk seawater. Atmospheric inputs of aluminosilicate particles from crustal weathering are found to control the aerosol particle concentration of Al, Sc, Mn, Fe, Co, Cs, Ba, Ce, Eu, Hf, Ta, and Th. The mean concentrations of these crustally derived elements decrease by an average of 91 percent (+ or - 4.1 percent) from the local dry season (April to May) to the wet season (July to August); this general decrease is attributed to the abatement of dust storms in Asia. At times, the influx of dust from Asia dominates the concentrations of V, Cr, Rb, and Cu in aerosol particles, but when dust concentrations decrease, noncrustal sources for these elements manifest themselves.

  11. Metals in albatross feathers from Midway Atoll: Influence of species, age, and nest location

    SciTech Connect

    Burger, J.; Gochfeld, M.

    2000-03-01

    In this paper the authors examine the concentrations of metals (heavy metals, mercury, lead, cadmium, chromium, manganese, tin; and metalloids, arsenic and selenium), in the down and contour (body) feathers of half-grown young albatrosses, and contour feathers of one of their parents. They collected feathers from Laysan Diomedea immutabilis and black-footed Diomedea nigripes albatrosses from Midway Atoll in the central Pacific Ocean. The authors test the null hypotheses that there is no difference in metal levels as a function of species, age, feather type, and location on the island. Using linear regression they found significant models accounting for the variation in the concentrations of mercury, lead, cadmium, selenium, chromium, and manganese (but not arsenic or tin) as a function of feather type (all metals), collection location (all metals but lead), species (selenium only), and interactions between these factors. Most metals (except mercury, arsenic, and tin) were significantly higher in down than in the contour feathers of either chicks or adults. Comparing the two species, black-footed albatross chicks had higher levels of most elements (except arsenic) in their feathers and/or down. Black-footed adults had significantly higher levels of mercury and selenium. They also collected down and feathers from Laysan albatross chicks whose nests were close to buildings, including buildings with flaking lead paint and those that had been lead-abated.

  12. Hydroxylated and methylsulfonyl polychlorinated biphenyl metabolites in albatrosses from Midway Atoll, North Pacific Ocean

    SciTech Connect

    Klasson-Wehler, E.; Bergman, A.; Athanasiadou, M.

    1998-08-01

    Concentrations of hydroxylated metabolites of polychlorinated biphenyls (PCBs) (OH-PCBs) and methylsulfonyl metabolites of PCBs (MeSO{sub 2}-PCBs) were determined in plasma and liver of albatrosses collected from the Midway Atoll in the central North Pacific Ocean. The mean total concentrations of OH-PCBs in plasma of Laysan albatrosses (Diomedea immutabilis) and black-footed albatrosses (Diomedea nigripes) were 11.5 and 27.1 ng/g wet weight, respectively. Total concentrations of OH-PCBs were only one- to fivefold less than those of total PCBs. 4-hydroxy-2,2{prime},3,4{prime},5,5{prime},6-heptachlorinated biphenyl and 4-hydroxy-2,2{prime},3,4{prime},5,5{prime}-hexachlorinated biphenyl were the predominant polychlorinated biphenylols, constituting 70 to 90% of the total OH-PCBs. Concentrations of MeSO{sub 2}-PCBs in liver were between 10.6 and 77 ng/g, lipid weight, approximately 250 times less than those of total PCBs. The MeSO{sub 2}-PCBs congeners retained in the liver were dominated by those having the methylsulfonyl group in the 3-position.

  13. Modeling patterns of coral bleaching at a remote Central Pacific atoll.

    PubMed

    Williams, Gareth J; Knapp, Ingrid S; Maragos, James E; Davy, Simon K

    2010-09-01

    A mild bleaching event (9.2% prevalence) at Palmyra Atoll occurred in response to the 2009 ENSO, when mean water temperature reached 29.8-30.1 degrees C. Prevalence among both abundant and sparse taxa varied with no clear pattern in susceptibility relating to coral morphology. Seven taxon-specific models showed that turbidity exacerbated while prior exposure to higher background temperatures alleviated bleaching, with these predictors explaining an average 16.3% and 11.5% variation in prevalence patterns, respectively. Positive associations occurred between bleaching prevalence and both immediate temperature during the bleaching event (average 8.4% variation explained) and increased sand cover (average 3.7%). Despite these associations, mean unexplained variation in prevalence equalled 59%. Lower bleaching prevalence in areas experiencing higher background temperatures suggests acclimation to temperature stress among several coral genera, while WWII modifications may still be impacting the reefs via shoreline sediment re-distribution and increased turbidity, exacerbating coral bleaching susceptibility during periods of high temperature stress. Copyright 2010 Elsevier Ltd. All rights reserved.

  14. Whale shark economics: a valuation of wildlife tourism in South Ari Atoll, Maldives.

    PubMed

    Cagua, Edgar Fernando; Collins, Neal; Hancock, James; Rees, Richard

    2014-01-01

    Whale sharks attract large numbers of tourists, divers and snorkelers each year to South Ari Atoll in the Republic of Maldives. Yet without information regarding the use and economic extent of the attraction, it is difficult to prioritize conservation or implement effective management plans. We used empirical recreational data and generalized mixed statistical models to conduct the first economic valuation (with direct spend as the primary proxy) of whale shark tourism in Maldives. We estimated that direct expenditures for whale shark focused tourism in the South Ari Marine Protected Area for 2012 and 2013 accounted for US$7.6 and $9.4 million respectively. These expenditures are based on an estimate of 72,000-78,000 tourists who are involved in whale shark excursions annually. That substantial amount of income to resort owners and operators, and tourism businesses in a relatively small area highlights the need to implement regulations and management that safeguard the sustainability of the industry through ensuring guest satisfaction and whale shark conservation.

  15. Variations in Hip Shape Are Associated with Radiographic Knee Osteoarthritis: Cross-sectional and Longitudinal Analyses of the Johnston County Osteoarthritis Project.

    PubMed

    Nelson, Amanda E; Golightly, Yvonne M; Renner, Jordan B; Schwartz, Todd A; Liu, Felix; Lynch, John A; Gregory, Jenny S; Aspden, Richard M; Lane, Nancy E; Jordan, Joanne M

    2016-02-01

    Hip shape by statistical shape modeling (SSM) is associated with hip radiographic osteoarthritis (rOA). We examined associations between hip shape and knee rOA given the biomechanical interrelationships between these joints. Bilateral baseline hip shape assessments [for those with at least 1 hip with a Kellgren-Lawrence arthritis grading scale (KL) 0 or 1] from the Johnston County Osteoarthritis Project were available. Proximal femur shape was defined on baseline pelvis radiographs and evaluated by SSM, producing mean shape and continuous variables representing independent modes of variation (14 modes = 95% of shape variance). Outcomes included prevalent [baseline KL ≥ 2 or total knee replacement (TKR)], incident (baseline KL 0/1 with followup ≥ 2), and progressive knee rOA (KL increase of ≥ 1 or TKR). Limb-based logistic regression models for ipsilateral and contralateral comparisons were adjusted for age, sex, race, body mass index (BMI), and hip rOA, accounting for intraperson correlations. We evaluated 681 hips and 682 knees from 342 individuals (61% women, 83% white, mean age 62 yrs, BMI 29 kg/m(2)). Ninety-nine knees (15%) had prevalent rOA (4 knees with TKR). Lower modes 2 and 3 scores were associated with ipsilateral prevalent knee rOA, and only lower mode 3 scores were associated with contralateral prevalent knee rOA. No statistically significant associations were seen for incident or progressive knee rOA. Variations in hip shape were associated with prevalent, but not incident or progressive, knee rOA in this cohort, and may reflect biomechanical differences between limbs, genetic influences, or common factors related to both hip shape and knee rOA.

  16. Quantifying the association of radiographic osteoarthritis in knee or hip joints with other knees or hips: the Johnston County Osteoarthritis Project.

    PubMed

    Sayre, Eric C; Jordan, Joanne M; Cibere, Jolanda; Murphy, Louise; Schwartz, Todd A; Helmick, Charles G; Renner, Jordan B; Rahman, M Mushfiqur; Aghajanian, Jaafar; Kang, Weiqun; Badley, Elizabeth M; Kopec, Jacek A

    2010-06-01

    To quantify the association of radiographic osteoarthritis (ROA) in one knee or hip joint with other knee or hip joints. We analyzed baseline data from the Johnston County Osteoarthritis Project (n = 3068). We fit 4 models for left/right knee/hip. The Kellgren-Lawrence (KL) radiographic grade severity scale was KL 0/1 (no/questionable ROA), 2 (mild ROA), or 3/4 (moderate/severe ROA). We estimated associations between KL grade in contralateral joints and other joint sites (e.g., worst hip in knee models), adjusting for sex, race/ethnicity (African American/white), age, and measured body mass index, using cumulative odds logistic regression models. Interactions were investigated: race/ethnicity by sex; race/ethnicity and sex by the 2 explanatory variables. Contralateral joint KL grade was strongly associated with KL grade, with OR ranging from 9.2 (95% CI 7.1, 11.9) to 225.0 (95% CI 83.6, 605.7). In the left knee model, the contralateral joint association was stronger among African Americans than whites, but for the other models the associations by race/ethnicity were identical. Models examining other joint sites showed weaker but mostly statistically significant associations (OR 1.4 to 1.8). We found a strong multivariable-adjusted association between KL grades in contralateral knees and hips, and a modest association with the other joint site (e.g., knees vs hips). These results suggest that diagnosis of ROA in 1 large joint may be a marker for risk of multijoint ROA, and warrant interventions to reduce the incidence or severity of ROA at these other joints.

  17. Variations in hip shape are associated with radiographic knee osteoarthritis: cross-sectional and longitudinal analyses of the Johnston County Osteoarthritis Project

    PubMed Central

    Nelson, AE; Golightly, YM; Renner, JB; Schwartz, TA; Liu, F; Lynch, JA; Gregory, JS; Aspden, RM; Lane, NE; Jordan, JM

    2015-01-01

    Objective Hip shape by statistical shape modeling (SSM) is associated with hip radiographic OA (rOA); we examined associations between hip shape and knee rOA given the biomechanical inter-relationships between these joints. Methods Bilateral baseline hip shape assessments (for those with at least 1 hip with Kellgren-Lawrence grade [KLG] 0 or 1) from the Johnston County Osteoarthritis Project were available. Proximal femur shape was defined on baseline pelvis radiographs and evaluated by SSM, producing mean shape and continuous variables representing independent modes of variation (14 modes=95% of shape variance). Outcomes included prevalent (baseline KLG >=2 or total knee replacement [TKR]), incident (baseline KLG 0/1 with follow-up >=2), and progressive (KLG increase of >=1 or TKR) knee rOA. Limb-based logistic regression models for ipsilateral and contralateral comparisons were adjusted for age, sex, race, body mass index (BMI), and hip rOA, accounting for intra-person correlations. Results We evaluated 681 hips and 682 knees from 342 individuals (61% women, 82% white, mean age 62 years, BMI 29 kg/m2). Ninety-nine knees (15%) had prevalent rOA (4 knees with TKR). Lower mode 2 and 3 scores were associated with ipsilateral prevalent knee rOA; only lower mode 3 scores were associated with contralateral prevalent knee rOA. No statistically significant associations were seen for incident or progressive knee rOA. Conclusions Variations in hip shape were associated with prevalent, but not incident or progressive, knee rOA in this cohort, and may reflect biomechanical differences between limbs, genetic influences, or common factors related to both hip shape and knee rOA. PMID:26669914

  18. Joint‐specific hand symptoms and self‐reported and performance‐based functional status in African–Americans and Caucasians: The Johnston County Osteoarthritis Project

    PubMed Central

    Elliott, A L; Kraus, V B; Fang, F; Renner, J B; Schwartz, T A; Salazar, A; Huguenin, T; Hochberg, M C; Helmick, C G; Jordan, J M

    2007-01-01

    Objective To assess associations between joint‐specific hand symptoms and self‐reported and performance‐based functional status. Methods Participants were from the population‐based Johnston County Osteoarthritis Project. Symptoms in the distal interphalangeal (DIP), proximal interphalangeal (PIP), first carpometacarpal (CMC), and metacarpophalangeal (MCP) joints were assessed on a 30‐joint diagram of both hands. Self‐reported function was assessed by Health Assessment Questionnaire (HAQ) and performance‐based function by timed repeated chair stands and 8‐foot walk time. Separate multiple logistic regression models examined associations between symptoms in specific hand joint groups, symptoms in ⩾2 hand joint groups and number of symptomatic hand joints, and functional status measures, controlling for age, race/ethnicity, sex, body mass index, radiographic knee and hip OA, knee and hip symptoms and depressive symptoms. Results Those with symptomatic hand joint groups were more likely than those without these complaints to report more difficulty and require longer times for performance measures. Those with 2 or more symptomatic hand joint groups were more likely to have higher HAQ scores (OR = 1.97 (1.53 to 2.53)) and require more time to complete 5 chair stands (OR = 1.98 (1.23 to 3.18)) and the 8 foot walk test (OR = 1.49 (1.12 to 1.99)). Conclusions Joint‐specific hand symptoms are associated with difficulty performing upper‐ or lower‐extremity tasks, independent of knee and hip OA and symptoms, suggesting that studies examining functional status in OA should not ignore symptomatic joints beyond the joint site of interest, even when functional measures appear to be specific for the joint site under study. PMID:17504840

  19. Annual incidence rates of hip symptoms and three hip OA outcomes from a U.S. population-based cohort study: the Johnston County Osteoarthritis Project.

    PubMed

    Moss, A S; Murphy, L B; Helmick, C G; Schwartz, T A; Barbour, K E; Renner, J B; Kalsbeek, W; Jordan, J M

    2016-09-01

    Estimate annual incidence rates (IRs) of hip symptoms and three osteoarthritis (OA) outcomes (radiographic, symptomatic, and severe radiographic) overall and by race, sociodemographic characteristics, and hip OA risk factors. Analyze baseline (1991-1997) and first follow-up (1999-2003) data (n = 1446) from the Johnston County Osteoarthritis Project, a population-based, prospective study of adults ≥45 years in North Carolina. Hip symptoms were pain, aching, and/or stiffness on most days, or groin pain. Radiographic and severe radiographic OA were Kellgren-Lawrence (KL) grades ≥2 and ≥3, respectively. Symptomatic OA was radiographic OA with symptoms in the same hip. Sociodemographics were age, gender, race, highest attained education, and annual household income. Hip OA risk factors were self-reported body mass index (BMI) at age 18 years, clinically measured BMI at baseline, and history of hip injury. Annual IRs (median = 5.5 years follow-up) were 37, 23, 13, and 2.9 per 1000 person-years for hip symptoms, and radiographic, symptomatic, and severe radiographic hip OA, respectively. We found low IRs of radiographic and symptomatic hip OA among African Americans and high IRs of hip symptoms among the obese and the very poor. Across outcomes, IRs were highest for those with hip injury. No prior studies have reported IRs of hip symptoms; IRs of radiographic and severe radiographic hip OA were similar to, and the IR of symptomatic hip OA was higher than, previous estimates. Prevention efforts should target low socioeconomic status (SES) populations and obese adults; interventions for hip OA and hip symptoms are imperative for those with hip injuries. Published by Elsevier Ltd.

  20. A Fresh Look at the Geologic Evolution of Kingman Reef and Palmyra Atoll, U.S. Line Islands

    NASA Astrophysics Data System (ADS)

    Barth, G. A.; Eakins, B.; Scheirer, D. S.; Wong, F. L.; Jones, M. R.

    2013-12-01

    Extended continental shelf (ECS) interest has provided a vehicle for renewed scientific study of the geologic framework of the U.S. Line Islands. In support of ECS studies, GLORIA sidescan sonar imagery has been refreshed and re-released. New multibeam bathymetry and backscatter data and a compilation of bathymetric tracks of opportunity enhance the credibility of new backscatter interpretations. Two-channel seismic reflection data collected during the GLORIA program in 1991 have been reprocessed and compiled into a digital database and have yielded a new understanding of sediment distribution and basement morphology within the 200 nautical mile exclusive economic zone (EEZ) surrounding Kingman Reef and Palmyra Atoll. Kingman Reef and Palmyra Atoll are small islands today. We infer that they are the last subaerial remnants of what was once a complex volcanic island, made up of no fewer than 8 different volcanic centers and spanning roughly 200 km in total diameter. Edifice heights above the immediately surrounding volcanic basement exceed 3000 m, and in several cases exceed 4000 m. Voluminous sediment accumulations flanking these now-submerged and significantly buried edifices point to their past existence as shallow-water or emergent volcanic systems capable of producing large quantities of volcaniclastic as well as carbonate sediment quite different from the thinner layer of pelagic sediment blanketing the adjacent central Pacific deep sea floor. The sediment pond east of Palmyra Atoll, in a perched basin near the center of this ancient complex, exceeds 1200 m in thickness. The Kingman-Palmyra region today is a showcase of mass transport features, with rugged erosional topography on steep volcanic flanks, a collapsed or eroding carbonate platform covering part of the central complex, and wide, sinuous leveed channels sweeping predominantly toward the north, carrying sediment away from the remnant high and out onto the deep sea floor to the east of the Line

  1. Near-surface mixing and pronounced deep-water stratification in a compartmentalised, human-disturbed atoll lagoon system

    NASA Astrophysics Data System (ADS)

    Gardner, J. P. A.; Garton, D. W.; Collen, J. D.

    2011-03-01

    Palmyra Atoll has four partially isolated lagoons up to 50 m in depth, each with complex and variable bottom topographies. Measurements of depth, temperature, salinity, turbidity and dissolved oxygen (DO) revealed a well-mixed shallow surface layer (0-10 m depth) and below that pronounced stratification of DO in the absence of a pycnocline. Turbidity increased in a step-like manner at ~25 m depth, at the oxycline. For all deep sections of the lagoon (>30 m), DO declined uniformly to 0% saturation. As determined from filtration, mass of particulates was independent of depth. Surface mixing and deep-water stratification are both stable at different temporal scales, including day versus night, daily, weekly and annually. We suggest that lagoon circulation is represented by a shallow, westward-moving surface layer of well-to-partially mixed water with high DO and low turbidity, underlain by a relatively static and temporally stable layer with low to zero DO and elevated turbidity. This is the first report of such conditions within a deep lagoon system, and only the second report of anoxic conditions in any such system. In deep-water, stable euxinic conditions reflect bottom topography, with dysoxic and anoxic water being constrained within silled basins. The occurrence and depth of large volumes of sediment-laden and dysoxic/anoxic water need to be considered in management proposals designed to increase water flow through the lagoon. These novel water column conditions most probably arose as a consequence of military construction work, consistent with published reports of profound changes to the atoll during 1940-1945. If so, they highlight the need to better understand the possible consequences of cutting channels and modification of lagoon flow at many atolls across the central Pacific Ocean.

