Cruise Of Research Vessel Research Articles

A 2 °C difference affecting the spatiotemporal distribution of small demersal fish assemblages in shallow tropical and subtropical waters of Western Taiwan

Two OR3 research vessel cruises were conducted at seven nearshore sites from north to south in the western coastal waters off Taiwan in May (late spring) and November (late autumn) 2019 in order to gain insights into the 2 °C difference in the tropical-subtropical fish fauna. Totally, 37 families, 72 genera, and 99 taxas were recorded for the 1809 fishes. Three fish assemblages, the North, South, and Fall-Zhuoshui River (ZRf) groups, were identified as eurythermal, stenothermal, and croaker communities. Their dominants, in rank order, were Tarphops oligolepis, Liachirus melanospilosa, Ostorhinchus fasciatus, and Trachinocephalus myops for the Northern eurythermal group, Arnoglossus tenuis, Eubleekeria splendens, and Ostorhinchus pleuron for the Southern stenothermal group, and Johnius taiwanensis, Chrysochir aureus, and Pennahia macrocephalus for the croaker-ZRf group. Their distribution was markedly correlated with the bottom water temperature, seafloor grain size, and concentration of suspended solids. The influence of a 2 °C difference on the tropical and subtropical demersal fish could indicate how rising temperatures due to climate change are shaping fish communities. The flatfish, Liachirus melanospilos, was distributed northward by 0.5oN and is suggested to be considered as an ecological indicator of the tropicalization of subtropical marine ecosystems in the future.

Shrimp community structure and influence of environmental variables in the East China Sea and Yellow Sea in spring.

Based on data collected from research vessel cruises performed in May 2020 off the East China Sea (ECS) and the southern Yellow Sea (YS) (26°30'-35°00' N, 120°30'-127°00' E), we analyzed the shrimp community and its relationships with environmental variables by using index of relative importance, biodiversity indices, and multivariate techniques. A total of 29 species were recorded, belonging to 11 families and 19 genera. The dominant species were Metapenaeopsis longirostris, Leptochela gracilis, Solenocera melantho, Crangon hakodatei, Parapenaeus fissuroides, Plesionika izumiae, and Trachypenaeus curvirostris, which together accounted for 82.9% of the total biomass and 90.8% of the total abundance of shrimps. Results of Cluster and NMDS analyses showed that three groups were identified for the shrimp community in the ECS and YS in spring, including group A (inshore of northern ECS and YS group), group B (offshore of northern ECS group) and group C (southern ECS group). ANOSIM and SIMPER analysis showed significant differences between group A and B, gourp A and C, and group B and C, with the dissimilarity of 92.2%, 95.8% and 91.6%, respectively. The typical species were T. curvirostris, C. hakodatei, L. gracilis and Palaemon gravieri in group A, and S. melantho in group B, and M. longirostris, P. fissuroides, P. izumiae and Solenocera alticarinata in group C. Significant differences were also detected in biomass, diversity index, species richness index and evenness index among groups, with significantly greater values in group C than those in A and B. Environmental variables and the substrate also displayed significant differences among groups. Results of canonical correspondence analysis showed that bottom temperature, bottom salinity, depth, and the substrate were the main environmental variables affecting spatial structure of shrimp community. Water mass characteristics and substrate type had important influences on the distribution of shrimp community in the ECS and YS in spring.

Ecosystems of Siberian Arctic Seas – 2022: Ecosystem of the Eastern Kara Sea, Ecological Risks Accumulated in the Basin (89 Cruise of Research Vessel “Akademik Mstislav Keldysh”)

89 cruise of R/V “Akademik Mstislav Keldysh” was organized by Shirshov Institute of Oceanology in a frame of the Program “Marine Ecosystems of Siberian Arctic” and was held form 19 September to 10 October 2022. 60 scientists from the institutes of Russian Academy of Sciences, Moscow State University, Moscow Institute of Physics and Technology, VNIRO and MES participated in the cruise. Coordinated hydrophysical, hydrochemical, biooceanological, geochemical research, valuation of greenhouse gases concentration in above-water atmosphere were carried out over the shelf and continental slope of the eastern poorly known part of the Kara Sea. Ecosystem of Blagopoluchiya Bay (Novaya Zemlia) and conditions of disposals of radioactive waste in the bay were in a focus of the research as well.

