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1
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.
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Buitenhuis, E. T., M. Vogt, R. Moriarty, N. Bednaršek, S. C. Doney, K. Leblanc, C. Le Quéré, et al. "MAREDAT: towards a world atlas of MARine Ecosystem DATa." Earth System Science Data 5, no. 2 (July 12, 2013): 227–39. http://dx.doi.org/10.5194/essd-5-227-2013.
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Abstract. We present a summary of biomass data for 11 plankton functional types (PFTs) plus phytoplankton pigment data, compiled as part of the MARine Ecosystem biomass DATa (MAREDAT) initiative. The goal of the MAREDAT initiative is to provide, in due course, global gridded data products with coverage of all planktic components of the global ocean ecosystem. This special issue is the first step towards achieving this. The PFTs presented here include picophytoplankton, diazotrophs, coccolithophores, Phaeocystis, diatoms, picoheterotrophs, microzooplankton, foraminifers, mesozooplankton, pteropods and macrozooplankton. All variables have been gridded onto a World Ocean Atlas (WOA) grid (1° × 1° × 33 vertical levels × monthly climatologies). The results show that abundance is much better constrained than their carbon content/elemental composition, and coastal seas and other high productivity regions have much better coverage than the much larger volumes where biomass is relatively low. The data show that (1) the global total heterotrophic biomass (2.0–4.6 Pg C) is at least as high as the total autotrophic biomass (0.5–2.4 Pg C excluding nanophytoplankton and autotrophic dinoflagellates); (2) the biomass of zooplankton calcifiers (0.03–0.67 Pg C) is substantially higher than that of coccolithophores (0.001–0.03 Pg C); (3) patchiness of biomass distribution increases with organism size; and (4) although zooplankton biomass measurements below 200 m are rare, the limited measurements available suggest that Bacteria and Archaea are not the only important heterotrophs in the deep sea. More data will be needed to characterise ocean ecosystem functioning and associated biogeochemistry in the Southern Hemisphere and below 200 m. Future efforts to understand marine ecosystem composition and functioning will be helped both by further archiving of historical data and future sampling at new locations. Microzooplankton database: doi:10.1594/PANGAEA.779970 All MAREDAT databases: http://www.pangaea.de/search?&q=maredat
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Moriarty, R., and T. D. O'Brien. "Distribution of mesozooplankton biomass in the global ocean." Earth System Science Data Discussions 5, no. 2 (September 3, 2012): 893–919. http://dx.doi.org/10.5194/essdd-5-893-2012.
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Abstract. Mesozooplankton are cosmopolitan within the sunlit layers of the global ocean. They are important in the classical food web, having a significant feedback to primary production through their consumption of phytoplankton and microzooplankton. They are also the primary contributor to vertical particle flux in the oceans. Through both they affect the biogeochemical cycling of carbon and other nutrients in the oceans. Little, however, is known about their global distribution and biomass. While global maps of mesozooplankton biomass do exist in the literature they are usually in the form of hand-drawn maps and the original data associated with these maps are not readily available. The dataset presented in this synthesis has been in development since the late 1990's, is an integral part of the Coastal & Oceanic Plankton Ecology, Production, & Observation Database (COPEPOD), and is now also part of a wider community effort to provide a global picture of carbon biomass data for key plankton functional types, in particular to support the development of marine ecosystem models. A total of 153 163 biomass values were collected, from a variety of sources, for mesozooplankton. Of those 2% were originally recorded as dry mass, 26% as wet mass, 5% as settled volume, and 68% as displacement volume. Using a variety of non-linear biomass conversions from the literature, the data have been converted from their original units to carbon biomass. Depth-integrated values were then used to calculate mesozooplankton global biomass. Global mesozooplankton biomass, to a depth of 200 m, had a mean of 5.9 μg C l−1, median of 2.7 μg C l−1 and a standard deviation of 10.6 μg C l−1. The global annual average estimate of mesozooplankton, based on the median value, was 0.19 Pg C. Biomass was highest in the Northern Hemisphere, but the general trend shows a slight decrease from polar oceans to temperate regions with values increasing again in the tropics. Gridded dataset http://doi.pangaea.de/10.1594/PANGAEA.785501x.
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Massana, R., A. E. Murray, C. M. Preston, and E. F. DeLong. "Vertical distribution and phylogenetic characterization of marine planktonic Archaea in the Santa Barbara Channel." Applied and environmental microbiology 63, no. 1 (1997): 50–56. http://dx.doi.org/10.1128/aem.63.1.50-56.1997.
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Firdaus, Mochamad Ramdhan, Nurul Fitriya, Praditya Avianto, Hanif Budi Prayitno, and A'an Johan Wahyudi. "Plankton community in the western waters of North-Sumatera during the onset monsoon of Asian winter." Marine Research in Indonesia 45, no. 1 (June 30, 2020): 1–12. http://dx.doi.org/10.14203/mri.v45i1.565.
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The western waters of North-Sumatera experience dynamic environmental changes during the onset monsoon of the Asian winter. Those changes certainly will affect the distribution of marine organisms, especially the plankton. Plankton is the foundation of the aquatic food chain and plays an important role as the entry gate of solar energy to the water trophic systems. This study aims to investigate the plankton community and its correlation with the environmental factors during the onset monsoon of the Asian winter. Plankton samples were collected, along with water samples and in-situ measurement for environmental parameters determination from western waters of North-Sumatera (95°E – 93°N) in November-December 2017. Plankton samples were taken by vertically hauling (500 m) using Modified Twin Plankton Net with 80 µm mesh size for phytoplankton and 300 µm for zooplankton. Temperature, salinity, and density of waters were measured using CTD SBE 911 – Plus. The nutrients, including orthophosphate, nitrate, and silicate, measured using autoanalyzer Skalar SAN++. Thirty genera of phytoplankton and 44 taxa groups of zooplankton were found. The phytoplankton community dominated by Thallassionema, while the zooplankton dominated by Calanoida. There was a difference in the composition of plankton communities between the north and south parts of the study area. It was probably influenced by different water masses between those two regions indicated by the dissimilarity of their water characteristics. Based on the analysis of the T-S diagram, it is likely that the north community influenced by Bengal Bay Water while the south community influenced by the Indian Equatorial Water.
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Buitenhuis, E. T., M. Vogt, R. Moriarty, N. Bednaršek, S. C. Doney, K. Leblanc, C. Le Quéré, et al. "MAREDAT: towards a World Ocean Atlas of MARine Ecosystem DATa." Earth System Science Data Discussions 5, no. 2 (November 23, 2012): 1077–106. http://dx.doi.org/10.5194/essdd-5-1077-2012.
