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Western Pacific Ocean (western + pacific_ocean)
Selected AbstractsThe migration route and behaviour of Eastern Curlews Numenius madagascariensisIBIS, Issue 3 2002Peter V. Driscoll Eastern Curlews Numenius madagascariensis were satellite-tracked onto breeding grounds in north-eastern Russia from south-eastern Queensland over a distance of 12 000 km. They made initial non-stop, long distance flights across the Western Pacific Ocean towards the coastlines of China and Korea followed by shorter flights, over a period of more than a month. The return journey involved a major flight-leg as well, south from the Yellow Sea region. Many birds attempted to migrate but returned to the non-breeding grounds over periods of up to several months. Islands of the Western Pacific region, the southern coastline of New Guinea and north-eastern coastline of Australia are important, particularly for birds that stop migrating. Eastern Curlews that stopped migrating generally survived, which suggests that the species has adapted to deal with adverse conditions en route and/or a physical inability to complete the migration. Such a capacity is perhaps characteristic of a large wader with low annual mortality. [source] Variability and trends in the directional wave climate of the Southern HemisphereINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 4 2010Mark A. Hemer Abstract The effect of interannual climate variability and change on the historic, directional wave climate of the Southern Hemisphere is presented. Owing to a lack of in situ wave observations, wave climate in the Southern Hemisphere is determined from satellite altimetry and global ocean wave models. Altimeter data span the period 1985 to present, with the exception of a 2-year gap in 1989,1991. Interannual variability and trends in the significant wave height are determined from the satellite altimeter record (1991 to present), and the dominant modes of variability are identified using an empirical orthogonal function (EOF) analysis. Significant wave heights in the Southern Ocean are observed to show a strong positive correlation with the Southern Annular Mode (SAM), particularly during Austral autumn and winter months. Correlation between altimeter derived significant wave heights and the Southern Oscillation Index is observed in the Pacific basin, which is consistent with several previous studies. Variability and trends of the directional wave climate are determined using the ERA-40 Waves Re-analysis for the period 1980,2001. Significant wave height, mean wave period and mean wave direction data are used to describe the climate of the wave energy flux vector. An EOF analysis of the wave energy flux vector is carried out to determine the dominant modes of variability of the directional seasonal wave energy flux climate. The dominant mode of variability during autumn and winter months is strongly correlated to the SAM. There is an anti-clockwise rotation of wave direction with the southward intensification of the Southern Ocean storm belt associated with the SAM. Clockwise rotation of flux vectors is observed in the Western Pacific Ocean during El-Nino events. Directional variability of the wave energy flux in the Western Pacific Ocean has previously been shown to be of importance to sand transport along the south-eastern Australian margin, and the New Zealand region. The directional variability of the wave energy flux of the Southern Ocean associated with the SAM is expected to be of importance to the wave-driven currents responsible for the transport of sand along coastal margins in the Southern Hemisphere, in particular those on the Southern and Western coastal margins of the Australian continent. Copyright © 2009 Royal Meteorological Society [source] Impacts of tropical cyclones on the regional climate: An East Asian summer monsoon caseATMOSPHERIC SCIENCE LETTERS, Issue 4 2007Zhong Zhong Abstract The contribution of tropical cyclones (TCs) over the Western Pacific Ocean (WPO) and China to the formation of the regional climate over East Asia is investigated by the use of a regional climate model. Our results show that the regional climate is significantly affected by the frequency of TC activity in terms of weakening the Western Pacific subtropical high when TCs are over the WPO and interrupting the summer monsoon when TCs make landfall over China. If there were no TCs, the atmosphere over southeast and northeast China would become drier, while that over southwest and north China would become wetter. Copyright © 2007 Royal Meteorological Society [source] A mitochondrial phylogeography of Brachidontes variabilis (Bivalvia: Mytilidae) reveals three cryptic speciesJOURNAL OF ZOOLOGICAL SYSTEMATICS AND EVOLUTIONARY RESEARCH, Issue 4 2007M. Sirna Terranova Abstract This study examined genetic variation across the range of Brachidontes variabilis to produce a molecular phylogeography. Neighbour joining (NJ), minimum evolution (ME) and maximum parsimony (MP) trees based on partial mitochondrial DNA sequences of 16S-rDNA and cytochrome oxidase (COI) genes revealed three monophyletic clades: (1) Brachidontes pharaonis s.l. from the Mediterranean Sea and the Red Sea; (2) B. variabilis from the Indian Ocean; (3) B. variabilis from the western Pacific Ocean. Although the three clades have never been differentiated by malacologists employing conventional morphological keys, they should be ascribed to the taxonomic rank of species. The nucleotide divergences between Brachidontes lineages (between 10.3% and 23.2%) were substantially higher than the divergence between congeneric Mytilus species (2.3,6.7%) and corresponded to interspecific divergences found in other bivalvia, indicating that they should be considered three different species. Analysis of the 16S-rDNA sequences revealed heteroplasmy, indicating dual uniparental inheritance (DUI) of mtDNA in the species of Brachidontes collected in the Indian Ocean, but not in the species in the Pacific nor in the species in the Red Sea and the Mediterranean Sea. When we employed the conventional estimate of the rate of mitochondrial sequence divergence (2% per million years), the divergence times for the three monophyletic