Beyond the surface: Seabirds and plastics as indicators in a large, remote marine protected area.

Marine protected areas (MPAs) are an important conservation tool for species and habitats; however, they are not a panacea solution. For example, MPAs provide little protection from plastic pollution which travels vast distances on ocean currents. Here we document exposure of juvenile Christmas Shearwaters (Puffinus nativitatis) to plastics on uninhabited Ducie Atoll in the remote South Pacific. Despite being surrounded by the very large Pitcairn Islands MPA, most birds (68.7 %; n = 16) contained 3.8 ± 4.1 pieces of ingested plastic. Unexpectedly, the number, mass and frequency of occurrence of plastic in two age classes (young downy chicks and fledglings) was similar. While the reason for this is unknown, it may suggest birds do not acquire new plastic items, or are able to rid themselves of plastics, beyond a certain age. We discuss the potential health consequences of plastic ingestion in Christmas Shearwaters and call for further research of this poorly studied species.

Dengue Virus and Zika Virus Seroprevalence in the South Pacific Populations of the Cook Islands and Vanuatu.

Arboviral diseases are serious threats to global health with increasing prevalence and potentially severe complications. Significant arthropod-borne viruses are the dengue viruses (DENV 1-4), the Zika virus (ZIKV), and the chikungunya virus (CHIKV). Among the areas most affected is the South Pacific Region (SPR). Here, arboviruses not only cause a high local burden of disease, but the region has also proven to contribute to their global spread. Outpatient serum samples collected between 08/2016 and 04/2017 on three islands of the island states of Vanuatu and the Cook Islands were tested for anti-DENV- and anti-ZIKV-specific antibodies (IgG) using enzyme-linked immunosorbent assays (ELISA). ELISA test results showed 89% of all test sera from the Cook Islands and 85% of the Vanuatu samples to be positive for anti-DENV-specific antibodies. Anti-ZIKV antibodies were identified in 66% and 52%, respectively, of the test populations. Statistically significant differences in standardized immunity levels were found only at the intranational level. Our results show that in both the Cook Islands and Vanuatu, residents were exposed to significant Flavivirus transmission. Compared to other seroprevalence studies, the marked difference between ZIKV immunity levels and previously published CHIKV seroprevalence rates in our study populations is surprising. We propose the timing of ZIKV and CHIKV emergence in relation to recurrent DENV outbreaks and the impact of seasonality as explanatory external factors for this observation. Our data add to the knowledge of arboviral epidemics in the SPR and contribute to a better understanding of virus spread, including external conditions with potential influence on outbreak dynamics. These data may support preventive and rapid response measures in the affected areas, travel-related risk assessment, and infection identification in locals and returning travelers.

Principles to guide research and policy on psychological well-being in remote island developing states in the South Pacific.

Adverse climatic changes around the globe and predictions of catastrophic and irreversible alteration in global weather patterns, temperature rise, and coast-line habitability require a careful examination of consequences on the resilience and mental health of people who will endure these changes. This paper is concerned with the South Pacific region. This geography has benefited from a relatively stable climate that is seen in the lush and vibrant natural world with many unique species of plants and animals exclusively found here. This paper examines the psychological profile of the people in the South Pacific using an evolutionary framework, and considers their local climate risks and lifestyle patterns with the aim of exploring possible mental health trajectories.

Insight into planktonic protistan and fungal communities across the nutrient-depleted environment of the South Pacific Subtropical Gyre.

