Home About us Contact
|
Home About us Contact | ||
|
|
||
Pacific
Kinds of Pacific Terms modified by Pacific Selected AbstractsIDENTIFICATION AND ASSESSMENT OF DOMOIC ACID PRODUCTION IN OCEANIC PSEUDO-NITZSCHIA (BACILLARIOPHYCEAE) FROM IRON-LIMITED WATERS IN THE NORTHEAST SUBARCTIC PACIFIC,JOURNAL OF PHYCOLOGY, Issue 3 2008Adrian Marchetti We identified and investigated the potential toxicity of oceanic Pseudo-nitzschia species from Ocean Station Papa (OSP), located in a high-nitrate, low-chlorophyll (HNLC) region of the northeast (NE) subarctic Pacific Ocean. Despite their relatively low abundances in the indigenous phytoplankton assemblage, Pseudo-nitzschia species richness is high. The morphometric characteristics of five oceanic Pseudo-nitzschia isolates from at least four species are described using SEM and TEM. The species identified are Pseudo-nitzschia dolorosa Lundholm et Moestrup, P. granii Hasle, P. heimii Manguin, and P. cf. turgidula (Hust.) Hasle. Additional support for the taxonomic classifications based on frustule morphology is provided through the sequencing of the internal transcribed spacer 1 (ITS1) rDNA. Pseudo-nitzschia species identification was also assessed by the construction of ITS1 clone libraries and using automated ribosomal intergenic spacer analysis (ARISA) for environmental samples collected during the Subarctic Ecosystem Response to Iron Enrichment Study (SERIES), conducted in close proximity to OSP in July of 2002. Based on ITS1 sequences, the presence of P. granii, P. heimii, P. cf. turgidula, and at least five other putative, unidentified Pseudo-nitzschia ITS1 variants was confirmed within iron-enriched phytoplankton assemblages at OSP. None of the oceanic isolates produced detectable levels of particulate domoic acid (DA) when in prolonged stationary phase due to silicic acid starvation. The lack of detectable concentrations of DA suggests that either these strains produce very little or no toxin, or that the physiological conditions required to promote particulate DA production were not met and thus differ from their coastal, toxigenic congeners. [source] GEOGRAPHICAL VARIATION OF THE PARASITE, PHYLLOBOTHRIUM DELPHINI (CESTODA), IN BALL'S PORPOISE, PHOCOENOIDES DALLI, IN THE NORTHERN NORTH PACIFIC, BERING SEA, AND SEA OF OKHOTSKMARINE MAMMAL SCIENCE, Issue 2 2001William A. Walker Abstract Prevalence of the larval cestode, Phyllobothrium delphini, was estimated from 2,445 Dall's porpoise, Phocoenoides dalli, from the incidental take of the Japanese high seas salmon drift-net fishery in the northwestern North Pacific Ocean, Bering Sea, and a local hand harpoon fishery in the southern Sea of Okhotsk. Prevalence of P. delphini was 22.7% in the northwestern North Pacific Ocean and 1.4% in the Bering Sea. This parasite was not found in the southern Sea of Okhotsk. Geographical differences in the prevalence of P. delphini may be due, at least in part, to regional differences in abundance of elasmobranchs known to feed on marine mammals and suspected as hosts of the parasite. Estimated intensity of infection of individual porpoises by P. delphini was low (estimated mean intensity of 3.5 plerocercoids per animal). This is a low intensity of infection compared to other species of small cetaceans studied and may be due to both differences in regional abundance of elasmobranchs and the comparatively short life span of P. dalli. [source] CO-EVOLUTION OF THE ELECTRONICS INDUSTRY: POLICY INTERACTIONS ACROSS THE PACIFICPACIFIC ECONOMIC REVIEW, Issue 4 2007An-Chi Tung From the world distribution of the major IT producing and using firms, and the fabrication and trading network, the prominence of the Pacific Rim nexus stands out. The comparative advantages and trade gains of individual economies are decided by the impact of the institutional and policy matrix. In turn, their competing yet complementary relations give policy analysis a historical perspective. The policy performance interplay yields new insight into both how the world stands, and what the national policy should be, other things being given. [source] Conflict resolution education in the Asian PacificCONFLICT RESOLUTION QUARTERLY, Issue 1 2007Bruce E. Barnes Conflict Resolution Education (CRE) is taking hold in the Oceania-Island Pacific-East Asia and Southeast Asia region. This article highlights several promising programs from New Zealand-Aotearoa, Singapore, Hong Kong, Fiji, and Australia. Peer mediation programs range from the Cool Schools programs present in more than half of all the schools in New Zealand to newer programs in Singapore. Restorative justice programs are operating in New Zealand, Australia, and Hong Kong. International efforts in both CR and CRE by universities in the region are discussed, highlighting regional centers in South Australia (uniSA) and Queensland (ACPACS). Information is also given about the Asia Pacific Mediation Forum, which will be presenting its third regional conference in June 2008 in Malaysia. [source] Conservation Biology in the PacificCONSERVATION BIOLOGY, Issue 6 2004Harry F. Recher Editor, Pacific Conservation Biology No abstract is available for this article. [source] A COMPARISON OF MEXICAN MIGRANT REMITTANCES ACROSS U.S. REGIONSCONTEMPORARY ECONOMIC POLICY, Issue 3 2008STEPHEN T. FAIRCHILD Since 1990, the United States has experienced a geographic dispersion of Mexican migrants from traditional gateways to new regions. Using data from the Mexican Migration Project, we find significant differences in both the likelihood of remitting and the amount remitted by Mexican migrants across U.S. regions. Specifically, Mexican migrants living in U.S. regions that have experienced considerable increases in migrant populations since 1990 (the Northeast, Southeast, Mountain, and Midwest regions) remit at higher rates and in larger quantities than migrants living in more traditional migrant destinations (the Pacific and South Central regions), even after controlling for