1
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Kim M, Choi W, Jang CJ, Kang JH. Hidden underlying mechanisms for changes in mesozooplankton communities: Transport and eddy driven changes. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174336. [PMID: 38944310 DOI: 10.1016/j.scitotenv.2024.174336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 06/14/2024] [Accepted: 06/25/2024] [Indexed: 07/01/2024]
Abstract
Mesozooplankton communities have been used extensively as reliable climate change indicators, mainly because of their rapid growth and sensitivity to environmental changes. This study explored the modifications in the taxonomic composition of the mesozooplankton community and the associated physical changes of transport-driven, eddy-driven, and marine heatwaves in the summers of the last 14 years (2009-2022) within the mixed layer of the Ulleung Basin in the East Sea/Japan Sea, where surface waters have rapidly warmed in recent decades. A slight increase was observed in the abundance of mesozooplankton from 2009 (3709 inds.m-3) to 2022 (4231 inds.m-3), with two notable peaks in 2015 (11,377 inds.m-3) and 2020 (11,184 inds.m-3), which was mainly attributed to the prevalence of Noctiluca scintillans. The first peak in 2015 showed thaliaceans to be the next dominant taxa, in which the southward direction of meandering in East Korea Warm Current (EKWC), presence of the Ulleung warm eddy, lower volume of the Western Channel (V-west) of the Korea Strait, and marine heatwaves (MHWs) did not occur. In contrast to the first peak, the second peak in 2020 showed Pyrocystis pseudonoctiluca to be the next dominant species, which may have been transported and advected by the strong V-west and eastward direction of the EKWC and the occurrence of MHWs that allowed the persistence of the subtropical species P. pseudonoctiluca. Overall, the significant increases in the second dominant mesozooplankton taxa appeared to be affected by physical changes, including transport or eddy-driven changes, along with the occurrence of strong V-west, the direction of the EKWC, and the occurrence of MHWs, which may synergistically influence the increase in the second dominant taxa during summer. This study highlights the complex interplay between notable variations in mesozooplankton communities and environmental factors, highlighting the potential consequences of different physical changes (transport-driven and eddy-driven) in this regional ocean.
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Affiliation(s)
- Minju Kim
- Ecological Risk Research Department, Korea Institute of Ocean Science and Technology, Geoje 53201, Republic of Korea; Department of Ocean Science, University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Wonkeun Choi
- Department of Ocean Science, University of Science and Technology, Daejeon 34113, Republic of Korea; Ocean Circulation and Climate Research Department, Korea Institute of Ocean Science and Technology, Busan 49111, Republic of Korea
| | - Chan Joo Jang
- Department of Ocean Science, University of Science and Technology, Daejeon 34113, Republic of Korea; Ocean Circulation and Climate Research Department, Korea Institute of Ocean Science and Technology, Busan 49111, Republic of Korea; Ocean Science and Technology School, Korea Maritime and Ocean University, Busan 49112, Republic of Korea
| | - Jung-Hoon Kang
- Ecological Risk Research Department, Korea Institute of Ocean Science and Technology, Geoje 53201, Republic of Korea; Department of Ocean Science, University of Science and Technology, Daejeon 34113, Republic of Korea.
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2
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He T, Li J, Xie L, Zheng Q. Response of chlorophyll-a to rainfall event in the basin of the South China sea: Statistical analysis. MARINE ENVIRONMENTAL RESEARCH 2024; 199:106576. [PMID: 38839454 DOI: 10.1016/j.marenvres.2024.106576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 04/27/2024] [Accepted: 05/31/2024] [Indexed: 06/07/2024]
Abstract
Chlorophyll-a (Chl-a) is an essential ecological indicator, and affected by processes such as typhoons, mesoscale eddies, and Rossby waves. However, the impact of more frequent and widespread precipitation events on Chl-a seems to be overlooked. This study utilized remote sensing data and reanalysis data to investigate the response of Chl-a to 240 precipitation events in the central South China Sea from 2005 to 2019. The results indicate that precipitation events have a significant impact on Chl-a concentration. Following a precipitation event in 2019, the Chl-a concentration in the affected area increased by approximately 0.22 mg m-³ from the 3rd to the 7th day. The reasons for the increase in Chl-a concentration were the vertical mixing induced by wind stirring and the upwelling caused by wind stress curl, which transported nutrients to the euphotic zone, lowering the sea surface temperature and triggering a proliferation of phytoplankton. Additionally, dissolved nutrients in precipitation provided a nutrient source for Chl-a growth. The contributions of nutrient supply, wind speed, and wind stress curl to the increase in Chl-a concentration during precipitation events were 18%, 37%, and 45%, respectively. Precipitation events enhanced marine primary productivity, playing a crucial role in deepening our understanding of ocean-atmosphere interactions and their impact on marine ecosystem.
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Affiliation(s)
- Tao He
- Laboratory of Coastal Ocean Variation and Disaster Prediction, College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, 524088, China; Key Laboratory of Space Ocean Remote Sensing and Application, MNR, Beijing, 100081, China
| | - Junyi Li
- Laboratory of Coastal Ocean Variation and Disaster Prediction, College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, 524088, China; Key Lab Continents Deep Sea Climate Sources & Environments in Continent Shelf Sea and Deep Ocean, Zhanjiang, 524088, China.
| | - Lingling Xie
- Laboratory of Coastal Ocean Variation and Disaster Prediction, College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, 524088, China
| | - Quanan Zheng
- Laboratory of Coastal Ocean Variation and Disaster Prediction, College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, 524088, China
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Chen PWY, Olivia M, Gong GC, Jan S, Tsai AY. Viral Dynamics in the Tropical Pacific Ocean: A Comparison between Within and Outside a Warm Eddy. Viruses 2024; 16:937. [PMID: 38932229 PMCID: PMC11209615 DOI: 10.3390/v16060937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Revised: 06/02/2024] [Accepted: 06/06/2024] [Indexed: 06/28/2024] Open
Abstract
In mesoscale eddies, the chemical properties and biological composition are different from those in the surrounding water due to their unique physical processes. The mechanism of physical-biological coupling in warm-core eddies is unclear, especially because no studies have examined the effects of environmental factors on bacteria and viruses. The purpose of the present study was to examine the influence of an anticyclonic warm eddy on the relationship between bacterial and viral abundances, as well as viral activity (viral production), at different depths. At the core of the warm eddy, the bacterial abundance (0.48 to 2.82 × 105 cells mL-1) fluctuated less than that outside the eddy (1.12 to 7.03 × 105 cells mL-1). In particular, there was a four-fold higher viral-bacterial abundance ratio (VBR) estimated within the eddy, below the layer of the deep chlorophyll maximum, than outside the eddy. An anticyclonic warm eddy with downwelling at its center may contribute to viruses being transmitted directly into the deep ocean through adsorption on particulate organic matter while sinking. Overall, our findings provide valuable insights into the interaction between bacterial and viral abundances and their ecological mechanisms within a warm eddy.
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Affiliation(s)
- Patrichka Wei-Yi Chen
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung 202-24, Taiwan; (P.W.-Y.C.); (M.O.); (G.-C.G.)
- Doctoral Degree Program in Ocean Resource and Environmental Changes, National Taiwan Ocean University, Keelung 202-24, Taiwan
| | - Madeline Olivia
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung 202-24, Taiwan; (P.W.-Y.C.); (M.O.); (G.-C.G.)
- Doctoral Degree Program in Ocean Resource and Environmental Changes, National Taiwan Ocean University, Keelung 202-24, Taiwan
| | - Gwo-Ching Gong
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung 202-24, Taiwan; (P.W.-Y.C.); (M.O.); (G.-C.G.)
- Doctoral Degree Program in Ocean Resource and Environmental Changes, National Taiwan Ocean University, Keelung 202-24, Taiwan
- Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 202-24, Taiwan
| | - Sen Jan
- Institute of Oceanography, National Taiwan University, Taipei 106319, Taiwan;
| | - An-Yi Tsai
- Institute of Marine Environment and Ecology, National Taiwan Ocean University, Keelung 202-24, Taiwan; (P.W.-Y.C.); (M.O.); (G.-C.G.)
- Doctoral Degree Program in Ocean Resource and Environmental Changes, National Taiwan Ocean University, Keelung 202-24, Taiwan
- Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 202-24, Taiwan
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4
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Receveur A, Menkes C, Lengaigne M, Ariza A, Bertrand A, Dutheil C, Cravatte S, Allain V, Barbin L, Lebourges-Dhaussy A, Lehodey P, Nicol S. A rare oasis effect for forage fauna in oceanic eddies at the global scale. Nat Commun 2024; 15:4834. [PMID: 38844446 PMCID: PMC11156932 DOI: 10.1038/s41467-024-49113-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Accepted: 05/17/2024] [Indexed: 06/09/2024] Open
Abstract
Oceanic eddies are recognized as pivotal components in marine ecosystems, believed to concentrate a wide range of marine life spanning from phytoplankton to top predators. Previous studies have posited that marine predators are drawn to these eddies due to an aggregation of their forage fauna. In this study, we examine the response of forage fauna, detected by shipboard acoustics, across a broad sample of a thousand eddies across the world's oceans. While our findings show an impact of eddies on surface temperatures and phytoplankton in most cases, they reveal that only a minority (13%) exhibit significant effects on forage fauna, with only 6% demonstrating an oasis effect. We also show that an oasis effect can occur both in anticyclonic and cyclonic eddies, and that the few high-impact eddies are marked by high eddy amplitude and strong water-mass-trapping. Our study underscores the nuanced and complex nature of the aggregating role of oceanic eddies, highlighting the need for further research to elucidate how these structures attract marine predators.
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Affiliation(s)
- Aurore Receveur
- Oceanic Fisheries Programme, The Pacific Community, BP D5 98848, Noumea, New Caledonia.
- CESAB, FRB; 5 Rue de l'École de Médecine, 34000, Montpellier, France.
| | - Christophe Menkes
- ENTROPIE, IRD, CNRS, Ifremer, Université de la Réunion, Université de la Nouvelle-Calédonie, Nouméa, New Caledonia
| | | | - Alejandro Ariza
- MARBEC, Université Montpellier, IRD, Ifremer, CNRS, Sète, France
- DECOD, Ifremer, INRAE, Institut Agro, Nantes, France
| | - Arnaud Bertrand
- MARBEC, Université Montpellier, IRD, Ifremer, CNRS, Sète, France
| | - Cyril Dutheil
- MARBEC, Université Montpellier, IRD, Ifremer, CNRS, Sète, France
- Department of Physical Oceanography and Instrumentation, Leibniz Institute for Baltic Sea Research Warnemünde, Rostock, Germany
| | - Sophie Cravatte
- Université de Toulouse, LEGOS (IRD, CNES, CNRS, UT3), Toulouse, France
- IRD, Noumea, New Caledonia
| | - Valérie Allain
- Oceanic Fisheries Programme, The Pacific Community, BP D5 98848, Noumea, New Caledonia
| | - Laure Barbin
- Oceanic Fisheries Programme, The Pacific Community, BP D5 98848, Noumea, New Caledonia
- ENTROPIE, IRD, CNRS, Ifremer, Université de la Réunion, Université de la Nouvelle-Calédonie, Nouméa, New Caledonia
| | | | - Patrick Lehodey
- Oceanic Fisheries Programme, The Pacific Community, BP D5 98848, Noumea, New Caledonia
- Mercator Ocean international, 31400, Toulouse, France
| | - Simon Nicol
- Oceanic Fisheries Programme, The Pacific Community, BP D5 98848, Noumea, New Caledonia
- Institute for Applied Ecology, Centre for Conservation Ecology and Genomics, University of Canberra, Bruce, ACT 2617, Australia
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5
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Xing Q, Yu H, Wang H. Global mapping and evolution of persistent fronts in Large Marine Ecosystems over the past 40 years. Nat Commun 2024; 15:4090. [PMID: 38744883 PMCID: PMC11094120 DOI: 10.1038/s41467-024-48566-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Accepted: 05/06/2024] [Indexed: 05/16/2024] Open
Abstract
Ocean fronts, characterized by narrow zones with sharp changes in water properties, are vital hotspots for ecosystem services and key regulators of regional and global climates. Global change is reshaping the distribution of material and energy in the ocean; however, it remains unclear how fronts have varied in the last few decades. Here, we present a global, fine-scale digital atlas of persistent fronts around Large Marine Ecosystems and demonstrate significant global increases in both their occurrence and intensity. In subtropical regions (around boundary currents and upwelling systems) and polar regions, persistent frontal occurrence and intensity are rapidly increasing, while in tropical regions, they remain stable or slightly decrease. These enhancements may be respectively related to changes in boundary currents, upwelling, and sea ice retreat. This spatially heterogeneous trend holds important implications for the redistribution of front-related ecosystem services and air-sea interactions but has not been captured by representative high-resolution climate projections models or observation-assimilated ocean models.
