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Rodríguez-Pérez MY, Sánchez-Velasco L, Ruvalcaba-Aroche ED, Beier E, Tenorio-Fernandez L. δ 13C and δ 15N zooplankton isoscapes as trace of water masses and mesoscale activity in the Pacific Tropical-Subtropical Convergence off Mexico during June 2010. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 909:168497. [PMID: 37977367 DOI: 10.1016/j.scitotenv.2023.168497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Revised: 11/08/2023] [Accepted: 11/09/2023] [Indexed: 11/19/2023]
Abstract
This research analyzes for the first time in the Pacific Tropical-Subtropical Convergence off Mexico during June 2010 the relationships among the δ13C and δ15N signal distribution in the bulk zooplankton, water masses, and mesoscale structures. The environmental analysis showed that the California Current Water (CCW) and Transitional Water (TrW) converge where the 22 °C isotherm and 34.6 g kg-1 isohaline were observed (22°N). Two cyclonic eddies were detected: one in CCW at 24°N about 70 km in diameter, the other one located in TrW at 21°N with 150 km in diameter. A cluster analysis defined three zooplankton isoscapes with significant differences. Isoscape 1, immerses in CCW - the lowest δ13C (-22.37 ± 0.89 ‰) and δ15N (9.89 ± 1.32 ‰) - showed temperature (19.86 ± 1.97 °C), salinity (34.08 ± 0.37 g kg-1) values, the deepest thermocline (77.93 ± 25.51 m) and oxygen minimum zone (164.78 ± 44.96 m). The CCW was relatively oligotrophic without important mesoscale features in the sampled time within the sampled area. Isoscape 2, a cyclonic eddy in CCW - relatively enriched zooplankton δ13C values (-16.78 ± 1.95 ‰) due to the entry of enriched coastal biota- reflected in high chlorophyll a and subsequently assimilated into zooplankton tissues. Isoscape 3, a cyclonic eddy immerses in TrW - the highest δ15N (13.14 ± 1.60 ‰), salinity (34.76 ± 0.19 g kg-1) and temperature (19.90 ± 2.27 °C) values and shallowest thermocline (32.27 ± 18.63 m), and oxygen minimum zone (66.82 ± 37.68 m) in depth. Likely, this 15N-enriched recycled nitrate was pumped from the deoxygenated subsurface to the surface, reflected in the zooplankton bulks. The results showed that the isotopic signals in bulk zooplankton may be a good water mass and mesoscale activity tracer.
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Affiliation(s)
- M Y Rodríguez-Pérez
- Instituto Politécnico Nacional- Centro Interdisciplinario de Ciencias Marinas, Departamento de Oceanología, Av. Instituto Politécnico Nacional s/n, Col. Playa Palo de Santa Rita, C.P. 23096 La Paz, Baja California Sur, Mexico.
| | - L Sánchez-Velasco
- Instituto Politécnico Nacional- Centro Interdisciplinario de Ciencias Marinas, Departamento de Oceanología, Av. Instituto Politécnico Nacional s/n, Col. Playa Palo de Santa Rita, C.P. 23096 La Paz, Baja California Sur, Mexico.
| | - E D Ruvalcaba-Aroche
- Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE)-Unidad La Paz. Laboratorio de Macroecología Marina, C.P. 23050 La Paz, Baja California Sur, Mexico
| | - E Beier
- Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE)-Unidad La Paz. Laboratorio de Macroecología Marina, C.P. 23050 La Paz, Baja California Sur, Mexico
| | - L Tenorio-Fernandez
- Instituto Politécnico Nacional- Centro Interdisciplinario de Ciencias Marinas, Departamento de Oceanología, Av. Instituto Politécnico Nacional s/n, Col. Playa Palo de Santa Rita, C.P. 23096 La Paz, Baja California Sur, Mexico; CONAHCyT, Consejo Nacional de Humanidades Ciencia y Tecnología, Av. Insurgentes Sur 1582, Col. Crédito Constructor, Alcaldía Benito Juárez, C.P. 03940 Mexico City, Mexico
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Gleich SJ, Hu SK, Krinos AI, Caron DA. Protistan community composition and metabolism in the North Pacific Subtropical Gyre: Influences of mesoscale eddies and depth. Environ Microbiol 2024; 26:e16556. [PMID: 38081167 DOI: 10.1111/1462-2920.16556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 11/27/2023] [Indexed: 01/30/2024]
Abstract
Marine protists and their metabolic activities are intricately tied to the cycling of nutrients and the flow of energy through microbial food webs. Physiochemical changes in the environment, such as those that result from mesoscale eddies, may impact protistan communities, but the effects that such changes have on protists are poorly known. A metatranscriptomic study was conducted to investigate how eddies affected protists at adjacent cyclonic and anticyclonic eddy sites in the oligotrophic ocean at four depths from 25 to 250 m. Eddy polarity impacted protists at all depths sampled, although the effects of eddy polarity were secondary to the impact of depth across the depth range. Eddy-induced vertical shifts in the water column yielded differences in the cyclonic and anticyclonic eddy protistan communities, and these differences were the most pronounced at and just below the deep chlorophyll maximum. An analysis of transcripts associated with protistan nutritional physiology at 150 m revealed that cyclonic eddies may support a more heterotrophic community, while anticyclonic eddies promote a more phototrophic community. The results of this study indicate that eddies alter the metabolism of protists particularly in the lower euphotic zone and may therefore impact carbon export from the euphotic zone.
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Affiliation(s)
- Samantha J Gleich
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
| | - Sarah K Hu
- Department of Oceanography, Texas A&M University, College Station, Texas, USA
| | - Arianna I Krinos
- MIT-WHOI Joint Program in Oceanography and Applied Ocean Science and Engineering, Cambridge and Woods Hole, Cambridge, Massachusetts, USA
- Department of Biology, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
- Department of Earth, Atmospheric, and Planetary Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - David A Caron
- Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
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Setta SP, Lerch S, Jenkins BD, Dyhrman ST, Rynearson TA. Oligotrophic waters of the Northwest Atlantic support taxonomically diverse diatom communities that are distinct from coastal waters. JOURNAL OF PHYCOLOGY 2023; 59:1202-1216. [PMID: 37737069 DOI: 10.1111/jpy.13388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 07/23/2023] [Accepted: 08/09/2023] [Indexed: 09/23/2023]
Abstract
Diatoms are important components of the marine food web and one of the most species-rich groups of phytoplankton. The diversity and composition of diatoms in eutrophic nearshore habitats have been well documented due to the outsized influence of diatoms on coastal ecosystem functioning. In contrast, patterns of both diatom diversity and community composition in offshore oligotrophic regions where diatom biomass is low have been poorly resolved. To compare the diatom diversity and community composition in oligotrophic and eutrophic waters, diatom communities were sampled along a 1,250 km transect from the oligotrophic Sargasso Sea to the coastal waters of the northeast US shelf. Diatom community composition was determined by amplifying and sequencing the 18S rDNA V4 region. Of the 301 amplicon sequence variants (ASVs) identified along the transect, the majority (70%) were sampled exclusively from oligotrophic waters of the Gulf Stream and Sargasso Sea and included the genera Bacteriastrum, Haslea, Hemiaulus, Pseudo-nitzschia, and Nitzschia. Diatom ASV richness did not vary along the transect, indicating that the oligotrophic Sargasso Sea and Gulf Stream are occupied by a diverse diatom community. Although ASV richness was similar between oligotrophic and coastal waters, diatom community composition in these regions differed significantly and was correlated with temperature and phosphate, two environmental variables known to influence diatom metabolism and geographic distribution. In sum, oligotrophic waters of the western North Atlantic harbor diverse diatom assemblages that are distinct from coastal regions, and these open ocean diatoms warrant additional study, as they may play critical roles in oligotrophic ecosystems.
