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Quintanilla JM, Borrego-Santos R, Malca E, Swalethorp R, Landry MR, Gerard T, Lamkin J, García A, Laiz-Carrión R. Maternal Effects and Trophodynamics Drive Interannual Larval Growth Variability of Atlantic Bluefin Tuna ( Thunnus thynnus) from the Gulf of Mexico. Animals (Basel) 2024; 14:1319. [PMID: 38731323 PMCID: PMC11083439 DOI: 10.3390/ani14091319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 04/19/2024] [Accepted: 04/24/2024] [Indexed: 05/13/2024] Open
Abstract
Two cohorts of Atlantic bluefin tuna (Thunnus thynnus) larvae were sampled in 2017 and 2018 during the peak of spawning in the Gulf of Mexico (GOM). We examined environmental variables, daily growth, otolith biometry and stable isotopes and found that the GOM18 cohort grew at faster rates, with larger and wider otoliths. Inter and intra-population analyses (deficient vs. optimal growth groups) were carried out for pre- and post-flexion developmental stages to determine maternal and trophodynamic influences on larval growth variability based on larval isotopic signatures, trophic niche sizes and their overlaps. For the pre-flexion stages in both years, the optimal growth groups had significantly lower δ15N, implying a direct relationship between growth potential and maternal inheritance. Optimal growth groups and stages for both years showed lower C:N ratios, reflecting a greater energy investment in growth. The results of this study illustrate the interannual transgenerational trophic plasticity of a spawning stock and its linkages to growth potential of their offsprings in the GOM.
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Affiliation(s)
- José M. Quintanilla
- Instituto Español de Oceanografía (IEO-CSIC), Centro Oceanográfico de Málaga, 29640 Fuengirola, Spain; (R.B.-S.); (A.G.); (R.L.-C.)
| | - Ricardo Borrego-Santos
- Instituto Español de Oceanografía (IEO-CSIC), Centro Oceanográfico de Málaga, 29640 Fuengirola, Spain; (R.B.-S.); (A.G.); (R.L.-C.)
- Departamento de Biología Animal, Facultad de Ciencias, Universidad de Málaga, 29071 Málaga, Spain
| | - Estrella Malca
- Cooperative Institute for Marine and Atmospheric Studies, University of Miami, Miami, FL 33149, USA;
- NOAA Fisheries, Southeast Fisheries Science Center, Miami, FL 33149, USA; (T.G.); (J.L.)
| | - Rasmus Swalethorp
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037, USA; (R.S.); (M.R.L.)
| | - Michael R. Landry
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92037, USA; (R.S.); (M.R.L.)
| | - Trika Gerard
- NOAA Fisheries, Southeast Fisheries Science Center, Miami, FL 33149, USA; (T.G.); (J.L.)
| | - John Lamkin
- NOAA Fisheries, Southeast Fisheries Science Center, Miami, FL 33149, USA; (T.G.); (J.L.)
| | - Alberto García
- Instituto Español de Oceanografía (IEO-CSIC), Centro Oceanográfico de Málaga, 29640 Fuengirola, Spain; (R.B.-S.); (A.G.); (R.L.-C.)
| | - Raúl Laiz-Carrión
- Instituto Español de Oceanografía (IEO-CSIC), Centro Oceanográfico de Málaga, 29640 Fuengirola, Spain; (R.B.-S.); (A.G.); (R.L.-C.)
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2
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Swalethorp R, Landry MR, Semmens BX, Ohman MD, Aluwihare L, Chargualaf D, Thompson AR. Anchovy boom and bust linked to trophic shifts in larval diet. Nat Commun 2023; 14:7412. [PMID: 38052790 DOI: 10.1038/s41467-023-42966-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 10/27/2023] [Indexed: 12/07/2023] Open
Abstract
Although massive biomass fluctuations of coastal-pelagic fishes are an iconic example of the impacts of climate variability on marine ecosystems, the mechanisms governing these dynamics are often elusive. We construct a 45-year record of nitrogen stable isotopes measured in larvae of Northern Anchovy (Engraulis mordax) in the California Current Ecosystem to assess patterns in food chain length. Larval trophic efficiency associated with a shortened food chain increased larval survival and produced boom periods of high adult biomass. In contrast, when larval food chain length increased, and energy transfer efficiency decreased, the population crashed. We propose the Trophic Efficiency in Early Life (TEEL) hypothesis, which states that larval fishes must consume prey that confer sufficient energy for survival, to help explain natural boom-bust dynamics of coastal pelagic fishes. Our findings illustrate a potential for trophic indicators to generally inform larval survival and adult population dynamics of coastal-pelagic fishes.
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Affiliation(s)
- Rasmus Swalethorp
- Scripps Institution of Oceanography, University of California - San Diego, La Jolla, CA, USA.
- NOAA Fisheries Service, Southwest Fisheries Science Center, La Jolla, CA, USA.
- National Institute of Aquatic Resources (DTU Aqua), Technical University of Denmark, Kgs., Lyngby, Denmark.
| | - Michael R Landry
- Scripps Institution of Oceanography, University of California - San Diego, La Jolla, CA, USA
| | - Brice X Semmens
- Scripps Institution of Oceanography, University of California - San Diego, La Jolla, CA, USA
| | - Mark D Ohman
- Scripps Institution of Oceanography, University of California - San Diego, La Jolla, CA, USA
| | - Lihini Aluwihare
- Scripps Institution of Oceanography, University of California - San Diego, La Jolla, CA, USA
| | - Dereka Chargualaf
- NOAA Fisheries Service, Southwest Fisheries Science Center, La Jolla, CA, USA
| | - Andrew R Thompson
- NOAA Fisheries Service, Southwest Fisheries Science Center, La Jolla, CA, USA
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3
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Landry MR, Stukel MR, Selph KE, Goericke R. Coexisting picoplankton experience different relative grazing pressures across an ocean productivity gradient. Proc Natl Acad Sci U S A 2023; 120:e2220771120. [PMID: 37871180 PMCID: PMC10622918 DOI: 10.1073/pnas.2220771120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 08/30/2023] [Indexed: 10/25/2023] Open
Abstract
Picophytoplankton populations [Prochlorococcus, Synechococcus (SYN), and picoeukaryotes] are dominant primary producers in the open ocean and projected to become more important with climate change. Their fates can vary, however, with microbial food web complexities. In the California Current Ecosystem, picophytoplankton biomass and abundance peak in waters of intermediate productivity and decrease at higher production. Using experimental data from eight cruises crossing the pronounced CCE trophic gradient, we tested the hypothesis that these declines are driven by intensified grazing on heterotrophic bacteria (HBAC) passed to similarly sized picophytoplankton via shared predators. Results confirm previously observed distributions as well as significant increases in bacterial abundance, cell growth, and grazing mortality with primary production. Mortalities of picophytoplankton, however, diverge from the bacterial mortality trend such that relative grazing rates on SYN compared to HBAC decline by 12-fold between low and high productivity waters. The large shifts in mortality rate ratios for coexisting populations are not explained by size variability but rather suggest high selectivity of grazer assemblages or tightly coupled tradeoffs in microbial growth advantages and grazing vulnerabilities. These findings challenge the long-held view that protistan grazing mainly determines overall biomass of microbial communities while viruses uniquely regulate diversity by "killing the winners".
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Affiliation(s)
- Michael R. Landry
- Scripps Institution of Oceanography, University of California at San Diego, San Diego, CA92093
| | - Michael R. Stukel
- Earth, Ocean, and Atmospheric Science Department, Florida State University, Tallahassee, FL32306
| | - Karen E. Selph
- Department of Oceanography, University of Hawai’i at Manoa, Honolulu, HI96822
| | - Ralf Goericke
- Scripps Institution of Oceanography, University of California at San Diego, San Diego, CA92093
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4
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Stukel MR, Gerard T, Kelly TB, Knapp AN, Laiz-Carrión R, Lamkin JT, Landry MR, Malca E, Selph KE, Shiroza A, Shropshire TA, Swalethorp R. Plankton food webs in the oligotrophic Gulf of Mexico spawning grounds of Atlantic bluefin tuna. J Plankton Res 2022; 44:763-781. [PMID: 36045950 PMCID: PMC9424712 DOI: 10.1093/plankt/fbab023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 03/08/2021] [Accepted: 03/17/2021] [Indexed: 06/15/2023]
Abstract
We used linear inverse ecosystem modeling techniques to assimilate data from extensive Lagrangian field experiments into a mass-balance constrained food web for the Gulf of Mexico open-ocean ecosystem. This region is highly oligotrophic, yet Atlantic bluefin tuna (ABT) travel long distances from feeding grounds in the North Atlantic to spawn there. Our results show extensive nutrient regeneration fueling primary productivity (mostly by cyanobacteria and other picophytoplankton) in the upper euphotic zone. The food web is dominated by the microbial loop (>70% of net primary productivity is respired by heterotrophic bacteria and protists that feed on them). By contrast, herbivorous food web pathways from phytoplankton to metazoan zooplankton process <10% of the net primary production in the mixed layer. Nevertheless, ABT larvae feed preferentially on podonid cladocerans and other suspension-feeding zooplankton, which in turn derive much of their nutrition from nano- and micro-phytoplankton (mixotrophic flagellates, and to a lesser extent, diatoms). This allows ABT larvae to maintain a comparatively low trophic level (~4.2 for preflexion and postflexion larvae), which increases trophic transfer from phytoplankton to larval fish.