observed differences in migrant populations. (JEL F22, F32, J11, R23) [source] ,Best Practice' Options for the Legal Recognition of Customary TenureDEVELOPMENT AND CHANGE, Issue 3 2005Daniel Fitzpatrick Is there a ,best practice' model for the legal recognition of customary tenure? If not, is it possible to identify the circumstances in which a particular model would be most appropriate? This article considers these questions in the light of economic theories of property rights, particularly as illustrated by the World Bank's 2003 land policy report. While these theories have their flaws, the underlying concept of tenure security allows a typological framework for developing legal responses to customary tenure. In particular, this article suggests that the nature and degree of State legal intervention in a customary land system should be determined by reference to the nature and causes of any tenure insecurity. This hypothesis is discussed by reference to a wide variety of legal examples from Africa, Papua New Guinea and the South Pacific. The objective is not to suggest that law determines resource governance outcomes in pluralist normative environments, but to improve the quality of legal interventions in order to assist customary groups to negotiate better forms of tenure security and access to resources. [source] The Economic Partnership Agreements: Rationale, Misperceptions and Non-trade AspectsDEVELOPMENT POLICY REVIEW, Issue 5 2008Louise Curran The European Union and the African, Caribbean and Pacific (ACP) countries entered a new era in 2008. The Cotonou trade regime and the WTO waiver legitimising it have expired, and the long anticipated, and much debated, move to Economic Partnership Agreements (EPAs) has begun. This article explains the background and analyses the ,alternatives' to EPAs, in order to tackle common misperceptions. Moving on from what has been the focus of debates, namely, the reciprocal liberalisation required under WTO rules, it sheds some light on the non-goods trade aspects of EPAs which, while integral to economic policy, are inherently hard to quantify and often skimmed over in existing studies or addressed in ideological terms. [source] BIODIVERSITY RESEARCH: Genetic diversity in two introduced biofouling amphipods (Ampithoe valida & Jassa marmorata) along the Pacific North American coast: investigation into molecular identification and cryptic diversityDIVERSITY AND DISTRIBUTIONS, Issue 5 2010Erik M. Pilgrim Abstract Aim, We investigated patterns of genetic diversity among invasive populations of Ampithoe valida and Jassa marmorata from the Pacific North American coast to assess the accuracy of morphological identification and determine whether or not cryptic diversity and multiple introductions contribute to the contemporary distribution of these species in the region. Location, Native range: Atlantic North American coast; Invaded range: Pacific North American coast. Methods, We assessed indices of genetic diversity based on DNA sequence data from the mitochondrial cytochrome c oxidase subunit I (COI) gene, determined the distribution of COI haplotypes among populations in both the invasive and putative native ranges of A. valida and J. marmorata and reconstructed phylogenetic relationships among COI haplotypes using both maximum parsimony and Bayesian approaches. Results, Phylogenetic inference indicates that inaccurate species-level identifications by morphological criteria are common among Jassa specimens. In addition, our data reveal the presence of three well supported but previously unrecognized clades of A. valida among specimens in the north-eastern Pacific. Different species of Jassa and different genetic lineages of Ampithoe exhibit striking disparity in geographic distribution across the region as well as substantial differences in genetic diversity indices. Main conclusions, Molecular genetic methods greatly improve the accuracy and resolution of identifications for invasive benthic marine amphipods at the species level and below. Our data suggest that multiple cryptic introductions of Ampithoe have occurred in the north-eastern Pacific and highlight uncertainty regarding the origin and invasion histories of both Jassa and Ampithoe species. Additional morphological and genetic analyses are necessary to clarify the taxonomy and native biogeography of both amphipod genera. [source] Taxonomic diversity gradients through geological timeDIVERSITY AND DISTRIBUTIONS, Issue 4 2001J. Alistair Crame Abstract., There is evidence from the fossil record to suggest that latitudinal gradients in taxonomic diversity may be time-invariant features, although almost certainly not on the same scale as that seen at the present day. It is now apparent that both latitudinal and longitudinal gradients increased dramatically in strength through the Cenozoic era (i.e. the last 65 my) to become more pronounced today than at any time in the geological past. Present-day taxonomic diversity gradients, in both the marine and terrestrial realms, are underpinned by the tropical radiations of a comparatively small number of species-rich clades. Quite why these particular taxa proliferated through the Cenozoic is uncertain, but it could be that at least part of the explanation involves the phenomenon of evolutionary escalation. This is, in essence, a theory of biological diversification through evolutionary feedback mechanisms between predators and prey; first one develops an adaptive advantage, and then the other. However, there may also have been some form of extrinsic control on the process of tropical diversification, and this was most likely centred on the phenomenon of global climate change. This is especially so over the last 15 my Various Late Cenozoic (Neogene) vicariant events effectively partitioned the tropics into a series of high diversity centres, or foci. It has been suggested that, in the largest of these in the marine realm (the Indo-West Pacific or IWP centre), a