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Wei Y, Luan Q, Shan X, Cui H, Qu K, Cui Z, Sun J. Temperature and nutrients drive distinct successions between diatoms and dinoflagellates over the past 40 years: Implications for climate warming and eutrophication. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 931:172997. [PMID: 38714256 DOI: 10.1016/j.scitotenv.2024.172997] [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: 12/10/2023] [Revised: 04/21/2024] [Accepted: 05/02/2024] [Indexed: 05/09/2024]
Abstract
Diatoms and dinoflagellates are two typical functional groups of phytoplankton, playing important roles in ecosystem processes and biogeochemical cycles. Changes in diatoms and dinoflagellates are thought to be one of the possible mechanisms for the increase in harmful algal blooms (HABs), due to changing hydrological conditions associated with climate change and human activities. However, little is known about their ability to adapt to changing ocean environments, thus making it difficult to know whether and how they are adapting. By analyzing a 44-year monitoring dataset in the central Bohai Sea during 1978-2021, we found that the abundance ratio of diatoms to dinoflagellates showed a decreasing trend seasonally and ecologically, indicating that the phytoplankton community underwent distinct successional processes from diatom dominance to diatom-dinoflagellate co-dominance. These processes exhibited varying responses to temperature, nutrient concentrations and ratios, and their interactions, of which temperature primarily drove the seasonal succession whereas nutrients were responsible for the ecological succession. Specifically, diatoms showed a preference for lower temperatures and higher DIP concentrations, and were able to tolerate lower DIN at lower temperatures. In contrast, dinoflagellates tended to prevail at conditions of warming and high N/P ratios. These different traits of diatoms and dinoflagellates reflected the fact that warming as a result of rising temperature and eutrophication as a consequence of nutrient input would favor dinoflagellates over diatoms. Moreover, the increasing dominance of dinoflagellates indicated that dinoflagellate blooms were likely to become more frequent and intense in the central Bohai Sea.
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Affiliation(s)
- Yuqiu Wei
- State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, Shandong, China; Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Qingshan Luan
- State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, Shandong, China; Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Xiujuan Shan
- State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, Shandong, China; Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Hongwu Cui
- State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, Shandong, China; Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Keming Qu
- State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, Shandong, China; Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Zhengguo Cui
- State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, Shandong, China; Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture and Rural Affairs, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China.
| | - Jun Sun
- Institute for Advanced Marine Research, China University of Geosciences, Guangzhou, China.
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Bogumil M, Mittal T, Lithgow-Bertelloni C. The effects of bathymetry on the long-term carbon cycle and CCD. Proc Natl Acad Sci U S A 2024; 121:e2400232121. [PMID: 38748585 PMCID: PMC11126914 DOI: 10.1073/pnas.2400232121] [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: 01/05/2024] [Accepted: 04/03/2024] [Indexed: 05/27/2024] Open
Abstract
The shape of the ocean floor (bathymetry) and the overlaying sediments provide the largest carbon sink throughout Earth's history, supporting ~one to two orders of magnitude more carbon storage than the oceans and atmosphere combined. While accumulation and erosion of these sediments are bathymetry dependent (e.g., due to pressure, temperature, salinity, ion concentration, and available productivity), no systemic study has quantified how global and basin scale bathymetry, controlled by the evolution of tectonics and mantle convection, affects the long-term carbon cycle. We reconstruct bathymetry spanning the last 80 Myr to describe steady-state changes in ocean chemistry within the Earth system model LOSCAR. We find that both bathymetry reconstructions and representative synthetic tests show that ocean alkalinity, calcite saturation state, and the carbonate compensation depth (CCD) are strongly dependent on changes in shallow bathymetry (ocean floor ≤600 m) and on the distribution of the deep marine regions (>1,000 m). Limiting Cenozoic evolution to bathymetry alone leads to predicted CCD variations spanning 500 m, 33 to 50% of the total observed variations in the paleoproxy records. Our results suggest that neglecting bathymetric changes leads to significant misattribution to uncertain carbon cycle parameters (e.g., atmospheric CO2 and water column temperature) and processes (e.g., biological pump efficiency and silicate-carbonate riverine flux). To illustrate this point, we use our updated bathymetry for an Early Paleogene C cycle case study. We obtain carbonate riverine flux estimates that suggest a reversal of the weathering trend with respect to present-day, contrasting with previous studies, but consistent with proxy records and tectonic reconstructions.
