Southwestern Pacific Ocean Research Articles

A new species ofParaglypturus(Crustacea: Decapoda: Axiidea: Callianassidae) from a vent field in the Tonga Arc of the south-western Pacific Ocean

A new species of callianassid ghost shrimp,Paraglypturus tonganussp. nov., is described and illustrated on the basis of five specimens that were collected from sediments in a vent field of the Tonga Arc, south-western Pacific Ocean. This new species is morphologically very similar toP. calderusTürkay & Sakai, 1995, the type species of the genusParaglypturusTürkay & Sakai, 1995. It differs fromP. calderusmainly in the absence (vs. presence inP. calderus) of an anterolateral row of setal pores on the carapace; the endopod of the second maxilliped, with a dactylus bearing stiff and thick serrate setae at the apex (vs. without inP. calderus); a yellow circular structure located on the ventral surface on the uropodal endopod (vs. on the dorsal surface on the uropodal exopod inP. calderus); and the articulation structure of the first pleopod in males (uniarticulate inP. tonganusvs. biarticulate inP. calderus). The new species is the first record of a ghost shrimp from a vent field of the Tonga Arc, and also the second reported species of the genusParaglypturus.

Causes for intraseasonal sea surface salinity variability in the western tropical Pacific Ocean and its seasonality

AbstractPronounced intraseasonal variability (ISV; 20–90 day) of sea surface salinity (SSS) with a standard deviation of 0.12–0.20 psu is detected in the western tropical Pacific Ocean (PO) from measurements of Aquarius/SAC‐D satellite. These variations are not spatially uniform but show distinct regional features. The Hybrid Coordinate Ocean Model (HYCOM) well simulated the observed SSS variations, and a suite of parallel experiments were performed to understand the underlying physical processes. Surface forcing by atmospheric intraseasonal oscillations which are dominated by the Madden‐Julian oscillation (MJO) is largely responsible for producing the SSS ISV, while ocean internal variability plays a secondary role. Impact of atmospheric forcing is primarily through precipitation and wind stress‐driven oceanic processes. Their relative importance shows spatial variations. They have approximately equal importance in the western equatorial PO west of 155°E and the southwestern tropical PO. Wind stress effect dominates SSS ISV in the equatorial PO east of 155°E, while precipitation effect is larger in the northwestern tropical PO. In comparison, the effect of evaporation induced by wind speed change is smaller. The SSS ISV also shows evident seasonality in some areas, particularly in the far western equatorial basin and southwestern tropical PO. During boreal summer (winter), SSS ISV is enhanced (weakened) in the northwestern PO and weakened (enhanced) in the southwestern PO. Comparing with the strength of atmospheric forcing, seasonal variation of the ocean state, especially the mixed layer depth, is generally more important in causing such seasonality.

Impact of cross-reef water fluxes on lagoon dynamics: a simple parameterization for coral lagoon circulation model, with application to the Ouano Lagoon, New Caledonia

This manuscript presents a combined experimental and numerical study of the impact of cross-reef fluxes on coral reef lagoon dynamics. The selected field site is the Ouano Lagoon (New Caledonia Island, France) in the South Western Pacific Ocean. Measurements of wave transformation above the reef and current profiles through passages and reef openings have been carried out during a 3-month survey. Data analysis reveals the preponderant roles played by both tides and waves on the lagoon dynamics. Based on field data, a simple parameterization of cross-reef fluxes is implemented in a coastal lagoon circulation model and a satisfactory agreement is found between parameterized model and field results. The model is thus used as a numerical experimental tool in order to analyse the cross-reef flows’ possible influence on a narrow lagoon dynamics. The results highlight the importance of cross-reef fluxes induced by wave breaking over the reef barrier on the whole lagoon circulation and water properties.