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Affiliation(s)
- Samantha P Setta
- Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island, USA
| | - Sarah Lerch
- College of the Environment and Life Sciences, University of Rhode Island, Kingston, Rhode Island, USA
| | - Bethany D Jenkins
- Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island, USA
- College of the Environment and Life Sciences, University of Rhode Island, Kingston, Rhode Island, USA
| | - Sonya T Dyhrman
- Department of Earth and Environmental Sciences, Columbia University, Palisades, New York, USA
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, New York, USA
| | - Tatiana A Rynearson
- Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island, USA
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Gronniger JL, Gray PC, Niebergall AK, Johnson ZI, Hunt DE. A Gulf Stream frontal eddy harbors a distinct microbiome compared to adjacent waters. PLoS One 2023; 18:e0293334. [PMID: 37943816 PMCID: PMC10635494 DOI: 10.1371/journal.pone.0293334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 10/10/2023] [Indexed: 11/12/2023] Open
Abstract
Mesoscale oceanographic features, including eddies, have the potential to alter productivity and other biogeochemical rates in the ocean. Here, we examine the microbiome of a cyclonic, Gulf Stream frontal eddy, with a distinct origin and environmental parameters compared to surrounding waters, in order to better understand the processes dominating microbial community assembly in the dynamic coastal ocean. Our microbiome-based approach identified the eddy as distinct from the surround Gulf Stream waters. The eddy-associated microbial community occupied a larger area than identified by temperature and salinity alone, increasing the predicted extent of eddy-associated biogeochemical processes. While the eddy formed on the continental shelf, after two weeks both environmental parameters and microbiome composition of the eddy were most similar to the Gulf Stream, suggesting the effect of environmental filtering on community assembly or physical mixing with adjacent Gulf Stream waters. In spite of the potential for eddy-driven upwelling to introduce nutrients and stimulate primary production, eddy surface waters exhibit lower chlorophyll a along with a distinct and less even microbial community, compared to the Gulf Stream. At the population level, the eddy microbiome exhibited differences among the cyanobacteria (e.g. lower Trichodesmium and higher Prochlorococcus) and in the heterotrophic alpha Proteobacteria (e.g. lower relative abundances of specific SAR11 phylotypes) versus the Gulf Stream. However, better delineation of the relative roles of processes driving eddy community assembly will likely require following the eddy and surrounding waters since inception. Additionally, sampling throughout the water column could better clarify the contribution of these mesoscale features to primary production and carbon export in the oceans.
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Affiliation(s)
| | - Patrick C. Gray
- Marine Laboratory, Duke University, Beaufort, NC, United States of America
| | | | - Zackary I. Johnson
- Marine Laboratory, Duke University, Beaufort, NC, United States of America
- Biology and Civil & Environmental Engineering, Duke University, Durham, NC, United States of America
| | - Dana E. Hunt
- Marine Laboratory, Duke University, Beaufort, NC, United States of America
- Biology and Civil & Environmental Engineering, Duke University, Durham, NC, United States of America
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Sun FL, Wang YS, Wu ML, Sun CC, Jiang ZY, Cheng H, Fei J. Bacterial community variations in the South China Sea driven by different chemical conditions. ECOTOXICOLOGY (LONDON, ENGLAND) 2021; 30:1808-1815. [PMID: 34269924 DOI: 10.1007/s10646-021-02455-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/03/2021] [Indexed: 06/13/2023]
Abstract
In this study, Illumina MiSeq sequencing of the 16 S rRNA gene was used to describe the bacterial communities in the South China Sea (SCS) during the southwest monsoon period. We targeted different regions in the SCS and showed that bacterial community was driven by the effects of the river, upwelling, and mesoscale eddy through changing the environmental factors (salinity, temperature, and nutrients). Distinct bacterial communities were observed among different chemical conditions, especially between the estuary and the open sea. The abundance of Burkholderiales, Frankiales, Flavobacteriales, and Rhodobacterales dominated the estuary and its adjacent waters. Bacteria in cyclonic eddy were dominated by Methylophilales and Pseudomonadales, whereas Prochlorococcus, SAR11 clade, and Oceanospirillales had relatively high abundance in the anticyclonic eddy. Overall, the abundance of specific phylotypes significantly varied among samples with different chemical conditions. Chemical conditions probably act as a driver that shapes and controls the diversity of bacteria in the SCS. This study suggests that the interaction between microbial and environmental conditions needs to be further considered to fully understand the diversity and function of marine microbes.
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Affiliation(s)
- Fu-Lin Sun
- State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- Daya Bay Marine Biology Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Shenzhen, 518121, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - You-Shao Wang
- State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.
- Daya Bay Marine Biology Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Shenzhen, 518121, China.
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 510301, China.
| | - Mei-Lin Wu
- State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Cui-Ci Sun
- State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- Daya Bay Marine Biology Research Station, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Shenzhen, 518121, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Zhao-Yu Jiang
- State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Hao Cheng
- State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Jiao Fei
- State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China
- Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 510301, China
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6
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Harke MJ, Frischkorn KR, Hennon GMM, Haley ST, Barone B, Karl DM, Dyhrman ST. Microbial community transcriptional patterns vary in response to mesoscale forcing in the North Pacific Subtropical Gyre. Environ Microbiol 2021; 23:4807-4822. [PMID: 34309154 DOI: 10.1111/1462-2920.15677] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Accepted: 07/18/2021] [Indexed: 11/30/2022]
Abstract
The physical and biological dynamics that influence phytoplankton communities in the oligotrophic ocean are complex, changing across broad temporal and spatial scales. Eukaryotic phytoplankton (e.g., diatoms), despite their relatively low abundance in oligotrophic waters, are responsible for a large component of the organic matter flux to the ocean interior. Mesoscale eddies can impact both microbial community structure and function, enhancing primary production and carbon export, but the mechanisms that underpin these dynamics are still poorly understood. Here, mesoscale eddy influences on the taxonomic diversity and expressed functional profiles of surface communities of microeukaryotes and particle-associated heterotrophic bacteria from the North Pacific Subtropical Gyre were assessed over 2 years (spring 2016 and summer 2017). The taxonomic diversity of the microeukaryotes significantly differed by eddy polarity (cyclonic versus anticyclonic) and between sampling seasons/years and was significantly correlated with the taxonomic diversity of particle-associated heterotrophic bacteria. The expressed functional profile of these taxonomically distinct microeukaryotes varied consistently as a function of eddy polarity, with cyclones having a different expression pattern than anticyclones, and between sampling seasons/years. These data suggest that mesoscale forcing, and associated changes in biogeochemistry, could drive specific physiological responses in the resident microeukaryote community, independent of species composition.
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Affiliation(s)
- Matthew J Harke
- Lamont-Doherty Earth Observatory, Biology and Paleo Environment, Columbia University, Palisades, NY, USA.,Gloucester Marine Genomics Institute, Gloucester, MA, USA
| | - Kyle R Frischkorn
- Lamont-Doherty Earth Observatory, Biology and Paleo Environment, Columbia University, Palisades, NY, USA
| | - Gwenn M M Hennon
- Lamont-Doherty Earth Observatory, Biology and Paleo Environment, Columbia University, Palisades, NY, USA.,College of Fisheries and Ocean Sciences, University of Alaska, Fairbanks, AK, USA
| | - Sheean T Haley
- Lamont-Doherty Earth Observatory, Biology and Paleo Environment, Columbia University, Palisades, NY, USA
| | - Benedetto Barone
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawaii at Manoa, Honolulu, HI, USA.,Department of Oceanography, University of Hawaii at Manoa, Honolulu, HI, USA
| | - David M Karl
- Daniel K. Inouye Center for Microbial Oceanography: Research and Education, University of Hawaii at Manoa, Honolulu, HI, USA.,Department of Oceanography, University of Hawaii at Manoa, Honolulu, HI, USA
| | - Sonya T Dyhrman
- Lamont-Doherty Earth Observatory, Biology and Paleo Environment, Columbia University, Palisades, NY, USA.,Department of Earth and Environmental Sciences, Columbia University, New York, NY, USA
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7
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Anatomy of a Cyclonic Eddy in the Kuroshio Extension Based on High-Resolution Observations. ATMOSPHERE 2019. [DOI: 10.3390/atmos10090553] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mesoscale eddies are common in the ocean and their surface characteristics have been well revealed based on altimetric observations. Comparatively, the knowledge of the three-dimensional (3D) structure of mesoscale eddies is scarce, especially in the open ocean. In the present study, high-resolution field observations of a cyclonic eddy in the Kuroshio Extension have been carried out and the anatomy of the observed eddy is conducted. The temperature anomaly exhibits a vertical monopole cone structure with a maximum of −7.3 °C located in the main thermocline. The salinity anomaly shows a vertical dipole structure with a fresh anomaly in the main thermocline and a saline anomaly in the North Pacific Intermediate Water (NPIW). The cyclonic flow displays an equivalent barotropic structure. The mixed layer is deep in the center of the eddy and thin in the periphery. The seasonal thermocline is intensified and the permanent thermocline is upward domed by 350 m. The subtropical mode water (STMW) straddled between the seasonal and permanent thermoclines weakens and dissipates in the eddy center. The salinity of NPIW distributed along the isopycnals shows no significant difference inside and outside the eddy. The geostrophic relation is approximately set up in the eddy. The nonlinearity—defined as the ratio between the rotational speed to the translational speed—is 12.5 and decreases with depth. The eddy-wind interaction is examined by high resolution satellite observations. The results show that the cold eddy induces wind stress aloft with positive divergence and negative curl. The wind induced upwelling process is responsible for the formation of the horizontal monopole pattern of salinity, while the horizontal transport results in the horizontal dipole structure of temperature in the mixed layer.