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Affiliation(s)
- Matthew Bogumil
- Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, CA90095-1567
| | - Tushar Mittal
- Department of Geosciences, The Pennsylvania State University, University Park, PA16802
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3
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Karthäuser C, Fucile PD, Maas AE, Blanco-Bercial L, Gossner H, Lowenstein DP, Niimi YJ, Van Mooy BAS, Bernhard JM, Buesseler KO, Sievert SM. RotoBOD─Quantifying Oxygen Consumption by Suspended Particles and Organisms. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:8760-8770. [PMID: 38717860 PMCID: PMC11112748 DOI: 10.1021/acs.est.4c03186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2024] [Revised: 04/16/2024] [Accepted: 04/18/2024] [Indexed: 05/22/2024]
Abstract
Sinking or floating is the natural state of planktonic organisms and particles in the ocean. Simulating these conditions is critical when making measurements, such as respirometry, because they allow the natural exchange of substrates and products between sinking particles and water flowing around them and prevent organisms that are accustomed to motion from changing their metabolism. We developed a rotating incubator, the RotoBOD (named after its capability to rotate and determine biological oxygen demand, BOD), that uniquely enables automated oxygen measurements in small volumes while keeping the samples in their natural state of suspension. This allows highly sensitive rate measurements of oxygen utilization and subsequent characterization of single particles or small planktonic organisms, such as copepods, jellyfish, or protists. As this approach is nondestructive, it can be combined with several further measurements during and after the incubation, such as stable isotope additions and molecular analyses. This makes the instrument useful for ecologists, biogeochemists, and potentially other user groups such as aquaculture facilities. Here, we present the technical background of our newly developed apparatus and provide examples of how it can be utilized to determine oxygen production and consumption in small organisms and particles.
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Affiliation(s)
- Clarissa Karthäuser
- Woods
Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, Falmouth, Massachusetts 02543, United States
| | - Paul D. Fucile
- Woods
Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, Falmouth, Massachusetts 02543, United States
| | - Amy E. Maas
- Bermuda
Institute of Ocean Sciences, Arizona State
University, 17 Biological
Station, St. George’s GE01, Bermuda
| | - Leocadio Blanco-Bercial
- Bermuda
Institute of Ocean Sciences, Arizona State
University, 17 Biological
Station, St. George’s GE01, Bermuda
| | - Hannah Gossner
- Bermuda
Institute of Ocean Sciences, Arizona State
University, 17 Biological
Station, St. George’s GE01, Bermuda
| | - Daniel P. Lowenstein
- Woods
Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, Falmouth, Massachusetts 02543, United States
| | - Yuuki J. Niimi
- Bermuda
Institute of Ocean Sciences, Arizona State
University, 17 Biological
Station, St. George’s GE01, Bermuda
| | - Benjamin A. S. Van Mooy
- Woods
Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, Falmouth, Massachusetts 02543, United States
| | - Joan M. Bernhard
- Woods
Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, Falmouth, Massachusetts 02543, United States
| | - Ken O. Buesseler
- Woods
Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, Falmouth, Massachusetts 02543, United States
| | - Stefan M. Sievert
- Woods
Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, Falmouth, Massachusetts 02543, United States
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4
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Franz BA, Cetinić I, Ibrahim A, Sayer AM. Anomalous trends in global ocean carbon concentrations following the 2022 eruptions of Hunga Tonga-Hunga Ha'apai. COMMUNICATIONS EARTH & ENVIRONMENT 2024; 5:247. [PMID: 38736528 PMCID: PMC11087252 DOI: 10.1038/s43247-024-01421-8] [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: 11/22/2023] [Accepted: 04/23/2024] [Indexed: 05/14/2024]
Abstract
We report on observed trend anomalies in climate-relevant global ocean biogeochemical properties, as derived from satellite ocean color measurements, that show a substantial decline in phytoplankton carbon concentrations following eruptions of the submarine volcano Hunga Tonga-Hunga Ha'apai in January 2022. The anomalies are seen in remotely-sensed ocean color data sets from multiple satellite missions, but not in situ observations, thus suggesting that the observed anomalies are a result of ocean color retrieval errors rather than indicators of a major shift in phytoplankton carbon concentrations. The enhanced concentration of aerosols in the stratosphere following the eruptions results in a violation of some fundamental assumptions in the processing algorithms used to obtain marine biogeochemical properties from satellite radiometric observations, and it is demonstrated through radiative transfer simulations that this is the likely cause of the anomalous trends. We note that any future stratospheric aerosol disturbances, either natural or geoengineered, may lead to similar artifacts in satellite ocean color and other remote-sensing measurements of the marine environment, thus confounding our ability to track the impact of such events on ocean ecosystems.
