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1.
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.  相似文献   

2.
The wetlands of 21 countries and territories of the Pacific Islands region are reviewed: American Samoa, Cook Islands, Federated States of Micronesia, Fiji, French Polynesia, Guam, Kiribati, Marshall Islands, Nauru, New Caledonia, Niue, Northern Mariana Islands, Palau, Papua New Guinea, Samoa, Solomon Islands, Tokelau, Tonga, Tuvalu, Vanuatu, and Wallis and Futuna. The regions’ wetlands are classified into seven systems: coral reefs, seagrass beds, mangrove swamps, riverine, lacustrine, freshwater swamp forests and marshes. The diversity of species in each of these groups is at near global maxima at the west of the region, with decline towards the east with increasing isolation, and decreasing island size and age. The community structure is unique in each country, and many have endemic species with the habitat isolation that epitomises this island region. There remain, however, some serious gaps in basic inventory, particularly in freshwater biodiversity. Threats to wetlands include introduced freshwater species, loss of wetlands adjacent to urban growth, downstream effects of mining and land clearance, and over-use of mangrove, seagrass and coral reef resources by predominant subsistence economies that remain in this region. Only five countries are signatories to the Ramsar convention on wetlands, and this only recently with seven sites. Wetland managers have identified the need for community education, baseline surveys and monitoring, better legislation and policy for wetland management, and improved capacity of local communities to allow the wise use of their wetlands.  相似文献   

3.
Efforts to map coral reef ecosystems in the Hawaiian Archipelago using optical imagery have revealed the presence of numerous scleractinian, zoothanthellate coral reefs at depths of 30–130+ m, most of which were previously undiscovered. Such coral reefs and their associated communities have been recently defined as mesophotic coral ecosystems (MCEs). Several types of MCEs are found in Hawai‘i, each of which dominates a different depth range and is characterized by a unique pattern of coral community structure and colony morphology. Although MCEs are documented near both ends of the archipelago and on many of the islands in between, the maximum depth and prevalence of MCEs in Hawai‘i were found to decline with increasing latitude. The Main Hawaiian Islands (MHI) had significantly deeper and greater percentages of scleractinian coral, and peaks in cover of both scleractinian corals and macroalgae occurred within depth bins 20 m deeper than in the Northwestern Hawaiian Islands (NWHI). Across the archipelago, as depth increased the combined percentage of living cover of mega benthic taxa declined sharply with increasing depth below 70 m, despite the widespread availability of hard substrate.  相似文献   

4.
Benthic cyanobacteria can respond rapidly to favorable environmental conditions, overgrow a variety of reef organisms, and dominate benthic marine communities; however, little is known about the dynamics and consequences of such cyanobacterial blooms in coral reef ecosystems. In this study, the benthic community was quantified at the time of coral spawnings in Guam to assess the substrate that coral larvae would encounter when attempting settlement. Transects at 9, 18, and 25-m depths were surveyed at two reef sites before and after heavy wave action driven by westerly monsoon winds. Communities differed significantly between sites and depths, but major changes in benthic community structure were associated with wave action driven by monsoon winds. A shift from cyanobacteria to crustose coralline algae (CCA) accounted for 44% of this change. Coral recruitment on Guam may be limited by substrate availability if cyanobacteria cover large areas of the reef at the time of settlement, and consequently recruitment may in part depend upon wave action from annual monsoon winds and tropical storms which remove cyanobacteria, thereby exposing underlying CCA and other substrate suitable for coral settlement.  相似文献   

5.
Polychaetes collected from coral reefs and other coastal habitats on Guam and Saipan, and information from published studies bring the known number of species from these two islands to 101 and 15, respectively. Sediment and rock dwelling species collected, and those previously recorded, belong to 25 families. Polychaete assemblages are compared on the basis of species richness, genera in common, and trophic categories, with other West Pacific, Hawaiian and East Indian Ocean locations. Polychaetes from Guam are similar to those on reef flats of Hawaii, Enewetak, and Indonesia in faunal composition and density. Despite the limitations in comparable collecting effort and quantitative analyses for some of the areas, these coral reefs have similar complements of families and genera present, and proportions of four trophic categories.  相似文献   