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Affiliation(s)
- Qinwang Xing
- Institute of Marine Science and Technology, Shandong University, Qingdao, 266237, China
| | - Haiqing Yu
- Institute of Marine Science and Technology, Shandong University, Qingdao, 266237, China.
| | - Hui Wang
- Institute of Marine Science and Technology, Shandong University, Qingdao, 266237, China
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519080, China
- National Marine Environmental Forecasting Center, 100086, Beijing, China
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6
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Deogharia R, Gupta H, Sil S, Gangopadhyay A, Shee A. On the evidence of helico-spiralling recirculation within coherent cores of eddies using Lagrangian approach. Sci Rep 2024; 14:11014. [PMID: 38745064 DOI: 10.1038/s41598-024-61744-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Accepted: 05/09/2024] [Indexed: 05/16/2024] Open
Abstract
Oceanic eddies exhibit remarkable coherence and longevity compared to other transient features in the surrounding flow. They possess the ability to transport properties over extensive distances while maintaining their material identity intact. The Lagrangian Coherent Structure (LCS) framework has proven effective in capturing these coherent eddies, where they display a solid-body-like rotation. Although various LCS approaches have been employed to investigate different facets of coherent eddies, a comprehensive understanding of their three-dimensional structures and internal dynamics remains elusive. This study aims to advance our comprehension of coherent eddies' structural characteristics and delve into the precise nature of their internal dynamics by utilizing the Lagrangian Averaged Vorticity Deviation approach. Two eddies, one cyclonic and the other anti-cyclonic, were chosen from a high-resolution simulation carried out in the Bay of Bengal using the Regional Ocean Modeling System (ROMS). The findings unveil that these eddies have three-dimensional coherent cores resembling gently tapered cones that are broader at the surface and gradually narrow towards the bottom. Intriguingly, the dynamically coherent core of these eddies exhibits simultaneous upwelling and downwelling while maintaining their volumes during advection due to persistent material coherence. The three-dimensional trajectories followed by the fluid parcels inside the coherent core are helical. Their two-dimensional horizontal projections show alternating spiral bands of upwelling and downwelling which are the manifestations of Vortex Rossby Waves. These observations lead to a conceptual framework of a three-dimensional helico-spiralling recirculation pattern within the coherent cores of eddies.
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Affiliation(s)
- Rahul Deogharia
- Ocean Analysis and Modeling Laboratory, School of Earth, Ocean and Climate Sciences, Indian Institute of Technology Bhubaneswar, Khordha, Odisha, 752050, India.
| | - Hitesh Gupta
- Ocean Analysis and Modeling Laboratory, School of Earth, Ocean and Climate Sciences, Indian Institute of Technology Bhubaneswar, Khordha, Odisha, 752050, India
| | - Sourav Sil
- Ocean Analysis and Modeling Laboratory, School of Earth, Ocean and Climate Sciences, Indian Institute of Technology Bhubaneswar, Khordha, Odisha, 752050, India
| | - Avijit Gangopadhyay
- Ocean Analysis and Modeling Laboratory, School of Earth, Ocean and Climate Sciences, Indian Institute of Technology Bhubaneswar, Khordha, Odisha, 752050, India
- School for Marine Science and Technology, University of Massachusetts, Dartmouth, 02747, MA, USA
| | - Abhijit Shee
- Centre for Atmospheric and Oceanic Sciences, Indian Institute of Science, Bengaluru, Karnataka, 560012, India
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7
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Zhu Y, Mulholland MR, Bernhardt PW, Neeley AR, Widner B, Tapia AM, Echevarria MA. Nitrogen uptake rates and phytoplankton composition across contrasting North Atlantic Ocean coastal regimes north and south of Cape Hatteras. Front Microbiol 2024; 15:1380179. [PMID: 38784802 PMCID: PMC11113559 DOI: 10.3389/fmicb.2024.1380179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 04/17/2024] [Indexed: 05/25/2024] Open
Abstract
Understanding nitrogen (N) uptake rates respect to nutrient availability and the biogeography of phytoplankton communities is crucial for untangling the complexities of marine ecosystems and the physical, biological, and chemical forces shaping them. In the summer of 2016, we conducted measurements of bulk microbial uptake rates for six 15N-labeled substrates: nitrate, nitrite, ammonium, urea, cyanate, and dissolve free amino acids across distinct marine provinces, including the continental shelf of the Mid-and South Atlantic Bights (MAB and SAB), the Slope Sea, and the Gulf Stream, marking the first instance of simultaneously measuring six different N uptake rates in this dynamic region. Total measured N uptake rates were lowest in the Gulf Stream followed by the SAB. Notably, the MAB exhibited significantly higher N uptake rates compared to the SAB, likely due to the excess levels of pre-existing phosphorus present in the MAB. Together, urea and nitrate uptake contributed approximately 50% of the total N uptake across the study region. Although cyanate uptake rates were consistently low, they accounted for up to 11% of the total measured N uptake at some Gulf Stream stations. Phytoplankton groups were identified based on specific pigment markers, revealing a dominance of diatoms in the shelf community, while Synechococcus, Prochlorococcus, and pico-eukaryotes dominated in oligotrophic Gulf Stream waters. The reported uptake rates in this study were mostly in agreement with previous studies conducted in coastal waters of the North Atlantic Ocean. This study suggests there are distinct regional patterns of N uptake in this physically dynamic region, correlating with nutrient availability and phytoplankton community composition. These findings contribute valuable insights into the intricate interplay of biological and chemical factors shaping N dynamics in disparate marine ecosystems.
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Affiliation(s)
- Yifan Zhu
- Department of Ocean and Earth Sciences, Old Dominion University, Norfolk, VA, United States
- Department of Marine Sciences, University of Connecticut, Groton, CT, United States
| | - Margaret R. Mulholland
- Department of Ocean and Earth Sciences, Old Dominion University, Norfolk, VA, United States
| | - Peter W. Bernhardt
- Department of Ocean and Earth Sciences, Old Dominion University, Norfolk, VA, United States
| | | | - Brittany Widner
- Department of Ocean and Earth Sciences, Old Dominion University, Norfolk, VA, United States
| | - Alfonso Macías Tapia
- Department of Ocean and Earth Sciences, Old Dominion University, Norfolk, VA, United States
- Office of Education, National Oceanic and Atmospheric Administration, Silver Spring, MD, United States
| | - Michael A. Echevarria
- Department of Ocean and Earth Sciences, Old Dominion University, Norfolk, VA, United States
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8
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Wang C, Liu F. Influence of oceanic mesoscale eddies on the deep chlorophyll maxima. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170510. [PMID: 38286277 DOI: 10.1016/j.scitotenv.2024.170510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 01/14/2024] [Accepted: 01/26/2024] [Indexed: 01/31/2024]
Abstract
The deployment of the biogeochemical Argo network significantly enhances our understanding of the ecological effects of mesoscale eddies at different ocean depths. In this study, satellite data and more than one hundred thousand biogeochemical Argo float profiles were used to analyze the responses of the deep chlorophyll maximum (DCM) to mesoscale eddies. The DCM profiles were categorized into two types: DAM (adaptation maximum) and DBM (biomass maximum), based on their adaptation to light and maximum biomass characteristics. The variabilities in the DCM profiles in terms of latitude, seasonality, and their response to mesoscale eddies were subsequently investigated on a global scale. Our analysis demonstrates that light and nutrient availability explain a significant portion of the variability in the phytoplankton distribution across different regions and seasons. Statistical analysis reveals that cyclonic (anticyclonic) eddies enhance (weaken) the intensity of the DCM. The magnitude of this enhancement or weakening exhibits regional differences. Specifically, high-latitude regions are more influenced by eddies in terms of light-adapted DCM intensity, while in mid-latitude regions, eddies exhibit a stronger effect on the maximum biomass-driven DCM intensity. Moreover, our findings suggest that eddies in the North Atlantic Subtropical Gyre contribute to a downward shift in the euphotic zone depth, leading to an increased DCM depth and strengthened DCM intensity. However, in the equatorial region, eddies impact the DCM depth by influencing the nitracline (a layer in a body of water in which the nitrate concentration changes rapidly with depth). Similar patterns are frequently observed in different regions at the same latitude, providing a foundation for further detailed investigations of the DCM in specific areas.
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Affiliation(s)
- Changjie Wang
- School of Marine Sciences, Sun Yat-sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China
| | - Fenfen Liu
- School of Marine Sciences, Sun Yat-sen University, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-sen University, Zhuhai 519082, China.
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9
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Lévy M, Couespel D, Haëck C, Keerthi MG, Mangolte I, Prend CJ. The Impact of Fine-Scale Currents on Biogeochemical Cycles in a Changing Ocean. ANNUAL REVIEW OF MARINE SCIENCE 2024; 16:191-215. [PMID: 37352844 DOI: 10.1146/annurev-marine-020723-020531] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/25/2023]
Abstract
Fine-scale currents, O(1-100 km, days-months), are actively involved in the transport and transformation of biogeochemical tracers in the ocean. However, their overall impact on large-scale biogeochemical cycling on the timescale of years remains poorly understood due to the multiscale nature of the problem. Here, we summarize these impacts and critically review current estimates. We examine how eddy fluxes and upscale connections enter into the large-scale balance of biogeochemical tracers. We show that the overall contribution of eddy fluxes to primary production and carbon export may not be as large as it is for oxygen ventilation. We highlight the importance of fine scales to low-frequency natural variability through upscale connections and show that they may also buffer the negative effects of climate change on the functioning of biogeochemical cycles. Significant interdisciplinary efforts are needed to properly account for the cross-scale effects of fine scales on biogeochemical cycles in climate projections.
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Affiliation(s)
- Marina Lévy
- Sorbonne Université, Laboratoire d'Océanographie et du Climat: Expérimentations et Analyses Numériques de l'Institut Pierre Simon Laplace (LOCEAN-IPSL), CNRS/IRD/MNHN, Paris, France;
| | - Damien Couespel
- Norwegian Research Centre (NORCE), Bjerknes Centre for Climate Research, Bergen, Norway
| | - Clément Haëck
- Sorbonne Université, Laboratoire d'Océanographie et du Climat: Expérimentations et Analyses Numériques de l'Institut Pierre Simon Laplace (LOCEAN-IPSL), CNRS/IRD/MNHN, Paris, France;
| | - M G Keerthi
- Sorbonne Université, Laboratoire d'Océanographie et du Climat: Expérimentations et Analyses Numériques de l'Institut Pierre Simon Laplace (LOCEAN-IPSL), CNRS/IRD/MNHN, Paris, France;
| | - Inès Mangolte
- Sorbonne Université, Laboratoire d'Océanographie et du Climat: Expérimentations et Analyses Numériques de l'Institut Pierre Simon Laplace (LOCEAN-IPSL), CNRS/IRD/MNHN, Paris, France;
| | - Channing J Prend
- School of Oceanography, University of Washington, Seattle, Washington, USA
- Department of Environmental Science and Engineering, California Institute of Technology, Pasadena, California, USA
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10
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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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11
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Zhang L, Ma Y, Cai M, Zhong Y, Zhang Z, Li S. Chemodynamics of Polycyclic Aromatic Hydrocarbons and Their Alkylated and Nitrated Derivatives in the Yellow Sea and East China Sea. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:20292-20303. [PMID: 37867381 DOI: 10.1021/acs.est.3c07476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2023]
Abstract
The occurrence of continuously released polycyclic aromatic hydrocarbons (PAHs) in marginal seas is regulated by hydrological and biogeochemical processes; however, scarce knowledge is about their derivatives in marine environments. In this study, the dissolved and particulate PAHs and their alkylated/nitrated derivatives (A-PAHs/N-PAHs) in surface seawater of the southwestern Yellow Sea (YS) and northwestern East China Sea (ECS) during September 2022 were comprehensively discussed. Results confirm higher levels of Σ26PAHs (9.3-70 ng/L) and Σ43A-PAHs (13-76 ng/L) than Σ20N-PAHs (0.80-6.6 ng/L). The spatial heterogeneity of contaminants was regulated by substantial riverine runoff and ocean currents. Lagrangian Coherent Structure analysis further revealed the existence of a transport barrier at the shelf break of the southwestern YS where contaminants hardly crossed and tended to accumulate. The relationship between dissolved compounds and chlorophyll a indicated both biodegradation and the biological pump contributed to the depletion of PAHs and A-PAHs from surface seawater while the biological pump was the major driver for N-PAHs, despite their complicated water-particle partition behavior due to variations in physicochemical properties in the presence of nitro groups. Source identification demonstrated that pyrogenic and petrogenic sources dominated the YS and ECS, respectively, while photochemical transformations appeared more active in the YS.
