The La Pérouse seamount (60 m depth) has so far been poorly studied despite it being a short distance (160 km) from Réunion Island. As part of the MADRidge project, a multidisciplinary cruise was conducted to evaluate the effect of this shallow seamount on the local hydrology and ecology. Current measurements, temperature and chlorophyll-a profiles, and mesozooplankton and micronekton samples were

The northern Bering Sea and Chukchi Sea represent the gateway from the Pacific to the Arctic. This contiguous marine system encompasses one of the largest continental shelves in the world and serves as the sole point of connection between the North Pacific and Arctic Ocean. This region has unique attributes and complex dynamics, driven by the convergence of distinct water masses, dynamic currents,

A temperature and salinity hydrographic profile climatology is assembled, evaluated for data quality, and analyzed to assess changes of the Bering and Chukchi Sea continental shelves over seasonal to century-long time scales. The climatology informs description of the spatial distribution and temporal evolution of water masses over the two shelves, and quantification of changes in the magnitude and

Aerosol optical depth (AOD), black carbon (BC) mass concentration, aerosol size, along with wind parameters, were derived during Southern Ocean expeditions (SOE) 7 and 8 carried out in austral summer of 2013 and 2015, with an aim to analyse the effect of aerosol on incoming solar radiation. The data were complemented with trace metals from aerosol samples of SOE-6 conducted in 2012. The AOD spectra

The Southern Ocean ecosystem is thought to be experiencing a long-term increase in Salpa thompsoni. Uncertainty surrounds the environmental drivers behind variable S. thompsoni abundances, particularly within the East Antarctic region. In this study, S. thompsoni populations were sampled in the Indian Sector of the Southern Ocean, as part of the January–February 2016 Kerguelen Axis voyage. These recent

The influence of environmental factors on the horizontal community structure of zooplankton over the southern Kerguelen Plateau was investigated during summer in 2016. Zooplankton abundance ranged from 1490 to 363,484 ind. 1000 m-3, with highest numbers observed in the eastern and central areas. Based on cluster analysis the zooplankton were divided into six groups (A−F), and these were only distinguished

Fin whales (Balaenoptera physalus) are common summer visitors to the Pacific Arctic, migrating through the Bering Strait and into the southern Chukchi Sea to feed on seasonally-abundant prey. The abundance and distribution of fin whales in the Chukchi Sea varies from year-to-year, possibly reflecting fluctuating environmental conditions. We hypothesized that fin whale calls were most likely to be detected

To better understand habitats of larval Pacific bluefin tuna (PBT; Thunnus orientalis) in the nursery grounds, the vertical distribution of larval PBT was collected using a 1-m2 Tucker trawl and a 3.14-m2 ring net at depths of 0, 10, 20, and 30 m during the spawning seasons of 2016 and 2017. Most of the larvae in the Japan Sea (756 of 938 individuals) were collected from the surface layer using a ring

We investigated the pelagic habitat requirements of Arctic larval fish and the effects of interannual variability of ocean conditions on their distribution. We examined the distribution of larval Arctic cod, Bering flounder, yellowfin sole and capelin in the Chukchi and northern Bering seas during two years with different oceanographic conditions. We found that despite marked changes in water mass

We describe the distribution, abundance and growth of the paralarvae and juveniles of the glass squid Galiteuthis glacialis which were collected from tows conducted at 500 m depth in Prydz Bay, Antarctica by using an Issacs Kidd Midwater Trawl (IKMT). Paralarvae occurred in an area from 57° S to 65°30ʹ S and 57°–66° E. Early juveniles co-occurred with paralarvae at 57°–65° 30′ S and 57° 37′ E to 64°

Annual phytoplankton blooms on the northern region of the Kerguelen Plateau fuel a productive food web that supports highly valuable commercial fisheries for Patagonian toothfish (Dissostichus eleginoides) and mackerel icefish (Champsocephalus gunnari). The food web on the plateau is understudied in comparison to other regions of the Southern Ocean. Major linkages and energy pathways have not been

