Academic literature on the topic 'Marine plankton – Vertical distribution'
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Journal articles on the topic "Marine plankton – Vertical distribution"
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TIMM, U. "VERTICAL PHYTOPLANKTON DISTRIBUTIONS: PATTERNS AND ANALYTICAL SOLUTIONS." Journal of Biological Systems 02, no. 02 (June 1994): 137–63. http://dx.doi.org/10.1142/s021833909400012x.
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I apply the basic equations of fluid dynamics to reaction—diffusion—advection models describing vertical distribution patterns of marine plankton. The biological dynamics in these models are growth, death/birth, grazing and interaction. Further, oceanographic phenomena such as shading and shear dispersion are considered. Models for critical patch size and for vertical distribution profiles and analytical solutions are developed.
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Tang, S., A. G. Lewis, M. Sackville, L. Nendick, C. DiBacco, C. J. Brauner, and A. P. Farrell. "Diel vertical distribution of early marine phase juvenile pink salmon (Oncorhynchus gorbuscha) and behaviour when exposed to salmon louse (Lepeophtheirus salmonis)." Canadian Journal of Zoology 89, no. 9 (September 2011): 796–807. http://dx.doi.org/10.1139/z11-049.
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We observed diel vertical migration patterns in juvenile pink salmon ( Oncorhynchus gorbuscha (Walbaum, 1792)) and tested the hypothesis that fish behaviour is altered by exposure to sea lice copepodids. Experiments involved replicated field deployments of a large (9 m) plankton column, which provided a vertical distribution enclosure under natural light and salinity conditions. Diel vertical distributions of juvenile pink salmon were observed during the first 3 weeks of seawater acclimation in both the presence and the absence of the ectoparasitic salmon louse ( Lepeophtheirus salmonis (Krøyer, 1838)). Immediately upon entering seawater, juvenile pink salmon preferred the top 1 m of the water column, but they moved significantly deeper down the vertical water column as seawater acclimation time increased. A significant diel migration pattern was observed, which involved a preference for the surface at night-time, compared with daytime. When fish in the column were exposed to L. salmonis copepodids for 3 h, 43%–62% of fish became infected, fish expanded their vertical distribution range, and significant changes in vertical distribution patterns were observed.
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AZZALI, IRENE, ANDREW MOROZOV, and EZIO VENTURINO. "EXPLORING THE ROLE OF VERTICAL HETEROGENEITY IN THE STABILIZATION OF PLANKTONIC ECOSYSTEMS UNDER EUTROPHICATION." Journal of Biological Systems 25, no. 04 (December 2017): 715–41. http://dx.doi.org/10.1142/s0218339017400034.
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Understanding plankton dynamics in marine and lake ecosystems under eutrophication is currently a hot topic in the literature. Simple theoretical models predict appearance of large amplitude oscillations of species densities in nutrient-rich waters; however, such predictions do not always correspond to field observations. Recent models taking into account heterogeneity of the growth rate of phytoplankton and active food-searching behavior of zooplankton demonstrated that grazers can efficiently control phytoplankton densities at low values even for a high nutrient stock. In this paper, we extend the previous modeling findings on the role of fast-moving plankton grazers by exploring a more realistic case where the limiting nutrient is a dynamical variable. Thus, the growth of phytoplankton across the water column depends on both light attenuation and dynamical depletion of nutrients. We also consider a more realistic scenario of a depth-dependent vertical turbulent diffusion. Most of the previous results on stabilization of planktonic ecosystems still hold; however, some alternative mechanisms of bloom suppression can also be possible. In particular, we demonstrate that the foraging of zooplankton according to the ideal free distribution (IFD) of food (which was previously considered to be a crucial condition for stabilization) may be less stabilizing than random foraging of zooplankton. We also show that stable top-down control in the ecosystem would be highly dependent on values of vertical diffusion and on the nutrient concentration in deep layers.
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Davis, Catherine V., Karen Wishner, Willem Renema, and Pincelli M. Hull. "Vertical distribution of planktic foraminifera through an oxygen minimum zone: how assemblages and test morphology reflect oxygen concentrations." Biogeosciences 18, no. 3 (February 10, 2021): 977–92. http://dx.doi.org/10.5194/bg-18-977-2021.
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Abstract. Oxygen-depleted regions of the global ocean are rapidly expanding, with important implications for global biogeochemical cycles. However, our ability to make projections about the future of oxygen in the ocean is limited by a lack of empirical data with which to test and constrain the behavior of global climatic and oceanographic models. We use depth-stratified plankton tows to demonstrate that some species of planktic foraminifera are adapted to life in the heart of the pelagic oxygen minimum zone (OMZ). In particular, we identify two species, Globorotaloides hexagonus and Hastigerina parapelagica, living within the eastern tropical North Pacific OMZ. The tests of the former are preserved in marine sediments and could be used to trace the extent and intensity of low-oxygen pelagic habitats in the fossil record. Additional morphometric analyses of G. hexagonus show that tests found in the lowest oxygen environments are larger, more porous, less dense, and have more chambers in the final whorl. The association of this species with the OMZ and the apparent plasticity of its test in response to ambient oxygenation invites the use of G. hexagonus tests in sediment cores as potential proxies for both the presence and intensity of overlying OMZs.
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Hoshiba, Yasuhiro, Takafumi Hirata, Masahito Shigemitsu, Hideyuki Nakano, Taketo Hashioka, Yoshio Masuda, and Yasuhiro Yamanaka. "Biological data assimilation for parameter estimation of a phytoplankton functional type model for the western North Pacific." Ocean Science 14, no. 3 (June 1, 2018): 371–86. http://dx.doi.org/10.5194/os-14-371-2018.
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Abstract. Ecosystem models are used to understand ecosystem dynamics and ocean biogeochemical cycles and require optimum physiological parameters to best represent biological behaviours. These physiological parameters are often tuned up empirically, while ecosystem models have evolved to increase the number of physiological parameters. We developed a three-dimensional (3-D) lower-trophic-level marine ecosystem model known as the Nitrogen, Silicon and Iron regulated Marine Ecosystem Model (NSI-MEM) and employed biological data assimilation using a micro-genetic algorithm to estimate 23 physiological parameters for two phytoplankton functional types in the western North Pacific. The estimation of the parameters was based on a one-dimensional simulation that referenced satellite data for constraining the physiological parameters. The 3-D NSI-MEM optimized by the data assimilation improved the timing of a modelled plankton bloom in the subarctic and subtropical regions compared to the model without data assimilation. Furthermore, the model was able to improve not only surface concentrations of phytoplankton but also their subsurface maximum concentrations. Our results showed that surface data assimilation of physiological parameters from two contrasting observatory stations benefits the representation of vertical plankton distribution in the western North Pacific.
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Peterson, Jay O., and William T. Peterson. "Influence of the Columbia River plume (USA) on the vertical and horizontal distribution of mesozooplankton over the Washington and Oregon shelf." ICES Journal of Marine Science 65, no. 3 (January 31, 2008): 477–83. http://dx.doi.org/10.1093/icesjms/fsn006.
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Abstract Peterson, J. O., and Peterson, W. T. 2008. Influence of the Columbia River plume (USA) on the vertical and horizontal distribution of mesozooplankton over the Washington and Oregon shelf. – ICES Journal of Marine Science, 65: 477–483. River plumes extending out over continental shelf waters have distinct frontal boundaries along their leading edges that concentrate highly buoyant particles, including zooplankton. The margin between the base of the plume and the underlying oceanic waters is often many times larger in spatial extent than the visible surface front, but the influence of this region of a river plume on the vertical and horizontal distribution of zooplankton is less well understood. Using a laser optical plankton counter (LOPC) and a conductivity–temperature–depth sensor (CTD) mounted to a rapidly undulating tow body, we examined the horizontal and vertical distribution of zooplankton proximate to the Columbia River plume, to study how plume waters affect zooplankton over the continental shelf. Overall, vertically integrated zooplankton abundance and biovolume was elevated close to “aged” plume waters. Zooplankton tended to aggregate near the surface close to river plume waters. When plume waters are present at the surface, zooplankton aggregations tended to be in the upper 10 m of the water column, compared with 25 m when the plume was not present. The presence of river plumes may be ecologically and energetically important to surface feeding planktivores such as larval and juvenile fish.
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Pérez-Santos, Iván, Leonardo Castro, Lauren Ross, Edwin Niklitschek, Nicolás Mayorga, Luis Cubillos, Mariano Gutierrez, et al. "Turbulence and hypoxia contribute to dense biological scattering layers in a Patagonian fjord system." Ocean Science 14, no. 5 (October 9, 2018): 1185–206. http://dx.doi.org/10.5194/os-14-1185-2018.
