1.1-Billion-Year-Old Porphyrins Establish a Marine Ecosystem Dominated by Bacterial Primary Producers

Total Page:16

File Type:pdf, Size:1020Kb

1.1-Billion-Year-Old Porphyrins Establish a Marine Ecosystem Dominated by Bacterial Primary Producers 1.1-billion-year-old porphyrins establish a marine ecosystem dominated by bacterial primary producers N. Guenelia,1, A. M. McKennab, N. Ohkouchic, C. J. Borehamd, J. Beghine, E. J. Javauxe, and J. J. Brocksa,1 aResearch School of Earth Sciences, Australian National University, Canberra, ACT 2601, Australia; bNational High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310-4005; cDepartment of Biogeochemistry, Japan Agency for Marine–Earth Science and Technology, 237-0061 Kanagawa Prefecture, Yokosuka, Natsushimacho, Japan; dGeoscience Australia, Symonston, ACT 2609, Australia; and eDepartment of Geology, Unité de Recherche Geology, University of Liège, 4000 Liege, Belgium Edited by Andrew H. Knoll, Harvard University, Cambridge, MA, and approved June 8, 2018 (received for review March 6, 2018) The average cell size of marine phytoplankton is critical for the the molecular fossils of biological lipids, can provide comple- flow of energy and nutrients from the base of the food web to mentary information about primary producers. For example, higher trophic levels. Thus, the evolutionary succession of primary hydrocarbon fossils of carotenoid pigments extracted from sed- producers through Earth’s history is important for our understand- imentary rocks have been used to detect phototrophic green ing of the radiation of modern protists ∼800 million years ago and (Chlorobiaceae) and purple sulfur bacteria (PSB) (Chromatia- ∼ the emergence of eumetazoan animals 200 million years later. ceae) in 1,640-My-old marine ecosystems (4, 5), while the con- Currently, it is difficult to establish connections between primary centration of eukaryotic steranes, relative to bacterial hopanes, production and the proliferation of large and complex organisms may provide basic information about the ecological relevance of because the mid-Proterozoic (∼1,800–800 million years ago) rock Precambrian algae (6). The relative abundance as well as di- record is nearly devoid of recognizable phytoplankton fossils. We report the discovery of intact porphyrins, the molecular fossils of versity of steranes dramatically increased in the brief interlude chlorophylls, from 1,100-million-year-old marine black shales of between the Sturtian and Marinoan snowball Earth glaciations of – the Taoudeni Basin (Mauritania), 600 million years older than pre- 659 645 Ma, heralding the rise of planktonic algae as important 15 primary producers in the oceans (Fig. 1A). Steranes in the time vious findings. The porphyrin nitrogen isotopes (δ Npor = 5.6– 10.2‰) are heavier than in younger sedimentary sequences, and interval 645 to ∼500 Ma have a strong predominance of stigmastane the isotopic offset between sedimentary bulk nitrogen and por- (a structure with 29 carbon atoms, C29), revealing Chlorophyta, a EARTH, ATMOSPHERIC, AND PLANETARY SCIENCES phyrins (epor = −5.1 to −0.5‰) points to cyanobacteria as domi- division of green algae, as dominant primary producers from the nant primary producers. Based on fossil carotenoids, anoxygenic late Cryogenian to early Paleozoic (Fig. 1) (7, 8). green (Chlorobiacea) and purple sulfur bacteria (Chromatiaceae) Preceding the Cryogenian rise of planktonic algae, the oldest e also contributed to photosynthate. The low por values, in combi- clearly indigenous eukaryotic steranes appear in the geological nation with a lack of diagnostic eukaryotic steranes in the time record ∼900–800 Ma, albeit in low concentrations relative to interval of 1,600–1,000 million years ago, demonstrate that algae bacterial biomarkers (7, 8). These Tonian (1,000–720 Ma) ster- EVOLUTION