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Disentangling the effects of cyclical variability in environmental forcing and long-term climate change on natural communities is a major challenge for ecologists, managers, and policy makers across ecosystems. Here we examined whether the vertical distribution of rocky intertidal taxa has shifted with sea-level variability occurring at multiple temporal scales and/or long-term anthropogenic sea-level rise (SLR). Because of the distinct zonation characteristic of intertidal communities, any shift in tidal dynamics or average sea level is expected to have large impacts on community structure and function. We found that across the Northeast Pacific Coast (NPC), sea level exhibits cyclical seasonal variability, tidal amplitude exhibits ecologically significant variability coherent with the 18.6-year periodicity of lunar declination, and long-term sea-level rise is occurring. Intertidal taxa largely do not exhibit significant vertical distribution shifts coherent with short-term (monthly to annual) sea-level variability but do exhibit taxa-specific vertical distribution shifts coherent with cyclical changes in lunar declination and long-term SLR at decadal timescales. Finally, our results show that responses to cyclical celestial mechanics and SLR vary among taxa, primarily according to their vertical distribution. Long-term SLR is occurring on ecologically relevant scales, but the confounding effects of cyclical celestial mechanics make interpreting shifts in zonation or community structure challenging. Such cyclical dynamics alternatingly amplify and dampen long-term SLR impacts and may modify the impacts of other global change related stressors, such as extreme heat waves and swell events, on intertidal organisms living at the edge of their physiological tolerances. As a result, intertidal communities will likely experience cyclical periods of environmental stress and concomitant nonlinear shifts in structure and function as long-term climate change continues. Our results demonstrate that consistent, large-scale monitoring of marine ecosystems is critical for understanding natural variability in communities and documenting long-term change.

The precision of estimates of abundance based on data from fishery-independent surveys generally increases with sample size, assuming the availability of a species to sampling remains constant. In practice, the [...]

1. Introduction In early September 2022, tropical cyclone (TC) Hinnamnor struck South Korea, resulting in 12 fatalities and tremendous socioeconomic damages. (1) Hinnamnor was the first super typhoon (lifetime maximum [...]

Deep ocean foraging northern elephant seals (Mirounga angustirostris) consume fish and squid in remote depths of the North Pacific Ocean. Contaminants bioaccumulated from prey are subsequently transferred by adult females to pups during gestation and lactation, linking pups to mercury contamination in mesopelagic food webs (200-1000 m depths). Maternal transfer of mercury to developing seal pups was related to maternal mercury contamination and was strongly correlated with maternal foraging behavior (biotelemetry and isotopes). Mercury concentrations in lanugo (hair grown in utero) were among the highest observed worldwide for young pinnipeds (geometric mean 23.01 μg/g dw, range 8.03-63.09 μg/g dw; n = 373); thus, some pups may be at an elevated risk of sub-lethal adverse health effects. Fetal mercury exposure was affected by maternal foraging geographic location and depth; mercury concentrations were highest in pups of the deepest diving, pelagic females. Moreover, pup lanugo mercury concentrations were strongly repeatable among successive pups of individual females, demonstrating relative consistency in pup mercury exposure based on maternal foraging strategies. Northern elephant seals are biosentinels of a remote deep-sea ecosystem. Our results suggest that mercury within North Pacific mesopelagic food webs may also pose an elevated risk to other mesopelagic-foraging predators and their offspring.

Kelp forests are highly productive and economically important ecosystems worldwide, especially in the North Pacific Ocean. However, current hypotheses for their evolutionary origins are reliant on a scant fossil record. Here, we report fossil hapteral kelp holdfasts from western Washington State, USA, indicating that kelp has existed in the northeastern Pacific Ocean since the earliest Oligocene. This is consistent with the proposed North Pacific origin of kelp associated with global cooling around the Eocene-Oligocene transition. These fossils also support the hypotheses that a hapteral holdfast, rather than a discoid holdfast, is the ancestral state in complex kelps and suggest that early kelps likely had a flexible rather than a stiff stipe. Early kelps were possibly grazed upon by mammals like desmostylians, but fossil evidence of the complex ecological interactions known from extant kelp forests is lacking. The fossil record further indicates that the present-day, multi-story kelp forest had developed at latest after the mid-Miocene climate optimum. In summary, the fossils signify a stepwise evolution of the kelp ecosystem in the North Pacific, likely enabled by changes in the ocean-climate system.

Trait-based frameworks are increasingly used for predicting how ecological communities respond to ongoing global change. As species range shifts result in novel encounters between predators and prey, identifying prey guilds, based on a suite of shared traits, can distill complex species interactions, and aid in predicting food web dynamics. To support advances in trait-based research in open-ocean systems, we present the Pelagic Species Trait Database, an extensive resource documenting functional traits of 529 pelagic fish and invertebrate species in a single, open-source repository. We synthesized literature sources and online resources, conducted morphometric analysis of species images, as well as laboratory analyses of trawl-captured specimens to collate traits describing 1) habitat use and behavior, 2) morphology, 3) nutritional quality, and 4) population status information. Species in the dataset primarily inhabit the California Current system and broader NE Pacific Ocean, but also includes pelagic species known to be consumed by top ocean predators from other ocean basins. The aim of this dataset is to enhance the use of trait-based approaches in marine ecosystems and for predator populations worldwide.