6.
Volcanically active islands abound in the tropical Pacific and harbor complex coral communities. Whereas lava streams and deep ash deposits are well-known to devastate coral communities through burial and smothering, little is known about the effect of moderate amounts of small particulate ash deposits on reef communities. Volcanic ash contains a diversity of chemical compounds that can induce nutrient enrichments triggering changes in benthic composition. Two independently collected data sets on the marine benthos of the pristine and remote reefs around Pagan Island, Northern Mariana Islands, reveal a sudden critical transition to cyanobacteria-dominated communities in 2009–2010, which coincides with a period of continuous volcanic ash eruptions. Concurrently, localized outbreaks of the coral-killing cyanobacteriosponge Terpios hoshinota displayed a remarkable symbiosis with filamentous cyanobacteria, which supported the rapid overgrowth of massive coral colonies and allowed the sponge to colonize substrate types from which it has not been documented before. The chemical composition of tephra from Pagan indicates that the outbreak of nuisance species on its reefs might represent an early succession stage of iron enrichment (a.k.a. “black reefs”) similar to that caused by anthropogenic debris like ship wrecks or natural events like particulate deposition from wildfire smoke plumes or desert dust storms. Once Pagan''s volcanic activity ceased in 2011, the cyanobacterial bloom disappeared. Another group of well-known nuisance algae in the tropical Pacific, the pelagophytes, did not reach bloom densities during this period of ash eruptions but new species records for the Northern Mariana Islands were documented. These field observations indicate that the study of population dynamics of pristine coral communities can advance our understanding of the resilience of tropical reef systems to natural and anthropogenic disturbances.  相似文献   

7.
Aim To determine if Kōko Seamount submerged below sea level before Kure Island and Pearl and Hermes Reef formed, resulting in a period in which there were no extant islands. A period with no islands would eliminate prior terrestrial and shallow marine biotas that could migrate from island to island and require a restart of colonization from distant shores to populate the younger islands of the Hawaiian volcanic chain. Location Emperor Seamount Chain, north‐central Pacific Ocean. Methods We estimate subsidence rates for Kōko Seamount using ages determined from fossil large foraminifera and Sr‐isotopes, and maximum depths using palaeodepth estimates based on coralline algae. These data are combined with palaeolatitude changes as the Pacific Plate moved northwards, sea level variations, and sea surface temperature variations at the seamount through time to reconstruct the time and causes of submergence. Results Rounded carbonate clasts include three facies: zooxanthelate corals, bioclastic packstones to rudstones, and rhodolith floatstones. Two rudstones contain relatively deep‐water, coralline algal rhodoliths and large foraminifera indicative of Aquitanian (20.4–20 Ma) and Burdigalian (20–16 Ma) stages of the Early Miocene, consistent with Sr‐isotope ages of algae and one sample of large foraminifera. Corals grew on Kōko Seamount from c. 50 to 27.1 ± 0.4 Ma, the youngest Sr‐isotope age of a coral sample. These shallow, warm‐water coral reefs came under increasing stress as the volcano subsided at 0.012 ± 0.003 mm yr?1, and migrated northwards, and as global climate cooled. The summit submerged and shallow coral reef growth ceased before 29 Ma, probably around 33 Ma. The volcano continued its slow subsidence, and deep‐water carbonates accumulated until they too were unable to keep pace, dying out at c. 16 Ma. Main conclusions The final submergence of the summit of Kōko Seamount by about 33 Ma confirms that biota on older Hawaiian–Emperor Islands could not have migrated from island to island along the entire chain to eventually colonize the present Hawaiian Islands. There was a period between at least 33 and 29 Ma in which no islands existed, and distant colonization had to repopulate the younger portion of the Hawaiian chain, which began to emerge between about 29 and 23 Ma.  相似文献   