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Abstract. We present a summary of biomass data for 11 Plankton Functional Types (PFTs) plus phytoplankton pigment data, compiled as part of the MARine Ecosystem biomass DATa (MAREDAT) initiative. The goal of the MAREDAT initiative is to provide global gridded data products with coverage of all biological components of the global ocean ecosystem. This special issue is the first step towards achieving this. The PFTs presented here include picophytoplankton, diazotrophs, coccolithophores, Phaeocystis, diatoms, picoheterotrophs, microzooplankton, foraminifers, mesozooplankton, pteropods and macrozooplankton. All variables have been gridded onto a World Ocean Atlas (WOA) grid (1° × 1° × 33 vertical levels × monthly climatologies). The data show that (1) the global total heterotrophic biomass (2.0–6.4 Pg C) is at least as high as the total autotrophic biomass (0.5–2.6 Pg C excluding nanophytoplankton and autotrophic dinoflagellates), (2) the biomass of zooplankton calcifiers (0.9–2.3 Pg C) is substantially higher than that of coccolithophores (0.01–0.14 Pg C), (3) patchiness of biomass distribution increases with organism size, and (4) although zooplankton biomass measurements below 200 m are rare, the limited measurements available suggest that Bacteria and Archaea are not the only heterotrophs in the deep sea. More data will be needed to characterize ocean ecosystem functioning and associated biogeochemistry in the Southern Hemisphere and below 200 m. Microzooplankton database: doi:10.1594/PANGAEA.779970.
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Vedenin, Andrey A., Eteri I. Musaeva, Daria N. Zasko, and Alexander L. Vereshchaka. "Zooplankton communities in the Drake Passage through environmental boundaries: a snapshot of 2010, early spring." PeerJ 7 (November 7, 2019): e7994. http://dx.doi.org/10.7717/peerj.7994.
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Background Spatial distribution of zooplankton communities influenced by various environmental factors is always important for understanding pelagic ecosystems. The area of the Drake Passage (Southern Ocean) is of particular interest owing to the high spatial and temporal variability of hydrological parameters affecting marine fauna. This study provides a survey of zooplankton composition and spatial distribution along a transect in the Drake Passage sampled during the 31th Cruise of RV “Akademik Sergey Vavilov” in November, 2010. The main aim was to trace the main regularities in spatial zooplankton structure and its relationships with the environmental parameters. Methodology A total of 43 vertical hauls from the surface to 1,000 m depth were made at 13 stations using the Juday plankton net. 60 taxa were recorded, abundance and biomass of each were assessed. Environmental parameters including temperature, salinity, depth, horizontal distance between stations and surface chlorophyll concentration were tested as environmental factors possibly explaining plankton distribution. Results Higher zooplankton abundance and biomass with lower diversity were observed near the Polar Front. Cluster analysis revealed five different groups of zooplankton samples, four of which were arranged mostly by depth. Along the transect within the 1,000 m depth range, the qualitative taxonomical composition differed significantly with depth and to some extent differed also among horizontal hydrological regimes, while the quantitative structure of the communities (abundance of taxa) was mainly determined by depth. Plankton assemblages within the upper 300-m layer depended on hydrological fronts. Abundance of dominant taxa as well as total zooplankton abundance showed a clear correlation with depth, salinity and surface chlorophyll concentration. Some taxa also showed correlations with temperature and latitude. Between the stations the similarity in zooplankton structure was clearly dependent on the distance among them which indicates an importance of latitudinal gradient. Surface chlorophyll concentration was not correlated with zooplankton biomass, which can be explained by the uncompleted seasonal migrations of zooplankton from deeper waters in early spring.
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Moriarty, R., and T. D. O'Brien. "Distribution of mesozooplankton biomass in the global ocean." Earth System Science Data 5, no. 1 (February 12, 2013): 45–55. http://dx.doi.org/10.5194/essd-5-45-2013.
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Abstract. Mesozooplankton are cosmopolitan within the sunlit layers of the global ocean. They are important in the pelagic food web, having a significant feedback to primary production through their consumption of phytoplankton and microzooplankton. In many regions of the global ocean, they are also the primary contributors to vertical particle flux in the oceans. Through both they affect the biogeochemical cycling of carbon and other nutrients in the oceans. Little, however, is known about their global distribution and biomass. While global maps of mesozooplankton biomass do exist in the literature, they are usually in the form of hand-drawn maps for which the original data associated with these maps are not readily available. The dataset presented in this synthesis has been in development since the late 1990s, is an integral part of the Coastal and Oceanic Plankton Ecology, Production, and Observation Database (COPEPOD), and is now also part of a wider community effort to provide a global picture of carbon biomass data for key plankton functional types, in particular to support the development of marine ecosystem models. A total of 153 163 biomass values were collected, from a variety of sources, for mesozooplankton. Of those 2% were originally recorded as dry mass, 26% as wet mass, 5% as settled volume, and 68% as displacement volume. Using a variety of non-linear biomass conversions from the literature, the data have been converted from their original units to carbon biomass. Depth-integrated values were then used to calculate an estimate of mesozooplankton global biomass. Global epipelagic mesozooplankton biomass, to a depth of 200 m, had a mean of 5.9 μg C L−1, median of 2.7 μg C L−1 and a standard deviation of 10.6 μg C L−1. The global annual average estimate of mesozooplankton in the top 200 m, based on the median value, was 0.19 Pg C. Biomass was highest in the Northern Hemisphere, and there were slight decreases from polar oceans (40–90°) to more temperate regions (15–40°) in both hemispheres. Values in the tropics (15° N–15° S) were intermediate between those at the northern and southern temperate latitudes. Datasets available at doi:10.1594/PANGAEA.785501.
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Roy, T., F. Lombard, L. Bopp, and M. Gehlen. "Projected impacts of climate change and ocean acidification on the global biogeography of planktonic foraminifera." Biogeosciences Discussions 11, no. 6 (June 30, 2014): 10083–121. http://dx.doi.org/10.5194/bgd-11-10083-2014.
