CASE STUDY 2: Exploring Cold Seeps
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Inferences on Potential Seamount Locations from Mid-Resolution
T. Morato and D. Pauly (eds.), Seamounts: Biodiversity and Fisheries, Page 7 INFERENCES ON POTENTIAL SEAMOUNT LOCATIONS FROM MID- RESOLUTION BATHYMETRIC DATA Adrian Kitchingman and Sherman Lai Fisheries Centre, The University of British Columbia. 2259 Lower Mall, Vancouver, B.C., V6T 1Z4, Canada [email protected]; [email protected] ABSTRACT Seamounts are underwater volcanoes that did not grow tall enough to break to the sea surface and turn into islands. Once formed, seamounts tend to gradually sink under their own weight and the subsidence of the lithosphere. The ocean floor is littered with these former seamounts, here called ‘seamounds’. Seamounts occur throughout the world's oceans, but their number (which may surpass 50,000) is difficult to estimate, even roughly, because it depends on the resolution of the bathymetric map used and the specific definition of a seamount used, i.e., the limits used to distinguish between seamounts and seamounds. Here, the locations of a subset of the seamounts of the world were identified using two algorithms relying on the depth differences between adjacent cells of a digital global elevation map distributed by the U.S. National Oceanographic and Atmospheric Agency (NOAA). The overlap of both algorithms resulted in a set of about 14,000 seamounts, but a different number would have been found had we used different thresholds. Known seamount locations supplied by NOAA and SeamountsOnline (http://seamounts.sdsc.edu) were compared against the corresponding seamounts located by the study, which led to some degree of ground-truthing. The coordinates of the seamounts identified in this study are available on the CD-ROM attached to this report, and on http://www.seaaroundus.org. -
Hydrothermal Vents. Teacher's Notes
Hydrothermal Vents Hydrothermal Vents. Teacher’s notes. A hydrothermal vent is a fissure in a planet's surface from which geothermally heated water issues. They are usually volcanically active. Seawater penetrates into fissures of the volcanic bed and interacts with the hot, newly formed rock in the volcanic crust. This heated seawater (350-450°) dissolves large amounts of minerals. The resulting acidic solution, containing metals (Fe, Mn, Zn, Cu) and large amounts of reduced sulfur and compounds such as sulfides and H2S, percolates up through the sea floor where it mixes with the cold surrounding ocean water (2-4°) forming mineral deposits and different types of vents. In the resulting temperature gradient, these minerals provide a source of energy and nutrients to chemoautotrophic organisms that are, thus, able to live in these extreme conditions. This is an extreme environment with high pressure, steep temperature gradients, and high concentrations of toxic elements such as sulfides and heavy metals. Black and white smokers Some hydrothermal vents form a chimney like structure that can be as 60m tall. They are formed when the minerals that are dissolved in the fluid precipitates out when the super-heated water comes into contact with the freezing seawater. The minerals become particles with high sulphur content that form the stack. Black smokers are very acidic typically with a ph. of 2 (around that of vinegar). A black smoker is a type of vent found at depths typically below 3000m that emit a cloud or black material high in sulphates. White smokers are formed in a similar way but they emit lighter-hued minerals, for example barium, calcium and silicon. -
Introduction to Co2 Chemistry in Sea Water
INTRODUCTION TO CO2 CHEMISTRY IN SEA WATER Andrew G. Dickson Scripps Institution of Oceanography, UC San Diego Mauna Loa Observatory, Hawaii Monthly Average Carbon Dioxide Concentration Data from Scripps CO Program Last updated August 2016 2 ? 410 400 390 380 370 2008; ~385 ppm 360 350 Concentration (ppm) 2 340 CO 330 1974; ~330 ppm 320 310 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 Year EFFECT OF ADDING CO2 TO SEA WATER 2− − CO2 + CO3 +H2O ! 2HCO3 O C O CO2 1. Dissolves in the ocean increase in decreases increases dissolved CO2 carbonate bicarbonate − HCO3 H O O also hydrogen ion concentration increases C H H 2. Reacts with water O O + H2O to form bicarbonate ion i.e., pH = –lg [H ] decreases H+ and hydrogen ion − HCO3 and saturation state of calcium carbonate decreases H+ 2− O O CO + 2− 3 3. Nearly all of that hydrogen [Ca ][CO ] C C H saturation Ω = 3 O O ion reacts with carbonate O O state K ion to form more bicarbonate sp (a measure of how “easy” it is to form a shell) M u l t i p l e o b s e r v e d indicators of a changing global carbon cycle: (a) atmospheric concentrations of carbon dioxide (CO2) from Mauna Loa (19°32´N, 155°34´W – red) and South Pole (89°59´S, 24°48´W – black) since 1958; (b) partial pressure of dissolved CO2 at the ocean surface (blue curves) and in situ pH (green curves), a measure of the acidity of ocean water. -
Sea-Level Rise for the Coasts of California, Oregon, and Washington: Past, Present, and Future