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Abstract
Lava discharge to the ocean from volcano Kīlauea, Hawai'i, triggers phytoplankton blooms
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Affiliation(s)
- Hugh Ducklow
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA.
| | - Terry Plank
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA
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Mesoscale eddies release pelagic sharks from thermal constraints to foraging in the ocean twilight zone. Proc Natl Acad Sci U S A 2019; 116:17187-17192. [PMID: 31387979 PMCID: PMC6717292 DOI: 10.1073/pnas.1903067116] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
New dynamic approaches to managing marine fisheries promise more effective management in a changing climate. However, they require detailed knowledge of the links between oceanographic features and marine megafauna. Here, we demonstrate that satellite tracking of animal movements, combined with ocean remote sensing and numerical models, can provide this critical information for the most exploited pelagic shark in the Atlantic Ocean. We find that this predator dives deep in warm, swirling water masses called eddies that have traditionally been considered ocean “deserts.” Sharks use these warm features as a conduit to forage in the ocean twilight zone, a region of the deep ocean that contains the largest fish biomass on Earth, highlighting the importance of these deep ocean prey resources. Mesoscale eddies are critical components of the ocean’s “internal weather” system. Mixing and stirring by eddies exerts significant control on biogeochemical fluxes in the open ocean, and eddies may trap distinctive plankton communities that remain coherent for months and can be transported hundreds to thousands of kilometers. Debate regarding how and why predators use fronts and eddies, for example as a migratory cue, enhanced forage opportunities, or preferred thermal habitat, has been ongoing since the 1950s. The influence of eddies on the behavior of large pelagic fishes, however, remains largely unexplored. Here, we reconstruct movements of a pelagic predator, the blue shark (Prionace glauca), in the Gulf Stream region using electronic tags, earth-observing satellites, and data-assimilating ocean forecasting models. Based on >2,000 tracking days and nearly 500,000 high-resolution time series measurements collected by 15 instrumented individuals, we show that blue sharks seek out the interiors of anticyclonic eddies where they dive deep while foraging. Our observations counter the existing paradigm that anticyclonic eddies are unproductive ocean “deserts” and suggest anomalously warm temperatures in these features connect surface-oriented predators to the most abundant fish community on the planet in the mesopelagic. These results also shed light on the ecosystem services provided by mesopelagic prey. Careful consideration will be needed before biomass extraction from the ocean twilight zone to avoid interrupting a key link between planktonic production and top predators. Moreover, robust associations between targeted fish species and oceanographic features increase the prospects for effective dynamic ocean management.
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Becker JW, Hogle SL, Rosendo K, Chisholm SW. Co-culture and biogeography of Prochlorococcus and SAR11. THE ISME JOURNAL 2019; 13:1506-1519. [PMID: 30742057 PMCID: PMC6775983 DOI: 10.1038/s41396-019-0365-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 01/03/2019] [Accepted: 01/18/2019] [Indexed: 01/07/2023]
Abstract
Prochlorococcus and SAR11 are among the smallest and most abundant organisms on Earth. With a combined global population of about 2.7 × 1028 cells, they numerically dominate bacterioplankton communities in oligotrophic ocean gyres and yet they have never been grown together in vitro. Here we describe co-cultures of Prochlorococcus and SAR11 isolates representing both high- and low-light adapted clades. We examined: (1) the influence of Prochlorococcus on the growth of SAR11 and vice-versa, (2) whether Prochlorococcus can meet specific nutrient requirements of SAR11, and (3) how co-culture dynamics vary when Prochlorococcus is grown with SAR11 compared with sympatric copiotrophic bacteria. SAR11 grew 15-70% faster in co-culture with Prochlorococcus, while the growth of the latter was unaffected. When Prochlorococcus populations entered stationary phase, this commensal relationship rapidly became amensal, as SAR11 abundances decreased dramatically. In parallel experiments with copiotrophic bacteria; however, the heterotrophic partner increased in abundance as Prochlorococcus densities leveled off. The presence of Prochlorococcus was able to meet SAR11's central requirement for organic carbon, but not reduced sulfur. Prochlorococcus strain MIT9313, but not MED4, could meet the unique glycine requirement of SAR11, which could be due to the production and release of glycine betaine by MIT9313, as supported by comparative genomic evidence. Our findings also suggest, but do not confirm, that Prochlorococcus MIT9313 may compete with SAR11 for the uptake of 3-dimethylsulfoniopropionate (DMSP). To give our results an ecological context, we assessed the relative contribution of Prochlorococcus and SAR11 genome equivalents to those of identifiable bacteria and archaea in over 800 marine metagenomes. At many locations, more than half of the identifiable genome equivalents in the euphotic zone belonged to Prochlorococcus and SAR11 - highlighting the biogeochemical potential of these two groups.
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Affiliation(s)
- Jamie W Becker
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Department of Biology, Haverford College, Haverford, PA, USA.
| | - Shane L Hogle
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Kali Rosendo
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Sallie W Chisholm
- Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
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11
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El Aouni A, Daoudi K, Yahia H, Minaoui K, Benazzouz A. Surface mixing and biological activity in the North-West African upwelling. CHAOS (WOODBURY, N.Y.) 2019; 29:011104. [PMID: 30709139 DOI: 10.1063/1.5067253] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 12/24/2018] [Indexed: 06/09/2023]
Abstract
Near-shore water along the North-West African margin is one of the world's major upwelling regions. It is associated with physical structures of oceanic fronts which influence the biological productivity. The study of these coherent structures in connection with chlorophyll concentration data is of fundamental importance for understanding the spatial distributions of the plankton. In this work, we study the horizontal stirring and mixing in different upwelling areas using Lagrangian coherent structures (LCSs). These LCSs are calculated using the recent geodesic theory of LCSs. We use these LCSs to study the link between the chlorophyll fronts concentrations and surface mixing, based on 10 years of satellite data. These LCSs move with the flow as material lines, thus the horizontal mixing is calculated from the intersection of these LCSs with the finite time Lyapunov exponent maps. We compare our results with those of a recent study conducted over the same area, but based on finite size Lyapunov exponents (FSLEs), whose output is a plot of scalar distributions. We discuss the differences between FSLE and geodesic theory of LCS. The latter yields analytical solutions of LCSs, while FSLEs can only provide LCSs for sharp enough ridges of nearly constant height.
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Affiliation(s)
- Anass El Aouni
- Geostat Team, INRIA Bordeaux Sud-Ouest, 33400 Talence, France
| | - Khalid Daoudi
- Geostat Team, INRIA Bordeaux Sud-Ouest, 33400 Talence, France
| | - Hussein Yahia
- Geostat Team, INRIA Bordeaux Sud-Ouest, 33400 Talence, France
| | - Khalid Minaoui
- University Mohammed V, Faculty of Sciences, LRIT, 10106 Rabat, Morocco
| | - Aïssa Benazzouz
- The Higher Institute of Maritime Studies, 20000 Casablanca, Morocco
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12
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Chang YLK, Miyazawa Y, Béguer-Pon M, Han YS, Ohashi K, Sheng J. Physical and biological roles of mesoscale eddies in Japanese eel larvae dispersal in the western North Pacific Ocean. Sci Rep 2018; 8:5013. [PMID: 29567996 PMCID: PMC5864879 DOI: 10.1038/s41598-018-23392-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 03/12/2018] [Indexed: 11/09/2022] Open
Abstract
The physical and biological roles of mesoscale eddies in Japanese eel larvae dispersal are investigated using a three-dimensional (3D) particle-tracking method, with a focus on the Subtropical Counter Current eddies of the western North Pacific Ocean. Virtual eel larvae (v-larvae) movements depends on the 3D ocean currents and active swimming behavior, including vertical swimming (diel vertical migration), horizontal directional swimming toward settlement habitat, and horizontal swimming toward available food. V-larvae are able to remain in eddies passively due to mesoscale eddy nonlinearity and/or actively due to attraction to rich food supplies. Thus, both physical trapping and biological attraction to food contribute to the retention of v-larvae in eddies. Physical trapping dominates the retention of v-larvae whose swimming speeds are slower than the eddy propagation speed, whereas biological food attraction prevails in the retention of v-larvae swimming faster than eddy propagation. Food availability differs between warm (anti-cyclonic) and cold (cyclonic) eddies, with the latter providing a richer food supply. Fish larvae that are retained for longer durations in cold eddies (shorter durations in warm eddies) are able to obtain more food and potentially grow faster, which enhances survival rates.