The biological carbon pump has been estimated to export ~5–15 Gt C yr−1 into the deep ocean, and forms the principal deep-sea food resource. Irregular, intense pulses of particulate organic carbon (POC) have been found to make up about one-third of the overall POC fluxes at a long-term deep-sea research station influenced by coastal upwelling of the California Current, Station M (34°50′N, 123° W, 4000 m

We evaluate a recent region-specific model of export production (Kelly et al., 2018) and some similar fits to in situ data for the California Current Ecosystem using satellite data. The model is a simple linear function of net primary productivity (NPP): Export = 0.08 × NPP + 72 where EF is export flux in mg C m−2 d−1. We confirm that contrary to several global algorithms export efficiency (e-ratio = export/primary

This study examines the applicability of the two-component mixing model in one dimension (depth) to published depth profiles of DOC concentrations and Δ14C values from hydrographic Station M (34°50′N, 123°00′W). We have rederived the two-component model assuming DOC exhibits stable conservative tracer properties and compared it to a model that includes reactivity and radioactive decay. We used 14C∗

High-temporal-resolution views of particle flux to the abyssal benthic boundary layer are provided for an eight-month period (October 2014–June 2015) at the long-term monitoring site Station M within the California Current ecosystem. Contributions of fecal pellets and aggregates to particulate organic carbon (POC) flux at 3900 m depth were estimated based on optical sediment trap (Sedimentation Event

The sequestration of carbon in the deep ocean relies on the export of sinking particulate organic matter (POM) originating in the surface waters and its attenuation by organisms that reprocess and repackage it. Despite decades of research, predicting the variability of POM to the deep ocean remains difficult as there is still a gap in the knowledge as to which and how organisms control or influence

Deep-sea currents in the Northeast Pacific Ocean are examined using observations at Station M, located on the abyssal plain 220 km offshore of central California. Collected near the seabed at ~4000 m depth from October 2014–October 2018, the current meter observations supplement long-term investigations of deep-sea benthic ecology at this site. To investigate mechanisms for variability at different

Gelatinous zooplankton are prominent fauna in the deep ocean, especially in the water column associated with the sea floor. This interface zone, the benthic boundary layer, is critical to biogeochemical exchanges between pelagic and benthic communities. A conspicuous member of this benthic boundary layer community in the abyssal Northeast Pacific (Sta. M; 4000 m depth) is the hydrozoan medusa, Benthocodon

The demersal ichthyofauna at the abyssal Station M at 4100 m depth in the NE Pacific Ocean (34°50′N, 123° 00′W) has been sampled from 1989 onwards using a combination of techniques; baited traps, long lines, otter trawls, towed camera sledge, remotely operated vehicles (ROV), human occupied vehicle (Alvin), benthic long-term time lapse camera and baited camera landers. The fish fauna is dominated by

Ecological and behavioral data on mobile, low density, benthopelagic animals is difficult to collect in the abyssal environment. However, these species occupy an important position in the abyssal food chain. At-depth ROV-mounted echosounder studies provide a powerful tool to gather in-situ information on abyssal benthopelagic assemblages and discern their distribution, behavior and habitat associations

A time series study from 1989 to 2017 indicates that, increasingly, carbon export to abyssal sediments in the California Current Ecosystem (CCE), 220 km west of the central California coast (Sta. M), occurs as rapidly sinking pulses of particulate organic carbon (POC). Nearly continuous sediment trap collections confirm that POC export to 3400 m increased significantly after 2011 with carbon attenuation

Biological communities on the abyssal plain are largely dependent on detritus from the surface ocean as their main source of energy. Seasonal fluctuations in the deposition of that detritus cause temporal variations in the quantity and quality of food available to these communities, altering their structure and the activity of the taxa present. However, direct observations of energy acquisition in

Benthic foraminifera are an abundant and important component of modern and ancient deep-sea ecosystems, and these single-celled organisms generate a fossil record that facilitates the assessment of paleoceanographic changes through time. Despite recent advances in taxonomic and ecological information about deep-sea foraminifera, many basic questions remain, requiring a better understanding of ecological

Feeding, burrowing, locomotion and death of larger organisms can significantly modify the appearance, texture and habitat conditions of the sediment surface. Such modifications create visible biogenic structures and associated microhabitats, which may have negative and/or positive effects on small-sized benthic communities. A series of dives with the submersible ALVIN was undertaken at the long-term