Ocean microorganisms constitute ~70% of the marine biomass, contribute to ~50% of the Earth's primary production, and play a vital role in global biogeochemical cycles. The marine heterotrophic and mixotrophic protistan and fungal communities have often been overlooked mainly due to limitations in morphological species identification. Despite the accumulation of studies on biogeographic patterns observed in microbial communities, our understanding of the abundance and distribution patterns within the microbial community of the largest subtropical gyre, the South Pacific Gyre (SPG), remains incomplete. Here, we investigated the diversity and vertical composition of protistan and fungal communities in the water column of the ultra-oligotrophic SPG. Our results showed apparent differences in protistan community diversity in the photic and aphotic regions. The entire protistan community diversity was significantly affected by temperature, salinity, oxygen, and nutrient concentrations, while the parasitic community diversity was also affected by chlorophyll a concentration. The parasitic protists were assigned to the class Syndiniales accounting for over 98% of the total parasitic protists, exhibiting higher relative sequence abundance along the water depth and displaying consistent patterns among different sampling stations. In contrast to the protistan community, the fungal community along the SPG primarily clustered based on the sampling station and pelagic zones. In particular, our study reveals a significant presence of parasitic protists and functionally diverse fungi in SPG and their potential impact on carbon cycling in the gyre.IMPORTANCEOur findings carry important implications for understanding the distribution patterns of the previously unrecognized occurrence of parasitic protists and functionally diverse fungi in the nutrient-limited South Pacific Gyre. In particular, our study reveals a significant presence of parasitic Syndiniales, predominantly abundant in the upper 300 m of the aphotic zone in the gyre, and a distinct presence of fungal communities in the aphotic zone at the central part of the gyre. These findings strongly suggest that these communities play a substantial role in yet insufficiently described microbial food web. Moreover, our research enhances our understanding of their contribution to the dynamics of the food webs in oligotrophic gyres and is valuable for projecting the ecological consequences of future climate warming.

Spatial distribution of microplastics in a coastal upwelling region: Offshore dispersal from urban sources in the Humboldt Current System.

In coastal waters, higher concentrations of microplastics (MPs) are generally related to densely populated and industrialized areas, but intense upwelling and offshore transport in the Eastern Boundary Upwelling Systems (EBUS) may influence this pattern. The Humboldt Current System (HCS) along the coast of northern-central Chile represents a perfect model to test whether the abundance of MP at the sea surface decreases with distance from land-based sources, e.g., river mouths, harbors, and submarine wastewater outfalls. The sea surface was sampled with a manta trawl to examine the abundance, composition, and distribution of floating MPs, and Generalized Additive Mixed Models (GAMMs) were performed to examine the relationship between MP abundance (particles km-2) and the distance to putative sources. MPs were found in all 57 net tows, with an average of ⁓120,000 MP km-2 and maximum values of ⁓1,500,000 MP km-2. The composition of MPs was dominated by fragments (>50% of the total count) and over 80% of all MPs were ≥1 mm. The combined effect of the various sources, spatially concentrated in urban areas, makes it difficult to distinguish their relative contributions, but the MP composition suggested that rivers are more important sources, followed by submarine wastewater outfalls and then harbors. A significant and steep negative relationship with the "distance to source" explained 15.2% of the variance of "MP abundance", suggesting rapid offshore displacement within the HCS. This is the first study to report this pattern along the edges of the South Pacific Subtropical Gyre (SPSG), revealing that continuous offshore transport of microplastic from land-based sources is occurring over large scales and contributing to the accumulation of microplastics in the center of the SPSG. However, the findings additionally suggested that processes at meso- and submeso-spatial scales (driven by geographic and seasonal variables) are disrupting the general pattern.

Current knowledge on the diversity of Eumolpinae (Coleoptera, Chrysomelidae) in New Caledonia.

The Eumolpinae leaf beetles of New Caledonia are very diverse, but our knowledge about their diversity is still incomplete. Following a renewed interest in the group in the last two decades, there has been an exponential increase in the number of species described, with species descriptions and taxonomic reassessment ongoing. In this work, the catalogue of New Caledonian Eumolpinae is updated, incorporating all these recent changes, and also indicating the collection where type specimens are currently available. The updated catalogue includes 120 species in 13 genera, and more additions and taxonomic changes, including new combinations, are expected in forthcoming years. Here two new synonymies are reported, namely Dumbeastriata Jolivet, Verma & Mille, 2007 = Taophilacancellata Samuelson, 2010, syn. nov.; and Dematochromatheryi Jolivet, Verma & Mille, 2010 = Dematochromapoyensis Jolivet, Verma & Mille, 2010, syn. nov. Moreover, two species still retaining their original adscription to the genus Colaspis Fabricius, 1801, are treated as incertae sedis. This catalogue represents a useful tool for future taxonomic studies of New Caledonian Chrysomelidae and can assist biodiversity surveys and conservation studies within the archipelago.