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Affiliation(s)
- Yu-Lin K Chang
- Application Laboratory, Japan Agency for Marine-Earth Science and Technology, Yokohama, 236-0001, Japan.
| | - Yasumasa Miyazawa
- Application Laboratory, Japan Agency for Marine-Earth Science and Technology, Yokohama, 236-0001, Japan
| | - Mélanie Béguer-Pon
- Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Yu-San Han
- Institute of Fisheries Science, National Taiwan University, Taipei, 106, Taiwan
| | - Kyoko Ohashi
- Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Jinyu Sheng
- Department of Oceanography, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
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13
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Goldberg SJ, Nelson CE, Viviani DA, Shulse CN, Church MJ. Cascading influence of inorganic nitrogen sources on DOM production, composition, lability and microbial community structure in the open ocean. Environ Microbiol 2017; 19:3450-3464. [PMID: 28618153 DOI: 10.1111/1462-2920.13825] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 05/26/2017] [Accepted: 05/29/2017] [Indexed: 12/22/2022]
Abstract
Nitrogen frequently limits oceanic photosynthesis and the availability of inorganic nitrogen sources in the surface oceans is shifting with global change. We evaluated the potential for abrupt increases in inorganic N sources to induce cascading effects on dissolved organic matter (DOM) and microbial communities in the surface ocean. We collected water from 5 m depth in the central North Pacific and amended duplicate 20 liter polycarbonate carboys with nitrate or ammonium, tracking planktonic carbon fixation, DOM production, DOM composition and microbial community structure responses over 1 week relative to controls. Both nitrogen sources stimulated bulk phytoplankton, bacterial and DOM production and enriched Synechococcus and Flavobacteriaceae; ammonium enriched for oligotrophic Actinobacteria OM1 and Gammaproteobacteria KI89A clades while nitrate enriched Gammaproteobacteria SAR86, SAR92 and OM60 clades. DOM resulting from both N enrichments was more labile and stimulated growth of copiotrophic Gammaproteobacteria (Alteromonadaceae and Oceanospirillaceae) and Alphaproteobacteria (Rhodobacteraceae and Hyphomonadaceae) in weeklong dark incubations relative to controls. Our study illustrates how nitrogen pulses may have direct and cascading effects on DOM composition and microbial community dynamics in the open ocean.
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Affiliation(s)
- S J Goldberg
- Center for Microbial Oceanography: Research and Education, Department of Oceanography, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, 1950 East West Road, Honolulu, HI 96822, USA
| | - C E Nelson
- Center for Microbial Oceanography: Research and Education, Department of Oceanography and Sea Grant College Program, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, 1950 East West Road, Honolulu, HI 96822, USA
| | - D A Viviani
- Center for Microbial Oceanography: Research and Education, Department of Oceanography, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, 1950 East West Road, Honolulu, HI 96822, USA
| | - C N Shulse
- Center for Microbial Oceanography: Research and Education, Department of Oceanography, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, 1950 East West Road, Honolulu, HI 96822, USA
| | - M J Church
- Center for Microbial Oceanography: Research and Education, Department of Oceanography, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, 1950 East West Road, Honolulu, HI 96822, USA
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14
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Gaube P, Barceló C, McGillicuddy DJ, Domingo A, Miller P, Giffoni B, Marcovaldi N, Swimmer Y. The use of mesoscale eddies by juvenile loggerhead sea turtles (Caretta caretta) in the southwestern Atlantic. PLoS One 2017; 12:e0172839. [PMID: 28249020 PMCID: PMC5383008 DOI: 10.1371/journal.pone.0172839] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 02/10/2017] [Indexed: 11/18/2022] Open
Abstract
Marine animals, such as turtles, seabirds and pelagic fishes, are observed to travel and congregate around eddies in the open ocean. Mesoscale eddies, large swirling ocean vortices with radius scales of approximately 50–100 km, provide environmental variability that can structure these populations. In this study, we investigate the use of mesoscale eddies by 24 individual juvenile loggerhead sea turtles (Caretta caretta) in the Brazil-Malvinas Confluence region. The influence of eddies on turtles is assessed by collocating the turtle trajectories to the tracks of mesoscale eddies identified in maps of sea level anomaly. Juvenile loggerhead sea turtles are significantly more likely to be located in the interiors of anticyclones in this region. The distribution of surface drifters in eddy interiors reveals no significant association with the interiors of cyclones or anticyclones, suggesting higher prevalence of turtles in anticyclones is a result of their behavior. In the southern portion of the Brazil-Malvinas Confluence region, turtle swimming speed is significantly slower in the interiors of anticyclones, when compared to the periphery, suggesting that these turtles are possibly feeding on prey items associated with anomalously low near-surface chlorophyll concentrations observed in those features.
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Affiliation(s)
- Peter Gaube
- Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America
- * E-mail:
| | - Caren Barceló
- College of Earth, Ocean and Atmospheric Sciences, Oregon State University, Corvallis, Oregon, United States of America
| | - Dennis J. McGillicuddy
- Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America
| | - Andrés Domingo
- Dirección Nacional de Recursos Acuáticos, Montevideo, Uruguay
| | - Philip Miller
- Centro de Investigación y Conservación Marina (CICMAR), El Pinar, Canelones, Uruguay
| | - Bruno Giffoni
- Projecto TAMAR, Fundação Pró Tamar / ICMBio, Salvador, Bahia, Brazil
| | - Neca Marcovaldi
- Projecto TAMAR, Fundação Pró Tamar / ICMBio, Salvador, Bahia, Brazil
| | - Yonat Swimmer
- NOAA Fisheries, Long Beach, California, United States of America
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15
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Mesoscale ocean fronts enhance carbon export due to gravitational sinking and subduction. Proc Natl Acad Sci U S A 2017; 114:1252-1257. [PMID: 28115723 DOI: 10.1073/pnas.1609435114] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Enhanced vertical carbon transport (gravitational sinking and subduction) at mesoscale ocean fronts may explain the demonstrated imbalance of new production and sinking particle export in coastal upwelling ecosystems. Based on flux assessments from 238U:234Th disequilibrium and sediment traps, we found 2 to 3 times higher rates of gravitational particle export near a deep-water front (305 mg C⋅m-2⋅d-1) compared with adjacent water or to mean (nonfrontal) regional conditions. Elevated particle flux at the front was mechanistically linked to Fe-stressed diatoms and high mesozooplankton fecal pellet production. Using a data assimilative regional ocean model fit to measured conditions, we estimate that an additional ∼225 mg C⋅m-2⋅d-1 was exported as subduction of particle-rich water at the front, highlighting a transport mechanism that is not captured by sediment traps and is poorly quantified by most models and in situ measurements. Mesoscale fronts may be responsible for over a quarter of total organic carbon sequestration in the California Current and other coastal upwelling ecosystems.
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16
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Caron DA, Alexander H, Allen AE, Archibald JM, Armbrust EV, Bachy C, Bell CJ, Bharti A, Dyhrman ST, Guida SM, Heidelberg KB, Kaye JZ, Metzner J, Smith SR, Worden AZ. Probing the evolution, ecology and physiology of marine protists using transcriptomics. Nat Rev Microbiol 2016; 15:6-20. [DOI: 10.1038/nrmicro.2016.160] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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17
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Adhikari PL, Maiti K, Bosu S, Jones PR. (234)Th as a tracer of vertical transport of polycyclic aromatic hydrocarbons in the northern Gulf of Mexico. MARINE POLLUTION BULLETIN 2016; 107:179-187. [PMID: 27090884 DOI: 10.1016/j.marpolbul.2016.04.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Revised: 03/04/2016] [Accepted: 04/02/2016] [Indexed: 06/05/2023]
Abstract
Particle-mediated vertical flux of polycyclic aromatic hydrocarbons (PAHs) plays an important role in their removal from upper oceans and sets a limit on the amount delivered to the deep-sea sediments. In this study, we applied a one-dimensional steady-state (234)Th scavenging model to estimate vertical flux of PAHs in the northern Gulf of Mexico and compared them with sediment trap based flux estimates. The (234)Th-based ∑PAH43 fluxes were 6.7±1.0μgm(-2)d(-1) and 3.7±0.6μgm(-2)d(-1) while sediment trap-based fluxes were 4.0±0.6μgm(-2)d(-1) and 4.5±0.7μgm(-2)d(-1) at 150m and 250m, respectively. Alkylated homologues contributed to 80% of the total PAH fluxes which is in contrary to other regions where combustion derived parent PAHs dominate the fluxes. The results indicate that the (238)U-(234)Th disequilibria can be an effective tracer of particulate PAH fluxes in upper mesopelagic zones and can provide flux estimates with high spatial coverage needed to quantify their long term fate and transport in the marine systems.
