Y-chromosome-Specific STR haplotype data on the Rapanui population (Easter Island)

Located in the south Pacific Ocean, Rapanui is one of the most isolated inhabited islands in the world. Cultural and biological data suggest that the initial Rapanui population originated from central Polynesia, although the presence of foreign or exotic genes in the contemporary population, as a result of admixture with Europeans and/or South Americans during the last two centuries, also has to be considered. To estimate the genetic affinities of the Rapanui population with neighboring populations, we analyzed seven microsatellite polymorphisms of the Y chromosome that recently have been indicated as useful in the study of local population structure and recent demographic history. Phylogenetic analysis of Rapanui Y-chromosome haplotypes identified two clusters. The largest cluster contained 60% of all haplotypes and is characterized, in particular, by the presence of the DYS19*16, DYS390*20, and DYS393*14 alleles, a combination found frequently in Western Samoa. The second cluster is characterized by the presence of the DYS19*14, DYS390*24, and DYS393*13 alleles, and these have a relatively high frequency in European and European-derived populations but are either infrequent or absent in native Pacific populations. In addition to the two clusters, one male is of haplogroup Q*, which is indicative of native American ancestry. The genetic structure of the current male population of Rapanui is most likely a product of some genetic contribution from European and South American invaders who mated with the indigenous Polynesian women. However, analysis of Rapanui's relationships with other Pacific and Asian populations indicates that, as in Western Samoa and Samoa, the population has experienced extreme drift and founder events.     

Molecular genetic evidence for the human settlement of the Pacific: analysis of mitochondrial DNA, Y chromosome and HLA markers

Present-day Pacific islanders are thought to be the descendants of Neolithic agriculturalists who expanded from island South-east Asia several thousand years ago. They speak languages belonging to the Austronesian language family, spoken today in an area spanning half of the circumference of the world, from Madagascar to Easter Island, and from Taiwan to New Zealand. To investigate the genetic affinities of the Austronesian-speaking peoples, we analysed mitochondrial DNA, HLA and Y-chromosome polymorphisms in individuals from eight geographical locations in Asia and the Pacific (China, Taiwan, Java, New Guinea highlands, New Guinea coast, Trobriand Islands, New Britain and Western Samoa). Our results show that the demographic expansion of the Austronesians has left a genetic footprint. However, there is no simple correlation between languages and genes in the Pacific.     

An extinct species of tooth-billed pigeon (Didunculus) from the Kingdom of Tonga, and the concept of endemism in insular landbirds

The tooth-billed pigeon Didunculus strigirostris lives on three islands in Western (Independent) Samoa. A larger, extinct species, Didunculus placopedetes , is described from bones recovered in late Quaternary cave deposits on 'Eua, Kingdom of Tonga. Also referred to D. placopedetes are bones from archaeological sites on the larger Tongan island of Tongatapu and the smaller, lower islands of Lifuka, Ha'ano, 'Uiha and Ha'afeva. As with so many other landbirds in Polynesia, the extinction of D. placopedetes occurred since the arrival of people and presumably was due to human impact. The peopling of Tonga is why the genus Didunculus is considered to be endemic to Samoa. The biogeographic implications of the new data on Didunculus are not unique; human activities have reduced or eliminated the natural range of nearly every genus and species group of Polynesian landbird. The reduced ranges of surviving taxa have created a situation (herein called 'pseudo-endemism') where a taxon that seems today to be endemic to a restricted area (often one or two islands) was much more widespread at first human arrival. As the prehistoric record of insular birds improves in the Pacific and elsewhere, the list of pseudo-endemic taxa will continue to grow.     

Pacific Islanders—Migration and Health

Native Hawaiians and peoples from American Samoa, Guam and the Trust Territories of the Pacific Islands are all recipients of US subsidized health care. Categorized as Pacific Islanders they are a heterogeneous group with differences in biology, cultural adaptation to varied ecological settings, historical influences resulting from colonialism and present-day political factionalism. Yet, westernization on home islands and migration to Hawaii and the western United States have created similarities in disease patterns among these culturally diverse peoples. They have high rates of the chronic diseases of civilization: cardiovascular disease, diabetes mellitus and hypertension. Obesity, associated with these ailments, has become a major health problem among Pacific Islanders and may be attributed to changes in local food production and consumption in conjunction with sedentarization. Culturally and linguistically distinct from the American mainstream, these people as migrants or residents are marginal within the US social structure and find if difficult to obtain adequate medical treatment.     