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Affiliation(s)
| | - Trika Gerard
- Southeast Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration (NOAA), Miami, FL 33149, USA
| | - Thomas B Kelly
- Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL 32306, USA
| | - Angela N Knapp
- Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL 32306, USA
| | - Raúl Laiz-Carrión
- Centro Oceanográfico De Malaga, Instituto Español Del Oceanografía, Fuengirola, Spain
| | - John T Lamkin
- Southeast Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration (NOAA), Miami, FL 33149, USA
| | - Michael R Landry
- Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
| | - Estrella Malca
- Cooperative Institute For Marine and Atmospheric Studies, University Of Miami, Miami, FL 33149, USA
| | - Karen E Selph
- Department of Oceanography, University of Hawaii At Manoa, Honolulu, HI 96822, USA
| | - Akihiro Shiroza
- Cooperative Institute For Marine and Atmospheric Studies, University Of Miami, Miami, FL 33149, USA
| | - Taylor A Shropshire
- Department of Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL 32306, USA
- Center for Ocean-Atmospheric Prediction Studies, Florida State University, Tallahassee, FL 32306, USA
| | - Rasmus Swalethorp
- Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
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Valencia B, Stukel MR, Allen AE, McCrow JP, Rabines A, Palenik B, Landry MR. Relating sinking and suspended microbial communities in the California Current Ecosystem: digestion resistance and the contributions of phytoplankton taxa to export. Environ Microbiol 2021; 23:6734-6748. [PMID: 34431195 DOI: 10.1111/1462-2920.15736] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 08/21/2021] [Indexed: 11/27/2022]
Abstract
We used 16S, 18S, plastid and internal transcribed spacer (for Synechococcus strains) sequencing to quantify relative microbial abundances in water-column samples and on sediment-trap-collected particles across an environmental gradient in the California Current Ecosystem (CCE) spanning a > 60-fold range of surface chlorophyll. Most mixed-layer dominant eukaryotes and prokaryotes were consistently underrepresented on sinking particles. Diatoms were the only phototrophic taxa consistently overrepresented. Even within this class, however, one genus (Thalassiosira) was a particle-enriched dominant, while a similarly abundant species was poorly represented. Synechococcus was significantly enriched on sinking particles at only one of four sites, but clade I was disproportionately abundant on sinking particles throughout the region compared with clade IV, the euphotic-zone co-dominant. The most abundant microbes on particles across the CCE were organisms with distributional maxima close to the sediment-trap depth (rhizarians), microbes associated with metazoans or sinking particles as a nutritional habitat (certain alveolates, Gammaproteobacteria) and organisms that resist digestive degradation of their DNA (Thalassiosira, Synechococcus). For assessing taxon contributions of phytoplankton to carbon export, our results highlight the need for sequence-based quantitative approaches that can be used to integrate euphotic-zone abundances, compute rates and account for taxon differences in preservation of sequence markers through trophic processing.
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Affiliation(s)
- Bellineth Valencia
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Michael R Stukel
- Earth, Ocean, and Atmospheric Science Department, Florida State University, Tallahassee, FL, USA
| | - Andrew E Allen
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA.,Microbial and Environmental Genomics, J Craig Venter Institute, La Jolla, CA, USA
| | - John P McCrow
- Microbial and Environmental Genomics, J Craig Venter Institute, La Jolla, CA, USA
| | - Ariel Rabines
- Microbial and Environmental Genomics, J Craig Venter Institute, La Jolla, CA, USA
| | - Brian Palenik
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Michael R Landry
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
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6
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Kelly TB, Knapp AN, Landry MR, Selph KE, Shropshire TA, Thomas RK, Stukel MR. Lateral advection supports nitrogen export in the oligotrophic open-ocean Gulf of Mexico. Nat Commun 2021; 12:3325. [PMID: 34083545 PMCID: PMC8175579 DOI: 10.1038/s41467-021-23678-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 05/11/2021] [Indexed: 11/08/2022] Open
Abstract
In contrast to its productive coastal margins, the open-ocean Gulf of Mexico (GoM) is notable for highly stratified surface waters with extremely low nutrient and chlorophyll concentrations. Field campaigns in 2017 and 2018 identified low rates of turbulent mixing, which combined with oligotrophic nutrient conditions, give very low estimates for diffusive flux of nitrate into the euphotic zone (< 1 µmol N m-2 d-1). Estimates of local N2-fixation are similarly low. In comparison, measured export rates of sinking particulate organic nitrogen (PON) from the euphotic zone are 2 - 3 orders of magnitude higher (i.e. 462 - 1144 µmol N m-2 d-1). We reconcile these disparate findings with regional scale dynamics inferred independently from remote-sensing products and a regional biogeochemical model and find that laterally-sourced organic matter is sufficient to support >90% of open-ocean nitrogen export in the GoM. Results show that lateral transport needs to be closely considered in studies of biogeochemical balances, particularly for basins enclosed by productive coasts.
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Affiliation(s)
- Thomas B Kelly
- Department of Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL, USA.
- Center for Ocean-Atmospheric Prediction Studies, Florida State University, Tallahassee, FL, USA.
- College of Fisheries and Ocean Science, University of Alaska Fairbanks, Fairbanks, AK, USA.
| | - Angela N Knapp
- Department of Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL, USA
| | - Michael R Landry
- Integrative Oceanography Division, Scripps Institution of Oceanography, La Jolla, CA, USA
| | - Karen E Selph
- Department of Oceanography, University of Hawaii at Manoa, Honolulu, HI, USA
| | - Taylor A Shropshire
- Department of Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL, USA
- Center for Ocean-Atmospheric Prediction Studies, Florida State University, Tallahassee, FL, USA
| | - Rachel K Thomas
- Department of Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL, USA
| | - Michael R Stukel
- Department of Earth, Ocean and Atmospheric Sciences, Florida State University, Tallahassee, FL, USA
- Center for Ocean-Atmospheric Prediction Studies, Florida State University, Tallahassee, FL, USA
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7
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Gutierrez-Rodriguez A, Stukel MR, Lopes Dos Santos A, Biard T, Scharek R, Vaulot D, Landry MR, Not F. High contribution of Rhizaria (Radiolaria) to vertical export in the California Current Ecosystem revealed by DNA metabarcoding. ISME J 2019; 13:964-976. [PMID: 30538274 PMCID: PMC6461850 DOI: 10.1038/s41396-018-0322-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 10/18/2018] [Accepted: 11/17/2018] [Indexed: 11/08/2022]
Abstract
Passive sinking of particulate organic matter (POM) is the main mechanism through which the biological pump transports surface primary production to the ocean interior. However, the contribution and variability of different biological sources to vertical export is not fully understood. Here, we use DNA metabarcoding of the 18S rRNA gene and particle interceptor traps (PITs) to characterize the taxonomic composition of particles sinking out of the photic layer in the California Current Ecosystem (CCE), a productive system with high export potential. The PITs included formalin-fixed and 'live' traps to investigate eukaryotic communities involved in the export and remineralization of sinking particles. Sequences affiliated with Radiolaria dominated the eukaryotic assemblage in fixed traps (90%), with Dinophyta and Metazoa making minor contributions. The prominence of Radiolaria decreased drastically in live traps, possibly due to selective consumption by copepods, heterotrophic nanoflagellates, and phaeodarians that were heavily enriched in these traps. These patterns were consistent across the water masses surveyed extending from the coast to offshore, despite major differences in productivity and trophic structure of the epipelagic plankton community. Our findings identify Radiolaria as major actors in export fluxes in the CCE.
