Ch. 9: Ocean Biogeochemistry

Total Page:16

File Type:pdf, Size:1020Kb

Ch. 9: Ocean Biogeochemistry 6/3/13 Ch. 9: Ocean Biogeochemistry NOAA photo gallery Overview • The Big Picture • Ocean Circulation • Seawater Composition • Marine NPP • Particle Flux: The Biological Pump • Carbon Cycling • Nutrient Cycling • Time Pemitting: Hydrothermal venting, Sulfur cycling, Sedimentary record, El Niño • Putting It All Together Slides borrowed from Aradhna Tripati 1 6/3/13 Ocean Circulation • Upper Ocean is wind-driven and well mixed • Surface Currents deflected towards the poles by land. • Coriolis force deflects currents away from the wind, forming mid-ocean gyres • Circulation moves heat poleward • River influx is to surface ocean • Atmospheric equilibrium is with surface ocean • Primary productivity is in the surface ocean Surface Currents 2 6/3/13 Deep Ocean Circulation • Deep and Surface Oceans separated by density gradient caused by differences in Temperature and Salinity • This drives thermohaline deep circulation: * Ice forms in the N. Atlantic and Southern Ocean, leaving behind cold, saline water which sinks * Oldest water is in N. Pacific * Distribution of dissolved gases and nutrients: N, P, CO2 Seawater Composition • Salinity is defined as grams of salt/kg seawater, or parts per thousand: %o • Major ions are in approximately constant concentrations everywhere in the oceans • Salts enter in river water, and are removed by porewater burial, sea spray and evaporites (Na, Cl). • Calcium and Sulfate are removed in biogenic sediments • Magnesium is consumed in hydrothermal vents, in ionic exchange for Ca in rock. • Potassium adsorbs in clays. 3 6/3/13 Major Ions in Seawater The Two-Box Model of the Ocean Precipitation Evaporation River Flow Upwelling Downwelling Particle Flux Sedimentation 4 6/3/13 Residence time vs. chemistry Marine Primary Production • Marine NPP occurs in the top 200 meters of the ocean • Difficult to measure • Estimates range from 27-50 Pg C/year (50 x 1015g C/yr) • Trophic cycling: single-celled phytoplankton, zooplankton, bacteria • Recycling of dissolved organic material (DOM) retains nutrients in the upper ocean in particulate form • Some particulate organic matter sinks out of upper ocean • Important sink for Carbon cycle: “Biological Pump” 5 6/3/13 Marine Primary Production Marine Primary Production 6 6/3/13 Decomposition/breakdown of organic C Particle Flux • Marine snow: sinking particles composed of living and dead organisms, fecal pellets: a constant, slow rain • Bacterial decomposition (respiration) continues through the entire depth of the water-column remineralizing organic material • Less than 1% of NPP actually makes it to the bottom to be buried in sediments (Estimated at 0.157 Pg C/yr) • Diagenesis in near-shore organic sediments: * Sulfate reduction ⇒ Pyrite formation * Methanogenesis 7 6/3/13 Carbon Sedimentation • Some organisms form carbonate shells or tests • These may be deposited as sediments in particle flux, or they may dissolve: 2+ 2- CaCO3 + H2O ⇒ Ca + CO3 • Calcium carbonate dissolves better in colder water / higher pressures: deep ocean conditions. • CaCO3 deposits on Continental shelves, Mid-ocean ridges, island flanks • No Deep Ocean deposition Carbonate Compensation Depth • CO2 equilibrates between surface ocean and atmosphere in accordance with Henry’s Law • In seawater, CO2 dissociates: + - + 2- CO2 + H2O ⇔ H2CO3 ⇔ H + HCO3 ⇔ H + CO3 2- • Supersaturation of CO3 in upper ocean prevents CaCO3 dissolution • Lysocline: dissolution rate increases rapidly with depth • CCD: The depth below which the calcium carbonate deposition drops below about 20% 8 6/3/13 Lysocline and CCD Carbonate Deposition 20 % 100% 4 km Depth Lysocline CCD 5 km Cycling of inorganic carbon (carbonate) 9 6/3/13 SeaWiFS website: NFS/NASA Nutrient Cycling • Near-surface levels of biolimiting nutrients are low: N & P • Increasing levels as sinking organic materials degraded • Remineralization increases concentration of dissolved nutrients • Strongly controlled by organisms: non-conservative • “Older” Pacific water has higher levels • Nutrients in upwelling water recharge surface ocean • Redfield Ratio in upwelling water similar to the ratio in organisms C : N : P 106 : 16 : 1 10 6/3/13 Depth Profiles of N and P 11 .
