DOCSLIB.ORG

Resource Newsletter: Planet Ocean

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Resource Newsletter: Planet Ocean National Park Service Point Reyes National Seashore U.S. Department of the Interior PLANET OCEAN How inappropriate to call this planet Earth when it is quite clearly Ocean. Arthur C. Clarke NASA 2011 Visible in the foreground is the island of Andros in the Bahamas, surrounded by azure-colored shallow waters, looking out to the continental shelf and the deeper blue of the Atlantic Ocean. Why We Live Here Imagine you are flying in gigantic cosmic explosion called the “Big may have prevented them from becoming Bang.” The origin of earth’s water is not liquid water worlds. Venus is closer to the Sun, from a distant galaxy to our solar system. You entirely known but several theories exist and Mars farther from the Sun than Earth. come through the icy debris of the Kuiper to explain it. As our planet coalesced out Venutian water may have boiled off because its Belt, past Neptune and Uranus, on by the gas of this dust cloud, it grew very hot, and surface temperature is so hot. Martian water giants, Saturn and Jupiter. Then, after making volcanic eruptions happened frequently. The may once have flowed, but now is thought to it through a belt of asteroids, you hover over eruptions brought water to the surface as well be locked up as ice, mostly below the planet’s little, red, rocky Mars for a look. Next you see as magma. The earth’s gravity increased and rocky, red surface. a lovely, bright blue orb partially shrouded in more water from the inner solar system was white clouds. It looks like no other place in captured by our growing planet. In addition, So we live on this blue planet—because life, the neighborhood. What gives it its distinctive comets—largely made of ice—collided with the as we know it, requires liquid water to form. look? young Earth. These are proposed sources are By three billion years ago, the ocean basins liquid water proposed for Earth's water. were filled with water to about their current depths, and the first living things probably Billions of years ago according to most Our nearest planetary neighbors, Venus and formed in warm, shallow, ocean water. Inside, scientists, Earth materialized out of collisions Mars had similar formative experiences, but you can learn more about our oceans and our of dust, gas, and water that resulted from a the position of their orbits around our Sun connections to them. Inside Page Why The Ocean Matters 2 Please use caution when Visit the Point Reyes In The Zone 2 recreating near or in Lighthouse, walk the Land And Water In Motion 3 the Pacific Ocean. The stairs and get a stamp to The Bottom of the Food Chain 4 Point Reyes beaches are prove you did it! Journeys 5 subject to rip currents Humans And Oceans 6 and rogue waves that Page 8 has activities for Food For Thought 7 pose significant dangers. kids and you can collect Out At The Point 7 some animal stamps! Kid’s Activities 8 Page 1 Why The Ocean Matters 1. The Earth has one ocean with many basins. O2 2. The ocean covers about 70% of the Earth’s surface, 1 and contains about 97% of the Earth’s water. 3 2 CO2 4 3. Half of Earth’s oxygen is produced in the sunlit ocean layers, and half of the carbon dioxide in the atmosphere is absorbed by the ocean. It’s the blue heart of the planet — and we should 4. Most rain, the source of much of our 5 drinking water, comes from the ocean. take care of our heart. It’s 6 what makes life possible 5. The ocean is a major influence on weather and climate. for us. 6. The ocean and ocean life shape the —Sylvia Earle shoreline features of the Earth. 8 7. Life in the ocean is diverse. The smallest known virus and the largest animal live in 7 the ocean. 8. Many geologic and geochemical cycles begin in ? the ocean. 9 9. Most of our knowledge of the ocean comes from shallower waters. Less than 5% has been explored. ? 10 10. Humans and all living things are inextricably connected to the ocean. In The Zone The Atmosphere—(an ocean of water, in the air): Intertidal Zone (In Epipelagic Zone) • Tufted Puffins can dive up to 196 feet (60 m) • Pigeon Guillemots can dive up to 212 feet (65m) Splash Zone organisms depend on sea spray for moisture, adapted Epipelagic Zone—To 650 feet (200 m) below the to long periods of surface—The sunlit upper layer of the ocean exposure • Moon Jellyfish • Barnacles • Many Sharks • Ribbed Limpets • Dolphins High Tide Zone Mesopelagic Zone—To 3300 feet (1000 m) organisms covered at most high tides below the surface—The twilight zone • Turban Snails • Swordfish • Chiton • Wolf Eel Mid Tide Zone • Ochre Sea Star • Green