  2. Larval Dispersal Modeling of Pearl Oyster Pinctada margaritifera following Realistic Environmental and Biological Forcing in Ahe Atoll Lagoon

    PubMed Central

    Thomas, Yoann; Dumas, Franck; Andréfouët, Serge

    2014-01-01

    Studying the larval dispersal of bottom-dwelling species is necessary to understand their population dynamics and optimize their management. The black-lip pearl oyster (Pinctada margaritifera) is cultured extensively to produce black pearls, especially in French Polynesia's atoll lagoons. This aquaculture relies on spat collection, a process that can be optimized by understanding which factors influence larval dispersal. Here, we investigate the sensitivity of P. margaritifera larval dispersal kernel to both physical and biological factors in the lagoon of Ahe atoll. Specifically, using a validated 3D larval dispersal model, the variability of lagoon-scale connectivity is investigated against wind forcing, depth and location of larval release, destination location, vertical swimming behavior and pelagic larval duration (PLD) factors. The potential connectivity was spatially weighted according to both the natural and cultivated broodstock densities to provide a realistic view of connectivity. We found that the mean pattern of potential connectivity was driven by the southwest and northeast main barotropic circulation structures, with high retention levels in both. Destination locations, spawning sites and PLD were the main drivers of potential connectivity, explaining respectively 26%, 59% and 5% of the variance. Differences between potential and realistic connectivity showed the significant contribution of the pearl oyster broodstock location to its own dynamics. Realistic connectivity showed larger larval supply in the western destination locations, which are preferentially used by farmers for spat collection. In addition, larval supply in the same sectors was enhanced during summer wind conditions. These results provide new cues to understanding the dynamics of bottom-dwelling populations in atoll lagoons, and show how to take advantage of numerical models for pearl oyster management. PMID:24740288

  3. Reef fish diversity at Aldabra Atoll, Seychelles, during the five years following the 1998 coral bleaching event.

    PubMed

    Downing, Nigel; Buckley, Raymond; Stobart, Ben; Leclair, Larry; Teleki, Kristian

    2005-01-15

    Quantitative surveys of fish-species diversity were undertaken at 10 m and 20 m water depth on the outer reef at Aldabra Atoll, southern Seychelles, between November 1999 and May 2003. No significant changes in total fish-species diversity, numbers of families represented by these species, or numbers of pomacentrid or chaetodontid species were seen, contrary to fish-diversity changes seen on coral bleaching-impacted reefs elsewhere. The lack of additional anthropogenic pressures at remote Aldabara may make this system, and others like it, more tolerant of bleaching-related population changes.

  4. Cyclic avian mass mortality in the northeastern United States is associated with a novel orthomyxovirus.

    PubMed

    Allison, Andrew B; Ballard, Jennifer R; Tesh, Robert B; Brown, Justin D; Ruder, Mark G; Keel, M Kevin; Munk, Brandon A; Mickley, Randall M; Gibbs, Samantha E J; Travassos da Rosa, Amelia P A; Ellis, Julie C; Ip, Hon S; Shearn-Bochsler, Valerie I; Rogers, Matthew B; Ghedin, Elodie; Holmes, Edward C; Parrish, Colin R; Dwyer, Chris

    2015-01-15

    Since 1998, cyclic mortality events in common eiders (Somateria mollissima), numbering in the hundreds to thousands of dead birds, have been documented along the coast of Cape Cod, MA, USA. Although longitudinal disease investigations have uncovered potential contributing factors responsible for these outbreaks, detecting a primary etiological agent has proven enigmatic. Here, we identify a novel orthomyxovirus, tentatively named Wellfleet Bay virus (WFBV), as a potential causative agent of these outbreaks. Genomic analysis of WFBV revealed that it is most closely related to members of the Quaranjavirus genus within the family Orthomyxoviridae. Similar to other members of the genus, WFBV contains an alphabaculovirus gp64-like glycoprotein that was demonstrated to have fusion activity; this also tentatively suggests that ticks (and/or insects) may vector the virus in nature. However, in addition to the six RNA segments encoding the prototypical structural proteins identified in other quaranjaviruses, a previously unknown RNA segment (segment 7) encoding a novel protein designated VP7 was discovered in WFBV. Although WFBV shows low to moderate levels of sequence similarity to Quaranfil virus and Johnston Atoll virus, the original members of the Quaranjavirus genus, additional antigenic and genetic analyses demonstrated that it is closely related to the recently identified Cygnet River virus (CyRV) from South Australia, suggesting that WFBV and CyRV may be geographic variants of the same virus. Although the identification of WFBV in part may resolve the enigma of these mass mortality events, the details of the ecology and epidemiology of the virus remain to be determined. The emergence or reemergence of viral pathogens resulting in large-scale outbreaks of disease in humans and/or animals is one of the most important challenges facing biomedicine. For example, understanding how orthomyxoviruses such as novel influenza A virus reassortants and/or mutants emerge to

  5. Cyclic Avian Mass Mortality in the Northeastern United States Is Associated with a Novel Orthomyxovirus

    PubMed Central

    Ballard, Jennifer R.; Tesh, Robert B.; Brown, Justin D.; Ruder, Mark G.; Keel, M. Kevin; Munk, Brandon A.; Mickley, Randall M.; Gibbs, Samantha E. J.; Travassos da Rosa, Amelia P. A.; Ellis, Julie C.; Ip, Hon S.; Shearn-Bochsler, Valerie I.; Rogers, Matthew B.; Ghedin, Elodie; Holmes, Edward C.; Parrish, Colin R.; Dwyer, Chris

    2014-01-01

    ABSTRACT Since 1998, cyclic mortality events in common eiders (Somateria mollissima), numbering in the hundreds to thousands of dead birds, have been documented along the coast of Cape Cod, MA, USA. Although longitudinal disease investigations have uncovered potential contributing factors responsible for these outbreaks, detecting a primary etiological agent has proven enigmatic. Here, we identify a novel orthomyxovirus, tentatively named Wellfleet Bay virus (WFBV), as a potential causative agent of these outbreaks. Genomic analysis of WFBV revealed that it is most closely related to members of the Quaranjavirus genus within the family Orthomyxoviridae. Similar to other members of the genus, WFBV contains an alphabaculovirus gp64-like glycoprotein that was demonstrated to have fusion activity; this also tentatively suggests that ticks (and/or insects) may vector the virus in nature. However, in addition to the six RNA segments encoding the prototypical structural proteins identified in other quaranjaviruses, a previously unknown RNA segment (segment 7) encoding a novel protein designated VP7 was discovered in WFBV. Although WFBV shows low to moderate levels of sequence similarity to Quaranfil virus and Johnston Atoll virus, the original members of the Quaranjavirus genus, additional antigenic and genetic analyses demonstrated that it is closely related to the recently identified Cygnet River virus (CyRV) from South Australia, suggesting that WFBV and CyRV may be geographic variants of the same virus. Although the identification of WFBV in part may resolve the enigma of these mass mortality events, the details of the ecology and epidemiology of the virus remain to be determined. IMPORTANCE The emergence or reemergence of viral pathogens resulting in large-scale outbreaks of disease in humans and/or animals is one of the most important challenges facing biomedicine. For example, understanding how orthomyxoviruses such as novel influenza A virus reassortants and

  6. Atmospheric trace elements at Enewetak Atoll: 2. Transport to the ocean by wet and dry deposition

    NASA Astrophysics Data System (ADS)

    Arimoto, R.; Duce, R. A.; Ray, B. J.; Unni, C. K.

    1985-02-01

    The concentrations of trace elements in precipitation and dry deposition are presented for samples collected at Enewetak Atoll (11°N, 162° E) during SEAREX experiments in 1979. The concentrations of Al, Sc, Mn, Fe, Co, and Th in rain are dominated by crustal material, and for these elements, wet deposition evidently exceeds dry deposition. For most of these elements the present rates of atmospheric deposition at Enewetak are similar to their mean rate of accumulation in sediments over the past 5-10,000 years, suggesting that the air-to-sea exchange of particles is closely tied to the sedimentary cycle of the mid-Pacific. Noncrustal sources govern the concentrations of Pb, Zn, Cu, Se, and Cd in wet and dry deposition samples. Analyses of dry deposition collected from a flat plastic plate indicate that the amount of material recycled from the sea surface varies markedly between samples, and even though these estimates do not necessarily reflect the dry deposition to the ocean surface, the results suggest that recycled sea spray often amounts to more than 50% of the total dry deposition of the enriched elements. Recycled sea spray also makes up a significant fraction of the total wet deposition of the enriched elements. The net deposition rates of elements such as Cu and Zn are greater than or equal to their inputs from vertical mixing, but the net deposition of Pb clearly exceeds the input from upwelling. The current net deposition rates of the enriched elements are also similar to their rates of removal to sediments. These results indicate that air-sea exchange processes may significantly affect the chemistry of trace metals in the open ocean.

  7. Effects of marine overwash for atoll aquifers: environmental and human factors.

    PubMed

    Bailey, Ryan T; Jenson, John W

    2014-01-01

    Inundation of atoll islands by marine overwash is a serious threat to fresh groundwater, which can be a critical emergency water resource after artificial storage or other water resource infrastructure has been exhausted or destroyed. In contrast to drought, which slowly exhausts water supplies and often can be forecasted in time, overwash can occur with little warning and can ruin both rain catchment storage and groundwater reserves. In this study, a SUTRA-based model is applied to estimate how groundwater contamination by overwash and subsequent recovery of fresh groundwater are influenced by geologic factors (aquifer hydraulic conductivity, dispersivity, and the presence or absence of a reef flat plate), the seasonal timing of the event (wet vs. dry), and the presence of hand-dug wells that penetrate the reef flat plate. Actual tidal and rainfall data from regions in the western Pacific are applied to simulated 30-month recovery periods for hypothetical islands with properties and conditions characteristic of the western Pacific. For all scenarios, results indicate that 12 to 16 months are required to achieve 60% recovery of fresh groundwater. However, the time required to restore useful quantities of groundwater to acceptable salt concentration at depths typical of hand-dug wells is only 3 to 6 months. Of particular interest is the influence of the reef flat plate, which acts as a barrier to infiltrating seawater, thus preserving a pocket of confined freshwater during an overwash event and the recovery, which could probably be utilized if the necessary tools and equipment are on hand.

  8. Uncertainty analysis for an updated dose assessment for a US nuclear test site: Bikini Atoll

    SciTech Connect

    Bogen, K.T.; Conrado, C.L.; Robison, W.L.

    1995-11-01

    A detailed analysis of uncertainty and interindividual variability in estimated doses was conducted for a rehabilitation scenario for Bikini Island at Bikini Atoll, in which the top 40 cm of soil would be removed in the housing and village area, and the rest of the island is treated with potassium fertilizer, prior to an assumed resettlement date of 1999. Predicted doses were considered for the following fallout-related exposure pathways: ingested Cesium-137 and Strontium-90, external gamma exposure, and inhalation and ingestion of Americium-241 + Plutonium-239+240. Two dietary scenarios were considered: (1) imported foods are available (IA), and (2) imported foods are unavailable (only local foods are consumed) (IUA). Corresponding calculations of uncertainty in estimated population-average dose showed that after {approximately}5 y of residence on Bikini, the upper and lower 95% confidence limits with respect to uncertainty in this dose are estimated to be approximately 2-fold higher and lower than its population-average value, respectively (under both IA and IUA assumptions). Corresponding calculations of interindividual variability in the expected value of dose with respect to uncertainty showed that after {approximately}5 y of residence on Bikini, the upper and lower 95% confidence limits with respect to interindividual variability in this dose are estimated to be approximately 2-fold higher and lower than its expected value, respectively (under both IA and IUA assumptions). For reference, the expected values of population-average dose at age 70 were estimated to be 1.6 and 5.2 cSv under the IA and IUA dietary assumptions, respectively. Assuming that 200 Bikini resettlers would be exposed to local foods (under both IA and IUA assumptions), the maximum 1-y dose received by any Bikini resident is most likely to be approximately 2 and 8 mSv under the IA and IUA assumptions, respectively.

  9. A dose assessment for a U.S. nuclear test site -- Bikini Atoll

    SciTech Connect

    Robison, W.L.; Bogen, K.T.; Conrado, C.L.

    1993-07-01

    On March 1, 1954, a nuclear weapon test, code-named BRAVO, conducted at Bikini Atoll in the northern Marshall Islands contaminated the major residence island. Here the authors provide a radiological dose assessment for the main residence island, Bikini, using extensive radionuclide concentration data derived from analysis of food crops, ground water, cistern water, fish and other marine species, animals, air, and soil collected at Bikini Island. The unique composition of coral soil greatly alters the relative contribution of cesium-137 and strontium-90 to the total estimated dose relative to expectations based on North American and European soils. Cesium-137 produces 96% of the estimated dose for returning residents, mostly through uptake from the soil to terrestrial food crops but also from external gamma exposure. The estimated maximum annual effective dose is 4.4 mSv y{sup {minus}1} when imported foods, which are now an established part of the diet, are available. The 30-, 50-, and 70-y integral effective doses are 10 cSv, 14 cSv, and 16 cSv, respectively. An analysis of interindividual variability in 0- to 30-y expected integral dose indicates that 95% of Bikini residents would have expected doses within a factor of 3.4 above and 4.8 below the population-average value. A corresponding uncertainty analysis showed that after about 5 y of residence, the 95% confidence limits on population-average dose would be {+-}35% of its expected value. The authors have evaluated various countermeasures to reduce {sup 137}Cs in food crops. Treatment with potassium reduces the uptake of {sup 137}Cs into food crops, and therefore the ingestion dose, to less than 10% of pretreatment levels and has essentially no negative environmental consequences.

  10. Past and present levels of some radionuclides in fish from Bikini and Enewetak atolls

    SciTech Connect

    Noshkin, V.E.; Robison, W.L.; Brunk, J.L.

    1997-07-01

    Bikini and Enewetak were the sites in the Northern Marshall Islands that were used by the United States as testing grounds for nuclear devices between 1946 and 1958. The testing produced close-in fallout debris that was contaminated with different radionuclides and which entered the aquatic environment. The contaminated lagoon sediments became a reservoir and source term of manmade radionuclides for the resident marine organisms. This report contains a summary of all the available data on the concentrations of {sup 137}Cs {sup 60}Co and {sup 217}Bi in flesh samples of reef and pelagic fish collected from Bikini and Enewetak Atolls between 1964 and 1995. The selection of these three radionuclides for discussion is based on the fact that these are the only radionuclides that have been routinely detected by gamma spectrometry in flesh samples from all fish for the last 20 y. Flesh from fish is an important source of food in the Marshallese diet. These radionuclides along with the transuranic radionuclides and {sup 90}Sr contribute most of the small radiological dose from ingesting marine foods. Some basic relationships among concentrations in different tissues and organs are discussed. The reef fish can be used as indicator species because their body burden is derived from feeding, over a lifetime, within a relatively small contaminated area of the lagoon. Therefore, the emphasis of this report is to use this extensive and unique concentration data base to describe the effective half lives and cycling for the radionuclides in the marine environments during the 31-y period between 1964 and 1995. 26 refs., 4 figs., 5 tabs.

  11. Ecological characteristics of coral patch reefs at Midway Atoll, Northwestern Hawaiian Islands

    USGS Publications Warehouse

    Schroeder, R.E.; Parrish, J.D.

    2006-01-01

    Ecological aspects of coral patch reefs were studied from 1981 to 1985 in Welles Harbor, Midway Atoll. Water temperatures varied from 17??C in February to 28??C in August. Sizes of reefs studied were described by mean area (59 m2), mean volume (52 m3), vertical relief (<1 m), and inter-reef isolation (100 m). Considerable temporal change in reef size occurred due to large winter swells shifting bottom sand. Six common species accounted for 70% of all individual fish visually censused over 4 years. Overall fish assemblage composition ranged from 11 to 46 fish/10 m2, from 3 to 14 species. Numerical abundance and species richness for all fish (pooled) strongly correlated with physical reef substrate characteristics of area, volume, and vertical relief during summer. Species diversity (H') was not correlated with the substrate variables, suggesting similarity in the structure of fish communities among different sizes of patch reefs. Daily surveillance for presence of large transient taxa suggested that visits by sharks, large jacks, monk seals, sea turtles, and dolphins were infrequent. Density estimates were made for all conspicuous invertebrate megafauna during initial and final assessments. Six common taxa provided 90% of these counts; nearly half were sea urchins. Percent cover also was recorded for coral and algal species on the patch reefs. Cover by live coral was low (about 7%) and dominated by a few species. Mean algal cover ranged from 32 to 77%. Such information on ecological characteristics of reefs may aid in understanding complex ecological processes and provides an earlier reference for current ecosystem studies.

  12. Gross and microscopic morphology of lesions in Cnidaria from Palmyra Atoll, Central Pacific.

    PubMed

    Williams, Gareth J; Work, Thierry M; Aeby, Greta S; Knapp, Ingrid S; Davy, Simon K

    2011-02-01

    We conducted gross and microscopic characterizations of lesions in Cnidaria from Palmyra Atoll, Central Pacific. We found growth anomalies (GA) to be the most commonly encountered lesion. Cases of discoloration and tissue loss were rare. GAs had a focal or multi-focal distribution and were predominantly nodular, exophytic, and umbonate. In scleractinians, the majority of GAs manifested as hyperplasia of the basal body wall (52% of cases), with an associated absence or reduction of polyp structure (mesenteries and filaments, actinopharynx and tentacles), and depletion of zooxanthellae in the gastrodermis of the upper body wall. In the soft corals Sinularia sp. and Lobophytum sp., GAs exclusively manifested as prominent hyperplasia of the coenenchyme with an increased density of solenia. In contrast to scleractinians, soft coral GAs displayed an inflammatory and necrotizing component with marked edema of the mesoglea, accompanied by infiltrates of variably-sized granular amoebocytes. Fungi, algae, sponges, and Crustacea were present in some scleractinian GAs, but absent in soft coral GAs. Fragmentation of tissues was a common finding in Acropora acuminata and Montipora cf. dilatata colonies with tissue loss, although no obvious causative agents were seen. Discoloration in the zoanthid, Palythoa tuberculosa, was found to be the result of necrosis, while in Lobophytum sp. discoloration was the result of zooxanthellar depletion (bleaching). Soft corals with discoloration or tissue loss showed a marked inflammatory response, however no obvious causative organisms were seen. Lesions that appeared similar at the gross level were revealed to be distinct by microscopy, emphasizing the importance of histopathology. Copyright © 2010 Elsevier Inc. All rights reserved.

  13. Atoll groundwater movement and its response to climatic and sea-level fluctuations

    USGS Publications Warehouse

    Oberle, Ferdinand; Swarzenski, Peter; Storlazzi, Curt

    2017-01-01

    Groundwater resources of low-lying atoll islands are threatened due to short-term and long-term changes in rainfall, wave climate, and sea level. A better understanding of how these forcings affect the limited groundwater resources was explored on Roi-Namur in the Republic of the Marshall Islands. As part of a 16-month study, a rarely recorded island-overwash event occurred and the island’s aquifer’s response was measured. The findings suggest that small-scale overwash events cause an increase in salinity of the freshwater lens that returns to pre-overwash conditions within one month. The overwash event is addressed in the context of climate-related local sea-level change, which suggests that overwash events and associated degradations in freshwater resources are likely to increase in severity in the future due to projected rises in sea level. Other forcings, such as severe rainfall events, were shown to have caused a sudden freshening of the aquifer, with salinity levels retuning to pre-rainfall levels within three months. Tidal forcing of the freshwater lens was observed in electrical resistivity profiles, high-resolution conductivity, groundwater-level well measurements and through submarine groundwater discharge calculations. Depth-specific geochemical pore water measurements further assessed and confirmed the distinct boundaries between fresh and saline water masses in the aquifer. The identification of the freshwater lens’ saline boundaries is essential for a quantitative evaluation of the aquifers freshwater resources and help understand how these resources may be impacted by climate change and anthropogenic activities.