Megafaunal seafloor assemblages on the Monterey Fan in the NE Pacific (Station M, 4000 m depth) were studied between 2006–2018 using remotely operated vehicles (ROVs) as part of a continuing time-series study that began in 1989. Since 2006 we identified nearly 120,000 individual animals representing over 142 morphospecies, and observed continuous changes in the megafaunal assemblage. This study, which

Time-lapse photography provides a view of the seafloor at timescales that make it possible to recognize behaviors and activity of often slow-moving abyssal fauna. Most behavioral studies have focused on mobile animals; sessile benthic fauna have largely been overlooked. We combed through 30 years of time-lapse camera data from Station M, a long-term study site on the abyssal plain off the coast of

Constraining seafloor carbon stocks and flows, and their links to biodiversity, remains a major global challenge, particularly in the deep ocean. We examine the density, biomass, respiration, and species richness size spectra of polychaetes from a time-series study (1991–2011) in the abyssal NE Pacific (Station M, 35°N, 123°W, 4000 m water depth). The spectra met the predictions of the metabolic theory

Antarctic lanternfish (Electrona antarctica) is the dominant mesopelagic fish species in the Southern Ocean. It is the most common myctophid occurring south of the Antarctic Polar Front, and an important component of Southern Ocean food webs, both as a zooplankton predator and as a major prey item for higher predators. Despite its importance, there are major gaps in current understanding of the life

The International Indian Ocean Expedition (IIOE) of 1960-1965 brought together scientists of all the major oceanographic nations of the time, as well as small nations from the Indian Ocean region. The Indian Ocean basin and its processes were largely unknown at the time although it was known to feature unusual dynamics resulting from seasonally reversing monsoon winds that significantly affected the

Basic life history parameters of Arctic fishes have not been well characterized for many species in the Chukchi and Beaufort seas. Increasing environmental and anthropogenic changes in the Arctic may impact the biology of Arctic fishes and can best be evaluated if a benchmark is available against which to evaluate future changes in the biology of Arctic fishes. We used data from over 45,000 individual

A global dataset of carbon stable isotope (δ13C) values from yellowfin, bigeye, and albacore tuna muscle tissue (n = 4275) was used to develop a novel tool to infer broad-scale movement and residency patterns of these highly mobile marine predators. This tool was coupled with environmental models and lipid content (C:N ratio) of tuna muscle tissues to examine ocean warming impacts on tuna ecology and

Taxonomic composition, abundance and biological features of micronektonic fish were investigated using pelagic trawls conducted near and over the summits of three seamounts located in the western Indian Ocean (La Pérouse, MAD-Ridge and Walters Shoal). Mesopelagic fish from three families accounted for 80% by number of the total catch (5714 specimens, 121 taxa), namely myctophids (59%), gonostomatids

Aerosols scatter or absorb incoming solar radiation and alter the earth's radiation budget. The Southern Ocean provides an excellent environment to study the natural/background aerosols and teleconnection with other regions of the world through long-range transport. Measurements of Aerosol Optical Thickness (AOT) (in the wavelength range 380–1020 nm) have been carried out during a 10th Southern Ocean

Understanding larval connectivity patterns is critical for marine spatial planning, particularly for designing marine protected areas and managing fisheries. Patterns of larval dispersal and connectivity can be inferred from numerical transport models at large spatial and temporal scales. We assess model-based connectivity patterns between seamounts of the Southwestern Indian Ocean (SWIO) and the coastal

Conservation of marine ecosystems is important for the sustainable utilization of marine resources under environmental changes and anthropogenic impacts. In Japan, fishery management has been based on single-species stock assessments and little attempts have been made to assess and manage the impacts of multi-species multi-gear fisheries except for a few local case studies. In this study, we analyzed

Coccolithophore ecology and biogeography in the Southern Indian Ocean was studied during the austral summer of 2009 (SOE09; late austral summer), 2010 (SOE10; mid-austral summer), and 2012 (ISEA12; early austral summer). During the SOE09 and SOE10, surface water samples (55 and 54 water samples, respectively) were collected from two different transects between Mauritius and Antarctica (~48°E; ~57.3°E);