played an insignificant role in mid-Proterozoic oceans. The paucity anes display a primordial distribution with a nearly 100% pre- of algae and the small cell size of bacterial phytoplankton may dominance of cholestane (C27, red circles in Fig. 1A), which may have curtailed the flow of energy to higher trophic levels, poten- be related to the activity of rhodophytes (9) or heterotrophic tially contributing to a diminished evolutionary pace toward com- eukaryotes (8). plex eukaryotic ecosystems and large and active organisms. chlorophyll | Taoudeni Basin | Mesoproterozoic | compound-specific Significance nitrogen isotopes | primary producers The oceans of Earth’s middle age, 1.8–0.8 billion years ago, were devoid of animal-like life. According to one hypothesis, he succession of primary producers in the oceans shaped the emergence of large, active organisms was restrained by the marine ecology through Earth’s history (1). Primary pro- T limited supply of large food particles such as algae. Through ducers form the base of the food web. Their cell size, elemental the discovery of molecular fossils of the photopigment chlo- stoichiometry, and cell density influence the flow of energy and rophyll in 1.1-billion-year-old marine sedimentary rocks, we nutrients to higher trophic levels (2), presumably setting limits were able to quantify the abundance of different phototrophs. for ecosystem complexity. The composition of phytoplankton The nitrogen isotopic values of the fossil pigments showed communities in Earth’s early oceans, including anoxygenic and that the oceans were dominated by cyanobacteria, while larger oxygenic phototrophic bacteria and eukaryotic algae, may thus planktonic algae were scarce. This supports the hypothesis that have set the pace for the emergence and radiation of different small cells at the base of the food chain limited the flow groups of filter feeders, grazers, and predators, including the of energy to higher trophic levels, potentially retarding the proliferation of modern protists ∼800 Ma and the appearance of emergence of large and complex life. eumetazoan animals some 200 My later (1) (Fig. 1B). Based on the fossil record, chlorophyll c (Chl c) algae, in- Author contributions: N.G. and J.J.B. designed research; N.G., A.M.M., N.O., C.J.B., and cluding dinoflagellates, coccolithophorids, and diatoms, were the J.J.B. performed research; A.M.M., N.O., and C.J.B. contributed new reagents/analytic major energy and carbon source in the oceans of the past ∼250 tools; N.G., A.M.M., N.O., C.J.B., and J.J.B. analyzed data; and N.G., A.M.M., N.O., J.B., My (Fig. 1B). By contrast, Paleozoic (541–251 Ma) and Edia- E.J.J., and J.J.B. wrote the paper. caran (635–541 Ma) oceans were presumably dominated by The authors declare no conflict of interest. primary endosymbiotic algae (Archaeplastida), encompassing This article is a PNAS Direct Submission. the red (Rhodophyta) and green algae (Chlorophyta) (1). Published under the PNAS license. Deeper yet in time, reconstructing the succession of primary 1To whom correspondence may be addressed. Email: [email protected] or jochen. producers becomes challenging. Phytoplankton without a pre- [email protected]. servable cuticle or skeleton are rarely preserved in the body fossil This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10. record, and there are no uncontentious fossils of planktonic 1073/pnas.1803866115/-/DCSupplemental. bacteria or algae in the pre-Ediacaran (3). However, biomarkers, www.pnas.org/cgi/doi/10.1073/pnas.1803866115 PNAS Latest Articles | 1of9 Downloaded by guest on September 24, 2021 A Sterane/hopane ratio B First occurrences (FT-ICR MS), we identify geoporphyrins in 1,100-My-old black 0 2 4 shales. Porphyrins are the molecular fossils of (bacterio)chloro- 0.00 C phylls. Their nitrogen isotopic composition can