Recommended publications
  • Probing the Changing Redfield Ratio of Phytoplankton
    Probing the Changing Redfield Ratio of phytoplankton Supervisory Team Rosalind Rickaby www.earth.ox.ac.uk/people/rosalind-rickaby Katsumi Matsumoto www.esci.umn.edu/people/katsumi-matsumoto Key Research Question What controls the Redfield Ratio amongst algae? Overview under different conditions of Fe and C availability In 1934, Alfred Redfield made the notable to test the hypothesis that it is the nutrient observation that the relative ratios of C:N:P of efficiency of photosynthesis that dictates the C:N organic matter appeared to be constant throughout ratio of organic matter. the surface oceans, and also matched the Applicants would ideally have a background in dissolved ratios of those nutrients (C106N16P1). Biology/Chemistry/Earth Sciences or The Redfield ratio is fundamental in dictating the Environmental Sciences. strength of the biological sequestration of carbon, and the amount of oxygen that is used for respiration hence is an intimate control on the biotic feedback of phytoplankton on future climate. Despite efforts to understand the co-evolution of Methodology these ratios between the phytoplankton and the Methods to be used will include: Phytoplankton seawater from experimental, field observations Culture and sterile techniques, EA IRMS, and modelling efforts, there is still no mechanistic Spectrophotometry, and Microscopy. understanding of what drives the enormous variability seen across different phytoplankton lineages with various environmental conditions (Garcia et al., 2018). References & Further Reading Nature Geoscience
    [Show full text]
  • Methane Cold Seeps As Biological Oases in the High‐
    LIMNOLOGY and Limnol. Oceanogr. 00, 2017, 00–00 VC 2017 The Authors Limnology and Oceanography published by Wiley Periodicals, Inc. OCEANOGRAPHY on behalf of Association for the Sciences of Limnology and Oceanography doi: 10.1002/lno.10732 Methane cold seeps as biological oases in the high-Arctic deep sea Emmelie K. L. A˚ strom€ ,1* Michael L. Carroll,1,2 William G. Ambrose, Jr.,1,2,3,4 Arunima Sen,1 Anna Silyakova,1 JoLynn Carroll1,2 1CAGE - Centre for Arctic Gas Hydrate, Environment and Climate, Department of Geosciences, UiT The Arctic University of Norway, Tromsø, Norway 2Akvaplan-niva, FRAM – High North Research Centre for Climate and the Environment, Tromsø, Norway 3Division of Polar Programs, National Science Foundation, Arlington, Virginia 4Department of Biology, Bates College, Lewiston, Maine Abstract Cold seeps can support unique faunal communities via chemosynthetic interactions fueled by seabed emissions of hydrocarbons. Additionally, cold seeps can enhance habitat complexity at the deep seafloor through the accretion of methane derived authigenic carbonates (MDAC). We examined infaunal and mega- faunal community structure at high-Arctic cold seeps through analyses of benthic samples and seafloor pho- tographs from pockmarks exhibiting highly elevated methane concentrations in sediments and the water column at Vestnesa Ridge (VR), Svalbard (798 N). Infaunal biomass and abundance were five times higher, species richness was 2.5 times higher and diversity was 1.5 times higher at methane-rich Vestnesa compared to a nearby control region. Seabed photos reveal different faunal associations inside, at the edge, and outside Vestnesa pockmarks. Brittle stars were the most common megafauna occurring on the soft bottom plains out- side pockmarks.