Lactose malabsorption in Polynesian and white children in the south west Pacific studied by breath hydrogen technique.

Lactose malabsorption was studied by a breath hydrogen technique in 139 Samoan and 68 white schoolchildren. The Samoans were studied in four locations, two in Western Samoa and two in New Zealand, and the white children in both the Cook Islands and New Zealand. The prevalence of malabsorption varied with location: for Samoans it ranged from 41% to 60% in Western Samoa and 0% to 35% in New Zealand; white children had rates of 27% in the Cook Islands and 5% in New Zealand. Environmental factors rather than genetic factors are likely to play the main part in initiating if not perpetuating lactose malabsorption. In both races lactose malabsorption had no effect on the acceptance of, consumption of, and number of gastrointestinal symptoms caused by milk and milk biscuits. Children who had symptoms after consuming a particular dairy product were more likely to say they disliked it than those who reported no symptoms.     

Cordyline ovens (Umu Ti) in Samoa

In ancient Samoa,Cordyline roots were prepared for use as a candy and a sweetening agent by baking in large buried stone ovens for several days. In a modern attempt to duplicate this ancient technology,Cordyline terminalis roots collected in the mountains of Upolu, Western Samoa, were baked in both a modern propane oven and in an oven orumu prepared in the traditional manner. The success of this attempt is described, together with its significance for ethnobotanical and archaeological studies in Samoa.     

The distribution,abundance and ecology of the blue coral Heliopora coerulea (Pallas) in the Pacific

Heliopora coerulea (Alcyonaria, Coenothecalia), widespread since the Cretaceous, is today found in the Indo-Western Pacific between 25° N and 25° S but is uncommon throughout most of its range. Studies around its reported southern and eastern limits of distribution (Great Barrier Reef, Vanuatu, Fiji, Tonga, Western Samoa, Tuvalu, Gilbert Group) suggest that ocean temperature (a lower marginal isotherm of 22°C), duration of larval life-span, prevailing currents, and the geological and climatic history of isolated archipelagoes determine distribution. Heliopora was found to be far more abundant in the equatorial Central Pacific sites (Tuvalu and Gilbert growps) than in the Western Pacific (Great Barrier Reef, New Guinea, Solomon Islands, Ponape, Palau). Heliopora comprised up to 16% of beach sediments in Tuvalu atolls, and was the dominant coral (averaging 40% of substrate between 6 m and 10 m on reef slopes) in coral assemblages on Tarawa Atoll. From ecological studies in Tarawa it is suggested that competition from the more specialized and aggressive Scleractinia (particularly Acroporidae and Faviidae) is the major factor limiting abundance in the equatorial Western Pacific.     

Identity,activity, and the well-being of adolescents and youths: lessons from young people in a Micronesian society

Comparative studies of the health, well-being, and social functioning of adolescents and youths have, in the past two decades, been focused on young people in developing countries where rapid social, cultural, and economic changes have been associated with dramatic increases in the rates of social problems indicative of poorer mental health. Young people in many Pacific Island societies suffer from some of the highest rates of social problems like suicide and substance abuse in the world. It is generally agreed that the increases in rates of social problems among youths in this region result from increases in psychosocial stress, anger, and frustration surrounding intergenerational conflict within the family. Much less is known about the aspects of everyday experiences of young people in the Pacific that can lead to psychosocial stress and the angry episodes of interpersonal conflict that often precede suicide attempts and binge drinking. This paper examines 40 cases of interpersonal conflict in young men's and women's experiences in the islands of Chuuk of the Federated States of Micronesia to better understand what can lead to elevated levels of psychosocial stress for youths in the Pacific. This study shows that the emotional crises of young people in Chuuk often emerge from the incongruence in their pursuit of valued personal and social identities within the family, the community, and the peer group. Thus youths who experience more incongruity in their engagements across the multiple activity settings of everyday life are at greater risk for stressful experiences.     