critical patterns of islands acted as a template for rapid speciation during glacioeustatic sea level cycles. The same process occurred in the Atlantic, Caribbean and East Pacific (ACEP) centre, though on a lesser scale. Tropical terrestrial diversity may also have been promoted by rapid range expansions and contractions in concert with glacial cycles (a modified refugium hypothesis). We are beginning to appreciate that an integrated sequence of Neogene tectonic and climatic events greatly influenced the formation of contemporary taxonomic diversity patterns. [source] Species richness of marine Bryozoa in the continental shelf and slope off Argentina (south-west Atlantic)DIVERSITY AND DISTRIBUTIONS, Issue 1 2000Juan López Gappa Abstract., A total of 246 marine bryozoan species was recorded within an area of the south-west Atlantic between 35° and 56°S, and between the coast of Argentina and 50°W. The distribution pattern of benthic stations surveyed during the most important cruises in the area shows that the sampling effort has been biased towards southern shelf areas off Santa Cruz and Tierra del Fuego, as well as around the Malvinas (Falkland) islands. The littoral zone, Patagonian gulfs and the continental shelf off Chubut, Río Negro and Buenos Aires state received less attention, and should be surveyed more intensively in the future. Only 2% of the species can be regarded as non-indigenous, all of them inhabiting biofouling communities in harbour environments. With the exception of some thoroughly surveyed localities, the number of species recorded for different areas of the coast, shelf and slope is estimated to be just a small fraction of the actual number of species present. A distinct diversity gradient was found, with species-rich stations located only in the southern shelf. Highest diversity occurred in shelf areas dominated by coarse sediments, and along a high-productivity shelf-break front. A remarkable decrease in species richness was found in inner and middle shelf areas off Chubut, Río Negro and Buenos Aires state. This pattern may be related to the Pacific origin of the Magellanic fauna, since the diversity of bryozoans is higher in the Pacific than in the Atlantic Ocean. The trend of species richness is, however, overemphasized by the fact that the least diverse faunistic assemblage occurs in areas where surveys have been relatively less frequent. An up-to-date checklist of species recorded for the study area is included. [source] The rise of methamphetamine in Southeast and East AsiaDRUG AND ALCOHOL REVIEW, Issue 3 2008REBECCA McKETIN Abstract Introduction and Aims. Southeast and East Asia has become a global hub for methamphetamine production and trafficking over the past decade. This paper describes the rise of methamphetamine supply and to what extent use of the drug is occurring in the region. Method and Design. The current review uses data collected through the Drug Abuse Information Network for Asia and the Pacific (DAINAP) and other available sources to analyse retrospectively methamphetamine trends within Southeast and East Asia. Results. Southeast and East Asia has experienced a methamphetamine epidemic in the past decade which began around 1997 and peaked in 2000,2001. While the situation has since stabilised in many countries, methamphetamine trafficking and use are still increasing in parts of the Mekong region and there is evidence of large-scale manufacture in Cambodia, Indonesia, Malaysia and the Philippines. Methamphetamine is typically smoked or ingested, but injection of the drug is apparent. Conclusion. While the peak of the methamphetamine epidemic has passed in parts of Southeast and East Asia, attention is needed to minimise the potential consequences of spreading methamphetamine production, trafficking and use in the Mekong region and in the peninsular and archipelago of Southeast Asia. [source] Prevalence of illicit drug use in Asia and the PacificDRUG AND ALCOHOL REVIEW, Issue 1 2007MADONNA L. DEVANEY Abstract This paper reports on the prevalence of drug use in Asia and the Pacific. It is based on the report "Situational analysis of illicit drug issues and responses in Asia and the Pacific", commissioned by the Australian National Council on Drugs Asia Pacific Drug Issues Committee. Review of existing estimates of the prevalence of people who use illicit drugs from published and unpublished literature and information from key informants and regional institutions was undertaken for the period 1998-2004. Estimates of the prevalence of people who use illicit drugs were conducted for 12 Asian and six Pacific Island countries. The estimated prevalence of those using illicit drugs ranges from less than 0.01% to 4.6%. Countries with estimated prevalence rates higher than 2% are Cambodia, Hong Kong, Philippines, Thailand, Indonesia, Laos and Malaysia. China, Myanmar and Vietnam have estimated prevalence rates ranging between less than 0.01% and 2%. Data to estimate prevalence rates was not available for Pacific Island countries and Brunei. Estimates of the prevalence of drug use are critical to policy development, planning responses and measuring the coverage of programs. However, reliable estimates of the numbers of people using illicit drugs are rare in Asia, particularly the Pacific. [source] Mollusk species diversity in the Southeastern Pacific: why are there more species towards the pole?ECOGRAPHY, Issue 2 2003Claudio Valdovinos The most ubiquitous and well recognized diversity pattern at large spatial scales is the latitudinal increase in species richness near the equator and decline towards the poles. Although several exceptions to this pattern have been documented, shallow water mollusks, the most specious group of marine invertebrates, are the epitome of the monotonic decline in species diversity toward higher latitudes along the Pacific and Atlantic coasts of North America. Here we analyze the geographic diversity of 629 mollusk species along the