Daily accumulation rates of floating debris and attached biota on continental and oceanic island shores in the SE Pacific: testing predictions based on global models.

Background: Long-distance rafting on anthropogenic marine debris (AMD) is thought to have a significant impact on global marine biogeography and the dispersal of non-indigenous species. Therefore, early identification of arrival sites of AMD and its epibionts is crucial for the prioritization of preventive measures. As accumulation patterns along global coastlines are largely unstudied, we tested if existing oceanographic models and knowledge about upstream sources of litter and epibionts can be used as a simple and cost-efficient approach for predicting probable arrival sites of AMD-rafting biota in coastal zones. Methods: Using the Southeast Pacific as a model system, we studied daily accumulation rates, composition, and minimum floating times of AMD with and without epibionts on seven sandy beaches, covering the oceanic environment (Rapa Nui/Easter Island) and three regions (south, centre, north) along the Chilean continental coast, over a minimum of 10 consecutive days, and we contrast our results with predictions from published models. Results: Total AMD accumulation rates varied from 56 ± 36 (mean ± standard deviation) to 388 ± 433 items km-1 d-1 and differed strongly between regions, in accordance with local geomorphology and socioeconomic conditions (presence of larger cities and rivers upstream, main economic activities, etc.). Daily accumulation of items with pelagic epibionts (indicators of a pelagic trajectory) ranged from 46 ± 29 (Rapa Nui) to 0.0 items km-1 d-1 (northern continental region). Minimum floating times of rafts, as estimated from the size of pelagic epibionts, were longest in the South Pacific Subtropical Gyre's (SPSG) centre region, followed by the high-latitude continental region under the influence of the onshore West Wind Drift, and decreased along the continental alongshore upwelling current, towards lower latitudes. Apart from pelagic rafters, a wide range of benthic epibionts, including invasive and cryptogenic species, was found on rafts at the continental beaches. Similarly, we present another record of local benthic corals Pocillopora sp., on Rapa Nui rafts. Discussion: Our results agree with the predictions made by recent models based on the prevailing wind and surface current regimes, with high frequencies of long-distance rafting in the oceanic SPSG centre and very low frequencies along the continental coast. These findings confirm the suitability of such models in predicting arrival hotspots of AMD and rafting species. Moreover, storm surges as well as site-related factors seem to influence AMD arrival patterns along the Chilean continental coast and might cause the observed high variability between sampling sites and days. Our results highlight the possible importance of rafting as a vector of along-shore dispersal and range expansions along the SE Pacific continental coast and add to the discussion about its role in benthic species dispersal between South Pacific oceanic islands.

Occurrence, source, and transfer fluxes of organophosphate esters in the South Pacific and Fildes Peninsula, Antarctic.

Concentrations of 11 organophosphate esters (OPEs) were investigated in surface water and atmosphere samples collected from the South Pacific and Fildes Peninsula. TEHP and TCEP were the dominant OPEs in South Pacific dissolved water, with concentration range of nd-106.13 ng/L and 1.06-28.97 ng/L, respectively. The total concentration of ∑10OPEs in the South Pacific atmosphere was higher than that in Fildes Peninsula, ranging from 216.78 to 2033.97 pg/m3 and 161.83 pg/m3, respectively. TCEP and TCPP were the most dominant OPEs in the South Pacific atmosphere, while TPhP was the most prevalent in the Fildes Peninsula. The air-water exchange flux of ∑10OPEs at the South Pacific was 0.04-3.56 ng/m2/day, with a transmission direction of evaporation totally determined by TiBP and TnBP. The atmospheric dry deposition dominated the transport direction of OPEs between air and water, with an flux of Σ10OPEs at 10.28-213.62 ng/m2/day (mean: 85.2 ng/m2/day). The current transport flux of OPEs through the Tasman Sea to the ACC (2.65 × 104 kg/day) was significantly higher than the dry deposition flux over the Tasman Sea(493.55 kg/day), indicating the Tasman Sea's importance as a transport pathway for OPEs from low latitude areas to the South Pacific. Principal component analysis and air mass back-trajectory analysis provided evidence of terrestrial inputs from human activities that have impacted the environment in the South Pacific and the Antarctic.