8.
The Northwestern Hawaiian Islands (NWHI) are considered to be among the most pristine coral reef ecosystems remaining on the planet. These reefs naturally contain a high percent cover of algal functional groups with relatively low coral abundance and exhibit thriving fish communities dominated by top predators. Despite their highly protected status, these reefs are at risk from both direct and indirect anthropogenic sources. This study provides the first comprehensive data on percent coverage of algae, coral, and non-coral invertebrates at the species level, and investigates spatial diversity patterns across the archipelago to document benthic communities before further environmental changes occur in response to global warming and ocean acidification. Monitoring studies show that non-calcified macroalgae cover a greater percentage of substrate than corals on many high latitude reef sites. Forereef habitats in atoll systems often contain high abundances of the green macroalga Microdictyon setchellianum and the brown macroalga Lobophora variegata, yet these organisms were uncommon in forereefs of non-atoll systems. Species of the brown macroalgal genera Padina, Sargassum, and Stypopodium and the red macroalgal genus Laurencia became increasingly common in the two northernmost atolls of the island chain but were uncommon components of more southerly islands. Conversely, the scleractinian coral Porites lobata was common on forereefs at southern islands but less common at northern islands. Currently accepted paradigms of what constitutes a “healthy” reef may not apply to the subtropical NWHI, and metrics used to gauge reef health (e.g., high coral cover) need to be reevaluated.  相似文献   

9.
The immediate effects of pyroclastic deposits (ash fall) on reef communities after volcanic eruptions on remote tropical islands have never been critically examined. This study discusses findings from an interdisciplinary research expedition to the island of Anatahan (Commonwealth of the Northern Mariana Islands), 4 months after its first recorded volcanic eruption. Deep ash completely obliterated any trace of reef communities off the northeastern shores of the island; however, reefs in other areas, although still blanketed with ash deposits, fared better. Mean fish biomass recorded around Anatahan after the eruption was 0.22 kg 100 m−2, a value three times lower than at Sarigan, the closest neighbor island. Similarly, average percent cover of live coral (7.9%), crustose coralline red algal (7.7%), and macroalgal (14.3%) populations was 2.3, 1.4, and 3.0 times lower than at Sarigan, respectively.  相似文献   

10.
We used microsatellite markers to assess the population genetic structure of the scribbled rabbitfish Siganus spinus in the western Pacific. This species is a culturally important food fish in the Mariana Archipelago and subject to high fishing pressure. Our primary hypothesis was to test whether the individuals resident in the southern Mariana Island chain were genetically distinct and hence should be managed as discrete stocks. In addition to spatial sampling of adults, newly‐settled individuals were sampled on Guam over four recruitment events to assess the temporal stability of the observed spatial patterns, and evidence of self‐recruitment. We found significant genetic structure in S. spinus across the western Pacific, with Bayesian analyses revealing three genetically distinct clusters: the southern Mariana Islands, east Micronesia, and the west Pacific; with the southern Mariana Islands being more strongly differentiated from the rest of the region. Analyses of temporal samples from Guam indicated the southern Mariana cluster was stable over time, with no genetic differentiation between adults versus recruits, or between samples collected across four separate recruitment events spanning 11 months. Subsequent assignment tests indicated seven recruits had self‐recruited from within the Southern Mariana Islands population. Our results confirm the relative isolation of the southern Mariana Islands population and highlight how local processes can act to isolate populations that, by virtue of their broad‐scale distribution, have been subject to traditionally high gene flows. Our results add to a growing consensus that self‐recruitment is a highly significant influence on the population dynamics of tropical reef fish.  相似文献   

