Deep-Sea Research Part I-Oceanographic Research Papers最新文献

{"title":"One new genus and five new species of deep-sea bryozoans from the subantarctic Southwest Atlantic","authors":"Juan López-Gappa,&nbsp;María G. Liuzzi","doi":"10.1016/j.dsr.2024.104292","DOIUrl":"https://doi.org/10.1016/j.dsr.2024.104292","url":null,"abstract":"<div><p>In this study we introduce one new genus and five new species of cheilostome bryozoans based on material collected mainly at bathyal depths in the Subantarctic Southwest Atlantic by the vessels ARA <em>Bahía Blanca</em>, BO <em>Puerto Deseado</em> and RV <em>Meteor</em>. <em>Bathyanasca incubatrix</em> gen. nov., sp. nov., <em>Chondriovelum perforatum</em> sp. nov., <em>Aspidostoma adeoniforme</em> sp. nov., <em>Talivittaticella bathyalis</em> sp. nov. and <em>Turritigera formidabilis</em> sp. nov. are described and illustrated. <em>Bathyanasca incubatrix</em>, characterized by the lack of ovicells and the incubation of embryos within the autozooidal cavity, is tentatively classified in the family Calloporidae. Present results contribute to support the hypothesis of close faunal affinities between Antarctica and relatively deep areas around southern South America.</p></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140350621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal and vertical variations in carbon flux and export of zooplankton fecal pellets in the western South China Sea","authors":"Junyuan Cao,&nbsp;Zhifei Liu,&nbsp;Baozhi Lin,&nbsp;Yulong Zhao,&nbsp;Jiaying Li,&nbsp;Hanxiao Wang,&nbsp;Xiaodong Zhang,&nbsp;Jingwen Zhang,&nbsp;Hongzhe Song","doi":"10.1016/j.dsr.2024.104283","DOIUrl":"https://doi.org/10.1016/j.dsr.2024.104283","url":null,"abstract":"<div><p>The enhancement of particulate organic carbon transfer to the deep sea by zooplankton fecal pellets constitutes a crucial component of the marine biological carbon pump. Here, we investigated time-series variations in characteristic and flux of zooplankton fecal pellets at different water depths of two sediment-trap mooring stations from May 2021 to May 2022 in the western South China Sea. The results show that numerical fluxes of fecal pellets were 0.75 ± 0.60 × 10⁴, 0.63 ± 0.63 × 10⁴, and 0.38 ± 0.29 × 10⁴ pellets m⁻² d⁻¹ at 500 m, 1170 m, and 1380 m water depth, respectively, corresponding to their carbon fluxes of 0.10 ± 0.06, 0.09 ± 0.04, and 0.10 ± 0.04 mg C m⁻² d⁻¹. Both numerical and carbon fluxes of fecal pellets exhibited clear seasonal variations, with two peaks occurred in August and early November at all water depths. The fecal pellets have distinct morphological types (spherical, cylindrical, and ellipsoidal) and their contributions to the numerical and carbon fluxes were different. At all water depths, ellipsoidal and spherical pellets accounted for 96.0% of the numerical flux and 72.1% of the carbon flux. Cylindrical pellets were rare in quantity, accounting for 4.0% of numerical flux, but their carbon contribution accounted for 27.9% of the total fecal pellet carbon flux. The proportional fractions of zooplankton fecal pellets contributed to the overall particulate organic carbon from 0.7% to 28.2% in the western South China Sea, and fell in a reasonable range around the world. Multiple mechanisms, including East Asian monsoon climate and zooplankton community structure may be responsible for the production and fate of fecal pellets as well as their contribution to the settling particulate organic carbon.</p></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140332933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemical indications of hydrothermal fluid through sediments within the Geolin Mounds and Mienhua Volcano hydrothermal fields, southernmost Okinawa Trough","authors":"Feng-Hsin Hsu ,&nbsp;Chih-Chieh Su ,&nbsp;Yu-Shih Lin ,&nbsp;Hsiao-Fen Lee ,&nbsp;Mei-Fei Chu ,&nbsp;Tefang Lan ,&nbsp;Shein-Fu Wu ,&nbsp;Song-Chuen Chen","doi":"10.1016/j.dsr.2024.104293","DOIUrl":"https://doi.org/10.1016/j.dsr.2024.104293","url":null,"abstract":"<div><p>This study focused on the chemistry of sedimentary pore fluids to clarify hydrothermal fluid migrating within sediments at the Geolin Mounds (GLM) and Mienhua Volcano (MHV) hydrothermal fields, southernmost Okinawa Trough, where are characterized by covering of thick sediment. The significant downward decrease in Mg²⁺ (low to 23.3 mmol L⁻¹) and concurrent increase in Li⁺ (up to 2,269 μmol L⁻¹) in sedimentary pore fluids implied a substantial influence of hydrothermal fluid, which might be associated with high-temperature (&gt;350 °C) rock/sediment-fluid interaction. The best fitting of the 1-D advection-diffusion equation to pore-fluid Cl⁻, Mg²⁺, and Li⁺ concentrations further evidenced the