  14. More coral, more fish? Contrasting snapshots from a remote Pacific atoll.

    PubMed

    Beldade, Ricardo; Mills, Suzanne C; Claudet, Joachim; Côté, Isabelle M

    2015-01-01

    Coral reefs are in decline across the globe as a result of overexploitation, pollution, disease and, more recently, climate change. The impacts of changes in coral cover on associated fish communities can be difficult to predict because of the uneven dependence of reef fish species on corals for food, shelter or the three-dimensional structure they provide. We compared live coral cover, reef fish community metrics, and their associations in two surveys of the lagoon of the remote atoll of Mataiva (French Polynesia) carried out 31 years apart. In contrast to the general pattern of decreasing coral cover reported for many parts of the Indo-Pacific region, live coral cover increased 6-7 fold at Mataiva between 1981 and 2012, and fish density nearly doubled. The stable overall reef fish species richness belied a significant shift in community structure. There was little overlap in community composition across years, and fish assemblages in 2012 were more homogeneous in composition than they were in 1981. Changes in species abundance were not clearly related to species-specific reliance on corals. The strong positive relationships between live coral cover and fish diversity and abundance noted in 1981, when coral cover rarely exceeded 10%, were no longer present in 2012, when coral cover rarely fell below this value. The most parsimonious explanation for these contrasting relationships is that, over the combined range of coral cover observed in the 1981 and 2012 snapshots, there is a rapidly asymptotic relationship between coral and fish. Our results, and other data from the south and west Pacific, suggest that fish diversity and abundance might accumulate rapidly up to a threshold of approximately 10% live coral cover. Such a relationship would have implications for our expectations of resistance and recovery of reef fish communities facing an increasingly severe regime of coral reef disturbances.

  15. An investigation into the prevalence of thyroid disease on Kwajalein Atoll, Marshall Islands

    SciTech Connect

    Takahashi, T.; Fujimori, K.; Kimura, N.

    1997-07-01

    The objective of the study was to obtain thyroid disease rate statistics on as much of the population as possible that was alive during the years of nuclear testing and to test the hypothesis that described a linearly decreasing prevalence of palpable nodules with increasing distance from the Bikini test site. 1,322 Marshallese born before 1965 were given a thyroid examination using neck palpation, fine needle aspiration biopsy, and high resolution ultrasound imaging. Approximately 40% of the total population living on this island who are at risk from exposure to radioactive fallout during the years 1946-1958 were screened. Of that group, 815 were alive at the time of the BRAVO test on 1 March 1954. Two hundred sixty-six people with thyroid nodules were found (32.6%): 132 were palpable nodules (16.2%), and 134 were nodules that could be diagnosed with ultrasound only (15.7%). Prevalence of palpable nodules was particularly high in men and women older than 60 y, in men who were 6 to 15 y of age at the time of the BRAVO test, and in women 1 to 10 y of age at the time of the BRAVO test. In 22 people, the clinical diagnosis was most likely cancer though histopathological evidence was only available from 11 operated cases. Of the 11 operated cases, 10 were cancer. Cancer prevalence was particularly high in those women born between 1944 and 1953 (7/220 = 3.2%), i.e., who were children during the early years of nuclear testing. The Ebeye data showed a marginally significant correlation between palpable nodule prevalence among women and distance to Bikini (r = -0.44, p = 0.06). This report summarizes the clinical findings of the thyroid examinations, the age distributions for nodular disease and cancer, and examines the relationship between prevalence of nodules and present day levels of {sup 137}Cs in the environment of each atoll. 22 refs., 4 figs., 9 tabs.

  16. Meteoric diagenesis, marine diagenesis, and microporosity in Pleistocene and Oligocene limestones, Enewetak Atoll, Marshall Islands

    NASA Astrophysics Data System (ADS)

    Saller, Arthur H.; Moore, Clyde H.

    1989-07-01

    Microporosity occurs in Pleistocene and Oligocene limestones cored on Enewetak Atoll. In cores of Pleistocene limestone (10-80 m deep), mi microporosity is present in aragonitic skeletal grains that underwent partial intrafabric dissolution (chalkification) leaving a porous meshwork of aragonite needles. Microporous aragonite is most abundant in 5-10 m thick intervals below zones of intense diagenesis associated with paleo-freshwater lenses. Extensive microporosity was apparently generated by slow intrafabric dissolution of aragonite in mixing zones below freshwater lenses. Microporous aragonite is an intermediate step in the calcitization or dissolution of aragonite. Most calcitized aragonite (neomorphic calcite) formed by precipitation of sparry calcite in (over) microporous aragonite. Aragonitic fossils were not converted to microporous, microcrystalline calcite. Therefore, data from the Pleistocene of Enewetak suggest that widespread, microporous, microcrystalline calcite does not form directly from pure aragonite, at least not in open meteoric systems or mixing zones. Microporous micrite occurs in Oligocene wackestones 930 m deep deposited in a slope environment. The microporous micrite is characterized by equant and prismatic crystals of low-magnesium calcite (LMC). Equant crystals are anhedral to euhedral and 2-10 μm in diameter. Prismatic calcite crystals are subhedral, 5-10 μm wide, and 20-50 μm long. Stable isotopic and trace element geochemistry suggest that microporous micrite formed by diagenetic alteration of high-magnesium calcite (HMC) micrite in deep seawater undersaturated with respect to HMC but supersaturated with respect to LMC (probably near the sediment-water interface). Mineralogy and crystal morphology of the microporous aragonite is very different from microporous shelf limestones in the Thamama Group (Cretaceous, Persian Gulf; see Moshier, 1989). Equant microcrystals of calcite in the Oligocene micrites are similar to those in

  17. Evaluating Satellite Rainfall Retrievals for Tropical Convective Regimes: Case Analysis from Kwajalein Atoll

    NASA Astrophysics Data System (ADS)

    Henderson, D.; Kummerow, C. D.

    2015-12-01

    Validation of oceanic retrieved rainfall from satellite remains a difficult task due to limited surfaced-based observations of precipitation. Currently, the dual-polarimetric S-band radar located on the Kwajalein Atoll (KPOL) is the only fully continuous operational radar in a tropical ocean setting - making the Kwajalein site an invaluable tool for evaluating tropical oceanic precipitation retrievals from the TRMM and GPM missions. Perturbations in oceanic rainfall during El Niño time periods lead to large discrepancies in passive and active microwave rainfall retrievals, which are linked to regional variations in convective organization (i.e. changes in isolated convection and mesoscale convective systems). The Kwajalein ground validation program provides the opportunity to validate the instantaneous TRMM rain products as a function of convective regime. To investigate regime-based relationships, multiple case studies are observed from 2008-2014 encompassing shallow convection, deep isolated convection, organized convection, and stratiform precipitation. The main objectives are to observe which rain rates retrieved from either PR or TMI algorithms are in agreement with KPOL-derived values and if distinct biases exist between TMI and PR as a function of convective regime. Among the cases examined, biases with KPOL are largest in deep isolated convection for TMI and PR retrievals. Furthermore, TMI tends to overestimate PR and KPOL estimations in broad stratiform precipitation. Examination of the GPROF rain rate retrieval and a comparison with rain estimates from the GPM core satellite will be used to further investigate the differences between the TRMM and KPOL-derived rain rates.

  18. Coral communities of the remote atoll reefs in the Nansha Islands, southern South China Sea.

    PubMed

    Zhao, M X; Yu, K F; Shi, Q; Chen, T R; Zhang, H L; Chen, T G

    2013-09-01

    During the months of May and June in the year 2007, a survey was conducted regarding coral reef communities in the remote atolls (Zhubi Reef and Meiji Reef) of Nansha Islands, southern South China Sea. The goals of the survey were to: (1) for the first time, compile a scleractinian coral check-list; (2) estimate the total richness, coral cover, and growth forms of the community; and (3) describe preliminary patterns of community structure according to geomorphological units. Findings of this survey revealed a total of 120 species of scleractinia belonging to 40 genera, while the average coral cover was 21 %, ranging from less than 10 % to higher than 50 %. Branching and massive corals were also found to be the most important growth forms of the whole coral community, while Acropora, Montipora, and Porites were the three dominant genera in the overall region, with their contributions to total coral cover measuring 21, 22, and 23 %, respectively. Overall, coral communities of the Nansha Islands were in a relative healthy condition with high species diversity and coral cover. Spatial pattern of coral communities existed among various geomorphological units. Mean coral cover was highest in the patch reef within the lagoon, followed by the fore reef slope, reef flat, and lagoon slope. The greatest contributors to total coral cover were branching Acropora (45 %) in the lagoon slope, branching Montipora (44 %) in the reef flat, and massive Porites (51 %) in the patch reef. Coral cover in the fore reef revealed a greater range of genera than in other habitats. The leeward fore reef slope had higher coral cover (> 50 %) when compared with the windward slope (< 10 %). The coral communities of the inner reef flat were characterized by higher coral cover (27 %) and dominant branching Montipora corals, while lower coral cover (4 %) was dominated by Psammocora with massive growth forms on the outer reef flat. Destructive fishing and coral bleaching were two major threats to

  19. Genetic diversity of Wolbachia endosymbionts in Culex quinquefasciatus from Hawai`i, Midway Atoll, and Samoa

    USGS Publications Warehouse

    Atkinson, Carter T.; Watcher-Weatherwax, William; Lapointe, Dennis

    2016-01-01

    Incompatible insect techniques are potential methods for controlling Culex quinquefasciatus and avian disease transmission in Hawai‘i without the use of pesticides or genetically modified organisms. The approach is based on naturally occurring sperm-egg incompatibilities within the Culex pipiens complex that are controlled by different strains of the bacterial endosymbiont Wolbachia pipientis (wPip). Incompatibilities can be unidirectional (crosses between males infected with strain A and females infected with strain B are fertile, while reciprocal crosses are not) or bidirectional (reciprocal crosses between sexes with different wPip strains are infertile). The technique depends on release of sufficient numbers of male mosquitoes infected with an incompatible wPip strain to suppress mosquito populations and reduce transmission of introduced avian malaria (Plasmodium relictum) and Avipoxvirus in native forest bird habitats. Both diseases are difficult to manage using more traditional methods based on removal and treatment of larval habitats and coordination of multiple approaches may be needed to control this vector. We characterized the diversity of Wolbachia strains in C. quinquefasciatus from Hawai‘i, Kaua‘i, Midway Atoll, and American Samoa with a variety of genetic markers to identify compatibility groups and their distribution within and between islands. We confirmed the presence of wPip with multilocus sequence typing, tested for local genetic variability using 16 WO prophage genes, and identified similarities to strains from other parts of the world with a transposable element (tr1). We also tested for genetic differences in ankyrin motifs (ank2 and pk1) which have been used to classify wPip strains into five worldwide groups (wPip1–wPip5) that vary in compatibility with each other based on experimental crosses. We found a mixture of both widely distributed and site specific genotypes based on presence or absence of WO prophage and transposable

  20. [Evidence of benzo-3, 4-pyrene in the water and organic sediments of briny pools of polynesian atolls. Biotic and abiotic factors].

    PubMed

    Niaussat, P M; Trichet, J; Heros, M; Luong, N T; Ehrhardt, J P

    1975-10-06

    The presence of 3,4-benzopyrene is reported in samples of water and sediments from three briny ponds free from pollution of exogenous origin belonging to three different atolls of Polynesia. The synthesis of this hydrocarbon seems to be dependent on the presence of abundant phytoplancton and of bacterial flora.

  1. Polychlorinated Biphenyls in the Plasma and Preen Oil of Black-Footed Albatross (Diomedea nigripes) Chicks and Adults on Midway Atoll, North Pacific Ocean

    PubMed Central

    Wang, Jun; Caccamise, Sarah A. L.; Woodward, Lee Ann; Li, Qing X.

    2015-01-01

    Polychlorinated biphenyls (PCBs) are ubiquitous in the environment. Midway Atoll, located in the North Pacific Ocean, was occupied by the military during and after World War II. However, Midway Atoll has become a national wildlife refuge and home to many different seabirds today, including the black-footed albatross (Diomedea nigripes) (BFAL). The profiles and toxic equivalents (TEQ) of PCB congeners in the plasma and preen oil of BFAL chicks and adults were determined in this study. The concentrations of the total PCBs in the plasma samples of chicks and adults collected in Midway Atoll ranged from 2.3 to 223.8 (mean 80.1) and 22.8 to 504.5 (mean 158.6) ng g-1 (wet weight, ww), respectively. The TEQs ranged from 0.2 to 0.6 (mean 0.4) and 0.4 to 1.6 (mean 0.9) pg g-1 ww, respectively, in the plasma samples of chicks and adults from Midway Atoll. The major congeners in the plasma samples of chicks and adults included PCBs 31, 87, 97, 99, 118, 138, 153, and 180, accounting for 70% of the total PCBs. The concentrations of the total PCBs in the adult preen oil samples ranged from 1693 to 39404 (mean 10122) ng g-1 (ww), of which 97% were PCBs 105, 118, 128, 138, 153, 161, 172, and 183. PMID:25901941

  2. Polychlorinated Biphenyls in the Plasma and Preen Oil of Black-Footed Albatross (Diomedea nigripes) Chicks and Adults on Midway Atoll, North Pacific Ocean.

    PubMed

    Wang, Jun; Caccamise, Sarah A L; Woodward, Lee Ann; Li, Qing X

    2015-01-01

    Polychlorinated biphenyls (PCBs) are ubiquitous in the environment. Midway Atoll, located in the North Pacific Ocean, was occupied by the military during and after World War II. However, Midway Atoll has become a national wildlife refuge and home to many different seabirds today, including the black-footed albatross (Diomedea nigripes) (BFAL). The profiles and toxic equivalents (TEQ) of PCB congeners in the plasma and preen oil of BFAL chicks and adults were determined in this study. The concentrations of the total PCBs in the plasma samples of chicks and adults collected in Midway Atoll ranged from 2.3 to 223.8 (mean 80.1) and 22.8 to 504.5 (mean 158.6) ng g(-1) (wet weight, ww), respectively. The TEQs ranged from 0.2 to 0.6 (mean 0.4) and 0.4 to 1.6 (mean 0.9) pg g(-1) ww, respectively, in the plasma samples of chicks and adults from Midway Atoll. The major congeners in the plasma samples of chicks and adults included PCBs 31, 87, 97, 99, 118, 138, 153, and 180, accounting for 70% of the total PCBs. The concentrations of the total PCBs in the adult preen oil samples ranged from 1693 to 39404 (mean 10122) ng g(-1) (ww), of which 97% were PCBs 105, 118, 128, 138, 153, 161, 172, and 183.

  3. Nuclear weapons produced (236)U, (239)Pu and (240)Pu archived in a Porites Lutea coral from Enewetak Atoll.

    PubMed

    Froehlich, M B; Tims, S G; Fallon, S J; Wallner, A; Fifield, L K

    2017-05-16

    A slice from a Porites Lutea coral core collected inside the Enewetak Atoll lagoon, within 15 km of all major nuclear tests conducted at the atoll, was analysed for (236)U, (239)Pu and (240)Pu over the time interval 1952-1964 using a higher time resolution than previously reported for a parallel slice from the same core. In addition two sediment samples from the Koa and Oak craters were analysed. The strong peaks in the concentrations of (236)U and (239)Pu in the testing years are confirmed to be considerably wider than the flushing time of the lagoon. This is likely due to the growth mechanism of the coral. Following the last test in 1958 atom concentrations of both (236)U and (239)Pu decreased from their peak values by more than 95% and showed a seasonal signal thereafter. Between 1959 and 1964 the weighted average of the (240)Pu/(239)Pu atom ratio is 0.124 ± 0.008 which is similar to that in the lagoon sediments (0.129 ± 0.006) but quite distinct from the global fallout value of ∼0.18. This, and the high (239,240)Pu and (236)U concentrations in the sediments, provides clear evidence that the post-testing signal in the coral is dominated by remobilisation of the isotopes from the lagoon sediments rather than from global fallout. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Predicting connectivity of green turtles at Palmyra Atoll, central Pacific: a focus on mtDNA and dispersal modelling

    USGS Publications Warehouse

    Naro-Maciel, Eugenia; Gaughran, Stephen J.; Putman, Nathan F.; Amato, George; Arengo, Felicity; Dutton, Peter H.; McFadden, Katherine W.; Vintinner, Erin C.; Sterling, Eleanor J.

    2014-01-01

    Population connectivity and spatial distribution are fundamentally related to ecology, evolution and behaviour. Here, we combined powerful genetic analysis with simulations of particle dispersal in a high-resolution ocean circulation model to investigate the distribution of green turtles foraging at the remote Palmyra Atoll National Wildlife Refuge, central Pacific. We analysed mitochondrial sequences from turtles (n = 349) collected there over 5 years (2008–2012). Genetic analysis assigned natal origins almost exclusively (approx. 97%) to the West Central and South Central Pacific combined Regional Management Units. Further, our modelling results indicated that turtles could potentially drift from rookeries to Palmyra Atoll via surface currents along a near-Equatorial swathe traversing the Pacific. Comparing findings from genetics and modelling highlighted the complex impacts of ocean currents and behaviour on natal origins. Although the Palmyra feeding ground was highly differentiated genetically from others in the Indo-Pacific, there was no significant differentiation among years, sexes or stage-classes at the Refuge. Understanding the distribution of this foraging population advances knowledge of green turtles and contributes to effective conservation planning for this threatened species.

  5. Predicting connectivity of green turtles at Palmyra Atoll, central Pacific: a focus on mtDNA and dispersal modelling

    PubMed Central

    Naro-Maciel, Eugenia; Gaughran, Stephen J.; Putman, Nathan F.; Amato, George; Arengo, Felicity; Dutton, Peter H.; McFadden, Katherine W.; Vintinner, Erin C.; Sterling, Eleanor J.