Spatial genetic subdivision among populations of the highly migratory black marlin Istiompax indica within the central Indo-Pacific

The black marlin Istiompax indica is a highly migratory species and as a result is expected to show little genetic population structure throughout its broad geographic range. Tissue samples from 183 I. indica were collected from three geographic regions within the central Indo-Pacific and analysed using mitochondrial and nuclear DNA markers. Nuclear genetic heterogeneity was found among populations in the south-western Pacific Ocean, eastern Indian Ocean and South China Sea (significant FST values of 0.013–0.037). Combining information from nuclear markers with published movement and reproductive data suggests that reproductive philopatry plays a role in maintaining contemporary I. indica population structure. Analyses of the mitochondrial control region did not reflect this pattern; however, it identified historical population structure. Differing patterns of genetic population structure revealed by mitochondrial and nuclear markers demonstrated that a transition must have occurred between historical and contemporary population structures. This restructuring presumably reflects a species whose populations have become genetically isolated before experiencing a period of secondary contact. The spatial subdivision evident among populations indicates that I. indica in this central Indo-Pacific region should be managed as three independent stocks, to guide the sustainability of this fisheries resource.

Surviving under pressure and protection: a review of the biology, ecology and population status of the highly vulnerable grouper Epinephelus daemelii

Epinephelus daemelii is a threatened serranid grouper species that is restricted to the south-western Pacific Ocean, ranging from eastern Australia to northern New Zealand and the Kermadec Islands. Declines in its abundance due to fishing pressure were reported as early as 1916. Aspects of this species’ biology and behaviour that make it vulnerable include its longevity, late age at maturity, protogynous hermaphroditism, territoriality and limited shallow reef habitat. Adults prefer complex habitat with caves and overhangs at depths of less than 50m, whereas juveniles live in rock pools, shallow intertidal reefs and estuaries. Epinephelus daemelii lives at least 65 years and reaches 170-cm total length. Individuals change sex from female to male at ~100–110cm and ~25 years. Absence of large (>100cm) fish across a large part of their range has implications for reproduction. Although nearly fully protected, incidental bycatch still occurs. A lack of long-term data hinders determination of population status, but abundance appears to be much lower than before, except in remote regions (Kermadec Islands, Elizabeth and Middleton reefs) with extensive no-fishing areas. Further prohibitions on fishing in key locations are likely to be important for the recovery and long-term survival of this species.

Services for people with communication disability in Fiji: barriers and drivers of change

The World Health Organization's World report on disability calls upon all nations to 'remove the barriers which prevent [people with disabilities] from participating in their communities; getting a quality education, finding decent work, and having their voices heard' (p. 5). People with communication disability (PWCD), as a consequence of their atypical communication, may be more likely to be excluded from society, and denied their basic human rights, than other people with disability. Fiji, a multicultural and multilingual nation in the south-western Pacific Ocean, has limited services for PWCD. Service providers in Fiji include disability care workers, special education teachers, traditional healers, and a small number of visiting volunteer speech-language pathologists. This paper outlines the historical and current barriers to, and drivers of change for, service development for PWCD in Fiji. Five barriers to service development for PWCD in Fiji were identified. (1) A major structural barrier is the small population size to develop appropriate infrastructure including professional education programs. (2) Geographical barriers include the dispersed geography across 300 islands, low population density, the rural-urban divide, and risk of disaster from cyclones and flooding. (3) Linguistic diversity, while culturally important, can present a barrier to the provision of quality services that are available in the languages spoken by PWCD. (4) Cultural barriers include historical political instability, although Fiji has become more stable due to the recent democratic elections. The social climate affects development of services that are appropriate for different dominant cultural groups. (5) Financial barriers include low gross domestic product, low financial security and low human development index; however, the financial outlook for Fiji is steadily improving due to the change in political stability. Three levels of drivers of change were identified. Macro-level drivers included Fiji's endorsement of international policy and increased globalisation (eg tourism). Meso-level drivers of change included receipt of foreign aid and support from international non-government organisations, development of disability-inclusive legislation and policy within Fiji, and strengthening of government policies that support disabled people's organisations. Micro-level drivers of change included establishment of disabled people's organisations by consumers, adoption of disability-inclusive policy and procedures by service providers, and changes in the perceptions of disability within the general community. Fijian prevalence data confirms that there is an underserved population of PWCD in need of specialist services. Significant advocacy work in the disability field by Fijian and international disabled people's organisations has led to the Fiji government signing international policy (eg Convention on the Rights of Peoples with Disabilities), inclusion of disability rights in national legislation (eg 2013 Constitution of Fiji Islands) and localised policy and practice documentation (eg inclusive education policy by the Fiji Islands Ministry of Education). Continued service development is required if Fijians with communication disability are to have their needs met. The drivers of change at all levels are positioned well to overcome current barriers to change; however, a coordinated approach including macro-, meso-, and micro-level drivers is required to ensure the future development of adequate services for PWCD in Fiji.