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Abstract. The aggregation of plankton species along fjords can be linked to physical properties and processes such as stratification, turbulence and oxygen concentration. The goal of this study is to determine how water column properties and turbulent mixing affect the horizontal and vertical distributions of macrozooplankton along the only northern Patagonian fjord known to date, where hypoxic conditions occur in the water column. Acoustic Doppler current profiler moorings, scientific echo-sounder transects and in situ plankton abundance measurements were used to study macrozooplankton assemblages and migration patterns along Puyuhuapi Fjord and Jacaf Channel in Chilean Patagonia. The dissipation of turbulent kinetic energy was quantified through vertical microstructure profiles collected throughout time in areas with high macrozooplankton concentrations. The acoustic records and in situ macrozooplankton data revealed diel vertical migrations (DVM) of siphonophores, chaetognaths and euphausiids. In particular, a dense biological backscattering layer was observed along Puyuhuapi Fjord between the surface and the top of the hypoxic boundary layer (∼100 m), which limited the vertical distribution of most macrozooplankton and their DVM, generating a significant reduction of habitat. Aggregations of macrozooplankton and fishes were most abundant around a submarine sill in Jacaf Channel. In this location macrozooplankton were distributed throughout the water column (0 to ∼200 m), with no evidence of a hypoxic boundary due to the intense mixing near the sill. In particular, turbulence measurements taken near the sill indicated high dissipation rates of turbulent kinetic energy (ε∼10-5 W kg−1) and vertical diapycnal eddy diffusivity (Kρ∼10-3 m2 s−1). The elevated vertical mixing ensures that the water column is well oxygenated (3–6 mL L−1, 60 %–80 % saturation), creating a suitable environment for macrozooplankton and fish aggregations. Turbulence induced by tidal flow over the sill apparently enhances the interchange of nutrients and oxygen concentrations with the surface layer, creating a productive environment for many marine species, where the prey–predator relationship might be favored.
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Lira, Simone Maria de Albuquerque, Igor de Ávila Teixeira, Cynthia Dayanne Mello de Lima, Gleice de Souza Santos, Sigrid Neumann Leitão, and Ralf Schwamborn. "Spatial and nycthemeral distribution of the zooneuston off Fernando de Noronha, Brazil." Brazilian Journal of Oceanography 62, no. 1 (March 2014): 35–45. http://dx.doi.org/10.1590/s1679-87592014058206201.
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Island environments drastically modify the hydrodynamics of ocean currents and generate strong vertical turbulence. This leads to an upward transport of nutrient-rich waters, thus increasing the biomass of plankton in these oceanic marine environments. The objective of this study was to assess the biomass and density of the zooneuston communities in relation to the upper and lower layers (epi-/hyponeuston), the nycthemeral variation (day/night), the currents in relation to the island (downstream vs upstream), and the distance from the island, focusing on the spatial variability. Samples were taken in July and August 2010 with a David-Hempel neuston net (Hydro-Bios) with a mesh size of 500 µm. Twenty-one taxa were recorded. The most abundant taxa were Copepoda, Chaetognatha, Teleostei (eggs) and Hydrozoa. This is the first record of phoronid larvae for the waters of the Tropical Atlantic. For both layers, density and biomass were significantly higher at night. Density and biomass were always significantly higher in the upper (epineuston) layer than in the lower (hyponeuston) layer. This was probably due to a zooneuston aggregation at the surface and massive vertical migration from deep waters at night, leading to increased abundances at night in both neuston layers.
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Lebourges-Dhaussy, Anne, Janet Coetzee, Larry Hutchings, Gildas Roudaut, and Cornelia Nieuwenhuys. "Zooplankton spatial distribution along the South African coast studied by multifrequency acoustics, and its relationships with environmental parameters and anchovy distribution." ICES Journal of Marine Science 66, no. 6 (May 8, 2009): 1055–62. http://dx.doi.org/10.1093/icesjms/fsp129.
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Abstract Lebourges-Dhaussy, A., Coetzee, J., Hutchings, L., Roudaut, G., and Nieuwenhuys, C. 2009. Zooplankton spatial distribution along the South African coast studied by multifrequency acoustics, and its relationships with environmental parameters and anchovy distribution. – ICES Journal of Marine Science, 66: 1055–1062. The Central Agulhas Bank (CAB) is an important component of the southern Benguela ecosystem. Despite relatively low primary production, secondary production supports large populations of mid-trophic-level pelagic fish. Exhaustive sampling of the Agulhas Bank ecosystem was performed during a routine acoustic biomass survey in November 2006. A TAPS-6 was deployed with near-simultaneous, plankton-net sampling. Concurrent collections of fish-school and environmental data permitted a detailed study of the water column. Zooplankton was classified by equivalent spherical diameter (ESD; mm): 0.0–0.35 (Class I), 0.35–0.8 (Class II), 0.8–2 (Class III), and >2.0 mm (Class IV). Clear relationships with environmental parameters were only evident at night on the CAB (west of 23°E) for Classes II and III. Class III exhibited pronounced diel vertical migrations, whereas Class I exhibited a reverse pattern. Also observed were the effects of anchovy predation on small zooplankton aggregated in areas of high chlorophyll a.
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Bollens, Stephen M., and Bruce W. Frost. "UV light and vertical distribution of the marine planktonic copepod Acartia hudsonica Pinhey." Journal of Experimental Marine Biology and Ecology 137, no. 2 (May 1990): 89–93. http://dx.doi.org/10.1016/0022-0981(90)90062-h.
Full textDissertations / Theses on the topic "Marine plankton – Vertical distribution"
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Arenovski, Andrea Lynn. "The distribution, abundance and ecology of mixotrophic algae in marine and freshwater plankton communities." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/33523.
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Ballón, Soto Roberto Michael. "Étude acoustique du macrozooplancton au Pérou : estimation de biomasse, distribution spatiale, impact du forçage physique, et conséquences sur la distribution des poissons fourrage." Thesis, Montpellier 2, 2010. http://www.theses.fr/2010MON20052/document.
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La partie nord du Système du courant de Humboldt (NSCH) couvre moins de 0.1% de la surface océanique mondiale mais produit plus de poisons, en particulier d'anchois du Pérou (Engraulis ringens), par unité de surface que n'importe quelle autre région du monde. Bien que ce système produise suffisamment de macrozooplancton pour alimenter les populations de poisson fourrage, le manque d'informations sur ce compartiment limite nos capacités d'étude. L'objectif de cette thèse est d'étudier la dynamique de la distribution spatiotemporelle de la biomasse en macrozooplancton du NSCH en relation avec l'environnement physique et les poissons fourrage, à différentes échelles. Pour ce faire une méthode acoustique bi-fréquences a été développée et appliqué à des séries de données acoustiques historiques. Des informations à haute résolution ont ainsi pu être extraite sur la biomasse et les patrons de distribution du macrozooplancton, de la galathée pélagique 'munida', des poissons et des autres compartiments. Cette méthode nous a également permis d'estimer l'extension verticale de la communauté épipélagique (ZVEEC). Nous avons démontré que ZVEEC coïncide avec la limite supérieure de la zone de minimum d'oxygène (ZMO), ce qui permet de produire des donnés spatialisées à haute résolution de la limite supérieure de la ZMO et d'estimer le volume d'habitat de l'anchois. Notre estimation de biomasse en macrozooplancton, environ quatre fois supérieures aux estimations antérieures, est en accord avec les découvertes récentes sur l'écologie trophique des poissons fourrage du NSCH et fournit des éléments étayant les théories actuelles sur l'origine de la haute productivité en poissons du NSCH. L'étude des impacts des structures physiques de submeso- et mesoéchelle sur la distribution du macrozooplancton supporte l'hypothèse d'une structuration de type 'bottom-up'. Nous avons également mis en évidence l'impact de la structuration spatiale du macrozooplancton sur la distribution des poissons fourrage. Les données physiques et biologiques à haute résolution obtenues grâce à cette étude ouvrent de nouvelles perspectives pour réaliser des études écologiques intégrées à échelles multiples et pour calibrer les modèles biogéochimiques, trophiques ou End-to-EndThe Northern Humboldt Current system (NHCS) represents less than 0.1% of the world ocean surface but produces more fish, mainly Peruvian anchovy (Engraulis ringens), per unit area than any other region in the world. Although this system produces enough macrozooplankton to feed its high production of forage fish, the paucity of information on zooplankton hampers research in the system. The objective of this study was to investigate the multiscale dynamics of the spatiotemporal distribution of the macrozooplankton biomass off Peru in relation to the physical environment and their fish predators. For that a bi-frequency acoustic method was developed and applied to extract, from historical acoustic data, high-resolution information on the biomass and the patterns of distribution of macrozooplankton, the pelagic red squad 'munida', fish and other marine compartments. This method also allows estimating the vertical extension of this epipelagic community (ZVEEC). We demonstrated that ZVEEC coincide with the upper limit of the oxygen minimum zone (OMZ), which allowed both producing high-resolution spatial data of the upper limit of the OMZ and estimating the volume habitat of anchovy. The estimated macrozooplankton biomass was about four times higher than previously reported. This estimate is in agreement with the recent findings on forage fish trophic ecology and supports the current hypotheses explaining the NHCS high fish production. The study of the impacts of the submeso- and mesoscale physical structures on macrozooplankton provided evidence of the bottom-up physical effect on the distribution of macrozooplankton biomass. We also found further evidence of the structuring bottom-up effect that macrozooplankton exert on forage fish. The high-resolution biological and physical data obtained in this study opens new perspective to perform integrated multiscale ecological studies and to calibrate biogeochemical, trophic and End-to-End models
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Fine, Charles Douglas. "The Vertical and Horizontal Distribution of Deep-Sea Crustaceans of the Order Euphausiacea (Malacostraca: Eucarida) from the northern Gulf of Mexico with notes on reproductive seasonality." NSUWorks, 2016. http://nsuworks.nova.edu/occ_stuetd/432.