Cladogenesis as the result of long-distance rafting events in South Pacific topshells (Gastropoda, Trochidae)

We used DNA sequences of lecithotrophic monodontine topshells, belonging to the genera Diloma, Melagraphia, and Austrocochlea, to ascertain how this group became established over a large area of the South Pacific Ocean. The phylogeny of the topshells was estimated using portions of two mitochondrial genes (16S and cytochrome oxidase 1) and one nuclear gene (actin). A range of divergence rates was used to estimate the approximate timing of cladogenetic events within their phylogenetic tree. These estimates allow us to unambiguously reject vicariant explanations for several major divergence events and to infer several dispersal events across wide stretches of ocean. The first were two initial dispersal events from Australia (1) to an area between Samoa and Japan and (2) to New Zealand. Subsequently, at least one, and possibly two, recent eastward dispersals took place from New Zealand to Chile and the Juan Fernandez Islands, and one further dispersal occurred from somewhere in the tropical Pacific to Samoa. Moreover, owing to the short-lived nature of the topshell larvae, transoceanic larval dispersal is unlikely. The apparent paradox of a short larval phase and broad geographic range suggests that dispersal most probably occurred by rafting of adults on a suitable platform such as macroalgae; indeed, naturally buoyant bull kelp is the natural habitat of the most geographically widespread species in this group. Our molecular phylogenies imply that, despite of being an unlikely event, adult rafting in ocean currents has occurred on several occasions throughout the evolutionary history of topshells, resulting in their wide present-day distribution.     

Supply chain and marketing of sea grapes,Caulerpa racemosa (Forsskål) J. Agardh (Chlorophyta: Caulerpaceae) in Fiji,Samoa and Tonga

This report describes for the first time the supply chain of Caulerpa racemosa in three Pacific Island countries. The harvesting and marketing of C. racemosa are important subsistence activities for villagers in Fiji and Samoa, less so in Tonga. At least 150 harvesters are involved in Fiji, some 100 in Samoa and only a handful in Tonga. The annual combined crop is of some 123 t valued at around US$266,492. In Fiji, it is projected that supply does not meet local demand and there is a potential export market that is currently operating at a pilot project level. In Samoa, the supply is considered adequate for the current market. In Tonga, harvesting is carried out by a few families and supplies a niche market in that country. The possibilities of field cultivation of Caulerpa have been explored but, at present, with only limited success in Samoa. The supply chain is simple in all three countries, and only in Fiji are middlemen involved in the distribution process. The limitations for marketing include the fact that only a few sites supply most of the crop in all the three countries, that all sites need to be conserved through sustainable harvesting methods, the short shelf life of the crop and a lack of information on the carrying capacity of harvest sites. Caulerpa remains a crop that fulfils a niche market but has the potential to be scaled up for additional livelihood development in the future.     

Sulfated flavonoids and leaf morphology of the Halophila ovalis—H. minor complex (hydrocharitaceae) in the Pacific Islands and Australia

Sulfated flavonoids showed a systematic pattern among Halophila populations of the Pacific and Australia. Large-leaved plants, typical of H. ovalis (R.Br.) Hook. f., in the Palau Islands (Belau) and in Australia contained sulfated flavonoids, but small-leaved plants that have received various treatments under H. ovalis, including ssp. bullosa (Setchell) den Hartog and ssp. hawaiiana (Doty & Stone) den Hartog, and under H. minor (Zoll.) den Hartog or H. ovata Gaud. in American Samoa, Western Samoa, Tonga, Fiji, Wallis I., New Caledonia, Yap, Guam, Hawaii and Australia lacked sulfated flavonoids. Plants collected in their natural habitats as well as those grown in experimental cultures showed the characteristic patterns of these secondary compounds. Although the large-leaved plants have the potential for producing the largest leaves in the complex, they are not separable from small-leaved plants in leaf dimensions or in number of pairs of cross veins under all environmental conditions. The production of sulfated flavonoids and the potential for greater leaf length are the characteristics that can be used to separate typical H. ovalis and ssp. australis (Doty & Stone) den Hartog from other members of the complex.     