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Affiliation(s)
- Lihong Zhang
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Yuxin Ma
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China
- Key Laboratory of Polar Science, Ministry of Natural Resources, Polar Research Institute of China, Shanghai 200136, China
| | - Minghong Cai
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China
- Key Laboratory of Polar Science, Ministry of Natural Resources, Polar Research Institute of China, Shanghai 200136, China
| | - Yisen Zhong
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Zhiwei Zhang
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Shuangzhao Li
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200030, China
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12
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Fayman PA, Salyuk PA, Budyansky MV, Burenin AV, Didov AA, Lipinskaya NA, Ponomarev VI, Udalov AA, Morgunov YN, Uleysky MY, Shkramada SS, Pichugin MK. Transport of the Tumen River water to the Far Eastern Marine Reserve (Posyet Bay) based on in situ, satellite data and Lagrangian modeling using ROMS current velocity output. MARINE POLLUTION BULLETIN 2023; 194:115414. [PMID: 37634316 DOI: 10.1016/j.marpolbul.2023.115414] [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: 03/24/2023] [Revised: 08/05/2023] [Accepted: 08/10/2023] [Indexed: 08/29/2023]
Abstract
We study physical mechanisms of the Tumen River water transport in the area of the Posyet Bay (Peter the Great Bay, Sea of Japan). This study is based on the satellite and in situ measurements, and numerical simulation of advection of river water by the current velocity simulated by Regional Ocean Model System (ROMS). The importance of this study is in identification of the reasons of the transport of pollutants into the area of the Far Eastern Marine Reserve. The results of the study showed that such reasons are wind currents and mesoscale cyclonic eddies. These eddies were originally detected on satellite imagery and CTD and bio-optical measurements. The anomalies in the form of spots of the chlorophyll a (CHL) increased concentration were detected on satellite images in fall 2009. The oceanographic sections of CTD and bio-optical measurements through the anomalies show that they are cyclonic eddies. These eddies consist of two cores - upper and lower. The upper core is filled with river waters with low salinity, high values of CHL and colored dissolved organic matter content (CDOM). The lower core is filled with cold saline waters. The ROMS results show that eddies are generated as a result of symmetrical and centrifugal instabilities.
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Affiliation(s)
- Pavel A Fayman
- V.I. Il'ichev Pacific Oceanological Institute FEB RAS, 43, Baltiyskaya Street, Vladivostok 690041, Russia
| | - Pavel A Salyuk
- V.I. Il'ichev Pacific Oceanological Institute FEB RAS, 43, Baltiyskaya Street, Vladivostok 690041, Russia
| | - Maxim V Budyansky
- V.I. Il'ichev Pacific Oceanological Institute FEB RAS, 43, Baltiyskaya Street, Vladivostok 690041, Russia
| | - Alexandr V Burenin
- V.I. Il'ichev Pacific Oceanological Institute FEB RAS, 43, Baltiyskaya Street, Vladivostok 690041, Russia
| | - Aleksandr A Didov
- V.I. Il'ichev Pacific Oceanological Institute FEB RAS, 43, Baltiyskaya Street, Vladivostok 690041, Russia
| | - Nadezhda A Lipinskaya
- V.I. Il'ichev Pacific Oceanological Institute FEB RAS, 43, Baltiyskaya Street, Vladivostok 690041, Russia
| | - Vladimir I Ponomarev
- V.I. Il'ichev Pacific Oceanological Institute FEB RAS, 43, Baltiyskaya Street, Vladivostok 690041, Russia
| | - Aleksandr A Udalov
- V.I. Il'ichev Pacific Oceanological Institute FEB RAS, 43, Baltiyskaya Street, Vladivostok 690041, Russia
| | - Yuri N Morgunov
- V.I. Il'ichev Pacific Oceanological Institute FEB RAS, 43, Baltiyskaya Street, Vladivostok 690041, Russia
| | - Michael Yu Uleysky
- V.I. Il'ichev Pacific Oceanological Institute FEB RAS, 43, Baltiyskaya Street, Vladivostok 690041, Russia.
| | - Sergey S Shkramada
- V.I. Il'ichev Pacific Oceanological Institute FEB RAS, 43, Baltiyskaya Street, Vladivostok 690041, Russia
| | - Mikhail K Pichugin
- V.I. Il'ichev Pacific Oceanological Institute FEB RAS, 43, Baltiyskaya Street, Vladivostok 690041, Russia
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13
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Lovecchio E, Henson S, Carvalho F, Briggs N. Oxygen Variability in the Offshore Northern Benguela Upwelling System From Glider Data. JOURNAL OF GEOPHYSICAL RESEARCH. OCEANS 2022; 127:e2022JC019063. [PMID: 36589533 PMCID: PMC9788292 DOI: 10.1029/2022jc019063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 10/17/2022] [Accepted: 10/20/2022] [Indexed: 06/17/2023]
Abstract
Despite their role in modulating the marine ecosystem, variability and drivers of low-oxygen events in the offshore northern Benguela Upwelling System (BenUS) have been rarely investigated due to the events' episodicity which is difficult to resolve using shipboard measurements. We address this issue using 4 months of high-resolution glider data collected between February and June 2018, 100 km offshore at 18°S. We find that oxygen (O2) concentrations in the offshore northern Benguela are determined by the subsurface alternation of low-oxygen Angola-derived water and oxygenated water from the south at 100-500 m depth. We observe intermittent hypoxia (O2 < 60 μmol kg-1) which occurs on average for ∼30% of the 4 months deployment and is driven by the time-varying subsurface pulses of Angola-derived tropical water. Hypoxic events are rather persistent at depths of 300-450 m, while they are more sporadic and have weekly duration at shallower depths (100-300 m). We find extreme values of hypoxia, with O2 minima of 16 μmol kg-1, associated with an anticyclonic eddy spinning from the undercurrent flowing on the BenUS shelf and showing no surface signature. Fine-scale patchiness and water mass mixing are associated with cross-frontal stirring by a large anticyclone recirculating tropical water into the northern BenUS. The dominance of physical drivers and their high variability on short time scales reveal a dynamic coupling between Angola and Benguela, calling for long-term and high-resolution measurements and studies focusing on future changes of both tropical O2 minima and lateral fluxes in this region.
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Affiliation(s)
| | | | | | - Nathan Briggs
- National Oceanography CentreEuropean WaySouthamptonUK
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14
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Anticyclonic eddies aggregate pelagic predators in a subtropical gyre. Nature 2022; 609:535-540. [PMID: 36071164 DOI: 10.1038/s41586-022-05162-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 07/22/2022] [Indexed: 11/08/2022]
Abstract
Ocean eddies are coherent, rotating features that can modulate pelagic ecosystems across many trophic levels. These mesoscale features, which are ubiquitous at mid-latitudes1, may increase productivity of nutrient-poor regions2,3, accumulate prey4 and modulate habitat conditions in the water column5. However, in nutrient-poor subtropical gyres-the largest marine biome-the role of eddies in modulating behaviour throughout the pelagic predator community remains unknown despite predictions for these gyres to expand6 and pelagic predators to become increasingly important for food security7. Using a large-scale fishery dataset in the North Pacific Subtropical Gyre, we show a pervasive pattern of increased pelagic predator catch inside anticyclonic eddies relative to cyclones and non-eddy areas. Our results indicate that increased mesopelagic prey abundance in anticyclone cores4,8 may be attracting diverse predators, forming ecological hotspots where these predators aggregate and exhibit increased abundance. In this energetically quiescent gyre, we expect that isolated mesoscale features (and the habitat conditions in them) exhibit primacy over peripheral submesoscale dynamics in structuring the foraging opportunities of pelagic predators. Our finding that eddies influence coupling of epi- to mesopelagic communities corroborates the growing evidence that deep scattering layer organisms are vital prey for a suite of commercially important predator species9 and, thus, provide valuable ecosystem services.
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15
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Fahlbusch JA, Czapanskiy MF, Calambokidis J, Cade DE, Abrahms B, Hazen EL, Goldbogen JA. Blue whales increase feeding rates at fine-scale ocean features. Proc Biol Sci 2022; 289:20221180. [PMID: 35975432 PMCID: PMC9382224 DOI: 10.1098/rspb.2022.1180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Marine predators face the challenge of reliably finding prey that is patchily distributed in space and time. Predators make movement decisions at multiple spatial and temporal scales, yet we have a limited understanding of how habitat selection at multiple scales translates into foraging performance. In the ocean, there is mounting evidence that submesoscale (i.e. less than 100 km) processes drive the formation of dense prey patches that should hypothetically provide feeding hot spots and increase predator foraging success. Here, we integrated environmental remote-sensing with high-resolution animal-borne biologging data to evaluate submesoscale surface current features in relation to the habitat selection and foraging performance of blue whales in the California Current System. Our study revealed a consistent functional relationship in which blue whales disproportionately foraged within dynamic aggregative submesoscale features at both the regional and feeding site scales across seasons, regions and years. Moreover, we found that blue whale feeding rates increased in areas with stronger aggregative features, suggesting that these features indicate areas of higher prey density. The use of fine-scale, dynamic features by foraging blue whales underscores the need to take these features into account when designating critical habitat and may help inform strategies to mitigate the impacts of human activities for the species.
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Affiliation(s)
- James A. Fahlbusch
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA, USA,Cascadia Research Collective, Olympia, WA, USA
| | - Max F. Czapanskiy
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA, USA
| | | | - David E. Cade
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA, USA
| | - Briana Abrahms
- Center for Ecosystem Sentinels, Department of Biology, University of Washington, Seattle, WA, USA
| | - Elliott L. Hazen
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA, USA,Environmental Research Division, NOAA Southwest Fisheries Science Center, Monterey, CA, USA
| | - Jeremy A. Goldbogen
- Hopkins Marine Station, Department of Biology, Stanford University, Pacific Grove, CA, USA
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16
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Fourquez M, Strzepek RF, Ellwood MJ, Hassler C, Cabanes D, Eggins S, Pearce I, Deppeler S, Trull TW, Boyd PW, Bressac M. Phytoplankton Responses to Bacterially Regenerated Iron in a Southern Ocean Eddy. Microorganisms 2022; 10:microorganisms10081655. [PMID: 36014073 PMCID: PMC9413495 DOI: 10.3390/microorganisms10081655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 08/07/2022] [Accepted: 08/09/2022] [Indexed: 11/16/2022] Open
Abstract
In the Subantarctic sector of the Southern Ocean, vertical entrainment of iron (Fe) triggers the seasonal productivity cycle but diminishing physical supply during the spring to summer transition forces microbial assemblages to rapidly acclimate. Here, we tested how phytoplankton and bacteria within an isolated eddy respond to different dissolved Fe (DFe)/ligand inputs. We used three treatments: one that mimicked the entrainment of new DFe (Fe-NEW), another in which DFe was supplied from bacterial regeneration of particles (Fe-REG), and a control with no addition of DFe (Fe-NO). After 6 days, 3.5 (Fe-NO, Fe-NEW) to 5-fold (Fe-REG) increases in Chlorophyll a were observed. These responses of the phytoplankton community were best explained by the differences between the treatments in the amount of DFe recycled during the incubation (Fe-REG, 15% recycled c.f. 40% Fe-NEW, 60% Fe-NO). This additional recycling was more likely mediated by bacteria. By day 6, bacterial production was comparable between Fe-NO and Fe-NEW but was approximately two-fold higher in Fe-REG. A preferential response of phytoplankton (haptophyte-dominated) relative to high nucleic acid (HNA) bacteria was also found in the Fe-REG treatment while the relative proportion of diatoms increased faster in the Fe-NEW and Fe-NO treatments. Comparisons between light and dark incubations further confirmed the competition between picophytoplankton and HNA for DFe. Overall, our results demonstrate great versatility by microorganisms to use different Fe sources that results in highly efficient Fe recycling within surface waters. This study also encourages future research to further investigate the interactions between functional groups of microbes (e.g. HNA and cyanobacteria) to better constraint modeling in Fe and carbon biogeochemical cycles.