The impact of microbiome in animal physiology is well appreciated, but characterization of animal-microbe symbiosis in marine environments remains a growing need. This study characterizes the microbial communities associated with the moon jellyfish Aurelia coerulea, first isolated from the East Pacific Ocean and has since been utilized as an experimental system. We find that the microbiome of this Pacific Aurelia culture is dominated by two taxa, a Mollicutes and Rickettsiales. The microbiome is stable across life stages, although composition varies. Mining the host sequencing data, we assembled the bacterial metagenome-assembled genomes (MAGs). The bacterial MAGs are highly reduced, and predict a high metabolic dependence on the host. Analysis using multiple metrics suggest that both bacteria are likely new species. We therefore propose the names Ca. Mariplasma lunae (Mollicutes) and Ca. Marinirickettsia aquamalans (Rickettsiales). Finally, comparison with studies of Aurelia from other geographical populations suggests the association with Ca. Mariplasma lunae occurs in Aurelia from multiple geographical locations. The low-diversity microbiome of Aurelia provides a relatively simple system to study host-microbe interactions.

Marine heatwaves (MHWs) have adverse impacts on marine ecosystems and fisheries, yet extreme MHWs in the western tropical Pacific Ocean remain largely unexplored. Here, we investigate the evolution and drivers of the two strongest subsurface MHWs in the western tropical Pacific Ocean on record, in 2008 (MHW-08) and 2010–11 (MHW-11). The two events have similar evolutions, as they were both initiated and developed locally in tropical regions during their onset phase and gradually dissipated with multiple cores during the decay phase. We examined the physical processes during the evolution of MHW-08 and MHW-11 and performed a heat budget analysis for the subsurface layer in each case. We find that the onset of both events were mainly controlled by convergence and vertical heat advection due to anomalous Ekman downwelling, while the decay of both events was mainly controlled by horizontal heat advection due to anomalous horizontal currents and withdrawal of anomalous convergence. The relationship between the subsurface MHWs and El Niño–Southern Oscillation is discussed. We suggest that the anomalous heat advections plus the La Niña–related background warming lead to the extreme subsurface MHW events. Our findings may have important implications for environmental change and marine life in the western tropical Pacific Ocean. [ABSTRACT FROM AUTHOR]

Background: An increase in upper-ocean thermal stratification is being observed worldwide due to global warming. However, how ocean stratification affects the vertical profile of plankton communities remains unclear. Understanding this is crucial for assessing the broader implications of ocean stratification. Pelagic ciliates cover multiple functional groups, and thus can serve as a model for studying the vertical distribution and functional strategies of plankton in stratified oceans. We hypothesize that pelagic ciliate communities exhibit vertical stratification caused by shifts in functional strategies, from free-living groups in the photic zone to parasitic groups in deeper waters. Results: 306 samples from the surface to the abyssopelagic zone were collected from 31 stations in the western Pacific and analyzed with environmental DNA (the V4 region of 18 S rDNA) metabarcoding of pelagic ciliates. We found a distinct vertical stratification of the entire ciliate communities, with a boundary at a depth of 200 m. Significant distance-decay patterns were found in the photic layers of 5 m to the deep chlorophyll maximum and in the 2,000 m, 3000 m and bottom layers, while no significant pattern occurred in the mesopelagic layers of 200 m – 1,000 m. Below 200 m, parasitic Oligohymenophorea and Colpodea became more prevalent. A linear model showed that parasitic taxa were the main groups causing community variation along the water column. With increasing depth below 200 m, the ASV and sequence proportions of parasitic taxa increased. Statistical analyses indicated that water temperature shaped the photic communities, while parasitic taxa had a significant influence on the aphotic communities below 200 m. Conclusions: This study provides new insights into oceanic vertical distribution, connectivity and stratification from a biological perspective. The observed shift of functional strategies from free-living to parasitic groups at a 200 m transition layer improves our understanding of ocean ecosystems in the context of global warming. [ABSTRACT FROM AUTHOR]

The article explores the expansion of U.S. empire in the decade before the American Civil War to search for cheap access to guano fertilizers across the Pacific Ocean. It argues that the practices of southern cash crop cultivation that relied on soil mining contributed to the growth of domestic demand for imported guano fertilizers. It focuses on a region called the Chesapeake South as the primary leading force behind the expansionary policy of the U.S.

Throughout the western tropical Pacific Ocean, eddies and currents play an important role in biogeochemical cycling. Many studies have investigated the effects of hydrography on vertical patterns of picophytoplankton and heterotrophic bacterial abundance in mesoscale eddies. There is a lack of field observations to determine what impact dynamic hydrological systems of eddies have on prokaryotic community activity (growth and mortality rates). An objective of this study was to examine how anticyclonic eddies influence picoplankton abundance and activity (growth and mortality rates). To meet this purpose, heterotrophic bacterial and picophytoplankton growth and mortality rates were examined by modified dilution experiments conducted at the surface, deep chlorophyll maximum (DCM), and 200 m depth outside (OE) and inside of warm eddies core (EC) in the west Pacific Ocean. A high heterotrophic bacterial grazing rate was found in the EC region in the present study. Furthermore, the picophytoplankton grazing rate in EC was frequently greater than the grazing rate in OE. Furthermore, the higher grazing rates in the EC region cause a lower proportion of viral lysis to account for heterotrophic bacteria and picophytoplankton mortality. The results of our experiments suggest that downwelling in EC might increase picophytoplankton growth and grazing rates, increasing the carbon sink in the warm eddy and potentially increasing ocean carbon storage. [ABSTRACT FROM AUTHOR]