upward hydrothermal through sediments with rates of 0.13 ∼ 124 cm yr⁻¹. The apparently Cl-depleted and slightly Cl-enriched pore fluids in the GLM and MHV hydrothermal fields supported the occurrence of subseafloor phase separation and classified their hydrothermal fluids into vapor-rich and brine-rich phases, respectively. The low pH values (pH = 5.67 ∼ 6.21) with downward increasing trends of pore-fluid dissolved inorganic carbon (DIC, up to 60 mmol L⁻¹) and its heavy isotopic compositions (<em>δ</em>¹³C_DIC = +2.5 ∼ +7.0 ‰) inferred <em>in-situ</em> liquid CO₂-impregnated sedimentary circumstance in the GLM and MHV hydrothermal fields. This sedimentary environment, as demonstrated, enhanced the chemical weathering of silicate and carbonate minerals, resulting in the elevated concentrations of Ca²⁺ and K⁺ in pore fluids. It highlights the impact of acidic and <em>in-situ</em> CO₂-saturated fluids within sediments on geochemical alterations of bulk solids/sediments and interstitial fluids.</p></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0967063724000633/pdfft?md5=cc2e51344f9b5cb4521ae5ecc3d66940&pid=1-s2.0-S0967063724000633-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140341291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of biopolymer concentration on the kinetics of marine snow formation","authors":"T.R. Akshaya ,&nbsp;Swathi Sudhakar ,&nbsp;Ethayaraja Mani ,&nbsp;Murali K.","doi":"10.1016/j.dsr.2024.104291","DOIUrl":"10.1016/j.dsr.2024.104291","url":null,"abstract":"<div><p>Marine snow floc refers to coagulation of microbes and marine debris in the upper ocean layers, bound together by bio-polymers such as transparent exopolymer particles (TEP) secreted by microbes. The stickiness of TEP plays a crucial role in determining the rate of marine snow floc formation. Additionally, the effect of TEP on the size distribution of marine snow influences the sinking velocity of the flocs. Using a surrogate material system, we study the kinetics of marine snow using a custom-built experimental setup, which allows direct measurement of floc size, floc number density, and floc sinking velocity as a function of TEP concentration. By comparing the experimental floc size with Smoluchowski coagulation theory, we obtain stickiness index, which increases with TEP concentration first, reaches maximum around 0.3 g/L of TEP and decreases upon further increase in TEP concentration. The experimental sinking velocity scales with floc size as <span><math><mrow><msub><mrow><mi>w</mi></mrow><mrow><mi>s</mi></mrow></msub><mo>=</mo><mi>a</mi><msup><mrow><mi>d</mi></mrow><mrow><mi>b</mi></mrow></msup></mrow></math></span>, with <span><math><mi>b</mi></math></span> ranging from 0.57 to 0.68. The exponent is slightly higher than that of 0.5 expected in the Stokes limit. This study establishes a clear link between stickiness index, sinking velocity, and polymer concentration, providing valuable insights for modelling of marine snow dynamics in deep ocean conditions. These findings contribute to a better understanding of the kinetics of marine snow formation, essential for predicting carbon sequestration within the biological carbon pump.</p></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140406477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Paleomagnetic secular variation and revised chronostratigraphy of Bering Sea (IODP expedition 323) deep-sea sediments (MIS 5)","authors":"Steve Lund ,&nbsp;Makoto Okada ,&nbsp;Emily Mortazavi","doi":"10.1016/j.dsr.2024.104265","DOIUrl":"10.1016/j.dsr.2024.104265","url":null,"abstract":"<div><p>This study presents new high-resolution, full-vector paleomagnetic secular variation (PSV) records from IODP Expedition 323 Sites U1339, U1343, U1344, and U1345 in the Bering Sea (51°N-60°N) during Marine Isotope Stage 5 (71–130 ka). The chronology of the records has been determined by oxygen isotope stratigraphy with an age uncertainty of ∼±2000 years. The data come from shipboard paleomagnetic measurements of deep-sea sediments with accumulation rates of 26–54 cm/ky. The sample interval in the composite records is 5 cm with a time resolution of ±100–200 years. The composite PSV records for each site were developed by correlation and analysis of 3–4 paleomagnetic records from individual holes at each site. The composite records are a combination of the best correlatable PSV data from each site. We have been able to significantly correlate the PSV records from all four sites. We have identified 56 inclination features (highs/lows) and 54 declination features (east/west extremes) in all the records. Relative paleointensity has been determined by normalizing the sediment natural remanence, after 20-mT af demagnetization, to magnetic