    [Show full text]
  • Brochure.Pdf
    Two Little Fishies Two Little Fishies Inc. 4016 El Prado Blvd., Coconut Grove, Florida 33133 U.S.A. Tel (+01) 305 661.7742 Fax (+01) 305 661.0611 eMail: [email protected] ww w. t w o l i t t l e f i s h i e s . c o m © 2004 Two Little Fishies Inc. Two Little Fishies is a registered trademark of Two Little Fishies Inc.. All illustrations, photos and specifications contained in this broc h u r e are based on the latest pr oduct information available at the time of publication. Two Little Fishies Inc. res e r ves the right to make changes at any time, without notice. Printed in USA V.4 _ 2 0 0 4 Simple, Elegant, Practical,Solutions Useful... Two Little Fishies Two Little Fishies, Inc. was founded in 1991 to pr omote the reef aquarium hobby with its in t ro d u c t o r y video and books about ree f aquariums. The company now publishes and distributes the most popular reef aquarium ref e r ence books and identification guides in English, German French and Italian, under the d.b.a. Ricordea Publishing. Since its small beginning, Two Little Fishies has also grown to become a manufacturer and im p o r ter of the highest quality products for aquariums and water gardens, with interna t i o n a l distribution in the pet, aquaculture, and water ga r den industries. Two Little Fishies’ prod u c t line includes trace element supplements, calcium supplements and buffers, phosphate- fr ee activated carbon, granular iron - b a s e d phosphate adsorption media, underwa t e r bonding compounds, and specialty foods for fish and invertebrates.
    [Show full text]
  • Marine Microorganisms and Global Nutrient Cycles Kevin R
    03 Arrigo 15-21 6/9/05 11:17 AM Page 15 NATURE|Vol 437|15 September 2005|doi:10.1038/nature04158 INSIGHT REVIEW Marine microorganisms and global nutrient cycles Kevin R. Arrigo1 The way that nutrients cycle through atmospheric, terrestrial, oceanic and associated biotic reservoirs can constrain rates of biological production and help structure ecosystems on land and in the sea. On a global scale, cycling of nutrients also affects the concentration of atmospheric carbon dioxide. Because of their capacity for rapid growth, marine microorganisms are a major component of global nutrient cycles. Understanding what controls their distributions and their diverse suite of nutrient transformations is a major challenge facing contemporary biological oceanographers. What is emerging is an appreciation of the previously unknown degree of complexity within the marine microbial community. To understand how carbon and nutrients, such as nitrogen and phos- through the activities of marine phytoplankton. phorus, cycle through the atmosphere, land and oceans, we need a Unfortunately, a clear mechanism explaining the observed magni- clearer picture of the underlying processes. This is particularly impor- tude of the Redfield C:N:P ratio of 106:16:1 for either phytoplankton tant in the face of increasing anthropogenic nutrient release and or the deep ocean has been elusive. It has long been recognized that climate change. Marine microbes, which are responsible for approxi- conditions exist under which phytoplankton stoichiometry diverges mately half of the
    [Show full text]
  • Chapter 13 Lecture
    ChapterChapter 1 13 Clickers Lecture Essentials of Oceanography Eleventh Edition Biological Productivity and Energy Transfer Alan P. Trujillo Harold V. Thurman © 2014 Pearson Education, Inc. Chapter Overview • Primary productivity is photosynthesis. • Productivity is globally and seasonally variable. • Feeding relationships are represented by food chains and food webs. • Oceans are being overfished. © 2014 Pearson Education, Inc. Primary Productivity • Rate at which energy is stored in organic matter – Photosynthesis uses solar radiation. – Chemosynthesis uses chemical reactions. • 99.9% of the ocean’s biomass relies directly or indirectly on photosynthesis for food. © 2014 Pearson Education, Inc. Photosynthesis © 2014 Pearson Education, Inc. Measurement of Primary Productivity • Directly – capture plankton in plankton nets • Measure radioactive carbon in seawater © 2014 Pearson Education, Inc. Measurement of Primary Productivity • Monitor ocean color with satellites – Photosynthetic phytoplankton use green pigment chlorophyll • SeaWiFS (Sea-viewing Wide Field of View Sensor) satellite sensor collected ocean color data 1997–2010 • MODIS (Moderate Resolution Imaging Spectroradiometer) – current – Measures 36 spectral frequencies © 2014 Pearson Education, Inc. Factors Affecting Primary Productivity • Nutrient availability – Nitrate, phosphorous, iron, silica – Most from river runoff – Productivity high along continental margins – Redfield ratio – C:N:P © 2014 Pearson Education, Inc. Factors Affecting Primary Productivity • Solar radiation – Uppermost surface seawater and shallow seafloor – Compensation depth – net photosynthesis becomes zero – Euphotic zone —from surface to about 100 meters (330 feet) • Enough light for photosynthesis © 2014 Pearson Education, Inc. Light Transmission in Ocean Water • Visible light portion of the electromagnetic spectrum • Blue wavelengths penetrate deepest • Longer wavelengths (red, orange) absorbed first © 2014 Pearson Education, Inc. Transmission of Light in Seawater © 2014 Pearson Education, Inc.