Microplastics distribution in bottom sediments of the Baltic Sea Proper

An abundance of microplastics particles (0.2–5 mm, MPs) in bottom sediments is analyzed based on 53 samples (3 to 215 m deep) obtained in 8 cruises of research vessels across the Baltic Sea Proper in March–October 2015–2016. MPs content varied between stations from 103 up to 10,179 items kg−1 d.w., with the bulk mean of 863 ± 1371 items kg−1 d.w., showing a statistically significant increase with water depth. As many as 74.5% of MPs are of fibrous shape, followed by films (19.8%) and fragments (5.7%). The distributions of fibres, fragments, films, and different types of natural bottom sediments are significantly different, highlighting the specific behaviour of each of these kinds of bottom deposits. A statistically significant correlation between water depth and fibres content is found. Based on the analysis of oceanographic factors and sedimentological principles, an erosion/transition/accumulation pattern for fibres in the Baltic Sea Proper is outlined. Fibres can be considered as a specific type of “synthetic sediment”, while principles of distribution of other MPs are not yet certain.

Spatiotemporal distribution of shrimp assemblages in the western coastal waters off Taiwan at the Tropic of Cancer, Western Pacific Ocean

Two Ocean Researcher No.3 research vessel cruises were conducted at seven sites set along the western coastal waters off Taiwan in May (late spring) and November (late autumn) 2019, to elucidate the spatiotemporal variation of the benthic shrimp assemblages. Among the 27 recorded shrimp species, the species number was higher in late autumn (20 species) due to the appearance of several oligothermal shrimps, than in late spring (15 species) with only polythermal tropical shrimps. Two shrimp assemblages, the North group and South group, were identified in the nearshore coastal waters off western Taiwan with distinct dominant shrimp species. Their spatiotemporal distribution reflects the large-scale seasonal water temperature variation driven by the cold China Coastal Current (CCC), and the warm Kuroshio Branch Current (KBC) and South China Sea Surface Current (SCSSC), as well as the shrimp preference for sediment grain size. The North group is situated north of Chiku (Qigu) (23°09′N), which is the cold CCC southbound limit in winter, and is composed mainly of subtropical shrimps, dominated by Parapenaeopsis hardwickii and P. sinica. The South group is located south of Jiading (Qieding) (22°52′N), which is annually affected by the warm KBC and SCSSC, heating the water temperature to >25 °C, even in winter, except for January. The South group is composed of mainly tropical shrimps dominated by Metapenaeopsis. palmensis, which cannot live in water temperatures <25 °C. This is the first report of tropical-subtropical shrimp assemblages formed in conjunction with the large-scale variation of the water mass and current-driven sediment grain size on a seasonal and geographical location basis. It is also shown that P. hardwickii made a northward retreat of ca. 0.5oN in the past two decades, and the baseline has been set to study the north-range shift of the tropical shrimps in the future in this location.

Assessment of Atmospheric Reanalyses With Independent Observations in the Weddell Sea, the Antarctic