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Affiliation(s)
- Andres Gutierrez-Rodriguez
- Sorbonne Université, CNRS, UMR7144, Adaptation and Diversity in Marine Environment (AD2M) laboratory, Ecology of Marine Plankton team, Station Biologique de Roscoff, Place Georges Teissier, Roscoff, 29680, France.
- National Institute of Water and Atmospheric Research, 301 Evans Bay Parade, Wellington, 6021, New Zealand.
| | - Michael R Stukel
- Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL, 32304, USA
| | - Adriana Lopes Dos Santos
- Sorbonne Université, CNRS, UMR7144, Adaptation and Diversity in Marine Environment (AD2M) laboratory, Ecology of Marine Plankton team, Station Biologique de Roscoff, Place Georges Teissier, Roscoff, 29680, France
- GEMA Center for Genomics, Ecology & Environment, Facultad de Ciencias, Universidad Mayor, Camino La Pirámide, Huechuraba, 5750, Santiago, Chile
- Asian School of the Environment, Nanyang Technological University, 50 Nanyang Avenue, 639798A, Singapore
| | - Tristan Biard
- Sorbonne Université, CNRS, UMR7144, Adaptation and Diversity in Marine Environment (AD2M) laboratory, Ecology of Marine Plankton team, Station Biologique de Roscoff, Place Georges Teissier, Roscoff, 29680, France
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Renate Scharek
- Instituto Español de Oceanografía, Centro Oceanográfico de Gijón, Avda Príncipe de Asturias 70 bis, Gijón, 33212, Spain
| | - Daniel Vaulot
- Sorbonne Université, CNRS, UMR7144, Adaptation and Diversity in Marine Environment (AD2M) laboratory, Ecology of Marine Plankton team, Station Biologique de Roscoff, Place Georges Teissier, Roscoff, 29680, France
| | - Michael R Landry
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Fabrice Not
- Sorbonne Université, CNRS, UMR7144, Adaptation and Diversity in Marine Environment (AD2M) laboratory, Ecology of Marine Plankton team, Station Biologique de Roscoff, Place Georges Teissier, Roscoff, 29680, France
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9
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Abstract
Marine zooplankton comprise a phylogenetically and functionally diverse assemblage of protistan and metazoan consumers that occupy multiple trophic levels in pelagic food webs. Within this complex network, carbon flows via alternative zooplankton pathways drive temporal and spatial variability in production-grazing coupling, nutrient cycling, export, and transfer efficiency to higher trophic levels. We explore current knowledge of the processing of zooplankton food ingestion by absorption, egestion, respiration, excretion, and growth (production) processes. On a global scale, carbon fluxes are reasonably constrained by the grazing impact of microzooplankton and the respiratory requirements of mesozooplankton but are sensitive to uncertainties in trophic structure. The relative importance, combined magnitude, and efficiency of export mechanisms (mucous feeding webs, fecal pellets, molts, carcasses, and vertical migrations) likewise reflect regional variability in community structure. Climate change is expected to broadly alter carbon cycling by zooplankton and to have direct impacts on key species.
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Affiliation(s)
- Deborah K Steinberg
- Virginia Institute of Marine Science, The College of William and Mary, Gloucester Point, Virginia 23062;
| | - Michael R Landry
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093;
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10
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Winder M, Burian A, Landry MR, Montagnes DJ, Nielsen JM. Technical comment on Boersma et al. (2016) Temperature driven changes in the diet preference of omnivorous copepods: no more meat when it's hot? Ecology Letters, 19, 45-53. Ecol Lett 2016; 19:1389-1391. [PMID: 27634214 DOI: 10.1111/ele.12668] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 07/26/2016] [Indexed: 12/01/2022]
Abstract
A recent study concluded that omnivorous plankton will shift from predatory to herbivorous feeding with climate warming, as consumers require increased carbon:phosphorous in their food. Although this is an appealing hypothesis, we suggest the conclusion is unfounded, based on the data presented, which seem in places questionable and poorly interpreted.
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Affiliation(s)
- Monika Winder
- Department of Ecology, Environment, and Plant Sciences, Stockholm University, 10691, Stockholm, Sweden.
| | - Alfred Burian
- Department of Ecology, Environment, and Plant Sciences, Stockholm University, 10691, Stockholm, Sweden
| | - Michael R Landry
- Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA, 92093-0227, USA
| | - David Js Montagnes
- Institute of Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Jens M Nielsen
- Department of Ecology, Environment, and Plant Sciences, Stockholm University, 10691, Stockholm, Sweden
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11
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Zhang S, Chan KYK, Shen Z, Cheung S, Landry MR, Liu H. A Cryptic Marine Ciliate Feeds on Progametes of Noctiluca scintillans. Protist 2016; 168:1-11. [PMID: 27888714 DOI: 10.1016/j.protis.2016.08.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 07/31/2016] [Accepted: 08/19/2016] [Indexed: 10/21/2022]
Abstract
The dinoflagellate Noctiluca scintillans (Noctiluca) has the ability to reproduce sexually, which may help to increase or restore its population size during periods of blooms or environmental stress. Here, we documented for the first time a marine ciliate Strombidium sp. that feeds on Noctiluca's progametes undergoing stages 5 to 9 of nuclear division. This ciliate frequently swam on or around gametogenic and some vegetative Noctiluca cells. The ciliates associated with gametogenic cells had significantly lower swimming speed and changed direction more frequently than those associated with vegetative cells, which overall increased their time spent around the food patches (progametes). This trophic interaction constitutes an upside-down predator-prey link, in which ciliates within the typical size range of Noctiluca prey, become the predators. Based on the phylogenetic tree (maximum-likelihood), there are 14 environmental clones similar to Strombidium sp. found in other coastal waters, where Noctiluca presence or blooms have been reported. This novel predator-prey relationship could therefore be common in other Noctiluca habitats. Additional studies are needed to assess the magnitude of its impacts on Noctiluca population dynamics and plankton bloom succession.
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Affiliation(s)
- Shuwen Zhang
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong Special Administrative Region
| | - Kit Yu Karen Chan
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong Special Administrative Region
| | - Zhuo Shen
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong Special Administrative Region; Institute of Hydrobiology, Jinan University, Guangzhou, China
| | - Shunyan Cheung
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong Special Administrative Region
| | - Michael R Landry
- Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA, USA
| | - Hongbin Liu
- Division of Life Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong Special Administrative Region.
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12
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Baines SB, Chen X, Vogt S, Fisher NS, Twining BS, Landry MR. Microplankton trace element contents: implications for mineral limitation of mesozooplankton in an HNLC area. J Plankton Res 2016; 38:256-270. [PMID: 27275029 PMCID: PMC4889991 DOI: 10.1093/plankt/fbv109] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2015] [Accepted: 11/19/2015] [Indexed: 05/25/2023]
Abstract
Mesozooplankton production in high-nutrient low-chlorophyll regions of the ocean may be reduced if the trace element concentrations in their food are insufficient to meet growth and metabolic demands. We used elemental microanalysis (SXRF) of single-celled plankton to determine their trace metal contents during a series of semi-Lagrangian drift studies in an HNLC upwelling region, the Costa Rica Dome (CRD). Cells from the surface mixed layer had lower Fe:S but higher Zn:S and Ni:S than those from the subsurface chlorophyll maximum at 22-30 m. Diatom Fe:S values were typically 3-fold higher than those in flagellated cells. The ratios of Zn:C in flagellates and diatoms were generally similar to each other, and to co-occurring mesozooplankton. Estimated Fe:C ratios in flagellates were lower than those in co-occurring mesozooplankton, sometimes by more than 3-fold. In contrast, Fe:C in diatoms was typically similar to that in zooplankton. RNA:DNA ratios in the CRD were low compared with other regions, and were related to total autotrophic biomass and weakly to the discrepancy between Zn:C in flagellated cells and mesozooplankton tissues. Mesozooplankton may have been affected by the trace element content of their food, even though trace metal limitation of phytoplankton was modest at best.