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Affiliation(s)
| | - Ivona Cetinić
- NASA Goddard Space Flight Center, Greenbelt, MD USA
- Morgan State University, Baltimore, MD USA
| | - Amir Ibrahim
- NASA Goddard Space Flight Center, Greenbelt, MD USA
| | - Andrew M. Sayer
- NASA Goddard Space Flight Center, Greenbelt, MD USA
- University of Maryland Baltimore County, Baltimore, MD USA
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5
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Freilich MA, Poirier C, Dever M, Alou-Font E, Allen J, Cabornero A, Sudek L, Choi CJ, Ruiz S, Pascual A, Farrar JT, Johnston TMS, D’Asaro EA, Worden AZ, Mahadevan A. 3D intrusions transport active surface microbial assemblages to the dark ocean. Proc Natl Acad Sci U S A 2024; 121:e2319937121. [PMID: 38696469 PMCID: PMC11087786 DOI: 10.1073/pnas.2319937121] [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: 11/14/2023] [Accepted: 03/18/2024] [Indexed: 05/04/2024] Open
Abstract
Subtropical oceans contribute significantly to global primary production, but the fate of the picophytoplankton that dominate in these low-nutrient regions is poorly understood. Working in the subtropical Mediterranean, we demonstrate that subduction of water at ocean fronts generates 3D intrusions with uncharacteristically high carbon, chlorophyll, and oxygen that extend below the sunlit photic zone into the dark ocean. These contain fresh picophytoplankton assemblages that resemble the photic-zone regions where the water originated. Intrusions propagate depth-dependent seasonal variations in microbial assemblages into the ocean interior. Strikingly, the intrusions included dominant biomass contributions from nonphotosynthetic bacteria and enrichment of enigmatic heterotrophic bacterial lineages. Thus, the intrusions not only deliver material that differs in composition and nutritional character from sinking detrital particles, but also drive shifts in bacterial community composition, organic matter processing, and interactions between surface and deep communities. Modeling efforts paired with global observations demonstrate that subduction can flux similar magnitudes of particulate organic carbon as sinking export, but is not accounted for in current export estimates and carbon cycle models. Intrusions formed by subduction are a particularly important mechanism for enhancing connectivity between surface and upper mesopelagic ecosystems in stratified subtropical ocean environments that are expanding due to the warming climate.
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Affiliation(s)
- Mara A. Freilich
- Massachusetts Institute of Technology-Wood Hole Oceanographic Institution Joint Program in Oceanography, Woods Hole, MA02543
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA92093
- Department of Earth, Environmental, and Planetary Sciences, Brown University, Providence, RI02912
- Division of Applied Mathematics, Brown University, Providence, RI02912
| | - Camille Poirier
- GEOMAR—Helmholtz Centre for Ocean Research, Kiel24105, Germany
| | - Mathieu Dever
- Department of Physical Oceanography, Woods Hole Oceanographic Institution, Woods Hole, MA02543
| | - Eva Alou-Font
- Sistema de Observación y Predicción Costero de las Illes Balears (SOCIB), Palma de Mallorca 07121, Spain
| | - John Allen
- Sistema de Observación y Predicción Costero de las Illes Balears (SOCIB), Palma de Mallorca 07121, Spain
| | - Andrea Cabornero
- Sistema de Observación y Predicción Costero de las Illes Balears (SOCIB), Palma de Mallorca 07121, Spain
| | - Lisa Sudek
- Physical & Biological Sciences Division, University of California, Santa Cruz, CA95064
| | - Chang Jae Choi
- GEOMAR—Helmholtz Centre for Ocean Research, Kiel24105, Germany
| | - Simón Ruiz
- Instituto Mediterraneo de Estudios Avanzados (IMEDEA), Esporles07190, Spain
| | - Ananda Pascual
- Instituto Mediterraneo de Estudios Avanzados (IMEDEA), Esporles07190, Spain
| | - J. Thomas Farrar
- Department of Physical Oceanography, Woods Hole Oceanographic Institution, Woods Hole, MA02543
| | - T. M. Shaun Johnston
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA92093
| | - Eric A. D’Asaro
- Applied Physics Lab, University of Washington, Seattle, WA98105
| | - Alexandra Z. Worden
- GEOMAR—Helmholtz Centre for Ocean Research, Kiel24105, Germany
- Physical & Biological Sciences Division, University of California, Santa Cruz, CA95064
- Marine Biological Laboratory, Woods Hole, MA02543
| | - Amala Mahadevan
- Department of Physical Oceanography, Woods Hole Oceanographic Institution, Woods Hole, MA02543
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6
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Guo S, Sun X, Zhang J, Yao Q, Wei C, Wang F. Unveiling the evolution of phytoplankton communities: Decades-long insights into the southern Yellow Sea, China (1959-2023). MARINE POLLUTION BULLETIN 2024; 201:116179. [PMID: 38394795 DOI: 10.1016/j.marpolbul.2024.116179] [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: 12/26/2023] [Revised: 02/11/2024] [Accepted: 02/16/2024] [Indexed: 02/25/2024]
Abstract
We obtained historical and observational data on phytoplankton communities from 1959 to 2023 to explore the responses of the phytoplankton community structure to long-term environmental changes in the southern Yellow Sea (SYS), China. The results revealed a decrease in the proportions of diatom cell abundance within the phytoplankton community by 8 %, accompanied by a corresponding increase in that of dinoflagellates. Dominant phytoplankton species were mainly chain-forming diatoms before 2000, and large dinoflagellate species from the genera Tripos and Noctiluca increased their dominance after 2000. Warm-water phytoplankton species have increased in dominance over the study period. Correlation analysis revealed that the ocean warming and alterations in nutrient structure (N/P and Si/N ratios) were mostly responsible for the long-term evolution trend, and these changes may result in an increase in dinoflagellate harmful algal blooms, reduced efficiency of the biological carbon pump, and heightened hypoxia in the future, which should draw our attention.