AbstractSurface layer and upper‐air in situ observations from two research vessel cruises and an ice station in the Weddell Sea from 1992 and 1996 are used to validate four current atmospheric reanalysis products: ERA‐Interim, CFSR, JRA‐55, and MERRA‐2. Three of the observation data sets were not available for assimilation, providing a rare opportunity to validate the reanalyses in the otherwise datasparse region of the Antarctic against independent data. All four reanalyses produce 2 m temperatures warmer than the observations, and the biases vary from +2.0 K in CFSR to +2.8 K in MERRA‐2. All four reanalyses are generally too warm also higher up in the atmospheric boundary layer (ABL), with biases up to +1.4 K (ERA‐Interim). Cloud fractions are relatively poorly reproduced by the reanalyses, MERRA‐2 and JRA‐55 having the strongest positive and negative biases of about +30 % and −17 %, respectively. Skill scores of the error statistics reveal that ERA‐Interim compares generally the most favorably against both the surface layer and the upper‐air observations. CFSR compares the second best and JRA‐55 and MERRA‐2 have the least favorable scores. The ABL warm bias is consistent with previous evaluation studies in high latitudes, where more recent observations have been applied. As the amount of observations has varied depending on the decade, season, and region, the consistency of the warm bias suggests a need to improve the modeling systems, including data assimilation as well as ABL and surface parameterizations.

Complex research during the 33-rd cruise of research vessel “Akademik Nikolaj Strakhov”

The 33rd cruise of the R/V “Akademik Nikolaj Strakhov” was in the Atlantic Ocean and the Baltic Sea, and included a complex of geological, hydrological and hydrochemical works. According to the results of a multibeam echo sounder survey of the bottom, digital models of bottom landscapes were constructed. Using the dredging method, new geological samples were obtained, and the values of geothermal flows in the Atlantic Ocean were measured.

Spatiotemporal Variations in Atmospheric Aerosol Optical Depth along the Route of the 42nd Cruise of RV “Akademik Boris Petrov”

Results of expedition studies of the spatiotemporal variations in the aerosol optical depth (AOD) of the atmosphere during the 42nd cruise of research vessel (RV) “Akademik Boris Petrov” (January 18–March 28, 2017) along the route from Singapore to Kaliningrad (via the Suez Canal) are discussed. It is shown that the highest atmospheric turbidities were observed over the Arabian (due to the outflows of finemode aerosol from Hindustan) and Red (due to the outflows of dust aerosol) Seas, where the average AODs near 0.50 μm was 0.355 and 0.304, respectively. A considerable aerosol turbidity is also a characteristic of the atmosphere in the Strait of Malacca, burdened by aerosol outflows from the direction of Sumatra and western Malaysia (average AOD is 0.262). Different aerosol contents are noted in the neighboring equatorial regions of the Indian Ocean: the AOD in the middle of the ocean, more remote from the contents, was a factor of 1.5–2.0 larger than near Sumatra Island. All the tropical zone of the Indian Ocean is characterized by high values of the Angstrom selectivity exponent (1.08–1.18), indicating a predominant contribution of fine-mode aerosol to the AOD.

Evaluation of four global reanalysis products using in situ observations in the Amundsen Sea Embayment, Antarctica

AbstractThe glaciers within the Amundsen Sea Embayment (ASE), West Antarctica, are amongst the most rapidly retreating in Antarctica. Meteorological reanalysis products are widely used to help understand and simulate the processes causing this retreat. Here we provide an evaluation against observations of four of the latest global reanalysis products within the ASE region—the European Centre for Medium‐Range Weather Forecasts Interim Reanalysis (ERA‐I), Japanese 55‐year Reanalysis (JRA‐55), Climate Forecast System Reanalysis (CFSR), and Modern Era Retrospective‐Analysis for Research and Applications (MERRA). The observations comprise data from four automatic weather stations (AWSs), three research vessel cruises, and a new set of 38 radiosondes all within the period 2009–2014. All four reanalyses produce 2 m temperature fields that are colder than AWS observations, with the biases varying from approximately −1.8°C (ERA‐I) to −6.8°C (MERRA). Over the Amundsen Sea, spatially averaged summertime biases are between −0.4°C (JRA‐55) and −2.1°C (MERRA) with notably larger cold biases close to the continent (up to −6°C) in all reanalyses. All four reanalyses underestimate near‐surface wind speed at high wind speeds (&gt;15 m s−1) and exhibit dry biases and relatively large root‐mean‐square errors (RMSE) in specific humidity. A comparison to the radiosonde soundings shows that the cold, dry bias at the surface extends into the lower troposphere; here ERA‐I and CFSR reanalyses provide the most accurate profiles. The reanalyses generally contain larger temperature and humidity biases, (and RMSE) when a temperature inversion is observed, and contain larger wind speed biases (~2 to 3 m s−1), when a low‐level jet is observed.