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The vertical and horizontal distributions of Euphausiacea in the northern Gulf of Mexico, including the location of the Deepwater Horizon oil spill, were analyzed from 340 trawl samples collected between April-June, 2011. This study is the first comprehensive survey of euphausiid distributions from depths deeper than 1000 m in the Gulf of Mexico and included stratified sampling from five discrete depth ranges (0-200 m, 200-600 m, 600-1000 m, 1000-1200 m, and 1200-1500 m). In addition, this study encompasses the region heavily impacted by the Deepwater Horizon oil spill. Data presented here could potentially be used in ecosystem models investigating trophic effects of the spill because euphausiids are the preferred prey of a variety of higher trophic organisms. Lastly, these data represent the first quantification of euphausiid assemblages in this location after the Deepwater Horizon event and can serve as a basis of comparison against which to monitor recovery of the euphausiid assemblage after exposure to Deepwater Horizon hydrocarbons and dispersant in the water column.
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Romagnan, Jean-Baptiste. "Les communautés planctoniques des bactéries au macroplancton : dynamique temporelle en Mer Ligure et distribution dans l'océan global lors de l'expédition Tara Oceans. - Approche holistique par imagerie -." Thesis, Nice, 2013. http://www.theses.fr/2013NICE4050.
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Le plancton constitue l’essentiel de la biomasse pélagique et est un acteur majeur des cycles biogéochimiques globaux qui régulent le système Terre. Il comprend l'ensemble des organismes portés par les courants, des bactéries aux méduses géantes. La communauté n'est que très rarement étudiée dans son ensemble mais plutôt par fraction. L’expédition Tara Oceans constitue le premier effort de collecte simultané de toutes les classes de taille de plancton à l’échelle de l’océan global. Pour démontrer la faisabilité de cette approche à grande échelle, des échantillons hebdomadaires de plancton, depuis les bactéries jusqu’au macroplancton gélatineux, ont d’abord été analysés en combinant plusieurs instruments d’imagerie sur une période de 10 mois, en un site de référence (point B) dans la rade de Villefranche sur mer. L’imagerie nous a permis de comparer 1) l’information fonctionnelle définie comme l’agrégation de taxons en 18 Groupes Ecologiques de Plancton (GEP), et 2) la structure en taille des communautés échantillonnées sur un intervalle de taille de 6 ordres de grandeur (0.1 µm à 10000 µm). La communauté planctonique au point B évolue en une succession écologique complexe impliquant tous les groupes planctoniques, depuis les bactéries jusqu’aux prédateurs gélatineux du macroplancton. Des évènements impulsifs, tels que des coups de vent, déclenchent des réorganisations de la communauté par un jeu d’interactions entre des contrôles « bottom-up » et « top-down ». Toutefois, le biovolume planctonique total ne varie que d’un seul ordre de grandeur au cours de la période échantillonnée. De même, la structure en taille des communautés planctoniques totales ne varie pas significativement au cours du temps. La stabilité du biovolume total et de la structure en taille suggère que des mécanismes structurant et de compensation forts maintiennent les communautés planctoniques dans un intervalle de biomasse restreint. Le couplage entre données de taille et de taxonomie révèle une réorganisation du réseau trophique entre l’été et l’hiver. En hiver, Le réseau trophique microplancton-zooplancton est dominé par la fonction de broutage. En été, le réseau trophique microplancton-zooplancton est dominé par la fonction de prédation (chaetognathes et gélatineux carnivores). En été, ce réseau trophique s’organise en deux chaines trophiques parallèles et distinctes discriminées par des relations de taille entre proies et prédateurs. Cette réorganisation souligne le rôle clef du zooplancton et de la prédation dans la structuration des communautés planctoniques. Parallèlement à cette analyse temporelle en un point fixe, nous avons montré l’existence de types caractéristiques de communautés zooplanctoniques, associés à des conditions environnementales distinctes, à partir des échantillons de l’expédition Tara Oceans, à l’échelle globale. En utilisant la même méthodologie que pour l’analyse de la dynamique temporelle, nous avons identifié trois types de communautés mésozooplanctoniques à l’échelle globale selon le type d’environement: 1) des communautés associées aux environnements productifs (upwellings côtiers et équatoriaux), 2) des communautés associées aux zones de minimum d’oxygène (OMZs, « Oxygen Minimum Zones »), et 3) des communautés associées aux gyres océaniques oligotrophes. Ce travail constitue une première typologie des communautés zooplanctoniques, structurées en taille et GEP, à l’échelle globale. Il sera complété dans le futur par l’intégration de données issus des autres compartiments planctoniques, et de données d’export vertical de matière organique particulaire pour affiner les estimations des relations qui existent entre phytoplancton, zooplancton et flux biogéochimiquesPlankton constitutes the bulk of pelagic biomass and plays a major role in the global biogeochemical cycles that regulate the earth system. It encompasses all the organisms that drift with the water masses movements, from bacteria to giant medusae. Studies of the entire community are scarce, and plankton has been traditionally studied by fractions. The Tara Oceans expedition is the first attempt to simultaneously collect plankton in every size classes at the global scale. To demonstrate the feasibility of this approach, samples of plankton from bacteria to gelatinous macroplankton were collected weekly over ten months at a reference site (point B), in Villefranche Bay, northwestern Mediterranean, and analyzed using imaging techniques. Imaging enabled us to compare 1) the functional taxonomic information as derived from the analysis of 18 Plankton Ecological Groups (PEGs), and 2) the size structure of the same planktonic community over 6 orders of magnitude in size. The plankton dynamics at point B are driven by a complex succession process involving all plankton groups, from bacteria to macroplanktonic gelatinous predators. Environmental impulsive events such as wind events trigger sharp community level reorganizations via interplay of bottom-up controls followed by top-down controls. However, the total biovolume of the planktonic community varies within only one order of magnitude over the period studied. In addition, the size structure of the entire community does not vary significantly over time. The total biovolume and size structure stability suggest that strong and compensative mechanisms drive community dynamics within a narrow range of biomass variation. The use of both taxonomic and size structured data reveals a reorganization of the food web between winter and summer. In winter and spring the microplanktoniczooplanktonic food web is shaped by the grazing function. In summer, it is shaped by the predation function (chaetognaths and gelatinous predators). In summer, the food web self organizes in two distinct food chains discriminated by size relations between predators and preys. This reorganization underlines the key role of zooplankton and predation in structuring planktonic communities. In parallel to this temporal dynamics study, we used the Tara Oceans expedition samples to study the global scale distribution of mesozooplankton. We showed that characteristic mesozooplanktonic communities were associated with distinct environmental conditions, at the global scale. Using a similar methodology as for the temporal study we found that three different mesozooplanktonic communities were associated with 1) productive environments (e.g. upwellings), 2) Oxygen Minimum Zones, and 3) Oligotrophic oceanic gyres. This work is the first typology of mesozooplanktonic communities at the global scale. It will be further developed in the future by the integration of other planktonic compartments and particulate organic matter fluxes data, to improve our knowledge on the relations between phytoplankton, zooplankton and particulate organic matter fluxes
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Reboul, Guillaume. "Metabarcoding and metagenomic approaches to decipher microbial communities in suboxic environments Microbial eukaryotes in the suboxic chemosyn- thetic ecosystem of Movile Cave, Romania Hyper- diverse archaea near life limits at the polyextreme geothermal Dallol area Performance of the melting seawater-ice elution method on the metabarcoding characterization of benthic protist communities Core microbial communities of lacustrine microbialites sampled along an alkalinity gradient Environmental drivers of plankton protist communities along latitudinal and vertical gradients in the oldest and deepest freshwater lake Ancient Adaptive Lateral Gene Transfers in the Symbiotic Opalina-Blastocystis Stramenopile Lineage Marine signature taxa and microbial community stability along latitudinal and vertical gradients in sediments of the deepest freshwater lake." Thesis, université Paris-Saclay, 2020. http://www.theses.fr/2020UPASL041.