Monomia calla, a new species of swimming crab (Decapoda, Portunidae) from Madagascar and the Philippines.

A new species of portunid crab (Brachyura: Portunidae) from southern Madagascar and central Philippines is described. Monomia calla sp. nov. is most similar in morphology toM. lecromi (Moosa, 1996) from the Chesterfield Islands in the southwestern Pacific Ocean, and M. rubromarginata (Lanchester, 1900) from the South China Sea, Singapore, Malay Archipelago and the northern half of Australia. The new species can be easily distinguished from all congeners by the distinctive morphology of the male first gonopod. The number of species of the Indo-West Pacific genus Monomia now stands at 12.

Larvae of the lanternfish Lampanyctus intricarius (Myctophidae) from the southwestern Pacific Ocean

Larvae of the lanternfish Lampanyctus intricarius (Myctophidae) from the southwestern Pacific Ocean

Distinctiveness of Pacific Robin subspecies in Vanuatu revealed from disparate patterns of sexual dichromatism, plumage colouration, morphometrics and ancient DNA

The Pacific Robin (Petroica multicolor) is a polytypic species, with 14 subspecies recognised in the tropical south-western Pacific Ocean. Like most of the avifauna of this region, the Pacific Robin has received little taxonomic attention since early works, such as those by Ernst Mayr in the 1930s–1950s. Here, we used mitochondrial DNA (mtDNA), spectrophotometry of plumage colouration and morphological data to examine patterns of sexual dichromatism, and phenotypic and genetic variation of Pacific Robins in the Vanuatu Archipelago. We have shown for the first time that subspecies in Vanuatu display three types of sexual dichromatism: typical marked sexual dichromatism, and reduced sexual dichromatism, in which both sexes have either elaborate masculinised plumage or drab feminised plumage. Different types of sexual dichromatism were not correlated with phylogenetic relationships. We also find that distinctive mtDNA, bill-length and colour of the throat plumage support the naming of a new subspecies for the population on Tanna Island, P. m. tannensis subsp. nov., which has long been treated as consubspecific with that on nearby Aneityum Island. Our study highlights the importance of revisiting the taxonomy and evolutionary history of other Pacific Ocean avifauna with molecular data and quantitative tests of phenotypic differentiation between island forms.

Two new species of Platoma (Schizymeniaceae) from the western South Pacific Ocean

:Recent collections in northern New Zealand and New Caledonia revealed a single undescribed species of Platoma in each of these countries. Platoma novae-zealandiae sp. nov. is distinguished from its New Caledonian congener by its less foliose habit, subterete to flattened branches decreasing in width with increasing level of branching, distinctive protuberant ostiolate cystocarps, and large granular ‘gland’ cells. These features contrast with the morphology of Platoma novae-caledoniae sp. nov., which was irregularly to pseudodichotomously branched, with branches of almost equal width throughout, more blade-like and polymorphic, with barely protuberant nonostiolate cystocarps and uniformly refractive gland cells. These two species add to the regional floras of these highly biodiverse areas. These new taxa of Platoma increase the total number of species to 10; of these, five are known from the western Pacific, of which four are endemic to the region.

Population structure of humpback whales in the western and central South Pacific Ocean as determined by vocal exchange among populations