Seamounts are recognised as hotspots of biodiversity, attracting large numbers of top predators, but the underlying mechanisms are still unclear. We studied mesozooplankton abundance and size distribution at three shallow seamounts (60 m, 240 m and 18 m deep) in the South West Indian Ocean, along a latitudinal gradient (19°S, 27°S and 33°S). Samples were analysed using a ZooScan, allowing the use of

The narrow-barred Spanish mackerel (Scomberomorus commerson) is an economically important fish species in Taiwan. Nevertheless, its reproductive biology in the region is poorly understood. This study provides the first information on the reproductive biology of this species in the central Taiwan Strait. In total, 1031 specimens were collected from January 2016 through August 2017, and the sex ratio

The feeding ecology of Pacific Bluefin tuna (PBT: Thunnus orientalis) larvae collected from two nursery grounds, namely the Japan Sea and the Nansei area (western North Pacific), was evaluated based on gut content analyses using morphological and metagenetic techniques. The PBT larvae were collected at the surface layer (≥30 m depth) in 2016 and 2017, and 172 and 114 individuals from the Japan Sea

The high abundances and high silicification levels of the diatoms Fragilariopsis kerguelensis (O'Meara) Hustedt and Thalassiosira lentiginosa (Janisch) Fryxell make them crucial silica carriers to the Southern Ocean (SO) sea-floor. However, their efficiency as silica vectors to the ocean bottom might be modulated by important variations in their sizes, from ~10 μm to ~100 μm for F. kerguelensis and

Species distribution models (SDMs) are used for a variety of scientific and management applications. For species associated with drifting fish aggregating devices (DFADs), such as tuna, spatial models can help tuna Regional Fisheries Management Organizations (t-RFMOs) understand their habitat characteristics and dynamics. DFADs are monitored and tracked with satellite linked echo-sounder buoys, which

A total of 4.9 million vertical profiles of optical backscattering were measured by airborne lidar in July of 2014 and July of 2017 in the Chukchi and Beaufort seas. We found very different ice conditions in the study area between July 2014 and July 2017, but the characteristics of subsurface plankton layers measured by the lidar and their dependence on ice cover were similar for the two years. In

Picoplankton and nanoplankton community abundances were sampled on and around a seamount located on the Madagascar Ridge, in November 2016. Prochlorococcus, Synechococcus, picoeukaryote and nanoplankton community abundances both on the seamount and in the immediate vicinity (approximately 100 km) surrounding it were analysed using flow cytometry. The original aim of the study was to estimate whether

Published information from the Western Indian Ocean (WIO) and new data from the South West Indian Ocean Ridge, are consolidated and combined to generate an updated biogeography of calanoid copepods. The WIO was divided into 75 5° grid squares, and a similarity matrix between grids was generated on the basis of presence:absence data for more than 172 species. Distinct assemblages are identified that

Benthosema pterotum is one of the most abundant myctophids and an important species link in the food web between producers and consumers in the continental shelf of the southern East China Sea (ECS). This study used R/V Ocean Researcher 1 and 5 to investigate the spatial distribution of B. pterotum larvae and the associated environmental factors affecting the continental shelf of the southern ECS between

The calanoid copepod Calanus finmarchicus is one of the most abundant and ecologically important species of the zooplankton assemblage of the North Atlantic Ocean and occupies a pivotal position in the pelagic food web. This study used metabarcoding analysis (high throughput DNA sequencing of target gene regions) to examine the diversity of the copepod gut content, including both eukaryotic and prokaryotic

The Chukchi Ecosystem Observatory (CEO), a mooring array of subsurface oceanographic instruments, was established on the northeast Chukchi Sea continental shelf to obtain time-series measurements of physical, biogeochemical, and biological parameters. A sequential sediment trap was deployed on a CEO mooring 8 m above seafloor to measure export fluxes of chlorophyll a (chl a), microalgal cells, zooplankton

Salmon aquaculture is in great need of good quality balanced protein and lipid sources, particularly marine omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA), to sustain a further development of the industry. One possibility is to harvest mesopelagic marine layers. Therefore, the current project analysed mesopelagic hauls from three cruises (November 2015 to October 2016) collected from