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Affiliation(s)
- Stephen B. Baines
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY 11789-5245, USA
| | - Xi Chen
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11789-5000, USA
| | - Stefan Vogt
- Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Nicholas S. Fisher
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11789-5000, USA
| | | | - Michael R. Landry
- Scripps Institution of Oceanography, University of California at San Diego, 9500 Gilman Dr, La Jolla, CA 92093-0227, USA
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Selph KE, Landry MR, Taylor AG, Gutiérrez-Rodríguez A, Stukel MR, Wokuluk J, Pasulka A. Phytoplankton production and taxon-specific growth rates in the Costa Rica Dome. J Plankton Res 2016; 38:199-215. [PMID: 27275025 PMCID: PMC4889980 DOI: 10.1093/plankt/fbv063] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Accepted: 07/13/2015] [Indexed: 05/25/2023]
Abstract
During summer 2010, we investigated phytoplankton production and growth rates at 19 stations in the eastern tropical Pacific, where winds and strong opposing currents generate the Costa Rica Dome (CRD), an open-ocean upwelling feature. Primary production (14C-incorporation) and group-specific growth and net growth rates (two-treatment seawater dilution method) were estimated from samples incubated in situ at eight depths. Our cruise coincided with a mild El Niño event, and only weak upwelling was observed in the CRD. Nevertheless, the highest phytoplankton abundances were found near the dome center. However, mixed-layer growth rates were lowest in the dome center (∼0.5-0.9 day-1), but higher on the edge of the dome (∼0.9-1.0 day-1) and in adjacent coastal waters (0.9-1.3 day-1). We found good agreement between independent methods to estimate growth rates. Mixed-layer growth rates of Prochlorococcus and Synechococcus were largely balanced by mortality, whereas eukaryotic phytoplankton showed positive net growth (∼0.5-0.6 day-1), that is, growth available to support larger (mesozooplankton) consumer biomass. These are the first group-specific phytoplankton rate estimates in this region, and they demonstrate that integrated primary production is high, exceeding 1 g C m-2 day-1 on average, even during a period of reduced upwelling.
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Affiliation(s)
- Karen E. Selph
- Department of Oceanography, University of Hawaii at Manoa, Honolulu, HI 96822, USA
| | - Michael R. Landry
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
| | - Andrew G. Taylor
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
| | - Andrés Gutiérrez-Rodríguez
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
- Centre National de la Recherche Scientifique and Universite Pierre et Marie Curie, Station Biologique, 29680 Roscoff, France
| | - Michael R. Stukel
- Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL 32306, USA
| | - John Wokuluk
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
| | - Alexis Pasulka
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
- Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
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Freibott A, Taylor AG, Selph KE, Liu H, Zhang W, Landry MR. Biomass and composition of protistan grazers and heterotrophic bacteria in the Costa Rica Dome during summer 2010. J Plankton Res 2016; 38:230-243. [PMID: 27275027 PMCID: PMC4889989 DOI: 10.1093/plankt/fbv107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 11/19/2015] [Indexed: 05/10/2023]
Abstract
We investigated biomass and composition of heterotrophic microbes in the Costa Rica Dome during June-July 2010 as part of a broader study of plankton trophic dynamics. Because picophytoplankton (<2 μm) are known to dominate in this unique upwelling region, we hypothesized tight biomass relationships between size-determined predator-prey pairs (i.e. picoplankton-nano-grazers, nanoplankton-micro-grazers) within the microbial community. Integrated biomass of heterotrophic bacteria ranged from 180 to 487 mg C m-2 and was significantly correlated with total autotrophic carbon. Heterotrophic protist (H-protist) biomass ranged more narrowly from 488 to 545 mg C m-2, and was comprised of 60% dinoflagellates, 30% other flagellates and 11% ciliates. Nano-sized (<20 μm) protists accounted for the majority (57%) of grazer biomass and were positively correlated with picoplankton, partially supporting our hypothesis, but nanoplankton and micro-grazers (>20 μm) were not significantly correlated. The relative constancy of H-protist biomass among locations despite clear changes in integrated autotrophic biomass, Chl a, and primary production suggests that mesozooplankton may exert a tight top-down control on micro-grazers. Biomass-specific consumption rates of phytoplankton by protistan grazers suggest an instantaneous growth rate of 0.52 day-1 for H-protists, similar to the growth rate of phytoplankton and consistent with a trophically balanced ecosystem dominated by pico-nanoplankton interactions.
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Affiliation(s)
- Alexandra Freibott
- Scripps Institution of Oceanography, University of California at San Diego, 9500 Gilman Dr., La Jolla, CA, USA
- CORRESPONDING AUTHOR:
| | - Andrew G. Taylor
- Scripps Institution of Oceanography, University of California at San Diego, 9500 Gilman Dr., La Jolla, CA, USA
| | - Karen E. Selph
- Department of Oceanography, University of Hawaii at Manoa, Honolulu, HI, USA
| | - Hongbin Liu
- The Hong Kong University of Science and Technology, Hong Kong Sar, China
| | - Wuchang Zhang
- Institute of Oceanography, Chinese Academy of Science, Qingdao, China
| | - Michael R. Landry
- Scripps Institution of Oceanography, University of California at San Diego, 9500 Gilman Dr., La Jolla, CA, USA
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Gutiérrez-Rodríguez A, Selph KE, Landry MR. Phytoplankton growth and microzooplankton grazing dynamics across vertical environmental gradients determined by transplant in situ dilution experiments. J Plankton Res 2016; 38:271-289. [PMID: 27275030 PMCID: PMC4889981 DOI: 10.1093/plankt/fbv074] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 08/09/2015] [Indexed: 05/25/2023]
Abstract
The Costa Rica Dome (CRD) represents a classic case of the bloom-forming capacity of small phytoplankton. Unlike other upwelling systems, autotrophic biomass in the CRD is dominated by picocyanobacteria and small eukaryotes that outcompete larger diatoms and reach extremely high biomass levels. We investigated responses of the subsurface phytoplankton community of the CRD to changes associated with vertical displacement of water masses, coupling in situ transplanted dilution experiments with flow cytometry and epifluorescence microscopy to assess group-specific dynamics. Growth rates of Synechococcus (SYN) and photosynthetic picoeukaryotes (PEUK) were positively correlated with light (Rpearson_SYN = 0.602 and Rpearson_PEUK = 0.588, P < 0.001). Growth rates of Prochlorococcus (PRO), likely affected by photoinhibition, were not light correlated (Rpearson_PRO = 0.101, P = 0.601). Overall, grazing and growth rates were closely coupled in all picophytoplankton groups (Rspearman_PRO = 0.572, Rspearman_SYN = 0.588, Rspearman_PEUK = 0.624), and net growth rates remained close to zero. Conversely, the abundance and biomass of larger phytoplankton, mainly diatoms, increased more than 10-fold in shallower transplant incubations indicating that, in addition to trace-metal chemistry, light also plays a significant role in controlling microphytoplankton populations in the CRD.
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Affiliation(s)
| | - Karen E Selph
- Department of Oceanography , University of Hawaii at Manoa , Honolulu, Hi 96822 , USA
| | - Michael R Landry
- Scripps Institution of Oceanography , 9500 Gilman Dr., La Jolla, CA 92093-0227 , USA
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Krause JW, Stukel MR, Taylor AG, Taniguchi DAA, De Verneil A, Landry MR. Net biogenic silica production and the contribution of diatoms to new production and organic matter export in the Costa Rica Dome ecosystem. J Plankton Res 2016; 38:216-229. [PMID: 27275026 PMCID: PMC4889982 DOI: 10.1093/plankt/fbv077] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 08/21/2015] [Indexed: 05/25/2023]
Abstract
We determined the net rate of biogenic silica (bSiO2) production and estimated the diatom contribution to new production and organic matter export in the Costa Rica Dome during summer 2010. The shallow thermocline significantly reduces bSiO2 dissolution rates below the mixed layer, leading to significant enhancement of bSiO2 relative to organic matter (silicate-pump condition). This may explain why deep export of bSiO2 in this region is elevated by an order of magnitude relative to comparable systems. Diatom carbon, relative to autotrophic carbon, was low (<3%); however, the contribution of diatoms to new production averaged 3 and 13% using independent approaches. The 4-old discrepancy between methods may be explained by a low average C:Si ratio (∼1.4) for the net produced diatom C relative to the net produced bSiO2. We speculate that this low production ratio is not the result of reduced C, but may arise from a significant contribution of non-diatom silicifying organisms to bSiO2 production. The contribution of diatoms to organic matter export was minor (5.7%). These results, and those of the broader project, suggest substantial food-web transformation of diatom organic matter in the euphotic zone, which creates enriched bSiO2 relative to organic matter within the exported material.