Satellite altimetry data, with its increasing density and quality, has become the primary source for marine deflection of the vertical (DOV) and gravity anomaly modelling. Limited by orbital inclinations, the precision of the meridian component of the gridded deflection of the vertical (GDOV) calculated by traditional altimetry satellites is significantly better than that of the prime vertical component, and the excessive precision difference between these two components restricts the inversion precision of marine gravity anomaly model. The study of cross-track deflection of the vertical (CTDOV) is enabled by the multibeam synchronous observation mode of the new laser altimetry satellite, Ice, Cloud and Land Elevation Satellite-2 (ICESat-2). Based on the remove-restore method, residual geoid gradients are first calculated in this paper using three approaches: along-track (A-T), cross-track (C-T) and an integration of along-track and cross-track. Vertical deflections are then computed on a 1′ × 1′ grid using the least squares collocation (LSC) method, and the precision is verified against the SIO V32.1_DOV model. An optimized combination is proposed to address the issue of precision differences between the meridian and prime vertical components, and to enhance the precision of DOV inversion. A new DOV combination is formed by combining the meridian component from along-track deflection of the vertical (ATDOV) with the prime vertical component from cross-track deflection of the vertical (CTDOV) based on the remove-restore method. The Philippine Sea (0°–35°N, 120°–150°E) is selected as the test area to verify the feasibility of the optimized combination. The results indicate that the optimized combination of the meridian and prime vertical components achieved test precision of 2.63 and 3.33 μrad, respectively, when compared against the SIO V32.1_DOV model. The precision gap between the components is effectively narrowed by this approach, which maintains the precision of the meridian component and enhances that of the prime vertical component, thereby achieving optimal inversion precision for gravity anomalies. [ABSTRACT FROM AUTHOR]

The Bohai Bay Basin, as a super oil-rich basin in the world, is characterized by cyclic evolution and complex regional tectonic stress field, and its lifecycle tectonic evolution controls the formation of regional source rocks. The main pre-Cenozoic stratigraphic system and lithological distribution are determined through geological mapping, and the dynamics of the pre-Cenozoic geotectonic evolution of the Bohai Bay Basin are investigated systematically using the newly acquired high-quality seismic data and the latest exploration results in the study area. The North China Craton where the Bohai Bay Basin is located in rests at the intersection of three tectonic domains: the Paleo-Asian Ocean, the Tethys Ocean, and the Pacific Ocean. It has experienced the alternation and superposition of tectonic cycles of different periods, directions and natures, and experienced five stages of the tectonic evolution and sedimentary building, i.e. Middle-Late Proterozoic continental rift trough, Early Paleozoic marginal-craton depression carbonate building, Late Paleozoic marine-continental transitional intracraton depression, Mesozoic intracontinental strike-slip-extensional tectonics, and Cenozoic intracontinental rifting. The cyclic evolution of the basin, especially the multi-stage compression, strike-slip and extensional tectonics processes in the Hercynian, Indosinian, Yanshan and Himalayan since the Late Paleozoic, controlled the development, reconstruction and preservation of several sets of high-quality source rocks, represented by the Late Paleozoic Carboniferous-Permian coal-measure source rocks and the Paleogene world-class extra-high-quality lacustrine source rocks, which provided an important guarantee for the hydrocarbon accumulation in the super oil-rich basin. [ABSTRACT FROM AUTHOR]

The objective functions adopted by earthquake early warning (EEW) location algorithms are inadequate for out-of-network earthquakes. As a result, the real-time locations of these earthquakes are often erroneous. The consequences of mislocating out-of-network earthquakes are that their magnitudes are miscalculated, and the loci of their shaking predictions map are shifted. Given that the largest earthquakes occur in subduction settings, improving real-time out-of-network earthquake location is of great importance. In this study, the Virtual Dynamically Assembled Array Algorithm (ViDA³) is introduced, which addresses the location issue of offshore and off-network earthquakes. The guiding principle underlying the new EEW location algorithm is that standard seismic networks may be viewed as a collection of medium-sized seismic arrays, with each array consisting of three or more network stations. The potential of array seismology for EEW against out-of-network earthquakes stems primarily from the slowness vector, which points at the direction of the epicentral region. Thus, this region may be constrained merely by intersecting two or more such vectors. In addition, the length of the slowness vector depends on the hypocentral distance and depth and is thus vital for addressing an acute problem in a subduction setting--discriminating between upper crust and deep slab earthquakes. Furthermore, when the slowness of the P phase is known, the slowness of the S phase is deduced, and the S-phase arrival is searched for using the shift-and-sum practice. What makes ViDA³ so attractive is that, in locations where a real-time network is already in place, these added values may be achieved without extra hardware or substantial budget requirements. We present the result of ViDA³ real-time operation on a shallow earthquake offshore Vancouver Island and the result of its replay on a deep slab earthquake in northern Chile. performance is further assessed using a dataset of seismograms from the Mendocino Triple Junction area. It is concluded that ViDA³ location scheme outperforms currently available EEW location algorithms for out-of-network earthquakes. [ABSTRACT FROM AUTHOR]