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Affiliation(s)
- Shujin Guo
- Jiaozhou Bay National Marine Ecosystem Research Station, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, PR China; Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao 266237, PR China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, PR China
| | - Xiaoxia Sun
- Jiaozhou Bay National Marine Ecosystem Research Station, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, PR China; Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao 266237, PR China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
| | - Jian Zhang
- National Marine Data and Information Service, Tianjin 300171, PR China
| | - Qingzhen Yao
- Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, PR China
| | - Chuanjie Wei
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, PR China; Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, PR China
| | - Feng Wang
- Jiaozhou Bay National Marine Ecosystem Research Station, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
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7
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Lomas MW, Neeley AR, Vandermeulen R, Mannino A, Thomas C, Novak MG, Freeman SA. Phytoplankton optical fingerprint libraries for development of phytoplankton ocean color satellite products. Sci Data 2024; 11:168. [PMID: 38310126 DOI: 10.1038/s41597-024-03001-z] [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: 10/06/2023] [Accepted: 01/25/2024] [Indexed: 02/05/2024] Open
Abstract
Phytoplankton respond to physical and hydrographic forcing on time and space scales up to and including those relevant to climate change. Quantifying changes in phytoplankton communities over these scales is essential for predicting ocean food resources, occurrences of harmful algal blooms, and carbon and other elemental cycles, among other predictions. However, one of the best tools for quantifying phytoplankton communities across relevant time and space scales, ocean color sensors, is constrained by its own spectral capabilities and availability of adequately vetted and relevant optical models. To address this later shortcoming, greater than fifty strains of phytoplankton, from a range of taxonomic lineages, geographic locations, and time in culture, alone and in mixtures, were grown to exponential and/or stationary phase for determination of hyperspectral UV-VIS absorption coefficients, multi-angle and multi-spectral backscatter coefficients, volume scattering functions, particle size distributions, pigment content, and fluorescence. The aim of this publication is to share these measurements to expedite their utilization in the development of new optical models for the next generation of ocean color satellites.
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Affiliation(s)
- Michael W Lomas
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, 04544, USA.
| | - Aimee R Neeley
- NASA Goddard Space Flight Center/Science Systems and Applications Inc., Greenbelt, Maryland, 20771, USA
| | - Ryan Vandermeulen
- NASA Goddard Space Flight Center/Science Systems and Applications Inc., Greenbelt, Maryland, 20771, USA
- NOAA National Marine Fisheries Service, Silver Spring, Maryland, 20910, USA
| | - Antonio Mannino
- NASA Goddard Space Flight Center, Greenbelt, Maryland, 20771, USA
| | - Crystal Thomas
- NASA Goddard Space Flight Center/Science Systems and Applications Inc., Greenbelt, Maryland, 20771, USA
| | - Michael G Novak
- NASA Goddard Space Flight Center/Science Systems and Applications Inc., Greenbelt, Maryland, 20771, USA
- Institute of Carbon Cycles, Helmholtz-Zentrum Hereon, Geesthacht, Germany
| | - Scott A Freeman
- NASA Goddard Space Flight Center/Science Systems and Applications Inc., Greenbelt, Maryland, 20771, USA
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Burd AB. Modeling the Vertical Flux of Organic Carbon in the Global Ocean. ANNUAL REVIEW OF MARINE SCIENCE 2024; 16:135-161. [PMID: 37418834 DOI: 10.1146/annurev-marine-022123-102516] [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: 07/09/2023]
Abstract
The oceans play a fundamental role in the global carbon cycle, providing a sink for atmospheric carbon. Key to this role is the vertical transport of organic carbon from the surface to the deep ocean. This transport is a product of a diverse range of physical and biogeochemical processes that determine the formation and fate of this material, and in particular how much carbon is sequestered in the deep ocean. Models can be used to both diagnose biogeochemical processes and predict how the various processes will change in the future. Global biogeochemical models use simplified representations of food webs and processes but are converging on values for the export of organic carbon from the surface ocean. Other models concentrate on understanding specific processes and can be used to develop parameterizations for global models. Model development is continuing by adding representations and parameterizations of higher trophic levels and mesopelagic processes, and these are expected to improve model performance.