Pacific South American shelf. Our analyses are based on the most complete database of invertebrates assembled for this region of the world, consisting of latitudinal ranges of over 95% of all described mollusks between 10° and 55°S. Along this coast, mollusk diversity did not follow the typical latitudinal trend. The number of species remained constant and relatively low at intermediate latitudes and sharply increased toward higher latitudes, south of 42°S. This trend was explained by changes in shelf area, but not by sea surface temperature, unlike the pattern documented for Northern Hemisphere mollusks. Direct sampling of soft bottom communities along the gradient suggests that regional trends in species richness are produced by increased alpha diversity, and not only by artifacts produced by the increase in sampling area. We hypothesize that increased shelf area south of 42°S, geographic isolation produced by divergence of major oceanic currents, and the existence of refugia during glaciations, enabled species diversification. Radiation could have been limited by narrow continental shelves between 10°,42°. Asymmetries in latitudinal diversity trends between hemispheres show that there is not a single general factor determining large-scale diversity patterns. [source] Invasion success: does size really matter?ECOLOGY LETTERS, Issue 2 2002A. W. Miller The recent paper by Roy et al. (2001) presents a compelling relationship between range limit shifts, climatic fluctuations, and body size for marine bivalves in the fossil record. However, their extension of body size as a correlate for contemporary marine bivalve introductions is problematic and requires further scrutiny. Unlike their analysis of the fossil assemblage, the approach used for contemporary invasions does not adequately control for dispersal mechanism (vector) or source region. First, their analysis included mariculture species, intentionally introduced because of their large size, creating a vector-specific bias. Second, successful invaders from multiple source regions (Northern Hemisphere) were compared with potential invaders from a single source region (north-eastern Pacific), leaving both source and vector as uncontrolled variables. We present an analysis of body size for bivalve introductions from a single vector and source region, indicating no correlation between body size and invasion success when eliminating intentional introduction, source region and transport vector as confounding factors. [source] Developmental and Quiescent Subsidiaries in the Asia Pacific: Evidence from Hong Kong, Singapore, Shanghai, and SydneyECONOMIC GEOGRAPHY, Issue 2 2003Jessie P. H. Poon Abstract: Examining "embedded" economic and social relations has become a popular theme among economic geographers who are interested in explaining the durability of place in supporting economic activities. This article explores the relationship between embeddedness and technology-oriented functions among three types of subsidiaries (regional headquarters, regional offices, and local offices) and for four cities: Hong Kong, Shanghai, Singapore, and Sydney. Using survey data from firms, we show that quiescent or branch plant-like subsidiaries, rather than developmental firms, dominate the region. But among developmental subsidiaries, returns on embeddedness are not always obvious. Embeddedness and developmental subsidiaries are most significantly correlated with manufacturing regional headquarters. However, a small group of subsidiaries (local and regional offices) also perform developmental functions, despite their relative newness and lack of embed-dedness in the region. [source] A pyrene-degrading consortium from deep-sea sediment of the West Pacific and its key member Cycloclasticus sp.ENVIRONMENTAL MICROBIOLOGY, Issue 8 2008Summary A pyrene-degrading bacterial consortium was obtained from deep-sea sediments of the Pacific Ocean. The consortium degraded many kinds of polycyclic aromatic hydrocarbons (PAHs), including naphthalene, phenanthrene, pyrene, acenaphthene, fluorene, anthracene, fluoranthene, 2-methylnaphthalene and 2,6-dimethylnaphthalene, but it did not grow with chrysene and benzo[,]pyrene. With methods of plate cultivation and polymerase chain reaction,denaturing gradient gel electrophoresis (PCR-DGGE), 72 bacteria belonging to 22 genera were detected from this consortium. Among the detected bacteria, the following genera frequently occurred: Flavobacterium, Cycloclasticus, Novosphingobium, Halomonas, Achromobacter, Roseovarius and Alcanivorax. The first two genera showed the strongest bands in denaturing gradient gel electrophoresis (DGGE) profiles and appeared in all PAH treatments. By now, only one isolate designated P1 was confirmed to be a pyrene degrader. It was identified to be Cycloclasticus spirillensus (100%). Although P1 can degrade pyrene independently, other bacteria, such as Novosphingobium sp. (Band 14), Halomonas sp. (Band 16) and an unidentified bacterium (Band 35), were involved in pyrene degradation in some way; they persist in the consortium in the test of dilution to extinction if only the consortium was motivated with pyrene. However, the secondary most important member Flavobacterium sp. evaded from the community at high dilutions. As a key member of the consortium, P1 distinguished itself by both cell morphology and carbon source range among the isolates of this genus. Based on intermediate analyses of pyrene degradation, P1 was supposed to take an upper pathway different from that previously reported. Together with the results of obtained genes from P1 homology with those responsible for naphthalene degradation, its degradation to pyrene is supposed to adopt another set of genes unique to presently detected. Summarily, an efficient pyrene-degrading consortium was obtained from the Pacific Ocean sediment, in which Cycloclasticus bacterium played a key role. This is the first report to exploit the diversity of pyrene-degrading bacteria in oceanic environments. [source] Implications of REACH for developing countriesENVIRONMENTAL POLICY AND GOVERNANCE, Issue 1 2008Frank Ackerman Abstract The new European Union (EU) chemicals regulation, the Registration, Evaluation and Authorisation of Chemicals, or REACH, went into effect in 2007. In the extensive advance discussion of the expected impacts of REACH, questions were raised about the effects of this new chemical policy on developing countries. In particular, will it harm the economies of the group of African, Caribbean and Pacific (ACP) countries that historically have been connected to Europe? We found, in brief, that there are only limited, isolated cases where REACH could be problematical for ACP exporters. Almost all ACP exports subject to REACH face insignificant obstacles from the new regulation. Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment. [source] Contaminant-associated alteration of immune function in black-footed albatross (Phoebastria nigripes), a North Pacific predatorENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 9 2007Myra E. Finkelstein Abstract Environmental pollution is ubiquitous and can pose a significant threat to wild populations through declines in fitness and population numbers. To elucidate the impact of marine pollution on a pelagic species, we assessed whether toxic contaminants accumulated in black-footed albatross (Phoebastria nigripes), a wide-ranging North Pacific predator, are correlated with altered physiological function. Blood samples from adult black-footed albatrosses on Midway Atoll, part of the Hawaiian (USA) archipelago, were analyzed for organochlorines (e.g., polychlorinated biphenyls [PCBs] and chlorinated pesticides), trace metals (silver, cadmium, tin, lead, chromium, nickel, copper, zinc, arsenic, selenium, and total mercury), and a sensitive physiological marker, peripheral white blood cell immune function (mitogen-induced lymphocyte proliferation and macrophage phagocytosis). We found a positive significant relationship between organochlorines, which were highly correlated within individual birds (p < 0.001, r > 0.80, Spearman correlation for all comparisons; PCBs, 160 ± 60 ng/ml plasma [mean ± standard deviation]; DDTs, 140 ± 180 ng/ml plasma; chlordanes, 7.0 ± 3.6 ng/ml plasma; hexachlorobenzene, 2.4 ± 1.5 ng/ml plasma; n = 15) and increased lymphocyte proliferation (p = 0.020) as well as percentage lymphocytes (p = 0.033). Mercury was elevated in black-footed albatrosses (4,500 ± 870 ng/ml whole blood, n = 15), and high mercury levels appeared to be associated (p = 0.017) with impaired macrophage phagocytosis. The associations we documented between multiple contaminant concentrations and immune function in endangered black-footed albatrosses provide some of the first evidence that albatrosses in the North Pacific may be affected by environmental contamination. Our results raise concern regarding detrimental health effects in pelagic predators exposed to persistent marine pollutants. [source] Chlorinated hydrocarbons in flatfishes from the Southern California, USA, BightENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 6 2000Kenneth Schiff Abstract Alhough inputs of chlorinated hydrocarbon compounds to the Southern California Bight (SCB) are presently low, historical deposits represent a source of bioaccumulation potential to sediment-associated fauna. To assess this bioaccumulation potential, 14 chlorinated hydrocarbon classes were measured in livers of three species of flatfish collected from 63 randomly selected sites on the coastal shelf between Point Conception and the United States,Mexico international border. Tissue contamination was widespread throughout the SCB, but was limited to just two chlorinated hydrocarbon classes. Virtually 100% of Pacific sanddab (Citharichthys sordidus) and longfin sanddab (Citharichthys xanthostigma) populations were estimated to be contaminated with dichlorodiphenyltrichloroethane (total DDT = sum of o,p, and p,p, isomers of DDT + dichlorodiphenyldichloroethylene [DDE] + dichlorodiphenyldichloroethane [DDD]) and/or polychlorinated biphenyls (total PCBs). Total DDT also contaminated the majority (64%) of the Dover sole (Microstomus pacificus) population in the SCB. Total PCB measurements in tissues of SCB flatfish were dominated by 12 congeners (52, 66, 87, 101, 105, 118, 128, 138, 153, 170, 180, and 187), which averaged 95% of the combined mass of the 27 congeners analyzed. Sediment concentrations (normalized by total organic carbon content) accounted for most of the variability observed in tissue concentrations (normalized by lipid content) for 8 of these 12 congeners and total PCBs. Normalized sediment concentrations were also significantly correlated to normalized tissue concentrations for total DDT and p,p,-DDE. Tissue concentrations measured in this study from reference areas of the SCB were compared to tissue concentrations measured from reference areas in studies conducted in 1977 and 1985. Total DDT and total PCB liver concentrations were found to have decreased one to two orders of magnitude in Pacific and longfin sanddabs between 1985 and 1994. Total DDT and total PCB liver concentrations decreased 5- to 35-fold in Dover sole between 1977 and 1994. [source] Oceanic influence on the precipitation of the south-east of VenezuelaENVIRONMETRICS, Issue 3 2002Lelys Guenni Abstract The Caroní catchment located in the south-east of Venezuela accounts for 70 per cent of the total hydropower energy of the country. On a year to year basis, it has been shown that low frequency large scale ocean-atmosphere phenomena are highly coupled to the hydroclimatology of the region, El Niño-Southern Oscillation (ENSO) being a major forcing mechanism of climatic and hydrological anomalies. Regional differences in amplitude and timing are due to complex orographic interactions, land surface-atmosphere feedback mechanisms and the evolution of dominant synoptic