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Abstract. Planktonic foraminifera are a major contributor to the deep carbonate-flux and the planktonic biomass of the global ocean. Their microfossil deposits form one of the richest databases for reconstructing paleoenvironments, particularly through changes in their taxonomic and shell composition. Using an empirically-based foraminifer model that incorporates three known major physiological drivers of foraminifer biogeography – temperature, food and light – we investigate (i) the global redistribution of planktonic foraminifera under anthropogenic climate change, and (ii) the alteration of the carbonate chemistry of foraminifer habitat with ocean acidification. The present-day and future (2090–2100) 3-D distributions of foraminifera are simulated using temperature, plankton biomass, and light from an Earth system model forced with historical and a future (IPCC A2) high CO2 emission scenario. The broadscale patterns of present day foraminifer biogeography are well reproduced. Foraminifer abundance and diversity are projected to decrease in the tropics and subpolar regions and increase in the subtropics and around the poles. In the tropics, the geographical shifts are driven by temperature, while the vertical shifts are driven by both temperature and food availability. In the high-latitudes, vertical shifts are driven by food availability, while geographical shifts are driven by both food availability and temperature. Changes in the marine carbon cycle would be expected in response to (i) the large-scale rearrangements in foraminifer abundance, and (ii) the reduction of the carbonate concentration in the habitat range of planktonic foraminifers: from 10–30 μmol kg−1 in the polar/subpolar regions to 30–70 μmol kg−1 in the subtropical/tropical regions. High-latitude species are most vulnerable to anthropogenic change: their abundance and available habitat decrease and up to 10% of their habitat drops below the calcite saturation horizon.
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Mills, Claudia E. "A new hydrozoan, Geomackiea zephyrolata gen. nov., sp. nov. (Anthomedusae: Pandeidae), from inland marine waters of British Columbia and Washington State." Canadian Journal of Zoology 63, no. 9 (September 1, 1985): 2172–75. http://dx.doi.org/10.1139/z85-320.
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The hydromedusa Geomackiea zephyrolata gen. nov., sp. nov. is described and illustrated. It has been placed in the subfamily Protiarinae of the family Pandeidae on the basis of its stomach and gonad morphology and the four large perradial tentacles with conical basal bulbs. A new genus has been erected because the medusa is supplied with four broad interradial bulbs, each rimmed by up to eight closely packed solid tentaculae. A total of 29 specimens with bell heights of 0.9–3.5 mm have been collected in the plankton of Saanich Inlet, British Columbia, and Friday Harbor, Washington, between 1978 and 1981. Juvenile as well as adult specimens are described and the cnidome, gametes, seasonal and vertical distributions, and taxonomic affinities within the family Pandeidae are discussed.
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Njire, Jakica, Mirna Batistić, Vedrana Kovačević, Rade Garić, and Manuel Bensi. "Tintinnid Ciliate Communities in Pre- and Post-Winter Conditions in the Southern Adriatic Sea (NE Mediterranean)." Water 11, no. 11 (November 7, 2019): 2329. http://dx.doi.org/10.3390/w11112329.
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The Southern Adriatic Sea is a dynamic region under the influence of diverse physical forces that modify sea water properties as well as plankton dynamics, abundance, and distribution in an intricate way. The most pronounced being: winter vertical convection, lateral exchanges between coastal and open sea waters, and the ingression of water masses of different properties into the Adriatic. We investigated the distribution and abundance of tintinnid species in this dynamic environment in pre- and post-winter conditions in 2015/2016. A strong ingression of the saline Levantine Intermediate Water, supported by the cyclonic mode of the North Ionian Gyre in 2015 and 2016, in December was associated with a high diversity of oceanic species. An unusual spatial distribution of neritic-estuarine species Codonellopsis schabi was observed in deeper layers along the analyzed transect, which emphasizes the strong influence of physical processes on deep water biology in the South Adriatic. A shift of population toward greater depths (mesopelagic) and modification of deep sea community structure was recorded in April as a consequence of the winter convection-driven sinking of tintinnids. Our findings indicate that tintinnid abundance and composition is heavily influenced by physical conditions and they are good indicators of the impact of physical forces, including climate changes, on marine environment.
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Moreira, Fabiana T., Joseph Harari, and Augusto A. V. Flores. "Neustonic distribution of decapod planktonic stages and competence of brachyuran megalopae in coastal waters." Marine and Freshwater Research 58, no. 6 (2007): 519. http://dx.doi.org/10.1071/mf07002.
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Settlement rate may not reflect larval supply to coastal waters in different marine invertebrates and demersal fishes. The importance of near-shore oceanography and behaviour of late larval stages may be underestimated. The present study conducted neustonic sampling over station grids and along full-length transects at two embayments in south-eastern Brazil to (1) compare diurnal and nocturnal occurrence of most frequent decapod stages to assess their vertical movements, (2) describe the formation of larval patches and (3) measure competence of crab megalopae according to their distance to recruitment grounds. Several shrimp species apparently undergo a diel vertical migration, swimming crab megalopae showed no vertical movements and megalopae of the intertidal crab Pachygrapsus transversus revealed a reversed vertical migration. During the day, crab megalopae aggregated in convergence zones just below surface slicks. These larvae consisted of advanced, pre-moult stages, at both mid-bay and near-shore patches. Competence, measured as the time to metamorphosis in captivity, was similar between larval patches within each taxon. Yet, subtidal portunids moulted faster to juveniles than intertidal grapsids, possibly because they were closer to settlement grounds. Megalopae of Pachygrapsus from benthic collectors moulted faster than those from bay areas. These results suggest that alternative vertical migration patterns of late megalopae favour onshore transport, and actual competence takes place very close to suitable substrates, where larvae may remain for days before settlement. Lack of correlation between larval supply and settlement for Pachygrapsus suggests that biological processes, besides onshore transport, may play an important role in determining settlement success of coastal crabs.
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Le Gland, Guillaume, Sergio M. Vallina, S. Lan Smith, and Pedro Cermeño. "SPEAD 1.0 – Simulating Plankton Evolution with Adaptive Dynamics in a two-trait continuous fitness landscape applied to the Sargasso Sea." Geoscientific Model Development 14, no. 4 (April 13, 2021): 1949–85. http://dx.doi.org/10.5194/gmd-14-1949-2021.