For cetaceans, population structure is traditionally determined by molecular genetics or photographically identified individuals. Acoustic data, however, has provided information on movement and population structure with less effort and cost than traditional methods in an array of taxa. Male humpback whales (Megaptera novaeangliae) produce a continually evolving vocal sexual display, or song, that is similar among all males in a population. The rapid cultural transmission (the transfer of information or behavior between conspecifics through social learning) of different versions of this display between distinct but interconnected populations in the western and central South Pacific region presents a unique way to investigate population structure based on the movement dynamics of a song (acoustic) display. Using 11 years of data, we investigated an acoustically based population structure for the region by comparing stereotyped song sequences among populations and years. We used the Levenshtein distance technique to group previously defined populations into (vocally based) clusters based on the overall similarity of their song display in space and time. We identified the following distinct vocal clusters: western cluster, 1 population off eastern Australia; central cluster, populations around New Caledonia, Tonga, and American Samoa; and eastern region, either a single cluster or 2 clusters, one around the Cook Islands and the other off French Polynesia. These results are consistent with the hypothesis that each breeding aggregation represents a distinct population (each occupied a single, terminal node) in a metapopulation, similar to the current understanding of population structure based on genetic and photo-identification studies. However, the central vocal cluster had higher levels of song-sharing among populations than the other clusters, indicating that levels of vocal connectivity varied within the region. Our results demonstrate the utility and value of using culturally transmitted vocal patterns as a way of defining connectivity to infer population structure. We suggest vocal patterns be incorporated by the International Whaling Commission in conjunction with traditional methods in the assessment of structure.

Mercury accumulation in hydrothermal vent mollusks from the southern Tonga Arc, southwestern Pacific Ocean

We provide the mercury (Hg) and monomethylmercury (MMHg) levels of the plume water, sulfide ore, sediment, and mollusks located at the hydrothermal vent fields of the southern Tonga Arc, where active volcanism and intense seismic activity occur frequently. Our objectives were: (1) to address the potential release of Hg from hydrothermal fluids and (2) to examine the distribution of Hg and MMHg levels in hydrothermal mollusks (mussels and snails) harboring chemotrophic bacteria. While high concentrations of Hg in the sediment and Hg, As, and Sb in the sulfide ore indicates that their source is likely hydrothermal fluids, the MMHg concentration in the sediment was orders of magnitude lower than the Hg (<0.001%). It suggests that Hg methylation may have not been favorable in the vent field sediment. In addition, Hg concentrations in the mollusks were much higher (10–100 times) than in other hydrothermal vent environments, indicating that organisms located at the Tonga Arc are exposed to exceedingly high Hg levels. While Hg concentration was higher in the gills and digestive glands than in the mantles and residues of snails and mussels, the MMHg concentrations in the gills and digestive glands were orders of magnitude lower (0.004–0.04%) than Hg concentrations. In summary, our results suggest that the release of Hg from the hydrothermal vent fields of the Tonga Arc and subsequent bioaccumulation are substantial, but not for MMHg.

Impact of Climatic Factors on Albacore Tuna &amp;lt;i&amp;gt;Thunnus alalunga&amp;lt;/i&amp;gt; in the South Pacific Ocean

Over the years there has been growing interest regarding the effects of climatic variations on marine biodiversity. The exclusive economic zones of South Pacific Islands and territories are home to major international exploitable stocks of albacore tuna (Thunnus alalunga); however the impact of climatic variations on these stocks is not fully understood. This study was aimed at determining the climatic variables which have impact on the time series stock fluctuation pattern of albacore tuna stock in the Eastern and Western South Pacific Ocean which was divided into three zones. The relationship of the climatic variables for the global mean land and ocean temperature index (LOTI), the Pacific warm pool index (PWI) and the Pacific decadal oscillation (PDO) was investigated against the albacore tuna catch per unit effort (CPUE) time series in Zone 1, Zone 2 and Zone 3 of the South Pacific Ocean from 1957 to 2008. From the results it was observed that LOTI, PWI and PDO at different lag periods exhibited significant correlation with albacore tuna CPUE for all three areas. LOTI, PWI and PDO were used as independent variables to develop suitable stock reproduction models for the trajectory of albacore tuna CPUE in Zone 1, Zone 2 and Zone 3. Model selection was based on Akaike Information Criterion (AIC), R2 values and significant parameter estimates at p < 0.05. The final models for albacore tuna CPUE in all three zones incorporated all three independent variables of LOTI, PWI and PDO. From the findings it can be said that the climatic conditions of LOTI, PWI and PDO play significant roles in structuring the stock dynamics of the albacore tuna in the Eastern and Western South Pacific Ocean. It is imperative to take these factors into account when making management decisions for albacore tuna in these areas.