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Affiliation(s)
- Jeffrey W. Krause
- Dauphin Island Sea Lab, 101 Bienville BLVD, Dauphin Island, AL 36528, USA
- University of South Alabama, Life Sciences Building Room 25, Mobile, AL 36688, USA
| | - Michael R. Stukel
- Florida State University, P.O. Box 3064520, Tallahassee, FL 32306-4520, USA
| | - Andrew G. Taylor
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
| | - Darcy A. A. Taniguchi
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Building 54-1511A, Cambridge, MA 02142, USA
| | - Alain De Verneil
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
| | - Michael R. Landry
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
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Goes JI, Gomes HDR, Selph KE, Landry MR. Biological response of Costa Rica Dome phytoplankton to Light, Silicic acid and Trace metals. J Plankton Res 2016; 38:290-304. [PMID: 27275031 PMCID: PMC4889990 DOI: 10.1093/plankt/fbv108] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Accepted: 11/19/2015] [Indexed: 05/25/2023]
Abstract
The Costa Rica Dome (CRD) is a unique open-ocean upwelling system, with picophytoplankton dominance of phytoplankton biomass and suppressed diatoms, yet paradoxically high export of biogenic silica. As a part of Flux and Zinc Experiments cruise in summer (June-July 2010), we conducted shipboard incubation experiments in the CRD to examine the potential roles of Si, Zn, Fe and light as regulating factors of phytoplankton biomass and community structure. Estimates of photosynthetic quantum yields revealed an extremely stressed phytoplankton population that responded positively to additions of silicic acid, iron and zinc and higher light conditions. Size-fractioned Chl a yielded the surprising result that picophytoplankton, as well as larger phytoplankton, responded most to treatments with added silicic acid incubated at high incident light (HL + Si). The combination of Si and HL also led to increases in cell sizes of picoplankton, notably in Synechococcus. Such a response, coupled with the recent discovery of significant intracellular accumulation of Si in some picophytoplankton, suggests that small phytoplankton could play a potentially important role in Si cycling in the CRD, which may help to explain its peculiar export characteristics.
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Affiliation(s)
- Joaquim I. Goes
- Lamont Doherty Earth Observatory at Columbia University, Palisades, New York, NY 10964, USA
| | - Helga do Rosario Gomes
- Lamont Doherty Earth Observatory at Columbia University, Palisades, New York, NY 10964, USA
| | - Karen E. Selph
- Department of Oceanography, University of Hawaii at Manoa, Honululu, HI 96822, USA
| | - Michael R. Landry
- Scripps Institution of Oceanography, University of California at San Diego, 9500 Gilman Dr, La Jolla, CA 92093, USA
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18
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Stukel MR, Benitez-Nelson CR, Décima M, Taylor AG, Buchwald C, Landry MR. The biological pump in the Costa Rica Dome: an open-ocean upwelling system with high new production and low export. J Plankton Res 2016; 38:348-365. [PMID: 27275035 PMCID: PMC4889986 DOI: 10.1093/plankt/fbv097] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 10/25/2015] [Indexed: 05/31/2023]
Abstract
The Costa Rica Dome is a picophytoplankton-dominated, open-ocean upwelling system in the Eastern Tropical Pacific that overlies the ocean's largest oxygen minimum zone. To investigate the efficiency of the biological pump in this unique area, we used shallow (90-150 m) drifting sediment traps and 234Th:238U deficiency measurements to determine export fluxes of carbon, nitrogen and phosphorus in sinking particles. Simultaneous measurements of nitrate uptake and shallow water nitrification allowed us to assess the equilibrium balance of new and export production over a monthly timescale. While f-ratios (new:total production) were reasonably high (0.36 ± 0.12, mean ± standard deviation), export efficiencies were considerably lower. Sediment traps suggested e-ratios (export/14C-primary production) at 90-100 m ranging from 0.053 to 0.067. ThE-ratios (234Th disequilibrium-derived export) ranged from 0.038 to 0.088. C:N and N:P stoichiometries of sinking material were both greater than canonical (Redfield) ratios or measured C:N of suspended particulates, and they increased with depth, suggesting that both nitrogen and phosphorus were preferentially remineralized from sinking particles. Our results are consistent with an ecosystem in which mesozooplankton play a major role in energy transfer to higher trophic levels but are relatively inefficient in mediating vertical carbon flux to depth, leading to an imbalance between new production and sinking flux.
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Affiliation(s)
- Michael R. Stukel
- Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL 32306, USA
| | - Claudia R. Benitez-Nelson
- Marine Science Program and Department of Earth and Ocean Sciences, University of South Carolina, Columbia, SC 29208, USA
| | - Moira Décima
- Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA 92037, USA
- National Institute of Water and Atmospheric Research (NIWA), 301 Evans Bay Parade, Hataitai 6021, Wellington, New Zealand
| | - Andrew G. Taylor
- Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA 92037, USA
| | | | - Michael R. Landry
- Scripps Institution of Oceanography, University of California at San Diego, La Jolla, CA 92037, USA
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Dreux Chappell P, Vedmati J, Selph KE, Cyr HA, Jenkins BD, Landry MR, Moffett JW. Preferential depletion of zinc within Costa Rica upwelling dome creates conditions for zinc co-limitation of primary production. J Plankton Res 2016; 38:244-255. [PMID: 27275028 PMCID: PMC4889994 DOI: 10.1093/plankt/fbw018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 02/04/2016] [Indexed: 05/25/2023]
Abstract
The Costa Rica Dome (CRD) is a wind-driven feature characterized by high primary production and an unusual cyanobacterial bloom in surface waters. It is not clear whether this bloom arises from top-down or bottom-up processes. Several studies have argued that trace metal geochemistry within the CRD contributes to the composition of the phytoplankton assemblages, since cyanobacteria and eukaryotic phytoplankton have different transition metal requirements. Here, we report that total dissolved zinc (Zn) is significantly depleted relative to phosphate (P) and silicate (Si) within the upper water column of the CRD compared with other oceanic systems, and this may create conditions favorable for cyanobacteria, which have lower Zn requirements than their eukaryotic competitors. Shipboard grow-out experiments revealed that while Si was a limiting factor under our experimental conditions, additions of Si and either iron (Fe) or Zn led to higher biomass than Si additions alone. The addition of Fe and Zn alone did not lead to significant enhancements. Our results suggest that the depletion of Zn relative to P in upwelled waters may create conditions in the near-surface waters that favor phytoplankton with low Zn requirements, including cyanobacteria.
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Affiliation(s)
- P. Dreux Chappell
- Department of Cell and Molecular Biology, University of Rhode Island, Kingston, RI 02881, USA
- Department of Ocean, Earth, and Atmospheric Sciences, Old Dominion University, Norfolk, VA 23529, USA
| | - Jagruti Vedmati
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Karen E. Selph
- Department of Oceanography, University of Hawaii at Manoa, Honolulu, HI 96822, USA
| | - Heather A. Cyr
- Department of Cell and Molecular Biology, University of Rhode Island, Kingston, RI 02881, USA
| | - Bethany D. Jenkins
- Department of Cell and Molecular Biology, University of Rhode Island, Kingston, RI 02881, USA
| | - Michael R. Landry
- Scripps Institution of Oceanography, University of California at San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
| | - James W. Moffett
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
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Landry MR, Selph KE, Décima M, Gutiérrez-Rodríguez A, Stukel MR, Taylor AG, Pasulka AL. Phytoplankton production and grazing balances in the Costa Rica Dome. J Plankton Res 2016; 38:366-379. [PMID: 27275036 PMCID: PMC4889984 DOI: 10.1093/plankt/fbv089] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Accepted: 09/15/2015] [Indexed: 05/10/2023]
Abstract
We investigated phytoplankton production rates and grazing fates in the Costa Rica Dome (CRD) during summer 2010 based on dilution depth profiles analyzed by flow cytometry and pigments and mesozooplankton grazing assessed by gut fluorescence. Three community production estimates, from 14C uptake (1025 ± 113 mg C m-2 day-1) and from dilution experiments analyzed for total Chla (990 ± 106 mg C m-2 day-1) and flow cytometry populations (862 ± 71 mg C m-2 day-1), exceeded regional ship-based values by 2-3-fold. Picophytoplankton accounted for 56% of community biomass and 39% of production. Production profiles extended deeper for Prochlorococcus (PRO) and picoeukaryotes than for Synechococcus (SYN) and larger eukaryotes, but 93% of total production occurred above 40 m. Microzooplankton consumed all PRO and SYN growth and two-third of total production. Positive net growth of larger eukaryotes in the upper 40 m was balanced by independently measured consumption by mesozooplankton. Among larger eukaryotes, diatoms contributed ∼3% to production. On the basis of this analysis, the CRD region is characterized by high production and grazing turnover, comparable with or higher than estimates for the eastern equatorial Pacific. The region nonetheless displays characteristics atypical of high productivity, such as picophytoplankton dominance and suppressed diatom roles.