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Affiliation(s)
- Marion Fourquez
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart 7004, Australia
- Antarctic Climate and Ecosystems CRC, University of Tasmania, Hobart 7004, Australia
- Aix Marseille Université, Université de Toulon, CNRS, IRD, MIO UMR 110, 13288 Marseille, France
- Correspondence:
| | - Robert F. Strzepek
- Australian Antarctic Program Partnership (AAPP), Institute for Marine and Antarctic Studies, University of Tasmania, Hobart 7004, Australia
| | - Michael J. Ellwood
- Research School of Earth Sciences, Australian National University, Canberra 2601, Australia
| | - Christel Hassler
- Marine and Lake Biogeochemistry, Department F.-A. Forel, University of Geneva, 1205 Geneva, Switzerland
- Institute of Earth Sciences, University of Lausanne, 1015 Lausanne, Switzerland
| | - Damien Cabanes
- Marine and Lake Biogeochemistry, Department F.-A. Forel, University of Geneva, 1205 Geneva, Switzerland
| | - Sam Eggins
- Research School of Earth Sciences, Australian National University, Canberra 2601, Australia
| | - Imojen Pearce
- Australian Antarctic Division (AAD), Kingston 7050, Australia
| | - Stacy Deppeler
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart 7004, Australia
- National Institute of Water and Atmospheric Research, Wellington 6021, New Zealand
| | - Thomas W. Trull
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart 7004, Australia
- Antarctic Climate and Ecosystems CRC, University of Tasmania, Hobart 7004, Australia
- Climate Science Centre, Oceans and Atmosphere, Commonwealth Scientific and Industrial Research Organisation, Hobart 7004, Australia
| | - Philip W. Boyd
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart 7004, Australia
- Antarctic Climate and Ecosystems CRC, University of Tasmania, Hobart 7004, Australia
| | - Matthieu Bressac
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart 7004, Australia
- Laboratoire d’Océanographie de Villefranche, Sorbonne Université, CNRS, 06230 Villefranche-sur-Mer, France
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17
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Satellite Altimetry: Achievements and Future Trends by a Scientometrics Analysis. REMOTE SENSING 2022. [DOI: 10.3390/rs14143332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Scientometric reviews, facilitated by computational and visual analytical approaches, allow researchers to gain a thorough understanding of research trends and areas of concentration from a large number of publications. With the fast development of satellite altimetry, which has been effectively applied to a wide range of research topics, it is timely to summarize the scientific achievements of the previous 50 years and identify future trends in this field. A comprehensive overview of satellite altimetry was presented using a total of 8541 publications from the Web of Science Core Collection covering the years from 1970 to 2021. We begin by presenting the fundamental statistical results of the publications, such as the annual number of papers, study categories, countries/regions, afflictions, journals, authors, and keywords, in order to provide a comprehensive picture of satellite altimetry research. We discuss the co-occurrence of the authors in order to reveal the global collaboration network of satellite altimetry research. Finally, we utilised co-citation networks to detect the development trend and associated crucial publications for various specific topics. The findings show that satellite altimetry research has been changed immensely during the last half-century. The United States, France, China, England, and Germany made the most significant contributions in the field of satellite altimetry. The analysis reveals a clear link between technology advancements and the trend in satellite altimetry research. As a result, wide swath altimetry, GNSS-reflectometry, laser altimetry, terrestrial hydrology, and deep learning are among the most frontier study subjects. The findings of this work could guide a thorough understanding of satellite altimetry’s overall development and research front.
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18
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Lu Y, Zhang Y, Wang J, Zhang M, Wu Y, Xiao X, Xu J. Dynamics in Bacterial Community Affected by Mesoscale Eddies in the Northern Slope of the South China Sea. MICROBIAL ECOLOGY 2022; 83:823-836. [PMID: 34272992 DOI: 10.1007/s00248-021-01816-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 07/02/2021] [Indexed: 06/13/2023]
Abstract
Mesoscale eddies are common oceanographic processes that can enhance primary productivity by transporting nutrients to the euphotic zone. In the northern South China Sea (SCS), eddies were frequently found to promote the exchange between the nutrient-rich shelf water and the oligotrophic water at the slope area. However, the response of bacterial community to eddy perturbations remains unclear. In the present study, we examined the variation of bacterial community under the impact of eddies in early spring and summer. The results showed that both the summer cyclonic eddy and spring anticyclonic eddy enhanced the bacterial abundance in surface water. The bacterial community composition and their functional potentials of surface samples were also influenced by the summer cyclonic eddy, while no significant change was observed in the case of spring anticyclonic eddy. Salinity and nutrients, which varied between the inside and outside of the eddies, were the significant factors explaining the differentiation of the community composition and related functions. Taken together, the results of our present study reveal the effects of mesoscale eddies on the bacterial community and associated metagenomes, providing a better understanding of the dynamics of bacteria in the slope ecosystem of the SCS.
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Affiliation(s)
- Ye Lu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
- School of Oceanography, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yu Zhang
- School of Oceanography, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jiahua Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
- School of Oceanography, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Miao Zhang
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, 200062, China
| | - Ying Wu
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, 200062, China
| | - Xiang Xiao
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jun Xu
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
- School of Oceanography, Shanghai Jiao Tong University, Shanghai, 200240, China.
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19
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Ferreira A, Dias J, Brotas V, Brito AC. A perfect storm: An anomalous offshore phytoplankton bloom event in the NE Atlantic (March 2009). THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:151253. [PMID: 34710413 DOI: 10.1016/j.scitotenv.2021.151253] [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: 07/28/2021] [Revised: 10/21/2021] [Accepted: 10/22/2021] [Indexed: 06/13/2023]
Abstract
While primary productivity is more stable in oceanic regions, it may vary to a great extent with the proximity to coasts, where mesoscale processes may intertwine and shape phytoplankton community composition and biomass. Sometimes, this may lead to the development of anomalous phytoplankton blooms (i.e., episodic blooms that exceed several times the average phytoplankton biomass). A massive bloom observed off the Western Iberian Coast (SW Europe) during March 2009 prompted a full investigation on its spatial and temporal extent, its causes, and its potential impact on the ecosystem. Results revealed that the March 2009 bloom was both novel in terms of biomass in a regional context and one of the largest anomalous blooms until now described in terms of relative magnitude. Its causes were due to a concurrence of long-term (deep winter MLD) and short-term factors (coastal upwelling, sudden changes in the water column, consistent offshore water transport). Its impact on the regional ecosystem is difficult to gauge, although the high concentrations of particulate organic carbon at surface during the bloom period suggests that it may have had a significant local impact. Since climate change is expected to increase the frequency and intensity of extreme weather events, it is possible that anomalous blooms will also become more frequent, expanding their role in shaping carbon export and food webs. These results are crucial for the monitoring of the Western Iberian Coast and are applicable to other complex coastal upwelling regions where phytoplankton biomass and variability have a crucial link to fisheries.
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Affiliation(s)
- Afonso Ferreira
- MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal.
| | - Joaquim Dias
- MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; Departamento de Engenharia Geográfica, Geofísica e Energia (DEGGE), Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Vanda Brotas
- MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; Departamento de Biologia Vegetal, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
| | - Ana C Brito
- MARE - Marine and Environmental Sciences Centre, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; Departamento de Biologia Vegetal, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal
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20
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Braun CD, Arostegui MC, Thorrold SR, Papastamatiou YP, Gaube P, Fontes J, Afonso P. The Functional and Ecological Significance of Deep Diving by Large Marine Predators. ANNUAL REVIEW OF MARINE SCIENCE 2022; 14:129-159. [PMID: 34416123 DOI: 10.1146/annurev-marine-032521-103517] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Many large marine predators make excursions from surface waters to the deep ocean below 200 m. Moreover, the ability to access meso- and bathypelagic habitats has evolved independently across marine mammals, reptiles, birds, teleost fishes, and elasmobranchs. Theoretical and empirical evidence suggests a number of plausible functional hypotheses for deep-diving behavior. Developing ways to test among these hypotheses will, however, require new ways to quantify animal behavior and biophysical oceanographic processes at coherent spatiotemporal scales. Current knowledge gaps include quantifying ecological links between surface waters and mesopelagic habitats and the value of ecosystem services provided by biomass in the ocean twilight zone. Growing pressure for ocean twilight zone fisheries creates an urgent need to understand the importance of the deep pelagic ocean to large marine predators.
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Affiliation(s)
- Camrin D Braun
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA;
- School of Aquatic and Fishery Sciences, University of Washington, Seattle, Washington 98195, USA
| | - Martin C Arostegui
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA;
- Air-Sea Interaction and Remote Sensing Department, Applied Physics Laboratory, University of Washington, Seattle, Washington 98105, USA
| | - Simon R Thorrold
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA;
| | - Yannis P Papastamatiou
- Institute of Environment, Department of Biological Sciences, Florida International University, Miami, Florida 33181, USA
| | - Peter Gaube
- Air-Sea Interaction and Remote Sensing Department, Applied Physics Laboratory, University of Washington, Seattle, Washington 98105, USA
| | - Jorge Fontes
- Okeanos and Institute of Marine Research, University of the Azores, 9901-862 Horta, Portugal
| | - Pedro Afonso
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA;
- Okeanos and Institute of Marine Research, University of the Azores, 9901-862 Horta, Portugal
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21
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From 1/4° to 1/8°: Influence of Spatial Resolution on Eddy Detection Using Altimeter Data. REMOTE SENSING 2021. [DOI: 10.3390/rs14010149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A substantial portion of ocean eddies, especially small ones, may be missed due to insufficient spatial or temporal sampling by satellite altimetry. In order to illustrate the influence of spatial resolution on eddy detection, this study provides a comparison of eddy identification, tracking, and analysis between two sets of merged altimeter data with spatial resolutions of 1/4° and 1/8°. One main study area (the Mediterranean Sea), and three confirmatory areas (the South-China Sea, the North-West Pacific, and the South-East Pacific) are chosen. The results show that the number and density of eddies captured by the 1/8° data are about twice as much as those captured by the 1/4° data, while the ratios of corresponding eddy parameters, i.e., radius, amplitude, (eddy kinetic energy (EKE)) are about 0.6–0.8 (1.3) for the two datasets (1/8° ÷ 1/4°). Long-term eddy tracking (1993–2018) is conducted in the Mediterranean Sea, indicating that the improvement in spatial resolution will increase the observed values of both the lifetime and the propagation distance of robust eddies. The number of eddies identified using the 1/4° data only accounts for ~30% to 60% of those identified using the 1/8° data. However, for eddies that can be detected using the two datasets, ~5% to 10% present errors (i.e., confusion). In comparison between the four regions, we find that for the enclosed seas with complex conditions, the increase in spatial resolution may lead to more significant improvements in the efficiency and accuracy of eddy detection.
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22
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Clayton S, Palevsky HI, Thompson L, Quay PD. Synoptic Mesoscale to Basin Scale Variability in Biological Productivity and Chlorophyll in the Kuroshio Extension Region. JOURNAL OF GEOPHYSICAL RESEARCH. OCEANS 2021; 126:e2021JC017782. [PMID: 35865352 PMCID: PMC9286389 DOI: 10.1029/2021jc017782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/21/2021] [Accepted: 10/02/2021] [Indexed: 06/15/2023]
Abstract
The Kuroshio current separates from the Japanese coast to become the eastward flowing Kuroshio Extension (KE) characterized by a strong latitudinal density front, high levels of mesoscale (eddy) energy, and high chlorophyll a (Chl). While satellite measurements of Chl show evidence of the impact of mesoscale eddies on the standing stock of phytoplankton, there have been very limited synoptic, spatially resolved in situ estimates of productivity in this region. Here, we present underway measurements of oxygen/argon supersaturation (ΔO2/Ar), a tracer of net biological productivity, for the KE made in spring, summer, and early autumn. We find large seasonal differences in the relationships between ΔO2/Ar, Chl, and sea level anomaly (SLA), a proxy for local thermocline depth deviations driven by mesoscale eddies derived from satellite observations. We show that the KE is a pronounced hotspot of high ΔO2/Ar in spring, but corresponding surface Chl values are low and have no correlation with ΔO2/Ar. In summer, there is a hotspot of productivity associated with the Oyashio front, where ΔO2/Ar and Chl are strongly positively correlated. In autumn, ΔO2/Ar and Chl are consistently low throughout the region and also positively correlated. By combining our analysis of the in situ ΔO2/Ar data with complementary Argo, BGC-Argo, repeat hydrography, and SLA observations, we infer the combination of physical and biological controls that drive the observed distributions of ΔO2/Ar and Chl. We find that the KE and Oyashio currents both act to supply nutrients laterally, fueling regions of high productivity in spring and summer, respectively.