11.
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.  相似文献   

12.
Diseases threaten the structure and function of marine ecosystems and are contributing to the global decline of coral reefs. We currently lack an understanding of how climate change stressors, such as ocean acidification (OA) and warming, may simultaneously affect coral reef disease dynamics, particularly diseases threatening key reef-building organisms, for example crustose coralline algae (CCA). Here, we use coralline fungal disease (CFD), a previously described CCA disease from the Pacific, to examine these simultaneous effects using both field observations and experimental manipulations. We identify the associated fungus as belonging to the subphylum Ustilaginomycetes and show linear lesion expansion rates on individual hosts can reach 6.5 mm per day. Further, we demonstrate for the first time, to our knowledge, that ocean-warming events could increase the frequency of CFD outbreaks on coral reefs, but that OA-induced lowering of pH may ameliorate outbreaks by slowing lesion expansion rates on individual hosts. Lowered pH may still reduce overall host survivorship, however, by reducing calcification and facilitating fungal bio-erosion. Such complex, interactive effects between simultaneous extrinsic environmental stressors on disease dynamics are important to consider if we are to accurately predict the response of coral reef communities to future climate change.  相似文献   

13.
Coral reefs of US‐held islands in the central Pacific Ocean are among the most pristine in the world and represent over 93% of the reef systems under United States jurisdiction. The remote location of many islands has limited past algal research, resulting in incomplete understanding of species diversity, quantity, and ecology. Starting in 2000, the Coral Reef Ecosystem Investigation (CREI) began rapid ecological assessments on many Pacific island reefs to monitor ecological changes in reef biota over time. During the past year, algal efforts have concentrated on the French Frigate Shoals (Northwestern Hawaiian Islands) where we have increased the number of algal species reported by 1000%. Additionally, species new to science, including Acrosymphyton brainardii and Scinaia huismanii, have been described. Quantitative field sampling using a photoquadrat method is revealing species of the green algae Halimeda and Microdicyton to be ecological dominants in many areas during late summer/early autumn. Preliminary analyses with Primer software show species composition and abundance of all benthic organisms to differ significantly between most field sites sampled. Additional benthic habitat mapping of Pacific island reefs by CREI researchers is breaking the long‐held paradigm that macroalgal cover is minimal in healthy tropical reef systems. Videotape analyses of benthic communities often find over 50% algal cover from 1 to 20 meter depths in many locations. Common ratios of macroalgae, turf algae, and crustose coralline algae to corals, other benthic organisms and substrate types on US Pacific reefs are being calculated for the first time.  相似文献   

14.
About seven families of fishes occur routinely in fresh water on oceanic high islands of the tropical Pacific; others (sharks, jacks, bonefish, etc.) are occasional visitors. However, amphidromous fishes (freshwater adults, marine larvae) of the families Gobiidae and Eleotridae are predominant in island streams. Hawai'i, representing the northernmost extent of Polynesia, has five species of gobioid fishes whose adults are limited to fresh water, but Guam, in the Mariana Islands of the far Western Pacific, has more than four times that number. Hawaiian stream fishes are strikingly similar to their Guamanian relatives in their distribution, ecology, and behavior. At both localities, these fishes typically exhibit strong species specificity in the section of stream inhabited by adults, in the microhabitat selected, and in their food and feeding. Although incompletely understood, aspects of the life cycles of amphidromous island fishes (spawning, migrations into and from the sea, and others) are cued by seasonal and short-term changes in stream flow. In the Hawaiian Islands, water-use decisions based on the imperatives of allowing no net loss of habitat for aquatic animals and maintaining stream-ocean pathways for migrating animals have facilitated both management and conservation of diversity in island streams.  相似文献   