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Affiliation(s)
- Puspa L Adhikari
- Department of Oceanography and Coastal Sciences, Louisiana State University, 1143 ECE Building, Baton Rouge, LA 70803, United States; Department of Environmental Sciences, Louisiana State University, 1257 ECE Building, Baton Rouge, LA 70803, United States.
| | - Kanchan Maiti
- Department of Oceanography and Coastal Sciences, Louisiana State University, 1143 ECE Building, Baton Rouge, LA 70803, United States
| | - Somiddho Bosu
- Department of Oceanography and Coastal Sciences, Louisiana State University, 1143 ECE Building, Baton Rouge, LA 70803, United States
| | - Patrick R Jones
- Department of Oceanography and Coastal Sciences, Louisiana State University, 1143 ECE Building, Baton Rouge, LA 70803, United States
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18
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Wang L, Huang B, Chiang KP, Liu X, Chen B, Xie Y, Xu Y, Hu J, Dai M. Physical-Biological Coupling in the Western South China Sea: The Response of Phytoplankton Community to a Mesoscale Cyclonic Eddy. PLoS One 2016; 11:e0153735. [PMID: 27088991 PMCID: PMC4835056 DOI: 10.1371/journal.pone.0153735] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Accepted: 04/04/2016] [Indexed: 11/22/2022] Open
Abstract
It is widely recognized that the mesoscale eddies play an important part in the biogeochemical cycle in ocean ecosystem, especially in the oligotrophic tropical zones. So here a heterogeneous cyclonic eddy in its flourishing stage was detected using remote sensing and in situ biogeochemical observation in the western South China Sea (SCS) in early September, 2007. The high-performance liquid chromatography method was used to identify the photosynthetic pigments. And the CHEMical TAXonomy (CHEMTAX) was applied to calculate the contribution of nine phytoplankton groups to the total chlorophyll a (TChl a) biomass. The deep chlorophyll a maximum layer (DCML) was raised to form a dome structure in the eddy center while there was no distinct enhancement for TChl a biomass. The integrated TChl a concentration in the upper 100 m water column was also constant from the eddy center to the surrounding water outside the eddy. However the TChl a biomass in the surface layer (at 5 m) in the eddy center was promoted 2.6-fold compared to the biomass outside the eddy (p < 0.001). Thus, the slight enhancement of TChl a biomass of euphotic zone integration within the eddy was mainly from the phytoplankton in the upper mixed zone rather than the DCML. The phytoplankton community was primarily contributed by diatoms, prasinophytes, and Synechococcus at the DCML within the eddy, while less was contributed by haptophytes_8 and Prochlorococcus. The TChl a biomass for most of the phytoplankton groups increased at the surface layer in the eddy center under the effect of nutrient pumping. The doming isopycnal within the eddy supplied nutrients gently into the upper mixing layer, and there was remarkable enhancement in phytoplankton biomass at the surface layer with 10.5% TChl a biomass of water column in eddy center and 3.7% at reference stations. So the slight increasing in the water column integrated phytoplankton biomass might be attributed to the stimulated phytoplankton biomass at the surface layer.
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Affiliation(s)
- Lei Wang
- Key Laboratory of the Coastal and Wetland Ecosystems, the Ministry of Education, Xiamen University, Xiamen, China
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
| | - Bangqin Huang
- Key Laboratory of the Coastal and Wetland Ecosystems, the Ministry of Education, Xiamen University, Xiamen, China
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
- * E-mail:
| | - Kuo-Ping Chiang
- Institute of Marine Environmental Chemistry and Ecology, National Taiwan Ocean University, Keelung, Taiwan
| | - Xin Liu
- Key Laboratory of the Coastal and Wetland Ecosystems, the Ministry of Education, Xiamen University, Xiamen, China
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
| | - Bingzhang Chen
- Key Laboratory of the Coastal and Wetland Ecosystems, the Ministry of Education, Xiamen University, Xiamen, China
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
| | - Yuyuan Xie
- Key Laboratory of the Coastal and Wetland Ecosystems, the Ministry of Education, Xiamen University, Xiamen, China
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
| | - Yanping Xu
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
| | - Jianyu Hu
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
| | - Minhan Dai
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
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19
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Krause JW, Stukel MR, Taylor AG, Taniguchi DAA, De Verneil A, Landry MR. Net biogenic silica production and the contribution of diatoms to new production and organic matter export in the Costa Rica Dome ecosystem. JOURNAL OF PLANKTON RESEARCH 2016; 38:216-229. [PMID: 27275026 PMCID: PMC4889982 DOI: 10.1093/plankt/fbv077] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 08/21/2015] [Indexed: 05/25/2023]
Abstract
We determined the net rate of biogenic silica (bSiO2) production and estimated the diatom contribution to new production and organic matter export in the Costa Rica Dome during summer 2010. The shallow thermocline significantly reduces bSiO2 dissolution rates below the mixed layer, leading to significant enhancement of bSiO2 relative to organic matter (silicate-pump condition). This may explain why deep export of bSiO2 in this region is elevated by an order of magnitude relative to comparable systems. Diatom carbon, relative to autotrophic carbon, was low (<3%); however, the contribution of diatoms to new production averaged 3 and 13% using independent approaches. The 4-old discrepancy between methods may be explained by a low average C:Si ratio (∼1.4) for the net produced diatom C relative to the net produced bSiO2. We speculate that this low production ratio is not the result of reduced C, but may arise from a significant contribution of non-diatom silicifying organisms to bSiO2 production. The contribution of diatoms to organic matter export was minor (5.7%). These results, and those of the broader project, suggest substantial food-web transformation of diatom organic matter in the euphotic zone, which creates enriched bSiO2 relative to organic matter within the exported material.
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Affiliation(s)
- Jeffrey W. Krause
- Dauphin Island Sea Lab, 101 Bienville BLVD, Dauphin Island, AL 36528, USA
- University of South Alabama, Life Sciences Building Room 25, Mobile, AL 36688, USA
| | - Michael R. Stukel
- Florida State University, P.O. Box 3064520, Tallahassee, FL 32306-4520, USA
| | - Andrew G. Taylor
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
| | - Darcy A. A. Taniguchi
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Building 54-1511A, Cambridge, MA 02142, USA
| | - Alain De Verneil
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
| | - Michael R. Landry
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
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20
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Functional group-specific traits drive phytoplankton dynamics in the oligotrophic ocean. Proc Natl Acad Sci U S A 2015; 112:E5972-9. [PMID: 26460011 DOI: 10.1073/pnas.1518165112] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
A diverse microbial assemblage in the ocean is responsible for nearly half of global primary production. It has been hypothesized and experimentally demonstrated that nutrient loading can stimulate blooms of large eukaryotic phytoplankton in oligotrophic systems. Although central to balancing biogeochemical models, knowledge of the metabolic traits that govern the dynamics of these bloom-forming phytoplankton is limited. We used eukaryotic metatranscriptomic techniques to identify the metabolic basis of functional group-specific traits that may drive the shift between net heterotrophy and autotrophy in the oligotrophic ocean. Replicated blooms were simulated by deep seawater (DSW) addition to mimic nutrient loading in the North Pacific Subtropical Gyre, and the transcriptional responses of phytoplankton functional groups were assayed. Responses of the diatom, haptophyte, and dinoflagellate functional groups in simulated blooms were unique, with diatoms and haptophytes significantly (95% confidence) shifting their quantitative metabolic fingerprint from the in situ condition, whereas dinoflagellates showed little response. Significantly differentially abundant genes identified the importance of colimitation by nutrients, metals, and vitamins in eukaryotic phytoplankton metabolism and bloom formation in this system. The variable transcript allocation ratio, used to quantify transcript reallocation following DSW amendment, differed for diatoms and haptophytes, reflecting the long-standing paradigm of phytoplankton r- and K-type growth strategies. Although the underlying metabolic potential of the large eukaryotic phytoplankton was consistently present, the lack of a bloom during the study period suggests a crucial dependence on physical and biogeochemical forcing, which are susceptible to alteration with changing climate.