Surface pathway of radioactive plume of TEPCO Fukushima NPP1 released &amp;lt;sup&amp;gt;134&amp;lt;/sup&amp;gt;Cs and &amp;lt;sup&amp;gt;137&amp;lt;/sup&amp;gt;Cs

Abstract. 134Cs and 137Cs were released to the North Pacific Ocean by two major likely pathways, direct discharge from the Fukushima NPP1 accident site and atmospheric deposition off Honshu Islands of Japan, east and northeast of the site. High density observations of 134Cs and 137Cs in the surface water were carried out by 17 cruises of cargo ships and several research vessel cruises from March 2011 till March 2012. The main body of radioactive surface plume of which activity exceeded 10 Bq m−3 travelled along 40° N and reached the International Date Line on March 2012, one year after the accident. A distinct feature of the radioactive plume was that it stayed confined along 40° N when the plume reached the International Date Line. A zonal speed of the radioactive plume was estimated to be about 8 cm s−1 which was consistent with zonal speeds derived by Argo floats at the region.

Invertebrate Fauna Associated with Floating Sargassum horneri (Fucales: Sargassaceae) in the East China Sea

The invertebrate fauna associated with floating Sargassum horneri (Turner) C. Agardh, 1820 in the East China Sea was investigated in terms of ecology and biogeography. Floating algal rafts consisting of only S. horneri were collected at 16 stations in the East China Sea during a cruise of research vessel (R/V) Tansei-Maru in February, 2011. A total of 53 rafts were obtained for faunal investigations at 14 of the 16 stations. In addition to fish eggs, 10 invertebrate taxa were found on the floating algae. Of the collected phytal animals, harpacticoid copepods were most abundant in terms of number (80%), followed by cirripedes (15%), amphipods (4%), and others (1%). The faunal diversity on the algae was correlated to the algal weight. The faunal diversity differed significantly between stations and was highest in the northernmost part of the East China Sea. Density and abundance of animals were highest in areas close to the Kuroshio Current. Considering the direction of flow of the Kuroshio Current and the density of cirripedes immigrating from the surrounding water onto the floating algae, most of the floating S. horneri possibly originated in the southern part of the East China Sea. On the other hand, the Sargassum rafts collected in the northernmost part of the East China Sea could have originated from the coast of eastern China. Most of the animals found on the floating Sargassum were pelagic taxa that complete their life cycles on the rafts in situ. Typical coastal animals, including gammaridean and caprellidean amphipods, tanaidaceans, nematodes, gastropods, polychaetes, halacarid mites, bryozoans, and hydrozoans, were also obtained from the floating Sargassum , but only occasionally and their densities were quite low. These facts suggest that dispersal events among benthic habitats via Sargassum rafts are relatively rare.

Miocene volcanism of the Ninetyeast Ridge

The East Indian or Ninetyeast Ridge is one of the most unique and enigmatic structures of the oceanic bottom. It is characterized by a linear shape and extends in the meridional direction via the eastern part of the Indian Ocean for almost 5000 km and is approx� imately 200 km wide (Fig. 1). The ridge was discovered in the 1920s and first studied in detail in 1963 during the R/V Vityaz scientific expedition. In subsequent years, geological–geophysical studies of the ridge were conducted in cruises of research vessels from the Shir� shov Institute of Oceanology, RAN [1] and other Rus� sian and foreign scientific organizations. Most of the geological–geophysical data were obtained there in the 1970s–1980s.Since that time, the scientific equip� ment and study methods have become substantially better. Despite the sufficient knowledge of the ridge structure owing to numerous oceanological expedi�

Environmental genotoxicity and cytotoxicity in the offshore zones of the Baltic and the North Seas