Findings of frilled sharks (both fossil and modern) are very rare, primarily due to their deep-sea lifestyle. A tooth of frilled shark Chlamydoselachus kamchaticus sp. nov. has been found in the Upper Eocene sediments of the Peresheek Mountain Formation on Karaginsky Island (Bering Sea, off northeastern Kamchatka). The large size of the tooth suggests a fish size close to the maximum for the genus, more than twice the size of modern Chlamydoselachus. This find is northernmost for fossil frilled sharks and located 20° north of the modern northern limit of the genus' distribution in the Pacific Ocean. This may indicate a warmer climate in the Late Eocene than the current climate conditions in the region of Eastern Kamchatka. [ABSTRACT FROM AUTHOR]

Nowadays, numerous governments have instituted diverse regulatory frameworks aimed at fostering the assimilation of sustainable energy sources characterized by reduced environmental footprints. Solar, wind, geothermal, and ocean energies were subject to extensive scrutiny, owing to their ecological merits. However, these sources exhibit pronounced temporal fluctuations. Notably, ocean dynamics offer vast energy reservoirs, with oceanic waves containing significant amounts of energy. In the Central American Pacific context, the exploration of wave energy resources is currently underway. Accurate numerical wave models are required for applied studies such as those focused on the estimation of exploitable wave power; and even more so in Central American region of the Pacific Ocean where existing numerical models simulations have so far relied on coarse resolution and limited validation field data. This work presents a high-resolution unstructured wave hindcast over the Central American Pacific region, implemented using the third-generation spectral wave model WAVEWATCH III over the period between 1979 and 2021. The results of the significant wave height have been bias-corrected on the basis of satellite information spanning 2005 to 2015, and further validation was performed using wave buoy and acoustic Doppler current profiler (ADCP) records located in the nearshore region of the Central America Pacific coast. After correction and validation of the wave hindcast, we employed the dataset for the evaluation and assessment of wave energy and its possible exploitation using different wave energy converters (WECs). This evaluation addressed the need to diverse the energy portfolio within the exclusive economic zones of Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama, Colombia, and Ecuador in a sustainable manner. Moreover, a comprehensive analysis was carried out on the advantages of harnessing wave energy, juxtaposed with the imperative of regulatory frameworks and the current dearth of economic and environmental guidelines requisite for development within the region. [ABSTRACT FROM AUTHOR]

The prevalence of endoparasites associated with chaetognath abundance in the coastal waters of the Mexican Central Pacific was studied fortnightly from November 2010 to December 2011. A total of 35 (0.21%) out of 16,407 chaetognaths were found to be parasitized. Five out of twelve chaetognath species (Flaccisagitta enflata, F. hexaptera, Parasagitta euneritica, Serratosagitta pacifica, Zonosagitta bedoti) were found to be parasitized by nine endoparasitic taxa: Protists (two morphotypes), digenean metacercariae [Didymozoidae, Hemiuridae, Parahemiurus sp., Lepocreadiidae, Prosorhynchus sp. (Bucephalidae)], and cestodes (metacestodes) [Tetraphyllidea (two morphotypes)]. Parasagitta. euneritica and Z. bedoti were the most abundant chaetognath species, and Protist sp. 2 and Tetraphyllidea sp. 1 were the most abundant parasites. The highest prevalence for most of the endoparasite species occurred in June, and the values varied according to three hydroclimatic periods: stratified (S), semi-mixed (SM), and mixed (M). Eight non-infected chaetognath species, two parasitized chaetognaths (F. enflata and S. pacifica), and two parasites (Protist sp. 1 and Tetraphyllidea sp. 2) were associated with warm temperatures (S and SM periods); in contrast, P. euneritica, Z. bedoti, parasitized F. hexaptera, and the parasite Tetraphyllidea sp. 1 showed a strong local preference for cooler temperatures, high productivity, and high biomass conditions (M periods). We discovered the occurrence of the digenean Prosorhynchus sp. (Bucephalidae) parasitizing the chaetognath P. euneritica, and this is the first report of Prosorhynchus parasitizing chaetognaths worldwide. We also confirmed the presence of Lepocrediidae (metacercariae larval stage) infecting F. hexaptera, a parasite that had only been recorded infecting other chaetognaths of the Atlantic Ocean. The parasite diversity affecting the chaetognath populations of the Central Mexican Pacific coast likely differs between the offshore, outer slope areas, and the surveyed coastal system. [ABSTRACT FROM AUTHOR]

The hadal zone (water depths > 6000 m) are unlike the overlying shallower marine regions (bathyal and abyssal) as it does not follow a continuum from the continental shelves to abyssal plains, but rather exhibits a globally disjunct series of discrete deep-sea habitats confined within geomorphological features. From an ecological perspective, hadal communities are often endemic to individual or adjacent features and are partitioned and isolated by geomorphological structures. To examine the size, shape, depth and degree of isolation of features where hadal fauna inhabit, this study explores the broad seafloor geomorphology, and distinctly partitioned hadal areas, across the Southwest Pacific and East Indian oceans using global bathymetric datasets. This research revealed the area occupied by hadal depths to be 716,915 km2 of which 58% are accounted for by trenches, 37% in basins and troughs, and 5% fracture zones. The largest feature in terms of area > 6000 m depth is the Wharton Basin with 218,030 km2 spanning 376 discrete areas. The largest continuous hadal habitats were the Kermadec and Tonga trenches at 145,103 and 111,951 km2 respectively, whereas features such as the Java Trench comprise two hadal components partitioned by a bathymetric high. Conversely, no physical barrier exists between the New Britain and Bougainville trenches thus any literature pertaining to hadal species or habitats from these trenches can be merged. This study highlights that the hadal zone mainly comprises two main geomorphological features (trenches and basins) that differ in size, depth and complexity. Hadal basins cover vast, generally shallower areas, comparable to abyssal plains, whereas trenches, despite a lesser footprint, represent greater depth ranges and complexity. As such, sampling designs and interpretation of ecological data must differ and hadal basins likely play an increasingly important role in understanding ecological shifts from abyssal to hadal ecosystems. [ABSTRACT FROM AUTHOR]