Tuerkayana latens, a New Species of Land Crab from French Polynesia, with a Discussion on the Phylogeny of the Genus (Crustacea: Decapoda: Brachyura: Gecarcinidae).

The taxonomy of the gecarcinid land crab Tuerkayana rotundum (Quoy & Gaimard, 1824) is revised. The taxon, the type species of the genus, occurs from the western Indian Ocean to the western Pacific, and varies substantially in colour and various morphological features, but the male first gonopod structure is constant and the extensive genetic data from mitochondrial 16S rDNA, cytochrome c oxidase subunit 1 and control region markers confirms the recognition of one wide-ranging species. Specimens from Tuamotu in French Polynesia and Pitcairn Island, however, differ in having a smoother and slightly more swollen carapace, and significantly, the male first gonopod structure is distinctly different. The genetic data also supports their differentiation. As such, this material is here recognised as a new species, Tuerkayana latens n. sp.

Historical Mitogenomic Diversity and Population Structuring of Southern Hemisphere Fin Whales.

Fin whales Balaenoptera physalus were hunted unsustainably across the globe in the 19th and 20th centuries, leading to vast reductions in population size. Whaling catch records indicate the importance of the Southern Ocean for this species; approximately 730,000 fin whales were harvested during the 20th century in the Southern Hemisphere (SH) alone, 94% of which were at high latitudes. Genetic samples from contemporary whales can provide a window to past population size changes, but the challenges of sampling in remote Antarctic waters limit the availability of data. Here, we take advantage of historical samples in the form of bones and baleen available from ex-whaling stations and museums to assess the pre-whaling diversity of this once abundant species. We sequenced 27 historical mitogenomes and 50 historical mitochondrial control region sequences of fin whales to gain insight into the population structure and genetic diversity of Southern Hemisphere fin whales (SHFWs) before and after the whaling. Our data, both independently and when combined with mitogenomes from the literature, suggest SHFWs are highly diverse and may represent a single panmictic population that is genetically differentiated from Northern Hemisphere populations. These are the first historic mitogenomes available for SHFWs, providing a unique time series of genetic data for this species.

A story of vicariance? how the geology of oceanic archipelagos influenced the evolutionary history of endemic damselflies.

South Pacific islands provide an ideal study system to explore patterns of speciation, specifically examining the role of dispersal versus vicariance. Dispersal is often the suggested mechanism of diversification in the South Pacific, specifically among remote island chains. Here, we provide a phylogeny of several related genera of Coenagrionidae (Odonata: Zygoptera) from the South Pacific, based on five molecular loci, in order to examine patterns of speciation in the region. We used the endemic damselfly genera Nesobasis, Nikoulabasis, and Vanuatubasis found across both Fiji and Vanuatu. Knowledge of the geologic history of the region was used to inform our understanding of the evolution of these genera. Both archipelagos used to be part of the Vitiaz arc which spanned from the Solomon Islands to Tonga and began to break apart 10-12 Ma. Results of our divergence-time estimations and biogeographic reconstructions support that the breakup of this arc acted as a significant vicariance event in the evolution of these taxa. Specifically, it led to the extant generic diversity seen in these damselflies. We find that within the archipelago of Vanuatu, that Espiritu Santo served as an important source for dispersal to other islands with Malekula acting as a stepping stone to Efate.