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Abstract. Diversity plays a key role in the adaptive capacity of marine ecosystems to environmental changes. However, modelling the adaptive dynamics of phytoplankton traits remains challenging due to the competitive exclusion of sub-optimal phenotypes and the complexity of evolutionary processes leading to optimal phenotypes. Trait diffusion (TD) is a recently developed approach to sustain diversity in plankton models by introducing mutations, therefore allowing the adaptive evolution of functional traits to occur at ecological timescales. In this study, we present a model called Simulating Plankton Evolution with Adaptive Dynamics (SPEAD) that resolves the eco-evolutionary processes of a multi-trait plankton community. The SPEAD model can be used to evaluate plankton adaptation to environmental changes at different timescales or address ecological issues affected by adaptive evolution. Phytoplankton phenotypes in SPEAD are characterized by two traits, the nitrogen half-saturation constant and optimal temperature, which can mutate at each generation using the TD mechanism. SPEAD does not resolve the different phenotypes as discrete entities, instead computing six aggregate properties: total phytoplankton biomass, the mean value of each trait, trait variances, and the inter-trait covariance of a single population in a continuous trait space. Therefore, SPEAD resolves the dynamics of the population's continuous trait distribution by solving its statistical moments, wherein the variances of trait values represent the diversity of ecotypes. The ecological model is coupled to a vertically resolved (1D) physical environment, and therefore the adaptive dynamics of the simulated phytoplankton population are driven by seasonal variations in vertical mixing, nutrient concentration, water temperature, and solar irradiance. The simulated bulk properties are validated by observations from Bermuda Atlantic Time-series Studies (BATS) in the Sargasso Sea. We find that moderate mutation rates sustain trait diversity at decadal timescales and soften the almost total inter-trait correlation induced by the environment alone, without reducing the annual primary production or promoting permanently maladapted phenotypes, as occur with high mutation rates. As a way to evaluate the performance of the continuous trait approximation, we also compare the solutions of SPEAD to the solutions of a classical discrete entities approach, with both approaches including TD as a mechanism to sustain trait variance. We only find minor discrepancies between the continuous model SPEAD and the discrete model, with the computational cost of SPEAD being lower by 2 orders of magnitude. Therefore, SPEAD should be an ideal eco-evolutionary plankton model to be coupled to a general circulation model (GCM) of the global ocean.
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Massana, Ramon, Lance T. Taylor, Alison E. Murray, Ke Y. Wu, Wade H. Jeffrey, and Edward F. DeLong. "Vertical distribution and temporal variation of marine planktonic archaea in the Gerlache Strait, Antarctica, during early spring." Limnology and Oceanography 43, no. 4 (June 1998): 607–17. http://dx.doi.org/10.4319/lo.1998.43.4.0607.
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Ishitani, Yoshiyuki, and Kiyotaka Takishita. "Molecular evidence for wide vertical distribution of the marine planktonic protistLarcopyle buetschlii(Radiolaria) in a semi-enclosed marginal sea." Journal of Plankton Research 37, no. 5 (August 6, 2015): 851–56. http://dx.doi.org/10.1093/plankt/fbv065.
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Zakardjian, Bruno A., Jeffrey A. Runge, Stephane Plourde, and Yves Gratton. "A biophysical model of the interaction between vertical migration of crustacean zooplankton and circulation in the Lower St. Lawrence Estuary." Canadian Journal of Fisheries and Aquatic Sciences 56, no. 12 (December 1, 1999): 2420–32. http://dx.doi.org/10.1139/f99-095.
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As an essential step in modeling the influence of circulation on the population dynamics of marine planktonic copepods, we define a simple formulation of swimming behavior that can be used in both Eulerian and Lagrangian models. This formulation forces aggregation of the population toward a preferential depth and can be stage specific and time varying, thus allowing description of either diurnal or seasonal vertical migration. We use the formulation to examine the interaction between the circulation and vertical distribution in controlling horizontal distribution of the common planktonic copepod Calanus finmarchicus in the Lower St. Lawrence Estuary, Canada. We first introduce diel migration into a simple one-dimensional model and then into a model of residual two-dimensional circulation patterns representative of conditions encountered in the Lower St. Lawrence Estuary. Results from the latter indicate that interactions between circulation and stage-specific swimming behaviors are the main mechanisms for aggregation of planktonic crustaceans at the head of the Laurentian Channel and highlight the implications of flushing of the surface-dwelling young stages for the population dynamics of C. finmarchicus in the Lower St. Lawrence Estuary.
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Suzuki, T., and A. Taniguchi. "Standing crops and vertical distribution of four groups of marine planktonic ciliates in relation to phytoplankton chlorophyll a." Marine Biology 132, no. 3 (October 29, 1998): 375–82. http://dx.doi.org/10.1007/s002270050404.
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Nolan, Sean, Stephen M. Bollens, and Gretchen Rollwagen-Bollens. "Diverse taxa of zooplankton inhabit hypoxic waters during both day and night in a temperate eutrophic lake." Journal of Plankton Research 41, no. 4 (July 2019): 431–47. http://dx.doi.org/10.1093/plankt/fbz021.
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Abstract As the frequency and intensity of hypoxic events increase in both fresh and marine waters, understanding the ecological effects of hypoxia becomes more important. The extant literature reports varying effects of hypolimnetic hypoxia on the vertical distribution and diel vertical migration (DVM) of zooplankton, with some but not all taxa reported to avoid hypoxic waters. We studied the vertical distribution and DVM of diverse zooplankton taxa throughout three seasons over 2 years (2014 and 2015) in Lacamas Lake, WA, USA. We observed hypoxia (<2 mg L−1 dissolved oxygen) in the hypolimnion of Lacamas Lake during five of six sampling periods, with zooplankton populations often exhibiting ‘h-metric’ values (defined as the proportion of a zooplankton population residing within hypoxic waters) ranged from 0.14 to 1.00, with an overall mean of h = 0.66. Moreover, we observed a lack of DVM in most zooplankton taxa on most occasions. Our findings indicate both community-level and taxon-specific zooplankton tolerances to hypoxia, although the exact mechanisms at play remain to be fully elucidated. Nevertheless, the common residency in hypoxic waters and the lack of DVM by diverse zooplankton taxa that we observed likely have implications for food web dynamics in Lacamas Lake and other water bodies.
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Pahlow, Markus, Chia-Te Chien, Lionel A. Arteaga, and Andreas Oschlies. "Optimality-based non-Redfield plankton–ecosystem model (OPEM v1.1) in UVic-ESCM 2.9 – Part 1: Implementation and model behaviour." Geoscientific Model Development 13, no. 10 (October 2, 2020): 4663–90. http://dx.doi.org/10.5194/gmd-13-4663-2020.