meteorological conditions. A detailed analysis of the relationship between rainfall and several large scale ocean-atmospheric variables was carried out to determine the potential use of large scale climatic information as predictors of the rainfall anomalies over the region. The problem was tackled in two ways: (a) first a seasonal dynamic rainfall model was fitted to monthly rainfall for different locations. In this case rainfall is assumed as a normal variate w which has been transformed to account for its departure from normality and truncated to account for the positive probability mass of zero values, which corresponds to negative values of the normal variable. The time series of the model parameters and the macroclimatic variables are inspected for their potential relationship with local rainfall via the stochastic model. (b) Second, dynamic linear regression models between the macroclimatic variables as predictors and the rainfall anomalies as predictant were fitted to evaluate and quantify the significance of these dependencies. Consistent patterns are observed with the Tropical Atlantic and Pacific ocean temperature anomalies, in which a significant negative relationship has been present since 1976, indicating an overall decrease (increase) in rainfall when the Pacific and the Tropical Atlantic are warmer (colder) than normal. In all cases the results suggest that the relationships between rainfall anomalies and the macroclimatic variables are not constant with time. Copyright © 2002 John Wiley & Sons, Ltd. [source] El Niño, climate change, and Southern African climateENVIRONMETRICS, Issue 4 2001Simon J. Mason Abstract The El Niño phenomenon involves a large-scale warming of the equatorial eastern and central Pacific Ocean. Recent developments in the El Niño,Southern Oscillation (ENSO) phenomenon have raised concerns about climate change. In this review paper, these recent developments are critically assessed and forecasts of possible future changes are reviewed. Since the late-1970s, El Niño episodes have been unusually recurrent, while the frequency of strong La Niña events has been low. Prolonged/recurrent warm event conditions of the first half of the 1990s were the result of the persistence of an anomalously warm pool near the date line, which, in turn, may be part of an abrupt warming trend in tropical sea-surface temperatures that occurred in the late-1970s. The abrupt warming of tropical sea-surface temperatures has been attributed to the enhanced-greenhouse effect, but may be indicative of inter-decadal variability: earlier changes in the frequency of ENSO events and earlier persistent El Niño and La Niña sequences have occurred. Most forecasts of ENSO variability in a doubled-CO2 climate suggest that the recent changes in the tropical Pacific are anomalous. Of potential concern, however, is a possible reduction in the predictability of ENSO events given a warmer background climate. El Niño events usually are associated with below-normal rainfall over much of southern Africa. Mechanisms for this influence on southern African climate are discussed, and the implications of possible changes in ENSO variability on the climate of the region are assessed. Recent observed changes in southern African climate and their possible relationships with trends in ENSO variability are investigated. The El Niño influence on rainfall over southern Africa occurs largely because of a weakening of tropical convection over the subcontinent. A warming of the Indian Ocean during El Niño events appears to be important in providing a teleconnection from the equatorial Pacific Ocean. The abrupt warming of the tropical Pacific and Indian oceans in the late-1970s is probably partly responsible for increasing air temperatures over southern Africa, and may have contributed to a prolongation of predominantly dry conditions. A return to a wet phase appears to have occurred, despite the persistence of anomalously high sea-surface temperatures associated with the late-1970s warming, and a record-breaking El Niño in 1997/98. Copyright © 2001 John Wiley & Sons, Ltd. [source] Association amongst factors thought to be important by instructors in dental education and perceived effectiveness of these instructors by studentsEUROPEAN JOURNAL OF DENTAL EDUCATION, Issue 4 2004D. W. Chambers It is hypothesised that dental educators have perceptions of their roles as effective teachers. It is expected that subject matter expertise would be amongst the components of such personal philosophies of education, but it is unclear whether faculty member self-perceptions carry over into student ratings of instructors' effectiveness. A 20-item survey of ,Teaching Characteristics' was completed by 86% of full-time and 64% of the part-time faculty members at the University of the Pacific. Respondents distributed 100 points amongst the descriptions of what makes an effective instructor. The responses were factor-analysed, resulting in four general faculty ,types' that explained about 50% of the variance in ratings: expert, enthusiast, judicial and good soldier. Student ratings for the 2 years running up to the date of the survey administration were used to gauge student perceptions of instructor effectiveness. Faculty members who placed emphasis on expertise as key to being a good instructor received significantly lower ratings for teacher effectiveness from students than did other faculty members. Faculty members who conceived their roles as motivating students, explaining difficult concepts, displaying interest in the subject, showing compassion and caring, and being proactive tended to receive high ratings for teaching effectiveness from students. [source] VICARIANCE AND DISPERSAL ACROSS BAJA CALIFORNIA IN DISJUNCT MARINE FISH POPULATIONSEVOLUTION, Issue 7 2003Giacomo Bernardi Abstract., Population disjunctions, as a first step toward complete allopatry, present an interesting situation to study incipient speciation. The geological