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L’écologie microbienne concerne l’étude des microorganismes et de leurs interactions biotiques et abiotiques dans un écosystème donné. Ces vingt dernières années, l’avancement des techniques moléculaires pour analyser la diversité microbienne et, notamment, les nouvelles technologies de séquençages (NGS) ont permis de surmonter les limitations associées aux approches traditionnelles basées sur la culture et la microscopie. Ces approches moléculaires ont conduit à une accumulation des données de diversité microbienne et de potentiel métabolique dans des communautés microbiennes des écosystèmes variés.Cependant, ces efforts ont été principalement appliqués sur des environnements facilement accessibles ou liés à l’humain, comme le plancton (marin principalement) et la flore intestinale. Néanmoins, ceci a conduit à une très forte augmentation de données environnementales et au développement de la bioinformatique par le biais de nombreux outils. Parmi les environnements délaissés des études, les environnements faibles en oxygène sont probablement également porteurs de nouveautés phylogénique ou métaboliques.Afin de palier à cela, nous avons choisi d’explorer deux environnements suboxiques relativement peu étudiés : la cave Movile (Roumanie) et les sédiments du lac Baikal (Sibérie, Russie). Notre but étant de montrer les diversités phylogénétiques et fonctionnelles des microbes de ces biotopes.Pour cela, j’ai d'abord développé un pipeline d’analyse de données métabarcoding (petite sous-unités ribosomique). Ensuite, j’ai appliqué cet outil sur des données de métabarcoding de protistes provenant d’échantillons d’eau et de tapis microbiens de la cave de Movile, un écosystème chemosynthétique pratiquement fermé. Nous avons montré que la diversité des protistes de la cave s’étendait à quasiment tous les grands groupes eucaryotes et provenait à la fois d’origine d’eaux douces et marines. De plus, la plupart ont été affiliées à des groupes d’organismes typiquement anaérobies, ce qui est concordant avec les paramètres abiotiques de la cave. Écologiquement, ces protistes sont des prédateurs mais aussi vraisemblablement des partenaires symbiotiques avec des espèces procaryotes de la cave.Dans une deuxième étude, j’ai eu l’opportunité d’appliquer ce pipeline de métabarcoding sur des données procaryotes et eucaryotes provenant des couches superficielles des sédiments du lac d’eau douce Baikal. Comme attendu, les communautés microbiennes dans ces sédiments sont particulièrement diverses et relativement enrichis en archées. Nous avons aussi pu mettre en évidence des lignées que l’on pensait exclusivement marines dans ces sédiments. Ces lignées sont probablement planctoniques mais s’accumulent au fond par sédimentation. Enfin, les échantillons ont été prélevés dans le but de tester les influences de la profondeur, du bassin et de la latitude sur les communautés. Aucune d’elles ne s’est révélée significative.Dans une troisième étude, j'ai utilisé une approche métagénomique afin de révéler les acteurs écologiquement majeurs dans les sédiments, leurs rôles et de reconstruire leurs génomes. Cela nous a permis notamment de mettre en évidence le rôle primordial des Thaumarchaeota dans le cycle de l’azote et la production primaire de molécules de carbone. Les chloroflexi et les protéobacteries ont aussi un rôle important dans la surface des sédiments du lac Baikal. Ce travail de thèse participe à la connaissance globale de la diversité microbienne sur la planète en mettant en lumière des environnements peu étudiés. De plus, l’étude de la surface des sédiments du lac Baikal apporte de nouvelles données sur le sujet de la transition eau douces/eau marines des microbes. Enfin, la métagénomique a permis de révéler le cycle des nutriments et les microorganismes y participant dans ces échantillons de sédiment. En résumé, ce travail vient mettre en lumière l’écologie microbienne d’écosystèmes suboxiques, notamment la surface des sédiments du lac BaikalMicrobial ecology is the science of micro-organisms and their biotic and abiotic interactions in a given ecosystem. As technology has advanced, molecular techniques have been widely used to overcome the limitations of classical approaches such as culturing and microscopy. Indeed, the development of Next Generation Sequencing (NGS) technologies in the past twenty years has largely helped to unravel the phylogenetic diversity and functional potential of microbial communities across ecosystems.Nonetheless, most of the environments studied through these techniques concentrated on relatively easily accessible, tractable and host-related ecosystems such as plankton (especially in marine ecosystems), soils and gut microbiomes. This has contributed to the rapid accumulation of a wealth of environmental diversity and metagenomic data along with advances in bioinformatics leading to the development of myriads of tools. Oxygen-depleted environments and especially their microbial eukaryote components are less studied and may lead to future phylogenetic and metabolic discoveries.In order to address this, we conducted analyses on two poorly studied suboxic ecosystems: Movile Cave (Romania) and lake Baikal sediments (Siberia, Russia). In this task, we aimed at unveiling the taxonomic and functional diversity of microorganims in these environments.To do so, I first evaluated the available bioinformatics tools and implemented a bioinformatics pipeline for 16S/18S rRNA gene-based metabarcoding analysis, making reasoned methodological choices. Then, as a case study, I carried out metabarcoding analyses of the water and floating microbial mats found in Movile Cave in order to investigate its protist diversity. Our study showed that Movile Cave, a sealed off chemosynthetic ecosystem, harbored a substantial protist diversity with species spanning most of the major eukaryotic super groups. The majority if these protists were related to species of freshwater and marine origins. Most of them were putatively anaerobic, in line with the cave environment, and suggesting that in addition to their predatory role, they might participate in prokaryote-protist symbioses.In a second study, I applied my metabarcoding pipeline to explore unique and relatively unexplored environment of Lake Baikal sediments. I first applied a metabarcoding approach using 16S and 18S rRNA genes to describe prokaryotic as well as protist diversity. Overall, the communities within these ecosystems were very diverse and enriched in ammonia-oxidizing Thaumarchaeota. We also identified several typical marine taxa which are likely planktonic but accumulate in sediments. Finally, our sampling plan allowed us to test whether differences across depth, basin or latitude affected microbial community structure. Our results showed that the composition of sediment microbial communities remained relatively stable across the samples regardless of depth or latitude.In a third study, we applied metagenomics to study the metabolic potential of communities associated to Baikal sediments and to reconstruct metagenome-assembled genomes (MAGs) of dominant organisms. This revealed the considerable ecological importance of Thaumarchaeota lineages in lake Baikal sediments, which were found to be the major autotrophic phyla and also very implicated in the nitrogen cycle. Chloroflexi and Proteobacteria-related species also appeared ecologically important.This PhD thesis reveals the taxonomic diversity of poorly studied suboxic ecosystems and therefore contributes to our knowledge of microbial diversity on Earth. Additionally, the analyses of surface sediment samples in lake Baikal adds new light on freshwater-marine transitions. The metagenomic analyses reported here allowed us to postulate a model of nutrient cycle carried out by microorganismsin these sediments. Overall, this work sheds light on the microbial ecology of oxygen-depleted environments, and most notably lake Baikal surface sediments
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Chu, Chi-Hung, and 朱啓宏. "Accumulation and distribution of PAHs in marine plankton." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/496y2v.
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碩士國立東華大學
海洋生物多樣性及演化研究所
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As the lower trophic levels, plankton afford sufficient basic product to maintain the food web, especially phytoplankton not only play a primary producer but also a carrier of persist organic pollutions (POPs) from seawater into biota. The study simulated the field of plankton food chain to understand the accumulation and distribution of polycyclic aromatic hydrocarbons (PAHs) in phytoplankton and zooplankton at different points of exposure time. The plankton food chain constructed by phytoplankton (Tetraselmis chuii), rotifers (Brachionus sp.), and copepods (Apocyclops sp.), which cultured in a steady supply of PAHs gas purging system during 168 hours. The results show that PAHs accumulation in plankton could roughly divide into three sections: 0.2-1 hours, 1-24 hours, and 24-168 hours. The PAH concentrations in plankton variance at 0.2-1 hours and 1-24 hours, then approached study-state at 24-168 hours exposure. The low molecular weight PAHs (ACN, AC) in copepod were significantly higher than in rotifer and phytoplankton, but the high molecular weight PAHs (FA and PY) were significantly higher in phytoplankton, indicating that the plankton might have selectivity to PAHs. In principal component analysis (PCA), phytoplankton and zooplankton could significantly separated to two groups, among the PAHs accumulative part of rotifer and copepod were similar, demonstrating the PAH composition in plankton might be effected by trophic levels. In the relationship between bioconcentration factor (BCF) and PAHs hydrophobicity (Kow) in part of phytoplankton, rotifer and copepod, all of them show a great linear relationship. Compare the linear regression slopes of log BCF and log Kow between phytoplankton, rotifer and copepod, the significantly different results suggested that the cumulative pathway of PAHs were different in plankton. According to the biomagnification factor (BMF) to estimate PAHs accumulation through feeding, the low molecular weight PAHs (ACN, AC) might have risk of biomagnifications in plankton than high molecular weight PAHs.
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Brepohl, Daniela Christine [Verfasser]. "Fatty acids distribution in marine, brackish and freshwater plankton during mesocosm experiments / vorgelegt von Daniela Christine Brepohl." 2005. http://d-nb.info/975488422/34.