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Abstract. Uncertainties in projections of marine biogeochemistry from Earth system models (ESMs) are associated to a large degree with the imperfect representation of the marine plankton ecosystem, in particular the physiology of primary and secondary producers. Here, we describe the implementation of an optimality-based plankton–ecosystem model (OPEM) version 1.1 with variable carbon : nitrogen : phosphorus (C:N:P) stoichiometry in the University of Victoria ESM (UVic; Eby et al., 2009; Weaver et al., 2001) and the behaviour of two calibrated reference configurations, which differ in the assumed temperature dependence of diazotrophs. Predicted tracer distributions of oxygen and dissolved inorganic nutrients are similar to those of an earlier fixed-stoichiometry formulation in UVic (Nickelsen et al., 2015). Compared to the classic fixed-stoichiometry UVic model, OPEM is closer to recent satellite-based estimates of net community production (NCP), despite overestimating net primary production (NPP), can better reproduce deep-ocean gradients in the NO3-:PO43- ratio and partially explains observed patterns of particulate C:N:P in the surface ocean. Allowing diazotrophs to grow (but not necessarily fix N2) at similar temperatures as other phytoplankton results in a better representation of surface Chl and NPP in the Arctic and Antarctic oceans. Deficiencies of our calibrated OPEM configurations may serve as a magnifying glass for shortcomings in global biogeochemical models and hence guide future model development. The overestimation of NPP at low latitudes indicates the need for improved representations of temperature effects on biotic processes, as well as phytoplankton community composition, which may be represented by locally varying parameters based on suitable trade-offs. The similarity in the overestimation of NPP and surface autotrophic particulate organic carbon (POC) could indicate deficiencies in the representation of top-down control or nutrient supply to the surface ocean. Discrepancies between observed and predicted vertical gradients in particulate C:N:P ratios suggest the need to include preferential P remineralisation, which could also benefit the representation of N2 fixation. While OPEM yields a much improved distribution of surface N* (NO3--16⋅PO43-+2.9 mmol m−3), it still fails to reproduce observed N* in the Arctic, possibly related to a misrepresentation of the phytoplankton community there and the lack of benthic denitrification in the model. Coexisting ordinary and diazotrophic phytoplankton can exert strong control on N* in our simulations, which questions the interpretation of N* as reflecting the balance of N2 fixation and denitrification.
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Rossi, V., C. López, E. Hernández-García, J. Sudre, V. Garçon, and Y. Morel. "Surface mixing and biological activity in the four Eastern Boundary Upwelling Systems." Nonlinear Processes in Geophysics 16, no. 4 (August 27, 2009): 557–68. http://dx.doi.org/10.5194/npg-16-557-2009.
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Abstract. Eastern Boundary Upwelling Systems (EBUS) are characterized by a high productivity of plankton associated with large commercial fisheries, thus playing key biological and socio-economical roles. Since they are populated by several physical oceanic structures such as filaments and eddies, which interact with the biological processes, it is a major challenge to study this sub- and mesoscale activity in connection with the chlorophyll distribution. The aim of this work is to make a comparative study of these four upwelling systems focussing on their surface stirring, using the Finite Size Lyapunov Exponents (FSLEs), and their biological activity, based on satellite data. First, the spatial distribution of horizontal mixing is analysed from time averages and from probability density functions of FSLEs, which allow us to divide each areas in two different subsystems. Then we studied the temporal variability of surface stirring focussing on the annual and seasonal cycle. We also proposed a ranking of the four EBUS based on the averaged mixing intensity. When investigating the links with chlorophyll concentration, the previous subsystems reveal distinct biological signatures. There is a global negative correlation between surface horizontal mixing and chlorophyll standing stocks over the four areas. To try to better understand this inverse relationship, we consider the vertical dimension by looking at the Ekman-transport and vertical velocities. We suggest the possibility of a changing response of the phytoplankton to sub/mesoscale turbulence, from a negative effect in the very productive coastal areas to a positive one in the open ocean. This study provides new insights for the understanding of the variable biological productivity in the ocean, which results from both dynamics of the marine ecosystem and of the 3-D turbulent medium.
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Maas, Amy E., Hannah Gossner, Maisie J. Smith, and Leocadio Blanco-Bercial. "Use of optical imaging datasets to assess biogeochemical contributions of the mesozooplankton." Journal of Plankton Research 43, no. 3 (May 2021): 475–91. http://dx.doi.org/10.1093/plankt/fbab037.
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Abstract The increasing use of image-based observing systems in marine ecosystems allows for more quantitative analysis of the ecological zonation of zooplankton. Developing methods that take advantage of these systems can provide an increasingly nuanced understanding of how morphometric characteristics (especially size) are related to distribution, abundance and ecosystem function via a wider application of allometric calculations of biogeochemical fluxes. Using MOCNESS sampling of zooplankton near the Bermuda Atlantic Time Series and a ZooSCAN/EcoTaxa pipeline, we apply a new taxonomically resolved biomass to biovolume dataset and a suite of R scripts that provide information about the relationships between zooplankter size, taxonomy, distribution, depth of migration, magnitude of migration and biogeochemical contributions (e.g. respiratory O2 consumption). The analysis pipeline provides a framework for quantitatively comparing and testing hypotheses about the distribution, migration patterns and biogeochemical impacts of mesozooplankton. Specifically, our code helps to visualize a size-based structure in the extent of vertical migration and allow for a quantification of the relative importance of non-migratory versus migratory organisms of various size classes. It additionally allows us to quantify the error associated with various methods of calculating active flux, with size-based analysis being the most important methodological choice, and taxonomic identification being the least.
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Llir�s, Marc, Frederic Gich, Anna Plasencia, Jean-Christophe Auguet, Fran�ois Darchambeau, Emilio O. Casamayor, Jean-Pierre Descy, and Carles Borrego. "Vertical Distribution of Ammonia-Oxidizing Crenarchaeota and Methanogens in the Epipelagic Waters of Lake Kivu (Rwanda-Democratic Republic of the Congo)." Applied and Environmental Microbiology 76, no. 20 (August 27, 2010): 6853–63. http://dx.doi.org/10.1128/aem.02864-09.
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ABSTRACT Four stratified basins in Lake Kivu (Rwanda-Democratic Republic of the Congo) were sampled in March 2007 to investigate the abundance, distribution, and potential biogeochemical role of planktonic archaea. We used fluorescence in situ hybridization with catalyzed-reported deposition microscopic counts (CARD-FISH), denaturing gradient gel electrophoresis (DGGE) fingerprinting, and quantitative PCR (qPCR) of signature genes for ammonia-oxidizing archaea (16S rRNA for marine Crenarchaeota group 1.1a [MCG1] and ammonia monooxygenase subunit A [amoA]). Abundance of archaea ranged from 1 to 4.5% of total DAPI (4′,6-diamidino-2-phenylindole) counts with maximal concentrations at the oxic-anoxic transition zone (∼50-m depth). Phylogenetic analysis of the archaeal planktonic community revealed a higher level of richness of crenarchaeal 16S rRNA gene sequences (21 of the 28 operational taxonomic units [OTUs] identified [75%]) over euryarchaeotal ones (7 OTUs). Sequences affiliated with the kingdom Euryarchaeota were mainly recovered from the anoxic water compartment and mostly grouped into methanogenic lineages (Methanosarcinales and Methanocellales). In turn, crenarchaeal phylotypes were recovered throughout the sampled epipelagic waters (0- to 100-m depth), with clear phylogenetic segregation along the transition from oxic to anoxic water masses. Thus, whereas in the anoxic hypolimnion crenarchaeotal OTUs were mainly assigned to the miscellaneous crenarchaeotic group, the OTUs from the oxic-anoxic transition and above belonged to Crenarchaeota groups 1.1a and 1.1b, two lineages containing most of the ammonia-oxidizing representatives known so far. The concomitant vertical distribution of both nitrite and nitrate maxima and the copy numbers of both MCG1 16S rRNA and amoA genes suggest the potential implication of Crenarchaeota in nitrification processes occurring in the epilimnetic waters of the lake.