Genome characterization of two novel deep-sea sediment fungi, Penicillium pacificagyrus sp. nov. and Penicillium pacificasedimenti sp. nov., from South Pacific Gyre subseafloor sediments, highlights survivability.

BACKGROUND: Marine deep subsurface sediments were once thought to be devoid of eukaryotic life, but advances in molecular technology have unlocked the presence and activity of well-known closely related terrestrial and marine fungi. Commonly detected fungi in deep marine sediment environments includes Penicillium, Aspergillus, Cladosporium, Fusarium, and Schizophyllum, which could have important implications in carbon and nitrogen cycling in this isolated environment. In order to determine the diversity and unknown metabolic capabilities of fungi in deep-sea sediments, their genomes need to be fully analyzed. In this study, two Penicillium species were isolated from South Pacific Gyre sediment enrichments during Integrated Ocean Drilling Program Expedition 329. The inner gyre has very limited productivity, organic carbon, and nutrients. RESULTS: Here, we present high-quality genomes of two proposed novel Penicillium species using Illumina HiSeq and PacBio sequencing technologies. Single-copy homologues within the genomes were compared to other closely related genomes using OrthoMCL and maximum-likelihood estimation, which showed that these genomes were novel species within the genus Penicillium. We propose to name isolate SPG-F1 as Penicillium pacificasedimenti sp. nov. and SPG-F15 as Penicillium pacificagyrus sp. nov. The resulting genome sizes were 32.6 Mbp and 36.4 Mbp, respectively, and both genomes were greater than 98% complete as determined by the presence of complete single-copy orthologs. The transposable elements for each genome were 4.87% for P. pacificasedimenti and 10.68% for P. pacificagyrus. A total of 12,271 genes were predicted in the P. pacificasedimenti genome and 12,568 genes in P. pacificagyrus. Both isolates contained genes known to be involved in the degradation of recalcitrant carbon, amino acids, and lignin-derived carbon. CONCLUSIONS: Our results provide the first constructed genomes of novel Penicillium isolates from deep marine sediments, which will be useful for future studies of marine subsurface fungal diversity and function. Furthermore, these genomes shed light on the potential impact fungi in marine sediments and the subseafloor could have on global carbon and nitrogen biogeochemical cycles and how they may be persisting in the most energy-limited sedimentary biosphere.

A digital literacy model to narrow the digital literacy skills gap.

The concept of digital literacy is increasingly prevalent in the 21st century. Growing demands from the work sector for individuals to be digitally literate has prompted targeted interventions and innovations from the education sector to instil digital skills into the future workforce. However, despite efforts the digital skills gap remains visible globally. This paper explores the prominent educational frameworks and models, their advantages and limitations in 21st-century learning and teaching. Furthermore, a new innovative digital literacy model has been proposed to be integrated into the existing and future education frameworks and models to assist educationists in narrowing the digital skills gaps and preparing graduates for the work sector. The digital literacy model consists of two components: (1) the digital literacy framework- South Pacific Digital Literacy Framework (SPDLF) and (2) the digital literacy tool. The SPDLF reflects six major literacies identified for the 21st-century while the digital literacy tool--digilitFJ consists of a digital literacy measuring scale and an online intervention program. The exploratory factor analysis showed that the SPDLF was valid. On the other hand, heuristics, student attitude, and satisfaction and effectiveness of the digital literacy tool were also evaluated from the student's perspective to reflect its usefulness. The survey results also showed a positive attitude and perception of the use of the tool. Additionally, Cohen's d value showed that the digital literacy tool was effective. Therefore, if the tool is implemented and adopted, it can narrow the existing digital skills gap in the South Pacific.

A temporal assessment of microplastics distribution on the beaches of three remote islands of the Yasawa archipelago, Fiji.