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Affiliation(s)
- Adrian B Burd
- Department of Marine Sciences, University of Georgia, Athens, Georgia, USA;
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9
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Gray AR. The Four-Dimensional Carbon Cycle of the Southern Ocean. ANNUAL REVIEW OF MARINE SCIENCE 2024; 16:163-190. [PMID: 37738480 DOI: 10.1146/annurev-marine-041923-104057] [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: 09/24/2023]
Abstract
The Southern Ocean plays a fundamental role in the global carbon cycle, dominating the oceanic uptake of heat and carbon added by anthropogenic activities and modulating atmospheric carbon concentrations in past, present, and future climates. However, the remote and extreme conditions found there make the Southern Ocean perpetually one of the most difficult places on the planet to observe and to model, resulting in significant and persistent uncertainties in our knowledge of the oceanic carbon cycle there. The flow of carbon in the Southern Ocean is traditionally understood using a zonal mean framework, in which the meridional overturning circulation drives the latitudinal variability observed in both air-sea flux and interior ocean carbon concentration. However, recent advances, based largely on expanded observation and modeling capabilities in the region, reveal the importance of processes acting at smaller scales, including basin-scale zonal asymmetries in mixed-layer depth, mesoscale eddies, and high-frequency atmospheric variability. Assessing the current state of knowledge and remaining gaps emphasizes the need to move beyond the zonal mean picture and embrace a four-dimensional understanding of the carbon cycle in the Southern Ocean.
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Affiliation(s)
- Alison R Gray
- School of Oceanography, University of Washington, Seattle, Washington, USA;
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10
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Roca-Martí M, Puigcorbé V. Combined Use of Short-Lived Radionuclides ( 234Th and 210Po) as Tracers of Sinking Particles in the Ocean. ANNUAL REVIEW OF MARINE SCIENCE 2024; 16:551-575. [PMID: 37708423 DOI: 10.1146/annurev-marine-041923-013807] [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: 09/16/2023]
Abstract
Radionuclides can provide key information on the temporal dimension of environmental processes, given their well-known rates of radioactive decay and production. Naturally occurring radionuclides, such as 234Th and 210Po, have been used as powerful particle tracers in the marine environment to study particle cycling and vertical export. Since their application to quantify the magnitude of particulate organic carbon (POC) export in the 1990s, 234Th and, to a lesser extent, 210Po have been widely used to characterize the magnitude of the biological carbon pump (BCP). Combining both radionuclides, with their different half-lives, biogeochemical behaviors, and input sources to the ocean, can help to better constrain POC export and capture BCP dynamics that would be missed by a single tracer. Here, we review the studies that have simultaneously used 234Th and 210Po as tracers of POC export, emphasizing what can be learned from their joint application, and provide recommendations and future directions.
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Affiliation(s)
- Montserrat Roca-Martí
- Institut de Ciència i Tecnologia Ambientals (ICTA-UAB), Universitat Autònoma de Barcelona, Cerdanyola del Vallès, Spain;
| | - Viena Puigcorbé
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar (ICM-CSIC), Barcelona, Spain;
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11
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van der Mheen M, Wernberg T, Pattiaratchi C, Pessarrodona A, Janekovic I, Simpkins T, Hovey R, Filbee-Dexter K. Substantial kelp detritus exported beyond the continental shelf by dense shelf water transport. Sci Rep 2024; 14:839. [PMID: 38191572 PMCID: PMC10774291 DOI: 10.1038/s41598-023-51003-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 12/29/2023] [Indexed: 01/10/2024] Open
Abstract
Kelp forests may contribute substantially to ocean carbon sequestration, mainly through transporting kelp carbon away from the coast and into the deep sea. However, it is not clear if and how kelp detritus is transported across the continental shelf. Dense shelf water transport (DSWT) is associated with offshore flows along the seabed and provides an effective mechanism for cross-shelf transport. In this study, we determine how effective DSWT is in exporting kelp detritus beyond the continental shelf edge, by considering the transport of simulated sinking kelp detritus from a region of Australia's Great Southern Reef. We show that DSWT is the main mechanism that transports simulated kelp detritus past the continental shelf edge, and that export is negligible when DSWT does not occur. We find that 51% per year of simulated kelp detritus is transported past the continental shelf edge, or 17-29% when accounting for decomposition while in transit across the shelf. This is substantially more than initial global estimates. Because DSWT occurs in many mid-latitude locations around the world, where kelp forests are also most productive, export of kelp carbon from the coast could be considerably larger than initially expected.