provide quanti- tative information about dominant phototrophs in past ecosystems (15). Some groups of phototrophs possess a characteristic offset M (epor) between the nitrogen isotopic composition of the whole cell and chlorophylls, independent of the nitrogen source (15), and c Radiation of Chl algae under suitable conditions this isotopic offset is largely unaffected by degradation processes in the water column and bottom sediments P (16). Therefore, the nitrogen isotopic composition of porphyrins in sediments and sedimentary rocks may preserve information about Phanerozoic primary producers present in an ancient environment, largely in- Cambrian Explosion 0.54 Ediacara biota, filter feeders, dependent of physical and chemical conditions such as food source Ed motile animals and diagenesis. 0.63 Radiation of macroalgae Cr Rise of planktonic algae Depositional Environment 0.72 Sturtian glaciation Amoebozoans, rhizarians, Eleven black shales studied for their molecular content (Table 1 predation marks and SI Appendix, Table S1) come from the En Nesoar and Tn first steranes Touirist formations of the 1,100 Ma El Mreïti Group (17) de- Neoprot. posited on an epicratonic platform of the Taoudeni Basin on the cholestane West African Craton (18). The black shales, with a carbon 1.00 no steranes content of up to 32%, accumulated beneath anoxic ferruginous Benthic rhodophytes and occasionally sulfidic waters (19) during maximal flooding of the craton in a quiet subwave base environment possibly pro- tected by offshore stromatolite reefs (18). The black shales contain micrometer-thin laminae of organic matter and pyritized filamentous sheaths that are interpreted as benthic microbial Cyanobacterial porphyrins communities, presumably of heterotrophic and/or chemosyn- Meso- thetic microorganisms thriving beneath anoxic waters (19), and irregularly shaped, discrete or bedding-parallel accumulations of organic particles typical of planktonic debris (SI Appendix, SI Geology and Samples). Oldest eukaryotic fossils 1.60 Results Chromatiaceae Chlorobiacea
Recommended publications
  • Stromatolites
    Stromatolites What is a stromatolite? A stromatolite (literally, ‘layered rock’) is a solid structure created by single-celled microbes called cyanobacteria (blue-green algae). The cyanobacteria form colonies and trap sediment with their sticky surface coatings. The trapped sediment reacts to calcium carbonate in the water to form limestone. These limestone deposits build up very slowly – it can take a stromatolite 100 years to grow 5 cm. A 1 m-high stromatolite might be 2,000 years old! Where are they found? Shark Bay’s stromatolites are found around the shallows of Hamelin Pool , located in the southern part of the eastern bay. Between 4,000 to 6,000 years ago a massive seagrass bank called the Fauré Sill began to block tidal flow into Hamelin Pool, causing the water to become extremely concentrated, or hypersaline. The water in Hamelin Pool is twice as salty as water in the open ocean! Animals that would normally graze on algae, such as chitons and snails, cannot survive in these conditions. Around 3,000 years ago cyanobacteria started flourishing, forming stromatolites much as they did billions of years ago. More than 50 species of cyanobacteria live in Hamelin Pool. What do they look like? Stromatolites look like a cross between a cauliflower and a rock. However, unlike rocks they are actually alive – each stromatolite has a top surface layer teeming with living, active cyanobacteria. At least 3,000 million cyanobacteria can fit in 1 m2! Because cyanobacteria are plants, they photosynthesise their energy from the sun. A by-product of photosynthesis is oxygen, and if you look very carefully you may see the stromatolites gently ‘fizzing’ as tiny bubbles of oxygen are released by the cyanobacteria into the water.