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Daigle, Remi. "THE INFLUENCE OF SWIMMING ON THE VERTICAL AND HORIZONTAL DISTRIBUTION OF MARINE INVERTEBRATE LARVAE." 2013. http://hdl.handle.net/10222/36295.
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This thesis aims to increase our understanding of mechanisms that influence larval dispersal in marine benthic invertebrates, particularly in the absence of strong oceanographic features (e.g. estuarine plumes, upwelling events, or markedly different water masses). Laboratory experiments identified behavioural mechanisms that regulate the vertical distribution of larvae in response to thermal stratification, and field studies in St. George’s Bay, Nova Scotia (NS), Canada, examined the relationship between larval abundance and physical variables (temperature, salinity, fluorescence, etc) and identified mechanisms that regulate larval distributions in situ. In the laboratory, I demonstrated that thermal stratification affects the vertical distribution of larvae by acting as a barrier to migration, or through temperature-dependent vertical swimming velocities. I also developed a random walk based model which highlighted that the key to successfully simulating larval response to temperature was 1) determining the temperature-dependent distribution of vertical swimming velocities and 2) the temporal autocorrelation in these velocities. In the field, the most striking pattern was that the larval distributions for species with similar swimming abilities were significantly correlated to one another at all scales (0.5 to 40 km). This suggests a common mechanism, related to larval swimming ability, which greatly influences the horizontal larval distribution. I found that the spatial scale of variability in larval distributions (~ 3 km) matches that in both the environmental variables and of coherent structures in current velocities (i.e. the tidal excursion). Results from an aggregation-diffusion model suggest that horizontal larval swimming could not be responsible for the observed level of aggregation in the larval horizontal distributions. I suggest that these horizontal patterns are the result of 1) an aggregative process (i.e. larvae swimming against a vertical current and maintaining their vertical position) and 2) a diffusive process which scales the aggregations to the scale of the coherent structures in current velocity (i.e. tidal excursion). In conclusion, this thesis increases our understanding of larval behaviour and its effects on larval dispersal. The results will be particularly useful to those who are interested in mechanisms regulate population connectivity, particularly those using bio-physical models to model dispersal trajectories.
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Lloyd, Michelle. "Patterns in the larval vertical distribution of marine benthic invertebrates in a shallow coastal embayment." 2011. http://hdl.handle.net/10222/14288.
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Processes during the meroplanktonic phase regulate population dynamics for many marine benthic invertebrates. I examined changes in vertical distribution of different meroplanktonic larvae in a coastal embayment during a stable period, at high temporal frequencies and spatial resolutions. Plankton samples were collected at 6 depths (3, 6, 9, 12, 18, 24 m) using a pump, every 2-h over a 36- and a 25-h period, during a spring and neap tide, respectively, concurrently with measures of temperature, salinity, fluorescence and current velocity. For 10 gastropod taxa, larval vertical distribution was mostly related to the thermal structure of the water column. Each of 7 taxonomic groups was found either exclusively near the surface, associated with the fluorescence maximum, or showed diel changes in distribution. These larvae that occupy different depths in the water column exhibit different dispersal potentials.Biogeographical data contained in this thesis will be submitted to the Oceanographic Biogeographic Information System (OBIS) and may be accessed on-line at http://www.iobis.org
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Doherty, Mary. "Distribution and diversity of planktonic ciliates: Patterns and processes." 2009. https://scholarworks.umass.edu/dissertations/AAI3379953.
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The nature and extent of microbial biodiversity remain controversial with persistent debates over patterns of distributions (i.e. cosmopolitanism vs. endemism) and the processes that structure these patterns (neutrality vs. selection). I used culture-independent approaches to address these issues focusing on two groups of ciliates, the Oligotrichia (Spirotrichea) and Choreotrichea (Spirotrichea). To assess the diversity of these ciliates, I designed primers specific to SSU rDNA of ciliates within these clades, and investigated (1) geographic and temporal distributions along three coastal sites in the Northwest Atlantic; (2) the relationship between ciliate communities in the benthos and the plankton along the New England coast; and (3) diversity in ciliate communities across an environmental gradient at six stations in Long Island Sound spanning the frontal region that separates the fresher Connecticut River outflow plume from the open Sound. Each collection had its own distinct assemblage of rare and abundant ciliate haplotypes, and genealogical analyses of my samples combined with published sequences from identified morphospecies reveal that haplotype diversity at these sites is greatest within the genus Strombidium, in the Oligotrichia. Clustering of phylogenetic types indicates that benthic assemblages of oligotrichs and choreotrichs appear to be more like those from spatially distinct benthic communities than the ciliate communities sampled in the water above them. Neither ciliate diversity nor species composition showed any clear relationship to measured environmental parameters (temperature, salinity, accessory pigment composition, and chorophyll), although I observed that diversity decreased moving from nearshore to offshore. I find no strong fit of my communities to log series, geometric, or log normal distributions, though one of the 3 clusters is most consistent with a log series distribution. These analyses suggest that Oligotrich and Choreotrich communities in coastal environments may be distributed in a neutral manner. I investigated the effectiveness of molecular approaches in characterizing ciliate diversity in my samples. Estimates of diversity based on molecular markers are similar to estimates from morphological observations for Choreotrich ciliates, but much greater for Oligotrich ciliates. Sediment and plankton subsamples differed in their robustness to repeated subsampling. Sediment gave variable estimates of diversity while plankton subsamples produced consistent results.
Books on the topic "Marine plankton – Vertical distribution"
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Hassett, R. Patrick. Seasonal, vertical, and horizontal distribution of four species of copepods around Oahu, Hawaii: Data report. [La Jolla, Calif.]: U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, [Southwest Fisheries Science Center, 1995.
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Boysen-Ennen, E. Zur Verbreitung des Meso- und Makrozooplanktons im Oberflächenwasser der Weddell See (Antarktis) =: On the distribution of meso- and macrozooplankton in the surface water of the Weddell Sea (Antarctica). Bremerhaven: Alfred-Wegener-Institut für Polar- und Meeresforschung, 1987.
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Arenovski, Andrea Lynn. The distribution, abundance and ecology of mixotrophic algae in marine and freshwater plankton communities. Woods Hole, Mass: Woods Hole Oceanographic Institution, Massachusetts Institute of Technology, 1994.
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), Bunn (N C. Spring plankton surveys of the Irish Sea in 2000: Hydrography and the distribution of fish eggs and larvae. Lowestoft [England]: The Centre, 2004.
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Bunn, N. Spring plankton surveys of the eastern Irish Sea in 2001, 2002 and 2003: Hydrography and the distribution of fish eggs and larvae. Lowestoft [England]: Centre for Environment, Fisheries and Aquaculture Science, 2004.
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Piatkowski, U. Zoogeographische Untersuchungen und Gemeinschaftsanalysen an antarktischem Makroplankton =: Zoogeographical investigations and community analyses on Antarctic macroplankton. Bremerhaven: Alfred-Wegener-Institut für Polar- und Meeresforschung, 1987.
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Klöser, Heinz. Verteilung von Mikroplankton-Organismen nord-westlich der Antarktischen Halbinsel unter dem Einfluss sich ändernder Umweltbedingungen im Herbst: = Distribution of microplankton organisms north and west of the Antarctic Peninsula according to changing ecological conditions in autumn. Bremerhaven: Alfred-Wegener-Institut für Polar- und Meeresforschung, 1990.
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Klöser, Heinz. Verteilung von Mikroplankton-Organismen nordwestlich der Antarktischen Halbinsel unter dem Einfluss sich ändernder Umweltbedingungen im Herbst =: Distribution of microplankton organisms north and west of the Antarctic Peninsula according to changing ecological conditions in autumn. Bremerhaven: Alfred-Wegener-Institut für Polar- und Meeresforschung, 1990.
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Richter, Claudio. Regional and seasonal variability in the vertical distribution of mesozooplankton in the Greenland Sea. Bremerhaven: Alfred-Wegener-Institut für Polar- und Meeresforschung, 1994.
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Boehlert, George W. Ichthyoplankton vertical distributions near Oahu, Hawaii, 1985-1986: Data report. [La Jolla, Calif.]: U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Southwest Fisheries Science Center, 1996.
Find full textBook chapters on the topic "Marine plankton – Vertical distribution"
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Titelman, Josefin, and Peter Tiselius. "Vertical distribution, grazing and egg production of calanoid copepods during winter-spring in Gullmarsfjorden." In Recruitment, Colonization and Physical-Chemical Forcing in Marine Biological Systems, 343–51. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-017-2864-5_28.
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Fransz, H. G. "Effects of Fresh Water Inflow on the Distribution, Composition and Production of Plankton in the Dutch Coastal Waters of the North Sea." In The Role of Freshwater Outflow in Coastal Marine Ecosystems, 241–49. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-70886-2_16.