    2014-01-01

    Population connectivity and spatial distribution are fundamentally related to ecology, evolution and behaviour. Here, we combined powerful genetic analysis with simulations of particle dispersal in a high-resolution ocean circulation model to investigate the distribution of green turtles foraging at the remote Palmyra Atoll National Wildlife Refuge, central Pacific. We analysed mitochondrial sequences from turtles (n = 349) collected there over 5 years (2008–2012). Genetic analysis assigned natal origins almost exclusively (approx. 97%) to the West Central and South Central Pacific combined Regional Management Units. Further, our modelling results indicated that turtles could potentially drift from rookeries to Palmyra Atoll via surface currents along a near-Equatorial swathe traversing the Pacific. Comparing findings from genetics and modelling highlighted the complex impacts of ocean currents and behaviour on natal origins. Although the Palmyra feeding ground was highly differentiated genetically from others in the Indo-Pacific, there was no significant differentiation among years, sexes or stage-classes at the Refuge. Understanding the distribution of this foraging population advances knowledge of green turtles and contributes to effective conservation planning for this threatened species. PMID:24451389

  6. Distribution, Sources and Risk Assessment of Polychlorinated Biphenyls in Soils from the Midway Atoll, North Pacific Ocean

    PubMed Central

    Ge, Jing; Woodward, Lee Ann; Li, Qing X.; Wang, Jun

    2013-01-01

    Concentrations of 28 polychlorinated biphenyls (PCBs) were assessed in soils from the Midway Atoll in the central North Pacific Ocean. The analytical procedure involved the application of accelerated solvent extraction (ASE) and gas chromatography coupled with ion trap mass spectrometric detection (GC/ITMS) for identification and quantification. Among the 28 PCB congeners studied, 26 of them, except CB195 and CB209, were detected in the analyzed samples at different frequencies. The total concentrations of 28 indicator PCBs (ΣPCBs) ranged from 2.6 to 148.8 ng g−1 with an average value of 50.7 ng g−1 and median of 39.5 ng g−1. Sources and congeners’ pattern of PCB were investigated in the soil of Midway Atoll. The principal component analysis indicated that the compositions of PCBs in most of the soil samples were similar. The total concentrations of PCBs were used to assess the cancer risk probabilities in humans via ingestion, dermal contact and inhalation of soil particles. Very low cancer risk was found in all soil samples caused by ΣPCBs. PMID:23951182

  7. The natural history of Caroline Atoll, Southern Line Islands. Part I. History, physiography, botany, and isle descriptions

    USGS Publications Warehouse

    Kepler, A.K.; Kepler, C.B.

    1994-01-01

    conclusion: Lushly wooded Caroline Atoll, with the majority of its 39 islets (399 ha of land) either in near-pristine condition or having recovered remarkably from past disturbance, is one of the least spoiled atolls in the Pacific. Uninhabited, it harbors plant ecosystems and breeding seabirds (Pt. II) of national and international importance. Its marine and terrestrial ecosystems are prime outdoor ecological laboratories for research on geological processes including ground water, sea level changes, the dynamics of motu formation, fish poisoning, and numerous facets of ecology including plant succession and Pisonia growth rates. Caroline boasts prime coral reefs thickly studded with Tridacna clams, substantial numbers of coconut crabs, breeding sites for green turtles, wintering grounds for shorebirds including the rare Bristle-thighed Curlew, ancient Tuamotuan marae, and a crystalline, unpolluted lagoon. The variety, abundance, and quality of its flora and fauna qualify it for status as an officially recognized international preserve (Pt. II, Sect. G). Efforts toward its conservation have thus far been unsuccessful: in 1992 it was leased to a private French businessman who is currently fishing the reefs for commercial profit, as well as disturbing seabird, turtle and coconut crab populations.

  8. The natural history of Caroline Atoll, Southern Line Islands. Part II. Seabirds, other terrestrial animals, and conservation

    USGS Publications Warehouse

    Kepler, C.B.; Kepler, A.K.; Ellis, D.H.

    1994-01-01

    conclusion: Lushly wooded Caroline Atoll, with the majority of its 39 islets (399 ha of land) either in near-pristine condition or having recovered remarkably from past disturbance, is one of the least spoiled atolls in the Pacific. Uninhabited, it harbors plant ecosystems and breeding seabirds (Pt. II) of national and international importance. Its marine and terrestrial ecosystems are prime outdoor ecological laboratories for research on geological processes including ground water, sea level changes, the dynamics of motu formation, fish poisoning, and numerous facets of ecology including plant succession and Pisonia growth rates. Caroline boasts prime coral reefs thickly studded with Tridacna clams, substantial numbers of coconut crabs, breeding sites for green turtles, wintering grounds for shorebirds including the rare Bristle-thighed Curlew, ancient Tuamotuan marae, and a crystalline, unpolluted lagoon. The variety, abundance, and quality of its flora and fauna qualify it for status as an officially recognized international preserve (Pt. II, Sect. G). Efforts toward its conservation have thus far been unsuccessful: in 1992 it was leased to a private French businessman who is currently fishing the reefs for commercial profit, as well as disturbing seabird, turtle and coconut crab populations.

  9. [Reef fishes community structure in 4 atolls of the San Andrés - Providencia Archipelago (Southwestern Caribbean)].

    PubMed

    Mejía, L S; Garzón-Ferreira, J

    2000-12-01

    In 1994 and 1995, 131 visual censuses of reef fishes were made using the stationary sampling method in Courtown, Albuquerque, Serrana and Roncador, four atolls of the Archipelago of San Andrés and Old Providence in the Southwestern Caribbean. Fish species and their abundances were recorded in four geomorphologic zones: lagoon, windward barrier reef, windward terrace and forereef terrace. A total of 98 species were censused; the most abundant were Chromis cyanea (14%), Clepticus parra (14%) and Stegastes partitus (10%). The most abundant families were Pomacentridae (37%), Labridae (28%) and Scaridae (10%). Analysis of similarities showed that differences between zones were greater than differences between atolls, but lagoon and forereef terrace were not significantly different. Cluster and ordination analysis confirmed these results; in addition, the ordination analysis placed the groups according to depth and wave-exposure gradients, suggesting that these two physical variables were responsibles for the clustering. Differences in equitability and species richness appear also due to these variables. Inverse analysis showed in each group few characteristic species, then the differences between zones were due specially to dominance of some species. The dominant trophic categories were planktivorous and herbivorous that were significantly different between zones. In shallow zones (shallow lagoonal patch reefs) and high wave-exposed zones (winward barrier reef) dominated herbivorous fishes, while in deeper zones (terraces and deep lagoonal patch reefs) planktivorous were more abundant.

  10. Petrologic and geochemical constraints on the origin of subsurface dolomite, Enewetak Atoll: An example of dolomitization by normal seawater

    NASA Astrophysics Data System (ADS)

    Saller, Arthur H.

    1984-04-01

    Dolomite is present 1,250 1,400 m below sea level in Eocene strata of Enewetak Atoll. Petrographically, the deep Enewetak dolomite postdates brittle compaction of rigid grains in the host Eocene strata. The 87Sr/86Sr ratio of these dolomites (0.70865 0.70901) indicates that they formed at one or more times between the middle Miocene and the present. Since the top of the lower Miocene is more than 900 m above the deep dolomitic interval, the dolomite must have formed at a minimum burial depth of 900 m. Stable-oxygen-isotope determinations suggest dolomite precipitation from cold marine water. Lower Miocene and Eocene carbonate strata on the atoll are apparently in open communication with cold, modern ocean water, suggesting that those same strata were in open communication with ocean water during dolomitization. At a depth of about 1,000 m, modern Pacific Ocean water becomes undersaturated with respect to calcite but is still supersaturated with respect to dolomite. Therefore, it is proposed that the deep Enewetak dolomite precipitated from cold, deep ocean water (undersaturated with respect to calcite) at a burial depth of more than 900 m.

  11. Predicting connectivity of green turtles at Palmyra Atoll, central Pacific: a focus on mtDNA and dispersal modelling.

    PubMed

    Naro-Maciel, Eugenia; Gaughran, Stephen J; Putman, Nathan F; Amato, George; Arengo, Felicity; Dutton, Peter H; McFadden, Katherine W; Vintinner, Erin C; Sterling, Eleanor J

    2014-04-06

    Population connectivity and spatial distribution are fundamentally related to ecology, evolution and behaviour. Here, we combined powerful genetic analysis with simulations of particle dispersal in a high-resolution ocean circulation model to investigate the distribution of green turtles foraging at the remote Palmyra Atoll National Wildlife Refuge, central Pacific. We analysed mitochondrial sequences from turtles (n = 349) collected there over 5 years (2008-2012). Genetic analysis assigned natal origins almost exclusively (approx. 97%) to the West Central and South Central Pacific combined Regional Management Units. Further, our modelling results indicated that turtles could potentially drift from rookeries to Palmyra Atoll via surface currents along a near-Equatorial swathe traversing the Pacific. Comparing findings from genetics and modelling highlighted the complex impacts of ocean currents and behaviour on natal origins. Although the Palmyra feeding ground was highly differentiated genetically from others in the Indo-Pacific, there was no significant differentiation among years, sexes or stage-classes at the Refuge. Understanding the distribution of this foraging population advances knowledge of green turtles and contributes to effective conservation planning for this threatened species.

  12. A comparison of static versus dynamic models of sea-level rise impacts to atolls: Insights from the Northwestern Hawaiian Islands

    NASA Astrophysics Data System (ADS)

    Storlazzi, C. D.; Berkowitz, P.; Reynolds, M.; Logan, J. B.

    2012-12-01

    Two inundation events in 2011 underscored the potential for elevated water levels to damage infrastructure and impact terrestrial ecosystems on the low-lying Northwestern Hawaiian Islands in the Papahānaumokuākea Marine National Monument. The goal of this study was to compare passive GIS-based "bathtub" inundation models to those that include dynamic water levels caused by wave-induced set-up and run-up for two end-member island morphologies: Midway, a classic atoll with islets on the shallow (2-8 m) atoll rim and a deep, central lagoon; and Laysan, which is characterized by a deep (20-30 m) atoll rim and an islet at the center of the atoll. Vulnerability to elevated water levels was assessed using US Army Corps of Engineers hindcast wind and wave data to drive coupled Delft3D wave, current, and water level models for the atolls. The resulting model data were then used to compute run-up elevations using a parametric run-up equation under both present conditions and future sea-level rise scenarios. In both geomorphologies, wave heights and wavelengths adjacent to the islet shorelines increased more than three times and four times, respectively, with increasing values of sea-level rise, as more deep-water wave energy could propagate over the atoll rim and larger wind-driven waves could develop on the atoll. Although these increases in water depth resulted in decreased set-up, the larger wave heights and longer wavelengths due to sea-level rise increased the resulting wave-induced run-up. Run-up values were spatially heterogeneous and dependent on the direction of incident wave direction, bathymetry, and islet configuration. Islet inundation was modeled to increase substantially when wave-driven effects were included, suggesting that inundation and impacts to infrastructure and terrestrial habitats will occur at lower values of predicted sea-level rise, and thus sooner in the 21st century, than suggested by passive GIS-based "bathtub" inundation models.

  13. A history of the people of Bikini following nuclear weapons testing in the Marshall Islands: with recollections and views of elders of Bikini Atoll.

    PubMed

    Niedenthal, J

    1997-07-01

    The people of Bikini Atoll were moved from their homeland in 1946 to make way for the testing of 23 nuclear weapons by the United States government, beginning with the world's fourth atomic detonation. The subsequent half-century exodus of the Bikini people included a 2-y stay on Rongerik Atoll, where near starvation resulted, and a 6-mo sojourn on Kwajalein Atoll, where they lived in tents beside a runway used by the U.S. military. In 1948, they were finally relocated to Kili, a small, isolated, 200-acre island owned by the U.S. Trust Territory government. Numerous hardships have been faced there, not the least of which was the loss of skills required for self-sustenance. Located 425 miles south of Bikini, Kili Island is without a sheltered lagoon. Thus for six months of the year, fishing and sailing become futile endeavors. Because of the residual radioactive contamination from the nuclear testing, the majority of the Bikinian population still resides on Kili today. One attempt was made to resettle Bikini in the late 1960's when President Lyndon B. Johnson, on recommendations from the Atomic Energy Commission, declared Bikini Atoll safe for habitation. In 1978, however, it was discovered by the U.S. Department of Energy that in the span of only one year, some of the returned islanders were showing a 75% increase in their body burdens of 137Cs. In 1978, the people residing on Bikini were moved again, this time to a small island in Majuro Atoll. In the early 1980's, the Bikinians filed a class action lawsuit against the U.S. government for damages arising out of the nuclear testing program. Although the claim was dismissed, eventually a $90 million trust fund was established for their local government. Since then the leaders of the people of Bikini residing on Kili Island and Majuro Atoll have been confronted with the immense responsibility of determining how to clean their atoll while at the same time maintaining the health and welfare of their displaced

  14. Whole blood lead levels are associated with biomarkers of joint tissue metabolism in African American and White men and women: The Johnston County Osteoarthritis Project

    PubMed Central

    Nelson, Amanda E.; Chaudhary, Sanjay; Kraus, Virginia B.; Fang, Fang; Chen, Jiu-Chiuan; Schwartz, Todd A.; Shi, Xiaoyan A.; Renner, Jordan B.; Stabler, Thomas V.; Helmick, Charles G.; Caldwell, Kathleen; Poole, A. Robin; Jordan, Joanne M.

    2011-01-01

    Purpose To examine associations between biomarkers of joint tissue metabolism and whole blood lead (Pb), separately for men and women in an African American and Caucasian population, which may reflect an underlying pathology. Methods Participants in the Johnston County Osteoarthritis Project Metals Exposure Sub-study (329 men and 342 women) underwent assessment of whole blood Pb and biochemical biomarkers of joint tissue metabolism. Urinary cross-linked N telopeptide of type I collagen (uNTX-I) and C-telopeptide fragments of type II collagen (uCTX-II), and serum cleavage neoepitope of type II collagen (C2C), serum type II procollagen synthesis C-propeptide (CPII), and serum hyaluronic acid (HA) were measured using commercially available kits; the ratio of [C2C:CPII] was calculated. Serum cartilage oligomeric matrix protein (COMP) was measured by an in-house assay. Multiple linear regression models were used to examine associations between continuous blood Pb and biomarker outcomes, adjusted for age, race, current smoking status, and body mass index. Results are reported as estimated change in biomarker level for a 5-unit change in Pb level. Results The median Pb level among men and women was 2.2 and 1.9 µg/dL, respectively. Correlations were noted between Pb levels and the biomarkers uNTX-I, uCTX-II, and COMP in women, and between Pb and uCTX-II, COMP, CPII, and the ratio [C2C:CPII] in men. In adjusted models among women, a 5-unit increase in blood Pb level was associated with a 28% increase in uCTX-II and a 45% increase in uNTX-I levels (uCTX-II: 1.28 [95%CI: 1.04–1.58], uNTX-I: 1.45 [95%CI:1.21–1.74]). Among men, levels of Pb and COMP showed a borderline positive association (8% increase in COMP for a 5-unit change in Pb: 1.08 [95% CI: 1.00–1.18])); no other associations were significant after adjustment. Conclusions Based upon known biomarker origins, the novel associations between blood Pb and biomarkers appear to be primarily reflective of relationships

  15. Whole blood lead levels are associated with biomarkers of joint tissue metabolism in African American and white men and women: the Johnston County Osteoarthritis Project.

    PubMed

    Nelson, Amanda E; Chaudhary, Sanjay; Kraus, Virginia B; Fang, Fang; Chen, Jiu-Chiuan; Schwartz, Todd A; Shi, Xiaoyan A; Renner, Jordan B; Stabler, Thomas V; Helmick, Charles G; Caldwell, Kathleen; Poole, A Robin; Jordan, Joanne M

    2011-11-01

    To examine associations between biomarkers of joint tissue metabolism and whole blood lead (Pb), separately for men and women in an African American and Caucasian population, which may reflect an underlying pathology. Participants in the Johnston County Osteoarthritis Project Metals Exposure Sub-Study (329 men and 342 women) underwent assessment of whole blood Pb and biochemical biomarkers of joint tissue metabolism. Urinary cross-linked N telopeptide of type I collagen (uNTX-I) and C-telopeptide fragments of type II collagen (uCTX-II), serum cleavage neoepitope of type II collagen (C2C), serum type II procollagen synthesis C-propeptide (CPII), and serum hyaluronic acid (HA) were measured using commercially available kits; the ratio of [C2C:CPII] was calculated. Serum cartilage oligomeric matrix protein (COMP) was measured by an in-house assay. Multiple linear regression models were used to examine associations between continuous blood Pb and biomarker outcomes, adjusted for age, race, current smoking status, and body mass index. Results are reported as estimated change in biomarker level for a 5-unit change in Pb level. The median Pb level among men and women was 2.2 and 1.9μg/dL, respectively. Correlations were noted between Pb levels and the biomarkers uNTX-I, uCTX-II, and COMP in women, and between Pb and uCTX-II, COMP, CPII, and the ratio [C2C:CPII] in men. In adjusted models among women, a 5-unit increase in blood Pb level was associated with a 28% increase in uCTX-II and a 45% increase in uNTX-I levels (uCTX-II: 1.28 [95% CI: 1.04-1.58], uNTX-I: 1.45 [95% CI:1.21-1.74]). Among men, levels of Pb and COMP showed a borderline positive association (8% increase in COMP for a 5-unit change in Pb: 1.08 [95% CI: 1.00-1.18]); no other associations were significant after adjustment. Based upon known biomarker origins, the novel associations between blood Pb and biomarkers appear to be primarily reflective of relationships to bone and calcified cartilage turnover

  16. Model for the Establishment of Modern Atolls during the Mid Brunhes MIS 12 to MIS 11 Sea Level Transgression in the Maldive Archipelago (Equatorial Indian Ocean)

    NASA Astrophysics Data System (ADS)

    Droxler, A. W.; Belopolsky, A. V.

    2003-12-01

    The Maldive archipelago consists of 22 main atolls characterized by a marginal rim surrounding a lagoon commonly less than 50-60 m deep, though some lagoons reach depths of more than 80 m. The overall evolution of the carbonate system in the Maldive Archipelago clearly shows that the slow subsidence of hypothetical volcanic edifices buried under the atolls cannot explain their typical ringed morphology. On the contrary, the atolls in the Maldives, as most likely the majority of the modern atolls, are probably young (less than 0.5 My old) carbonate edifices. Our research in the Maldives was developed based upon the interpretation of two Elf-Aquitaine and Royal Dutch Shell MCS grids, groundtruthed by ODP Site 716 and two deep exploration wells. Several seismic profiles across the modern atoll margins clearly illustrate a shift from middle Miocene-early Pliocene sigmoid lateral margin progradation of flat-topped carbonate banks to late Quaternary bank top vertical aggradation evolving into the modern atoll physiography. This well-marked transition is first illustrated by a regionally observed initial downward shift of the depositional system dated at 3.0-2.5 Ma. This downward shift of onlap and subsequent deposition in sedimentary wedges below the early Pliocene bank margins are explained by a late Pliocene-early Pleistocene (3.0-0.5 My) gradual sea level regression tied to the onset and successive expansions of major continental ice sheets in the northern Hemisphere. This regression is clearly defined in several Pliocene-Quaternary high resolution benthic isotope records, best proxy for ice volume variations in the past 5 My, at ODP sites such as 659, 677, 846, and 849.The early Pliocene flat-topped carbonate banks, exposed for about 2.5 My in the late Pliocene and early Pleistocene, were fully re-flooded for the first time at the glacial MIS 12 to interglacial MIS 11 transition. This sea level transgression is unique by its highest amplitude among the multiple sea

  17. Assessment of coastal erosion and quantification of land loss on Western Pacific atolls during the last 50 years

    NASA Astrophysics Data System (ADS)

    Taborosi, Danko; Zega, Mojca; Jenson, John W.