There is a growing interest in the management of seamounts of the Southwestern Indian Ocean (SWIO) both in waters under national jurisdictions and in the Areas Beyond National Jurisdiction (ABNJ). New scientific knowledge has been gathered through various oceanographic cruises during the past decade, and new agreements are under consideration globally to promote conservation and sustainable use of

Thysanoessa macrura is well adapted to the strong seasonality of the Southern Ocean. A flexible diet, large lipid reserves and a winter reproductive period provide T. macrura with the ability to capitalise on the pulses of primary and secondary reproduction in spring and summer. The population dynamics of T. macrura were examined over the southern Kerguelen Plateau region as part of a large-scale ecosystem

The species occurrence of mesopelagic fish collected in the scattering layers was studied across the Indian Ocean subtropical gyre during the dry season (2015). Ocean eddies can retain zooplankton and plastic debris, and determine biological composition through advection. The conditions inside the gyre were stabilised by low chlorophyll-a concentrations and a deep nutricline. A diverse assemblage of

Fish population processes could exhibit non-stationary behaviour as a stochastic biological process with temporal autocorrelation that may be influenced by environmental changes. Here we developed a Bayesian autoregressive state-space surplus production modelling framework to explore potential non-stationarity in population processes. We then evaluated the consequence of non-stationary population processes

Chum salmon (Oncorhynchus keta) are distributed widely in the subarctic North Pacific. The Japanese stock is maintained by artificial release procedures. Chum salmon, including the Japanese stock, provide important ecosystem services for humans that are related to provisioning, culture and support. These ecosystem services are supported by the supply of prey and habitat that the fish use. We regard

Distribution of micronekton was investigated during early summer of 2013, using data from a cruise covering the central parts of four north Atlantic basins, the Norwegian Sea (NS), Iceland Sea (ICS), Irminger Sea (IRS), and Labrador Sea (LS). Continuous underway acoustics mapped vertical and horizontal distributions, and trawl sampling provided data on biomass and taxonomic composition. The hull mounted

Forage fish are a vital trophic group in marine ecosystems and numerical models, linking plankton with higher trophic levels. The bioenergetics of a key forage fish in eastern Australia, yellowtail scad Trachurus novaezelandiae, was measured using static respirometry and bomb calorimetry to assess their trophic contribution as both predator and prey. The temperature-dependent standard metabolic rate

Cetaceans often inhabit a dynamic ocean environment; therefore, a standard approach to estimating abundance faces the difficult task of discriminating between actual population trends and habitat shifts. In addition, because of the wide distribution of many cetaceans, it is often difficult to survey their entire habitat at one time, which makes it difficult to compare abundance estimates between years

The Arabian Sea is important in global biogeochemistry because of its high rates of primary production, its extensive zone of oxygen depletion and denitrification, and its expected strong response to global warming via ocean-atmosphere feedbacks to monsoon winds and upwelling intensity. Monsoon-driven upwelling leads to higher rates of primary production during the summer. However, the Arabian Sea

The horizontal and vertical movements of two large sunfishes (TL > 200 cm) were investigated using pop-up satellite archival tags off eastern Taiwan in 2017–2018. One tag attached to Mola mola popped-up in the South China Sea after 148 days at-liberty and another on M. alexandrini was recovered after 18 days. The most probable track, estimated by the Kalman filter with matching sea surface temperature

Trends in near-surface currents passing through the southeastern Caribbean are described using ocean reanalysis and a coupled model projection. The decline of Caribbean through-flow is linked with tropical and polar forcing. In the upstream zone, the North Brazil Current shows increasing retroflection as the southern Hadley Cell expands across the equatorial Atlantic. This inhibits northwestward transport

Using Taiwanese longline fishery data, this study investigated the influence of climate variability and environmental conditions in the Indian Ocean on the catch rates and distribution of immature and mature cohorts of yellowfin tuna. The variations in the seasonal distribution of immature and mature cohorts suggest that yellowfin tuna move extensively from the Arabian Sea and Bay of Bengal to the