15.
A dearth of scientific data surrounding Micronesia’s coral-reef fisheries has limited their formal assessment and continues to hinder local and regional management efforts. We approach this problem by comparing catch-based datasets from market landings across Micronesia to evaluate fishery status in the Commonwealth of the Northern Mariana Islands (CNMI), Guam, Yap, and Pohnpei. Initial examinations found that calm weather and low lunar illumination predicted between 6% (Yap) and 30% (CNMI) of the variances in daily commercial landings. Both environmentally driven catch success and daily catch variability increased in accordance with reef-fish demand indices. Subsequent insight from species composition and size-at-capture data supported these findings, highlighting reduced trophic levels and capture sizes where higher human-population-per-reef-area existed. Among the 12–15 target species and/or species complexes that accounted for 70% of the harvest biomass, capture sizes were consistently smallest for CNMI and Guam, often below the reported mean reproductive sizes. Comparatively, Pohnpei has the greatest potential for reef fisheries, with a large reef area (303 km2) and a moderate human population (34,000 people). However, the estimated harvest volume of 476 mt year−1 was 8–9 times higher than other jurisdictions. Even on Yap where the reef-fish demand index was lowest (67.7 people km−2 reef habitat), many target fish were harvested below their mean reproductive sizes, including the iconic green bumphead parrotfish and humphead wrasse, as well as several other herbivores. We discuss our results with respect to the contemporary doctrine surrounding size-spectra, catch composition, and catch frequencies that afford insight into fishery pressure and status. We posit that regional catch-based policies (initially) instituted at the market level, combined with area and gear-based restrictions, represent plausible vectors for improving Micronesian fisheries.  相似文献   

16.
BackgroundCervical cancer incidence in the US-Affiliated Pacific Islands (USAPIs) is double that of the US mainland. American Samoa, Commonwealth of Northern Mariana Islands (CNMI), Guam and the Republic of Palau receive funding from the Centers for Disease Control (CDC) National Breast and Cervical Cancer Early Detection Program (NBCCEDP) to implement cervical cancer screening to low-income, uninsured or under insured women. The USAPI grantees report data on screening and follow-up activities to the CDC.Materials and methodsWe examined cervical cancer screening and follow-up data from the NBCCEDP programs in the four USAPIs from 2007 to 2015. We summarized screening done by Papanicolaou (Pap) and oncogenic human papillomavirus (HPV) tests, follow-up and diagnostic tests provided, and histology results observed.ResultsA total of 22,249 Pap tests were conducted in 14,206 women in the four USAPIs programs from 2007–2015. The overall percentages of abnormal Pap results (low-grade squamous intraepithelial lesions or worse) was 2.4% for first program screens and 1.8% for subsequent program screens. Histology results showed a high proportion of cervical intraepithelial neoplasia grade 2 or worse (57%) among women with precancers and cancers. Roughly one-third (32%) of Pap test results warranting follow-up had no data recorded on diagnostic tests or follow-up done.ConclusionThis is the first report of cervical cancer screening and outcomes of women served in the USAPI through the NBCCEDP with similar results for abnormal Pap tests, but higher proportion of precancers and cancers, when compared to national NBCCEDP data. The USAPI face significant challenges in implementing cervical cancer screening, particularly in providing and recording data on diagnostic tests and follow-up. The screening programs in the USAPI should further examine specific barriers to follow-up of women with abnormal Pap results and possible solutions to address them.  相似文献   

17.
The effects of substratum on the growth of Terpios was demonstrated using experimental and observational data at Guam, Mariana Islands. Terpios growth was measured on live coral, reef rock, and red calcareous algae in the field. In addition, Terpios was transplanted onto live coral, air-blasted (clean) coral, reef rock, and plexiglass plates, and subsequent growth measured. Terpios grows fastest on clean substrata followed by live coral, reef rock and red calcareous algae in decreasing order. Terpios is sometimes overgrown by Montipora, Porites and red calcareous algae. Since Terpios grows fastest when living coral tissue is removed, it is not likely that Terpios ingests coral tissue as previously suggested in the literature. Instead, Terpios is probably an efficient competitor of corals for space. Terpios overgrows most hard, stable reef substrata, and the growth rate on all sample substrata is substantial. Therefore Terpios has a great potential for covering a reef and may be one of the most important causes of disturbance on some coral reefs.Contribution no. 206 from the University of Guam Marine Laboratory  相似文献   