Anemone Bathypelagic Zone—To 13,000 feet Low Tide Zone (4,000 m) below the surface— most protection from The midnight zone (no sunlight) desiccation; inhabited • Anglerfish by the most number of species • Many Octopus • Dungeness Crab • Sea Hare Abyssopelagic Zone—To a known depth of 36,067ft or 6.831 mi (10, 993 m)—The abyss * The Abyssopelagic zone continues to yield its • Microbes secrets. In December 2014 a snailfish was found •* 5 miles (8 km) deep in the Mariana Trench! Page 2 Land and Water In Motion Land and Water Oceans and Climate The California Current Continental crust 15–45 miles (25-75 km) thick Earth rotates eastward, contributing to the The California Current flows south from Oceanic crust 4.5–6.3 miles (7-10 km) thick circular movement of air across the oceans. along British Columbia's shoreline as part of Relative to this rotation, the air is deflected to the North Pacific gyre. This river of water Our planet’s surface is divided into thin, the right in the Northern Hemisphere, and to flows along the coast from north to south and stiff plates that move around on molten the left in the Southern Hemisphere, causing before ending off southern Baja California magma. If all of the plates were made of the winds to develop. These global winds drag on Peninsula. Additionally during the spring same material, and the surface of the earth the oceans’ surface causing surface currents, months, prevailing northwesterly winds push was smooth, the oceans would cover the and the currents form ocean-circling spirals the warmer surface waters away from shore, earth to an average depth of 6500 ft. (2000 called gyres. which allows colder water from the sunless m)! But there are two plate types: denser, depths to rise to the surface. This process, thinner, balsalt oceanic rocks and lighter, The oceans strongly impact the world’s known as upwelling, is responsible for the very thicker, granitic, continental rocks. If you climate. Energy from the sun is absorbed and nutrient-rich waters off the California Coast. put a wooden block and a styrofoam block then circulated around the world in warm in a swimming pool, both would float, but surface currents. Since the cold waters are rich with nutrients the denser wood would float lower than the and more saturated with oxygen, they support styrofoam. Similarly, the dense basalt sinks a rich community of plankton (more on page deeper into the mantle, creating basins where Ocean Motion 4) , the basis of the marine food chain. In the water collects to form the great oceans of Water in the ocean is constantly moving. A general, the strongest upwelling happens the world. deep, global conveyor current underlies the between Point Conception and Cape surface currents. These are the thermohaline Mendocino. The largest seabird rookery south Water evaporates from the ocean and currents. These currents are density driven, of Alaska, the Farallon Islands, is situated in falls over land as rain. As the ocean water resulting from differences in temperature the middle of this area. evaporates, the minerals—mostly salt— and salinity. Dense, cold, salty water sinks remain behind in the sea. These ocean while warm, less salty water rises to the minerals originally came from rain water surface. The “start” of the ocean conveyor flowing over continental rocks, dissolving belt is in the northern polar regions. Cold minerals from those rocks, and flowing out arctic water sinks to the ocean bottom, and to sea. Deep in ocean trenches, there are is carried south, eventually flowing all the hydrothermal vents that also release minerals way to Antarctica! Over time this water Cape into the oceans. This is why ocean water is on warms up again, rises to the surface and Mendocino average seventy times more salty than fresh flows back north, where warm water currents g in water. ll Point carry water from the equator to the north, e w Reyes Because of the extra minerals, saltwater and heat is lost again to the atmosphere in p U Farallon the northern latitudes. This motion forms a t is denser than fresh water. When you see s Islands e globe-encircling oceanic conveyer belt. One t large rivers flowing out into the ocean, the a drop of water spends about 1000 years making e fresh water floats on top which causes color r G a round trip of over 25,000 miles! variations of the nearshore waters. f Point o Conception e n o Z Oyashio Ocean Waves Bering Alaska A wave is a disturbance that carries energy from one place to another. What we are North Pacific witnessing when we look at waves is the energy moving through the water, not the water moving horizontally any significant Kuroshio distance.