    [Show full text]
  • Ocean Primary Production
    Learning Ocean Science through Ocean Exploration Section 6 Ocean Primary Production Photosynthesis very ecosystem requires an input of energy. The Esource varies with the system. In the majority of ocean ecosystems the source of energy is sunlight that drives photosynthesis done by micro- (phytoplankton) or macro- (seaweeds) algae, green plants, or photosynthetic blue-green or purple bacteria. These organisms produce ecosystem food that supports the food chain, hence they are referred to as primary producers. The balanced equation for photosynthesis that is correct, but seldom used, is 6CO2 + 12H2O = C6H12O6 + 6H2O + 6O2. Water appears on both sides of the equation because the water molecule is split, and new water molecules are made in the process. When the correct equation for photosynthe- sis is used, it is easier to see the similarities with chemo- synthesis in which water is also a product. Systems Lacking There are some ecosystems that depend on primary Primary Producers production from other ecosystems. Many streams have few primary producers and are dependent on the leaves from surrounding forests as a source of food that supports the stream food chain. Snow fields in the high mountains and sand dunes in the desert depend on food blown in from areas that support primary production. The oceans below the photic zone are a vast space, largely dependent on food from photosynthetic primary producers living in the sunlit waters above. Food sinks to the bottom in the form of dead organisms and bacteria. It is as small as marine snow—tiny clumps of bacteria and decomposing microalgae—and as large as an occasional bonanza—a dead whale.
    [Show full text]
  • Introduction to Marine Primary Productivity and Carbon Cycle
    Introduction to marine primary productivity and carbon cycle Satya Prakash [email protected] 400 Law Dome Ice Core, Antarctica 380 Mauna Loa, Hawaii Slope: 360 1970 - 1979: 1.3 ppm y-1 -1 340 2000 - 2006: 1.9 ppm y 320 Concentration (ppm) 2 CO 300 280 1820 1840 1860 1880 1900 1920 1940 1960 1980 2000 2020 Year CO2 – Temperature Relationship CO2 Concentration Temperature 380 4 2 340 0 300 -2 (ppmv) 2 260 -4 Degree C Degree CO -6 220 -8 180 -10 0 50 100 150 200 250 300 350 400 450 Age (Kyr) VOSTOK Ice Core data How much is 100 ppm?? 1 ppm = 2.12 * 1015 gm = 2.12*109 tonnes 100 ppm = 2.12 thousand crore tonnes 1m. 1m. = 1000 kg = 2.44 टन 1m. CO2 1m. Water or one tonne 1m. 1m. Partition of Anthropogenic Carbon Emissions into Sinks [2000-2006] 45% of all CO2 emissions accumulated in the atmosphere 55% were removed by natural sinks Ocean removes ~ 24% Land removes ~ 30% Upper Photic Layer Photosynthesis O2 O2 CO2 CO2 Respiration Deeper Aphotic Layer The Ocean Euphotic zone light - ~little N Aphotic zone no light - lots N Photosynthesis is a process that generates the organic matter in phytoplankton cells. The process of photosynthesis can be represented as: hv 106CO2 + 122H2O + 16HNO3 + H3PO4 (CH2O)106(NH3)16H3PO4 + 138O2 Available solar energy in the waveband 400-700 nm. This reaction illustrates the need for the nutrients: nitrate and phosphate. It also shows that for every 106 CO2 molecules taken up, approximately 138 O2 molecules are produced.