    2010-05-01

    The majority of islands in the tropical western Pacific are coral atolls. Most are inhabited by indigenous Micronesian populations. Local people have over the millennia developed coping strategies and response mechanisms to difficult natural conditions, including typhoons, erosion, giant swells, and flooding, as well as ensuing famines and epidemics. However, since 1990s residents of atolls in the region have been appealing for help. They indicate that their islands are being rapidly eroded along coastlines, land areas are becoming smaller, and taro patches and other vegetation are being damaged. Such concerns were corroborated by one sweeping assessment by South Pacific Applied Geoscience Commission in 1998, as well as various isolated field observations since. Evidence of recent coastal erosion is found locally on many islands, both on windward and leeward sides and ocean and lagoon facing shores. Examples include retreating modern beaches, exhumed beachrock, scouring and undercutting of vegetation, overhanging scarps, etc. In addition, a considerable number of uninhabited islets have been completely obliterated by storms in the recent past; unusually high tides and swells have swept over large populated islands, destroying homes and harming agriculture; and at least one atoll has been abandoned due to irrecoverable typhoon damage. Those problems have received much worldwide media coverage, in which they are generally presented as "sinking" of islands due to global climate change and accompanying sea level rise. In reality, modern atolls are now known to be artifacts of the Pacific mid-Holocene High-Stand, and no first-hand data are available from Pacific islands to discern what proportion of observed erosional phenomena are 1) due to local natural and anthropogenic coastal processes as opposed to global and regional changes, and 2) caused by continuous natural dynamics as opposed to episodic extreme events. It is clear that some islands are faring better than

  18. Oolite facies as a transitional unit in deepening-upward carbonate sequences in Atoll, Seamount, and Guyot settings in Pacific basin

    SciTech Connect

    Schlanger, S.O.

    1987-05-01

    Prior to 1968, ooids had not been described from shallow-water carbonate complexes deposited in atoll, seamount, or guyot settings in the Pacific basin. This apparent lack of an oolite facies in the Pacific was puzzling, considering the abundance of ooids in modern Bahamian settings and in the Phanerozoic record in general. Since 1968, Deep Sea Drilling Project operations, marine seismic stratigraphic studies, dredging on drowned atolls, and field studies of an emergent atoll have revealed the presence of a Cretaceous oolite limestone atop Ita Maitai Guyot, Paleocene ooids on Koko Seamount, late Paleocene to middle Eocene ooids on Ojin Seamount, Eocene ooids on Harrie Guyot, and Holocene oolite limestone on Malden Island. At Ita Maitai Guyot the oolite limestone overlies normal lagoon sediments and is overlain by deep-water pelagic carbonate. At Malden Island, which is an emergent atoll, 3550-year-old oolite limestone overlies a 125,000-year-old reef complex. At Harrie Guyot and at Koko and Ojin Seamounts, ooids are associated with drowned atoll reef and lagoon complexes. The paleolatitude of deposition of the oolite facies lay between 5/sup 0/S and 18/sup 0/N. In these settings the formation of the oolite facies was apparently related to a rapid rise in sea level that caused flooding of an antecedent reef complex which failed to keep up with the rise in sea level. In Pacific basin environments the oolite facies is a minor and temporally ephemeral one which accounts for its scarcity in the stratigraphic record from this region.

  19. Influences of wind-wave exposure on the distribution and density of recruit reef fishes at Kure and Pearl and Hermes Atolls, Northwestern Hawaiian Islands

    USGS Publications Warehouse

    DeMartini, E.E.; Zgliczynski, B.J.; Boland, R.C.; Friedlander, A.M.

    2009-01-01

    This paper describes the results of a field survey designed to test the prediction that the density of benthic juveniles of shallow-reef fishes is greater on wind-wave "exposed" sectors of a pair of isolated oceanic atolls (Kure, Pearl and Hermes) at the far northwestern end of the Hawaiian Islands, an archipelago in which east-northeasterly trade winds dominate onshore water flow and transport by surface currents. The densities of recruits (juveniles ???5 cm total length) were higher overall on windward versus leeward sectors of carbonate rock-rubble back reefs at both atolls, and the pattern was stronger for smaller (likely younger, more recently settled) recruits of four of the five most abundant species and the remainder pooled as an "Other" taxon. The windward-leeward disparity was four-fold greater at Pearl Hermes (the atoll with a three-fold longer perimeter) than at Kure. Resident predator biomass also was correlated with recruit densities, but habitat (benthic substratum) effects were generally weak. The distribution and abundance of recruits and juveniles of the primarily endemic reef fishes on shallow back reefs at these atolls appear partly influenced by relative rates of water flow over windward vs. leeward sectors of barrier reef and by the size, shape, and orientation of habitat parcels that filter out postlarval fishes with relatively weak swimming capabilities like labroids. Whole-reef geomorphology as well as fine-scale habitat heterogeneity and rugosity should be considered among the suite of many factors used to interpret observed spatial patterns of post-settlement juvenile fish distribution at atolls and perhaps some other tropical reefs. ?? The Author(s) 2009.

  20. Evaluating the fate of freshwater lenses on atoll islands after eustatic sea-level rise and cyclone-driven inundation: A modelling approach

    NASA Astrophysics Data System (ADS)

    Terry, James P.; Chui, Ting Fong May

    2012-05-01

    Dispersed human populations inhabiting remote atolls across the tropical Pacific Ocean are reliant on the viability of thin freshwater lenses (FWLs) contained within the island coralline sediments for their survival. Yet FWLs are uniquely fragile and easily damaged by saline intrusion. Eustatic sea-level rise (SLR) and sea flooding generated by intense tropical cyclones therefore pose special perils for continued existence on atolls. In this work, mathematical modelling is used to examine the effects on an atoll freshwater lens of various projected long-term SLR scenarios (10, 20, and 40 cm). A cyclone-driven wave washover event is then simulated in order to observe the responses and recovery of the FWL, subsequent to the SLR scenarios imposed. A key attribute of our model design is the inclusion of a topographic depression containing a low-lying fresh swamp in the atoll islet interior (which is often ignored), where seawater accumulates during inundation. Results indicate that a 40 cm SLR produces a major impact: the FWL decreases in thickness by approximately 50%, develops a brackish centre and contracts to a shrunken 'doughnut' morphology. Following cyclone inundation, observed salinity profiles are illuminating. Steep salinity gradients show how a strong saline plume forms at shallow depths, but also reveal the existence of an undisturbed fresh horizon beneath the salt plume under both present conditions and the modest 10 cm SLR scenario. Within the preserved fresh horizon, salt concentrations are maintained below 1.5 g/L (i.e. within usable limits) for at least a year. In contrast, the diminished freshwater lenses that exist after 20 and 40 cm SLR then exhibit far less resilience to saline damage over comparable post-cyclone timeframes. The findings point towards Pacific atolls becoming increasingly uninhabitable long before their complete submergence by sea-level rise, owing to irrecoverable groundwater salinisation seriously reducing the availability of

  1. Spatial distribution of organochlorine contaminants in soil, sediment, and fish in Bikini and Enewetak Atolls of the Marshall Islands, Pacific Ocean.

    PubMed

    Wang, Jun; Caccamise, Sarah A L; Wu, Liejun; Woodward, Lee Ann; Li, Qing X

    2011-08-01

    Several nuclear tests were performed at Enewetak and Bikini Atolls in the Marshall Islands between 1946 and 1958. The events at Bikini Atoll involved several ships that were tested for durability during nuclear explosions, and 24 vessels now rest on the bottom of the Bikini lagoon. Nine soil samples were collected from different areas on the two islands of the atoll, and eighteen sediment, nine fish, and one lobster were collected in the vicinity of the sunken ships. Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polychlorinated terphenyls (PCTs) in these samples were analyzed using gas chromatography/ion trap mass spectrometry (GC/ITMS). The average recoveries ranged from 78% to 104% for the different PCB congeners. The limits of detection (LOD) for PCBs, PCTs, DDE, DDT, and dieldrin ranged 10-50 pg g(-1). Some fish from Enewetak contained PCBs at a concentration range of 37-137 ng g(-1), dry weight (dw), and most of the soils from Enewetak showed evidence of PCBs (22-392 ng g(-1)dw). Most of the Bikini lagoon sediment samples contained PCBs, and the highest was the one collected from around the Saratoga, an aircraft carrier (1555 ng g(-1)dw). Some of the fish samples, most of the soil samples, and only one of the sediment samples contained 2,2-bis(4-chlorophenyl)-1,1-dichloroethylene (DDE) and PCBs. In addition to PCBs, the soils from Enewetak Atoll contained PCTs. PCTs were not detected in the sediment samples from Bikini Atoll. The results suggest local pollution sources of PCBs, PCTs, and OCPs.

  2. The role of high-energy events (hurricanes and/or tsunamis) in the sedimentation, diagenesis and karst initiation of tropical shallow water carbonate platforms and atolls

    NASA Astrophysics Data System (ADS)

    Bourrouilh-Le Jan, F. G.

    1998-06-01

    Karst morphology appears early, even during carbonate sediment deposition. Examples from modern to 125-ka-old sub-, inter- and supratidal sediments are given from the Bahamas (Atlantic Ocean) and from Tuamotuan atolls (southeastern Pacific Ocean), with mineralogical and hydrological analyses. Karstification is favoured by the aragonitic composition of bioclasts coming from the shallow marine bio-factory. Lithification by aragonite cements appears as a rim around carbonate deposits and dissolution and non-cementation start at the same time on modern supratidal deposits (Andros micrite or atoll coral rudite) and provoke the formation of a central depression on small or large carbonate platforms. In fact, this early solution of the centre of platforms is closely related to the location of each of the studied examples on hurricane tracks. High-energy events, such as hurricanes and tsunamis, affect sediment transport but hurricanes also affect diagenesis as a result of the enormous volume of freshwater carried and discharged along their paths. This couple, lithification-solution, is localised at sea level and accompanies sea-level fluctuations along the eustatic curve. Because of the precise location of hurricane action all around the Earth, early karstification by aragonite solution, cementation and supratidal carbonate sediment accumulations (high-energy trails) act together on all the platforms and atolls located inside the Tropics (23°27') between roughly 5°-10° and 25° on both hemispheres. However, early karstification acts alone on shallow carbonate platforms including atolls along the equatorial belt between 5°-10°N and 5°-10°S. These early steps of karstification are linked to the ocean-atmosphere interface due to the bathymetrical position of shallow carbonate platforms, including atolls. They lead to complex karstified emerged platforms, called high carbonate islands, where carbonate diagenesis, together with the development of bauxite- and/or a

  3. Forecasting the impact of storm waves and sea-level rise on Midway Atoll and Laysan Island within the Papahānaumokuākea Marine National Monument—a comparison of passive versus dynamic inundation models

    USGS Publications Warehouse

    Storlazzi, Curt D.; Berkowitz, Paul; Reynolds, Michelle H.; Logan, Joshua B.

    2013-01-01

    Two inundation events in 2011 underscored the potential for elevated water levels to damage infrastructure and affect terrestrial ecosystems on the low-lying Northwestern Hawaiian Islands in the Papahānaumokuākea Marine National Monument. The goal of this study was to compare passive "bathtub" inundation models based on geographic information systems (GIS) to those that include dynamic water levels caused by wave-induced set-up and run-up for two end-member island morphologies: Midway, a classic atoll with islands on the shallow (2-8 m) atoll rim and a deep, central lagoon; and Laysan, which is characterized by a deep (20-30 m) atoll rim and an island at the center of the atoll. Vulnerability to elevated water levels was assessed using hindcast wind and wave data to drive coupled physics-based numerical wave, current, and water-level models for the atolls. The resulting model data were then used to compute run-up elevations using a parametric run-up equation under both present conditions and future sea-level-rise scenarios. In both geomorphologies, wave heights and wavelengths adjacent to the island shorelines increased more than three times and four times, respectively, with increasing values of sea-level rise, as more deep-water wave energy could propagate over the atoll rim and larger wind-driven waves could develop on the atoll. Although these increases in water depth resulted in decreased set-up along the islands’ shorelines, the larger wave heights and longer wavelengths due to sea-level rise increased the resulting wave-induced run-up. Run-up values were spatially heterogeneous and dependent on the direction of incident wave direction, bathymetry, and island configuration. Island inundation was modeled to increase substantially when wave-driven effects were included, suggesting that inundation and impacts to infrastructure and terrestrial habitats will occur at lower values of predicted sea-level rise, and thus sooner in the 21st century, than suggested

  4. Hydrochemical evidences: Vulnerability of atoll aquifers in Western Indian Ocean to climate change

    NASA Astrophysics Data System (ADS)

    Chattopadhyay, Pallavi Banerjee; Singh, V. S.

    2013-07-01

    The study evaluates movement of the saltwater interface and ionic composition in the atoll aquifer system in response to natural recharge in Western Indian Ocean (WIO). Sea level rise owing to climate change is expected to have substantial impacts on the world's population living on or near the coast over the next century (Vorosmarty et al., 2000; Milly et al., 2005). Change in sea level is predominantly linked to inundation and saltwater intrusion in coastal aquifers (Döll, 2009). However the change in precipitation pattern as a possible clause for seawater intrusion is poorly established and is due for substantial studies. The Intergovernmental Panel on Climate Change (IPCC) report (2007) that projects the global sea level rise of 18 to 59 cm from 1990 to the 2090s, along with an unspecified amount that could come from changes in the large ice sheets covering Greenland and Antarctica, depicts a relatively much lower regional sea level rise in the WIO. In addition, the report signifies a reduction in annual precipitation rate in this region in agreement with past historical data. This characterizes the WIO region as a potential critical zone under the influence of climate change (i.e. less sea level rise, high reduction in rainfall pattern) unlike most of its neighboring regions. The WIO region is a home to hundreds of coral islands and is inhabited largely. Despite its purported importance, tracing of the aquifer geometry under the influence of climate change has not been reported much. Application of hydro-chemical analysis to delineate the climate change impacts has even been rare. Androth island of Lakshadweep archipelago has been chosen as the study area. The study establishes that hydro-chemical evidences have a high degree of correlation between groundwater aquifer geometry and rate of precipitation. It depicts that decreasing trend in precipitation in the WIO region would result in seawater intrusion and significant shrinkage of aquifer geometry. The

  5. Geologic reconnaissance of natural fore-reef slope and a large submarine rockfall exposure, Enewetak Atoll

    SciTech Connect

    Halley, R.B.; Slater, R.A.

    1987-05-01

    In 1958 a submarine rockfall exposed a cross section through the reef and fore-reef deposits along the northwestern margin of Enewetak Atoll, Marshall Islands. Removal of more than 10/sup 8/ MT of rock left a cirque-shaped submarine scarp 220 m high, extending back 190 m into the modern reef, and 1000 m along the reef trend. The scarp exposed older, steeply dipping beds below 220 m along which the rockfall detached. They sampled this exposure and the natural fore-reef slope surrounding it in 1984 and 1985 using a manned submersible. The natural slope in this area is characterized by three zone: (1) the reef plate, crest, and near fore reef that extends from sea level to -16 m, with a slope of less than 10/sup 0/, (2) the bypass slope that extends from -16 to -275 m, with slopes of 55/sup 0/ decreasing to 35/sup 0/ near the base, and (3) a debris slope of less than 35/sup 0/ below -275 m. Vertical walls, grooves, and chutes, common on other fore-reef slopes, are sparse on the northwestern slope of Enewetak. The scarp exposes three stratigraphic units that are differentiated by surficial appearance: (1) a near-vertical wall from the reef crest to 76 m that appears rubbly, has occasional debris-covered ledges, and is composed mainly of coral; (2) a vertical to overhanging wall from -76 m to -220 m that is massive and fractured, and has smooth, blocky surfaces; and (3) inclined bedding below -220 m along which the slump block has fractured, exposing a dip slope of hard, dense, white limestone and dolomite that extends below -400 m. Caves occur in all three units. Open cement-lined fractures and voids layered with cements are most common in the middle unit, which now lies within the thermocline. Along the sides of the scarp are exposed fore-reef boulder beds dipping at 30/sup 0/ toward the open sea; the steeper (55/sup 0/) dipping natural surface truncates these beds, which gives evidence of the erosional nature of the bypass slope.

  6. The complex reality of sea-level rise in an atoll nation

    NASA Astrophysics Data System (ADS)

    Donner, S. D.

    2012-12-01

    Sea-level rise famously poses an existential threat to island nations like Kiribati, Tuvalu and the Maldives. Yet as the global mean sea-level rises, the response of any one location at any given time will depend on the natural variability in regional sea-level and other impact of local human activities on coastal processes. As with climate warming, the state of an individual shoreline or the extent of flooding on a given day is not proof of a sea-level trend, nor is a global sea-level trend a good predictor of individual flooding or erosion events. Failure to consider the effect of natural variability and local human activity on coastal processes often leads to misattribution of flooding events and even some long-term shoreline changes to global sea level rise. Moreover, unverified attribution of individual events or changes to specific islets to sea level rise can inflame or invite scepticism of the strong scientific evidence for an accelerating increase in the global sea level due to the impacts of human activity on the climate system. This is particularly important in developing nations like Kiribati, which are depending on international financial support to adapt to rising sea levels. In this presentation, I use gauge data and examples from seven years of field work in Tarawa Atoll, the densely populated capital of Kiribati, to examine the complexity of local sea level and shoreline change in one of the world's most vulnerable countries. First, I discuss how the combination of El Nino-driven variability in sea-level and the astronomical tidal cycle leads to flooding and erosion events which can be mistaken for evidence of sea-level rise. Second, I show that human modification to shorelines has redirected sediment supply, leading, in some cases, to expansion of islets despite rising sea levels. Taken together, the analysis demonstrates the challenge of attributing particular coastal events to global mean sea-level rise and the impact on decision-making. The

  7. Net community calcification and production rates from Palmyra Atoll using a boundary layer gradient flux approach

    NASA Astrophysics Data System (ADS)

    Takeshita, Y.; McGillis, W. R.; Martz, T. R.; Price, N.; Smith, J.; Donham, E. M.

    2016-02-01

    Coral reefs are a highly dynamic system, where large variability in environmental conditions (e.g. pH) occurs on timescales of minutes to hours. Yet, techniques that are capable of monitoring reef calcification rates without artificial confinement on the same frequency are scarce. Here, we present a 2 week time series of sub-hourly, in situ benthic net community production (Pnet) and net community calcification (Gnet) rates from a reef terrace at Palmyra Atoll using the Benthic Ecosystem and Acidification Monitoring System (BEAMS). The net metabolism rates reported here are measured under natural conditions, without any alterations to the environment (e.g. light, flow, pH). The BEAMS measures the chemical gradient and the current velocity profile in the benthic boundary layer using autonomous sensors to calculate the chemical flux from the benthos. The O2 and total alkalinity (TA) fluxes were used to calculate Pnet and Gnet, respectively; TA gradients were calculated from pH and O2 measurements. Gnet can be constrained to better than 3 mmol CaCO3 m-2 hr-1 using this approach, based on three simultaneous BEAMS deployments. A clear diel cycle of Gnet was observed, where the peak day time Gnet and average nighttime Gnet were 14 and 1 mmol CaCO3 m-2 hr-1, respectively. Integrated daily Gnet ranged from 76 to 219 mmol CaCO3 m-2 d-1, with an average of 107 ± 14 mmol CaCO3 m-2 d-1. Light had the strongest control over Gnet, with current velocity having a smaller yet noticeable effect. During the deployment, pH varied by 0.16 (ranged between 7.92 and 8.08), and a significant positive relationship was observed between pH and Gnet. However, pH was also positively correlated with current velocity and Pnet, making it difficult to determine if natural variability in pH was significantly affecting Gnet on the timescale of days to weeks.