The species of Pareromene Osthelder (Pyralidae: Crambinae: Diptychophorini) from the western South Pacific,with further notes on the New Zealand species

Six species of Crambinae described by Meyrick, and three by Tarns, from western South Pacific islands between the Louisiade Archipelago and Samoa, are redescribed and transferred from Diptychophora Zeller to Pareromene Osthelder. Five new species and one new subspecies of Pareromene are described. The zoogeography and phylogeny of the genus in this region are briefly described, and some additional notes on New Zealand species are given.     

Crustose coralline algal diseases in the U.S.-Affiliated Pacific Islands

Despite the critical role of crustose coralline algae (CCA) in coral reef formation, maintenance, and ecology, little is known about coralline algal disease abundance, distribution, etiology, or the potential implications of declining CCA flora. This paper presents the first quantitative study of CCA disease on U.S. Pacific coral reefs, based on Rapid Ecological Assessments conducted at 337 discrete sites, at 42 different U.S.-Affiliated Pacific Islands and Atolls, within 5 major geographical regions: main Hawaiian Islands, Northwestern Hawaiian Islands, American Samoa, the Pacific Remote Island Areas (PRIA), and Guam and the Commonwealth of the Northern Mariana Islands (CNMI). Five major disease categories were enumerated, and a disease occurrence index was estimated, based on case counts relative to percent CCA cover. CCA disease occurrence exhibited considerable spatial variability both between and within islands/atolls, with some regions being disproportionately affected by disease. No diseases were observed at remote Johnston and Wake Atolls, or the main Hawaiian Islands. Diseases were rare in the Northwestern Hawaiian Islands and the Northern Mariana Islands; occasional to common around the PRIA, and common to abundant in American Samoa, Guam, and the Southern Mariana Islands. Pacific-wide, disease occurrence was statistically associated with CCA percent cover and sea surface temperatures (SSTs) but not with human population density; nonetheless, disease occurrence and population density were statistically correlated for those islands containing disease. Although Pacific-wide, the occurrence of disease was low, with no active outbreaks detected in any region, hot spots of disease were detected around Guam, the southern CNMI, American Samoa, and the PRIA. The high levels of spatial and temporal variability in disease occurrence herein underscore the patchy nature and fluctuating distribution dynamics of these afflictions. Also, the widespread dispersal capabilities and extraordinary infective properties of some of these pathogens highlight the importance of better understanding CCA disease dynamics and discerning the relative threat levels on coral reef ecosystems.     

The Genetic Structure of Staphylococcus aureus Populations from the Southwest Pacific

The genetic structure of Staphylococcus aureus populations sampled from diverse regions of the globe have been the subject of numerous investigations. Here we describe the structure of S. aureus populations collected from the Southwest Pacific. Multi-locus sequence typing was performed on 467 isolates obtained from people with nasal colonization or bacteremia in Auckland (NZ), and patients predominantly affected by skin and soft tissue infection in Samoa, Fiji and Tonga. The predominant sequence types (STs) varied between Auckland (ST5), Fiji (ST30), and Samoa (ST1), however, the overall genetic diversity within each region did not differ significantly between locations. Divergent Clonal Complex 75 (CC75) strains were isolated in Auckland and Fiji. When diversity of the Southwest Pacific populations was compared with those previously described from Asia, Europe, North America and Africa no significant differences were detected. With the exception of CC75 strains, the global collection of S. aureus encompasses relatively little diversity, with novel STs arising locally from a small number of widespread lineages.     

The epizootiology of two pathogens of the coconut palm rhinoceros beetle

Two diseases of Oryctes rhinoceros caused by Metarrhizium anisopliae and a virus were introduced from Western Samoa into Tongatapu, Kingdom of Tonga, in 1969 and 1970, respectively. The fungus remained at a low incidence and did not significantly affect the beetle population. The virus disease developed to epizootic levels within 5 months and spread across the island in 15 months. The beetle population was monitored through palm damage surveys, which confirmed that the population was considerably reduced by the disease.The greater impact of the virus was attributed to its much higher power of dispersal through infected beetles.The experiment supports the view that the reduction in beetle numbers recorded previously in Western Samoa was caused by a virus epizootic.     