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21
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Williams AK, McInnes AS, Rooker JR, Quigg A. Changes in Microbial Plankton Assemblages Induced by Mesoscale Oceanographic Features in the Northern Gulf of Mexico. PLoS One 2015; 10:e0138230. [PMID: 26375709 PMCID: PMC4574113 DOI: 10.1371/journal.pone.0138230] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 08/27/2015] [Indexed: 11/27/2022] Open
Abstract
Mesoscale circulation generated by the Loop Current in the Northern Gulf of Mexico (NGOM) delivers growth-limiting nutrients to the microbial plankton of the euphotic zone. Consequences of physicochemically driven community shifts on higher order consumers and subsequent impacts on the biological carbon pump remain poorly understood. This study evaluates microbial plankton <10 μm abundance and community structure across both cyclonic and anti-cyclonic circulation features in the NGOM using flow cytometry (SYBR Green I and autofluorescence parameters). Non-parametric multivariate hierarchical cluster analyses indicated that significant spatial variability in community structure exists such that stations that clustered together were defined as having a specific ‘microbial signature’ (i.e. statistically homogeneous community structure profiles based on relative abundance of microbial groups). Salinity and a combination of sea surface height anomaly and sea surface temperature were determined by distance based linear modeling to be abiotic predictor variables significantly correlated to changes in microbial signatures. Correlations between increased microbial abundance and availability of nitrogen suggest nitrogen-limitation of microbial plankton in this open ocean area. Regions of combined coastal water entrainment and mesoscale convergence corresponded to increased heterotrophic prokaryote abundance relative to autotrophic plankton. The results provide an initial assessment of how mesoscale circulation potentially influences microbial plankton abundance and community structure in the NGOM.
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Affiliation(s)
- Alicia K. Williams
- Department of Oceanography, Texas A&M University, College Station, Texas, United States of America
- * E-mail:
| | - Allison S. McInnes
- Department of Oceanography, Texas A&M University, College Station, Texas, United States of America
- Climate Change Cluster, University of Technology, Sydney, Australia
| | - Jay R. Rooker
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, Texas, United States of America
- Department of Wildlife and Fisheries, Texas A&M University, College Station, Texas, United States of America
| | - Antonietta Quigg
- Department of Oceanography, Texas A&M University, College Station, Texas, United States of America
- Department of Marine Biology, Texas A&M University at Galveston, Galveston, Texas, United States of America
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22
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McGillicuddy DJ. Mechanisms of Physical-Biological-Biogeochemical Interaction at the Oceanic Mesoscale. ANNUAL REVIEW OF MARINE SCIENCE 2015; 8:125-159. [PMID: 26359818 DOI: 10.1146/annurev-marine-010814-015606] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Mesoscale phenomena are ubiquitous and highly energetic features of ocean circulation. Their influence on biological and biogeochemical processes varies widely, stemming not only from advective transport but also from the generation of variations in the environment that affect biological and chemical rates. The ephemeral nature of mesoscale features in the ocean makes it difficult to elucidate the attendant mechanisms of physical-biological-biogeochemical interaction, necessitating the use of multidisciplinary approaches involving in situ observations, remote sensing, and modeling. All three aspects are woven through this review in an attempt to synthesize current understanding of the topic, with particular emphasis on novel developments in recent years.
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Affiliation(s)
- Dennis J McGillicuddy
- Department of Applied Ocean Physics and Engineering, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543;
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23
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Yang W, Chen M, Zheng M, He Z, Zhang X, Qiu Y, Xu W, Ma L, Lin Z, Hu W, Zeng J. Influence of a Decaying Cyclonic Eddy on Biogenic Silica and Particulate Organic Carbon in the Tropical South China Sea Based on 234Th-238U Disequilibrium. PLoS One 2015; 10:e0136948. [PMID: 26317555 PMCID: PMC4552670 DOI: 10.1371/journal.pone.0136948] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 08/10/2015] [Indexed: 11/18/2022] Open
Abstract
Eddies play a critical role in regulating the biological pump by pumping new nutrients to the euphotic zone. However, the effects of cyclonic eddies on particle export are not well understood. Here, biogenic silica (BSi) and particulate organic carbon (POC) exports were examined inside and outside a decaying cyclonic eddy using 234Th-238U disequilibria in the tropical South China Sea. For the eddy and outside stations, the average concentrations of BSi in the euphotic zone were 0.17±0.09 μmol L-1 (mean±sd, n = 20) and 0.21±0.06 μmol L-1 (n = 34). The POC concentrations were 1.42±0.56 μmol L-1 (n = 34) and 1.30±0.46 μmol L-1 (n = 51). Both BSi and POC abundances did not show change at the 95% confidence level. Based on the 234Th-238U model, BSi export fluxes in the eddy averaged 0.18±0.15 mmol Si m-2 d-1, which was comparable with the 0.40±0.20 mmol Si m-2 d-1 outside the eddy. Similarly, the average POC export fluxes were 1.5±1.4 mmol C m-2 d-1 and 1.9±1.3 mmol C m-2 d-1 for the eddy and outside stations. From these results we concluded that cyclonic eddies in their decaying phase have little effect on the abundance and export of biogenic particles.
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Affiliation(s)
- Weifeng Yang
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
- * E-mail:
| | - Min Chen
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Minfang Zheng
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Zhigang He
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Xinxing Zhang
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Yusheng Qiu
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Wangbin Xu
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Lili Ma
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Zhiyu Lin
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Wangjiang Hu
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Jian Zeng
- College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
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24
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Shih YY, Hung CC, Gong GC, Chung WC, Wang YH, Lee IH, Chen KS, Ho CY. Enhanced Particulate Organic Carbon Export at Eddy Edges in the Oligotrophic Western North Pacific Ocean. PLoS One 2015; 10:e0131538. [PMID: 26171611 PMCID: PMC4501708 DOI: 10.1371/journal.pone.0131538] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 06/03/2015] [Indexed: 11/18/2022] Open
Abstract
Mesoscale eddies in the subtropical oligotrophic ocean are ubiquitous and play an important role in nutrient supply and oceanic primary production. However, it is still unclear whether these mesoscale eddies can efficiently transfer CO2 from the atmosphere to deep waters via biological pump because of the sampling difficulty due to their transient nature. In 2007, particulate organic carbon (POC) fluxes, measured below the euphotic zone at the edge of warm eddy were 136-194 mg-C m-2 d-1 which was greatly elevated over that (POC flux = 26-35 mg-C m-2 d-1) determined in the nutrient-depleted oligotrophic waters in the Western North Pacific (WNP). In 2010, higher POC fluxes (83-115 mg-C m-2 d-1) were also observed at the boundary of mesoscale eddies in the WNP. The enhanced POC flux at the edge of eddies was mainly attributed to both large denuded diatom frustules and zooplankton fecal pellets based on scanning electron microscopy (SEM) examination. The result suggests that mesoscale eddies in the oligotrophic waters in the subtropical WNP can efficiently increase the oceanic carbon export flux and the eddy edge is a crucial conduit in carbon sequestration to deep waters.