  8. Environmental and ecological controls of coral community metabolism on Palmyra Atoll

    NASA Astrophysics Data System (ADS)

    Koweek, David; Dunbar, Robert B.; Rogers, Justin S.; Williams, Gareth J.; Price, Nichole; Mucciarone, David; Teneva, Lida

    2015-03-01

    Accurate predictions of how coral reefs may respond to global climate change hinge on understanding the natural variability to which these ecosystems are exposed and to which they contribute. We present high-resolution estimates of net community calcification (NCC) and net community production (NCP) from Palmyra Atoll, an uninhabited, near-pristine coral reef ecosystem in the central Pacific. In August-October 2012, we employed a combination of Lagrangian and Eulerian frameworks to establish high spatial (~2.5 km2) and temporal (hourly) resolution coral community metabolic estimates. Lagrangian drifts, all conducted during daylight hours, resulted in NCC estimates of -51 to 116 mmol C m-2 h-1, although most NCC estimates were in the range of 0-40 mmol C m-2 h-1. Lagrangian drift NCP estimates ranged from -7 to 67 mmol C m-2 h-1. In the Eulerian setup, we present carbonate system parameters (dissolved inorganic carbon, total alkalinity, pH, and pCO2) at sub-hourly resolution through several day-night cycles and provide hourly NCC and NCP rate estimates. We compared diel cycles of all four carbonate system parameters to the offshore surface water (0-50 m depth) and show large departures from offshore surface water chemistry. Hourly Eulerian estimates of NCC aggregated over the entire study ranged from 14 to 53 mmol C m-2 h-1, showed substantial variability during daylight hours, and exhibited a diel cycle with elevated NCC in the afternoons and depressed, but positive, NCC at night. The Eulerian NCP range was very high (-55 to 177 mmol C m-2 h-1) and exhibited strong variability during daylight hours. Principal components analysis revealed that NCC and NCP were most closely aligned with diel cycle forcing, whereas the NCC/NCP ratio was most closely aligned with reef community composition. Our analysis demonstrates that ecological community composition is the primary determinant of coral reef biogeochemistry on a near-pristine reef and that reef biogeochemistry is

  9. Chromium-isotope signatures in scleractinian corals from the Rocas Atoll, Tropical South Atlantic.

    PubMed

    Pereira, N S; Voegelin, A R; Paulukat, C; Sial, A N; Ferreira, V P; Frei, R

    2016-01-01

    Chromium-isotope compositions (expressed as δ(53) Cr) of recent and ancient skeletal and non-skeletal carbonates are currently explored as a (paleo-) redox-proxy for shallow seawater. The idea behind this approach is that biogenic and non-biogenic carbonates could potentially be used as archives recording the Cr-isotope composition of seawater in which they formed, and with this contribute to the reconstruction of past paleo-environmental changes in the marine realm, and potentially to climate changes on land. However, investigations addressing the behavior and uptake mechanism of Cr, and the potential isotope fractionations between seawater and biogenic carbonates are scarce. Here, we present a study of Cr-isotope variations in three species of corals and contemporary seawater from the Rocas Atoll, NE, Brazil. Cr-isotope values of the studied coral species (Siderastrea stellata, Porites sp., and Montastrea cavernosa) vary from -0.5 to +0.33‰ and point to significant isotopic disequilibrium with coexisting seawater characterized by a Cr-isotope value of +0.92 ± 0.2‰. This isotopic offset requires reduction of hexavalent Cr(VI) in the sequestration process of all the studied coral species. Cr-isotope values in a profile across an S. stellata colony returned homogeneous, slightly positively fractioned δ(53) Cr values of +0.07 ± 0.08‰ (n = 8, 2σ), which we interpret to reflect a constant reductive uptake during the 20-year growth period recorded in this coral. In contrast, samples across a 12-year growth profile from Porites sp. display rather heterogeneous Cr-isotope values with δ(53) Cr varying from -0.50 to +0.10‰, indicating Cr incorporation under changing redox processes during its growth intervals. We propose a mechanism whereby initial photoreduction of isotopically heavy Cr(VI) to isotopically lighter Cr(III) in the endodermal layer of corals must be followed by efficient and effective re-oxidation of reduced Cr species to favor subsequent

  10. Metals in albatross feathers from midway atoll: influence of species, age, and nest location.

    PubMed

    Burger, J; Gochfeld, M

    2000-03-01

    Female birds sequester some heavy metals in their eggs, which are then transferred to the developing embryo. Semiprecocial birds such as albatrosses are fully covered with down at hatching, but are dependent on their parents for food for many weeks. At hatching, levels of metals in the chick's down represent exposure from the female via egg, while levels in fully formed feathers at fledgling, several months later, represent mainly exposure from food provided by their parents. In this paper we examine the concentrations of "metals" (heavy metals, mercury, lead, cadmium, chromium, manganese, tin; and metalloids, arsenic and selenium), in the down and contour (body) feathers of half-grown young albatrosses, and contour feathers of one of their parents. We collected feathers from Laysan Diomedea immutabilis and black-footed Diomedea nigripes albatrosses from Midway Atoll in the central Pacific Ocean. We test the null hypotheses that there is no difference in metal levels as a function of species, age, feather type, and location on the island. Using linear regression we found significant models accounting for the variation in the concentrations of mercury, lead, cadmium, selenium, chromium, and manganese (but not arsenic or tin) as a function of feather type (all metals), collection location (all metals but lead), species (selenium only), and interactions between these factors. Most metals (except mercury, arsenic, and tin) were significantly higher in down than in the contour feathers of either chicks or adults. Comparing the two species, black-footed albatross chicks had higher levels of most elements (except arsenic) in their feathers and/or down. Black-footed adults had significantly higher levels of mercury and selenium. We also collected down and feathers from Laysan albatross chicks whose nests were close to buildings, including buildings with flaking lead paint and those that had been lead-abated. Lead levels in the down and feathers of chicks close to nonabated

  11. 5 CFR Appendix D to Subpart B of... - Nonappropriated Fund Wage and Survey Areas

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Application. Survey area. HAWAII Honolulu Survey Area Hawaii: Honolulu Area of Application. Survey area plus: Hawaii (counties): Hawaii Kauai Maui Pacific Islands: Midway Islands Johnston Atoll American Samoa IDAHO...

  12. 5 CFR Appendix D to Subpart B of... - Nonappropriated Fund Wage and Survey Areas

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Application. Survey area. HAWAII Honolulu Survey Area Hawaii: Honolulu Area of Application. Survey area plus: Hawaii (counties): Hawaii Kauai Maui Pacific Islands: Midway Islands Johnston Atoll American Samoa IDAHO...

  13. 32 CFR 212.3 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Northern Mariana Islands, the U.S. Virgin Islands, Guam, American Samoa, Johnston Atoll, Kingman Reef, Midway Island, Nassau Island, Palmyra Island, Wake Island, and any other territory or possession of...

  14. 5 CFR 610.202 - Determining the holiday.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... Virgin Islands; (5) Outer Continental Shelf Lands, as defined in the Outer Continental Shelf Lands Act (67 Stat. 462); (6) American Samoa; (7) Guam; (8) Midway Atoll; (9) Wake Island; (10) Johnston...

  15. 5 CFR 610.202 - Determining the holiday.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... Virgin Islands; (5) Outer Continental Shelf Lands, as defined in the Outer Continental Shelf Lands Act (67 Stat. 462); (6) American Samoa; (7) Guam; (8) Midway Atoll; (9) Wake Island; (10) Johnston...

  16. 5 CFR 610.202 - Determining the holiday.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    .... Virgin Islands; (5) Outer Continental Shelf Lands, as defined in the Outer Continental Shelf Lands Act (67 Stat. 462); (6) American Samoa; (7) Guam; (8) Midway Atoll; (9) Wake Island; (10) Johnston...

  17. 32 CFR 212.3 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Northern Mariana Islands, the U.S. Virgin Islands, Guam, American Samoa, Johnston Atoll, Kingman Reef, Midway Island, Nassau Island, Palmyra Island, Wake Island, and any other territory or possession of...

  18. 5 CFR 610.202 - Determining the holiday.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    .... Virgin Islands; (5) Outer Continental Shelf Lands, as defined in the Outer Continental Shelf Lands Act (67 Stat. 462); (6) American Samoa; (7) Guam; (8) Midway Atoll; (9) Wake Island; (10) Johnston...

  19. 5 CFR 610.202 - Determining the holiday.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... Virgin Islands; (5) Outer Continental Shelf Lands, as defined in the Outer Continental Shelf Lands Act (67 Stat. 462); (6) American Samoa; (7) Guam; (8) Midway Atoll; (9) Wake Island; (10) Johnston...

  20. 32 CFR 212.3 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Northern Mariana Islands, the U.S. Virgin Islands, Guam, American Samoa, Johnston Atoll, Kingman Reef, Midway Island, Nassau Island, Palmyra Island, Wake Island, and any other territory or possession of...

  1. Modeled Atoll Shoreline and Run-up Changes in Response to Sea-level Rise and Changing Wave Directions under Large Wave Conditions: Wake and Midway Atolls, Northwestern Hawaiian Islands

    NASA Astrophysics Data System (ADS)

    Shope, J. B.; Storlazzi, C. D.; Hoeke, R. K.

    2016-02-01

    Low-lying atoll islands are dynamic features expected to respond to changes in waves and sea level in a changing climate. Increased run-up and/or island erosion would threaten infrastructure and island communities. However, it is unclear how island erosion and run-up patterns will respond to climate change, making it difficult to prepare for the future. Large winter and summer wave conditions were modeled at two atolls, Wake and Midway in the Northwestern Hawaiian Islands, using Delft3D where sea level was varied at intervals between 0.0 to +2.0 m and incident wave directions from -15.0° to +15.0° from current conditions, to simulate potential climate change effects. The longshore sediment flux was calculated using the CERC empirical formulation and resulting potential erosion rates were calculated by the divergence of the longshore drift between scenarios; similarly, changes in run-up between scenarios were calculated using an empirical approach. The results are variable, but generally the ends of islands exhibit the most change under sea-level rise or rotating wave directions. Islands are projected to accrete on seaward, leeward, and lagoon shorelines due to sea-level rise, whereas island ends predominantly erode. Increases in run-up are greatest along island ends and smallest along seaward shorelines. Shorelines at the ends of islands show the greatest response to incident wave direction changes, whereas seaward and leeward shorelines become predominantly accretionary with an increasing wave angle. Run-up increases as shorelines become more directly exposed to incident waves; however, this response is greatest at the ends of islands. These simulations suggest island ends will experience the most morphological change and run-up increases due to climate change.

  2. Strontium isotope stratigraphy of Kita-daito-jima Atoll, North Philippine Sea: implications for Neogene sea-level change and tectonic history

    NASA Astrophysics Data System (ADS)

    Ohde, S.; Elderfield, H.

    1992-11-01

    A detailed chronology of a 432 m core from Kita-daito-jima, an atoll on the Philippine Sea plate, has been obtained by strontium isotope stratigraphy. The atoll carbonate extends to late Oligocene age. The top ˜ 100 m Plio-Pleistocene section of the core has been dolomitized, and dolomite also extends to middle Miocene sediments. Sr isotopes identify two dolomitization events, at ˜ 2 and ˜ 5 Ma. Atoll growth appears to have been continuous between 18.8 and 24.3 Ma and the fit of the growth history to a standard model provides a successful confirmation of Darwin's subsidence theory. The atoll growth appears to have commenced about 42 Ma ago (6 Ma after volcanism), producing a ˜ 2 km column of atoll carbonate, in agreement with bathymetry. The subsidence model defines an apparent loss of 360 m of the sedimentary record since the early-middle Miocene boundary. The amount in excess of the ˜ 100 m associated with sea-level fall is attributed to Plio-Pleistocene uplift at rates of ˜ 20-30 m/Ma associated with the forebulge of the Philippine Sea plate prior to its subduction. Uplift rates have also been estimated using (a) the heights of dated last-interglacial coral reefs on Kita-daito-jima and nearby Minami-daito-jima (˜ 17 m/Ma and ˜ 29 m/Ma), (b) Sr isotope ages of calcites from surface samples on Minami-daito-jima (˜ 21 m/Ma) and (c) contrasts in elevation with Okino-daito-jima 100 km away (˜ 22 m/Ma). The locations of hiatuses and ages of dolomitization indicate sea-level falls of ˜ 80 m at ˜ 17-16 Ma, ˜ 30 m at ˜ 16-15 Ma, ˜ 125 m at ˜ 11 Ma, and ˜ 90 m at ˜ 5 Ma and at ˜ 2 Ma. The data have been combined with those from Enewetak Atoll to produce a curve of sea-level change for the Neogene.

  3. Proximate environmental drivers of coral communities at Palmyra Atoll: establishing baselines prior to removing a WWII military causeway.

    PubMed

    Williams, Gareth J; Knapp, Ingrid S; Maragos, James E; Davy, Simon K

    2011-08-01

    A management proposal aims to partly remove a WWII military causeway at Palmyra Atoll to improve lagoon water circulation and alleviate sedimentation stress on the southeast backreef, an area of high coral cover and diversity. This action could result in a shift in sedimentation across reef sites. To provide management advice, we quantified the proximate environmental factors driving scleractinian coral cover and community patterns at Palmyra. The proportion of fine sedimentation was the optimal predictor of coral cover and changes in community structure, explaining 23.7% and 24.7% of the variation between sites, respectively. Scleractinian coral cover was negatively correlated with increases in fine sedimentation. Removing the causeway could negatively affect the Montipora corals that dominate the western reef terrace, as this genus was negatively correlated with levels of fine sedimentation. The tolerance limits of corals, and sediment re-distribution patterns, should be determined prior to complete removal of the causeway.

  4. Conservation management options and actions: putative decline of coral cover at Palmyra Atoll, Northern Line Islands, as a case study.

    PubMed

    Gardner, Jonathan P A; Bartz, R John; Brainard, Russell E; Collen, John D; Dunbar, Robert B; Garton, David W; Powell, Sam

    2014-07-15

    Localised loss of live coral cover at Palmyra Atoll (central Pacific Ocean) has been attributed to increased temperature and/or sedimentation arising from alterations made to the lagoon system. It has been hypothesised that a causeway spanning the lagoon hinders water circulation, resulting in warmer and/or more turbid water flowing towards a site of high coral cover and diversity (Coral Gardens). Analyses of a multi-site and multi-year data set revealed no differences in mean temperature or turbidity values on either side of the causeway and provided no evidence of significantly warmer or more turbid water at Coral Gardens. We conclude that the putative decline in live coral cover cannot be attributed to the presence of the causeway and that proposed management actions involving modification to the causeway cannot achieve the conservation outcomes suggested of them.

  5. Certified reference materials for radionuclides in Bikini Atoll sediment (IAEA-410) and Pacific Ocean sediment (IAEA-412).

    PubMed

    Pham, M K; van Beek, P; Carvalho, F P; Chamizo, E; Degering, D; Engeler, C; Gascó, C; Gurriaran, R; Hanley, O; Harms, A V; Herrmann, J; Hult, M; Ikeuchi, Y; Ilchmann, C; Kanisch, G; Kis-Benedek, G; Kloster, M; Laubenstein, M; Llaurado, M; Mas, J L; Nakano, M; Nielsen, S P; Osvath, I; Povinec, P P; Rieth, U; Schikowski, J; Smedley, P A; Suplinska, M; Sýkora, I; Tarjan, S; Varga, B; Vasileva, E; Zalewska, T; Zhou, W

    2016-03-01

    The preparation and characterization of certified reference materials (CRMs) for radionuclide content in sediments collected offshore of Bikini Atoll (IAEA-410) and in the open northwest Pacific Ocean (IAEA-412) are described and the results of the certification process are presented. The certified radionuclides include: (40)K, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (232)Th, (234)U, (238)U, (239)Pu, (239+240)Pu and (241)Am for IAEA-410 and (40)K, (137)Cs, (210)Pb ((210)Po), (226)Ra, (228)Ra, (228)Th, (232)Th, (235)U, (238)U, (239)Pu, (240)Pu and (239+240)Pu for IAEA-412. The CRMs can be used for quality assurance and quality control purposes in the analysis of radionuclides in sediments, for development and validation of analytical methods and for staff training.

  6. Necrotizing enteritis as a cause of mortality in Laysan albatross, Diomedea immutabilis, chicks on Midway Atoll, Hawaii

    USGS Publications Warehouse

    Work, T.M.; Smith, M.R.; Duncan, R.

    1998-01-01

    A necropsy survey of Laysan albatross, Diomedea immutabilis, chicks on Midway Atoll in June 1993, 1994, and 1995 revealed 54% (21/39), 67% (49/71), and 93% (15/16), respectively, to have enteritis as the most severe pathologic finding. The lesion was limited to the ileum, ceca, and large intestine. We were unable to attribute a single infectious etiology to this lesion. Many birds with enteritis also exhibited renal lesions similar to those encountered in chickens experimentally deprived of water. We propose that enteritis is a significant cause of mortality in Laysan albatross chicks on Midway and that it may be a sequela to dehydration. It is likely that the pathology of dehydration in Laysan albatross differs from that in chickens largely because of diet.

  7. Necrotizing enteritis as a cause of mortality in Laysan albatross, Diomedea immutabilis, chicks on Midway Atoll, Hawaii.

    PubMed

    Work, T M; Smith, M R; Duncan, R

    1998-01-01

    A necropsy survey of Laysan albatross, Diomedea immutabilis, chicks on Midway Atoll in June 1993, 1994, and 1995 revealed 54% (21/39), 67% (49/71), and 93% (15/16), respectively, to have enteritis as the most severe pathologic finding. The lesion was limited to the ileum, ceca, and large intestine. We were unable to attribute a single infectious etiology to this lesion. Many birds with enteritis also exhibited renal lesions similar to those encountered in chickens experimentally deprived of water. We propose that enteritis is a significant cause of mortality in Laysan albatross chicks on Midway and that it may be a sequela to dehydration. It is likely that the pathology of dehydration in Laysan albatross differs from that in chickens largely because of diet.

  8. Necrotizing enteritis as a cause of mortality in Laysan albatross, Diomedea immutabilis, chicks on Midway Atoll, Hawaii

    USGS Publications Warehouse

    Work, T.M.; Smith, M.R.; Duncan, R.

    1998-01-01

    A necropsy survey of Laysan albatross, Diomedea immutabilis, chicks on Midway Atoll in June 1993, 1994, and 1995 revealed 54% (21/39), 67% (49/71), and 93% (15/16), respectively, to have enteritis as the most severe pathologic finding. The lesion was limited to the ileum, ceca, and large intestine. We were unable to attribute a single infectious etiology to this lesion. Many birds with enteritis also exhibited renal lesions similar to those encountered in chickens experimentally deprived of water. We propose that enteritis is a significant cause of mortality in Laysan albatross chicks on Midway and that it may be a sequela to dehydration. It is likely that the pathology of dehydration in Laysan albatross differs from that in chickens largely because of diet.