    [Show full text]
  • Carbon Cycling and Calcification in Hypersaline Microbial Mats
    Carbon cycling and calcification in hypersaline microbial mats Dissertation zur Erlangung des Doktorgrades der Naturwissenschaften - Dr. rer. nat.- Dem Fachbereich Biologie/Chemie der Universität Bremen vorgelegt von Rebecca Ludwig Bremen März 2004 Die vorliegende Arbeit wurde in der Zeit von Oktober 2000 bis März 2004 am Max-Planck-Institut für marine Mikrobiologie in Bremen angefertigt. Gutachter Prof. Dr. Bo Barker Jørgensen Prof. Dr. Gunter O. Kirst Prüfer Prof. Dr. Friederike Koenig Dr. Henk M. Jonkers Tag des Promotionskolloqiums: 14. Mai 2004 Table of contents Table of contents Thesis outline v 1 Introduction 1 Prologue 3 Carbon cycle in microbial mats: Organisms and metabolism 8 Gradients and adaptations to diel changes 17 Calcification 20 Principles and applications of microsensors 22 Sampling/study sites 28 2 Structure and function of Chiprana mats 37 Structural and functional analysis of a microbial mat ecosystem from a unique permanent hypersaline inland lake: ‘La Salada de Chiprana’ (NE Spain) 3 Rate limitation in microbial mats 71 Limitation of oxygenic photosynthesis and respiration by phosphate and organic nitrogen in a hypersaline mat: A microsensor study 4 Effect of salinity on benthic photosynthesis 89 Reduced gas diffusivity and solubility limit metabolic rates in benthic phototrophs at high salinities 5 Calcification mechanism in a microbial mat 109 Photosynthesis controlled calcification in a hypersaline microbial mat 6 Stromatolite calcification and bioerosion 127 Balance between microbial calcification and metazoan bioerosion in modern stromatolitic oncolites Discussion 145 Summary 151 Zusammenfassung 153 Appendix 155 Danksagung 155 List of publications 157 iii Outline Thesis outline Five manuscripts are included in this thesis that investigate the carbon cycle in microbial mats with a special emphasis on community carbon flow and mechanisms of microbial calcification.
    [Show full text]
  • Analysis of Stromatolite Reservoir Potential Using Computed Tomography By: Grant Noennig
    Analysis of Stromatolite Reservoir Potential using Computed Tomography By: Grant Noennig A thesis submitted in partial fulfillment of the requirements of the degree of Bachelor of Arts (Geology) At Gustavus Adolphus College 2016 Volumetric Analysis of Stromatolite Reservoir Potential using Computed Tomography By: Grant Noennig Under the supervision of Dr. Julie Bartley ABSTRACT Stromatolites are lithified microbial mats formed when microbes bind and trap carbonate grains or induce precipitation of carbonate material (Ahr et al., 2011). If sufficient porosity occurs within these microbialites, they have potential to contain and transmit fluids, such as petroleum. Carbonate rock accounts for more than half of the world's oil reservoirs and 40% of the world's natural gas reservoirs, but due to the complexity of fractures and matrix composing these beds, their reservoir potentials are difficult to estimate (EIA, 2013). Stromatolites from the Laney Member of the hydrocarbon-rich Green River Formation in the central United States offer an opportunity to study reservoir potential in a well-exposed succession. Most research on carbonate reservoir potential is sedimentary, stratigraphic, or petrophysical, but more complex reservoirs like stromatolites require specific techniques to determine their potential (Rezende et al., 2013). In order to determine the porosity, permeability, and pore-connectivity of this facies, samples from this location were cut into rectangular blocks and scanned using x-ray computed tomography (XRCT) at the University of Minnesota. XRCT analysis allows for the quantification of porosity and permeability values to evaluate the reservoir potential at a small scale, in three dimensions. Preliminary results indicate that Green River stromatolites are highly variable in their porosity characteristics, but some have sufficient porosity and permeability to be effective reservoir rock.