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Affiliation(s)
- Sophie Clayton
- Department of Ocean and Earth SciencesOld Dominion UniversityNorfolkVAUSA
| | | | | | - Paul D. Quay
- School of OceanographyUniversity of WashingtonSeattleWAUSA
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Ma C, Zhao J, Ai B, Sun S, Zhang G, Huang W, Wang G. Assessing responses of phytoplankton to consecutive typhoons by combining Argo, remote sensing and numerical simulation data. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 790:148086. [PMID: 34098270 DOI: 10.1016/j.scitotenv.2021.148086] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/11/2021] [Accepted: 05/24/2021] [Indexed: 06/12/2023]
Abstract
Typhoons can affect various hydrodynamic processes, such as upwelling, vertical mixing, and entrainment, which in turn influence the growth and redistribution of phytoplankton. In this study, responses of phytoplankton to consecutive typhoons Barijat and Mangkhut in summer 2018 in the northern South China Sea (NSCS) were investigated through combining remote sensing, numerical simulation, and Argo profile data. Variations of physical and biological properties induced by Barijat and Mangkhut over the study region were observed. Regional chlorophyll-a (Chla) algorithms over the NSCS were assessed in order to accurately quantify typhoon-induced variations of phytoplankton. Chla concentration decreased slightly over the region of interest after the passage of Barijiat while increased obviously after the passage of Mangkhut. Satellite-derived Chla increased by ~63% on average after the consecutive typhoons. Responses of phytoplankton size structure (PSS) were further investigated over the continental shelf and the deep ocean in the NSCS. For the continental shelf, the increment of micro- and nano-phytoplankton was about 1.5-fold as high as that of pico-phytoplankton, compared with a 0.5-fold increment for the deep ocean. This study attested the discrepant responses of different phytoplankton size classes to typhoons. It was of great significance to expand our understanding of ocean physical and ecological responses to extreme phenomena. Our finding underscores the potential of remote sensing to investigate typhoon-induced variation of PSS and could be the key to accurately assess typhoon-induced carbon fluxes, primary production, and potential fishing ground in the future.
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Affiliation(s)
- Chunlei Ma
- School of Marine Sciences, Sun Yat-sen University, Zhuhai 519082, Guangdong, China
| | - Jun Zhao
- School of Marine Sciences, Sun Yat-sen University, Zhuhai 519082, Guangdong, China; Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), Zhuhai 519000, Guangdong, China; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Guangzhou 510275, Guangdong, China; Pearl River Estuary Marine Ecosystem Research Station, Ministry of Education, Zhuhai 519000, China.
| | - Bin Ai
- School of Marine Sciences, Sun Yat-sen University, Zhuhai 519082, Guangdong, China; Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), Zhuhai 519000, Guangdong, China; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Guangzhou 510275, Guangdong, China
| | - Shaojie Sun
- School of Marine Sciences, Sun Yat-sen University, Zhuhai 519082, Guangdong, China; Southern Laboratory of Ocean Science and Engineering (Guangdong, Zhuhai), Zhuhai 519000, Guangdong, China; Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, Guangzhou 510275, Guangdong, China
| | - Guang Zhang
- School of Marine Sciences, Sun Yat-sen University, Zhuhai 519082, Guangdong, China
| | - Wei Huang
- School of Marine Sciences, Sun Yat-sen University, Zhuhai 519082, Guangdong, China
| | - Guifen Wang
- College of Oceanography, Hohai University, Nanjing 210098, China
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25
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Cornec M, Laxenaire R, Speich S, Claustre H. Impact of Mesoscale Eddies on Deep Chlorophyll Maxima. GEOPHYSICAL RESEARCH LETTERS 2021; 48:e2021GL093470. [PMID: 34433995 PMCID: PMC8365668 DOI: 10.1029/2021gl093470] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 06/26/2021] [Accepted: 06/29/2021] [Indexed: 06/13/2023]
Abstract
Deep Chlorophyll Maxima (DCM) are ubiquitous features in stratified oceanic systems. Their establishment and maintenance result from hydrographical stability favoring specific environmental conditions with respect to light and nutrient availability required for phytoplankton growth. This stability can potentially be challenged by mesoscale eddies impacting the water column's vertical structure and thus the environmental parameters that condition the subsistence of DCMs. Here, data from the global BGC-Argo float network are collocated with mesoscale eddies to explore their impact on DCMs. We show that cyclonic eddies, by providing optimal light and nutrient conditions, increase the occurrence of DCMs characterized by Deep Biomass Maxima for phytoplankton. In contrast, DCMs in anticyclonic eddies seem to be driven by photoacclimation as they coincide with Deep Acclimation Maxima without biomass accumulation. These findings suggest that the two types of eddies potentially have different impacts on the role of DCMs in global primary production.
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Affiliation(s)
- Marin Cornec
- Laboratoire d'Océanographie de VillefrancheCNRS & Sorbonne UniversitéLOVVillefranche‐sur‐MerFrance
| | - Rémi Laxenaire
- Center for Ocean‐Atmospheric Prediction StudiesFlorida State UniversityTallahasseeFLUSA
- Laboratoire de Météorologie DynamiqueLMD‐IPSLUMREcole PolytechniqueENSCNRSParisFrance
| | - Sabrina Speich
- Laboratoire de Météorologie DynamiqueLMD‐IPSLUMREcole PolytechniqueENSCNRSParisFrance
| | - Hervé Claustre
- Laboratoire d'Océanographie de VillefrancheCNRS & Sorbonne UniversitéLOVVillefranche‐sur‐MerFrance
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26
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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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27
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Baudena A, Ser-Giacomi E, D’Onofrio D, Capet X, Cotté C, Cherel Y, D’Ovidio F. Fine-scale structures as spots of increased fish concentration in the open ocean. Sci Rep 2021; 11:15805. [PMID: 34349142 PMCID: PMC8338936 DOI: 10.1038/s41598-021-94368-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 06/24/2021] [Indexed: 02/07/2023] Open
Abstract
Oceanic frontal zones have been shown to deeply influence the distribution of primary producers and, at the other extreme of the trophic web, top predators. However, the relationship between these structures and intermediate trophic levels is much more obscure. In this paper we address this knowledge gap by comparing acoustic measurements of mesopelagic fish concentrations to satellite-derived fine-scale Lagrangian Coherent Structures in the Indian sector of the Southern Ocean. First, we demonstrate that higher fish concentrations occur more frequently in correspondence with strong Lagrangian Coherent Structures. Secondly, we illustrate that, while increased fish densities are more likely to be observed over these structures, the presence of a fine-scale feature does not imply a concomitant fish accumulation, as other factors affect fish distribution. Thirdly, we show that, when only chlorophyll-rich waters are considered, front intensity modulates significantly more the local fish concentration. Finally, we discuss a model representing fish movement along Lagrangian features, specifically built for mid-trophic levels. Its results, obtained with realistic parameters, are qualitatively consistent with the observations and the spatio-temporal scales analysed. Overall, these findings may help to integrate intermediate trophic levels in trophic models, which can ultimately support management and conservation policies.
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Affiliation(s)
- Alberto Baudena
- grid.462844.80000 0001 2308 1657Sorbonne Université, CNRS, IRD, MNHN, Laboratoire d’Océanographie et du Climat: Expérimentations et Approches Numériques (LOCEAN-IPSL), Paris, France ,Sorbonne Université,CNRS, Laboratoire d’Océanographie de Villefranche, UMR 7093 LOV, Villefranche-sur-Mer, France
| | - Enrico Ser-Giacomi
- grid.462844.80000 0001 2308 1657Sorbonne Université, CNRS, IRD, MNHN, Laboratoire d’Océanographie et du Climat: Expérimentations et Approches Numériques (LOCEAN-IPSL), Paris, France ,grid.116068.80000 0001 2341 2786Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 02139 Cambridge, MA USA
| | - Donatella D’Onofrio
- grid.435667.50000 0000 9466 4203Institute of Atmospheric Sciences and Climate, National Research Council (CNR-ISAC), Torino, Italy ,grid.5477.10000000120346234
Copernicus Institute of Sustainable Development, Utrecht University, Utrecht, The Netherlands
| | - Xavier Capet
- grid.462844.80000 0001 2308 1657Sorbonne Université, CNRS, IRD, MNHN, Laboratoire d’Océanographie et du Climat: Expérimentations et Approches Numériques (LOCEAN-IPSL), Paris, France
| | - Cedric Cotté
- grid.462844.80000 0001 2308 1657Sorbonne Université, CNRS, IRD, MNHN, Laboratoire d’Océanographie et du Climat: Expérimentations et Approches Numériques (LOCEAN-IPSL), Paris, France
| | - Yves Cherel
- grid.452338.b0000 0004 0638 6741Centre d’Etudes Biologiques de Chizé (CEBC), UMR 7372 du CNRS-La Rochelle Université, 79360 Villiers-en-Bois, France
| | - Francesco D’Ovidio
- grid.462844.80000 0001 2308 1657Sorbonne Université, CNRS, IRD, MNHN, Laboratoire d’Océanographie et du Climat: Expérimentations et Approches Numériques (LOCEAN-IPSL), Paris, France
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28
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Davies TE, Carneiro AP, Tarzia M, Wakefield E, Hennicke JC, Frederiksen M, Hansen ES, Campos B, Hazin C, Lascelles B, Anker‐Nilssen T, Arnardóttir H, Barrett RT, Biscoito M, Bollache L, Boulinier T, Catry P, Ceia FR, Chastel O, Christensen‐Dalsgaard S, Cruz‐Flores M, Danielsen J, Daunt F, Dunn E, Egevang C, Fagundes AI, Fayet AL, Fort J, Furness RW, Gilg O, González‐Solís J, Granadeiro JP, Grémillet D, Guilford T, Hanssen SA, Harris MP, Hedd A, Huffeldt NP, Jessopp M, Kolbeinsson Y, Krietsch J, Lang J, Linnebjerg JF, Lorentsen S, Madeiros J, Magnusdottir E, Mallory ML, McFarlane Tranquilla L, Merkel FR, Militão T, Moe B, Montevecchi WA, Morera‐Pujol V, Mosbech A, Neves V, Newell MA, Olsen B, Paiva VH, Peter H, Petersen A, Phillips RA, Ramírez I, Ramos JA, Ramos R, Ronconi RA, Ryan PG, Schmidt NM, Sigurðsson IA, Sittler B, Steen H, Stenhouse IJ, Strøm H, Systad GHR, Thompson P, Thórarinsson TL, Bemmelen RS, Wanless S, Zino F, Dias MP. Multispecies tracking reveals a major seabird hotspot in the North Atlantic. Conserv Lett 2021. [DOI: 10.1111/conl.12824] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
| | | | | | - Ewan Wakefield
- Institute of Biodiversity Animal Health and Comparative Medicine University of Glasgow Glasgow U.K
| | | | | | | | - Bruna Campos
- EuroNatur Foundation Radolfzell Germany
- Stichting BirdLife Europe Brussels Belgium
| | | | | | | | | | | | | | - Loïc Bollache
- UMR 6249 Chrono‐environnement Université de Bourgogne Franche‐Comté Besançon France
- Groupe de Recherche en Ecologie Arctique Francheville France
| | - Thierry Boulinier
- Centre d'Ecologie Fonctionnelle et Evolutive CNRS ‐ Université de Montpellier ‐ Université Paul‐Valéry Montpellier – EPHE Montpellier France
| | - Paulo Catry
- MARE ‐ Marine and Environmental Sciences Centre ISPA ‐ Instituto Universitário Lisbon Portugal
| | - Filipe R. Ceia
- University of Coimbra, MARE‐Marine and Environmental Sciences Centre, Dep. Life Sciences Coimbra Portugal
| | - Olivier Chastel
- Centre d'Etudes Biologiques de Chizé (CEBC) UMR 7372 CNRS‐La Rochelle Université Villiers‐en‐bois France
| | | | - Marta Cruz‐Flores
- Institut de Recerca de la Biodiversitat (IRBio) and Dept. de Biologia Evolutiva, Ecologia i Ciències Ambientals Universitat de Barcelona Barcelona Spain
| | | | | | | | | | | | | | - Jérôme Fort
- Littoral, Environnement et Sociétés (LIENSs) UMR 7266 CNRS‐La Rochelle Université La Rochelle France
| | - Robert W. Furness
- Institute of Biodiversity Animal Health and Comparative Medicine University of Glasgow Glasgow U.K
| | - Olivier Gilg
- UMR 6249 Chrono‐environnement Université de Bourgogne Franche‐Comté Besançon France
- Groupe de Recherche en Ecologie Arctique Francheville France
| | - Jacob González‐Solís
- Institut de Recerca de la Biodiversitat (IRBio) and Dept. de Biologia Evolutiva, Ecologia i Ciències Ambientals Universitat de Barcelona Barcelona Spain
| | | | - David Grémillet
- Centre d'Etudes Biologiques de Chizé (CEBC) UMR 7372 CNRS‐La Rochelle Université Villiers‐en‐bois France