  9. Drivers of abundance and spatial distribution of reef-associated sharks in an isolated atoll reef system

    PubMed Central

    Letessier, Tom B.; Koldewey, Heather J.; Meeuwig, Jessica J.

    2017-01-01

    We investigated drivers of reef shark demography across a large and isolated marine protected area, the British Indian Ocean Territory Marine Reserve, using stereo baited remote underwater video systems. We modelled shark abundance against biotic and abiotic variables at 35 sites across the reserve and found that the biomass of low trophic order fish (specifically planktivores) had the greatest effect on shark abundance, although models also included habitat variables (depth, coral cover and site type). There was significant variation in the composition of the shark assemblage at different atolls within the reserve. In particular, the deepest habitat sampled (a seamount at 70-80m visited for the first time in this study) recorded large numbers of scalloped hammerhead sharks (Sphyrna lewini) not observed elsewhere. Size structure of the most abundant and common species, grey reef sharks (Carcharhinus amblyrhynchos), varied with location. Individuals at an isolated bank were 30% smaller than those at the main atolls, with size structure significantly biased towards the size range for young of year (YOY). The 18 individuals judged to be YOY represented the offspring of between four and six females, so, whilst inconclusive, these data suggest the possible use of a common pupping site by grey reef sharks. The importance of low trophic order fish biomass (i.e. potential prey) in predicting spatial variation in shark abundance is consistent with other studies both in marine and terrestrial systems which suggest that prey availability may be a more important predictor of predator distribution than habitat suitability. This result supports the need for ecosystem level rather than species-specific conservation measures to support shark recovery. The observed spatial partitioning amongst sites for species and life-stages also implies the need to include a diversity of habitats and reef types within a protected area for adequate protection of reef-associated shark assemblages

  10. Drivers of abundance and spatial distribution of reef-associated sharks in an isolated atoll reef system.

    PubMed

    Tickler, David M; Letessier, Tom B; Koldewey, Heather J; Meeuwig, Jessica J

    2017-01-01

    We investigated drivers of reef shark demography across a large and isolated marine protected area, the British Indian Ocean Territory Marine Reserve, using stereo baited remote underwater video systems. We modelled shark abundance against biotic and abiotic variables at 35 sites across the reserve and found that the biomass of low trophic order fish (specifically planktivores) had the greatest effect on shark abundance, although models also included habitat variables (depth, coral cover and site type). There was significant variation in the composition of the shark assemblage at different atolls within the reserve. In particular, the deepest habitat sampled (a seamount at 70-80m visited for the first time in this study) recorded large numbers of scalloped hammerhead sharks (Sphyrna lewini) not observed elsewhere. Size structure of the most abundant and common species, grey reef sharks (Carcharhinus amblyrhynchos), varied with location. Individuals at an isolated bank were 30% smaller than those at the main atolls, with size structure significantly biased towards the size range for young of year (YOY). The 18 individuals judged to be YOY represented the offspring of between four and six females, so, whilst inconclusive, these data suggest the possible use of a common pupping site by grey reef sharks. The importance of low trophic order fish biomass (i.e. potential prey) in predicting spatial variation in shark abundance is consistent with other studies both in marine and terrestrial systems which suggest that prey availability may be a more important predictor of predator distribution than habitat suitability. This result supports the need for ecosystem level rather than species-specific conservation measures to support shark recovery. The observed spatial partitioning amongst sites for species and life-stages also implies the need to include a diversity of habitats and reef types within a protected area for adequate protection of reef-associated shark assemblages.

  11. The shark assemblage at French Frigate Shoals atoll, Hawai'i: species composition, abundance and habitat use.

    PubMed

    Dale, Jonathan J; Stankus, Austin M; Burns, Michael S; Meyer, Carl G

    2011-02-10

    Empirical data on the abundance and habitat preferences of coral reef top predators are needed to evaluate their ecological impacts and guide management decisions. We used longline surveys to quantify the shark assemblage at French Frigate Shoals (FFS) atoll from May to August 2009. Fishing effort consisted of 189 longline sets totaling 6,862 hook hours of soak time. A total of 221 sharks from 7 species were captured, among which Galapagos (Carcharhinus galapagensis, 36.2%), gray reef (Carcharhinus amblyrhynchos, 25.8%) and tiger (Galeocerdo cuvier, 20.4%) sharks were numerically dominant. A lack of blacktip reef sharks (Carcharhinus melanopterus) distinguished the FFS shark assemblage from those at many other atolls in the Indo-Pacific. Compared to prior underwater visual survey estimates, longline methods more accurately represented species abundance and composition for the majority of shark species. Sharks were significantly less abundant in the shallow lagoon than adjacent habitats. Recaptures of Galapagos sharks provided the first empirical estimate of population size for any Galapagos shark population. The overall recapture rate was 5.4%. Multiple closed population models were evaluated, with Chao M(h) ranking best in model performance and yielding a population estimate of 668 sharks with 95% confidence intervals ranging from 289-1720. Low shark abundance in the shallow lagoon habitats suggests removal of a small number of sharks from the immediate vicinity of lagoonal islets may reduce short-term predation on endangered monk seal (Monachus schauinslandi) pups, but considerable fishing effort would be required to catch even a small number of sharks. Additional data on long-term movements and habitat use of sharks at FFS are required to better assess the likely ecological impacts of shark culling.

  12. The Shark Assemblage at French Frigate Shoals Atoll, Hawai‘i: Species Composition, Abundance and Habitat Use

    PubMed Central

    Dale, Jonathan J.; Stankus, Austin M.; Burns, Michael S.; Meyer, Carl G.

    2011-01-01

    Empirical data on the abundance and habitat preferences of coral reef top predators are needed to evaluate their ecological impacts and guide management decisions. We used longline surveys to quantify the shark assemblage at French Frigate Shoals (FFS) atoll from May to August 2009. Fishing effort consisted of 189 longline sets totaling 6,862 hook hours of soak time. A total of 221 sharks from 7 species were captured, among which Galapagos (Carcharhinus galapagensis, 36.2%), gray reef (Carcharhinus amblyrhynchos, 25.8%) and tiger (Galeocerdo cuvier, 20.4%) sharks were numerically dominant. A lack of blacktip reef sharks (Carcharhinus melanopterus) distinguished the FFS shark assemblage from those at many other atolls in the Indo-Pacific. Compared to prior underwater visual survey estimates, longline methods more accurately represented species abundance and composition for the majority of shark species. Sharks were significantly less abundant in the shallow lagoon than adjacent habitats. Recaptures of Galapagos sharks provided the first empirical estimate of population size for any Galapagos shark population. The overall recapture rate was 5.4%. Multiple closed population models were evaluated, with Chao Mh ranking best in model performance and yielding a population estimate of 668 sharks with 95% confidence intervals ranging from 289–1720. Low shark abundance in the shallow lagoon habitats suggests removal of a small number of sharks from the immediate vicinity of lagoonal islets may reduce short-term predation on endangered monk seal (Monachus schauinslandi) pups, but considerable fishing effort would be required to catch even a small number of sharks. Additional data on long-term movements and habitat use of sharks at FFS are required to better assess the likely ecological impacts of shark culling. PMID:21347321

  13. Latitudinal limits to coral reef accretion: Testing the Darwin Point hypothesis at Kure Atoll, northwestern Hawaiian Islands, using new evidence from high resolution remote sensing and in situ data

    NASA Astrophysics Data System (ADS)

    Siciliano, Daria

    This dissertation focused on assessing patterns of carbonate production in a marginal reef environment as the key to understand the mechanisms that limit modern reef distribution, and those that effect the response of coral reefs to a changing environment. This investigation was carried out at Kure atoll in the Northwestern Hawaiian Islands, the northernmost atoll in the world. A less detailed comparative study was carried out throughout the 10 Northwestern Hawaiian Islands, with the goal of revisiting Grigg's (1982) Darwin Point hypothesis on the limit of coral reef formation. Patterns of carbonate metabolism and benthic diversity at Kure Atoll were obtained from analysis of high resolution IKONOS multispectral imagery; calcification rates were obtained from x-rayed slabs of coral samples and cores of the main coral reef-builders, collected in different habitats at Kure; data on habitat-specific bioerosion rates were obtained from in situ surveys of the main bioeroding taxa. These data were used to construct a habitat-specific carbonate budget for Kure Atoll. The main sources and sinks of CaCO3 at Kure Atoll were identified and their spatial extent quantified. Calcification rates vary significantly between the different habitats, with the warmer and wave-protected lagoonal patch reefs and back reef habitat exhibiting the largest growth rates. Average calcification rates were found to be one order of magnitude greater than those reported by Grigg (1982), as was the total amount of CaCO3 deposited by reef-building corals. The new habitat mapping techniques employed here show that the reef building area and amount of live coral cover in all three main geomorphic habitats of Kure Atoll is greater than previously estimated, and that the lagoonal environments of Kure Atoll contribute the greatest amount to the accretion potential of the atoll, followed by the actively accreting fore reef environment. Stable isotopic measurements indicate that the decrease in coral

  14. The entangled role of strain and diffusion in driving the spontaneous formation of atolls and holes in Ge/Si(111) heteroepitaxy

    NASA Astrophysics Data System (ADS)

    Persichetti, L.; Sgarlata, A.; Fanfoni, M.; Balzarotti, A.

    2013-10-01

    We investigate the interdependent processes of strain and diffusion in the formation of holes and atolls obtained by rapid annealing of Ge/Si(111) islands at T ≈ 970 °C. We show that the shape evolution from islands to atolls and holes is closely captured by an analytical model including strain-driven diffusion. In the model, strain profiles obtained by finite element solutions of continuum elasticity equations are introduced in the diffusion equation as the source of a diffusion flux driven by the strain gradient. When the shape of the elastic field in Ge/Si(111) islands is coupled to diffusion, the morphology of the SiGe nanostructures observed after annealing is reproduced.

  15. The entangled role of strain and diffusion in driving the spontaneous formation of atolls and holes in Ge/Si(111) heteroepitaxy.

    PubMed

    Persichetti, L; Sgarlata, A; Fanfoni, M; Balzarotti, A

    2013-10-02

    We investigate the interdependent processes of strain and diffusion in the formation of holes and atolls obtained by rapid annealing of Ge/Si(111) islands at T ≈ 970 °C. We show that the shape evolution from islands to atolls and holes is closely captured by an analytical model including strain-driven diffusion. In the model, strain profiles obtained by finite element solutions of continuum elasticity equations are introduced in the diffusion equation as the source of a diffusion flux driven by the strain gradient. When the shape of the elastic field in Ge/Si(111) islands is coupled to diffusion, the morphology of the SiGe nanostructures observed after annealing is reproduced.

  16. Spatial patterns of chemical contamination (metals, PAHs, PCBs, PCDDs/PCDFS) in sediments of a non-industrialized but densely populated coral atoll/small island state (Bermuda).

    PubMed

    Jones, Ross J

    2011-06-01

    There is a recognized dearth of standard environmental quality data in the wider Caribbean area, especially on coral atolls/small island states. Extensive surveys of sediment contamination (n=109 samples) in Bermuda revealed a wide spectrum of environmental quality. Zinc and especially copper levels were elevated at some locations, associated with boating (antifouling paints and boatyard discharges). Mercury contamination was surprisingly prevalent, with total levels as high as 12mg kg(-1)DW, although methyl mercury levels were quite low. PAH, PCB and PCDD/PCDF contamination was detected a several hotspots associated with road run-off, a marine landfill, and a former US Naval annexe. NOAA sediment quality guidelines were exceeded at several locations, indicating biological effects are possible, or at some locations probable. Overall, and despite lack of industrialization, anthropogenic chemicals in sediments of the atoll presented a risk to benthic biodiversity at a number of hotspots suggesting a need for sediment management strategies.

  17. Influence of plankton concentration on gametogenesis and spawning of the black lip pearl oyster Pinctada margaritifera in Ahe atoll lagoon (Tuamotu Archipelago, French polynesia).

    PubMed

    Fournier, Jonathan; Levesque, Emmanuelle; Pouvreau, Stephane; Le Pennec, Marcel; Le Moullac, Gilles

    2012-01-01

    Pearl culture industry represents one of the dominant business sector of French Polynesia. However, it still entirely relies on unpredictable spat collection success. Our aim was to assess the influence of natural plankton concentration fluctuations on maturation and spawning of the black lip pearl oyster Pinctada margaritifera, during a 4 months survey conducted in Ahe atoll lagoon. Plankton concentration was assessed by chlorophyll a extraction and by microscope counts while gonadic index, gonado-visceral dry weights and histology were used to measure pearl oysters reproduction activity. We found that (i) plankton concentration fluctuations were mainly related to wind regime, (ii) gametogenesis rate was mainly related to plankton concentration, (iii) spawning occurred when maximal gonad storage was reached, (iv) plankton concentration was the main spawning synchronizing factor. These results contribute explaining P. margaritifera spat collection variability in French Polynesian atoll lagoon.

  18. Ocean-lagoon water and plankton exchanges in a semi-closed pearl farming atoll lagoon (Ahe, Tuamotu archipelago, French Polynesia)

    NASA Astrophysics Data System (ADS)

    Pagano, M.; Rodier, M.; Guillaumot, C.; Thomas, Y.; Henry, K.; Andréfouët, S.

    2017-05-01

    In atoll lagoons, plankton richness is highly dependent on water exchange with the ocean through the atoll rim. However, the dynamics of the physical and biological fluxes at the lagoon-ocean interface remain poorly characterized. Here, we studied the combined effects of lagoon-ocean water exchanges and local environmental conditions on the phyto- and zooplankton abundance and community structure across the atoll lagoon rim of Ahe (Tuamotu Archipelago, French Polynesia). Plankton and environmental variables were monitored in May 2013 (i) at several stations inside and outside the lagoon and (ii) during time-series corresponding to ebb-flood tidal cycles in the two types of channels connecting the lagoon to the ocean: at the passage (300 m long and about 11 m deep) and in hoa (i.e reef-flat less than 50 cm depth). Our results highlight tidally-driven selective plankton exchanges between the lagoon and external ocean. Phytoplankton (chlorophyll-a) and zooplankton biomass were respectively 4 times and 7 times higher in the lagoon than at stations outside the atoll lagoon. Copepoda was the dominant zooplankton group at the oceanic station (>75% abundance) whereas meroplankton (with bivalve larvae most common) was dominant at the lagoon stations (54%), in the passage (55-82%) and in hoa (>80%). These differences between sites suggest a loss of bivalve larvae through export to the ocean and retention and/or increased production of copepods in the lagoon. The daily export of bivalve larvae represents a low percentage of the lagoon stock, in agreement with previously published larval dispersal numerical models. The retention of copepods could constitute a significant input of nutrients and organic matter (through excretion, feces release, decomposition, and remineralization) into the lagoon.

  19. The nature of the island and banana states in atoll sources and a unified model for low-mass X-ray binaries

    NASA Astrophysics Data System (ADS)

    Church, M. J.; Gibiec, A.; Bałucińska-Church, M.

    2014-03-01

    We propose an explanation of the island and banana states and the relation between atoll and Z-track sources, constituting a unified model for low-mass X-ray binaries (LMXB). We find a dramatic transition at a luminosity of 1-2 × 1037 erg s-1 above which the high-energy cut-off ECO of the Comptonized emission in all sources is low at a few keV. There is thermal equilibrium between the neutron star at ˜2 keV and the Comptonizing accretion disc corona (ADC) causing the low ECO in the banana state of atolls and all states of the Z-track sources. Below this luminosity, ECO increases towards 100 keV causing the hardness of the island state. Thermal equilibrium is lost, the ADC becoming much hotter than the neutron star via an additional coronal heating mechanism. This suggests a unified model of LMXB: the banana state is a basic state with the mass accretion rate dot{M} increasing, corresponding to the normal branch of Z-track sources. The island state has high ADC temperature, this state not existing in the Z-sources with luminosities much greater than the critical value. The Z-track sources have an additional flaring branch consistent with unstable nuclear burning on the neutron star at high dot{M}. This burning regime does not exist at low dot{M} so this branch is not seen in atolls (except GX atolls). The horizontal branch in Z-track sources has a strong increase in radiation pressure disrupting the inner disc and launching relativistic jets.

  20. Technical Basis Document: A Statistical Basis for Interpreting Urinary Excretion of Plutonium Based on Accelerator Mass Spectrometry (AMS) for Selected Atoll Populations in the Marshall Islands

    SciTech Connect

    Bogen, K; Hamilton, T F; Brown, T A; Martinelli, R E; Marchetti, A A; Kehl, S R; Langston, R G

    2007-05-01

    We have developed refined statistical and modeling techniques to assess low-level uptake and urinary excretion of plutonium from different population group in the northern Marshall Islands. Urinary excretion rates of plutonium from the resident population on Enewetak Atoll and from resettlement workers living on Rongelap Atoll range from <1 to 8 {micro}Bq per day and are well below action levels established under the latest Department regulation 10 CFR 835 in the United States for in vitro bioassay monitoring of {sup 239}Pu. However, our statistical analyses show that urinary excretion of plutonium-239 ({sup 239}Pu) from both cohort groups is significantly positively associated with volunteer age, especially for the resident population living on Enewetak Atoll. Urinary excretion of {sup 239}Pu from the Enewetak cohort was also found to be positively associated with estimates of cumulative exposure to worldwide fallout. Consequently, the age-related trends in urinary excretion of plutonium from Marshallese populations can be described by either a long-term component from residual systemic burdens acquired from previous exposures to worldwide fallout or a prompt (and eventual long-term) component acquired from low-level systemic intakes of plutonium associated with resettlement of the northern Marshall Islands, or some combination of both.

  1. Sr Isotopic Variation in Shallow Water Carbonate Sequences: Stratigraphic, Chronostratigraphic, and Eustatic Implications of the Record at Enewetak Atoll

    NASA Astrophysics Data System (ADS)

    Quinn, Terrence M.; Lohmann, K. C.; Halliday, A. N.

    1991-06-01

    Sr isotope data from two boreholes within the lagoon at Enewetak Atoll have been used to evaluate the use of such data to correlate, date, and monitor sea level change in shallow water carbonate sequences. Correlative stratigraphic intervals of relatively invariant δ87Sr, separated by abrupt transitions to lower δ87Sr with increasing depth, are recognized in both boreholes. Conversion of δ87Sr values to age via calibration with the seawater δ87Sr trend with age indicates that correlative and synchronous deposition of atoll sediments occurred at ˜ 0.4, 1.2, and 2.1 Ma. In contrast, a ˜5 m.y. hiatus is recognized in one borehole but not the other. Sr isotope stratigraphy (SIS) is a powerful stratigraphic and chronostratigraphic tool in shallow water carbonate sequences only when significant secular variation of δ87Sr occurs and retention of depositional δ87Sr values is demonstrated. The latter is best demonstrated when δ87Sr data, are integrated with δ18O, δ13C, Sr content data and petrographic observations. Several diagenetically altered intervals have greater δ87Sr values, low δ13C values, and low Sr/Ca ratios relative to adjacent intervals, a combination that is consistent with open-system meteoric diagenesis. Calcite cements from these intervals have early Pleistocene (˜1.2 Ma) δ87Sr values despite their occurrence well within the late Pliocene (˜2.1 Ma) sequence. Thus local sedimentological and diagenetic processes have produced intralagoon variability in the SIS of the two boreholes, complicating subsurface stratigraphic correlations. The occurrence of anomalously young calcite cement relative to adjacent limestone is a direct response of the interaction of sea level change and meteoric phreatic diagenesis whereby overlying metastable carbonates, with greater δ87Sr values, are dissolved during periods of atoll emergence and sea level lowstand liberating Sr and soil-gas CO2 to the pore fluid, which is then incorporated into downflow meteoric

  2. 29 CFR 776.7 - Geographical scope of coverage.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...; Guam; Wake Island; Enewetok Atoll; Kwajalein Atoll; Johnston Island; and the Canal Zone are dealt with... within the District of Columbia; Puerto Rico; the Virgin Islands; Outer Continental Shelf lands defined... the Act's coverage by this law or for work performed prior to Nov. 29, 1957, on Guam, Wake Island,...