lineages were 6,11 Myr for the Indian Ocean and Pacific Ocean Brachidontes sp. and 6.5,9 Myr for the Red Sea and Indian Ocean Brachidontes sp. Thus, these species diverged from one another during the Miocene (23.8,5.3 Myr). We infer that a common ancestor of the three Brachidontes species probably had an Indo-Pacific distribution and that vicariance events, linked to Pleistocene glaciations first and then to the opening of the Red Sea, produced three monophyletic lineages. Riassunto Lo studio filogeografico è stato condotto su tutto l'areale di Brachidontes variabilis (Krauss, 1848) attraverso l'analisi di sequenze mitocondriali (16S-rDNA e COI) che hanno separato i campioni in tre cladi monofiletici. Diversi algoritmi (NJ, ME e MP) hanno elaborato alberi con la stessa topologia, in cui è possibile riconoscere: (1) Brachidontes pharaonis s.l. dell'area Mar Mediterraneo , Mar Rosso; (2) Brachidontes variabilis dell' Oceano Indiano; (3) Brachidontesvariabilis dell'Oceano Pacifico. Il loro grado di divergenza è sufficientemente alto da potere ascrivere al rango di specie i singoli cladi, nonostante non siano stati ancora individuati i caratteri tassonomici distintivi, a causa della grande variazione morfologica. La divergenza nucleotidica tra le tre linee di Brachidontes era compresa tra 10.3% e 23.2%, in un range di valori superiori a quelli trovati nel confronto tra specie congeneriche di Mytilus sp (2.3,6.7%). Utilizzando il tasso evolutivo, che convenzionalmente viene applicato ai valori di divergenza genetica di geni mitocondriali (2% per milioni di anni), si sono ricavati tempi di divergenza corrispondenti a 6,11 milioni di anni tra Oceano Indiano e Pacifico, e a 6.5,9 milioni di anni tra Mar Rosso e Oceano Indiano. Le tre linee evolutive sembrano essersi separate durante il Miocene. Probabilmente un comune antenato con distribuzione Indo-Pacifica può essere andato incontro a processi di vicarianza e/o di dispersione legati alle glaciazioni pleistoceniche prima e all'apertura del Mar Rosso dopo. [source] Sebdenia cerebriformis sp. nov. (Sebdeniaceae, Sebdeniales) from the south and western Pacific OceanPHYCOLOGICAL RESEARCH, Issue 1 2008Antoine D.R. N'Yeurt SUMMARY A new species of red alga, Sebdenia cerebriformis N'Yeurt et Payri sp. nov. (Sebdeniaceae, Sebdeniales), is described from various localities in the south and western Pacific including Fiji, New Caledonia, the Solomon Islands, Vanuatu, and Indonesia (Java Sea). The new species is characterized by a ruffled thallus with multiple perennial stipitate holdfasts, large conspicuous inner cortical stellate cells, and a lax filamentous medulla. [source] Effects of Season, Rainfall, and Hydrogeomorphic Setting on Mangrove Tree Growth in MicronesiaBIOTROPICA, Issue 2 2007Ken W. Krauss ABSTRACT Seasonal patterns of tree growth are often related to rainfall, temperature, and relative moisture regimes. We asked whether diameter growth of mangrove trees in Micronesia, where seasonal changes are minimal, is continuous throughout a year or conforms to an annual cycle. We installed dendrometer bands on Sonneratia alba and Bruguiera gymnorrhiza trees growing naturally within mangrove swamps on the islands of Kosrae, Federated States of Micronesia (FSM), Pohnpei, FSM, and Butaritari, Republic of Kiribati, in the eastern Caroline Islands of the western Pacific Ocean. Trees were remeasured monthly or quarterly for as long as 6 yr. Annual mean individual tree basal area increments ranged from 7.0 to 79.6 cm2/yr for all S. alba trees and from 4.8 to 27.4 cm2/yr for all B. gymnorrhiza trees from Micronesian high islands. Diameter increment for S. alba on Butaritari Atoll was lower at 7.8 cm2/yr for the one year measured. Growth rates differed significantly by hydrogeomorphic zone. Riverine and interior zones maintained up to seven times the annual diameter growth rate of fringe forests, though not on Pohnpei, where basal area increments for both S. alba and B. gymnorrhiza were approximately 1.5 times greater in the fringe zone than in the interior zone. Time-series modeling indicated that there were no consistent and statistically significant annual diameter growth patterns. Although rainfall has some seasonality in some years on Kosrae and Pohnpei and overall growth of mangroves was sometimes related positively to quarterly rainfall depths, seasonal diameter growth patterns were not distinctive. A reduced chance of moisture-related stress in high-rainfall, wetland environments may serve to buffer growth of Micronesian mangroves from climatic extremes. [source] Interannual changes in sablefish (Anoplopoma fimbria) recruitment in relation to oceanographic conditions within the California Current SystemFISHERIES OCEANOGRAPHY, Issue 1 2006MICHAEL J. SCHIRRIPA Abstract Sablefish (Anoplopoma fimbria) supports substantial fisheries in both the eastern and western Pacific Oceans. Juvenile recruitment along the west coast of the continental United States has been highly variable over the past three decades. Using a generalized additive model, we demonstrate that physical oceanographic variables within the California Current System have significant effects on sablefish recruitment. Significant relationships were found between juvenile recruitment and northward Ekman transport, eastward Ekman transport, and sea level during key times and at key locations within the habitat of this species. The model explains nearly 70% of the variability in sablefish recruitment between the years 1974 and 2000. The predictive power of the model was demonstrated by refitting without the last 5 yr of data and subsequent prediction of those years. Bootstrap assessments of bias associated with parameter estimates and jackknife-after-bootstrap assessments of the influence of individual data on parameter estimates are presented and discussed. Using this model, it is possible to draw preliminary conclusions concerning year-class strength of cohorts not yet available to the survey gear as well as historic year-class strengths. We discuss changes in zooplankton abundance and shifts in species of copepods associated with fluctuations in the physical variables that appear to have a major influence on sablefish recruitment. [source] | |||||||||||||