- FitzPatrick Institute of African Ornithology Rondebosch South Africa
| | | | | | | | - April Hedd
- Wildlife Research Division Environment and Climate Change Mount Pearl NL Canada
| | - Nicholas Per Huffeldt
- Department of Bioscience Aarhus University Roskilde Denmark
- Greenland Institute of Natural Resources Nuuk Greenland
| | - Mark Jessopp
- School of Biological, Earth & Environmental Sciences, Environmental Research Institute University College Cork Ireland
| | | | - Johannes Krietsch
- Friedrich Schiller University, Institute of Ecology and Evolution Jena Germany
- Max Planck Institute for Ornithology Department of Behavioural Ecology and Evolutionary Genetics Seewiesen Germany
| | - Johannes Lang
- Groupe de Recherche en Ecologie Arctique Francheville France
- Justus‐Liebig‐University Giessen, Clinic for Birds, Reptiles, Amphibians and Fish Working Group for Wildlife Research Giessen Germany
| | | | | | - Jeremy Madeiros
- Department of Environment and Natural Resources, Government of Bermuda Paget Bermuda
| | | | | | | | - Flemming R. Merkel
- Department of Bioscience Aarhus University Roskilde Denmark
- Greenland Institute of Natural Resources Nuuk Greenland
| | - Teresa Militão
- Institut de Recerca de la Biodiversitat (IRBio) and Dept. de Biologia Evolutiva, Ecologia i Ciències Ambientals Universitat de Barcelona Barcelona Spain
| | - Børge Moe
- Norwegian Institute for Nature Research Trondheim Norway
| | | | - Virginia Morera‐Pujol
- Institut de Recerca de la Biodiversitat (IRBio) and Dept. de Biologia Evolutiva, Ecologia i Ciències Ambientals Universitat de Barcelona Barcelona Spain
| | - Anders Mosbech
- Department of Bioscience Aarhus University Roskilde Denmark
| | - Verónica Neves
- MARE – Marine and Environmental Sciences Centre, IMAR & Okeanos Horta Portugal
| | | | - Bergur Olsen
- Faroe Marine Research Institute Tórshavn Faroe Islands
| | - Vitor H. Paiva
- University of Coimbra, MARE‐Marine and Environmental Sciences Centre, Dep. Life Sciences Coimbra Portugal
| | - Hans‐Ulrich Peter
- Friedrich Schiller University, Institute of Ecology and Evolution Jena Germany
| | | | | | | | - Jaime A. Ramos
- University of Coimbra, MARE‐Marine and Environmental Sciences Centre, Dep. Life Sciences Coimbra Portugal
| | - Raül Ramos
- Institut de Recerca de la Biodiversitat (IRBio) and Dept. de Biologia Evolutiva, Ecologia i Ciències Ambientals Universitat de Barcelona Barcelona Spain
| | - Robert A. Ronconi
- Canadian Wildlife Service, Environment and Climate Change Canada Dartmouth NS Canada
| | - Peter G. Ryan
- FitzPatrick Institute of African Ornithology Rondebosch South Africa
| | | | | | - Benoît Sittler
- Groupe de Recherche en Ecologie Arctique Francheville France
- University of Freiburg Freiburg Germany
| | | | | | | | | | - Paul Thompson
- Lighthouse Field Station, School of Biological Sciences University of Aberdeen Cromarty U.K
| | - Thorkell L. Thórarinsson
- Northeast Iceland Nature Research Centre Húsavík Iceland
- Icelandic Institute of Natural History Garðabær Iceland
| | | | | | | | - Maria P. Dias
- BirdLife International Cambridge U.K
- MARE ‐ Marine and Environmental Sciences Centre ISPA ‐ Instituto Universitário Lisbon Portugal
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29
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Pezzi LP, de Souza RB, Santini MF, Miller AJ, Carvalho JT, Parise CK, Quadro MF, Rosa EB, Justino F, Sutil UA, Cabrera MJ, Babanin AV, Voermans J, Nascimento EL, Alves RCM, Munchow GB, Rubert J. Oceanic eddy-induced modifications to air-sea heat and CO 2 fluxes in the Brazil-Malvinas Confluence. Sci Rep 2021; 11:10648. [PMID: 34017014 PMCID: PMC8137957 DOI: 10.1038/s41598-021-89985-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 04/26/2021] [Indexed: 11/09/2022] Open
Abstract
Sea surface temperature (SST) anomalies caused by a warm core eddy (WCE) in the Southwestern Atlantic Ocean (SWA) rendered a crucial influence on modifying the marine atmospheric boundary layer (MABL). During the first cruise to support the Antarctic Modeling and Observation System (ATMOS) project, a WCE that was shed from the Brazil Current was sampled. Apart from traditional meteorological measurements, we used the Eddy Covariance method to directly measure the ocean–atmosphere sensible heat, latent heat, momentum, and carbon dioxide (CO2) fluxes. The mechanisms of pressure adjustment and vertical mixing that can make the MABL unstable were both identified. The WCE also acted to increase the surface winds and heat fluxes from the ocean to the atmosphere. Oceanic regions at middle and high latitudes are expected to absorb atmospheric CO2, and are thereby considered as sinks, due to their cold waters. Instead, the presence of this WCE in midlatitudes, surrounded by predominantly cold waters, caused the ocean to locally act as a CO2 source. The contribution to the atmosphere was estimated as 0.3 ± 0.04 mmol m−2 day−1, averaged over the sampling period. The CO2 transfer velocity coefficient (K) was determined using a quadratic fit and showed an adequate representation of ocean–atmosphere fluxes. The ocean–atmosphere CO2, momentum, and heat fluxes were each closely correlated with the SST. The increase of SST inside the WCE clearly resulted in larger magnitudes of all of the ocean–atmosphere fluxes studied here. This study adds to our understanding of how oceanic mesoscale structures, such as this WCE, affect the overlying atmosphere.
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Affiliation(s)
- Luciano P Pezzi
- Laboratory of Ocean and Atmosphere Studies (LOA), Earth Observation and Geoinformatics Division (OBT), National Institute for Space Research (INPE), São José dos Campos, SP, Brazil.
| | - Ronald B de Souza
- Earth System Numerical Modeling Division, Center for Weather Forecast and Climate Studies (CPTEC), National Institute for Space Research (INPE), Cachoeira Paulista, SP, Brazil
| | - Marcelo F Santini
- Laboratory of Ocean and Atmosphere Studies (LOA), Earth Observation and Geoinformatics Division (OBT), National Institute for Space Research (INPE), São José dos Campos, SP, Brazil
| | - Arthur J Miller
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, USA
| | - Jonas T Carvalho
- Laboratory of Ocean and Atmosphere Studies (LOA), Earth Observation and Geoinformatics Division (OBT), National Institute for Space Research (INPE), São José dos Campos, SP, Brazil
| | | | - Mario F Quadro
- Federal Institute of Education, Science and Technology of Santa Catarina, Florianópolis, SC, Brazil
| | - Eliana B Rosa
- Laboratory of Ocean and Atmosphere Studies (LOA), Earth Observation and Geoinformatics Division (OBT), National Institute for Space Research (INPE), São José dos Campos, SP, Brazil
| | - Flavio Justino
- Agricultural Engineering Department, Federal University of Viçosa, Viçosa, MG, Brazil
| | - Ueslei A Sutil
- Laboratory of Ocean and Atmosphere Studies (LOA), Earth Observation and Geoinformatics Division (OBT), National Institute for Space Research (INPE), São José dos Campos, SP, Brazil
| | - Mylene J Cabrera
- Laboratory of Ocean and Atmosphere Studies (LOA), Earth Observation and Geoinformatics Division (OBT), National Institute for Space Research (INPE), São José dos Campos, SP, Brazil
| | - Alexander V Babanin
- Department of Infrastructure Engineering, University of Melbourne, Victoria, Australia
| | - Joey Voermans
- Department of Infrastructure Engineering, University of Melbourne, Victoria, Australia
| | - Ernani L Nascimento
- Atmospheric Modeling Group (GruMA), Department of Physics, Federal University of Santa Maria, Santa Maria, RS, Brazil
| | - Rita C M Alves
- Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | | | - Joel Rubert
- Southern Space Coordination (COESU), National Institute for Space Research (CRS/INPE) , Santa Maria, RS, Brazil
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30
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Zhang Y, Ryan JP, Hobson BW, Kieft B, Romano A, Barone B, Preston CM, Roman B, Raanan BY, Pargett D, Dugenne M, White AE, Freitas FH, Poulos S, Wilson ST, DeLong EF, Karl DM, Birch JM, Bellingham JG, Scholin CA. A system of coordinated autonomous robots for Lagrangian studies of microbes in the oceanic deep chlorophyll maximum. Sci Robot 2021; 6:6/50/eabb9138. [PMID: 34043577 DOI: 10.1126/scirobotics.abb9138] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 12/14/2020] [Indexed: 12/31/2022]
Abstract
The deep chlorophyll maximum (DCM) layer is an ecologically important feature of the open ocean. The DCM cannot be observed using aerial or satellite remote sensing; thus, in situ observations are essential. Further, understanding the responses of microbes to the environmental processes driving their metabolism and interactions requires observing in a reference frame that moves with a plankton population drifting in ocean currents, i.e., Lagrangian. Here, we report the development and application of a system of coordinated robots for studying planktonic biological communities drifting within the ocean. The presented Lagrangian system uses three coordinated autonomous robotic platforms. The focal platform consists of an autonomous underwater vehicle (AUV) fitted with a robotic water sampler. This platform localizes and drifts within a DCM community, periodically acquiring samples while continuously monitoring the local environment. The second platform is an AUV equipped with environmental sensing and acoustic tracking capabilities. This platform characterizes environmental conditions by tracking the focal platform and vertically profiling in its vicinity. The third platform is an autonomous surface vehicle equipped with satellite communications and subsea acoustic tracking capabilities. While also acoustically tracking the focal platform, this vehicle serves as a communication relay that connects the subsea robot to human operators, thereby providing situational awareness and enabling intervention if needed. Deployed in the North Pacific Ocean within the core of a cyclonic eddy, this coordinated system autonomously captured fundamental characteristics of the in situ DCM microbial community in a manner not possible previously.
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Affiliation(s)
- Yanwu Zhang
- Monterey Bay Aquarium Research Institute, Moss Landing, CA, USA.
| | - John P Ryan
- Monterey Bay Aquarium Research Institute, Moss Landing, CA, USA
| | - Brett W Hobson
- Monterey Bay Aquarium Research Institute, Moss Landing, CA, USA
| | - Brian Kieft
- Monterey Bay Aquarium Research Institute, Moss Landing, CA, USA
| | - Anna Romano
- University of Hawai'i at Mānoa, Honolulu, HI, USA
| | | | | | - Brent Roman
- Monterey Bay Aquarium Research Institute, Moss Landing, CA, USA
| | - Ben-Yair Raanan
- Monterey Bay Aquarium Research Institute, Moss Landing, CA, USA
| | - Douglas Pargett
- Monterey Bay Aquarium Research Institute, Moss Landing, CA, USA
| | | | | | | | - Steve Poulos
- University of Hawai'i at Mānoa, Honolulu, HI, USA
| | | | | | - David M Karl
- University of Hawai'i at Mānoa, Honolulu, HI, USA
| | - James M Birch
- Monterey Bay Aquarium Research Institute, Moss Landing, CA, USA
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31
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Lünsmann BJ, Kantz H. On star-convex volumes in 2-D hydrodynamical flows and their relevance for coherent transport. CHAOS (WOODBURY, N.Y.) 2020; 30:123147. [PMID: 33380034 DOI: 10.1063/5.0028100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 11/27/2020] [Indexed: 06/12/2023]
Abstract
Oceanic surface flows are dominated by finite-time mesoscale structures that separate two-dimensional flows into volumes of qualitatively different dynamical behavior. Among these, the transport boundaries around eddies are of particular interest since the enclosed volumes show a notable stability with respect to filamentation while being transported over significant distances with consequences for a multitude of different oceanic phenomena. In this paper, we present a novel method to analyze coherent transport in oceanic flows. The presented approach is purely based on convexity and aims to uncover maximal persistently star-convex (MPSC) volumes, volumes that remain star-convex with respect to a chosen reference point during a predefined time window. Since these volumes do not generate filaments, they constitute a sub-class of finite-time coherent volumes. The new perspective yields definitions for filaments, which enables the study of MPSC volume formation and dissipation. We discuss the underlying theory and present an algorithm, the material star-convex structure search, that yields comprehensible and intuitive results. In addition, we apply our method to different velocity fields and illustrate the usefulness of the method for interdisciplinary research by studying the generation of filaments in a real-world example.