    [Show full text]
  • Grain Trapping by Microbial Mats: Implications for Stromatolites
    Grain trapping by microbial mats: Implications for stromatolites Frank Corsetti Department of Earth Sciences University of Southern California Rocks = Time Rocks = Environment Rocks = History of Life Stromatolite sharkbay.org Stromatolite Textbook Definition • laminated • organo-sedimentary structure • built by microbes (CCALA) Cyanobacteria Cyanobacteria microbial mat (“pond scum”) Stromatolite Textbook Definition Trapping and Binding 100 microns Stromatolite courtesy of Y. Ibarra Textbook Definition Mineral Precipitation Stromatolite Significance • Macroscopic from Microscopic Stromatolite Significance putative • Oldest fossils in the world ^ Warrawoona Fm Western Australia 3.5 Ga 2 cm Ancient Life: Greatest Hits Cambrian explosion Hadean Archean Proterozoic Phan. 4.0 3.0 2.0 1.0 0 billions of years LETTERS NATURE | Vol 457 | 5 February 2009 Masirah Bay Fm. soft-body parts, as detected in Doushantuo phosphorites19,22, is rare in ααα ααα αββ the geological record. Siliceous sponge spicules are metastable and S R C (17%) they can be difficult to isolate and identify unambiguously in clastic 26 sediments. Moreover, several orders of Demospongiae completely *** * 358 → 217 lack mineral skeletons. On the other hand, the studies of the lipid ααα ααα compositions of Porifera show a remarkable diversity of distinctive αββ C27 (21%) 13,27,28 R structures with abundance patterns aligned to phylogeny S 372 → 217 The demosponge biomarker record for the Huqf Supergroup supports the hypothesis that Metazoa first achieved ecological 1 αββ ααα ααα prominence in shallow marine waters of the Cryogenian . It has been C28 (16%) 386 → 217 proposed that Neoproterozoic sponges and rangeomorphs feeding S R on reactive dissolved or particulate marine organic matter29 may have progressively oxygenated their benthic environments as they moved ααα ααα αββ 24 C29 (39%) from shallow water into deeper waters .
    [Show full text]
  • Stromatolites
    Stromatolites edited by David L. Alles Western Washington University e-mail: [email protected] Last Updated 2012-3-28 Note: In PDF format most of the images in this web paper can be enlarged for greater detail. 1 Bahamian Stromatolites by Chet Raymo "EXUMA, Bahamas—I felt a bit like a field cryptozoologist recently as I snorkeled in the shallow waters of a tidal channel near Lee Stocking Island in the Exuma Cays of the Bahamas. Below were dozens of massive ovoid humps (shown above), many three feet or more high, like giant dinosaur eggs partly buried in the seafloor sand. These strange objects were clearly of biological origin, but unlike anything I had seen before. In water made milky by tide-stirred sand, they beckoned as if from some prehistoric dream. These are the famous Bahamian giant stromatolites, and their story is as curious as any wide- eyed tale of the Loch Ness monster." "Stromatolites are stony structures built up by living organisms, in this case by algae and cyanobacteria (photosynthesizing bacteria). The microbes live in gooey mats on the top surface of the structures. The mats trap fine sediments carried across them by tidal currents. As the mats are made opaque by sediments, the microbes move upwards seeking sunlight. Layer after layer of sediments are cemented into growing columns or domes. 2 Large stromatolites were common in the seas of the early Earth, but they are rare today. They are found only at a few sites in the Bahamas and at Shark Bay in western Australia. For more than 3 billion years after the formation of the Earth, all life on the planet was microscopic, ancestral to the algae and cyanobacteria of the Bahamian stromatolites.