formation of the Baja California Peninsula currently divides 19 species of fish into disjunct populations that are found on its Pacific Coast and in the northern part of the Gulf of California (also called the Sea of Cortez), but are absent from the Cape (Cabo San Lucas) region. We studied the genetic makeup of disjunct populations for 12 of these 19 fish species. Phylogeographic patterns for the 12 species can be separated into two major classes: a first group (eight species) showed reciprocal monophyly and high genetic divergence between disjunct populations. A second group (four species) displayed what appeared to be panmictic populations. Population structure between Pacific Coast populations, across the Punta Eugenia biogeographic boundary, was also evaluated. While dispersal potential (inferred by pelagic larval duration) was a poor predictor of population structure between Gulf of California and Pacific populations, we found that population genetic subdivision along the Pacific Coast at Punta Eugenia was always positively correlated with differentiation between Pacific and Gulf of California populations. Vicariant events, ongoing gene flow, and ecological characteristics played essential roles in shaping the population structures observed in this study. [source] Bacterial diversity in the breadcrumb sponge Halichondria panicea (Pallas)FEMS MICROBIOLOGY ECOLOGY, Issue 1 2006Antje Wichels Abstract The aim of this study was to investigate the diversity and variability of bacterial communities associated with the marine sponge Halichondria panicea with respect to tissue compartmentalization as well as seasonal and small-scale geographic variation. Diversity of microorganisms in sponges was investigated recently, but work on the variability and succession of associated bacterial communities is rare. Despite some information on Pacific and Mediterranean sponges, it is still uncertain whether bacteria and sponges are specifically associated. In this study, H. panicea specimens were sampled throughout the year at different stations around the island of Helgoland (North Sea) and investigated using molecular tools. The bacterial community associated with H. panicea was diverse, consisting of one denaturing gradient gel electrophoresis (DGGE) band occurring in most ,tissue' samples and additional variable bands. Variability was observed between different sponge fractions (i.e. the aquiferous system and the ,tissue'), sampling locations, and sampling dates. A PCR-DGGE specific for the Roseobacter group of marine Alphaproteobacteria displayed low diversity and a marked similarity between all samples. Phylogenetic analysis also pointed to specific Alphaproteobacteria of the Roseobacter group, which was predominant in most sponge ,tissue' samples. We conclude that H. panicea harbour a specific Roseobacter population with varying bacterial co-populations occurring seasonally or on a small-scale geographically, sometimes even dominating the bacterial community. [source] Ecological effects of regime shifts in the Bering Sea and eastern North Pacific OceanFISH AND FISHERIES, Issue 2 2002Ashleen J Benson Abstract Large-scale shifts occurred in climatic and oceanic conditions in 1925, 1947, 1977, 1989 and possibly 1998. These shifts affected the mix and abundance of suites of coexisting species during each period of relative environmental stability,from primary producers to apex predators. However, the 1989 regime shift was not a simple reversal of the 1977 shift. The regime shifts occurred abruptly and were neither random variations nor simple reversals to the previous conditions. Timing of these anomalous environmental events in the North Pacific Ocean appears to be linked to physical and biological responses in other oceanic regions of the world. Changes in the atmospheric pressure can alter wind patterns that affect oceanic circulation and physical properties such as salinity and depth of the thermocline. This, in turn, affects primary and secondary production. Data from the North Pacific indicate that regime shifts can have opposite effects on species living in different domains, or can affect similar species living within a single domain in opposite ways. Climatic forcing appears to indirectly affect fish and marine mammal populations through changes in the distribution and abundance of their predators and prey. Effects of regime shifts on marine ecosystems are also manifested faster at lower trophic levels. Natural variability in the productivity of fish stocks in association with regime shifts indicates that new approaches to managing fisheries should incorporate climatic as well as fisheries effects. [source] Acoustic characterization of biological backscatterings in the Kuroshio-Oyashio inter-frontal zone and subarctic waters of the western North Pacific in springFISHERIES OCEANOGRAPHY, Issue 6 2009HIROTO MURASE Abstract The acoustic characteristics of biological backscattering in the western North Pacific were studied to verify expert knowledge on species composition in the echosigns. The survey was conducted in the Kuroshio-Oyashio inter-frontal zone and the subarctic waters in April 2003. The species composition of backscatterings was identified by using midwater trawl, Isaacs-Kidd midwater trawl and Bongo net. The differences of mean volume backscattering strengths between 120 and 38 kHz (,MVBS120,38) were calculated for the backscatterings. Six types of backscatterings were classified based on the results of net samples and the ,MVBS120,38. The ,MVBS120,38 of each group was as follows: copepods 13.7,17.3 dB, krill 11.6,15.3 dB, Japanese anchovy ,1.6 to 1.1 dB, a myctophid, Diaphus theta,0.8 dB, sand lance 6.1 dB and larvae and juveniles of pelagic and mesopelagic fish ,9.6 to ,4.0 dB. The results suggest that biological backscatterings in the Kuroshio-Oyashio inter-frontal zone and subarctic waters of the western North Pacific in spring can be characterized by using ,MVBS. [source] Transport and