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Vinogradov, M. E. "Some Problems of Vertical Distribution of Meso- and Macroplankton in the Ocean." In Advances in Marine Biology, 1–92. Elsevier, 1997. http://dx.doi.org/10.1016/s0065-2881(08)60015-2.
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Taylor, A. H., J. R. W. Harris, and J. Aiken. "The Interaction of Physical and Biological Processes in a Model of the Vertical Distribution of Phytoplankton Under Stratification." In Marine Interfaces Ecohydrodynamics, 313–30. Elsevier, 1986. http://dx.doi.org/10.1016/s0422-9894(08)71052-3.
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Sryberko, Andrii. "ANALYSIS OF THE THERMOHALINE STRUCTURE IN THE ACTIVE LAYER OF THE MARINE ENVIRONMENT ACCORDING TO THE CALCULATED HYDROPHYSICAL CHARACTERISTICS BASED ON REMOTE MEASUREMENTS (ON THE EXAMPLE OF THE BLACK SEA)." In European vector of development of the modern scientific researches. Publishing House “Baltija Publishing”, 2021. http://dx.doi.org/10.30525/978-9934-26-077-3-6.
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Today, one of the priority scientific directions in marine sciences is the study of the spatial distribution of hydrophysical characteristics in the marine environment by remote measurements methods. To studying the spatio-temporal variability of water temperature and salinity in the active layer of the marine environment, it is necessary to use the data of their vertical and spatial distribution. Today there does not exist an easy way to get a in situ data for the analysis of the thermohaline structure in the marine environment. Indirect definitions of the vertical and spatial distribution of water temperature and salinity through the development of various methods for the calculation of thermohaline characteristics are used to date. Main purpose of this work is to study the thermohaline structure in the active layer of the Black Sea according to the calculated hydrophysical characteristics based on satellite and hydroacoustic data. The study of the vertical distribution of water temperature and salinity in the Black Sea was carried out in the deep-water part sea at standard levels (0, 10, 20, 25, 30, 50 meters) in the spring –autumn period. This area of research is represented by the highest number of measurements and is included in the Main Black Sea current zone. The calculations of thermohaline characteristics in the marine environment are based on the original methods of calculating the vertical distribution of water temperature, sound speed and salinity of water by satellite and hydroacoustic data. These methods were developed in the State Institute “Hydroacoustic Branch of Institute of Geophysics by S.I. Subbotin name of the National Academy of Sciences of Ukraine”. Mathematical and physical-statistical methods of calculation were used in the developed methods. For the efficiency of calculations an Automated Program Complex (APC) for calculating the vertical distribution of temperature and salinity fields in the marine environment by satellite and hydroacoustic data has been developed and tested on the example of the Black Sea. The initial data for the calculations using the APC are only daily satellite data of the sea surface temperature. Based on the results of calculations of the APC, maps of the vertical distribution of temperature and salinity of water on zonal and meridional sections in the Black Sea in the period of spring – autumn 2018 were developed. Analysis of the results of calculations of the vertical distribution of thermohaline characteristics made it possible to identify the main features in these distributions. The features of the spatial-temporal distribution of thermohaline parameters have been analysed. The confirmation of the state of the thermohaline regime inherent in the Black Sea in the warm season was obtained. The results of calculations of the vertical distribution of thermohaline characteristics in the Black Sea deep-water area on the basis of satellite and hydroacoustic data using the developed methods showed the possibility and expediency of their application in the layer 0-50 meters in the period May-October for a detailed analysis of the state of the thermohaline structure. The developed methods and principles of building an the APC for calculation of vertical distribution of temperature and salinity fields of water according to satellite and hydroacoustic data can be applied for analysis and monitoring of others water area of the World Ocean taking into account their hydrological conditions.
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"Early Life History of Fishes in the San Francisco Estuary and Watershed." In Early Life History of Fishes in the San Francisco Estuary and Watershed, edited by Andrew K. Rockriver. American Fisheries Society, 2004. http://dx.doi.org/10.47886/9781888569599.ch7.
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<em>Abstract.</em>—The goal of this study was to determine if the vertical distribution of larval delta smelt <em>Hypomesus transpacificus </em>and striped bass <em>Morone saxatilis </em>was affected by tidal stage and diel period. Delta smelt and striped bass have similar early life histories in that their larvae drift downstream from freshwater spawning habitats to brackish water rearing habitats. Little is known on whether the larvae undergo a vertical migration as they move downstream. Conical plankton nets were used to collect larval fishes from the surface, middle, and bottom sections of the main channels of the Sacramento and San Joaquin rivers. Samples were collected over six paired day–night cruises. Approximately 45,000 fish were collected; 82% were striped bass and 2% were delta smelt. More delta smelt were caught at night than during the day, and more at middle depth than surface or bottom. Very few striped bass were found at surface during day; most were caught at middle depth. Both species were fairly dispersed throughout the water column at night. Although striped bass larvae appear to undergo a small surface to middepth migration, this study indicates that larval delta smelt and striped bass do not undergo a mass diel or tidal vertical migration as they drift down the Sacramento and San Joaquin rivers.
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Dawidowicz, Piotr, and Joanna Pijanowska. "Diel Vertical Migration of Aquatic Crustaceans—Adaptive Role, Underlying Mechanisms, and Ecosystem Consequences." In Life Histories, 232–57. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780190620271.003.0009.
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The phenomenon of diel vertical migration (DVM) of planktonic crustaceans, recognized by biologists for at least 2 centuries, is a special case of habitat selection behavior by pelagic animals, with their depth preference changing over a diel cycle in a way that prevents encounters with visually oriented predators (mostly fish). Migrating populations usually move toward cold, dark deep-water strata deprived of algal food when there is sufficient ambient light and move back to food-rich and warm surface waters after dusk. DVM has been recognized in pelagic representatives of all aquatic phyla of the animal kingdom and is considered the most massive diel biomass displacement on Earth. DVM can be observed in nearly all lentic freshwater and marine environments. As zooplankton occupy the central position in pelagic food webs, their massive migrations dramatically affect ecological functioning of offshore biota, particularly the efficiency of primary production utilization, energy flow, and biogeochemical pathways of essential nutrients such as carbon fluxes. The phenomenon of DVM is perhaps the most suitable for quantitative description and the major environmental factors underlying the fitness consequences of DVM, including vertical gradients of light intensity (predation risk), temperature related metabolic rates, food concentration (growth and fecundity), and others, are easy to monitor track in the field and to manipulate in laboratory systems. DVM, as inducible behavior, can be experimentally manipulated, both in the field and in the laboratory, which, in turn, makes it possible to design experiments convenient for testing specific hypotheses on various proximate and ultimate factors underlying this behavior. These characteristics make DVM suitable for investigating the evolution of animal behavior, its adaptive value, and ecosystem consequences. In the fondest memory of our friend Konrad Ciechomski with whom we made, years ago, our first steps into the world of plankton migrations.
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"Pacific Salmon: Ecology and Management of Western Alaska’s Populations." In Pacific Salmon: Ecology and Management of Western Alaska’s Populations, edited by Katherine W. Myers, Robert V. Walker, Nancy D. Davis, Janet L. Armstrong, and Masahide Kaeriyama. American Fisheries Society, 2009. http://dx.doi.org/10.47886/9781934874110.ch12.
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<em>Abstract.</em>—Data from high seas tagging experiments (external tags, coded-wire tags, electronic data storage tags) provide the only direct information on the distribution, biology, and ecology of immature and maturing Arctic-Yukon-Kuskokwim (AYK) salmon (<em>Oncorhynchus </em>spp.) migrating in the North Pacific Ocean and Bering Sea. Variation in the spatial and temporal distribution of tagging effort largely reflects changes in international salmon treaty research priorities over the past 52 years (1954–2006). Results of tagging studies indicate that in spring maturing AYK pink <em>O. gorbuscha </em>and coho <em>O. kisutch </em>salmon and immature and maturing AYK sockeye <em>O. nerka </em>and chum <em>O. keta </em>salmon are distributed primarily in the northeastern North Pacific Ocean and Gulf of Alaska, and in summer their distribution shifts to the west in the Gulf of Alaska and to the north and west in the Bering Sea. Immature and maturing AYK Chinook salmon <em>O. tshawytscha </em>are distributed in the eastern Bering Sea in winter, and immature Chinook salmon are distributed in the central and western Bering Sea in summer. Depth data from electronic tags indicated that Chinook and chum salmon have the deepest vertical distributions among the salmon species. Swimming depths might remain relatively constant across water masses and ocean areas. Bioenergetic simulations indicated that AYK salmon experiencing increased mean summer temperatures in the Bering Sea could suffer reduced growth at all age-maturity stages unless prey availability or prey energy density increased commensurately. Published conceptual models of the high seas distribution and migration patterns of AYK salmon need to be updated with new information from tagging, scale pattern, and genetic studies. New dynamic models would be useful for predicting climate-induced changes in carrying capacity, growth and survival, exploitation by marine fisheries, and timing of adult returns to the AYK region.