    [Show full text]
  • Shark Bay Microbialites: a Walk Through Technological Time
    Shark Bay microbialites: a walk through technological time Brendan Burns and Pieter Visscher DEC symposium on research and conservation October 2012 Outline 1. Shark Bay microbialites 2. Initial diversity studies 3. Tagged pyrosequencing 4. Functional metagenomic sequencing 5. Microelectrode profiling 6. Conservation and sustainability 7. Where to from here…. Applications of genomic, proteomic, microbiological, and analytical chemical tools in the study of functional complexity Outline 1. Shark Bay microbialites 2. Initial diversity studies 3. Tagged pyrosequencing 4. Functional metagenomic sequencing 5. Microelectrode profiling 6. Conservation and sustainability 7. Where to from here…. Overall strategic research goals Comprehensively study the functional complexity of modern microbialites, as a model system for understanding the intricate interactions between microorganisms and their physical environment and their potential roles in the wider biosphere Hypothesis Microbial metabolisms (and interactions) determine stromatolite function, morphology, and persistence Hamelin Pool (Shark Bay) ,Western Australia Shark Bay microbialites • One of the best examples on earth of living marine microbialites • Surrounding seawater at least twice as saline as normal seawater (fluctuates); high UV, desiccation • Higher salinity in early oceans • Key to understanding the past is to study the present Outline 1. Shark Bay microbialites 2. Initial diversity studies 3. Tagged pyrosequencing 4. Functional metagenomic sequencing 5. Microelectrode profiling
    [Show full text]
  • The Geological Succession of Primary Producers in the Oceans
    CHAPTER 8 The Geological Succession of Primary Producers in the Oceans ANDREW H. KNOLL, ROGER E. SUMMONS, JACOB R. WALDBAUER, AND JOHN E. ZUMBERGE I. Records of Primary Producers in Ancient Oceans A. Microfossils B. Molecular Biomarkers II. The Rise of Modern Phytoplankton A. Fossils and Phylogeny B. Biomarkers and the Rise of Modern Phytoplankton C. Summary of the Rise of Modern Phytoplankton III. Paleozoic Primary Production A. Microfossils B. Paleozoic Molecular Biomarkers C. Paleozoic Summary IV. Proterozoic Primary Production A. Prokaryotic Fossils B. Eukaryotic Fossils C. Proterozoic Molecular Biomarkers D. Summary of the Proterozoic Record V. Archean Oceans VI. Conclusions A. Directions for Continuing Research References In the modern oceans, diatoms, dinoflagel- geobiological prominence only in the Mesozoic lates, and coccolithophorids play prominent Era also requires that other primary producers roles in primary production (Falkowski et al. fueled marine ecosystems for most of Earth 2004). The biological observation that these history. The question, then, is What did pri- groups acquired photosynthesis via endo- mary production in the oceans look like before symbiosis requires that they were preceded in the rise of modern phytoplankton groups? time by other photoautotrophs. The geologi- In this chapter, we explore two records cal observation that the three groups rose to of past primary producers: morphological 133 CCh08-P370518.inddh08-P370518.indd 113333 55/2/2007/2/2007 11:16:46:16:46 PPMM 134 8. THE GEOLOGICAL SUCCESSION OF PRIMARY PRODUCERS IN THE OCEANS fossils and molecular biomarkers. Because without well developed frustules might these two windows on ancient biology are well leave no morphologic record at all in framed by such different patterns of pres- sediments.
    [Show full text]
  • Factors Affecting Phytoplankton Biodiversity and Toxin Production Tracey Magrann Loma Linda University
    Loma Linda University TheScholarsRepository@LLU: Digital Archive of Research, Scholarship & Creative Works Loma Linda University Electronic Theses, Dissertations & Projects 6-1-2011 Factors Affecting Phytoplankton Biodiversity and Toxin Production Tracey Magrann Loma Linda University Follow this and additional works at: http://scholarsrepository.llu.edu/etd Part of the Biology Commons Recommended Citation Magrann, Tracey, "Factors Affecting Phytoplankton Biodiversity and Toxin Production" (2011). Loma Linda University Electronic Theses, Dissertations & Projects. 45. http://scholarsrepository.llu.edu/etd/45 This Dissertation is brought to you for free and open access by TheScholarsRepository@LLU: Digital Archive of Research, Scholarship & Creative Works. It has been accepted for inclusion in Loma Linda University Electronic Theses, Dissertations & Projects by an authorized administrator of TheScholarsRepository@LLU: Digital Archive of Research, Scholarship & Creative Works. For more information, please contact [email protected]. LOMA LINDA UNIVERSITY School of Science and Technology in conjunction with the Faculty of Graduate Studies ____________________ Factors Affecting Phytoplankton Biodiversity and Toxin Production by Tracey Magrann ____________________ A Dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Biology ____________________ June 2011 © 2011 Tracey Magrann All Rights Reserved Each person whose signature appears below certifies that this dissertation in his opinion is adequate, in scope and quality, as a dissertation for the degree Doctor of Philosophy. , Chairperson Stephen G. Dunbar, Associate Professor of Biology Danilo S. Boskovic, Assistant Professor of Biochemistry, School of Medicine H. Paul Buchheim, Professor of Geology William K. Hayes, Professor of Biology Kevin E. Nick, Associate Professor of Geology iii ACKNOWLEDGEMENTS I would like to express my deepest gratitude to Dr.