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Affiliation(s)
- Yung-Yen Shih
- Department of Oceanography, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan
| | - Chin-Chang Hung
- Department of Oceanography, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan
- * E-mail:
| | - Gwo-Ching Gong
- Institute of Marine Environmental Chemistry and Ecology, National Taiwan Ocean University, Keelung, 20224, Taiwan
| | - Wan-Chen Chung
- Institute of Marine Environmental Chemistry and Ecology, National Taiwan Ocean University, Keelung, 20224, Taiwan
| | - Yu-Huai Wang
- Department of Oceanography, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan
| | - I-Huan Lee
- Department of Oceanography, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan
| | - Kuo-Shu Chen
- Department of Oceanography, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan
| | - Chuang-Yi Ho
- Department of Oceanography, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan
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Alonso-González IJ, Arístegui J, Lee C, Sanchez-Vidal A, Calafat A, Fabrés J, Sangrá P, Mason E. Carbon dynamics within cyclonic eddies: insights from a biomarker study. PLoS One 2014; 8:e82447. [PMID: 24386098 PMCID: PMC3875410 DOI: 10.1371/journal.pone.0082447] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 11/01/2013] [Indexed: 11/19/2022] Open
Abstract
It is generally assumed that episodic nutrient pulses by cyclonic eddies into surface waters support a significant fraction of the primary production in subtropical low-nutrient environments in the northern hemisphere. However, contradictory results related to the influence of eddies on particulate organic carbon (POC) export have been reported. As a step toward understanding the complex mechanisms that control export of material within eddies, we present here results from a sediment trap mooring deployed within the path of cyclonic eddies generated near the Canary Islands over a 1.5-year period. We find that, during summer and autumn (when surface stratification is stronger, eddies are more intense, and a relative enrichment in CaCO3 forming organisms occurs), POC export to the deep ocean was 2-4 times higher than observed for the rest of the year. On the contrary, during winter and spring (when mixing is strongest and the seasonal phytoplankton bloom occurs), no significant enhancement of POC export associated with eddies was observed. Our biomarker results suggest that a large fraction of the material exported from surface waters during the late-winter bloom is either recycled in the mesopelagic zone or bypassed by migrant zooplankton to the deep scattering layer, where it would disaggregate to smaller particles or be excreted as dissolved organic carbon. Cyclonic eddies, however, would enhance carbon export below 1000 m depth during the summer stratification period, when eddies are more intense and frequent, highlighting the important role of eddies and their different biological communities on the regional carbon cycle.
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Affiliation(s)
- Iván J. Alonso-González
- Instituto de Oceanografía y Cambio Global (IOCAG), Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
- Spanish Bank of Algae (BEA), Telde, Spain
- * E-mail:
| | - Javier Arístegui
- Instituto de Oceanografía y Cambio Global (IOCAG), Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Cindy Lee
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, New York, United States of America
| | - Anna Sanchez-Vidal
- GRC Geociències Marines, Facultat de Geologia, Universitat de Barcelona, Barcelona, Spain
| | - Antoni Calafat
- GRC Geociències Marines, Facultat de Geologia, Universitat de Barcelona, Barcelona, Spain
| | - Joan Fabrés
- UNEP Shelf Programme Facility, UNEP/GRID-Arendal, Arendal, Norway
| | - Pablo Sangrá
- Instituto de Oceanografía y Cambio Global (IOCAG), Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, Spain
| | - Evan Mason
- Grup d'Oceanografia Fisica, Institut de Ciències del Mar, CMIMA-CSIC, Barcelona, Spain
- Mediterranean Institute for Advanced Studies (IMEDEA), Esporles, Spain
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Koester JA, Swanson WJ, Armbrust EV. Positive selection within a diatom species acts on putative protein interactions and transcriptional regulation. Mol Biol Evol 2012; 30:422-34. [PMID: 23097498 DOI: 10.1093/molbev/mss242] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Diatoms are the most species-rich group of microalgae, and their contribution to marine primary production is important on a global scale. Diatoms can form dense blooms through rapid asexual reproduction; mutations acquired and propagated during blooms likely provide the genetic, and thus phenotypic, variability upon which natural selection may act. Positive selection was tested using genome and transcriptome-wide pair-wise comparisons of homologs in three genera of diatoms (Pseudo-nitzschia, Ditylum, and Thalassiosira) that represent decreasing phylogenetic distances. The signal of positive selection was greatest between two strains of Thalassiosira pseudonana. Further testing among seven strains of T. pseudonana yielded 809 candidate genes of positive selection, which are 7% of the protein-coding genes. Orphan genes and genes encoding protein-binding domains and transcriptional regulators were enriched within the set of positively selected genes relative to the genome as a whole. Positively selected genes were linked to the potential selective pressures of nutrient limitation and sea surface temperature based on analysis of gene expression profiles and identification of positively selected genes in subsets of strains from locations with similar environmental conditions. The identification of positively selected genes presents an opportunity to test new hypotheses in natural populations and the laboratory that integrate selected genotypes in T. pseudonana with their associated phenotypes and selective forces.
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27
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Paduan JD, Washburn L. High-frequency radar observations of ocean surface currents. ANNUAL REVIEW OF MARINE SCIENCE 2012; 5:115-136. [PMID: 22809196 DOI: 10.1146/annurev-marine-121211-172315] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
This article reviews the discovery, development, and use of high-frequency (HF) radio wave backscatter in oceanography. HF radars, as the instruments are commonly called, remotely measure ocean surface currents by exploiting a Bragg resonant backscatter phenomenon. Electromagnetic waves in the HF band (3-30 MHz) have wavelengths that are commensurate with wind-driven gravity waves on the ocean surface; the ocean waves whose wavelengths are exactly half as long as those of the broadcast radio waves are responsible for the resonant backscatter. Networks of HF radar systems are capable of mapping surface currents hourly out to ranges approaching 200 km with a horizontal resolution of a few kilometers. Such information has many uses, including search and rescue support and oil-spill mitigation in real time and larval population connectivity assessment when viewed over many years. Today, HF radar networks form the backbone of many ocean observing systems, and the data are assimilated into ocean circulation models.
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Affiliation(s)
- Jeffrey D Paduan
- Department of Oceanography, Naval Postgraduate School, Monterey, CA 93943, USA.
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28
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Abstract
Mesoscale eddies stimulate biological production in the ocean, but knowledge of energy transfers to higher trophic levels within eddies remains fragmented and not quantified. Increasing the knowledge base is constrained by the inability of traditional sampling methods to adequately sample biological processes at the spatio-temporal scales at which they occur. By combining satellite and acoustic observations over spatial scales of 10 s of km horizontally and 100 s of m vertically, supported by hydrographical and biological sampling we show that anticyclonic eddies shape distribution and density of marine life from the surface to bathyal depths. Fish feed along density structures of eddies, demonstrating that eddies catalyze energy transfer across trophic levels. Eddies create attractive pelagic habitats, analogous to oases in the desert, for higher trophic level aquatic organisms through enhanced 3-D motion that accumulates and redistributes biomass, contributing to overall bioproduction in the ocean. Integrating multidisciplinary observation methodologies promoted a new understanding of biophysical interaction in mesoscale eddies. Our findings emphasize the impact of eddies on the patchiness of biomass in the sea and demonstrate that they provide rich feeding habitat for higher trophic marine life.
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Brzezinski MA, Washburn L. Phytoplankton primary productivity in the Santa Barbara Channel: Effects of wind-driven upwelling and mesoscale eddies. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011jc007397] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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30
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Calil PHR, Doney SC, Yumimoto K, Eguchi K, Takemura T. Episodic upwelling and dust deposition as bloom triggers in low-nutrient, low-chlorophyll regions. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010jc006704] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Zhang Y, Jiao N, Sun Z, Hu A, Zheng Q. Phylogenetic diversity of bacterial communities in South China Sea mesoscale cyclonic eddy perturbations. Res Microbiol 2011; 162:320-9. [DOI: 10.1016/j.resmic.2010.12.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2010] [Accepted: 11/10/2010] [Indexed: 12/20/2022]
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d’Ovidio F, De Monte S, Alvain S, Dandonneau Y, Lévy M. Fluid dynamical niches of phytoplankton types. Proc Natl Acad Sci U S A 2010; 107:18366-70. [PMID: 20974927 PMCID: PMC2972977 DOI: 10.1073/pnas.1004620107] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The biogeochemical role of phytoplanktonic organisms strongly varies from one plankton type to another, and their relative abundance and distribution have fundamental consequences at the global and climatological scales. In situ observations find dominant types often associated to specific physical and chemical water properties. However, the mechanisms and spatiotemporal scales by which marine ecosystems are organized are largely not known. Here we investigate the spatiotemporal organization of phytoplankton communities by combining multisatellite data, notably high-resolution ocean-color maps of dominant types and altimetry-derived Lagrangian diagnostics of the surface transport. We find that the phytoplanktonic landscape is organized in (sub-)mesoscale patches (10-100 km) of dominant types separated by physical fronts induced by horizontal stirring. These physical fronts delimit niches supported by water masses of similar history and whose lifetimes are comparable with the timescale of the bloom onset (few weeks). The resonance between biological activity and physical processes suggest that the spatiotemporal (sub-)mesoscales associated to stirring are determinant in the observation and modeling of marine ecosystems.