Micronuclei (MN), nuclear buds (NB) and fragmented-apoptotic cells (FA) were analyzed in mature peripheral blood and immature cephalic kidney erythrocytes of flounder ( Platichthys flesus), dab ( Limanda limanda) and cod ( Gadus morhua) from 12 offshore sites in the Baltic Sea (479 specimens) and 11 sites in the North Sea (291 specimens), which were collected during three research vessel cruises in December 2002, 2003 and in September 2004. The highest levels of environmental genotoxicity (frequencies of MN up to 0.5‰, NB – up to 0.75‰) and cytotoxicity (FA – up to 0.53‰) were observed in flatfishes from areas close to oil and gas platforms in the North Sea and in zones related to the extensive shipping and potentially influenced by contamination from large European Rivers (Elbe, Vistula, Oder). In dab from the offshore zones of the North Sea, the levels of nuclear abnormalities were higher as compared to those in dab from the Baltic Sea. Responses in immature kidney erythrocytes were higher than in mature erythrocytes from peripheral blood. MN frequency lower than 0.05‰ (the Baltic Sea) and lower than 0.1‰ (the North Sea) could be suspected as a reference level in the peripheral blood erythrocytes of flatfish.

Relationship between the Beam Attenuation Coefficient and the Concentration of Suspended Matter in Black-Sea Waters

By using the results of simultaneous measurements of the beam attenuation coefficient and the concentration of suspended matter in water samples, we deduce the relationships between these parameters for wavelengths of 640, 660, and 677 nm. The proposed formulas are used for the evaluation of the concentration of suspended matter according to the data of optical measurements performed in cruises of research vessels. We present two maps of the distribution of suspended matter plotted for the north part of the sea in November–December 1991 and for the south part of the sea in July 1992.

The prevalence of Hematodinium in Nephrops norvegicus from the western Irish Sea

Infection of Nephrops norvegicus by a dinoflagellate parasite belonging to the genus Hematodinium, is reported in populations of Nephrops from the Irish Sea. Diseased animals are recognized by an opaque vivid body colour and high densities of parasites in the haemolymph. Infection causes a general morbidity of the host along with a reduction in swimming performance, which eventually leads to the death of the host lobster. Research vessel cruises performed over the period 1994–2001 have shown Hematodinium to occur in populations of Nephrops from the Irish Sea throughout this period. High infection prevalence during the month of April and negligible levels during October agree with published data on seasonal infection levels in Scottish Nephrops stocks. Data on spatial and temporal infection prevalence are presented for the first time for the Irish Sea and show variation between stations and between years. Mean infection prevalence peaked at 18% of captured Nephrops during April 1996 and was followed by a downward trend to 2001. Infection predominates in small Nephrops (&lt;30 mm carapace length) and in females is normally associated with immature animals. Although a positive correlation with seawater salinity was noted, preliminary analysis did not show a relationship between prevalence and other environmental factors.

Validation of the ATSR in Australian Waters

The Along Track Scanning Radiometer (ATSR) was launched on the ERS-1 satellite on 17 July 1991. During the following six months, a concentrated effort was made to validate the sea surface temperature (SST) derived from data supplied by this new generation radiometer. Ship and aircraft radiometers collected “ground truth” data that were coincident with ATSR measurements and thus allowed a comparison of the surface and space measurements. A large proportion of the early validation data was obtained during four research vessel cruises in Australian waters, and a detailed analysis of those results is presented here. Ancillary data were collected to support the shipborne radiometer measurements and to allow further analyses beyond the important validation task. These data included the standard surface meteorological data, bulk SST, and, in most cases, ship-launched radiosondes. Four different algorithms derived using a theoretical atmospheric transmission model were applied to the ATSR data to provide estimates of SST, and these estimates were compared to the surface-based measurements. All the algorithms gave reasonable agreement with each other as well as agreement with the surface data. The algorithm using all six infrared measurements gave the lowest standard deviation but showed a warm bias of 0.2 K when compared to the temperature of the skin layer of the ocean. The validation results show that the ATSR instrument can provide SST within the design accuracy of 0.3 K. The results of the validation presented here are in good agreement with those reported elsewhere using other datasets. Further improvements in SST accuracy, perhaps to 0.2 K, may be expected with a more rigorous analysis of the data.