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Affiliation(s)
- Mirjam van der Mheen
- School of Biological Sciences and UWA Oceans Institute, University of Western Australia, Perth, WA, Australia.
| | - Thomas Wernberg
- School of Biological Sciences and UWA Oceans Institute, University of Western Australia, Perth, WA, Australia
- Institute of Marine Research, Nye Flødevigveien 20, His, 4817, Norway
| | - Charitha Pattiaratchi
- Oceans Graduate School and UWA Oceans Institute, University of Western Australia, Perth, WA, Australia
| | - Albert Pessarrodona
- School of Biological Sciences and UWA Oceans Institute, University of Western Australia, Perth, WA, Australia
| | - Ivica Janekovic
- Oceans Graduate School and UWA Oceans Institute, University of Western Australia, Perth, WA, Australia
| | - Taylor Simpkins
- School of Biological Sciences and UWA Oceans Institute, University of Western Australia, Perth, WA, Australia
| | - Renae Hovey
- School of Biological Sciences and UWA Oceans Institute, University of Western Australia, Perth, WA, Australia
| | - Karen Filbee-Dexter
- School of Biological Sciences and UWA Oceans Institute, University of Western Australia, Perth, WA, Australia
- Institute of Marine Research, Nye Flødevigveien 20, His, 4817, Norway
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Anderson SR, Blanco-Bercial L, Carlson CA, Harvey EL. Role of Syndiniales parasites in depth-specific networks and carbon flux in the oligotrophic ocean. ISME COMMUNICATIONS 2024; 4:ycae014. [PMID: 38419659 PMCID: PMC10900894 DOI: 10.1093/ismeco/ycae014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 01/18/2024] [Accepted: 01/18/2024] [Indexed: 03/02/2024]
Abstract
Microbial associations that result in phytoplankton mortality are important for carbon transport in the ocean. This includes parasitism, which in microbial food webs is dominated by the marine alveolate group, Syndiniales. Parasites are expected to contribute to carbon recycling via host lysis; however, knowledge on host dynamics and correlation to carbon export remain unclear and limit the inclusion of parasitism in biogeochemical models. We analyzed a 4-year 18S rRNA gene metabarcoding dataset (2016-19), performing network analysis for 12 discrete depths (1-1000 m) to determine Syndiniales-host associations in the seasonally oligotrophic Sargasso Sea. Analogous water column and sediment trap data were included to define environmental drivers of Syndiniales and their correlation with particulate carbon flux (150 m). Syndiniales accounted for 48-74% of network edges, most often associated with Dinophyceae and Arthropoda (mainly copepods) at the surface and Rhizaria (Polycystinea, Acantharea, and RAD-B) in the aphotic zone. Syndiniales were the only eukaryote group to be significantly (and negatively) correlated with particulate carbon flux, indicating their contribution to flux attenuation via remineralization. Examination of Syndiniales amplicons revealed a range of depth patterns, including specific ecological niches and vertical connection among a subset (19%) of the community, the latter implying sinking of parasites (infected hosts or spores) on particles. Our findings elevate the critical role of Syndiniales in marine microbial systems and reveal their potential use as biomarkers for carbon export.
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Affiliation(s)
- Sean R Anderson
- Department of Biological Sciences, University of New Hampshire, Durham, NH 03824, United States
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, Falmouth, MA 02543, United States
| | | | - Craig A Carlson
- Department of Ecology, Evolution and Marine Biology and the Marine Science Institute, University of California, Santa Barbara, CA 93106, United States
| | - Elizabeth L Harvey
- Department of Biological Sciences, University of New Hampshire, Durham, NH 03824, United States
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13
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Wang WL, Fu W, Le Moigne FAC, Letscher RT, Liu Y, Tang JM, Primeau FW. Biological carbon pump estimate based on multidecadal hydrographic data. Nature 2023; 624:579-585. [PMID: 38057667 PMCID: PMC10733149 DOI: 10.1038/s41586-023-06772-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 10/20/2023] [Indexed: 12/08/2023]
Abstract
The transfer of photosynthetically produced organic carbon from surface to mesopelagic waters draws carbon dioxide from the atmosphere1. However, current observation-based estimates disagree on the strength of this biological carbon pump (BCP)2. Earth system models (ESMs) also exhibit a large spread of BCP estimates, indicating limited representations of the known carbon export pathways3. Here we use several decades of hydrographic observations to produce a top-down estimate of the strength of the BCP with an inverse biogeochemical model that implicitly accounts for all known export pathways. Our estimate of total organic carbon (TOC) export at 73.4 m (model euphotic zone depth) is 15.00 ± 1.12 Pg C year-1, with only two-thirds reaching 100 m depth owing to rapid remineralization of organic matter in the upper water column. Partitioned by sequestration time below the euphotic zone, τ, the globally integrated organic carbon production rate with τ > 3 months is 11.09 ± 1.02 Pg C year-1, dropping to 8.25 ± 0.30 Pg C year-1 for τ > 1 year, with 81% contributed by the non-advective-diffusive vertical flux owing to sinking particles and vertically migrating zooplankton. Nevertheless, export of organic carbon by mixing and other fluid transport of dissolved matter and suspended particles remains regionally important for meeting the respiratory carbon demand. Furthermore, the temperature dependence of the sequestration efficiency inferred from our inversion suggests that future global warming may intensify the recycling of organic matter in the upper ocean, potentially weakening the BCP.