Conference papers on the topic "Marine plankton – Vertical distribution"
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Rubtsova, Svetlana, Svetlana Rubtsova, Natalya Lyamina, Natalya Lyamina, Aleksey Lyamin, and Aleksey Lyamin. "ANALYSIS OF THE FUNCTIONING OF MARINE ECOSYSTEMS ON CHANGING THE PARAMETERS OF THE BIOLUMINESCENCE FIELD ON THE CRIMEAN BLACK SEA SHELF." In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.21610/conferencearticle_58b43168bfc21.
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The concept of a new approach to environmental assessment is offered in the system of integrated management of the resource and environmental safety of the coastal area of the Black Sea. The studies of the season and daily changeability in the bioluminescence field in the Sevastopol coastal waters has been conducted. For the first time considerable differences in the bioluminescence field seasonal changes in the surface and deep water layers and the reasons conditioning this phenomenon have been shown, using a method of multidimensional statistical analysis. The bioluminescence field vertical profile change in the Black sea coastal waters in the autumn period at night has been studied. It has been shown that according to the character of bioluminescence parameters dynamics a water column can be divided into layers: upper (0 – 35 m) and deep water (36 – 60 m). It has been revealed that life rhythms of the plankton community are the main reason for the bioluminescence field intensity variability. It has been revealed that 14-hour periodicity of the bioluminescence field is related to the changes in light and its variations with 2,5…4,5 hours are conditioned by planktonts endogenous daily rhythms. And here biotic factors effect mostly periodicity of the bioluminescence field intensity increase and fall down at the dark time of the day. Abiotic factors are of less importance in circadian rhythmic of the bioluminescence field in the neritic zone.
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Rubtsova, Svetlana, Svetlana Rubtsova, Natalya Lyamina, Natalya Lyamina, Aleksey Lyamin, and Aleksey Lyamin. "ANALYSIS OF THE FUNCTIONING OF MARINE ECOSYSTEMS ON CHANGING THE PARAMETERS OF THE BIOLUMINESCENCE FIELD ON THE CRIMEAN BLACK SEA SHELF." In Managing risks to coastal regions and communities in a changing world. Academus Publishing, 2017. http://dx.doi.org/10.31519/conferencearticle_5b1b9387ec5c97.58539127.
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The concept of a new approach to environmental assessment is offered in the system of integrated management of the resource and environmental safety of the coastal area of the Black Sea. The studies of the season and daily changeability in the bioluminescence field in the Sevastopol coastal waters has been conducted. For the first time considerable differences in the bioluminescence field seasonal changes in the surface and deep water layers and the reasons conditioning this phenomenon have been shown, using a method of multidimensional statistical analysis. The bioluminescence field vertical profile change in the Black sea coastal waters in the autumn period at night has been studied. It has been shown that according to the character of bioluminescence parameters dynamics a water column can be divided into layers: upper (0 – 35 m) and deep water (36 – 60 m). It has been revealed that life rhythms of the plankton community are the main reason for the bioluminescence field intensity variability. It has been revealed that 14-hour periodicity of the bioluminescence field is related to the changes in light and its variations with 2,5…4,5 hours are conditioned by planktonts endogenous daily rhythms. And here biotic factors effect mostly periodicity of the bioluminescence field intensity increase and fall down at the dark time of the day. Abiotic factors are of less importance in circadian rhythmic of the bioluminescence field in the neritic zone.
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Helmers, Jens B., Hui Sun, Tormod Landet, and Torgrim Driveklepp. "Stochastic Analysis of Impact Loads on Marine Structures." In ASME 2012 31st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/omae2012-83849.
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An efficient Monte Carlo method is developed to perform the stochastic analysis of slamming loads on marine structures. The probability distribution of the maximum impact force during slamming is established for a given stationary sea state. The method is demonstrated by using a uniform wedge and Wagner’s flat plate theory. Stochastic effects related to deadrise angle, flow separation from the knuckle, vertical position of the structure, vertical motion and roll motion are investigated. The statistics of other parameters such as the duration of the slamming event and the maximum penetration of the structure into water are also assessed.
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Li, Ye, and Sander M. Calisal. "Preliminary Results of a Vortex Method for Stand-Alone Vertical Axis Marine Current Turbine." In ASME 2007 26th International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2007. http://dx.doi.org/10.1115/omae2007-29708.
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Tidal power technology has been dwarfed once to take hold in the late 1970’s, because the early generations were expensive at small scale and some applications (such as barrages) had negative environmental impacts. In a similar working manner as a wind turbine, a tidal current turbine has been recognized as a promising ocean energy conversion device in the past two decades. However, the industrialization process is still slow. One of the important reasons is lack of comprehensive turbine hydrodynamics analysis which can not only predict turbine power but also assess impacts on the surrounding areas. Although a lot can be learned from the marine propeller or the wind turbine studies, a systematic hydrodynamics analysis on a vertical axis tidal current turbine has not been reported yet. In this paper, we employed vortex method to calculate the performance of stand-alone vertical axis tidal turbine in term of power efficiency, torque and forces. This method focuses on power prediction, hydrodynamics analysis and design, which can provide information for turbines distribution planning in a turbine farm and other related studies, which are presented in Li and Calisal (2007), a companion paper in the conference. In this method, discrete vortex method is the core for numerical calculation. Free vortex wake structure, nascent vortex and vortex decay mechanism are discussed in detail. Good agreements in turbine efficiency comparison are obtained with both the newly-designed tidal turbine test in a towing tank and early wind turbine test.
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Dehghani-sanij, Alireza, Yuri S. Muzychka, and Greg F. Naterer. "Analysis of Ice Accretion on Vertical Surfaces of Marine Vessels and Structures in Arctic Conditions." In ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/omae2015-41306.
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The phenomenon of icing in cold climates is a challenging problem of engineering analysis, which involves heat transfer, phase change and multiphase flow with water droplets. This phenomenon has an important impact on the performance and operation of marine vessels, offshore structures, and others such as wind turbines, power lines, and aircraft surfaces. In this paper, a predictive icing model for large vertical surfaces of a marine vessel is developed theoretically. The total flux of sea-spray, including wave spray and wind spray, is analyzed during the spray process. By using heat, mass and salt concentration balances, the freezing fraction, temperature distribution, ice layer thickness, and liquid film thickness are determined. The results are compared with the numerical and experimental results of other studies. Good agreement between the theoretical predictions and other results demonstrates the improved accuracy of the proposed method over past models.
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Demetrashvili, Demuri, Vepkhia Kukhalashvili, Diana Kvaratskhelia, and Aleksandre Surmava. "MARINE FORECAST FOR THE EASTERNMOST PART OF THE BLACK SEA." In GEOLINKS Conference Proceedings. Saima Consult Ltd, 2021. http://dx.doi.org/10.32008/geolinks2021/b1/v3/50.
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Modelling and forecasting of dynamic processes and distribution of various substances of anthropogenic and natural origin in coastal and shelf zones of the seas and oceans are of great interest due to the high anthropogenic load of these zones. The aim of this paper is to present some examples of modelling and short-term forecasting of dynamic fields – the current, temperature and salinity in the easternmost Black Sea covering Georgian sector of the Black Sea and adjacent water area using a high-resolution regional model of the Black Sea dynamics. The z-level regional model is based on a full system of ocean hydro-thermodynamics equations and is nested in the basin-scale model of the Black Sea dynamics of Marine Hydrophysical Institute (Sevastopol). To solve the model equation system, a numerical algorithm based on the splitting method is used. Calculations show that circulation processes in the easternmost water area of the Black Sea are characterized by a permanent alternation of different circulation modes with the formation of mesoscale and submesoscale eddies throughout the year, which significantly affect the formation of thermohaline fields; atmospheric wind forcing substantially determines not only the peculiarities of the sea surface horizontal circulation, also the vertical structure of the current field.
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Huerta Lo´pez, Carlos I., Jay Pulliam, Kenneth H. Stokoe, Jose´ M. Roe¨sset, and Celestino Valle-Molina. "Spectral Characteristics of Earthquakes Recorded on the Gulf of Me´xico Seafloor and Modeling of Soft Marine Sediments." In ASME 2003 22nd International Conference on Offshore Mechanics and Arctic Engineering. ASMEDC, 2003. http://dx.doi.org/10.1115/omae2003-37504.
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The overall goal of this work was to develop a cost-effective method of characterizing offshore geotechnical sites in deep water. The generic approach was to place an ocean bottom seismograph on the seafloor and record ambient noise and distant earthquakes over periods of a month or more. Horizontal-to-vertical (H/V) spectral ratios were then calculated and used to characterize the local sediment response in terms of the distribution of motions with their respective resonant frequencies. One-dimensional wave propagation modeling using the stiffness matrix method was used to estimate sediment properties (mainly layering, shear stiffness, density and material damping) by matching the resonant frequency and amplification factors of the shallow sediment layers. The resulting sediment properties fall well within the expected range, indicating the potential of the proposed exploration approach for characterizing deep water sites.