Abstract Background An increase in upper-ocean thermal stratification is being observed worldwide due to global warming. However, how ocean stratification affects the vertical profile of plankton communities remains unclear. Understanding this is crucial for assessing the broader implications of ocean stratification. Pelagic ciliates cover multiple functional groups, and thus can serve as a model for studying the vertical distribution and functional strategies of plankton in stratified oceans. We hypothesize that pelagic ciliate communities exhibit vertical stratification caused by shifts in functional strategies, from free-living groups in the photic zone to parasitic groups in deeper waters. Results 306 samples from the surface to the abyssopelagic zone were collected from 31 stations in the western Pacific and analyzed with environmental DNA (the V4 region of 18 S rDNA) metabarcoding of pelagic ciliates. We found a distinct vertical stratification of the entire ciliate communities, with a boundary at a depth of 200 m. Significant distance-decay patterns were found in the photic layers of 5 m to the deep chlorophyll maximum and in the 2,000 m, 3000 m and bottom layers, while no significant pattern occurred in the mesopelagic layers of 200 m – 1,000 m. Below 200 m, parasitic Oligohymenophorea and Colpodea became more prevalent. A linear model showed that parasitic taxa were the main groups causing community variation along the water column. With increasing depth below 200 m, the ASV and sequence proportions of parasitic taxa increased. Statistical analyses indicated that water temperature shaped the photic communities, while parasitic taxa had a significant influence on the aphotic communities below 200 m. Conclusions This study provides new insights into oceanic vertical distribution, connectivity and stratification from a biological perspective. The observed shift of functional strategies from free-living to parasitic groups at a 200 m transition layer improves our understanding of ocean ecosystems in the context of global warming. Graphical Abstract

The prevalence of endoparasites associated with chaetognath abundance in the coastal waters of the Mexican Central Pacific was studied fortnightly from November 2010 to December 2011. A total of 35 (0.21%) out of 16,407 chaetognaths were found to be parasitized. Five out of twelve chaetognath species (Flaccisagitta enflata, F. hexaptera, Parasagitta euneritica, Serratosagitta pacifica, Zonosagitta bedoti) were found to be parasitized by nine endoparasitic taxa: Protists (two morphotypes), digenean metacercariae [Didymozoidae, Hemiuridae, Parahemiurus sp., Lepocreadiidae, Prosorhynchus sp. (Bucephalidae)], and cestodes (metacestodes) [Tetraphyllidea (two morphotypes)]. Parasagitta. euneritica and Z. bedoti were the most abundant chaetognath species, and Protist sp. 2 and Tetraphyllidea sp. 1 were the most abundant parasites. The highest prevalence for most of the endoparasite species occurred in June, and the values varied according to three hydroclimatic periods: stratified (S), semi-mixed (SM), and mixed (M). Eight non-infected chaetognath species, two parasitized chaetognaths (F. enflata and S. pacifica), and two parasites (Protist sp. 1 and Tetraphyllidea sp. 2) were associated with warm temperatures (S and SM periods); in contrast, P. euneritica, Z. bedoti, parasitized F. hexaptera, and the parasite Tetraphyllidea sp. 1 showed a strong local preference for cooler temperatures, high productivity, and high biomass conditions (M periods). We discovered the occurrence of the digenean Prosorhynchus sp. (Bucephalidae) parasitizing the chaetognath P. euneritica, and this is the first report of Prosorhynchus parasitizing chaetognaths worldwide. We also confirmed the presence of Lepocrediidae (metacercariae larval stage) infecting F. hexaptera, a parasite that had only been recorded infecting other chaetognaths of the Atlantic Ocean. The parasite diversity affecting the chaetognath populations of the Central Mexican Pacific coast likely differs between the offshore, outer slope areas, and the surveyed coastal system.

Recent field surveys of the flora of Niue have identified three new species records for the island. Erigeron bellioides DC. (Asteraceae) and Psidium cattleyanum Sabine (Myrtaceae) are new naturalised records and Crepidomanes saxifragoides (C.Presl) P.S.Green (Hymenophyllaceae) is an addition to the indigenous flora. Crepidomanes is a new genus for the indigenous flora of Niue. Information is provided for each of these species on their biostatus, collections, distribution and habitats. Erigeron bellioides is known from several locations that provide access to sea and chasm walks where it mostly occupies disturbed and grassy habitats used for car parks. It is most probably being spread by seeds adhering to tourists’ footwear and vehicle tyres as they move between popular attractions. In contrast, Psidium cattleyanum is known from a single plant on the margin of regenerating secondary forest along the Puluhiki Sea Track (Lakepa). It is unlikely to have been planted at this site and may be cultivated in the nearby Lakepa village, which could be the seed source for the established wild plant. Psidium cattleyanum is an invasive species on other Pacific Islands and we recommend removal of the single known plant and survey for it elsewhere, including gardens of the villages. Crepidomanes saxifragoides is known from a single collection in primary forest of the Huvalu Forest Conservation Area where it grew on the shaded and moist surface of a root buttress at the base of a trunk of Syzygium. [ABSTRACT FROM AUTHOR]