This is the first study that investigated the presence, distribution, and composition of microplastics, MPs (1-5 mm) on beaches in the Yasawa Islands, Fiji. A temporal assessment over three years on six beaches was undertaken to investigate different beach traits on MP abundance. Average MP concentration was 4.5 ± 11.1 MPs·m-2 with significantly higher concentrations were found on east-facing beaches than west (p < 0.001), and higher on the storm line compared to the high tide line (p < 0.001). No difference was found between tourist and local beaches (p = 0.21). These results demonstrate the role of current-driven ocean transport of plastic pollution in this part of The South Pacific. ATR FT-IR analysis showed that across all sites 34 % of MPs were polypropylene (PP), 33 % polystyrene (PS), 25 % polyethylene (PE), and 8 % other polymer types. Further studies are needed to assess the potential impacts of MPs on Fiji's coral reefs and marine life.

Humpback whale song revolutions continue to spread from the central into the eastern South Pacific.

Cultural transmission of behaviour is an important aspect of many animal communities ranging from humans to birds. Male humpback whales (Megaptera novaeangliae) sing a repetitive, stereotyped, socially learnt and culturally transmitted song display that slowly evolves each year. Most males within a population sing the same, slow-evolving song type; but in the South Pacific, song 'revolutions' have led to rapid and complete replacement of one song type by another introduced from a neighbouring population. Songs spread eastwards, from eastern Australia to French Polynesia, but the easterly extent of this transmission was unknown. Here, we investigated whether song revolutions continue to spread from the central (French Polynesia) into the eastern (Ecuador) South Pacific region. Similarity analyses using three consecutive years of song data (2016-2018) revealed that song themes recorded in 2016-2018 French Polynesian song matched song themes sung in 2018 Ecuadorian song, suggesting continued easterly transmission of song to Ecuador, and vocal connectivity across the entire South Pacific Ocean basin. This study demonstrates songs first identified in western populations can be transmitted across the entire South Pacific, supporting the potential for a circumpolar Southern Hemisphere cultural transmission of song and a vocal culture rivalled in its extent only by our own.

Quantification and characterization of microplastics in commercial fish from southern New Zealand.

Plastics are ubiquitous throughout global marine ecosystems. To date, there has been limited research on the prevalence of microplastic ingestion by commercially important marine fish in the southern hemisphere, particularly in the South Pacific. Therefore, this research aimed to quantify ingested microplastics from ten commercially important fish species from southern New Zealand using microscopy and Raman spectroscopy. Overall, we found evidence of microplastic ingestion in 75 % of fish, with an average of 2.5 individual particles per fish. Microplastic fibers were the most commonly ingested. The most common colored microplastics ingested were blue, black and red, and 99.68 % of plastics identified were smaller than 5 mm. Raman spectroscopy of plastics recovered from nine fish species found polyethylene and polypropylene to be the most common plastic polymers ingested. Further research is necessary to ascertain the human ecological and health risks involved when exposed to microplastics through eating plastic contaminated fish.

Relationships of Tobacco Use and Kava Consumption to Sex-Associated Variation in Body Composition and Obesity Risk in Melanesian Adults From Vanuatu.

Obesity prevalence has increased in low- and middle-income countries (LMICs) over the past several decades, with generally greater occurrence among adult females compared with males. Gendered variation in health behaviors, such as substance use, may play a role in how differences in obesity, body size, and composition manifest in association with sex. This study examines sex-moderated relationships of tobacco smoking and kava consumption with body composition and obesity among 301 Ni-Vanuatu (local self-identification meaning "of Vanuatu") adults. Data collected included self-reported frequency of substance use as well as anthropometric measurements to assess body mass, composition, and obesity. Tobacco and kava use were associated with reduced measurements of body mass and adiposity in males, and kava use was associated with some elevated measurements of body mass and hip circumference in females. Kava use was also negatively associated with obesity based on waist-to-height ratio among males. These results have implications for evaluation and future research on substance control programs in this population.

The economic vulnerability of fishing households to climate change in the south Pacific region of Colombia.