Load more

Recommended publications
  • 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]
  • 8.4 the Significance of Ocean Deoxygenation for Continental Margin Mesopelagic Communities J
    8.4 The significance of ocean deoxygenation for continental margin mesopelagic communities J. Anthony Koslow 8.4 The significance of ocean deoxygenation for continental margin mesopelagic communities J. Anthony Koslow Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia and Scripps Institution of Oceanography, University of California, SD, La Jolla, CA 92093 USA. Email: [email protected] Summary • Global climate models predict global warming will lead to declines in midwater oxygen concentrations, with greatest impact in regions of oxygen minimum zones (OMZ) along continental margins. Time series from these regions indicate that there have been significant changes in oxygen concentration, with evidence of both decadal variability and a secular declining trend in recent decades. The areal extent and volume of hypoxic and suboxic waters have increased substantially in recent decades with significant shoaling of hypoxic boundary layers along continental margins. • The mesopelagic communities in OMZ regions are unique, with the fauna noted for their adaptations to hypoxic and suboxic environments. However, mesopelagic faunas differ considerably, such that deoxygenation and warming could lead to the increased dominance of subtropical and tropical faunas most highly adapted to OMZ conditions. • Denitrifying bacteria within the suboxic zones of the ocean’s OMZs account for about a third of the ocean’s loss of fixed nitrogen. Denitrification in the eastern tropical Pacific has varied by about a factor of 4 over the past 50 years, about half due to variation in the volume of suboxic waters in the Pacific. Continued long- term deoxygenation could lead to decreased nutrient content and hence decreased ocean productivity and decreased ocean uptake of carbon dioxide (CO2).
    [Show full text]
  • Coastal and Marine Ecological Classification Standard (2012)
    FGDC-STD-018-2012 Coastal and Marine Ecological Classification Standard Marine and Coastal Spatial Data Subcommittee Federal Geographic Data Committee June, 2012 Federal Geographic Data Committee FGDC-STD-018-2012 Coastal and Marine Ecological Classification Standard, June 2012 ______________________________________________________________________________________ CONTENTS PAGE 1. Introduction ..................................................................................................................... 1 1.1 Objectives ................................................................................................................ 1 1.2 Need ......................................................................................................................... 2 1.3 Scope ........................................................................................................................ 2 1.4 Application ............................................................................................................... 3 1.5 Relationship to Previous FGDC Standards .............................................................. 4 1.6 Development Procedures ......................................................................................... 5 1.7 Guiding Principles ................................................................................................... 7 1.7.1 Build a Scientifically Sound Ecological Classification .................................... 7 1.7.2 Meet the Needs of a Wide Range of Users ......................................................
    [Show full text]
  • Respiration in the Mesopelagic and Bathypelagic Zones of the Oceans
    CHAPTER 10 Respiration in the mesopelagic and bathypelagic zones of the oceans Javier Arístegui1, Susana Agustí2, Jack J. Middelburg3, and Carlos M. Duarte2 1 Facultad de Ciencias del Mar, Universidad de las Palmas de Gran Canaria, Spain 2 IMEDEA (CSIC–UIB), Spain 3 Netherlands Institute of Ecology, The Netherlands Outline In this chapter the mechanisms of transport and remineralization of organic matter in the dark water-column and sediments of the oceans are reviewed. We compare the different approaches to estimate respiration rates, and discuss the discrepancies obtained by the different methodologies. Finally, a respiratory carbon budget is produced for the dark ocean, which includes vertical and lateral fluxes of organic matter. In spite of the uncertainties inherent in the different approaches to estimate carbon fluxes and oxygen consumption in the dark ocean, estimates vary only by a factor of 1.5. Overall, direct measurements of respiration, as well as − indirect approaches, converge to suggest a total dark ocean respiration of 1.5–1.7 Pmol C a 1. Carbon mass − balances in the dark ocean suggest that the dark ocean receives 1.5–1.6 Pmol C a 1, similar to the estimated respiration, of which >70% is in the form of sinking particles. Almost all the organic matter (∼92%) is remineralized in the water column, the burial in sediments accounts for <1%. Mesopelagic (150–1000 m) − − respiration accounts for ∼70% of dark ocean respiration, with average integrated rates of 3–4 mol C m 2 a 1, − − 6–8 times greater than in the bathypelagic zone (∼0.5 mol C m 2 a 1).