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Affiliation(s)
- Francesco d’Ovidio
- Institut des Systémes Complexes—Paris Île-de-France, 57-59 rue Lohmond, 75005 Paris, France
- Laboratoire d’Océanographie et du Climat: Expérimentation et Approches Numériques—Institut Pierre Simon Laplace, Université Pierre et Marie Curie, BC 100, 4 place Jussieu, 75005 Paris, France
| | - Silvia De Monte
- École Normale Supérieure, Unité Mixte de Recherche 7625, Écologie et Évolution, 46 rue d’Ulm, 75005 Paris, France
- Université Pierre et Marie Curie-Paris 6, Unité Mixte de Recherche 7625, Écologie et Évolution, CC 237-7 quai Saint Bernard, 75005 Paris, France
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7625, Écologie et Évolution, 46 rue d'Ulm, 75005 Paris, France; and
| | - Séverine Alvain
- Laboratoire d’Océanologie et de Géosciences, Centre National de la Recherche Scientifique-Unité Mixte de Recherche 8187, 32 Avenue Foch, 62930 Wimereux, France
| | - Yves Dandonneau
- Laboratoire d’Océanographie et du Climat: Expérimentation et Approches Numériques—Institut Pierre Simon Laplace, Université Pierre et Marie Curie, BC 100, 4 place Jussieu, 75005 Paris, France
| | - Marina Lévy
- Laboratoire d’Océanographie et du Climat: Expérimentation et Approches Numériques—Institut Pierre Simon Laplace, Université Pierre et Marie Curie, BC 100, 4 place Jussieu, 75005 Paris, France
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Baltar F, Arístegui J, Gasol JM, Lekunberri I, Herndl GJ. Mesoscale eddies: hotspots of prokaryotic activity and differential community structure in the ocean. ISME JOURNAL 2010; 4:975-88. [PMID: 20357833 DOI: 10.1038/ismej.2010.33] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
To investigate the effects of mesoscale eddies on prokaryotic assemblage structure and activity, we sampled two cyclonic eddies (CEs) and two anticyclonic eddies (AEs) in the permanent eddy-field downstream the Canary Islands. The eddy stations were compared with two far-field (FF) stations located also in the Canary Current, but outside the influence of the eddy field. The distribution of prokaryotic abundance (PA), bulk prokaryotic heterotrophic activity (PHA), various indicators of single-cell activity (such as nucleic acid content, proportion of live cells, and fraction of cells actively incorporating leucine), as well as bacterial and archaeal community structure were determined from the surface to 2000 m depth. In the upper epipelagic layer (0-200 m), the effect of eddies on the prokaryotic community was more apparent, as indicated by the higher PA, PHA, fraction of living cells, and percentage of active cells incorporating leucine within eddies than at FF stations. Prokaryotic community composition differed also between eddy and FF stations in the epipelagic layer. In the mesopelagic layer (200-1000 m), there were also significant differences in PA and PHA between eddy and FF stations, although in general, there were no clear differences in community composition or single-cell activity. The effects on prokaryotic activity and community structure were stronger in AE than CE, decreasing with depth in both types of eddies. Overall, both types of eddies show distinct community compositions (as compared with FF in the epipelagic), and represent oceanic 'hotspots' of prokaryotic activity (in the epi- and mesopelagic realms).
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Affiliation(s)
- Federico Baltar
- Facultad de Ciencias del Mar, Universidad de Las Palmas de Gran Canaria, Campus Universitario de Tafira, Las Palmas de Gran Canaria, Spain.
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Dong C, Mavor T, Nencioli F, Jiang S, Uchiyama Y, McWilliams JC, Dickey T, Ondrusek M, Zhang H, Clark DK. An oceanic cyclonic eddy on the lee side of Lanai Island, Hawai'i. ACTA ACUST UNITED AC 2009. [DOI: 10.1029/2009jc005346] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Zenimoto K, Kitagawa T, Miyazaki S, Sasai Y, Sasaki H, Kimura S. The effects of seasonal and interannual variability of oceanic structure in the western Pacific North Equatorial Current on larval transport of the Japanese eel Anguilla japonica. JOURNAL OF FISH BIOLOGY 2009; 74:1878-1890. [PMID: 20735678 DOI: 10.1111/j.1095-8649.2009.02295.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
As the North Equatorial Current (NEC)-bifurcation is known to be related to El Niño-Southern Oscillation (ENSO) events, the influence of the position of the NEC bifurcation on transport success of the larval Japanese eel Anguilla japonica was investigated. Using a Lagrangian modelling approach, larval transport was simulated and the relative influence of El Niño and La Niña events and the NEC-bifurcation position on the success of particle transport analysed. The number of particles transported from the NEC to the Kuroshio tended to be lowest during El Niño years, and differences between La Niña and regular years were small. The transport success observed in simulations showed some relationships to annual A. japonica glass eel recruitment to Tanegashima Island over 1993 to 2001, but not in 2002. The study shows that particle tracking simulations can be used to improve knowledge of the oceanic migration of A. japonica but further studies are required, including comparisons with the effects on larval survival of fluctuations in temperature and food availability.
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Affiliation(s)
- K Zenimoto
- Ocean Research Institute, Graduate School of Frontier Sciences, University of Tokyo, Nakanoku, Tokyo 164-8639, Japan.
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37
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Eiler A, Hayakawa DH, Church MJ, Karl DM, Rappé MS. Dynamics of the SAR11 bacterioplankton lineage in relation to environmental conditions in the oligotrophic North Pacific subtropical gyre. Environ Microbiol 2009; 11:2291-300. [PMID: 19490029 DOI: 10.1111/j.1462-2920.2009.01954.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A quantitative PCR assay for the SAR11 clade of marine Alphaproteobacteria was applied to nucleic acids extracted from monthly depth profiles sampled over a 3-year period (2004-2007) at the open-ocean Station ALOHA (A Long-term Oligotrophic Habitat Assessment; 22 degrees 45'N, 158 degrees 00'W) in the oligotrophic North Pacific Ocean. This analysis revealed a high contribution (averaging 36% of 16S rRNA gene copies) of SAR11 to the total detected 16S rRNA gene copies over depths ranging from the surface layer to 4000 m, and revealed consistent spatial and temporal variation in the relative abundance of SAR11 16S rRNA gene copies. On average, a higher proportion of SAR11 rRNA gene copies were detected in the photic zone (< 175 m depth; mean = 38%) compared with aphotic (> 175 m depth; mean = 30%), and in the winter months compared with the summer (mean = 44% versus 33%, integrated over 175 m depth). Partial least square to latent structure projections identified environmental variables that correlate with variation in the absolute abundance of SAR11, and provided tools for developing a predictive model to explain time and depth-dependent variations in SAR11. Moreover, this information was used to hindcast temporal dynamics of the SAR11 clade between 1997 and 2006 using the existing HOT data set, which suggested that interannual variations in upper ocean SAR11 abundances were related to ocean-climate variability such as the El Niño Southern Oscillation.
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Affiliation(s)
- Alexander Eiler
- Hawaii Institute of Marine Biology, SOEST, University of Hawaii, Kaneohe, HI 96744, USA
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Ducklow HW, Doney SC, Steinberg DK. Contributions of long-term research and time-series observations to marine ecology and biogeochemistry. ANNUAL REVIEW OF MARINE SCIENCE 2009; 1:279-302. [PMID: 21141038 DOI: 10.1146/annurev.marine.010908.163801] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Time-series observations form a critical element of oceanography. New interdisciplinary efforts launched in the past two decades complement the few earlier, longer-running time series to build a better, though still poorly resolved, picture of lower-frequency ocean variability, the climate processes that drive variability, and the implications for food web dynamics, carbon storage, and climate feedbacks. Time series also enlarge our understanding of ecological processes and are integral for improving models of physical-biogeochemical-ecological ocean dynamics. The major time-series observatories go well beyond simple monitoring of core ocean properties, although that important activity forms the critical center of all time-series efforts. Modern ocean time series have major process and experimental components, entrain ancillary programs, and have integrated modeling programs for deriving a better understanding of the observations and the changing, three-dimensional ocean in which the observatories are embedded.
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Affiliation(s)
- Hugh W Ducklow
- The Ecosystems Center, Marine Biological Laboratory, Woods Hole, Massachusetts 02543, USA.
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39
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Cai P, Chen W, Dai M, Wan Z, Wang D, Li Q, Tang T, Lv D. A high-resolution study of particle export in the southern South China Sea based on234Th:238U disequilibrium. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jc004268] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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40
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McWilliams JC. The nature and consequences of oceanic eddies. OCEAN MODELING IN AN EDDYING REGIME 2008. [DOI: 10.1029/177gm03] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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41
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Eddies and upper-ocean nutrient supply. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/177gm09] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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Affiliation(s)
- Anthony F Michaels
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA.
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