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Affiliation(s)
- Wei-Lei Wang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China.
| | - Weiwei Fu
- Department of Earth System Science, University of California, Irvine, Irvine, CA, USA
- Department of Atmospheric and Oceanic Science, Fudan University, Shanghai, China
| | | | - Robert T Letscher
- Earth Sciences and Ocean Process Analysis Laboratory, University of New Hampshire, Durham, NH, USA
| | - Yi Liu
- Department of Earth System Science, University of California, Irvine, Irvine, CA, USA
- Department of Geosciences, Princeton University, Princeton, NJ, USA
| | - Jin-Ming Tang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - François W Primeau
- Department of Earth System Science, University of California, Irvine, Irvine, CA, USA.
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14
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Pessarrodona A, Franco-Santos RM, Wright LS, Vanderklift MA, Howard J, Pidgeon E, Wernberg T, Filbee-Dexter K. Carbon sequestration and climate change mitigation using macroalgae: a state of knowledge review. Biol Rev Camb Philos Soc 2023; 98:1945-1971. [PMID: 37437379 DOI: 10.1111/brv.12990] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 06/05/2023] [Accepted: 06/07/2023] [Indexed: 07/14/2023]
Abstract
The conservation, restoration, and improved management of terrestrial forests significantly contributes to mitigate climate change and its impacts, as well as providing numerous co-benefits. The pressing need to reduce emissions and increase carbon removal from the atmosphere is now also leading to the development of natural climate solutions in the ocean. Interest in the carbon sequestration potential of underwater macroalgal forests is growing rapidly among policy, conservation, and corporate sectors. Yet, our understanding of whether carbon sequestration from macroalgal forests can lead to tangible climate change mitigation remains severely limited, hampering their inclusion in international policy or carbon finance frameworks. Here, we examine the results of over 180 publications to synthesise evidence regarding macroalgal forest carbon sequestration potential. We show that research efforts on macroalgae carbon sequestration are heavily skewed towards particulate organic carbon (POC) pathways (77% of data publications), and that carbon fixation is the most studied flux (55%). Fluxes leading directly to carbon sequestration (e.g. carbon export or burial in marine sediments) remain poorly resolved, likely hindering regional or country-level assessments of carbon sequestration potential, which are only available from 17 of the 150 countries where macroalgal forests occur. To solve this issue, we present a framework to categorize coastlines according to their carbon sequestration potential. Finally, we review the multiple avenues through which this sequestration can translate into climate change mitigation capacity, which largely depends on whether management interventions can increase carbon removal above a natural baseline or avoid further carbon emissions. We find that conservation, restoration and afforestation interventions on macroalgal forests can potentially lead to carbon removal in the order of 10's of Tg C globally. Although this is lower than current estimates of natural sequestration value of all macroalgal habitats (61-268 Tg C year-1 ), it suggests that macroalgal forests could add to the total mitigation potential of coastal blue carbon ecosystems, and offer valuable mitigation opportunities in polar and temperate areas where blue carbon mitigation is currently low. Operationalizing that potential will necessitate the development of models that reliably estimate the proportion of production sequestered, improvements in macroalgae carbon fingerprinting techniques, and a rethinking of carbon accounting methodologies. The ocean provides major opportunities to mitigate and adapt to climate change, and the largest coastal vegetated habitat on Earth should not be ignored simply because it does not fit into existing frameworks.
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Affiliation(s)
- Albert Pessarrodona
- UWA Oceans Institute and School of Biological Sciences, University of Western Australia, Crawley, 6009, Western Australia, Australia
- Conservation International, 2011 Crystal Dr., Suite 600, Arlington, VA, USA
- International Blue Carbon Institute, 42B Boat Quay, Singapore, 049831, Singapore
| | - Rita M Franco-Santos
- CSIRO Environment, Indian Ocean Marine Research Centre, Crawley, 6009, Western Australia, Australia
| | - Luka Seamus Wright
- UWA Oceans Institute and School of Biological Sciences, University of Western Australia, Crawley, 6009, Western Australia, Australia
- CSIRO Environment, Indian Ocean Marine Research Centre, Crawley, 6009, Western Australia, Australia
| | - Mathew A Vanderklift
- CSIRO Environment, Indian Ocean Marine Research Centre, Crawley, 6009, Western Australia, Australia
| | - Jennifer Howard
- Conservation International, 2011 Crystal Dr., Suite 600, Arlington, VA, USA
- International Blue Carbon Institute, 42B Boat Quay, Singapore, 049831, Singapore
| | - Emily Pidgeon
- Conservation International, 2011 Crystal Dr., Suite 600, Arlington, VA, USA
- International Blue Carbon Institute, 42B Boat Quay, Singapore, 049831, Singapore
| | - Thomas Wernberg
- UWA Oceans Institute and School of Biological Sciences, University of Western Australia, Crawley, 6009, Western Australia, Australia