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Affiliation(s)
- Benedict J Lünsmann
- Max Planck Institute for the Physics of Complex Systems (MPIPKS), 01187 Dresden, Germany
| | - Holger Kantz
- Max Planck Institute for the Physics of Complex Systems (MPIPKS), 01187 Dresden, Germany
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32
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Abstract
Recent studies demonstrate that energetic sub-mesoscale fronts (10–50 km width) extend in the ocean interior, driving large vertical velocities and associated fluxes. However, diagnosing the dynamics of these deep-reaching fronts from in situ observations remains challenging because of the lack of information on the 3-D structure of the horizontal velocity. Here, a realistic numerical simulation in the Antarctic Circumpolar Current (ACC) is used to study the dynamics of submesocale fronts in relation to velocity gradients, responsible for the formation of these fronts. Results highlight that the stirring properties of the flow at depth, which are related to the velocity gradients, can be inferred from finite-size Lyapunov exponent (FSLE) at the surface. Satellite altimetry observations of FSLE and velocity gradients are then used in combination with recent in situ observations collected by an elephant seal in the ACC to reconstruct frontal dynamics and their associated vertical velocities down to 500 m. The approach proposed here is well suited for the analysis of sub-mesoscale-resolving datasets and the design of future sub-mesoscale field campaigns.
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Monitoring the Influence of the Mesoscale Ocean Dynamics on Phytoplanktonic Plumes around the Marquesas Islands Using Multi-Satellite Missions. REMOTE SENSING 2020. [DOI: 10.3390/rs12162520] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The Marquesas islands are a place of strong phytoplanktonic enhancement, whose original mechanisms have not been explained yet. Several mechanisms such as current−bathymetry interactions or island run-off can fertilize waters in the immediate vicinity or downstream of the islands, allowing phytoplankton enhancement. Here, we took the opportunity of an oceanographic cruise carried out at the end of 2018, to combine in situ and satellite observations to investigate two phytoplanktonic blooms occurring north and south of the archipelago. First, Lagrangian diagnostics show that both chlorophyll-a concentrations (Chl) plumes are advected from the islands. Second, the use of Finite-size Lyaponov Exponent and frontogenesis diagnostics reveal how the Chl plumes are shaped by the passage of a mesoscale cyclonic eddy in the south and by a converging front and finer-scale dynamic activity in the north. Our results based on these observations provide clues to the hypothesis of a fertilization from the islands themselves allowing phytoplankton to thrive. They also highlight the role of advection to disperse and shape the Chl plumes in two regions with contrasting dynamical regimes.
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34
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Relative Influence of Environmental Factors on Biodiversity and Behavioural Traits of a Rare Mesopelagic Fish, Trachipterus trachypterus (Gmelin, 1789), in a Continental Shelf Front of the Mediterranean Sea. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2020. [DOI: 10.3390/jmse8080581] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Coastal environments can be influenced by water body masses with particular physical, chemical, and biological properties that create favourable conditions for the development of unique planktonic communities. In this study, we investigated a continental shelf front at Ponza Island (Tyrrhenian Sea) and discussed its diversity and complexity in relation to major environmental parameters. Moon phase and current direction were found to play a significant role in shaping species abundance and behaviour. During in situ observations, we also provided the first data on the behaviour of juveniles of a rare mesopelagic species, Trachipterus trachypterus, suggesting the occurrence of Batesian mimicry.
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35
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Spatio-Temporal Variability of Chlorophyll-A and Environmental Variables in the Panama Bight. REMOTE SENSING 2020. [DOI: 10.3390/rs12132150] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The analysis of synoptic satellite data of total chlorophyll-a (Chl-a) and the environmental drivers that influence nutrient and light availability for phytoplankton growth allows us to understand the spatio-temporal variability of phytoplankton biomass. In the Panama Bight Tropical region (PB; 1–9°N, 79–84°W), the spatial distribution of Chl-a is mostly related to the seasonal wind patterns and the intensity of localized upwelling centers. However, the association between the Chl-a and different physical variables and nutrient availability is still not fully assessed. In this study, we evaluate the relationship between the Chl-a and multiple physical (wind, Ekman pumping, geostrophic circulation, mixed layer depth, sea level anomalies, river discharges, sea surface temperature, and photosynthetically available radiation) and chemical (nutrients) drivers in order to explain the spatio-temporal Chl-a variability in the PB. We used satellite data of Chl-a and physical variables, and a re-analysis of a biogeochemical product for nutrients (2002–2016). Our results show that at the regional scale, the Chl-a varies seasonally in response to the wind forcing and sea surface temperature. However, in the coastal areas (mainly Gulf of Panama and off central-southern Colombia), the maximum non-seasonal Chl-a values are found in association with the availability of nutrients by river discharges, localized upwelling centers and the geostrophic circulation field. From this study, we infer that the interplay among these physical-chemical drivers is crucial for supporting the phytoplankton growth and the high biodiversity of the PB region.
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36
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Villa Martín P, Buček A, Bourguignon T, Pigolotti S. Ocean currents promote rare species diversity in protists. SCIENCE ADVANCES 2020; 6:eaaz9037. [PMID: 32832617 PMCID: PMC7439499 DOI: 10.1126/sciadv.aaz9037] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 05/29/2020] [Indexed: 05/23/2023]
Abstract
Oceans host communities of plankton composed of relatively few abundant species and many rare species. The number of rare protist species in these communities, as estimated in metagenomic studies, decays as a steep power law of their abundance. The ecological factors at the origin of this pattern remain elusive. We propose that chaotic advection by oceanic currents affects biodiversity patterns of rare species. To test this hypothesis, we introduce a spatially explicit coalescence model that reconstructs the species diversity of a sample of water. Our model predicts, in the presence of chaotic advection, a steeper power law decay of the species abundance distribution and a steeper increase of the number of observed species with sample size. A comparison of metagenomic studies of planktonic protist communities in oceans and in lakes quantitatively confirms our prediction. Our results support that oceanic currents positively affect the diversity of rare aquatic microbes.
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Affiliation(s)
- Paula Villa Martín
- Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| | - Aleš Buček
- Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| | - Thomas Bourguignon
- Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
- Faculty of Tropical AgriSciences, Czech University of Life Sciences, Kamýcká 129, CZ-165 00 Prague, Czech Republic
| | - Simone Pigolotti
- Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
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37
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Guseva K, Feudel U. Numerical modelling of the effect of intermittent upwelling events on plankton blooms. J R Soc Interface 2020; 17:20190889. [PMID: 32343934 DOI: 10.1098/rsif.2019.0889] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In the marine environment, biological processes are strongly affected by oceanic currents, particularly by eddies (vortices) formed by the hydrodynamic flow field. Employing a kinematic flow field coupled to a population dynamical model for plankton growth, we study the impact of an intermittent upwelling of nutrients on triggering harmful algal blooms (HABs). Though it is widely believed that additional nutrients boost the formation of HABs or algal blooms in general, we show that the response of the plankton to nutrient plumes depends crucially on the mesoscale hydrodynamic flow structure. In general, nutrients can either be quickly washed out from the observation area, or can be captured by the vortices in the flow. The occurrence of either scenario depends on the relation between the time scales of the vortex formation and nutrient upwelling as well as the time instants at which upwelling pulses occur and how long they last. We show that these two scenarios result in very different responses in plankton dynamics which makes it very difficult to predict whether nutrient upwelling will lead to a HAB or not. This may in part explain why observational data are sometimes inconclusive in establishing a connection between upwelling events and plankton blooms.
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Affiliation(s)
- Ksenia Guseva
- Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria.,Theoretical Physics/Complex Systems, ICBM, University of Oldenburg, 26129 Oldenburg, Germany
| | - Ulrike Feudel
- Theoretical Physics/Complex Systems, ICBM, University of Oldenburg, 26129 Oldenburg, Germany
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38
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Abstract
The great spatial and temporal variability, which characterizes the marine environment, requires a huge effort to be observed and studied properly since changes in circulation and mixing processes directly influence the variability of the physical and biogeochemical properties. A multi-platform approach and a collaborative effort, in addition to optimizing both data collection and quality, is needed to bring the scientific community to more efficient monitoring and predicting of the world ocean processes. This Special Issue consists of nine original scientific articles that address oceanic circulation and water mass exchange. Most of them deal with mean circulation, basin and sub-basin-scale flows, mesoscale eddies, and internal processes (e.g., mixing and internal waves) that contribute to the redistribution of oceanic properties and energy within the ocean. One paper deals with numerical modelling application finalized to evaluate the capacity of coastal vegetated areas to mitigate the impact of a tsunami. The study areas in which these topics are developed include both oceanic areas and semi-enclosed seas such as the Mediterranean Sea, the Norwegian Sea and the Fram Strait, the South China Sea, and the Northwest Pacific. Scientific findings presented in this Special Issue highlight how a combination of various modern observation techniques can improve our understanding of the complex physical and biogeochemical processes in the ocean.
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39
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Development of an Image De-Noising Method in Preparation for the Surface Water and Ocean Topography Satellite Mission. REMOTE SENSING 2020. [DOI: 10.3390/rs12040734] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In the near future, the Surface Water Ocean Topography (SWOT) mission will provide images of altimetric data at kilometric resolution. This unprecedented 2-dimensional data structure will allow the estimation of geostrophy-related quantities that are essential for studying the ocean surface dynamics and for data assimilation uses. To estimate these quantities, i.e., to compute spatial derivatives of the Sea Surface Height (SSH) measurements, the uncorrelated, small-scale noise and errors expected to affect the SWOT data must be smoothed out while minimizing the loss of relevant, physical SSH information. This paper introduces a new technique for de-noising the future SWOT SSH images. The de-noising model is formulated as a regularized least-square problem with a Tikhonov regularization based on the first-, second-, and third-order derivatives of SSH. The method is implemented and compared to other, convolution-based filtering methods with boxcar and Gaussian kernels. This is performed using a large set of pseudo-SWOT data generated in the western Mediterranean Sea from a 1/60 ∘ simulation and the SWOT simulator. Based on root mean square error and spectral diagnostics, our de-noising method shows a better performance than the convolution-based methods. We find the optimal parametrization to be when only the second-order SSH derivative is penalized. This de-noising reduces the spatial scale resolved by SWOT by a factor of 2, and at 10 km wavelengths, the noise level is reduced by factors of 10 4 and 10 3 for summer and winter, respectively. This is encouraging for the processing of the future SWOT data.
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40
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Schmid MS, Cowen RK, Robinson K, Luo JY, Briseño-Avena C, Sponaugle S. Prey and predator overlap at the edge of a mesoscale eddy: fine-scale, in-situ distributions to inform our understanding of oceanographic processes. Sci Rep 2020; 10:921. [PMID: 31969621 PMCID: PMC6976709 DOI: 10.1038/s41598-020-57879-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 01/03/2020] [Indexed: 11/09/2022] Open
Abstract
Eddies can enhance primary as well as secondary production, creating a diverse meso- and sub-mesoscale seascape at the eddy front which can affect the aggregation of plankton and particles. Due to the coarse resolution provided by sampling with plankton nets, our knowledge of plankton distributions at these edges is limited. We used a towed, undulating underwater imaging system to investigate the physical and biological drivers of zoo- and ichthyoplankton aggregations at the edge of a decaying mesoscale eddy (ME) in the Straits of Florida. Using a sparse Convolutional Neural Network we identified 132 million images of plankton. Larval fish and Oithona spp. copepod concentrations were significantly higher in the eddy water mass, compared to the Florida Current water mass, only four days before the ME's dissipation. Larval fish and Oithona distributions were tightly coupled, indicating potential predator-prey interactions. Larval fishes are known predators of Oithona, however, Random Forests models showed that Oithona spp. and larval fish concentrations were primarily driven by variables signifying the physical footprint of the ME, such as current speed and direction. These results suggest that eddy-related advection leads to largely passive overlap between predator and prey, a positive, energy-efficient outcome for predators at the expense of prey.