    [Show full text]
  • MARINE ENVIRONMENTS Teaching Module for Grades 6-12
    MARINE ENVIRONMENTS Teaching Module for Grades 6-12 Dear Educator, We are pleased to present you with the first in a series of teaching and learning modules developed by the DEEPEND (Deep-Pelagic Nekton Dynamics) consortium and their consultants. DEEPEND is a research network focusing primarily on the pelagic zone of the Gulf of Mexico, therefore the majority of the lessons will be based around this topic. Whenever possible, the lessons will focus specifically on events of the Gulf of Mexico or work from the DEEPEND scientists. All modules in this series aim to engage students in grades 6 through 12 in STEM disciplines, while promoting student learning of the marine environment. We hope these lessons enable teachers to address student misconceptions and apprehensions regarding the unique organisms and properties of marine ecosystems. We intend for these modules to be a guide for teaching. Teachers are welcome to use the lessons in any order they wish, use just portions of lessons, and may modify the lessons as they wish. Furthermore, educators may share these lessons with other school districts and teachers; however, please do not receive monetary gain for lessons in any of the modules. Moreover, please provide credit to photographers and authors whenever possible. This first module focuses on the marine environment in general including biological, chemical, and physical properties of the water column. We have provided a variety of activities and extensions within this module such that lessons can easily be adapted for various grade and proficiency levels. Given that education reform strives to incorporate authentic science experiences, many of these lessons encourage exploration and experimentation to encourage students to think and act like a scientist.
    [Show full text]
  • Ocean Depths: the Mesopelagic and Implications for Global Warming
    Current Biology Dispatches Ocean Depths: The Mesopelagic and Implications for Global Warming Mark J. Costello1,* and Sean Breyer2 1Institute of Marine Science, University of Auckland, Auckland, 1142, New Zealand 2ESRI, Redlands, CA 92373, USA *Correspondence: [email protected] http://dx.doi.org/10.1016/j.cub.2016.11.042 The mesopelagic or ‘twilight zone’ of the oceans occurs too deep for photosynthesis, but is a major part of the world’s carbon cycle. Depth boundaries for the mesopelagic have now been shown on a global scale using the distribution of pelagic animals detected by compiling echo-soundings from ships around the world, and been used to predict the effect of global warming on regional fish production. Depth Zonation Analyses were at 5 m depth intervals to However, it remains to be clearly shown The classical concepts for depth zonation 1,000 m deep, and a spatial resolution of whether the abyssal zone is ecologically [1] in the ocean begin at the seashore 300 km2. distinct from the bathyal. (Table 1). Distinct communities are visible The environment changes less as we The data shown in Figure 1 are global on the rocky seashore, and reflect the go deeper (Figure 1), so we expect the averages, and local exceptions will occur, adaptations of their animals and plants vertical extent of ecological zones to particularly in more enclosed waters such to exposure to air and wave action, increase with depth. While the rocky as the Mediterranean and Black Seas [6]. as well as the effects of grazing and seashore may have distinct habitats only The seabed-resident fauna (benthos) will predation [2].
    [Show full text]
  • Trophic Diversity of Plankton in the Epipelagic and Mesopelagic Layers of the Tropical and Equatorial Atlantic Determined with Stable Isotopes
    diversity Article Trophic Diversity of Plankton in the Epipelagic and Mesopelagic Layers of the Tropical and Equatorial Atlantic Determined with Stable Isotopes Antonio Bode 1,* ID and Santiago Hernández-León 2 1 Instituto Español de Oceanografía, Centro Oceanográfico de A Coruña, Apdo 130, 15080 A Coruña, Spain 2 Instituto de Oceanografía y Cambio Global (IOCAG), Universidad de las Palmas de Gran Canaria, Campus de Taliarte, Telde, Gran Canaria, 35214 Islas Canarias, Spain; [email protected] * Correspondence: [email protected]; Tel.: +34-981205362 Received: 30 April 2018; Accepted: 12 June 2018; Published: 13 June 2018 Abstract: Plankton living in the deep ocean either migrate to the surface to feed or feed in situ on other organisms and detritus. Planktonic communities in the upper 800 m of the tropical and equatorial Atlantic were studied using the natural abundance of stable carbon and nitrogen isotopes to identify their food sources and trophic diversity. Seston and zooplankton (>200 µm) samples were collected with Niskin bottles and MOCNESS nets, respectively, in the epipelagic (0–200 m), upper mesopelagic (200–500 m), and lower mesopelagic layers (500–800 m) at 11 stations. Food sources for plankton in the productive zone influenced by the NW African upwelling and the Canary Current were different from those in the oligotrophic tropical and equatorial zones. In the latter, zooplankton collected during the night in the mesopelagic layers was enriched in heavy nitrogen isotopes relative to day samples, supporting the active migration of organisms from deep layers. Isotopic niches showed also zonal differences in size (largest in the north), mean trophic diversity (largest in the tropical zone), food sources, and the number of trophic levels (largest in the equatorial zone).