Influence of Climatic Conditions on the Time Series Fluctuation of Yellowfin Tuna &amp;lt;i&amp;gt;Thunnus albacares&amp;lt;/i&amp;gt; in the South Pacific Ocean

Yellowfin tuna (Thunnus albacares) is one of the most commercially important fish species for South Pacific island nations and territories and for effective conservation efforts it is important to understand the factors which affect its time series pattern. Our research was aimed at elucidating the climatic factors which affected the trajectory of the yellowfin tuna stock in the Eastern and Western South Pacific Ocean. We utilized various climatic factors for the years t - n with n = 0, 1, ..., 8 and investigated their statistical relationship with the catch per unit effort (CPUE) of yellowfin tuna stock from 1957-2008 for three South Pacific zones ranging from the East to the West Pacific Ocean within the coverage area of the Western and Central Pacific Convention Area. Results showed that the climatic conditions of: (i) the global mean land and ocean temperature index (LOTI), (ii) the Pacific warm pool index (PWI) and (iii) Southern Oscillation Index (SOI) had significant relationship with the CPUE of yellowfin tuna in all three zones. LOTI, PWI and SOI were used as independent variables and fitted through modeling to replicate the CPUE trajectory of the yellowfin tuna in Zone 1, Zone 2 and Zone 3. Model selection was based on significant parameter estimates (p < 0.05), Akaikes Information Criterion (AIC) and R2 values. Models selected for all three zones had LOTI, PWI and SOI as the independent variables. This study shows that LOTI, PWI and SOI are climatic conditions which have significant impact on the fluctuation pattern of the yellowfin tuna CPUE in the Eastern and Western South Pacific Ocean. From the findings of this study it can be recommended that when management decisions are made for yellowfin tuna fishery conservation and sustainability in the Eastern and Western South Pacific, it is imperative to take the effect of climatic factors into account.

Twenty-one new records of fish species (Teleostei) from the New Caledonian EEZ (south-western Pacific Ocean)

New records of fish species are reported from New Caledonia, includingPolyipnus aquavitusBaird, 1971 (Sternoptychidae),Porogadus melampeplus(Alcock, 1896) (Ophidiidae),Hoplichthys citrinusGilbert 1905 (Hoplichthyidae),Plectrogenium nanumGilbert 1905 (Plectrogeniidae),Lioscorpius trifasciatusLast, Yearsley &amp;amp; Motomura 2005 (Setarchidae),Neomerinthe megalepisFowler 1938 andPhenacoscorpius megalopsFowler 1938 (Scorpaenidae),Ocosia apiaPoss &amp;amp; Eschmeyer, 1975 (Tetrarogidae),Hoplostethus atlanticusCollett 1889 (Trachichthyidae),Zenion longipinnisKotthaus, 1970 (Zeniontidae),Plectranthias forestiFourmanoir 1977,Plectranthias pelicieriRandall &amp;amp; Shimizu, 1994,Plectranthias rubrifasciatusFourmanoir &amp;amp; Randall, 1979 andRabaulichthys squireiRandall &amp;amp; Walsh, 2010 (Serranidae),Synagrops philippinensis(Günther 1880) (Acropomatidae),Stegastes insularisAllen &amp;amp; Emery 1995 (Pomacentridae),Cirrhilabrus rubrimarginatusRandall 1992 (Labridae),Pteropsaron neocaledonicus Fourmanoir &amp;amp; Rivaton, 1979 (Percophidae),Centrodraco ornatus(Fourmanoir &amp;amp; Rivaton, 1979) andDraconetta xenicaJordan &amp;amp; Fowler 1903 (Draconettidae), andAcanthurus maculiceps(Ahl 1923) (Acanthuridae). A record ofPlectropomus maculatus(Bloch 1790) (Serranidae) from Grande Terre, New Caledonia is confirmed. This paper also includes new depth records ofZenion longipinnis, Plectranthias rubrifasciatus, Synagrops philippinensis, Centrodraco ornatusandDraconetta xenica.