environmental temperature variability of eggs and larvae of the Japanese anchovy (Engraulis japonicus) and Japanese sardine (Sardinops melanostictus) in the western North Pacific estimated via numerical particle-tracking experimentsFISHERIES OCEANOGRAPHY, Issue 2 2009SACHIHIKO ITOH Abstract Numerical particle-tracking experiments were performed to investigate the transport and variability in environmental temperature experienced by eggs and larvae of Pacific stocks of the Japanese anchovy (Engraulis japonicus) and Japanese sardine (Sardinops melanostictus) using high-resolution outputs of the Ocean General Circulation Model for the Earth Simulator (OFES) and the observed distributions of eggs collected from 1978 to 2004. The modeled anchovy individuals tend to be trapped in coastal waters or transported to the Kuroshio,Oyashio transition region. In contrast, a large proportion of the sardines are transported to the Kuroshio Extension. The egg density-weighted mean environmental temperature until day 30 of the experiment was 20,24°C for the anchovy and 17,20°C for the sardine, which can be explained by spawning areas and seasons, and interannual oceanic variability. Regression analyses revealed that the contribution of environmental temperature to the logarithm of recruitment per spawning (expected to have a negative relationship with the mean mortality coefficient) was significant for both the anchovy and sardine, especially until day 30, which can be regarded as the initial stages of their life cycles. The relationship was quadratic for the anchovy, with an optimal temperature of 21,22°C, and linear for the sardine, with a negative coefficient. Differences in habitat areas and temperature responses between the sardine and anchovy are suggested to be important factors in controlling the dramatic out-of-phase fluctuations of these species. [source] Establishing climate,growth relationships for yelloweye rockfish (Sebastes ruberrimus) in the northeast Pacific using a dendrochronological approachFISHERIES OCEANOGRAPHY, Issue 5 2008BRYAN A. BLACK Abstract We applied dendrochronology (tree-ring) methods to develop multidecadal growth chronologies from the increment widths of yelloweye rockfish (Sebastes ruberrimus) otoliths. Chronologies were developed for the central California coast, a site just north of Vancouver Island, British Columbia, and at Bowie Seamount west of the Queen Charlotte Islands, British Columbia. At each site, synchronous growth patterns were matched among otoliths via the process of cross-dating, ensuring that the correct calendar year was assigned to all increments. Each time series of growth-increment measurements was divided by the values predicted by a best-fit negative exponential function, thereby removing age-related trends. These detrended time series were averaged into a master chronology for each site, and chronologies were correlated with monthly averages of sea surface temperatures, upwelling, the Northern Oscillation Index, and the Pacific Decadal Oscillation. The two northern growth chronologies positively correlated with indices of warm ocean conditions, especially from the prior summer through the spring of the current year. During the same period, the California chronology positively correlated with indices of cool ocean conditions, indicating an opposing productivity regime for yelloweye rockfish between the California Current and the Gulf of Alaska. Overall, this study demonstrates how tree-ring techniques can be applied to quickly develop annually resolved chronologies and establish climate,growth relationships across various temporal and spatial scales. [source] Interannual and seasonal variability of the diversity and structure of ichthyoplankton assemblages in the central Mexican PacificFISHERIES OCEANOGRAPHY, Issue 3 2008C. FRANCO-GORDO Abstract We examined larval fish diversity and assemblage structure off the central coast of the Mexican Pacific from December 1995 through December 1998, including the 1997,98 El Niño event. A total of 132 taxa were recorded, the dominant species being Bregmaceros bathymaster, Dormitator latifrons, and Harengula thrissina (90, 1.9, and 0.8% of the total abundance, respectively). Only B. bathymaster, D. latifrons, and Gobionellus sp. occurred in all samples. The effects of the 1997,98 El Niño on ichthyoplankton diversity were significant, but typical seasonal patterns were also detected. Diversity null models were used to determine the structural changes in the assemblage related to El Niño; both richness and evenness of the species were highest during this event. The most parsimonious models of assemblage organization include El Niño and seasonality as the most significant environmental variability sources. The small-scale spatial variability expressed as the cross-shore gradient was not significant. The dominant species group formed by B. bathymaster, D. latifrons, and Vinciguerria lucetia typifies, in terms of similarity, both the pre-El Niño and El Niño periods; abundance differed between periods. The El Niño period was characterized locally by the dominant Bentosema panamense and H. thrissina, by the rare Euthynnus lineatus, and species of Lutjanus. Seasonality produced changes also in the relative frequencies of the dominant species plus the occurrence of rare forms. The average taxonomical distinctness, considered herein as an indicator of functional diversity, reflected the seasonal variability of the assemblages, aside from El Niño; this index showed lowest values during tropical and transitional periods, both characterized by warm, oligotrophic waters. The high dominance of B. bathymaster in the area and its effect on diversity stabilized the local ichthyoplankton assemblage. An upgraded analysis of diversity allowed a more detailed description of the variability in this assemblage, thus stressing the differential effects of El Niño at distinct latitudes. [source] | |||||||||||||||||||||||||||||||||||||||||||