Climate change's direct and indirect effects on marine ecosystems and coastal areas mainly impact small-scale fishers, especially in developing countries, which present extreme poverty and high dependency on marine ecosystems as a source of food and sustenance for households. Understanding the vulnerability of fishing households and considering the associated socio-economic-political complexities is essential for preserving their livelihoods and maintaining their well-being. This study proposes a measure of economic vulnerability based on the capacity of fishing households in Tumaco, located on the southern Pacific coast of Colombia, to diversify their livelihoods. Different statistical procedures have been conducted to identify the most relevant strategies in reducing the economic vulnerability of households. The results indicate that reducing the vulnerability of fishing households depends on adaptation strategies such as occupational mobility, some elements of social capital, and reduced dependence on the fisheries resource. This study could constitute an input for creating public policy that guides efforts to achieve strategies for the generation of other livelihoods and the sustainability of fishing households that continue to choose fishing as their main economic activity.

Associations between bacterial communities and microplastics from surface seawater of the Northern Patagonian area of Chile.

The presence of microplastics in oceans and coastlines has increased during recent years due anthropogenic activities and represents a serious environmental problem. The establishment and assembly of microbial communities in these microplastics, specifically located near aquaculture activities, is not well understood. In this study, we analyzed unique and core members of bacterial communities attached to microplastics collected from three coastal environments of the South Pacific, which represent low, medium and high anthropogenic activity derived from the aquaculture industry. Microplastics were analyzed with Fourier-transform infrared spectroscopy, scanning electron microscopy, and next-generation sequencing to assess the prevailing microplastics types, and to characterize microbial communities attached to them. We identified four main types of microplastics (polypropylene, polyethylene, nylon and polystyrene) and 3102 Operational Taxonomic Units (OTUs) at the sampled sites, which were dominated by the phylum Cyanobacteria, Bacteroidetes and Proteobacteria (mainly Alpha and Gammaproteobacteria). Similarity index analysis showed that bacterial communities in microplastics differed from those found in the surrounding seawaters, and also that they varied among locations, suggesting a role of the environment and level of anthropogenic activities on the plastisphere taxa. Despite this difference, 222 bacterial OTUs were shared among the three sites representing between 34 and 51% of OTUs of each sampled site, and thus constituted a core microbiome of microplastics. Comparison of the core microbiome with bacterial communities of the surrounding seawater suggested that the plastisphere constituted a selective habitat for diverse microbial communities. Computational predictions also provided evidence of significantly enriched functions in the core microbiome. Co-occurrence networks revealed that putative ecological interactions among microplastics OTUs was dominated by positive correlations. To the best of our knowledge, this is the first study that evaluated the composition of microbial communities found in microplastics from the Patagonia region of the Southern Pacific Ocean.

Feeding Habits of Sarda chiliensis chiliensis (Cuvier, 1832) in Northern Chile and Southern Perú.

The trophic relationships of pelagic fishes with migratory traits such as the South Pacific Bonito, Sarda chiliensis chiliensis (Cuvier, 1832), have not been studied in depth in the past. The objective of the present research was to analyze the feeding habits of South Pacific Bonito by sex and to analyze a comparison between summer and autumn months in three different areas of the eastern South Pacific by applying different techniques used in trophic biology. Between December 2013 and June 2014, specimens were captured in the areas of Pozo de Lisas (Ilo, Peru), La Capilla (Arica, Chile) and Chanavayita (Iquique, Chile). The feeding dynamics and trophic composition of the diet were analyzed, as well as the feeding strategy and trophic relationships. A total of 1404 specimens were analyzed, of which 654 had stomach contents. Seven prey items were identified: (a) fish remains; (b) squid jaw remains; (c) squid gladius remains; (d) caudal fin remains; (e) Engraulis rigens; (f) Pleuroncodes monodon and (g) N/A (not determined). The Pozo de Lisas and La Capilla areas showed homogeneity in their prey items, while the Chanavayita area showed more diversity. Regarding the importance of prey items in the diet of S. chiliensis in the three localities, it would be correct to state that it is a generalist species.