    [Show full text]
  • 1. Describe the Principal Oceans of Earth, Including the Following: A
    Chapter 1: Upon completion of this chapter, the student should be able to: 1. Describe the principal oceans of Earth, including the following: A. location B. relative size C. land forms that border the ocean 2. Name the deepest ocean trench and describe its exploration by humans. 3. Discuss early ocean exploration and include the contributions of: A. early Pacific islanders (4000 BC– 900 AD) B. the Kon Tiki voyage C. Phoenicians D. Greeks E. Romans 4. Describe the contributions to oceanic exploration during the Middle Ages and the Ming Dynasty, including the: A. Arabs B. Vikings Ming Dynasty (1405–1433) 5. Elaborate on the contributions to oceanic exploration made by European explorers during the Renaissance (Age of Discovery), including: A. Prince Henry the Navigator B. Vasco da Gama C. Christopher Columbus D. John Cabot E. Vasco Nùñez de Balboa F. Ferdinand Magellan G. Juan Sebastian del Caño 6. Discuss the contributions of James Cook to early ocean science. 7. List and describe the systematic steps of the scientific method. 8. Distinguish between a hypothesis and a theory. 9. Describe the formation of the solar system as outlined by the nebular hypothesis. 10. Compare and contrast Protoearth and modern Earth. 11. Describe density stratification in Earth and the resultant chemical structure, including the: A. crust B. mantle C. core 12. Describe the physical structure of Earth, including the: A. inner core B. outer core C. mesosphere D. asthenosphere E. lithosphere 13. Distinguish between continental crust and oceanic crust, including location, chemical, and physical properties of the crust. 14. Differentiate between isostatic adjustment and isostatic rebound.
    [Show full text]
  • How Did the Deepwater Horizon Oil Spill Impact Deep-Sea Ecosystems? Charles R
    Nova Southeastern University NSUWorks Marine & Environmental Sciences Faculty Articles Department of Marine and Environmental Sciences 9-1-2016 How Did the Deepwater Horizon Oil Spill Impact Deep-Sea Ecosystems? Charles R. Fisher Pennsylvania State University - Main Campus Paul A. Montagna Texas A & M University - Corpus Christi Tracey Sutton Nova Southeastern University, [email protected] Find out more information about Nova Southeastern University and the Halmos College of Natural Sciences and Oceanography. Follow this and additional works at: https://nsuworks.nova.edu/occ_facarticles Part of the Marine Biology Commons, and the Oceanography and Atmospheric Sciences and Meteorology Commons NSUWorks Citation Charles R. Fisher, Paul A. Montagna, and Tracey Sutton. 2016. How Did the Deepwater Horizon Oil Spill Impact Deep-Sea Ecosystems? .Oceanography , (3) : 182 -195. https://nsuworks.nova.edu/occ_facarticles/784. This Article is brought to you for free and open access by the Department of Marine and Environmental Sciences at NSUWorks. It has been accepted for inclusion in Marine & Environmental Sciences Faculty Articles by an authorized administrator of NSUWorks. For more information, please contact [email protected]. OceTHE OFFICIALa MAGAZINEn ogOF THE OCEANOGRAPHYra SOCIETYphy CITATION Fisher, C.R., P.A. Montagna, and T.T. Sutton. 2016. How did the Deepwater Horizon oil spill impact deep-sea ecosystems? Oceanography 29(3):182–195, http://dx.doi.org/10.5670/oceanog.2016.82. DOI http://dx.doi.org/10.5670/oceanog.2016.82 COPYRIGHT This article has been published in Oceanography, Volume 29, Number 3, a quarterly journal of The Oceanography Society. Copyright 2016 by The Oceanography Society. All rights reserved. USAGE Permission is granted to copy this article for use in teaching and research.