susceptibility. This normalization process is complicated by environmental variability, thus our relative paleointensity records are limited to large-scale correlations among the four sites. We correlated our relative paleointensity records to the global PISO-1500 paleointensity record that is itself dated by oxygen isotope stratigraphy. We can identify 6 key intensity highs/lows in our composite records and the PISO-1500 record that provide additional dating isochrons for our records. There are three short magnetic field excursions recorded with replication at these four sites – The youngest excursion occurred at 100 ± 2 ka and is associated with the Fram Strait Excursion. Two older excursions occurred at 116 ± 2 ka and 119.5 ± 2 ka. We associate both of these with the Blake Event. All three of the excursions have very short time intervals (∼200–400 yrs) with somewhat out-of-phase inclination and declination variability. All three of these are Class I excursions. We have studied the statistical characteristics our composite records by calculating the 3ky and 9ky averaged inclinations, declinations, unit vectors, and relative paleointensity over 71–130 ka after removing all excursional directions. The averaged inclinations and declinations are consistent among the four sites. The averaged angular dispersion is bimodal in its overall pattern. Most of the time angular dispersion is low (∼±10°–12°) except for three shorter intervals that have significantly higher angular dispersion (∼±24–30°) and lower paleointensities. The high angular dispersion intervals are associated with the three short excursional intervals. The timing and pattern of interrelated high angular dispersion, low paleointensity, and excursions is synchronous with the PSV pattern recorded during MIS 5 in the central North Atlantic Ocean. We think ","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140404931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial variability of water mass transports in the Bransfield Strait based on direct current measurements","authors":"A.S. Gordey ,&nbsp;D.I. Frey ,&nbsp;I.D. Drozd ,&nbsp;V.A. Krechik ,&nbsp;D.A. Smirnova ,&nbsp;S.V. Gladyshev ,&nbsp;E.G. Morozov","doi":"10.1016/j.dsr.2024.104284","DOIUrl":"10.1016/j.dsr.2024.104284","url":null,"abstract":"<div><p>The Bransfield Strait connects the Bellingshausen and Weddell seas and is strongly affected by intense inflows of their water masses. In this work we analyzed Shipborne Acoustic Current Doppler Profiler (SADCP) measurements carried out in the Bransfield Strait from 2015 to 2022. The new dataset includes over 100 transects, crossing the main currents in the strait (namely, the Bransfield Current and the Transitional Weddell Water (TWW) flow). Based on these data, we studied spatial variability of water mass transports in the Bransfield Strait during austral summer season. As shown below in this research, the Bransfield Current was observed down to the 600 m depth. By considering deeper layers, we managed obtaining more precise assessments of mean water mass transports of the Bransfield Current. They were estimated at 1.4–2.1 Sv. We found that the transports of the Bransfield Current and TWW flow in the austral summer season (November–March) do not show significant variability. The water mass transport of the Bransfield Current and the TWW flow was stable within the central basin of the Bransfield Strait and differed in its western basin. We also found that in austral summer the heat transport into the Bransfield Strait varied between 0.2 and 0.4 Sv·°C and salinity transport was −0.07 to −0.06 Sv·psu, their sign reflecting a dominant northeastward flow of relatively warm and fresh water. In addition, we compared Lowered Acoustic Current Doppler Profiler (LADCP) and SADCP measurements and proved that the technical limitations of the SADCP do not significantly affect the estimates of the transports in this region.</p></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140268097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Depth and predation regulate consumption of dolphin carcasses in the hadal zone","authors":"Shamik Dasgupta ,&nbsp;Mingli Lin ,&nbsp;Shuangquan Liu,&nbsp;Shun Chen,&nbsp;Hengchao Xu,&nbsp;Jiwei Li,&nbsp;Kaiwen Ta,&nbsp;Songhai Li,&nbsp;Xiaotong Peng","doi":"10.1016/j.dsr.2024.104282","DOIUrl":"10.1016/j.dsr.2024.104282","url":null,"abstract":"<div><p>Natural whale falls and falls of smaller-sized food have been reported for more than 30 years and are known to be important sources of nutrients and organic matter for the seafloor community. However, the associated species composition and ecological processes during such events in the hadal zone were unknown. Therefore, we aimed