Human,Oceanographic and Habitat Drivers of Central and Western Pacific Coral Reef Fish Assemblages

Coral reefs around US- and US-affiliated Pacific islands and atolls span wide oceanographic gradients and levels of human impact. Here we examine the relative influence of these factors on coral reef fish biomass, using data from a consistent large-scale ecosystem monitoring program conducted by scientific divers over the course of >2,000 hours of underwater observation at 1,934 sites, across ~40 islands and atolls. Consistent with previous smaller-scale studies, our results show sharp declines in reef fish biomass at relatively low human population density, followed by more gradual declines as human population density increased further. Adjusting for other factors, the highest levels of oceanic productivity among our study locations were associated with more than double the biomass of reef fishes (including ~4 times the biomass of planktivores and piscivores) compared to islands with lowest oceanic productivity. Our results emphasize that coral reef areas do not all have equal ability to sustain large reef fish stocks, and that what is natural varies significantly amongst locations. Comparisons of biomass estimates derived from visual surveys with predicted biomass in the absence of humans indicated that total reef fish biomass was depleted by 61% to 69% at populated islands in the Mariana Archipelago; by 20% to 78% in the Main Hawaiian islands; and by 21% to 56% in American Samoa.     

Ethnobotany of Tokelau: The plants,their Tokelau names,and their uses

Three research trips were made to the Tokelau Islands (including Swains Island), located north of Samoa in Western Polynesia, and a collection of the flora of the islands was made. At the same time, Tokelauan informants were interviewed about native names and uses of plants found there. This information was augmented by a literature review, by data on plant specimens stored at the Bernice P. Bishop Museum, and by interviews with other Tokelauans now living in Samoa. From this information, an account of Tokelauan plant names and their ethnobotanical uses was compiled.     

The uses ofAtuna racemosa Raf. (Chrysobalanaceae) in Samoa

The Uses of Atuna racemosaRaf. (Chrysobalanaceae) in Samoa. Economic Botany 58(3):470-475, 2004. An ethnobotanical study was made of the uses ofAtuna racemosa subsp.racemosa (Chrysobalanaceae) in Samoa. The main use is of the cotyledons to extract an anti-inflammatory massage oil and a putty to caulk boats. Minor uses as a medicinal and of the wood are reported and a survey of herbarium material shows that the fruit of Atuna is widely used throughout the Pacific region.     

Comparative Analysis of Japanese Three-Spined Stickleback Clades Reveals the Pacific Ocean Lineage Has Adapted to Freshwater Environments while the Japan Sea Has Not

Divergent selection and adaptive divergence can increase phenotypic diversification amongst populations and lineages. Yet adaptive divergence between different environments, habitats or niches does not occur in all lineages. For example, the colonization of freshwater environments by ancestral marine species has triggered adaptive radiation and phenotypic diversification in some taxa but not in others. Studying closely related lineages differing in their ability to diversify is an excellent means of understanding the factors promoting and constraining adaptive evolution. A well-known example of the evolution of increased phenotypic diversification following freshwater colonization is the three-spined stickleback. Two closely related stickleback lineages, the Pacific Ocean and the Japan Sea occur in Japan. However, Japanese freshwater stickleback populations are derived from the Pacific Ocean lineage only, suggesting the Japan Sea lineage is unable to colonize freshwater. Using stable isotope data and trophic morphology, we first show higher rates of phenotypic and ecological diversification between marine and freshwater populations within the Pacific Ocean lineage, confirming adaptive divergence has occurred between the two lineages and within the Pacific Ocean lineage but not in the Japan Sea lineage. We further identified consistent divergence in diet and foraging behaviour between marine forms from each lineage, confirming Pacific Ocean marine sticklebacks, from which all Japanese freshwater populations are derived, are better adapted to freshwater environments than Japan Sea sticklebacks. We suggest adaptive divergence between ancestral marine populations may have played a role in constraining phenotypic diversification and adaptive evolution in Japanese sticklebacks.