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Jindal, Rahul, and Nabanita Datta. "Free Dry and Wet Vibration of 2-Way Tapered Hollow Marine Rudder With Non-Classical Pivot: Theoretical Study." In ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/omae2015-41106.
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A theoretical analysis of free dry and wet vibration of a trapezoidal, 2-way tapered, marine spade rudder, is presented. The rudder is considered as a hollow Kirchhoff’s plate, with the chord section as a NACA profile. The chord length and the thickness taper from the top to the bottom, over the vertical span. The rudder is pivoted at the top, with the pivot behind the leading edge. The pivot is modeled as a combination of a translational and a rotational spring, in order to include the rigid body modes of the rudder vibration. The span-wise and chord-wise non-uniform beam vibration is first analyzed by the Rayleigh-Ritz method, in order to establish the non-uniform beam mode shapes. The span-wise beam is a linearly tapered vertical cantilever, with non-classical edge at the top and free at the bottom. The chord-wise section is a 2-span beam with the ends free, and four continuity conditions at the pivot. The non-uniform mode shapes, in either direction, are a weighted summation of the uniform beam mode shapes, which also satisfy the boundary/continuity conditions. They now act as admissible spatial functions to the plate vibration, which is analyzed by the Galerkin’s method. Eigenvalue analysis generates the plate natural frequencies. A weighted superposition, of the product of the beam mode shapes, in either direction, generates the plate mode shapes. Alternately, uniform beam mode shapes are used as admissible functions into the Galerkin’s method for the plate natural frequencies and mode shapes. The natural frequencies are generated for various positions of the rudder stock along the chord length. The pivot conditions (in both translational and rotational rigid body degree of freedom) influence the prominence of the rigid body mode shapes. The natural frequencies are analyzed for various pivot fixities, taper ratios, and aspect ratios of the plate. This is followed by the wet vibration analysis of the rudder. First, 2D strip theory is used to generate the added mass of each chord section. Constant strength source distribution technique is used to generate the added mass in sway and yaw of a 2D aerofoil. Each flexural and torsional mode is associated with its own added mass. Various empirical corrections are done to account for the 3D flow. Finally, 3D panel method is used to generate the modal added masses, and hence the wet natural frequencies. The added mass coefficient is generated for various aerofoil fineness ratios, pivot fixities, taper ratios, and aspect ratios of the plate.
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Madu, Osita Robinson, Jerry Orrelo Athoja, Amarachi Queen Kalu, and Obi Mike Onyekonwu. "Integrated Approach to Geostatistics For Optimal Reservoir Properties Distribution – Case Study of X-Reservoir in Niger Delta Basin." In SPE Nigeria Annual International Conference and Exhibition. SPE, 2021. http://dx.doi.org/10.2118/207116-ms.
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Abstract In-depth knowledge of geostatistical analysis, environment of deposition and reservoir facies types is important for optimal distribution of reservoir properties across the reservoir grid. Geostatistics is a veritable tool that is quantitatively used to model spatial continuity, anisotropy direction and capture reservoir heterogeneity for optimal distribution of reservoir properties. When spatial continuity and heterogeneity level of the reservoir are adequately understood and modeled, representative property distribution becomes possible. In the face of limited well data, modeling major and minor directions of horizontal variogram is highly impaired and it becomes difficult to adequately distribute properties within the reservoir grid with enough control. This study is focused on the integration of seismic data, core data, well logs and geological knowledge to carry out geostatistical analysis to optimally distribute facies, porosity and permeability properties within the grid. The degree of reservoir heterogeneity was determined quantitatively using semivariogram and Lorenz plots of core porosity and permeability data. Variogram map generated from seismic attribute was used in combination with the sparse well data points to determine the horizontal variogram. The available well data was adequate enough to model the vertical variogram. The environment of deposition was interpreted as lower to upper shoreface with channel deposits and some shallow marine influence. The properties were normal-scored and modeled with the determined variogram parameters while biasing them with facies. Results of the semivariogram and Lorenz plots showed that the reservoir is fairly heterogenous in terms of spatial continuity. Major direction of the geological continuity is in the Northeast-Southwest direction while the minor direction is orthogonal to it. Final result of the modeled properties was in consonance with the facies types described from the environment of deposition.
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Ingvarsdo´ttir, Hildur, Carl Ollivier-Gooch, and Sheldon I. Green. "Numerical Experiments for Flow Around a Ducted Tip Hydrofoil." In ASME 2002 Pressure Vessels and Piping Conference. ASMEDC, 2002. http://dx.doi.org/10.1115/pvp2002-1563.
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The performance and cavitation characteristics of marine propellers and hydrofoils are strongly affected by tip vortex behavior. A number of previous computational studies have been done on tip vortices, both in aerodynamic and marine applications. The focus, however, has primarily been on validating methods for prediction and advancing the understanding of tip-vortex formation in general, rather than showing effects of tip modifications on tip vortices. Studies of the most relevance to the current work include computational studies by Dacles-Mariani et al. (1995) and Hsiao and Pauley (1998, 1999). Daeles-Mariani et al. carried out interactively a computational and experimental study of the wingtip vortex in the near field using a full Navier-Stokes simulation, accompanied with the Baldwin-Barth turbulence model. Although they showed improvement over numerical results obtained by previous researchers, the tip vortex strength was underpredicted. Hsiao and Pauley (1998) studied the steady-state tip vortex flow over a finite-span hydrofoil, also using the Baldwin-Barth turbulence model. They were able to achieve good agreement in pressure distribution and oil flow pattern with experimental data and accurately predict vertical and axial velocities of the tip vortex core within the near-field region. Far downstream, however, the computed flow field was overly diffused within the tip vortex core. Hsiao and Pauley (1999) also carried out a computational study of the tip vortex flow generated by a marine propeller. The general characteristics of the flow were well predicted but the vortex core was again overly diffused.
Reports on the topic "Marine plankton – Vertical distribution"
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Bridges, Todd, Sandra Newell, Alan Kennedy, David Moore, Upal Ghosh, Trevor Needham, Huan Xia, Kibeum Kim, Charles Menzie, and Konrad Kulacki. Long-term stability and efficacy of historic activated carbon (AC) deployments at diverse freshwater and marine remediation sites. Engineer Research and Development Center (U.S.), November 2020. http://dx.doi.org/10.21079/11681/38781.
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A number of sites around the United States have used activated carbon (AC) amendments to remedy contaminated sediments. Variation in site-specific characteristics likely influences the long-term fate and efficacy of AC treatment. The long-term effectiveness of an AC amendment to sediment is largely unknown, as the field performance has not been monitored for more than three years. As a consequence, the focus of this research effort was to evaluate AC’s long-term (6–10 yr) performance. These assessments were performed at two pilot-scale demonstration sites, Grasse River, Massena, New York and Canal Creek, Aberdeen Proving Ground (APG), Aberdeen, Maryland, representing two distinct physical environments. Sediment core samples were collected after 6 and 10 years of remedy implementation at APG and Grasse River, respectively. Core samples were collected and sectioned to determine the current vertical distribution and persistence of AC in the field. The concentration profile of polychlorinated biphenyls (PCBs) in sediment pore water with depth was measured using passive sampling. Sediment samples from the untreated and AC-treated zones were also assessed for bioaccumulation in benthic organisms. The data collected enabled comparison of AC distribution, PCB concentrations, and bioaccumulation measured over the short- and long-term (months to years).
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Lenz, Mark. RV POSEIDON Fahrtbericht / Cruise Report POS536/Leg 1. GEOMAR, October 2020. http://dx.doi.org/10.3289/geomar_rep_ns_56_2020.
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DIPLANOAGAP: Distribution of Plastics in the North Atlantic Garbage Patch Ponta Delgada (Portugal) – Malaga (Spain) 17.08. – 12.09.2019 The expedition POS 536 is part of a multi-disciplinary research initiative of GEOMAR investigating the origin, transport and fate of plastic debris from estuaries to the oceanic garbage patches. The main focus will be on the vertical transfer of plastic debris from the surface and near-surface waters to the deep sea and on the processes that mediate this transport. The obtained data will help to develop quantitative models that provide information about the level of plastic pollution in the different compartments of the open ocean (surface, water column, seafloor). Furthermore, the effects of plastic debris on marine organisms in the open ocean will be assessed. The cruise will provide data about the: (1) abundance of plastic debris with a minimum size of 100 μm as well as the composition of polymer types in the water column at different depths from the sea surface to the seafloor including the sediment, (2) abundance and composition of plastic debris in organic aggregates (“marine snow”), (3) in pelagic and benthic organisms (invertebrates and fish) and in fecal pellets, (4) abundance and the identity of biofoulers (bacteria, protozoans and metazoans) on the surface of plastic debris from different water depths, (5) identification of chemical compounds (“additives”) in the plastic debris and in water samples.