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Affiliation(s)
- Michael R. Landry
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
- corresponding author:
| | - Karen E. Selph
- Department of Oceanography, University of Hawaii at Manoa, Honolulu, HI 96822, USA
| | - Moira Décima
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
- National Institute of Water and Atmospheric Research (NIWA), 301 Evans Bay Parade, Hataitai, Wellington 6021, New Zealand
| | - Andrés Gutiérrez-Rodríguez
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
- Centre National de la Recherche Scientifique and Universite Pierre et Marie Curie, Station Biologique, Roscoff 29680, France
| | - Michael R. Stukel
- Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL 32306, USA
| | - Andrew G. Taylor
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
| | - Alexis L. Pasulka
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
- Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
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Décima M, Landry MR, Stukel MR, Lopez-Lopez L, Krause JW. Mesozooplankton biomass and grazing in the Costa Rica Dome: amplifying variability through the plankton food web. J Plankton Res 2016; 38:317-330. [PMID: 27275033 PMCID: PMC4889985 DOI: 10.1093/plankt/fbv091] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 09/24/2015] [Indexed: 05/25/2023]
Abstract
We investigated standing stocks and grazing rates of mesozooplankton assemblages in the Costa Rica Dome (CRD), an open-ocean upwelling ecosystem in the eastern tropical Pacific. While phytoplankton biomass in the CRD is dominated by picophytoplankton (<2-µm cells) with especially high concentrations of Synechococcus spp., we found high mesozooplankton biomass (∼5 g dry weight m-2) and grazing impact (12-50% integrated water column chlorophyll a), indicative of efficient food web transfer from primary producers to higher levels. In contrast to the relative uniformity in water-column chlorophyll a and mesozooplankton biomass, variability in herbivory was substantial, with lower rates in the central dome region and higher rates in areas offset from the dome center. While grazing rates were unrelated to total phytoplankton, correlations with cyanobacteria (negative) and biogenic SiO2 production (positive) suggest that partitioning of primary production among phytoplankton sizes contributes to the variability observed in mesozooplankton metrics. We propose that advection of upwelled waters away from the dome center is accompanied by changes in mesozooplankton composition and grazing rates, reflecting small changes within the primary producers. Small changes within the phytoplankton community resulting in large changes in the mesozooplankton suggest that the variability in lower trophic level dynamics was effectively amplified through the food web.
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Affiliation(s)
- Moira Décima
- Scripps Institution of Oceanography, 9500 Gilman Dr., LA Jolla, CA 92093-0227, USA; Present Address: National Institute of Water and Atmospheric Research (NIWA), 301 Evans Bay Parade, Hataitai 6021, Wellington, New Zealand
| | - Michael R Landry
- Scripps Institution of Oceanography , 9500 Gilman Dr., LA Jolla, CA 92093-0227 , USA
| | - Michael R Stukel
- Department of Earth, Ocean, and Atmospheri Science , Florida State University , Tallahasee, FL 32306 , USA
| | - Lucia Lopez-Lopez
- Ieo Centro Oceanografico De Santander , Promontorio San Martin S/N, 39004 Santander-Cantabria , Spain
| | - Jeffrey W Krause
- Dauphin Island Sea Lab , 101 Bienville Blvd, Dauphin Island, AL 36528 , USA
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Baines SB, Chen X, Twining BS, Fisher NS, Landry MR. Factors affecting Fe and Zn contents of mesozooplankton from the Costa Rica Dome. J Plankton Res 2016; 38:331-347. [PMID: 27275034 PMCID: PMC4889987 DOI: 10.1093/plankt/fbv098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 10/22/2015] [Indexed: 05/10/2023]
Abstract
Mineral limitation of mesozooplankton production is possible in waters with low trace metal availability. As a step toward estimating mesozooplankton Fe and Zn requirements under such conditions, we measured tissue concentrations of major and trace nutrient elements within size-fractioned zooplankton samples collected in and around the Costa Rica Upwelling Dome, a region where phytoplankton growth may be co-limited by Zn and Fe. The geometric mean C, N, P contents were 27, 5.6 and 0.21 mmol gdw-1, respectively. The values for Fe and Zn were 1230 and 498 nmol gdw-1, respectively, which are low compared with previous measurements. Migrant zooplankton caused C and P contents of the 2-5 mm fraction to increase at night relative to the day while the Fe and Zn contents decreased. Fe content increased with size while Zn content decreased with size. Fe content was strongly correlated to concentrations of two lithogenic tracers, Al and Ti. We estimate minimum Fe:C ratios in large migrant and resident mixed layer zooplankton to be 15 and 60 µmol mol-1, respectively. The ratio of Zn:C ranged from 11 µmol mol-1 for the 0.2-0.5 mm size fraction to 33 µmol mol-1 for the 2-5 mm size fraction.
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Affiliation(s)
- Stephen B. Baines
- Department of Ecology and Evolution, Stony Brook University, Stony Brook, NY 11789-5245, USA
- corresponding author:
| | - Xi Chen
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11789-5000, USA
| | | | - Nicholas S. Fisher
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11789-5000, USA
| | - Michael R. Landry
- Scripps Institution of Oceanography, University of California at San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
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Landry MR, De Verneil A, Goes JI, Moffett JW. Plankton dynamics and biogeochemical fluxes in the Costa Rica Dome: introduction to the CRD Flux and Zinc Experiments. J Plankton Res 2016; 38:167-182. [PMID: 27275023 PMCID: PMC4889988 DOI: 10.1093/plankt/fbv103] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Accepted: 11/09/2015] [Indexed: 05/25/2023]
Abstract
The Costa Rica Dome (CRD) is an open-ocean upwelling system in the Eastern Tropical Pacific that overlies the ocean's largest oxygen minimum zone (OMZ). The region has unique characteristics, biomass dominance by picophytoplankton, suppressed diatoms, high biomass of higher consumers and presumptive trace metal limitation, but is poorly understood in terms of pelagic stock and process relationships, including productivity and production controls. Here, we describe the goals, project design, physical context and major findings of the Flux and Zinc Experiments cruise conducted in June-July 2010 to assess trophic flux relationships and elemental controls on phytoplankton in the CRD. Despite sampling during a year of suppressed summertime surface chlorophyll, cruise results show high productivity (∼1 g C m-2 day-1), high new production relative to export, balanced production and grazing, disproportionate biomass-specific productivity of large phytoplankton and high zooplankton stocks. Zinc concentrations are low in surface waters relative to phosphorous and silicate in other regions, providing conditions conducive to picophytoplankton, like Synechococcus, with low Zn requirements. Experiments nonetheless highlight phytoplankton limitation or co-limitation by silicic acid, driven by a strong silica pump that is linked to low dissolution of biogenic silica in the cold shallow thermocline of the lower euphotic zone.
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Affiliation(s)
- Michael R Landry
- Scripps Institution of Oceanography, University of California at San Diego , 9500 Gilman Dr., La Jolla, CA 92093-0227 , USA
| | - Alain De Verneil
- Scripps Institution of Oceanography, University of California at San Diego , 9500 Gilman Dr., La Jolla, CA 92093-0227 , USA
| | - Joaquim I Goes
- Department of Marine Biology and Paleoenvironment , Lamont Doherty Earth Observatory at Columbia University , Palisades, NY 10964 , USA
| | - James W Moffett
- Department of Biological Sciences , University of Southern California , Los Angeles, CA 90089 , USA
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Taylor AG, Landry MR, Freibott A, Selph KE, Gutiérrez-Rodríguez A. Patterns of microbial community biomass, composition and HPLC diagnostic pigments in the Costa Rica upwelling dome. J Plankton Res 2016; 38:183-198. [PMID: 27275024 PMCID: PMC4889983 DOI: 10.1093/plankt/fbv086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Accepted: 09/10/2015] [Indexed: 05/10/2023]
Abstract
We investigated biomass, size-structure, composition, depth distributions and spatial variability of the phytoplankton community in the Costa Rica Dome (CRD) in June-July 2010. Euphotic zone profiles were sampled daily during Lagrangian experiments in and out of the dome region, and the community was analyzed using a combination of digital epifluorescence microscopy, flow cytometry and HPLC pigments. The mean depth-integrated biomass of phytoplankton ranged 2-fold, from 1089 to 1858 mg C m-2 (mean ± SE = 1378 ± 112 mg C m-2), among 4 water parcels tracked for 4 days. Corresponding mean (±SE) integrated values for total chlorophyll a (Chl a) and the ratio of autotrophic carbon to Chl a were 24.1 ± 1.5 mg Chl a m-2 and 57.5 ± 3.4, respectively. Absolute and relative contributions of picophytoplankton (∼60%), Synechococcus (>33%) and Prochlorococcus (17%) to phytoplankton community biomass were highest in the central dome region, while >20 µm phytoplankton accounted for ≤10%, and diatoms <2%, of biomass in all areas. Nonetheless, autotrophic flagellates, dominated by dinoflagellates, exceeded biomass contributions of Synechococcus at all locations. Order-of-magnitude discrepancies in the relative contributions of diatoms (overestimated) and dinoflagellates (underestimated) based on diagnostic pigments relative to microscopy highlight potential significant biases associated with making community inferences from pigments.