    [Show full text]
  • Eukaryotic Microbes, Principally Fungi and Labyrinthulomycetes, Dominate Biomass on Bathypelagic Marine Snow
    The ISME Journal (2017) 11, 362–373 © 2017 International Society for Microbial Ecology All rights reserved 1751-7362/17 www.nature.com/ismej ORIGINAL ARTICLE Eukaryotic microbes, principally fungi and labyrinthulomycetes, dominate biomass on bathypelagic marine snow Alexander B Bochdansky1, Melissa A Clouse1 and Gerhard J Herndl2 1Ocean, Earth and Atmospheric Sciences, Old Dominion University, Norfolk, VA, USA and 2Department of Limnology and Bio-Oceanography, Division of Bio-Oceanography, University of Vienna, Vienna, Austria In the bathypelagic realm of the ocean, the role of marine snow as a carbon and energy source for the deep-sea biota and as a potential hotspot of microbial diversity and activity has not received adequate attention. Here, we collected bathypelagic marine snow by gentle gravity filtration of sea water onto 30 μm filters from ~ 1000 to 3900 m to investigate the relative distribution of eukaryotic microbes. Compared with sediment traps that select for fast-sinking particles, this method collects particles unbiased by settling velocity. While prokaryotes numerically exceeded eukaryotes on marine snow, eukaryotic microbes belonging to two very distant branches of the eukaryote tree, the fungi and the labyrinthulomycetes, dominated overall biomass. Being tolerant to cold temperature and high hydrostatic pressure, these saprotrophic organisms have the potential to significantly contribute to the degradation of organic matter in the deep sea. Our results demonstrate that the community composition on bathypelagic marine snow differs greatly from that in the ambient water leading to wide ecological niche separation between the two environments. The ISME Journal (2017) 11, 362–373; doi:10.1038/ismej.2016.113; published online 20 September 2016 Introduction or dense phytodetritus, but a large amount of transparent exopolymer particles (TEP, Alldredge Deep-sea life is greatly dependent on the particulate et al., 1993), which led us to conclude that they organic matter (POM) flux from the euphotic layer.
    [Show full text]
  • A Review of the Methods and Metrics in Research, Implementation, and Management of Integrated Multi-Trophic Aquaculture
    The University of San Francisco USF Scholarship: a digital repository @ Gleeson Library | Geschke Center Master's Projects and Capstones Theses, Dissertations, Capstones and Projects Spring 5-14-2020 A Review of the Methods and Metrics in Research, Implementation, and Management of Integrated Multi-Trophic Aquaculture Cassandra Erickson [email protected] Follow this and additional works at: https://repository.usfca.edu/capstone Part of the Sustainability Commons, and the Water Resource Management Commons Recommended Citation Erickson, Cassandra, "A Review of the Methods and Metrics in Research, Implementation, and Management of Integrated Multi-Trophic Aquaculture" (2020). Master's Projects and Capstones. 1028. https://repository.usfca.edu/capstone/1028 This Project/Capstone is brought to you for free and open access by the Theses, Dissertations, Capstones and Projects at USF Scholarship: a digital repository @ Gleeson Library | Geschke Center. It has been accepted for inclusion in Master's Projects and Capstones by an authorized administrator of USF Scholarship: a digital repository @ Gleeson Library | Geschke Center. For more information, please contact [email protected]. This Master’s Project A Review of Methods and Metrics in Research, Implementation, and Management of Integrated Multi-Trophic Aquaculture By: Cassandra Erickson is submitted in partial fulfillment of the requirements for the degree of Master of Science in Environmental Management at the University of San Francisco Submitted: Received: ..................................................
    [Show full text]
  • And Bathypelagic Fish Interactions with Seamounts and Mid-Ocean Ridges
    Meso- and bathypelagic fish interactions with seamounts and mid-ocean ridges Tracey T. Sutton1, Filipe M. Porteiro2, John K. Horne3 and Cairistiona I. H. Anderson3 1 Harbor Branch Oceanographic Institution, 5600 US Hwy. 1 N, Fort Pierce FL, 34946, USA (Current address: Virginia Institute of Marine Science, P.O.Box 1346, Gloucester Point, Virginia 23062-1346) 2 DOP, University of the Azores, Horta, Faial, the Azores 3 School of Aquatic and Fishery Sciences, University of Washington, Seattle WA, 98195, USA Contact e-mail (Sutton): [email protected]"[email protected] Tracey T. Sutton T. Tracey Abstract The World Ocean's midwaters contain the vast majority of Earth's vertebrates in the form of meso- and bathypelagic ('deep-pelagic,' in the combined sense) fishes. Understanding the ecology and variability of deep-pelagic ecosystems has increased substantially in the past few decades due to advances in sampling/observation technology. Researchers have discovered that the deep sea hosts a complex assemblage of organisms adapted to a “harsh” environment by terrestrial standards (i.e., dark, cold, high pressure). We have learned that despite the lack of physical barriers, the deep-sea realm is not a homogeneous ecosystem, but is spatially and temporally variable on multiple scales. While there is a well-documented reduction of biomass as a function of depth (and thus distance from the sun, ergo primary production) in the open ocean, recent surveys have shown that pelagic fish abundance and biomass can 'peak' deep in the water column in association with abrupt topographic features such as seamounts and mid-ocean ridges. We review the current knowledge on deep-pelagic fish interactions with these features, as well as effects of these interactions on ecosystem functioning.