- Institute of Marine Research, Nye Flødevigveien 20, His, 4817, Norway
| | - Karen Filbee-Dexter
- UWA Oceans Institute and School of Biological Sciences, University of Western Australia, Crawley, 6009, Western Australia, Australia
- Institute of Marine Research, Nye Flødevigveien 20, His, 4817, Norway
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15
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Fourquez M, Janssen DJ, Conway TM, Cabanes D, Ellwood MJ, Sieber M, Trimborn S, Hassler C. Chasing iron bioavailability in the Southern Ocean: Insights from Phaeocystis antarctica and iron speciation. SCIENCE ADVANCES 2023; 9:eadf9696. [PMID: 37379397 DOI: 10.1126/sciadv.adf9696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 05/24/2023] [Indexed: 06/30/2023]
Abstract
Dissolved iron (dFe) availability limits the uptake of atmospheric CO2 by the Southern Ocean (SO) biological pump. Hence, any change in bioavailable dFe in this region can directly influence climate. On the basis of Fe uptake experiments with Phaeocystis antarctica, we show that the range of dFe bioavailability in natural samples is wider (<1 to ~200% compared to free inorganic Fe') than previously thought, with higher bioavailability found near glacial sources. The degree of bioavailability varied regardless of in situ dFe concentration and depth, challenging the consensus that sole dFe concentrations can be used to predict Fe uptake in modeling studies. Further, our data suggest a disproportionately major role of biologically mediated ligands and encourage revisiting the role of humic substances in influencing marine Fe biogeochemical cycling in the SO. Last, we describe a linkage between in situ dFe bioavailability and isotopic signatures that, we anticipate, will stimulate future research.
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Affiliation(s)
- Marion Fourquez
- Aix Marseille Univ., Université de Toulon, CNRS, IRD, MIO UMR 110, Marseille 13288, France
- University of Geneva, Department F.-A. Forel for Environmental and Aquatic Sciences, Geneva 1211, Switzerland
| | - David J Janssen
- Department Surface Waters, Eawag-Swiss Federal Institute of Aquatic Science and Technology, Kastanienbaum, Switzerland
| | - Tim M Conway
- College of Marine Science, University of South Florida, St. Petersburg, FL 33701, USA
| | - Damien Cabanes
- University of Geneva, Department F.-A. Forel for Environmental and Aquatic Sciences, Geneva 1211, Switzerland
| | - Michael J Ellwood
- Research School of Earth Sciences, Australian National University, Canberra, ACT, Australia
- Australian Centre for Excellence in Antarctic Science, Research School of Earth Sciences, Australian National University, Canberra, ACT, Australia
| | - Matthias Sieber
- College of Marine Science, University of South Florida, St. Petersburg, FL 33701, USA
- Institute of Geochemistry and Petrology, ETH Zürich, Zürich, Switzerland
| | - Scarlett Trimborn
- Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research, Bremerhaven 27570, Germany
| | - Christel Hassler
- University of Geneva, Department F.-A. Forel for Environmental and Aquatic Sciences, Geneva 1211, Switzerland
- Institute of Earth Sciences, University of Lausanne, Lausanne 1015, Switzerland
- School of Architecture, Civil, and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne, Sion 1951, Switzerland
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Trinh R, Ducklow HW, Steinberg DK, Fraser WR. Krill body size drives particulate organic carbon export in West Antarctica. Nature 2023; 618:526-530. [PMID: 37316721 DOI: 10.1038/s41586-023-06041-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 03/31/2023] [Indexed: 06/16/2023]
Abstract
The export of carbon from the ocean surface and storage in the ocean interior is important in the modulation of global climate1-4. The West Antarctic Peninsula experiences some of the largest summer particulate organic carbon (POC) export rates, and one of the fastest warming rates, in the world5,6. To understand how warming may alter carbon storage, it is necessary to first determine the patterns and ecological drivers of POC export7,8. Here we show that Antarctic krill (Euphausia superba) body size and life-history cycle, as opposed to their overall biomass or regional environmental factors, exert the dominant control on the POC flux. We measured POC fluxes over 21 years, the longest record in the Southern Ocean, and found a significant 5-year periodicity in the annual POC flux, which oscillated in synchrony with krill body size, peaking when the krill population was composed predominately of large individuals. Krill body size alters the POC flux through the production and export of size-varying faecal pellets9, which dominate the total flux. Decreases in winter sea ice10, an essential habitat for krill, are causing shifts in the krill population11, which may alter these export patterns of faecal pellets, leading to changes in ocean carbon storage.
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Affiliation(s)
- Rebecca Trinh
- Deparment of Earth and Environmental Sciences, Columbia University, New York, NY, USA.
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA.
| | - Hugh W Ducklow
- Deparment of Earth and Environmental Sciences, Columbia University, New York, NY, USA
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA
| | - Deborah K Steinberg
- Virginia Institute of Marine Science, William & Mary, Gloucester Point, VA, USA
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