THE USE OF CAESIUM-137 TO MEASURE DISPERSION FROM DISCHARGE PIPELINES AT NUCLEAR SITES IN THE UK.

The Ministry of Agriculture, Fisheries and Food has been monitoring the concentrations of caesium-137 in sea water in the vicinity of nuclear sites since 1962. The concentrations measured are attributable to liquid discharge from the nuclear sites, superimposed on a background which may compromise the effects of distant discharges from BNFL Sellafield and fallout from nuclear weapons testing, and in recent years, from Chernobyl. A method of estimating the initial dispersion in the immediate area of a nuclear site, by calculating the concentration of caesium-137 in sea water for a unit rate of introduction in liquid effluent, is described and illustrated by a number of examples. Allowances are made for the background, which has been deduced from measurements of radiocaesium taken at remote positions, mainly during research vessel cruises. (author).

Spatial and temporal variance of hydrocarbon pollution data in a coastal river-influenced sedimentary system

The statistical significance of the coastal pollution mapping studies based on the sedimentary composition of aliphatic, chlorinated, and aromatic hydrocarbons has been evaluated from the replicate sampling (four research vessel cruises) and analysis of six coastline perpendicular transects, each situated in front of a river mouth. The analysis of variance has shown that this type of sediment network affords the recognition of the main coastal pollution discharge sites at the 1% confidence level, but it is not useful for tracing their area of influence

Parkinson's Petrel Distribution and Foraging Ecology in the Eastern Pacific: Aspects of an Exclusive Feeding Relationship with Dolphins

During 28 research vessel cruises in the eastern tropical Pacific Ocean from 1976 through 1990, Parkinson's Petrels (Procellaria parkinsoni) were observed near shore from southern Mexico (ca. 15°N) to northern Peru (ca. 5°S), and along a broad seaward extension that continued west of the Galápagos Islands to 110°W. Parkinson's Petrels regularly associated with dolphins: of the 618 petrels observed, 469 (76%) were associated with 10 species of dolphins, on 55 occasions, with 1 to 300 petrels present. They occurred mostly with two rare dolphin species: the melon-headed whale (Peponocephala electra) and the false killer whale (Pseudorca crassidens). This appeared to be a largely obligatory foraging relationship for Parkinson's Petrels. Associations with other dolphin species occurred primarily when those species also associated with melon-headed and false killer whales. Parkinson's Petrels avoided a common and widespread, multi-species feeding assemblage which consisted of a diverse, fast-moving group of seabirds, spotted and spinner dolphins (Stenella attenuata and S. longirostris), and tuna, all of which feed on live prey forced to the surface. The lumbering Parkinson's Petrels appeared ill-equipped to take such prey. In contrast, melon-headed and false killer whales apparently fed by dismembering large prey below the surface and so, provided feeding opportunities for a scavenging bird with diving capabilities. Among eastern tropical Pacific (ETP) seabirds, Parkinson's Petrels alone are adapted for recovering food scraps well below the surface. Parkinson's Petrels appear to be more dependent on marine mammals for foraging than any other species of seabird studied and feed diurnally more than was previously thought.

Bottom topography to the west of the Wyville-Thomson Ridge

Soundings collected during research vessel cruises in the region immediately to the west of the Wyville-Thomson Ridge permit the topography to be described in detail, especially with reference to the inflow to the Rockall Trough of Norwegian Sea Deep water. Topography directs the densest water towards an isolated deep of over 1700 m depth, but water can only flow from this to the south across a sill at 1300 to 1360 m, or to the northwest above 1110 m. A number of modifications to existing topographic charts of the area are noted.