  3. 29 CFR 5.15 - Limitations, variations, tolerances, and exemptions under the Contract Work Hours and Safety...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...; Puerto Rico; the Virgin Islands; Outer Continental Shelf lands defined in the Outer Continental Shelf Lands Act (ch. 345, 67 Stat. 462); American Samoa; Guam; Wake Island; Eniwetok Atoll; Kwajalein Atoll; and Johnston Island. (2) Agreements entered into by or on behalf of the Commodity Credit...

  4. 29 CFR 5.15 - Limitations, variations, tolerances, and exemptions under the Contract Work Hours and Safety...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...; Puerto Rico; the Virgin Islands; Outer Continental Shelf lands defined in the Outer Continental Shelf Lands Act (ch. 345, 67 Stat. 462); American Samoa; Guam; Wake Island; Eniwetok Atoll; Kwajalein Atoll; and Johnston Island. (2) Agreements entered into by or on behalf of the Commodity Credit...

  5. 29 CFR 5.15 - Limitations, variations, tolerances, and exemptions under the Contract Work Hours and Safety...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...; Puerto Rico; the Virgin Islands; Outer Continental Shelf lands defined in the Outer Continental Shelf Lands Act (ch. 345, 67 Stat. 462); American Samoa; Guam; Wake Island; Eniwetok Atoll; Kwajalein Atoll; and Johnston Island. (2) Agreements entered into by or on behalf of the Commodity Credit...

  6. 29 CFR 776.7 - Geographical scope of coverage.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...; Guam; Wake Island; Enewetok Atoll; Kwajalein Atoll; Johnston Island; and the Canal Zone are dealt with... within the District of Columbia; Puerto Rico; the Virgin Islands; Outer Continental Shelf lands defined... the Act's coverage by this law or for work performed prior to Nov. 29, 1957, on Guam, Wake Island,...

  7. 50 CFR 665.599 - Area restrictions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... the shoreline and the 50 fm (91.5 m) curve around Johnston Atoll, Palmyra Atoll, and Wake Island as... ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES IN THE WESTERN PACIFIC Pacific Remote Island Area... Islands, and Kingman Reef; as depicted on National Ocean Survey Chart Numbers 83116 and 83153. (b)...

  8. 50 CFR 665.599 - Area restrictions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES IN THE WESTERN PACIFIC Pacific Remote Island Area Fisheries... MPAs. The following U.S. EEZ waters in the Western Pacific Region are low-use MPAs: All waters between the shoreline and the 50 fm (91.5 m) curve around Johnston Atoll, Palmyra Atoll, and Wake Island...

  9. 50 CFR 665.599 - Area restrictions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES IN THE WESTERN PACIFIC Pacific Remote Island Area... MPAs. The following U.S. EEZ waters in the Western Pacific Region are low-use MPAs: All waters between the shoreline and the 50 fm (91.5 m) curve around Johnston Atoll, Palmyra Atoll, and Wake Island...

  10. Deepwater carbonate deposition in response to re-flooding of carbonate bank and atoll-tops at glacial terminations

    NASA Astrophysics Data System (ADS)

    Jorry, Stéphan J.; Droxler, André W.; Francis, Jason M.

    2010-08-01

    The late Quaternary has experienced large glacial/interglacial climatic variations and related 10's to 100 meters high-amplitude sea level fluctuations at Milankovich frequencies from 10's to 100 kyr during which carbonate platform tops have been exposed and re-flooded in many occasions. This study focuses on the accumulation of calci-turbidites, the aragonite onset/sharp increase in fine sediments and their timing in deep basins adjacent to carbonate platforms. A particular emphasis is developed on the occurrence of the first gravity flow event and aragonite onset/sharp increase and their linkage to the initial re-flooding of the platform tops during deglaciations. Three basins adjacent to isolated platforms in the Bahamas, the Northern Nicaragua Rise, and the Gulf of Papua, were selected to represent pure carbonate versus mixed systems, in quiescent versus tectonically active settings, and various carbonate bank top morphologies, ranging from atoll to relatively deeply and narrowly flooded flat top banks. In spite of these differences, each record illustrates a clear relationship between the timing of platform top re-flooding and initiation of significant carbonate export by gravity flows and low-density plumes into the surrounding basins. The concept of "re-flooding window" is introduced to characterize the prolific period of time during which bank and atoll-tops are flooded enough to produce large export of bank-derived aragonite and of calci-turbidites in adjacent basins. According to our datasets, the main re-flooding windows have occurred mainly on the last part of the sea level rise at each glacial termination (T), those periods being marked by some of the highest rates of sea level rise. The analysis of a long-piston core from the earthquakes-prone Walton Basin (Northern Nicaragua Rise) demonstrates that sea level, not seismic activities, played a major role as trigger mechanism for the initiation of gravity flows since the last four glacial

  11. Hydrogeology and ground-water resources of Pingelap Island, Pingelap Atoll, State of Pohnpei, Federated States of Micronesia

    USGS Publications Warehouse

    Anthony, S.S.

    1996-01-01

    The lens of fresh ground water on Pingelap Island, Pingelap Atoll contains about 384 million gallons of potable water. Recharge to the freshwater lens is estimated to be 230,000 gallons per day on the basis of an average annual rainfall of 160 inches. The long-term average sustainable yield is estimated to be about 69,000 gallons per day. The estimated demand for water is about 50,000 gallons per day. Shallow-vertical-tube wells or horizontal-infiltration wells could be used to develop the freshwater lens. The effect of development on the lens can be determined by monitoring the chloride concentration of water from a network of shallow-water-table wells and deep driven wells. The ground-water resource on Pingelap can be used in conjunction with individual rainwater-catchment systems: rainwater can be used for drinking and cooking, and ground water can be used for sanitary uses. When rainwater-catchment systems fail during extended dry periods, ground water would be available to meet the total demand.

  12. Long-Term Reduction in 137Cs Concentration in Food Crops on Coral Atolls Resulting from Potassium Treatment

    SciTech Connect

    Robison, W L; Stone, E L; Hamilton, T F; Conrado, C L

    2004-04-14

    Bikini Island was contaminated March 1, 1954 by the Bravo detonation (U.S nuclear test series, Castle) at Bikini Atoll. About 90% of the estimated dose from nuclear fallout to potential island residents is from cesium-137 ({sup 137}Cs) transferred from soil to plants that are consumed by residents. Thus, radioecology research efforts have been focused on removing {sup 137}Cs from soil and/or reducing its uptake into vegetation. Most effective was addition of potassium (K) to soil that reduces {sup 137}Cs concentration in fruits to 3-5% of pretreatment concentrations. Initial observations indicated this low concentration continued for some time after K was last applied. Long-term studies were designed to evaluate this persistence in more detail because it is very important to provide assurance to returning populations that {sup 137}Cs concentrations in food (and, therefore, radiation dose) will remain low for extended periods, even if K is not applied annually or biennially. Potassium applied at 300, 660, 1260, and 2070 kg ha{sup -1} lead to a {sup 137}Cs concentration in drinking coconut meat that is 34, 22, 10, and about 4% of original concentration, respectively. Concentration of {sup 137}Cs remains low 8 to 10 y after K is last applied. An explanation for this unexpected result is discussed.

  13. Long-Term Reduction in 137Cs Concentration in Food Crops on Coral Atolls Resulting from Potassium Treatment

    SciTech Connect

    Robison, W; Stone, E; Hamilton, T; Conrado, C

    2005-04-08

    Bikini Island was contaminated March 1, 1954 by the Bravo detonation (U.S nuclear test series, Castle) at Bikini Atoll. About 90% of the estimated dose from nuclear fallout to potential island residents is from cesium-137 ({sup 137}Cs) transferred from soil to plants that are consumed by residents. Thus, radioecology research efforts have been focused on removing {sup 137}Cs from soil and/or reducing its uptake into vegetation. Most effective was addition of potassium (K) to soil that reduces {sup 137}Cs concentration in fruits to 3-5% of pretreatment concentrations. Initial observations indicated this low concentration continued for some time after K was last applied. Long-term studies were designed to evaluate this persistence in more detail because it is very important to provide assurance to returning populations that {sup 137}Cs concentrations in food (and, therefore, radiation dose) will remain low for extended periods, even if K is not applied annually or biennially. Potassium applied at 300, 660, 1260, and 1970 kg ha{sup -1} lead to a {sup 137}Cs concentration in drinking coconut meat that is 34, 22, 10, and about 4 % of original concentration, respectively. Concentration of {sup 137}Cs remains low 8 to 10 y after K is last applied. An explanation for this unexpected result is discussed.

  14. Bivalve larvae transport and connectivity within the Ahe atoll lagoon (Tuamotu Archipelago), with application to pearl oyster aquaculture management.

    PubMed

    Thomas, Y; Le Gendre, R; Garen, P; Dumas, F; Andréfouët, S

    2012-01-01

    Patterns of bivalve larvae dispersal in the deep Ahe atoll lagoon was studied by using a numerical 3D transport model (MARS3D) coupled with a vertical swimming sub-model, forced mainly by tide and wind-induced currents. The simulations were validated against observations of larval dispersal monitored several days throughout the lagoon. Connectivity matrices describing larval exchanges inside the lagoon were inferred. Larvae displayed a significant dispersal capacity at the lagoon scale, especially with dominant eastern winds. With southeastern winds, larvae mostly remained in their origin sector. The total export rate of the larvae, toward the ocean through the pass and shallow lagoon borders, was independent of the wind conditions, with 1% of the total concentration exported per day. However, the tide-driven currents efficiently flushed larvae in sectors close to the pass. Connectivity matrices suggest that the south and west sectors were more suitable for spat collecting and that central sectors would be efficient sanctuaries if genitors were accumulated.

  15. Phylogenetic Analysis of a Microbialite-Forming Microbial Mat from a Hypersaline Lake of the Kiritimati Atoll, Central Pacific

    PubMed Central

    Schneider, Dominik; Arp, Gernot; Reimer, Andreas; Reitner, Joachim; Daniel, Rolf

    2013-01-01

    On the Kiritimati atoll, several lakes exhibit microbial mat-formation under different hydrochemical conditions. Some of these lakes trigger microbialite formation such as Lake 21, which is an evaporitic, hypersaline lake (salinity of approximately 170‰). Lake 21 is completely covered with a thick multilayered microbial mat. This mat is associated with the formation of decimeter-thick highly porous microbialites, which are composed of aragonite and gypsum crystals. We assessed the bacterial and archaeal community composition and its alteration along the vertical stratification by large-scale analysis of 16S rRNA gene sequences of the nine different mat layers. The surface layers are dominated by aerobic, phototrophic, and halotolerant microbes. The bacterial community of these layers harbored Cyanobacteria (Halothece cluster), which were accompanied with known phototrophic members of the Bacteroidetes and Alphaproteobacteria. In deeper anaerobic layers more diverse communities than in the upper layers were present. The deeper layers were dominated by Spirochaetes, sulfate-reducing bacteria (Deltaproteobacteria), Chloroflexi (Anaerolineae and Caldilineae), purple non-sulfur bacteria (Alphaproteobacteria), purple sulfur bacteria (Chromatiales), anaerobic Bacteroidetes (Marinilabiacae), Nitrospirae (OPB95), Planctomycetes and several candidate divisions. The archaeal community, including numerous uncultured taxonomic lineages, generally changed from Euryarchaeota (mainly Halobacteria and Thermoplasmata) to uncultured members of the Thaumarchaeota (mainly Marine Benthic Group B) with increasing depth. PMID:23762495

  16. Long-term reduction in (137)Cs concentration in food crops on coral atolls resulting from potassium treatment.

    PubMed

    Robison, William L; Stone, E L; Hamilton, T F; Conrado, C L

    2006-01-01

    Bikini Island was contaminated on March 1, 1954 by the Bravo detonation (U.S. nuclear test series, Castle) at Bikini Atoll. About 90% of the estimated dose from nuclear fallout to potential island residents is from cesium-137 ((137)Cs) transferred from soil to plants that are consumed by residents. Thus, radioecology research efforts have been focused on removing (137)Cs from soil and/or reducing its uptake into vegetation. Most effective was addition of potassium (K) to soil that reduces (137)Cs concentration in fruits to 3-5% of pretreatment concentrations. Initial observations indicated this low concentration continued for some time after K was last applied. Long-term studies were designed to evaluate this persistence in more detail because it is very important to provide assurance to returning populations that (137)Cs concentrations in food (and, therefore, radiation dose) will remain low for extended periods, even if K is not applied annually or biennially. Potassium applied at 300, 660, 1260, and 2070 kg ha(-1) lead to a (137)Cs concentration in drinking-coconut meat that is 34, 22, 10, and about 4% of original concentration, respectively. Concentration of (137)Cs remains low 8-10 y after K is last applied. An explanation for this unexpected result is discussed.

  17. Distribution, burrowing, and growth rates of the clam Tridacna crocea on interior reef flats : Formation of structures resembling micro atolls.

    PubMed

    Hamner, W M; Jones, M S

    1976-09-01

    Larvae of the burrowing clam Tridacna crocea (Tridacnidae) settle preferentially on top of detached coral heads lying on the surface of the interior reef flat in the Great Barrier Reef province. This species burrows as it grows, eroding the central top surfaces of coral boulders, producing structures that superficially resemble micro-atolls. Storm surges roll these coral heads onto the now flattened surface, killing the live population of clams, and exposing the fresh underside for unimpeded larval settlement. As these clams grow and burrow into the substratum, the coral head becomes progressively flattened and finally breaks apart. Field observations and growthring data documented growth rate; growth rates plus burrow volumes were converted to annual sediment production. At average population densities approximately 140 gm/m(2)/yr of coral are eroded. Concomitant with erosion is a calcium carbonate increase in the shell of these clams amounting to 60gm/m(2)/yr. Assuming a stable population structure, with annual mortality equal to annual estimated growth, total sediment production is 200 gm/m(2)/yr. Clams are usually aggregated at higher densities, however, with numbers regularly exceeding 100 clams/m(2). Consequently maximum sediment production rate locally is often 4,500 gm/m(2)/yr.

  18. Physical, chemical, and microbiological characteristics of microbial mats (kopara) in the South Pacific atolls of French Polynesia.

    PubMed

    Che, L M; Andréfouët, S; Bothorel, V; Guezennec, M; Rougeaux, H; Guezennec, J; Deslandes, E; Trichet, J; Matheron, R; Le Campion, T; Payri, C; Caumette, P

    2001-11-01

    Microbial mats that develop in shallow brackish and hyposaline ponds in the rims of two French polynesian atolls (Rangiroa and Tetiaroa) were intensively investigated during the past three years. Comparative assessment of these mats (called kopara in polynesian language) showed remarkable similarities in their composition and structure. Due to the lack of iron, the color of the cyanobacterial pigments produced remained visible through the entire depth of the mats (20-40 cm depth), with alternate green, purple, and pink layers. Profiles of oxygen, sulfide, pH, and redox showed the anoxia of all mats from a depth of 2-3 mm. Analyses of bacterial pigments and bacterial lipids showed that all mats consisted of stratified layers of cyanobacteria (mainly Phormidium, Schizothrix, Scytonema) and purple and green phototrophic bacteria. The purple and green phototrophic bacteria cohabit with sulfate reducers (Desulfovibrio and Desulfobacter) and other heterotrophic bacteria. The microscopic bacterial determination emphasized the influence of salinity on the bacterial diversity, with higher diversity at low salinity, mainly for purple nonsulfur bacteria. Analyses of organic material and of exopolymers were also undertaken. Difference and similarities between mats from geomorphological, microbiological, and chemical points of view are discussed to provide multicriteria of classification of mats.

  19. The application of PIT tags to measure transport of detrital coral fragments on a fringing reef: Majuro Atoll, Marshall Islands

    NASA Astrophysics Data System (ADS)

    Ford, Murray R.

    2014-06-01

    Passive integrated transponder (PIT) tags are a radio-frequency identification device widely used as a machine-readable identification tool in fisheries research. PIT tags have also been employed, to a lesser extent, to track the movement of gravel-sized clasts within fluvial and coastal systems. In this study, PIT tags were inserted into detrital coral fragments and used to establish source-sink transport pathways on a fringing reef on Majuro Atoll in the Marshall Islands. Results suggest the transport of gravel-sized material on the inter-tidal reef flat is exclusively across-reef towards the lagoon. Considerable variation in the distance travelled by fragments was observed. Fragments were largely intact and visually recognisable after almost 5 months on the reef flat. However, the branches of some recovered fragments had broken off and corallite abrasion was observed in recovered fragments. This study indicates that PIT tags are an inexpensive and powerful new addition to the suite of sediment transport and taphonomic tools for researchers working within coral reef systems.

  20. Phylogenetic analysis of a microbialite-forming microbial mat from a hypersaline lake of the Kiritimati atoll, Central Pacific.

    PubMed

    Schneider, Dominik; Arp, Gernot; Reimer, Andreas; Reitner, Joachim; Daniel, Rolf

    2013-01-01

    On the Kiritimati atoll, several lakes exhibit microbial mat-formation under different hydrochemical conditions. Some of these lakes trigger microbialite formation such as Lake 21, which is an evaporitic, hypersaline lake (salinity of approximately 170‰). Lake 21 is completely covered with a thick multilayered microbial mat. This mat is associated with the formation of decimeter-thick highly porous microbialites, which are composed of aragonite and gypsum crystals. We assessed the bacterial and archaeal community composition and its alteration along the vertical stratification by large-scale analysis of 16S rRNA gene sequences of the nine different mat layers. The surface layers are dominated by aerobic, phototrophic, and halotolerant microbes. The bacterial community of these layers harbored Cyanobacteria (Halothece cluster), which were accompanied with known phototrophic members of the Bacteroidetes and Alphaproteobacteria. In deeper anaerobic layers more diverse communities than in the upper layers were present. The deeper layers were dominated by Spirochaetes, sulfate-reducing bacteria (Deltaproteobacteria), Chloroflexi (Anaerolineae and Caldilineae), purple non-sulfur bacteria (Alphaproteobacteria), purple sulfur bacteria (Chromatiales), anaerobic Bacteroidetes (Marinilabiacae), Nitrospirae (OPB95), Planctomycetes and several candidate divisions. The archaeal community, including numerous uncultured taxonomic lineages, generally changed from Euryarchaeota (mainly Halobacteria and Thermoplasmata) to uncultured members of the Thaumarchaeota (mainly Marine Benthic Group B) with increasing depth.