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Affiliation(s)
- Andrew G. Taylor
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
| | - Michael R. Landry
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
- corresponding author:
| | - Alexandra Freibott
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
| | - Karen E. Selph
- Department of Oceanography, University of Hawaii At Manoa, Honolulu, HI 96822, USA
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Pasulka AL, Levin LA, Steele JA, Case DH, Landry MR, Orphan VJ. Microbial eukaryotic distributions and diversity patterns in a deep-sea methane seep ecosystem. Environ Microbiol 2016; 18:3022-43. [PMID: 26663587 DOI: 10.1111/1462-2920.13185] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 12/03/2015] [Accepted: 12/08/2015] [Indexed: 11/30/2022]
Abstract
Although chemosynthetic ecosystems are known to support diverse assemblages of microorganisms, the ecological and environmental factors that structure microbial eukaryotes (heterotrophic protists and fungi) are poorly characterized. In this study, we examined the geographic, geochemical and ecological factors that influence microbial eukaryotic composition and distribution patterns within Hydrate Ridge, a methane seep ecosystem off the coast of Oregon using a combination of high-throughput 18S rRNA tag sequencing, terminal restriction fragment length polymorphism fingerprinting, and cloning and sequencing of full-length 18S rRNA genes. Microbial eukaryotic composition and diversity varied as a function of substrate (carbonate versus sediment), activity (low activity versus active seep sites), sulfide concentration, and region (North versus South Hydrate Ridge). Sulfide concentration was correlated with changes in microbial eukaryotic composition and richness. This work also revealed the influence of oxygen content in the overlying water column and water depth on microbial eukaryotic composition and diversity, and identified distinct patterns from those previously observed for bacteria, archaea and macrofauna in methane seep ecosystems. Characterizing the structure of microbial eukaryotic communities in response to environmental variability is a key step towards understanding if and how microbial eukaryotes influence seep ecosystem structure and function.
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Affiliation(s)
- Alexis L Pasulka
- Integrative Oceanography Division and Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California, San Diego, CA, USA. .,Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA.
| | - Lisa A Levin
- Integrative Oceanography Division and Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California, San Diego, CA, USA
| | - Josh A Steele
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA.,Southern California Coastal Water Research Project, Costa Mesa, CA, USA
| | - David H Case
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
| | - Michael R Landry
- Integrative Oceanography Division and Center for Marine Biodiversity and Conservation, Scripps Institution of Oceanography, University of California, San Diego, CA, USA
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
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Macias D, Landry MR, Gershunov A, Miller AJ, Franks PJS. Climatic control of upwelling variability along the western North-American coast. PLoS One 2012; 7:e30436. [PMID: 22276199 PMCID: PMC3261912 DOI: 10.1371/journal.pone.0030436] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Accepted: 12/20/2011] [Indexed: 11/29/2022] Open
Abstract
The high biological production of the California Current System (CCS) results from the seasonal development of equatorward alongshore winds that drive coastal upwelling. While several climatic fluctuation patterns influence the dynamics and biological productivity of the CCS, including the El Niño-Southern Oscillation (ENSO), the Pacific Decadal Oscillation index (PDO) and the North Pacific Gyre Oscillation (NPGO), the mechanisms of interaction between climatic oscillations and the CCS upwelling dynamics have remained obscure. Here, we use Singular Spectral Analysis (SSA) to reveal, for the first time, low-frequency concordance between the time series of climatic indices and upwelling intensity along the coast of western North America. Based on energy distributions in annual, semiannual and low-frequency signals, we can divide the coast into three distinct regions. While the annual upwelling signal dominates the energy spectrum elsewhere, low-frequency variability is maximal in the regions south of 33°N. Non-structured variability associated with storms and turbulent mixing is enhanced at northerly locations. We found that the low-frequency signal is significantly correlated with different climatic indices such as PDO, NPGO and ENSO with the correlation patterns being latitude-dependent. We also analyzed the correlations between this upwelling variability and sea surface temperature (SST) and sea level pressure (SLP) throughout the North Pacific to visualize and interpret the large-scale teleconnection dynamics in the atmosphere that drive the low-frequency coastal winds. These results provide new insights into the underlying mechanisms connecting climatic patterns with upwelling dynamics, which could enhance our prediction and forecast capabilities of the effects of future oceanographic and climatic variability in the CCS.
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Affiliation(s)
- Diego Macias
- Department of Ecology and Coastal Management, Instituto de Ciencias Marinas de Andalucía, Consejo Superior de Investigaciones Científicas, Puerto Real, Cadiz, Spain.
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Li QP, Franks PJS, Landry MR, Goericke R, Taylor AG. Modeling phytoplankton growth rates and chlorophyll to carbon ratios in California coastal and pelagic ecosystems. ACTA ACUST UNITED AC 2010. [DOI: 10.1029/2009jg001111] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
We investigated the accuracy and precision of flow cytometric (FCM) estimates of bacterial abundances using 4', 6-diamidino-2-phenylindole (DAPI) and Hoechst 33342 (HO342, a bisbenzamide derivative) on paraformaldehyde-fixed seawater samples collected from two stations near Oahu, Hawaii. The accuracy of FCM estimates was assessed against direct counts by using epifluorescence microscopy. DAPI and HO342 differ in two aspects of their chemistry that make HO342 better suited for staining marine heterotrophic bacteria for FCM analysis. These differences are most important in studies of open-ocean ecosystems that require dual-beam FCM analysis to clearly separate heterotrophic bacterial populations from populations of photosynthetic Prochlorococcus spp. Bacterial populations were easier to distinguish from background fluorescence when stained with HO342 than when stained with DAPI, because HO342 has a higher relative fluorescence quantum yield. A substantially higher coefficient of variation of blue fluorescence, which was probably due to fluorescent complexes formed by DAPI with double-stranded RNA, was observed for DAPI-stained populations. FCM estimates averaged 2.0 and 12% higher than corresponding epifluorescence microscopy direct counts for HO342 and DAPI-stained samples, respectively. A paired-sample t test between FCM estimates and direct counts found no significant difference for HO342-stained samples but a significant difference for DAPI-stained samples. Coefficients of variation of replicate FCM abundance estimates ranged from 0.63 to 2.9% (average, 1.5%) for natural bacterial concentrations of 6 x 10 to 15 x 10 cells ml.
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Affiliation(s)
- B C Monger
- Department of Oceanography, School of Ocean and Earth Science and Technology, University of Hawaii at Manoa, Honolulu, Hawaii 96822
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Coale KH, Johnson KS, Fitzwater SE, Gordon RM, Tanner S, Chavez FP, Ferioli L, Sakamoto C, Rogers P, Millero F, Steinberg P, Nightingale P, Cooper D, Cochlan WP, Landry MR, Constantinou J, Rollwagen G, Trasvina A, Kudela R. A massive phytoplankton bloom induced by an ecosystem-scale iron fertilization experiment in the equatorial Pacific Ocean. Nature 2008; 383:495 - 501. [PMID: 18680864 DOI: 10.1038/383495a0] [Citation(s) in RCA: 316] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The seeding of an expanse of surface waters in the equatorial Pacific Ocean with low concentrations of dissolved iron triggered a massive phytoplankton bloom which consumed large quantities of carbon dioxide and nitrate that these microscopic plants cannot fully utilize under natural conditions. These and other observations provide unequivocal support for the hypothesis that phytoplankton growth in this oceanic region is limited by iron bioavailability.