to determine the impact of depth and predation on the hadal community during the early stages of a food-fall event. This is the first study to investigate the preliminary stages of the two deepest artificial dolphin-fall events in the Philippine Basin (PB) (∼7729 m) and Mariana Trench (MT) (∼8200 m). A total of nine dives were conducted over a period of 86 days (PB) and 50 days (MT) using the deep-sea manned submersible “Fendouzhe.” Our observations in the PB indicated that the first stage (mobile-scavenger) was controlled by the feeding ecology of hadal amphipods and snailfish. In contrast, the absence of predatory snailfish in the MT enhanced the degradation rate of the carcass compared to that in the PB. Most soft tissues were entirely consumed by scavenging amphipods within days of the event in the MT, whereas in the PB, amphipods were observed taking a feeding hiatus on Day 10 to escape snailfish predation. The second stage (enrichment-opportunist), which hosted few grazing faunas, began at different times in each location and overlapped with the mobile-scavenger stage. Dolphin carcasses, being smaller than those of full-grown whales, can only sustain a large community of scavenging amphipods, and indirectly, predatory snailfish. After the first stage, the dispersed organic matter and limited lipid content in dolphin bones were likely insufficient to sustain an active grazing community or the chemosynthetic community that typically follows. We concluded that water depth influences the successional stages and decomposition rate of food falls in the hadal zone by controlling the dynamic relationship between prey and predators. Our study elucidates the ecology of food-fall events in the hadal zone and highlights the key differences in food-fall events at different depths.</p></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140268053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two-decade satellite observations reveal variability in size-fractionated phytoplankton primary production in the South China Sea","authors":"Lin Deng ,&nbsp;Jun Zhao ,&nbsp;Shaojie Sun ,&nbsp;Bin Ai ,&nbsp;Wen Zhou ,&nbsp;Wenxi Cao","doi":"10.1016/j.dsr.2024.104258","DOIUrl":"https://doi.org/10.1016/j.dsr.2024.104258","url":null,"abstract":"<div><p>Understanding variations in marine phytoplankton primary production (PP) is crucial for assessing the response of the marine environment to climate change and for quantifying the ocean carbon cycle. However, the spatiotemporal variability of size-fractionated PP in the South China Sea (SCS) remains ambiguous. Our study investigated the monthly, seasonal, and inter-annual variability of size-fractionated PP in the SCS using satellite observations from 2002 to 2022. There were noticeable seasonal and monthly variations in size-fractionated PP, with notably high PP values appearing during the cold season. The disparities in distribution and the distinct fluctuation patterns between size-fractionated PP suggest that total PP alone is not a comprehensive indicator of marine ecosystem health. Over the past two decades in the SCS, there were more pronounced decreases in total, pico-, and nano-PP, whereas micro-PP displayed no significant trend. The most pronounced decline occurred in the northern SCS, contrasted by increases in coastal areas. These size-fractionated PP anomalies showed strong correlations with climate change indices, highlighting the impact of environmental factors on these anomalies, such as sea surface temperature, mixed layer depth, and wind speed. Our findings emphasize the importance considering size-fractionated PP to gain a more nuanced understanding of the ocean carbon cycle and the marine ecosystem's response to climate changes.</p></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140180344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trophic niche overlap of deep-sea fish species revealed by the combined approach of stomach contents and stable isotopes analysis in the Central Tyrrhenian Sea","authors":"Davide Cicala ,&nbsp;Alice Sbrana ,&nbsp;Tommaso Valente ,&nbsp;Daniela Berto ,&nbsp;Federico Rampazzo ,&nbsp;Maria Flavia Gravina ,&nbsp;Giulia Maiello ,&nbsp;Tommaso Russo","doi":"10.1016/j.dsr.2024.104281","DOIUrl":"https://doi.org/10.1016/j.dsr.2024.104281","url":null,"abstract":"<div><p>Understanding the trophic ecology of marine ecosystems is a key challenge given that they are subject to anthropogenic pressures that can alter the integrity of the food web. The bathyal zone of the Central Tyrrhenian Sea is characterized by an high level of community biodiversity, heavy anthropogenic pressure and thus represents a fundamental environment for the study of trophic relationships between demersal fish