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Szetey, A., DW Wright, F. Oppedal, and T. Dempster. "Salmon lice nauplii and copepodids display different vertical migration patterns in response to light." Aquaculture Environment Interactions 13 (May 6, 2021): 121–31. http://dx.doi.org/10.3354/aei00396.
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Light is a fundamental environmental cue which influences the migration of many marine organisms. For the salmon louse Lepeophtheirus salmonis, light is believed to drive the diel vertical migration behaviour of their planktonic larvae. Salmon lice are of critical importance to the salmonid industry due to the damage they cause to wild and farmed hosts. Salmon lice larvae have an eyespot and are positively phototactic, yet how light intensity alters their vertical distribution remains unclear. Here, we tested how light intensity (0, 0.5, 10 and 80 µmol m-2 s-1), dispersal duration (1, 4 and 12 h) and release point (surface or bottom) influenced the vertical migration of salmon lice nauplii and copepodids under controlled conditions in experimental columns. Overall, higher light intensity increased the proportion of nauplii that aggregated at the surface. Copepodid behaviour differed from that of nauplii, as they swam upwards in both light and fully dark conditions, and surface aggregations increased with dispersal duration. Results from the experiments did not support the existing view that light strongly influences the vertical position of copepodids in the water column. Combined with previous work, our results reveal that salmon lice larval stages display different vertical responses to light, temperature and salinity, which may be explained by the different strategies of nauplii (maximise survival and dispersal) and copepodids (maximise host-finding success). Our results have implications for salmon lice dispersal models, where responses of copepodids and nauplii to light are currently parametrised by the same equations. Implementing stage-specific behaviours towards light may improve the outputs of dispersal models.
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Fernández, Ana, Rocío Graña, Beatriz Mouriño-Carballido, Antonio Bode, Manuel Varela, J. Francisco Domínguez-Yanes, José Escánez, Demetrio de Armas, and Emilio Marañón. "Community N2 fixation and Trichodesmium spp. abundance along longitudinal gradients in the eastern subtropical North Atlantic." ICES Journal of Marine Science 70, no. 1 (August 21, 2012): 223–31. http://dx.doi.org/10.1093/icesjms/fss142.
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AbstractFernández, A., Graña, R., Mouriño-Carballido, B., Bode, A., Varela, M., Domínguez-Yanes, J. F., Escánez, J., de Armas, D., and Marañón, E. 2013. Community N2 fixation and Trichodesmium spp. abundance along longitudinal gradients in the eastern subtropical North Atlantic. – ICES Journal of Marine Science, 70:223–231. We have determined planktonic community N2 fixation, Trichodesmium abundance, the concentration and vertical diffusive flux of phosphate, and satellite-derived estimates of atmospheric concentration of dust along two longitudinal transects in the eastern subtropical North Atlantic during November 2007 and from April–May 2008. Trichodesmium abundance was particularly low (<3 trichome l−1) during the spring 2008 cruise, when low sea surface temperatures were recorded and vertical stratification was less marked. However, community N2 fixation was always measurable, albeit low compared with other regions of the tropical Atlantic. The average, vertically-integrated N2 fixation rate was 1.20 ± 0.48 µmol N m−2 d−1 in autumn 2007 and 8.31 ± 3.31 µmol N m−2 d−1 in spring 2008. The comparison of these rates of diazotrophy with the observed Trichodesmium abundances suggests that other, presumably unicellular, diazotrophs must have contributed significantly to community N2 fixation, at least during the spring 2008 cruise. Satellite data of atmospheric dust concentration suggested similar rates of atmospheric deposition during the two surveys. In contrast, vertical diffusive fluxes of phosphate were 5-fold higher in spring than in autumn (14.2 ± 12.1 µmol P m−2 d−1 and 2.8 ± 2.6 µmol P m−2 d−1, respectively), which may have stimulated N2 fixation. These findings agree with the growing view that N2 fixation is a more widespread process than the distribution of Trichodesmium alone may suggest. Our data also suggest a role for phosphorus supply in controlling the local variability of diazotrophic activity in a region subject to relatively high atmospheric inputs of iron.
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Vézina, Alain F. "Ecosystem modelling of the cycling of marine dimethylsulfide: a review of current approaches and of the potential for extrapolation to global scales." Canadian Journal of Fisheries and Aquatic Sciences 61, no. 5 (May 1, 2004): 845–56. http://dx.doi.org/10.1139/f04-025.
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There is rising interest from oceanic and atmospheric scientists in the potential role of dimethylsulphide (DMS) in regulating global climate. The increased availability of field observations of DMS and related compounds (DMS(P)) and of their transformation rates in the ocean has stimulated the development of ecosystem models of marine sulfur cycling. The models cover a wide range of complexity levels and spatial/temporal scales, from zero-dimensional local simulations spanning a few days to regional/global simulations driven by ocean general circulation models. The degree of complexity required to model DMS(P) dynamics, particularly the differentiation into phyto plankton species or groups, remains an important open question. First attempts to drive these models with vertically resolved turbulence models suggest interesting interactions between DMS(P) dynamics and fine-scale ocean mixing that can modify fluxes of DMS to the atmosphere. Recent models also bring into focus the strong affinities between the cycling of DMS(P) and that of dissolved organic carbon in the surface ocean. Formal parameter estimation techniques, which are increasingly used in ecosystem modelling of carbon and nitrogen dynamics, should play a stronger role in the development of DMS sulfur modelling. Extrapolation of DMS cycling and fluxes to the global scale presently relies largely on empirical approach. A semiempirical approach, based on a simple ecosystem model, is shown to reproduce gross features of the global distribution of DMS in the surface ocean. This shows promise for the continuing development of ecosystem models for global modelling of marine sulfur fluxes to the atmosphere.
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Selander, Erik, Sam T. Fredriksson, and Lars Arneborg. "Chemical Signaling in the Turbulent Ocean—Hide and Seek at the Kolmogorov Scale." Fluids 5, no. 2 (April 21, 2020): 54. http://dx.doi.org/10.3390/fluids5020054.