Annual wheat yields have steadily risen over the past century, but harvests remain highly variable and dependent on myriad weather conditions during a long growing season. In Kansas, for example, the 2014 crop year brought the lowest average yield in decades at 28 bushels per acre, while in 2016 farmers in the Wheat State, as Kansas is often called, enjoyed a historic high of 57 bushels per acre. It is broadly known that remote forces like El Niño–Southern Oscillation contribute to meteorological outcomes across North America, including in the wheat-growing regions of the U.S. Midwest, but the differential imprints of ENSO phases and flavors have not been well explored as leading indicators for harvest outcomes in highly specific agricultural regions, such as the more than 7 million acres upon which wheat is grown in Kansas. Here, we demonstrate a strong, steady, and long-term association between a simple "wheat yield index" and sea surface temperature anomalies, more than a year earlier, in the East Pacific, potentially offering insights into forthcoming harvest yields several seasons before planting commences. [ABSTRACT FROM AUTHOR]

SUMMARY: Applications of machine learning in seismology have greatly improved our capability of detecting earthquakes in large seismic data archives. Most of these efforts have been focused on continental shallow earthquakes, but here we introduce an integrated deep-learning-based workflow to detect deep earthquakes recorded by a temporary array of ocean-bottom seismographs (OBSs) and land-based stations in the Tonga subduction zone. We develop a new phase picker, PhaseNet-TF, to detect and pick P- and S-wave arrivals in the time–frequency domain. The frequency-domain information is critical for analysing OBS data, particularly the horizontal components, because they are contaminated by signals of ocean-bottom currents and other noise sources in certain frequency bands. PhaseNet-TF shows a much better performance in picking S waves at OBSs and land stations compared to its predecessor PhaseNet. The predicted phases are associated using an improved Gaussian Mixture Model Associator GaMMA-1D and then relocated with a double-difference package teletomoDD. We further enhance the model performance with a semi-supervised learning approach by iteratively refining labelled data and retraining PhaseNet-TF. This approach effectively suppresses false picks and significantly improves the detection of small earthquakes. The new catalogue of Tonga deep earthquakes contains more than 10 times more events compared to the reference catalogue that was analysed manually. This deep-learning-enhanced catalogue reveals Tonga seismicity in unprecedented detail, and better defines the lateral extent of the double-seismic zone at intermediate depths and the location of four large deep-focus earthquakes relative to background seismicity. It also offers new potential for deciphering deep earthquake mechanisms, refining tomographic models, and understanding of subduction processes. [ABSTRACT FROM AUTHOR]

Introduction: Global shipping has accelerated the spread of non-native species. Factors such as environmental filtering and interactions with local biota can affect invasion likelihood, yet their relative contribution to predicting invasion risk remains unresolved. To test how abiotic filters and an experimentally-derived measure of biotic resistance interact with propagule pressure, we developed an integratedmodel to evaluate their relative effects on invasion risk of marine biofouling organisms to different focal port regions. We predicted that environmental filtering impacts invasion risk when fewer but stronger connections are part of the network. Further, predation is a mechanism of biotic resistance, which can reduce invasion risk, with most pronounced effects predicted in the tropics that decline at higher latitudes. Methods: We examined shipping traffic and predation impact at three coastal bioregions spanning 47-degrees of latitude al range in the Northeast Pacific (Alaska, California, and Panama). We used vessel traffic databases to characterize propagule pressure and construct a worldwide port network of marine shipping routes and ports. Environmental resistance was estimated using temperature and salinity data from donor and recipient regions. We further used standardized predator exposure experiments to quantify predation impact on fouling community biomass as an estimate of potential for biotic resistance. We then expanded on existing models of relative invasion risk to incorporate the probability that propagules will survive predation by local predators and overcome environmental filtering to generate a predicted invasion risk for each port. Results: Environmental filtering in all regions and predation pressure in the tropics worked to reduce the invasion risk, resulting in markedly different cumulative risk profiles over time among regions. Discussion: In an increasingly connected world withmore vessel traffic, our results highlight thatwhile the number and distribution of shipping routes are important to understand risk, abiotic and biotic filters can modify model predictions. [ABSTRACT FROM AUTHOR]

The blue shark Prionace glauca plays a critical role as a predator in marine ecosystems but is threatened by by‐catch. To obtain more precise biological data, a Bayesian approach was used, and 536 vertebrae samples collected during 1 year at the landing stage called "Playita Mía" Manta, Ecuador, were analysed. The objective was to estimate the age and growth parameters of the species. The size of the specimens varied between 116 and 310 cm in total length (TL). Using a Bayesian approach based on the Markov Chain Monte Carlo (MCMC) method, growth parameters were evaluated. The von Bertalanffy model was the one that best fitted the data and provided more adequate estimates (females: L∞ = 325.50 cm, L0 = 53.23 cm, and k = 0.12 years; males: L∞ = 331.47 cm, L0 = 51.59 cm, k = 0.12 years −1; combined sexes: L∞ = 329.65 cm, L0 = 53.64 cm, k = 0.11 year−1). The results indicated that females and males have a similar growth, and that the species has a slow growth. Further studies using multi‐model Bayesian approaches and covering a broader range of sizes in the Pacific Ocean are suggested. These studies will provide crucial information for the management and conservation of this species. [ABSTRACT FROM AUTHOR]