    [Show full text]
  • The Elements of Marine Life Noah J
    commentary most direct effect of human activity on the whether they do so through phenotypic Nicolas Gruber is in the Environmental oceanic N cycle is the massive application or genotypic changes. Clear latitudinal Physics group, Institute of Biogeochemistry and of fertilizers full of bioavailable N, much trends in the N:P ratio of phytoplankton Pollutant Dynamics, ETH Zürich, 8092 Zürich, of which makes its way to the ocean communities have been found14,15. It Switzerland. Curtis A. Deutsch is at the School of either via rivers or through long-range remains to be seen whether the shifting Oceanography, University of Washington, Seattle, atmospheric transport13. boundaries of major ocean biomes can Washington 98195, USA. Currently, we can only speculate alter the large-scale patterns of plankton e-mail: [email protected] about how these perturbations, and their N:P ratios, and how that would modify the interactions, will alter the marine nitrogen stabilizing feedbacks. References cycle and affect its homeostasis. Given Redfield’s pioneering view of the 1. Redfield, A. C. in James Johnston Memorial Volume that most stabilizing feedbacks operate ocean as a system capable of homeostatic (ed. Daniel, R. J.) 176–192 (Univ. Press of Liverpool, 1934). 2. Redfield, A. C. Am. Sci. 46, 205–221 (1958). on timescales of decades and longer, it is regulation helped pave the way for the 3. Deutsch, C., Sigman, D. M., Thunell, R. C., Meckler, A. N. & likely that we will see widespread temporal broader and now commonplace recognition Haug, G. H. Glob. Biogeochem. Cycles 18, GB4012 (2004). imbalances in the marine nitrogen cycle.
    [Show full text]
  • CO2 Availability Affects Elemental Composition (C:N:P) of the Marine Diatom Skeletonema Costa Tum
    MARINE ECOLOGY PROGRESS SERIES Published August28 Mar EcoI Prog Ser I CO2 availability affects elemental composition (C:N:P) of the marine diatom Skeletonema costa tum Steffen Burkhardt*, Ulf Riebesell Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, D-27570 Bremerhaven, Germany ABSTRACT. The effect of variable CO, concenti-ations on the elemental composition (C N:P) of marine diatoms was investigated in 2 strains of Skeletonema costatum (Grev.)Cleve Five or 6 concentrations of dissolved molecular carbon dioxlde [CO, (aq)],ranging from 0.5 to 39 pm01 I-', were applied in dilute batch cultures. In both strains, elemental ratios were clearly dependent on [CO.(aq)]. With decreasing CO2 concentrations, a decline in C.P and N P and an increase in C:N was observed. The close correla- tion between C:P or N:P and [CO, (aq)]corresponded to a ca 45 to 65?<,decrease in elemental ratios from highest (230 pm01 I-') to lowest (ca 1 pm01 I-') COz concentrations. C:N at low [COz (aq)]was up to 24 % higher than at high [CO, (aq)].To date, the elemental composition of marine phytoplankton has been considered to be independent of CO, availability. If dependency of the C:N:P ratio on [CO2(aq)] proves to be a general phenomenon in marine phytoplankton, changes in the elemental composition may be expected in response to the currently observed increase in partial pressure of atmospher~cCOz. KEY WORDS: Redfield ratio - CO, - Phytoplankton Manne diatoms Cell stoichiometry INTRODUCTION become a limiting factor in the growth of marine plants in the sea' due to the high concentrations of inorganic In the 1930s, Alfred C.
    [Show full text]