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Chemical cues and signals mediate resource acquisition, mate finding, and the assessment of predation risk in marine plankton. Here, we use the chemical properties of the first identified chemical cues from zooplankton together with in situ measurements of turbulent dissipation rates to calculate the effect of turbulence on the distribution of cues behind swimmers as well as steady state background concentrations in surrounding water. We further show that common zooplankton (copepods) appears to optimize mate finding by aggregating at the surface in calm conditions when turbulence do not prevent trail following. This near surface environment is characterized by anisotropic turbulence and we show, using direct numerical simulations, that chemical cues distribute more in the horizontal plane than vertically in these conditions. Zooplankton may consequently benefit from adopting specific search strategies near the surface as well as in strong stratification where similar flow fields develop. Steady state concentrations, where exudation is balanced by degradation develops in a time scale of ~5 h. We conclude that the trails behind millimeter-sized copepods can be detected in naturally occurring turbulence below the wind mixed surface layer or in the absence of strong wind. The trails, however, shorten dramatically at high turbulent dissipation rates, above ~10−3 cm2 s−3 (10−7 W kg−1)
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Countway, Peter D., and David A. Caron. "Abundance and Distribution of Ostreococcus sp. in the San Pedro Channel, California, as Revealed by Quantitative PCR." Applied and Environmental Microbiology 72, no. 4 (April 2006): 2496–506. http://dx.doi.org/10.1128/aem.72.4.2496-2506.2006.
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ABSTRACT Ostreococcus is a genus of widely distributed marine phytoplankton which are picoplanktonic in size (<2 μm) and capable of rapid growth. Although Ostreococcus has been detected around the world, little quantitative information exists on its contribution to planktonic communities. We designed and implemented a genus-specific TaqMan-based quantitative PCR (qPCR) assay to investigate the dynamics and ecology of Ostreococcus at the USC Microbial Observatory (eastern North Pacific). Samples were collected from 5 m and the deep chlorophyll maximum (DCM) between September 2000 and August 2002. Ostreococcus abundance at 5 m was generally <5.0 × 103 cells ml−1, with a maximum of 8.2 × 104 cells ml−1. Ostreococcus abundance was typically higher at the DCM, with a maximum of 3.2 × 105 cells ml−1. The vertical distribution of Ostreococcus was examined in March 2005 and compared to the distribution of phototrophic picoeukaryotes (PPE) measured by flow cytometry. The largest contribution to PPE abundance by Ostreococcus was ∼70% and occurred at 30 m, near the DCM. Despite its relatively low abundance, the depth-integrated standing stock of Ostreococcus in March 2005 was ∼30 mg C m−2. Our work provides a new technique for quantifying the abundance of Ostreococcus and demonstrates the seasonal dynamics of this genus and its contribution to picoeukaryote biomass at our coastal sampling station.
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Ward, Ben A., and Michael J. Follows. "Marine mixotrophy increases trophic transfer efficiency, mean organism size, and vertical carbon flux." Proceedings of the National Academy of Sciences 113, no. 11 (February 1, 2016): 2958–63. http://dx.doi.org/10.1073/pnas.1517118113.
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Mixotrophic plankton, which combine the uptake of inorganic resources and the ingestion of living prey, are ubiquitous in marine ecosystems, but their integrated biogeochemical impacts remain unclear. We address this issue by removing the strict distinction between phytoplankton and zooplankton from a global model of the marine plankton food web. This simplification allows the emergence of a realistic trophic network with increased fidelity to empirical estimates of plankton community structure and elemental stoichiometry, relative to a system in which autotrophy and heterotrophy are mutually exclusive. Mixotrophy enhances the transfer of biomass to larger sizes classes further up the food chain, leading to an approximately threefold increase in global mean organism size and an ∼35% increase in sinking carbon flux.
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Ruuska, M., and T. Hultamo. "Vertical distribution of plankton in Lake Pyhäselkä, Eastern Finland." SIL Proceedings, 1922-2010 29, no. 3 (March 2006): 1457–60. http://dx.doi.org/10.1080/03680770.2005.11902923.
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Onbé, T., and T. Ikeda. "Marine cladocerans in Toyama Bay, southern Japan Sea: seasonal occurrence and day-night vertical distributions." Journal of Plankton Research 17, no. 3 (1995): 595–609. http://dx.doi.org/10.1093/plankt/17.3.595.
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Zhou, M. "An objective interpolation method for spatiotemporal distribution of marine plankton." Marine Ecology Progress Series 174 (1998): 197–206. http://dx.doi.org/10.3354/meps174197.
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Li, Yan, Jiahong Guo, Xiaomin Guo, Zhiqiang Hu, and Yu Tian. "Plankton Detection with Adversarial Learning and a Densely Connected Deep Learning Model for Class Imbalanced Distribution." Journal of Marine Science and Engineering 9, no. 6 (June 8, 2021): 636. http://dx.doi.org/10.3390/jmse9060636.
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Detecting and classifying the plankton in situ to analyze the population diversity and abundance is fundamental for the understanding of marine planktonic ecosystem. However, the features of plankton are subtle, and the distribution of different plankton taxa is extremely imbalanced in the real marine environment, both of which limit the detection and classification performance of them while implementing the advanced recognition models, especially for the rare taxa. In this paper, a novel plankton detection strategy is proposed combining with a cycle-consistent adversarial network and a densely connected YOLOV3 model, which not only solves the class imbalanced distribution problem of plankton by augmenting data volume for the rare taxa but also reduces the loss of the features in the plankton detection neural network. The mAP of the proposed plankton detection strategy achieved 97.21% and 97.14%, respectively, under two experimental datasets with a difference in the number of rare taxa, which demonstrated the superior performance of plankton detection comparing with other state-of-the-art models. Especially for the rare taxa, the detection accuracy for each rare taxa is improved by about 4.02% on average under the two experimental datasets. Furthermore, the proposed strategy may have the potential to be deployed into an autonomous underwater vehicle for mobile plankton ecosystem observation.
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Mullin, Michael M., and Takashi Onbé. "Diel reproduction and vertical distributions of the marine cladocerans, Evadne tergestina and Penilia avirostris, in contrasting coastal environments." Journal of Plankton Research 14, no. 1 (1992): 41–59. http://dx.doi.org/10.1093/plankt/14.1.41.
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Drits, A. V., A. F. Pasternak, M. D. Kravchishina, E. G. Arashkevich, I. N. Sukhanova, and M. V. Flint. "Role of plankton in the vertical flux in the East Siberian sea shelf." Океанология 59, no. 5 (November 5, 2019): 746–54. http://dx.doi.org/10.31857/s0030-1574595746-754.