Representationalists hold that perceptual experience is a conscious representational state with content, something which is accurate or inaccurate in certain conditions. The most common version of Representationalism takes perceptual content to be singular in the object-place and otherwise consisting of attribution of properties (Singularism/Attributionism). Schellenberg has recently developed a version on which perceptual content is singular even in the property-place in containing a de re mode of presentation of a property-instance (Particularism). In this paper, I show that Particularism faces a version of the problem of the Unity of Perceptual Content. Namely, its supporters haven't told us how objects can be bound together with property-instances into a content such that it represents them and has accuracy-conditions. Furthermore, I argue that Particularists face an in-principle obstacle in solving it. In contrast, Attributionists can solve the problem and that establishes their view as the only game in town. [ABSTRACT FROM AUTHOR]

Identifying the general patterns of biogeography is vital for a better understanding of biological communities over space. However, there is a lack of well-understood biogeographic patterns of microbial communities in pelagic ecosystems. In this study, we simultaneously investigated archaeal, bacterial and protist communities using metabarcoding in the deep Pacific Ocean. Our results showed that archaea, bacteria and protists shared a depth–decay relationship of community similarity, indicating a decrease in community similarity with increasing differences in water depth. Environmental factors were more important than water depth in shaping this relationship, indicating that the sinking process, compared to environmental conditions, might be relatively minor in driving community variations across water columns. Our study suggests that the depth–decay relationship should be primarily examined in field investigations to better interpret the vertical dynamics of marine microbial communities, and more efforts are required to determine the mechanism underlying this important relationship. [ABSTRACT FROM AUTHOR]

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A lack of natural resources drives the oil dependency in Pacific Island Countries and Territories (PICTs), hampering energy security and imposing high electricity tariffs in the region. Nevertheless, the Western Equatorial Pacific is known for its large Sea Surface Temperature (SST) and deep-sea water (DSW) temperature difference favorable for harvesting thermal energy. In this study, we selected 18 PICTs in the western Equatorial Pacific to estimate Annual Energy Production (AEP) for a 1 MW class Ocean Thermal Energy Conversion (OTEC) plant. We combined the DSW temperature from the mean in situ Argo profiles and 1 km resolution satellite SST data to estimate the thermal energy resource resolving the fine features of the island coastline. Furthermore, the twenty-year-long SST dataset was used to analyze the SST variability. The analysis showed that Equatorial islands and Southern islands have the highest inter-annual variability due to El Nino Southern Oscillation (ENSO). The power density varied from 0.26 to 0.32 W/m2 among the islands, with the lowest values found for the southernmost islands near the South Equatorial Countercurrent. Islands within the South Equatorial Current, Equatorial Undercurrent, and North Equatorial Countercurrent showed the highest values for both power density and gross power. Considering a 1 MW class OTEC plant, Annual Energy Production (AEP) in 2022 varied from 7 GWh to 8 GWh, with relatively low variability among islands near the Equator and in low latitudes. Considering the three variables, AEP, SST variability, and distance from the shore, Nauru is a potential candidate for OTEC, with a net power of 1.14 MW within 1 km from the shore. [ABSTRACT FROM AUTHOR]

Diatoms are key primary producers across marine, freshwater, and terrestrial ecosystems. They are responsible for photosynthesis and secondary production that, in part, support complex food webs. Diatoms can produce phytochemicals that have transtrophic ecological effects which increase their competitive fitness. Polyunsaturated aldehydes (PUAs) are one class of diatom-derived phytochemicals that are known to have allelopathic and anti-herbivory properties. The anti-herbivory capability of PUAs results from their negative effect on grazer fecundity. Since their discovery, research has focused on their production by pelagic marine diatoms, and their effects on copepod egg production, hatching success, and juvenile survival and development. Few investigations have explored PUA production by the prolific suite of benthic marine diatoms, despite their importance to coastal trophic systems. In this study, we tested eight species of benthic diatoms for the production of the bioactive PUAs 2,4-heptadienal, 2,4-octadienal, and 2,4-decadienal. Benthic diatom species were isolated from the Salish Sea, an inland sea within the North Pacific ecosystem. All species were found to be producers of at least two PUAs in detectable concentrations, with five species producing all three PUAs in quantifiable concentrations. Our results indicate that production of PUAs from Salish Sea benthic diatoms may be widespread, and thus these compounds may contribute to benthic coastal food web dynamics through heretofore unrecognized pathways. Future studies should expand the geographic scope of investigations into benthic diatom PUA production and explore the effects of benthic diatoms on benthic consumer fecundity. [ABSTRACT FROM AUTHOR]