18.
Howland and Baker Islands are two small, isolated reef and sand islets located near the equator in the central Pacific Ocean that are situated approximately 60 km apart. In 2004 and 2006, species-level monitoring at multiple sites, coupled with towed-diver surveys in 2002, 2004, and 2006 on both of these federally protected islands, revealed diverse fish, coral, macroinvertebrate, and algal assemblages. This study examines inter- and intra-island spatial and temporal differences in community composition among sites and presents baseline biological community parameters for two of the least impacted reef systems in the world. Despite similarities in species composition, permutational multivariate analysis of variance (PERMANOVA) and multidimensional scaling ordinations (nMDS) suggest biological communities at the two islands are distinct with Baker Island containing a greater percent cover of branched Acroporid corals and turf algae and Howland Island containing a greater percent cover of crustose coralline red algae and small, compact genera of coral. Both islands also contained considerable cover of non-invasive macroalgae. PERMANOVA further revealed benthic and fish species composition to differ between forereef and reef shelf sites from different sides of each island. When islands were considered as a whole, temporal changes were not noted between 2004 and 2006; however, temporal changes at select sites did occur, with coral cover decreasing significantly along the west side of Baker Island from 2004 to 2006.  相似文献   

19.
On coral reefs in Palmyra—a central Pacific atoll with limited fishing pressure—total fish biomass was 428 and 299% greater than on reefs in nearby Christmas and Fanning Islands. Large apex predators, groupers, sharks, snappers, and jacks larger than 50 cm in length, accounted for 56% of total fish biomass in Palmyra on average, but only 7 and 3% on Christmas and Fanning. These biomass proportions are remarkably similar to those previously reported for the remote and uninhabited Northwest Hawaiian Islands (NWHI) and densely populated Main Hawaiian Islands (MHI), although Palmyra’s reefs are dominated in biomass by sharks (44% of the total), whereas the NWHI by jacks (39%). Herbivorous fish biomass was also greater on Palmyra than on Christmas and Fanning (343 and 207%, respectively). These results and previous findings indicate that remote, uninhabited islands support high levels of consumers, and highlight the importance of healthy coral reef ecosystems as reference points for assessment of human impacts and establishment of restoration goals.  相似文献   

20.
BackgroundPacific island countries and territories (PICTs) comprise 20,000–30,000 islands in the Pacific Ocean. PICTs face challenges in relation to small population sizes, geographic dispersion, increasing adoption of unhealthy life-styles and the burden of both communicable and non-communicable diseases, including cancer. This study reviews data on cancer incidence and mortality in the PICTs, with special focus on indigenous populations.MethodsPICTs with populations of <1.5 million (‘small nations’) were included in this study. Information on cancer incidence and mortality was extracted from the GLOBOCAN 2012 database. Scientific and grey literature was narratively reviewed for publications published after 2000.ResultsOf the 21 PICTs, seven countries were included in the GLOBOCAN 2012 (Fiji, French Polynesia, Guam, New Caledonia, Samoa, Solomon Islands, Vanuatu). The highest cancer incidence and mortality rates were reported in New Caledonia (age-standardized incidence and mortality rates 297.9 and 127.3 per 100.000) and French Polynesia (age-standardized incidence and mortality rates 255.0 and 134.4 per 100.000), with relatively low rates in other countries. Literature indicated that cancer was among the leading causes of deaths in most PICTs; thus they now experience a double burden of cancers linked to infections and life-style and reproductive factors. Further, ethnic differences in cancer incidence and mortality have been reported in some PICTs, including Fiji, Guam, New Caledonia and Northern Mariana Islands.ConclusionCancer incidence in the PICTs was recorded to be relatively low, with New Caledonia and French Polynesia being exceptions. Low recorded incidence is likely to be explained by incomplete cancer registration as cancer had an important contribution to mortality. Further endeavors are needed to develop and strengthen cancer registration infrastructure and practices and to improve data quality and registration coverage in the PICTs.  相似文献   

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