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Affiliation(s)
- Moritz S Schmid
- Hatfield Marine Science Center, Oregon State University, Newport, OR, 97365, USA.
| | - Robert K Cowen
- Hatfield Marine Science Center, Oregon State University, Newport, OR, 97365, USA
| | - Kelly Robinson
- Department of Biology, University of Louisiana at Lafayette, Lafayette, LA, 70503, USA
| | - Jessica Y Luo
- NOAA Geophysical Fluid Dynamics Laboratory, Princeton, NJ, 08540, USA
| | - Christian Briseño-Avena
- Hatfield Marine Science Center, Oregon State University, Newport, OR, 97365, USA.,Department of Environmental and Ocean Sciences, University of San Diego, San Diego, CA, 92122, USA
| | - Su Sponaugle
- Department of Integrative Biology, Hatfield Marine Science Center, Oregon State University, Newport, OR, 97365, USA
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41
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Mojica KDA, Carlson CA, Behrenfeld MJ. Regulation of Low and High Nucleic Acid Fluorescent Heterotrophic Prokaryote Subpopulations and Links to Viral-Induced Mortality Within Natural Prokaryote-Virus Communities. MICROBIAL ECOLOGY 2020; 79:213-230. [PMID: 31161232 DOI: 10.1007/s00248-019-01393-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 05/27/2019] [Indexed: 06/09/2023]
Abstract
Flow cytometric analysis of marine prokaryotes routinely reveals two distinct clusters of heterotrophic cells referred to as high nucleic acid fluorescent (HNA) and low nucleic acid fluorescent (LNA) populations. Evidence suggests that these may represent physiologically and ecologically distinct prokaryote populations. According to the "kill the winner" hypothesis, viral lysis reduces the efficiency of the microbial loop by decreasing the biomass and activity of the most abundant and active members of a population (i.e., competition specialist). Thus, viral-induced mortality may vary according to the physiology of HNA and LNA cells, with implications for the marine carbon cycle. Here, the abundance and production of heterotrophic prokaryotic populations were assessed in the North Atlantic during two phases of the annual plankton cycle and related to bottom-up (i.e., organic carbon variability) and top-down processes (i.e., viral abundance and lytic production). Our results demonstrate that the relative abundance of HNA and LNA heterotrophic cells and heterotrophic prokaryote production vary according to organic carbon variability in the water column, which can be strongly influenced by the physical eddy field (i.e., type of eddy: cyclonic, anticyclonic, or no eddy). In addition, the abundance and lytic production of virus subpopulations were correlated with the cellular production and abundance of heterotrophic HNA and LNA prokaryote communities. Our data suggest group- and activity-specific linkages between hosts and viruses (i.e., HNA-V1 and LNA-V2). Specifically, V1 had a greater contribution to total viral production (i.e., 2.6-fold higher than V2 viruses), similar to their putative host. Finally, we explore potential implications of group- and activity-specific linkages between host and virus groups on the flux of carbon through the microbial food web.
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Affiliation(s)
- Kristina D A Mojica
- Department of Botany and Plant Pathology, Cordley Hall 2082, Oregon State University, Corvallis, OR, 97331-29052, USA.
| | - Craig A Carlson
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, 93106-6250, USA
| | - Mike J Behrenfeld
- Department of Botany and Plant Pathology, Cordley Hall 2082, Oregon State University, Corvallis, OR, 97331-29052, USA
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42
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Le C, Wu S, Hu C, Beck MW, Yang X. Phytoplankton decline in the eastern North Pacific transition zone associated with atmospheric blocking. GLOBAL CHANGE BIOLOGY 2019; 25:3485-3493. [PMID: 31220383 DOI: 10.1111/gcb.14737] [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: 03/26/2019] [Accepted: 05/30/2019] [Indexed: 06/09/2023]
Abstract
Global climate change can significantly influence oceanic phytoplankton dynamics, and thus biogeochemical cycles and marine food webs. However, associative explanations based on the correlation between chlorophyll-a concentration (Chl-a) and climatic indices is inadequate to describe the mechanism of the connection between climate change, large-scale atmospheric dynamics, and phytoplankton variability. Here, by analyzing multiple satellite observations of Chl-a and atmospheric conditions from National Center for Environmental Prediction/National Center for Atmospheric Research reanalysis datasets, we show that high-latitude atmospheric blocking events over Alaska are the primary drivers of the recent decline of Chl-a in the eastern North Pacific transition zone. These blocking events were associated with the persistence of large-scale atmosphere pressure fields that decreased westerly winds and southward Ekman transport over the subarctic ocean gyre. Reduced southward Ekman transport leads to reductions in nutrient availability to phytoplankton in the transition zone. The findings describe a previously unidentified climatic factor that contributed to the recent decline of phytoplankton in this region and propose a mechanism of the top-down teleconnection between the high-latitude atmospheric circulation anomalies and the subtropical oceanic primary productivity. The results also highlight the importance of understanding teleconnection among atmosphere-ocean interactions as a means to anticipate future climate change impacts on oceanic primary production.
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Affiliation(s)
- Chengfeng Le
- Ocean College, Zhejiang University, Hangzhou, China
| | - Shuyu Wu
- Ocean College, Zhejiang University, Hangzhou, China
| | - Chuanmin Hu
- College of Marine Science, University of South Florida, St. Petersburg, FL, USA
| | - Marcus W Beck
- Southern California Coastal Water Research Project, Costa Mesa, CA, USA
| | - Xuchao Yang
- Ocean College, Zhejiang University, Hangzhou, China
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43
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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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44
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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: 26] [Impact Index Per Article: 5.2] [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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45
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Glider observations of interleaving layers beneath the Kuroshio primary velocity core east of Taiwan and analyses of underlying dynamics. Sci Rep 2019; 9:11401. [PMID: 31388070 PMCID: PMC6684527 DOI: 10.1038/s41598-019-47912-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 07/26/2019] [Indexed: 11/11/2022] Open
Abstract
Submesoscale interleaving layers are caused by lateral intrusions of dissimilar water masses in frontal zones, which are significant processes in shaping physical, biogeochemical, and ecological parameters in the ocean. Possible interleaving layers were sometimes observed by ship-based conductivity-temperature-depth (CTD) surveys with coarse spacing between adjacent stations in the Kuroshio region east of Taiwan but have never been examined dynamically. Here we show the characteristics of interleaving layers observed by a Seaglider with two repeated hydrographic surveys along a triangle track east of Taiwan from December 2016 to March 2017. Salinity profiles indicate that prominent interleaving layers appeared in the intermediate layer (approximately 500–800 m) with vertical and horizontal length scales of O(50) m and O(10–100) km, respectively, during our observations. A dipole eddy pair and a relatively large anticyclonic eddy impinged on the Kuroshio during the first and second surveys, respectively, which brought certain impacts on the interleaving motion as the eddy potentially altered the density slope across the Kuroshio. The associated instability analysis and the Turner angle suggest that the double diffusive instability is the primary driving mechanism for the development of interleaving layers.
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46
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Diaz F, Bănaru D, Verley P, Shin YJ. Implementation of an end-to-end model of the Gulf of Lions ecosystem (NW Mediterranean Sea). II. Investigating the effects of high trophic levels on nutrients and plankton dynamics and associated feedbacks. Ecol Modell 2019. [DOI: 10.1016/j.ecolmodel.2019.05.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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47
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Haberlin D, Raine R, McAllen R, Doyle TK. Distinct gelatinous zooplankton communities across a dynamic shelf sea. LIMNOLOGY AND OCEANOGRAPHY 2019; 64:1802-1818. [PMID: 31588149 PMCID: PMC6767432 DOI: 10.1002/lno.11152] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 11/16/2018] [Accepted: 02/04/2019] [Indexed: 05/31/2023]
Abstract
Understanding how gelatinous zooplankton communities are structured by local hydrography and physical forcing has important implications for fisheries and higher trophic predators. Although a large body of research has described how fronts, hydrographic boundaries, and different water masses (e.g., mixed vs. stratified) influence phytoplankton and zooplankton communities, comparatively few studies have investigated their influence on gelatinous zooplankton communities. In July 2015, 49 plankton samples were collected from 50 m depth to the surface, across five transects in the Celtic Sea, of which, four crossed the Celtic Sea Front. Two distinct gelatinous communities were found in this dynamic shelf sea: a cold water community in the cooler mixed water that mainly contained neritic taxa and a warm water community in the warmer stratified water that contained a mixture of neritic and oceanic taxa. The gelatinous biomass was 40% greater in the warm water community (∼ 2 mg C m-3) compared with the cold water community (∼ 1.3 mg C m-3). The warm water community was dominated by Aglantha digitale, Lizzia blondina, and Nanomia bijuga, whereas the cold water community was dominated by Clytia hemisphaerica and ctenophores. Physonect siphonophores contributed > 36% to the gelatinous biomass in the warm water community, and their widespread distribution suggests they are ecologically more important than previously thought. A distinct oceanic influence was also recorded in the wider warm water zooplankton community, accounting for a ∼ 20 mg C m-3 increase in biomass in that region.
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Affiliation(s)
- Damien Haberlin
- The Centre for Marine and Renewable EnergyEnvironmental Research InstituteCorkIreland
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
| | - Robin Raine
- The Ryan InstituteNational University Ireland GalwayGalwayIreland
| | - Rob McAllen
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
| | - Thomas K. Doyle
- The Centre for Marine and Renewable EnergyEnvironmental Research InstituteCorkIreland
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
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48
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Zhang Z, Qiu B, Klein P, Travis S. The influence of geostrophic strain on oceanic ageostrophic motion and surface chlorophyll. Nat Commun 2019; 10:2838. [PMID: 31253812 PMCID: PMC6599054 DOI: 10.1038/s41467-019-10883-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 06/07/2019] [Indexed: 11/15/2022] Open
Abstract
Oceanic submesoscale ageostrophic processes have been progressively recognized as an important upwelling mechanism to close the nutrient budget and sustain the observed primary production of phytoplankton in the euphotic layer. Their relatively small spatio-temporal scales (of 1~10 km and a few days) have hindered a systematic observational quantification of the submesoscale ageostrophic flow variability and its impact on ocean biogeochemistry. By combining surface drifters, satellite altimetry and satellite ocean-color data, we detect that when the strain rate of mesoscale surface geostrophic flow is strong, it favors a higher ageostrophic kinetic energy level and an increase in surface chlorophyll concentration. The strain-induced frontal processes are characterized by a surface chlorophyll increase and secondary ageostrophic upwelling along the light side of the oceanic density front. Further analysis indicates that the balanced ageostrophic motions with longer time scales are more effective in inducing chlorophyll increase than the unbalanced shorter time-scale wave motions. The ocean’s swirling eddies are known to influence primary productivity, yet understanding of these processes has been hampered by a lack of resolution. Here the authors combine in-situ drifter, altimeter-based feature tracking, and satellite chlorophyll data to quantify how phytoplankton respond to surface mesoscale phenomena across the globe.
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Affiliation(s)
- Zhengguang Zhang
- Physical Oceanography Lab, Qingdao Collaborative Innovation Center of Marine Science and Technology, Ocean University of China, Qingdao, China.,Laboratory for Ocean and Climate Dynamics, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Bo Qiu
- Department of Oceanography, University of Hawaii at Manoa, Honolulu, HI, USA.
| | - Patrice Klein
- Laboratoire d'Océanographie Physique et Spatiale, Brest, 29200, France
| | - Seth Travis
- Department of Oceanography, University of Hawaii at Manoa, Honolulu, HI, USA
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49
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Abstract
Oceanic eddies play an important role in global energy and material transport, and contribute greatly to nutrient and phytoplankton distribution. Deep learning is employed to identify oceanic eddies from sea surface height anomalies data. In order to adapt to segmentation problems for multi-scale oceanic eddies, the pyramid scene parsing network (PSPNet), which is able to satisfy the fusion of semantics and details, is applied as the core algorithm in the eddy detection methods. The results of eddies identified from this artificial intelligence (AI) method are well compared with those from a traditional vector geometry-based (VG) method. More oceanic eddies are detected by the AI algorithm than the VG method, especially for small-scale eddies. Therefore, the present study demonstrates that the AI algorithm is applicable of oceanic eddy detection. It is one of the first few of efforts to bridge AI techniques and oceanography research.
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50
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Fossum TO, Fragoso GM, Davies EJ, Ullgren JE, Mendes R, Johnsen G, Ellingsen I, Eidsvik J, Ludvigsen M, Rajan K. Toward adaptive robotic sampling of phytoplankton in the coastal ocean. Sci Robot 2019; 4:4/27/eaav3041. [DOI: 10.1126/scirobotics.aav3041] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 12/20/2018] [Indexed: 11/02/2022]
Affiliation(s)
- Trygve O. Fossum
- Department of Marine Technology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- Centre for Autonomous Marine Operations and Systems (AMOS), Trondheim, Norway
| | | | | | | | - Renato Mendes
- Underwater Systems and Technology Laboratory, Faculty of Engineering, University of Porto, Porto, Portugal
- CIIMAR, University of Porto, Porto, Portugal
- CESAM, Department of Physics, University of Aveiro, Aveiro, Portugal
| | - Geir Johnsen
- Centre for Autonomous Marine Operations and Systems (AMOS), Trondheim, Norway
- Department of Biology, NTNU, Trondheim, Norway
- University Centre in Svalbard (UNIS), Longyearbyen, Norway
| | | | - Jo Eidsvik
- Department of Mathematical Sciences, NTNU, Trondheim, Norway
| | - Martin Ludvigsen
- Department of Marine Technology, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- Centre for Autonomous Marine Operations and Systems (AMOS), Trondheim, Norway
- University Centre in Svalbard (UNIS), Longyearbyen, Norway
| | - Kanna Rajan
- Centre for Autonomous Marine Operations and Systems (AMOS), Trondheim, Norway
- Underwater Systems and Technology Laboratory, Faculty of Engineering, University of Porto, Porto, Portugal
- Department of Engineering Cybernetics, NTNU, Trondheim, Norway
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