The yellowfin tuna represents a significant fishery resource in the Pacific Ocean. Its resource endowment status and spatial variation mechanisms are intricately influenced by marine environments, particularly under varying climate events. Consequently, investigating the spatial variation patterns of dominant environmental factors under diverse climate conditions, and understanding the response of yellowfin tuna catch volume based on the spatial heterogeneity among these environmental factors, presents a formidable challenge. This paper utilizes comprehensive 5°×5° yellowfin tuna longline fishing data and environmental data, including seawater temperature and salinity, published by the Western and Central Pacific Fisheries Commission (WCPFC) and the Inter-American Tropical Tuna Commission (IATTC) for the period 2000–2021 in the Pacific Ocean. In conjunction with the Niño index, a multiscale geographically weighted regression model based on geographically weighted principal component analysis (GWPCA-MGWR) and spatial association between zones (SABZ) is employed for this study. The results indicate the following: (1) The spatial distribution of dominant environmental factors affecting the catch of Pacific yellowfin tuna is primarily divided into two types: seawater temperature dominates in the western Pacific Ocean, while salinity dominates in the eastern Pacific Ocean. When El Niño occurs, the area with seawater temperature as the dominant environmental factor in the western Pacific Ocean further extends eastward, and the water layers where the dominant environmental factors are located develop to deeper depths; when La Niña occurs, there is a clear westward expansion in the area with seawater salinity as the dominant factor in the eastern Pacific Ocean. This change in the spatial distribution pattern of dominant factors is closely related to the movement of the position of the warm pool and cold tongue under ENSO events. (2) The areas with a higher catch of Pacific yellowfin tuna are spatially associated with the dominant environmental factor of mid-deep seawater temperature (105–155 m temperature) to a greater extent than other factors, the highest correlation exceeds 70%, and remain relatively stable under different ENSO events. The formation of this spatial association pattern is related to the vertical movement of yellowfin tuna as affected by subsurface seawater temperature. (3) The GWPCA-MGWR model can fully capture the differences in environmental variability among subregions in the Pacific Ocean under different climatic backgrounds, intuitively reflect the changing areas and influencing boundaries from a macro perspective, and has a relatively accurate prediction on the trend of yellowfin tuna catch in the Pacific Ocean. [ABSTRACT FROM AUTHOR]

Islands had an important role in the first circumnavigation expedition undertaken by Magellan and Elcano. A global history that focuses on islands is necessary, one that no longer places island communities into the marginalized position they are assigned in alleged general histories. Meanwhile, the issue of the island must be approached individually. Islands have historically had features marked by their insularity, which is why, as subjects and objects of research within general historical processes, they sometimes require different interpretations. The Magellan expedition landed on a multitude of islands and sighted many others – we do not know exactly how many. An important fact to keep in mind is that the Capitulations between Magellan and Charles I stipulated that if Magellan discovered more than six islands, he had the right to keep two, act as their governor and enjoy the income from them. In addition, there were many instances of desertion among the expedition members who preferred to stay on those islands.

Throughout the western tropical Pacific Ocean, eddies and currents play an important role in biogeochemical cycling. Many studies have investigated the effects of hydrography on vertical patterns of picophytoplankton and heterotrophic bacterial abundance in mesoscale eddies. There is a lack of field observations to determine what impact dynamic hydrological systems of eddies have on prokaryotic community activity (growth and mortality rates). An objective of this study was to examine how anticyclonic eddies influence picoplankton abundance and activity (growth and mortality rates). To meet this purpose, heterotrophic bacterial and picophytoplankton growth and mortality rates were examined by modified dilution experiments conducted at the surface, deep chlorophyll maximum (DCM), and 200 m depth outside (OE) and inside of warm eddies core (EC) in the west Pacific Ocean. A high heterotrophic bacterial grazing rate was found in the EC region in the present study. Furthermore, the picophytoplankton grazing rate in EC was frequently greater than the grazing rate in OE. Furthermore, the higher grazing rates in the EC region cause a lower proportion of viral lysis to account for heterotrophic bacteria and picophytoplankton mortality. The results of our experiments suggest that downwelling in EC might increase picophytoplankton growth and grazing rates, increasing the carbon sink in the warm eddy and potentially increasing ocean carbon storage.

Nowadays, numerous governments have instituted diverse regulatory frameworks aimed at fostering the assimilation of sustainable energy sources characterized by reduced environmental footprints. Solar, wind, geothermal, and ocean energies were subject to extensive scrutiny, owing to their ecological merits. However, these sources exhibit pronounced temporal fluctuations. Notably, ocean dynamics offer vast energy reservoirs, with oceanic waves containing significant amounts of energy. In the Central American Pacific context, the exploration of wave energy resources is currently underway. Accurate numerical wave models are required for applied studies such as those focused on the estimation of exploitable wave power; and even more so in Central American region of the Pacific Ocean where existing numerical models simulations have so far relied on coarse resolution and limited validation field data. This work presents a high-resolution unstructured wave hindcast over the Central American Pacific region, implemented using the third-generation spectral wave model WAVEWATCH III over the period between 1979 and 2021. The results of the significant wave height have been bias-corrected on the basis of satellite information spanning 2005 to 2015, and further validation was performed using wave buoy and acoustic Doppler current profiler (ADCP) records located in the nearshore region of the Central America Pacific coast. After correction and validation of the wave hindcast, we employed the dataset for the evaluation and assessment of wave energy and its possible exploitation using different wave energy converters (WECs). This evaluation addressed the need to diverse the energy portfolio within the exclusive economic zones of Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama, Colombia, and Ecuador in a sustainable manner. Moreover, a comprehensive analysis was carried out on the advantages of harnessing wave energy, juxtaposed with the imperative of regulatory frameworks and the current dearth of economic and environmental guidelines requisite for development within the region.