Statistical modeling of Southern Ocean marine diatom proxy and winter sea ice data: Model comparison and developments

We compare the performance of the modern analog technique (MAT), the Imbrie and Kipp transfer function (IKTF), the generalized additive model (GAM) and weighted averaging partial least squares (WA PLS) on a southern hemisphere diatom relative abundance and winter sea ice concentration training data set. All relevant model assumptions are tested with a random 10-fold cross-validation, whilst a hold out cross-validation tested the explanatory power of each model on spatially independent validation data. We used auto correlograms on model residuals, variance partitioning, and principal coordinates analysis of neighbor matrices (PCNM) to investigate the importance of the spatial structure of our training database. A set of hierarchical logistic regression models (or Huisman–Olff–Fresco models) are used to infer the response of each diatom species along the winter sea ice gradient. Our analyses suggest that IKTF is an inappropriate sea ice estimation approach as its underlying statistical assumptions do not hold and the fit of IKTF to our data under cross-validation was poor. We conclude that MAT may be biased by spatial autocorrelation, and together with IKTF fails to provide unbiased estimates of winter sea ice. We find GAM and WA PLS are more appropriate than IKTF and MAT for the estimation of paleo winter sea ice cover throughout the Southern Ocean. However, as WA PLS is based on a unimodal species response, which is rarely exhibited by diatoms along the winter sea ice gradient, we ultimately advocate the application of GAM. GAM only uses diatoms with a statistically significant association, and ecologically based link, with sea ice. GAM outperformed all other models under cross-validation in terms of performance statistics, the fit of GAM to the training dataset and diagnostic tests for model assumptions. We also demonstrate that GAM provides a more detailed and potentially more accurate (based on a comparison with New Zealand and southeast Australian paleo climatic records) paleo winter sea ice record for the southwestern Pacific Ocean in comparison with IKTF, MAT and WA PLS.

Associations between Malnutrition and Climate Variability in Papua New Guinea

Malnutrition is one of the significant health problems in parts of Papua New Guinea (PNG). PNG is located in the southwestern Pacific Ocean and has vulnerable environment from climate change. Malnu...

Squirrels from the Mariana Islands (south-western Pacific) in the Naturalis Biodiversity Center, Leiden, with notes on the mammalian fauna of this Micronesian archipelago

Two mounted skins of squirrels allegedly originating from the Mariana islands, Micronesia (south western Pacific Ocean) are held in the collections of the Naturalis Biodiversity Center, Leiden. They may have been collected in the course of a French scientific expedition, commanded by Louis-Claude De Saulses de Freycinet, in 1819. This paper discusses the identifies of the two specimens, their place in the list of mammals recorded from the Mariana Islands, and reflects on the origins of the Mariana Islands' mammalian fauna.

Description of a new deep-sea eelpout Pachycara matallanasi sp. nov. from the Solomon Sea (western South Pacific Ocean)

A new species of zoarcid fish, Pachycara matallanasi, is described. During the Danish Galathea 3 expedition, on 28 December 2006, six specimens of Pachycara Zugmayer, 1911 were collected from depths of 4350–4450 m. The new species is the second member of the genus in the western South Pacific Ocean. Pachycara matallanasi sp. nov. can be distinguished from its congeners by a combination of the following characters: body without scales; pelvic fin absent; lateral line mediolateral; dorsal fin origin associated with vertebrae 5–6 with 0–1 free predorsal pterygiophores; total vertebrae 103–108; smooth ceratohyal–epihyal articulation; post-temporal with well-developed ventral ramus; coracoid with a posterior strut and a small foramen.http://zoobank.org/urn:lsid:zoobank.org:pub:B61D0421-8CF3-46E5-BCE0-20E12E3ED69A

Global Stochastic Tropical Cyclone Model Based on Principal Component Analysis and Cluster Analysis

AbstractA global stochastic tropical cyclone model was developed as a means for preparing a large number of artificial tropical cyclone (TC) samples with different values for parameters such as track, minimum sea level pressure, and translation speed. In this paper, the model and the results of its verification are presented in detail. The proposed stochastic model is sensitive to approximations of the joint probability distribution functions (PDFs) of TC parameters and temporal correlations. A newly introduced accurate method for approximating joint PDFs by using principal component analysis and cluster analysis resulted in improved reproducibility of TC parameters. The simulation results were compared with historical observational data from the northwestern Pacific, southwestern Pacific, and North Atlantic Oceans. The grid-averaged mean values and distribution patterns of PDFs of TC parameters were in agreement with observational data.