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Role of plankton in the vertical flux in the East Siberian Sea was studied in the 69 cruise of the RV Akademik Mstislav Keldysh in September 2017. Vertical fluxes were measured in sediment traps samples collected in the area of Indigirka river plume and in the marine shelf area. Mass vertical flux and particulate organic carbon flux varied from 80 to 530 mg/м2/d and from 16 to 49 mgС/м2/d, accordingly. Phytoplankton in sediment traps was dominated by cysts and spores of diatoms and dinoflagellates. Phytoplankton flux increased with depths from 0.220.33 to 1.21.3 мgС/м2/d. Fecal pellet fluxes (712 mgС/м2/d) was almost similar at two studied stations and did not change with depth. Zooplankton in the traps was dominated by houses of larvacean and carcasses of copepods Jashnovia tolli and Calanus glacialis Flux of zooplankton varied from 3 to 17 mgС/m2/d. The influence of the continental runoff reflected in a decrease of the proportion of planktonogenic components in the vertical flux of organic carbon. In the river plume area their total contribution to organic carbon flux did not exceed 30%; on the marine shelf it reached 80%.
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Ferek, R. J., R. B. Chatfield, and M. O. Andreae. "Vertical distribution of dimethylsulphide in the marine atmosphere." Nature 320, no. 6062 (April 1986): 514–16. http://dx.doi.org/10.1038/320514a0.
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Napp, JM, ER Brooks, FMH Reid, P. Matrai, and MM Mullin. "Vertical distribution of marine particles and grazers. I. Vertical distribution of food quality and quantity." Marine Ecology Progress Series 50 (1988): 45–58. http://dx.doi.org/10.3354/meps050045.
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Crawford, R. E., C. Hudon, and D. G. Parsons. "An Acoustic Study of Shrimp (Pandalus montagui) Distribution near Resolution Island (Eastern Hudson Strait)." Canadian Journal of Fisheries and Aquatic Sciences 49, no. 5 (May 1, 1992): 842–56. http://dx.doi.org/10.1139/f92-095.
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Echo integration, a multistage plankton sampler (BIONESS), and a bottom trawl were used to examine the horizontal and vertical distribution of shrimp (Pandalus montagui) near Resolution Island in eastern Hudson Strait. Shrimp were concentrated in two locations within the study area and they maintained this pattern of horizontal distribution for at least 7 d. Acoustic observations revealed a scale of horizontal patchiness that was obscured by the "homogenization effect" of sampling by bottom trawl and plankton net. The shrimp underwent a nocturnal vertical migration with other zooplankton to > 200 m from the bottom and a subsequent downward migration during early daylight hours. This diel migration resulted in reduced availability of shrimp to the bottom trawl at night. Timing of the migrations varied, possibly as a result of interaction with oceanographic processes.
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Santi, I., P. Kasapidis, S. Psarra, G. Assimakopoulou, A. Pavlidou, M. Protopapa, A. Tsiola, C. Zeri, and P. Pitta. "Composition and distribution patterns of eukaryotic microbial plankton in the ultra-oligotrophic Eastern Mediterranean Sea." Aquatic Microbial Ecology 84 (June 4, 2020): 155–73. http://dx.doi.org/10.3354/ame01933.
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Marine microbial eukaryotes play crucial roles in water-column ecosystems; however, there are regional gaps in the investigation of natural microbial eukaryote communities, and uncertainties concerning their distribution persevere. This study combined 18S rRNA metabarcoding, biomass measurements and statistical analyses of multiple environmental variables to examine the distribution of planktonic microbial eukaryotes at different sites and water layers in the ultra-oligotrophic Eastern Mediterranean Sea (Western Levantine Basin). Our results showed that microbial eukaryotic communities were structured by depth. In surface waters, different sites shared high percentages of molecular operational taxonomic units (MOTUs), but this was not the case for deep-sea communities (≥1000 m). Plankton biomass was significantly different among sites, implying that communities of a similar composition may not support the same activity or population size. The deep-sea communities showed high percentages of unassigned MOTUs, highlighting the sparsity of the existing information on deep-sea plankton eukaryotes. Water temperature and dissolved organic matter significantly affected community distribution. Micro-eukaryotic distribution was additionally affected by the nitrogen to phosphorus ratio and viral abundance, while nano- and pico-communities were affected by zooplankton. The present study explores microbial plankton eukaryotes in their natural oligotrophic environment and highlights that, even within restricted oceanic areas, marine plankton may follow distribution patterns that are largely controlled by environmental variables.
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Macías, Diego, Ángel Rodríguez-Santana, Eduardo Ramírez-Romero, Miguel Bruno, Josep L. Pelegrí, Pablo Sangrà, Borja Aguiar-González, and Carlos M. García. "Turbulence as a driver for vertical plankton distribution in the subsurface upper ocean." Scientia Marina 77, no. 4 (October 21, 2013): 541–49. http://dx.doi.org/10.3989/scimar.03854.03a.
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Steenbergen, C. L. M., H. J. Korthals, A. L. Baker, and C. J. Watras. "Microscale vertical distribution of algal and bacterial plankton in Lake Vechten (The Netherlands)." FEMS Microbiology Letters 62, no. 4 (June 1989): 209–19. http://dx.doi.org/10.1111/j.1574-6968.1989.tb03695.x.
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Randelhoff, Achim, and Arild Sundfjord. "Short commentary on marine productivity at Arctic shelf breaks: upwelling, advection and vertical mixing." Ocean Science 14, no. 2 (April 18, 2018): 293–300. http://dx.doi.org/10.5194/os-14-293-2018.
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Abstract. The future of Arctic marine ecosystems has received increasing attention in recent years as the extent of the sea ice cover is dwindling. Although the Pacific and Atlantic inflows both import huge quantities of nutrients and plankton, they feed into the Arctic Ocean in quite diverse regions. The strongly stratified Pacific sector has a historically heavy ice cover, a shallow shelf and dominant upwelling-favourable winds, while the Atlantic sector is weakly stratified, with a dynamic ice edge and a complex bathymetry. We argue that shelf break upwelling is likely not a universal but rather a regional, albeit recurring, feature of “the new Arctic”. It is the regional oceanography that decides its importance through a range of diverse factors such as stratification, bathymetry and wind forcing. Teasing apart their individual contributions in different regions can only be achieved by spatially resolved time series and dedicated modelling efforts. The Northern Barents Sea shelf is an example of a region where shelf break upwelling likely does not play a dominant role, in contrast to the shallower shelves north of Alaska where ample evidence for its importance has already accumulated. Still, other factors can contribute to marked future increases in biological productivity along the Arctic shelf break. A warming inflow of nutrient-rich Atlantic Water feeds plankton at the same time as it melts the sea ice, permitting increased photosynthesis. Concurrent changes in sea ice cover and zooplankton communities advected with the boundary currents make for a complex mosaic of regulating factors that do not allow for Arctic-wide generalizations.