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Benitez-Nelson CR, Bidigare RR, Dickey TD, Landry MR, Leonard CL, Brown SL, Nencioli F, Rii YM, Maiti K, Becker JW, Bibby TS, Black W, Cai WJ, Carlson CA, Chen F, Kuwahara VS, Mahaffey C, McAndrew PM, Quay PD, Rappé MS, Selph KE, Simmons MP, Yang EJ. Mesoscale Eddies Drive Increased Silica Export in the Subtropical Pacific Ocean. Science 2007; 316:1017-21. [PMID: 17510362 DOI: 10.1126/science.1136221] [Citation(s) in RCA: 200] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Mesoscale eddies may play a critical role in ocean biogeochemistry by increasing nutrient supply, primary production, and efficiency of the biological pump, that is, the ratio of carbon export to primary production in otherwise nutrient-deficient waters. We examined a diatom bloom within a cold-core cyclonic eddy off Hawaii. Eddy primary production, community biomass, and size composition were markedly enhanced but had little effect on the carbon export ratio. Instead, the system functioned as a selective silica pump. Strong trophic coupling and inefficient organic export may be general characteristics of community perturbation responses in the warm waters of the Pacific Ocean.
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Affiliation(s)
- Claudia R Benitez-Nelson
- Department of Geological Sciences and Marine Science Program, University of South Carolina, Columbia, SC 29208, USA.
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Coale KH, Johnson KS, Chavez FP, Buesseler KO, Barber RT, Brzezinski MA, Cochlan WP, Millero FJ, Falkowski PG, Bauer JE, Wanninkhof RH, Kudela RM, Altabet MA, Hales BE, Takahashi T, Landry MR, Bidigare RR, Wang X, Chase Z, Strutton PG, Friederich GE, Gorbunov MY, Lance VP, Hilting AK, Hiscock MR, Demarest M, Hiscock WT, Sullivan KF, Tanner SJ, Gordon RM, Hunter CN, Elrod VA, Fitzwater SE, Jones JL, Tozzi S, Koblizek M, Roberts AE, Herndon J, Brewster J, Ladizinsky N, Smith G, Cooper D, Timothy D, Brown SL, Selph KE, Sheridan CC, Twining BS, Johnson ZI. Southern Ocean Iron Enrichment Experiment: Carbon Cycling in High- and Low-Si Waters. Science 2004; 304:408-14. [PMID: 15087542 DOI: 10.1126/science.1089778] [Citation(s) in RCA: 465] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The availability of iron is known to exert a controlling influence on biological productivity in surface waters over large areas of the ocean and may have been an important factor in the variation of the concentration of atmospheric carbon dioxide over glacial cycles. The effect of iron in the Southern Ocean is particularly important because of its large area and abundant nitrate, yet iron-enhanced growth of phytoplankton may be differentially expressed between waters with high silicic acid in the south and low silicic acid in the north, where diatom growth may be limited by both silicic acid and iron. Two mesoscale experiments, designed to investigate the effects of iron enrichment in regions with high and low concentrations of silicic acid, were performed in the Southern Ocean. These experiments demonstrate iron's pivotal role in controlling carbon uptake and regulating atmospheric partial pressure of carbon dioxide.
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Affiliation(s)
- Kenneth H Coale
- Moss Landing Marine Laboratories, 8272 Moss Landing Road, Moss Landing, CA 95039-9647, USA.
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Landry MR. Phytoplankton growth and microzooplankton grazing in high-nutrient, low-chlorophyll waters of the equatorial Pacific: Community and taxon-specific rate assessments from pigment and flow cytometric analyses. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2000jc000744] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Nemoto N, Landry MR, Noh I, Kitano T, Wesson JA, Yu H. Concentration dependence of self-diffusion coefficient by forced Rayleigh scattering: polystyrene in tetrahydrofuran. Macromolecules 2002. [DOI: 10.1021/ma00144a038] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Landry CJT, Coltrain BK, Landry MR, Fitzgerald JJ, Long VK. Poly(vinyl acetate)/silica-filled materials: material properties of in situ vs fumed silica particles. Macromolecules 2002. [DOI: 10.1021/ma00066a032] [Citation(s) in RCA: 171] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Landry CJT, Massa DJ, Teegarden DM, Landry MR, Henrichs PM, Colby RH, Long TE. Miscibility in binary blends of poly(vinylphenol) and aromatic polyesters. Macromolecules 2002. [DOI: 10.1021/ma00075a027] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Landry MR, Brown SL, Selph KE, Abbott MR, Letelier RM, Christensen S, Bidigare RR, Casciotti K. Initiation of the spring phytoplankton increase in the Antarctic Polar Front zone at 170°W. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/1999jc000187] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Brown SL, Landry MR. Mesoscale variability in biological community structure and biomass in the Antarctic Polar Front region at 170°W during austral spring 1997. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/1999jc000188] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Liu H, Landry MR, Vaulot D, Campbell L. Prochlorococcusgrowth rates in the central equatorial Pacific: An application of the ƒmaxapproach. ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1998jc900011] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Chung SP, Gardner WD, Landry MR, Richardson MJ, Walsh ID. Beam attenuation by microorganisms and detrital particles in the equatorial Pacific. ACTA ACUST UNITED AC 1998. [DOI: 10.1029/98jc00608] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Affiliation(s)
- Michael R. Landry
- Imaging Research and Advanced Development, Eastman Kodak Company, Rochester, New York 14650-2132
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Affiliation(s)
- Nicholas Zumbulyadis
- Analytical Technology Division, Eastman Kodak Company, Rochester, New York 14650-2132
| | - Michael R. Landry
- Analytical Technology Division, Eastman Kodak Company, Rochester, New York 14650-2132
| | - Thomas P. Russell
- Almaden Research Center, IBM Research Division, 650 Harry Road, San Jose, California 95120-6099
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Landry MR, Coltrain BK, Landry CJT, O'Reilly JM. Structural models for homogeneous organic-inorganic hybrid materials: Simulations of small-angle X-ray scattering profiles. ACTA ACUST UNITED AC 1995. [DOI: 10.1002/polb.1995.090330414] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Abstract
A novel method for quantifying chemiluminescent DNA probes is described. The method uses liquid scintillation counting to measure light emission from the alkaline phosphatase-catalyzed breakdown of the substrate PPD (3-(4-methoxyspiro[1,2-dioxetane-3,2'-tricyclo[3.3.1.1 (3.7[decan]- 4-yl)phenyl phosphate) on dot blot preparations. Serial dilutions of either pUC18 DNA or lambda DNA were hybridized with digoxigenin-labeled probes and detected using the method described. Light flux (luminescence) was linearly related to DNA concentration, typically with a coefficient of determination (r2) of 0.9 or better. Due to the stability of alkaline phosphatase and the long-lived luminescence of PPD in the Lumi-phos formulation, repetitive analyses of a given sample can be made for up to 20 h. The method can reliably detect 17 amol of DNA (30 pg pUC18DNA) with a coefficient of variation on replicate samples of 14%. Optimization experiments showed that 7% sodium dodecyl sulfate in the prehybridization and hybridization buffers resulted in the lowest background; the best combination of signal-to-noise ratio and reproducibility was obtained using Bio-Rad Zeta-Probe GT nylon membranes. Direct immersion of samples into a solution of substrate was found to give the most precise results and ensured that substrate limitation at high concentrations of alkaline phosphatase (i.e., higher DNA amounts) did not occur.
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Affiliation(s)
- K E Selph
- School of Ocean and Earth Science and Technology, Department of Oceanography, University of Hawaii, Manoa, Honolulu 96822
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Fitzgerald JJ, Tunney SE, Landry MR. Synthesis and characterization of a fluorinated poly(imide-siloxane) copolymer: a study of physical properties and morphology. POLYMER 1993. [DOI: 10.1016/0032-3861(93)90423-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Jackson GA, Azam F, Carlucci AF, Eppley RW, Williams PM, Finney B, Chih-An H, Small LF, Gorsline DS, Hickey B, Jahnke RA, Kaplan IR, Venkatesan MI, Landry MR, Wong KM. Elemental cycling and fluxes off southern California. ACTA ACUST UNITED AC 1989. [DOI: 10.1029/89eo00082] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Landry MR. Population Dynamics and Production of a Planktonic Marine Copepod,. Acartia clausii, in a Small Temperate Lagoon on San Juan Island, Washington. ACTA ACUST UNITED AC 1978. [DOI: 10.1002/iroh.19780630106] [Citation(s) in RCA: 137] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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