    [Show full text]
  • Microbialites, Stromatolites, and Thrombolites 635
    MICROBIALITES, STROMATOLITES, AND THROMBOLITES 635 Simkiss, K., and Wilbur, K., 1989. Biomineralization. Cell Biology Mineralogy and Geochemistry. Washington: Mineralogical and Mineral Deposition. San Diego: Academic. Society of America, Vol. 54, pp. 1–31. Stal, L. J., 2000. Microbial mats and stromatolites. In Whitton, Wright, V. P., Platt, N. H., and Wimbledon, W. A., 1988. Biogenic B. A., and Potts, M. (eds.), The Ecology of Cyanobacteria. Their laminar calcrete: evidence of calcified root-mat horizons in Diversitty in Time and Space. Dordrecht: Kluwer. paleosols. Sedimentology, 35, 603–620. Stal, L. J., 2003. Microphytobenthos, their extracellular polymeric Yechieli, Y., and Wood, W. W., 2002. Hydrogeologic processes in substances, and the morphogenesis of intertidal sediments. saline systems: playas, sabkhas, and saline lakes. Earth-Science Geomicrobioly Journal, 20, 463–478. Reviews, 58, 343–365. Stolz, J. F., 2000. Structure of microbial mats and biofilms. In Zabielski, V. P., 1991. The depositional history of Storr’s Lake San Riding, R. E., Awramik, S. M. (eds.), Microbial Sediments. Salvador, Bahamas. Unpublished PhD thesis, University of New York: Springer, pp. 1–9. North Carolina. Stumm, W., and Morgan, J. J., 1996. Aquatic Chemistry. New York: Zeebe, R. E., and Wolf-Gladrow, D. (eds.), 2001. CO2 in Seawater: Wiley, 1022 pp. Equilibrium, Kinetics and Isotopes.Amsterdam:Elsevier,346pp. Thode-Andersen, S., and Jorgensen, B. B., 1989. Sulfate reduction 35 and the formation of S-labeled FeS, FeS2, and S(0) (elemental sulfur) in coastal marine sediments. Limnology and Oceanogra- Cross-references phy, 34, 793–806. Biofilms Thompson, J. B., and Ferris, F. G., 1990. Cyanobacterial precipita- Extracellular Polymeric Substances (EPS) tion of gypsum, calcite, and magnesite from natural alkaline lake Microbial Biomineralization water.
    [Show full text]
  • What Is a Coral Reef?
    What is a coral reef? Paralyzing its prey Coral reefs are colonies of small animals, known as polyps, tentacles with nematocysts Corals feed using their tentacles to capture their prey, which includes tiny barbs cross section (stinging cells) which release calcium carbonate to form a of a coral polyp animals called zooplankton and small fish. The tentacles contain small stinging thread hard skeleton on which they live. cells called nematocysts. Inside the stinging cell is a thread that is coiled under operculum Coral reefs are found in pressure and wrapped around a stinging barb. When potential prey touches the shallow, tropical waters tentacles, the flap, or operculum, on top of the cell flies open, the thread rapidly around the world. uncoils, and the barb is ejected. The barbs are designed to penetrate the victim’s Living coral reefs skin and inject a venom. When the prey is subdued, the tentacles move it into provide homes for the polyp’s mouth and the nematocysts recoil into their capsules. capsule large numbers of zooxanthellae mouth marine animals. living tissue nematocyst linking polyps coral nematocyst In fact, coral reefs World’s largest living structure polyp There are four types of reefs: barrier, stromatolite, patch, and fringe reefs. make up only 1 percent of the Barrier reefs are the largest living structures in the world and are formed by coral running roughly parallel to the shore, which is ocean’s habitat but separated from it by a wide, deep lagoon. include over 25 percent of its species. Stromatolites (which means “layered rock”) are formations created by microscopic, blue-green algae.