    [Show full text]
  • A Review of Ocean/Sea Subsurface Water Temperature Studies from Remote Sensing and Non-Remote Sensing Methods
    water Review A Review of Ocean/Sea Subsurface Water Temperature Studies from Remote Sensing and Non-Remote Sensing Methods Elahe Akbari 1,2, Seyed Kazem Alavipanah 1,*, Mehrdad Jeihouni 1, Mohammad Hajeb 1,3, Dagmar Haase 4,5 and Sadroddin Alavipanah 4 1 Department of Remote Sensing and GIS, Faculty of Geography, University of Tehran, Tehran 1417853933, Iran; [email protected] (E.A.); [email protected] (M.J.); [email protected] (M.H.) 2 Department of Climatology and Geomorphology, Faculty of Geography and Environmental Sciences, Hakim Sabzevari University, Sabzevar 9617976487, Iran 3 Department of Remote Sensing and GIS, Shahid Beheshti University, Tehran 1983963113, Iran 4 Department of Geography, Humboldt University of Berlin, Unter den Linden 6, 10099 Berlin, Germany; [email protected] (D.H.); [email protected] (S.A.) 5 Department of Computational Landscape Ecology, Helmholtz Centre for Environmental Research UFZ, 04318 Leipzig, Germany * Correspondence: [email protected]; Tel.: +98-21-6111-3536 Received: 3 October 2017; Accepted: 16 November 2017; Published: 14 December 2017 Abstract: Oceans/Seas are important components of Earth that are affected by global warming and climate change. Recent studies have indicated that the deeper oceans are responsible for climate variability by changing the Earth’s ecosystem; therefore, assessing them has become more important. Remote sensing can provide sea surface data at high spatial/temporal resolution and with large spatial coverage, which allows for remarkable discoveries in the ocean sciences. The deep layers of the ocean/sea, however, cannot be directly detected by satellite remote sensors.
    [Show full text]
  • 8.1 the Significance of Ocean Deoxygenation for Mesopelagic Communities Brad A
    8.1 The significance of ocean deoxygenation for mesopelagic communities Brad A. Seibel and Karen F. Wishner 8.1 The significance of ocean deoxygenation for mesopelagic communities Brad A. Seibel1 and Karen F. Wishner2 1College of Marine Science, University of South Florida, Florida, USA. Email: [email protected] 2Graduate School of Oceanography, University of Rhode Island, Kingston, Rhode island, USA. Email: [email protected] Summary • Mesopelagic community structure is directly dependent on the availability of oxygen for aerobic metabolism. Diversity, abundance, distribution and composition of mesopelagic species are all influenced by variations in oxygen at both large and small scales. • Ocean deoxygenation will decrease the minimum oxygen content in the mesopelagic zone and cause oxyclines to shift vertically (i.e. expansion of the oxygen minimum zone (OMZ) core) in the water column. • A species’ ability to extract oxygen from sea water has evolved to meet specific oxygen demand. As a result, species do not have excess capacity, nor do they live in environments with excess oxygen relative to their evolved capacity; thus, they are susceptible to reductions in oxygen partial pressure and increasing temperature (which elevates metabolic demand). • Changes in temperature and oxygen profiles within the water column may therefore decouple or enhance competition among different mesopelagic zooplankton species and the larger predators that forage on them at depth by changing zooplankton abundances, distributions, and the depth of layers, and altering species composition and diversity. The biogeochemical cycles (i.e. the biological pump and microbial assemblages) that rely on the mesopelagic zooplankton community will be substantially altered. SECTION 8.1 SECTION Ocean deoxygenation: Everyone’s problem 265 8.1 The significance of ocean deoxygenation for mesopelagic communities Ocean hypoxia effect Potential consequences Decreasing oxygen partial pressure (PO2) in any • Reduced capacity for prey capture and predator habitat will reduce aerobic metabolic performance evasion.
    [Show full text]
  • Trophic Structure of Midwater Fishes Over Cold Seeps in the North Central Gulf of Mexico
    TROPHIC STRUCTURE OF MIDWATER FISHES OVER COLD SEEPS IN THE NORTH CENTRAL GULF OF MEXICO Jennifer P. McClain-Counts A Thesis Submitted to the University of North Carolina Wilmington in Partial Fulfillment of the Requirements for the Degree of Master of Science Center for Marine Science University of North Carolina Wilmington 2010 Approved by Advisory Committee Steve W. Ross Lawrence B. Cahoon Chair Joan W. Willey Accepted by Dean, Graduate School TABLE OF CONTENTS ABSTRACT....................................................................................................................... iv ACKNOWLEDGMENTS ................................................................................................. vi DEDICATION.................................................................................................................. vii LIST OF TABLES........................................................................................................... viii LIST OF FIGURES ........................................................................................................... xi INTRODUCTION ...............................................................................................................1 METHODS ..........................................................................................................................4 Study Area................................................................................................................4 Sample Collection ....................................................................................................5
    [Show full text]