species which live in sympatry, but this basin still remains data deficient. To fill this information gap, we investigated the trophic niche overlap of four deep-sea fish species, <em>Galeus melastomus</em>, <em>Helicolenus dactylopterus</em>, <em>Lepidorhombus boscii</em>, and <em>Trisopterus capelanus</em>, in the Central Tyrrhenian Sea using an integrated approach of stomach content and stable isotopes analysis (δ¹³C and δ¹⁵N). Our analysis revealed that the blackmouth catshark <em>G. melastomus</em> displays a wide trophic niche with considerable overlap with other fish species, as it consumed diverse prey including fish, crustaceans, and cephalopods, thus proving a generalist and opportunistic feeding behavior. The blackbelly rosefish <em>H. dactylopterus</em> exhibits a narrower isotopic trophic niche comprising mainly benthic crustaceans and so suggesting a marked specialism in feeding strategy. The diet of the four-spotted megrim <em>L. boscii</em> showed a marked overlap with that <em>H. dactylopterus,</em> as these species shared a similar benthic habit and relied upon a similar pool of resource. The poor cod <em>T. capelanus</em> showed a diverse diet comprising both prey captured close to the bottom, especially decapod and mysid crustaceans, and bathypelagic prey, mainly Osteichthyes, Myctophidae, and amphipod Hyperiidae, with an intermediate partially segregated isotopic niche width. The combination of stomach content analysis and stable isotopes analysis provided the first characterization of the trophic relationships, shedding light on the trophic niche overlap of these four ecologically important deep sea fish species. The diets of the four investigated species showed similarities in the composition of prey, but also differences which allows them to partially reduce competition. This information may be of crucial relevance for the development of effective management and conservation strategies for the bathyal Mediterranean environment.</p></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140163488","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transformation of the atlantic water between svalbard and Franz Joseph Land in the late winter 2018–2019","authors":"V.V. Ivanov ,&nbsp;A.V. Danshina ,&nbsp;A.V. Smirnov ,&nbsp;K.V. Filchuk","doi":"10.1016/j.dsr.2024.104280","DOIUrl":"https://doi.org/10.1016/j.dsr.2024.104280","url":null,"abstract":"<div><p>An inflow of warm and salty Atlantic origin waters (AW) from the Nordic Seas to the Arctic Ocean interior is in the list of the major external factors, which control the hydrologic regime of the East-Atlantic sector of the Arctic Ocean. Rapid decay of the sea ice cover in 2000–2010s raised questions on the possible changes in the fate of the inflow under present ice-depleted conditions: whether warm and salty AW will cool and freshen slower (due to less ice to be melted underway), or intensified heat loss to the atmosphere through the open surface will lead to the faster AW cooling on shorter distance? We present rare hydrologic data, collected during the late winter 2019 in the international expedition “Transarktika-2019” in the northern part of the Barents Sea and at the adjoining continental slope of the Nansen Basin. On the basis of field data, supported by the oceanic reanalysis product and numerical modelling we have studied the transformation of AW on its transit between Svalbard and Franz Joseph Land. We show that the observed cooling and desalination of the fraction of AW over the continental slope around this area is controlled by lateral mixing with colder and fresher waters, outflowing from cross-slope canyons, which cut the continental slope: Kvitøya Trough, Franz Victoria Trough and probably, the British Channel. The obtained results demonstrate more intensive transformation of AW on this transit compared to previous studies. Possible explanations of this contrast, which are supported by the earlier studies, may include: the season of the survey when dense water outflow through canyons is at its maximum and gradual “atlantification” of the East-Atlantic sector of the Arctic Ocean, which favours intensification of dense water formation in winter polynyas under conditions of increased seasonality of sea ice. In the latter case, faster cooling and desalination of AW en route in this part of the Arctic Ocean may be considered as a reasonable hypothesis, provided the atlantification of the Nansen Basin is progressing.</p></div>","PeriodicalId":51009,"journal":{"name":"Deep-Sea Research Part I-Oceanographic Research Papers","volume":null,"pages":null},"PeriodicalIF":2.4,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140141595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}