    [Show full text]
  • Stromatolites: What They Are and What They Mean to Us
    NATURALIST CORNER Stromatolites: What Th ey Are and What Th ey Mean to Us Text and Photographs by Wayne P. Armstrong elevating the level of free oxygen in the earth’s atmosphere. As one gazes at the spectacular limestone formations in Glacier National Park and the Canadian Rockies, you are awe-struck with the enormous role these ancient cyanobacteria played as they removed carbon dioxide from primeval seas and precipitated it as massive calcium carbonate rocks. Releasing oxygen gas as a metabolic by-product, they must have been a major factor in producing the oxygen-rich atmosphere that allowed the development of other aerobic life forms on earth.In 1990, Dr. Paul Buchheim of the Department of Earth and Biological Sciences at Loma Linda University One billion-year-old stromatolites embedded reported living stromatolites in Carrizo in limestone along Going-To-Th e Sun Road Gorge and San Felipe Creek in Sentenac in Glacier National Park, Montana. Th e Canyon, both within Anza-Borrego Desert concentric rings represent calcareous layers State Park. Previous to this discovery, where ancient colonies of cyanobacteria once modern-day stromatolites were unknown thrived in shallow seas. An ephemeral stream in Grapevine Canyon north of Mexico. Th ese shallow, ephemeral Stromatolites are layered (laminate), of Anza-Borrego Desert State Park. Th e (intermittent) streams have boulders and calcareous structures formed by colonies of submersed boulders and cobbles are encrusted cobbles coated with knobby, calcareous cyanobacteria (formerly called blue-green with living colonies of stromatolite-forming layers and living colonies of mucilaginous, algae). Along road cuts in Glacier National cyanobacteria.
    [Show full text]
  • Insights Into Foraminiferal Influences on Microfabrics of Microbialites At
    Insights into foraminiferal influences on microfabrics of microbialites at Highborne Cay, Bahamas Joan M. Bernharda,1, Virginia P. Edgcomba, Pieter T. Visscherb, Anna McIntyre-Wressniga, Roger E. Summonsc, Mary L. Bouxseind,e, Leeann Louisd, and Marleen Jeglinskia aGeology and Geophysics Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543; bDepartment of Marine Sciences, University of Connecticut, Groton, CT 06340; cEarth, Atmospheric and Planetary Department, Massachusetts Institute of Technology, Cambridge, MA 02139; dCenter for Advanced Orthopedic Studies, Beth Israel Deaconess Medical Center, Boston, MA 02215; and eDepartment of Orthopedic Surgery, Harvard Medical School, Boston, MA 02215 Edited by John M. Hayes, Woods Hole Oceanographic Institution, Woods Hole, MA, and approved May 2, 2013 (received for review December 12, 2012) Microbialites, which are organosedimentary structures formed by Foraminiferal eukaryotes are a major component of most microbial communities through binding and trapping and/or in present-day marine benthic habitats. Benthic foraminifera can be situ precipitation, have a wide array of distinctive morphologies important primary carbonate producers (10), hosts of photoau- and long geologic record. The origin of morphological variability totrophic endobionts (11), and significant players in food-web is hotly debated; elucidating the cause or causes of microfabric dynamics (12). Although the most familiar foraminifera today differences could provide insights into ecosystem functioning and have calcareous tests (shells), agglutinated and organic (thecate biogeochemistry during much of Earth’s history. Although rare or allogromid) foraminifera also exist (13). Agglutinated fora- today, morphologically distinct, co-occurring extant microbialites miniferal species create tests by assembling inorganic grains us- provide the opportunity to examine and compare microbial com- ing a bioadhesive, and thecate foraminifera have an organic test.
    [Show full text]