Sea-Level Rise for the Coasts of California, Oregon, and Washington: Past, Present, and Future As more and more states are incorporating projections of sea-level rise into coastal planning efforts, the states of California, Oregon, and Washington asked the National Research Council to project sea-level rise along their coasts for the years 2030, 2050, and 2100, taking into account the many factors that affect sea-level rise on a local scale. The projections show a sharp distinction at Cape Mendocino in northern California. South of that point, sea-level rise is expected to be very close to global projections; north of that point, sea-level rise is projected to be less than global projections because seismic strain is pushing the land upward. ny significant sea-level In compliance with a rise will pose enor- 2008 executive order, mous risks to the California state agencies have A been incorporating projec- valuable infrastructure, devel- opment, and wetlands that line tions of sea-level rise into much of the 1,600 mile shore- their coastal planning. This line of California, Oregon, and study provides the first Washington. For example, in comprehensive regional San Francisco Bay, two inter- projections of the changes in national airports, the ports of sea level expected in San Francisco and Oakland, a California, Oregon, and naval air station, freeways, Washington. housing developments, and sports stadiums have been Global Sea-Level Rise built on fill that raised the land Following a few thousand level only a few feet above the years of relative stability, highest tides. The San Francisco International Airport (center) global sea level has been Sea-level change is linked and surrounding areas will begin to flood with as rising since the late 19th or to changes in the Earth’s little as 40 cm (16 inches) of sea-level rise, a early 20th century, when climate. -
Causes of Sea Level Rise
FACT SHEET Causes of Sea OUR COASTAL COMMUNITIES AT RISK Level Rise What the Science Tells Us HIGHLIGHTS From the rocky shoreline of Maine to the busy trading port of New Orleans, from Roughly a third of the nation’s population historic Golden Gate Park in San Francisco to the golden sands of Miami Beach, lives in coastal counties. Several million our coasts are an integral part of American life. Where the sea meets land sit some of our most densely populated cities, most popular tourist destinations, bountiful of those live at elevations that could be fisheries, unique natural landscapes, strategic military bases, financial centers, and flooded by rising seas this century, scientific beaches and boardwalks where memories are created. Yet many of these iconic projections show. These cities and towns— places face a growing risk from sea level rise. home to tourist destinations, fisheries, Global sea level is rising—and at an accelerating rate—largely in response to natural landscapes, military bases, financial global warming. The global average rise has been about eight inches since the centers, and beaches and boardwalks— Industrial Revolution. However, many U.S. cities have seen much higher increases in sea level (NOAA 2012a; NOAA 2012b). Portions of the East and Gulf coasts face a growing risk from sea level rise. have faced some of the world’s fastest rates of sea level rise (NOAA 2012b). These trends have contributed to loss of life, billions of dollars in damage to coastal The choices we make today are critical property and infrastructure, massive taxpayer funding for recovery and rebuild- to protecting coastal communities. -
Natural Variability of the Arctic Ocean Sea Ice During the Present Interglacial
Natural variability of the Arctic Ocean sea ice during the present interglacial Anne de Vernala,1, Claude Hillaire-Marcela, Cynthia Le Duca, Philippe Robergea, Camille Bricea, Jens Matthiessenb, Robert F. Spielhagenc, and Ruediger Steinb,d aGeotop-Université du Québec à Montréal, Montréal, QC H3C 3P8, Canada; bGeosciences/Marine Geology, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, 27568 Bremerhaven, Germany; cOcean Circulation and Climate Dynamics Division, GEOMAR Helmholtz Centre for Ocean Research, 24148 Kiel, Germany; and dMARUM Center for Marine Environmental Sciences and Faculty of Geosciences, University of Bremen, 28334 Bremen, Germany Edited by Thomas M. Cronin, U.S. Geological Survey, Reston, VA, and accepted by Editorial Board Member Jean Jouzel August 26, 2020 (received for review May 6, 2020) The impact of the ongoing anthropogenic warming on the Arctic such an extrapolation. Moreover, the past 1,400 y only encom- Ocean sea ice is ascertained and closely monitored. However, its pass a small fraction of the climate variations that occurred long-term fate remains an open question as its natural variability during the Cenozoic (7, 8), even during the present interglacial, on centennial to millennial timescales is not well documented. i.e., the Holocene (9), which began ∼11,700 y ago. To assess Here, we use marine sedimentary records to reconstruct Arctic Arctic sea-ice instabilities further back in time, the analyses of sea-ice fluctuations. Cores collected along the Lomonosov Ridge sedimentary archives is required but represents a challenge (10, that extends across the Arctic Ocean from northern Greenland to 11). Suitable sedimentary sequences with a reliable chronology the Laptev Sea were radiocarbon dated and analyzed for their and biogenic content allowing oceanographical reconstructions micropaleontological and palynological contents, both bearing in- can be recovered from Arctic Ocean shelves, but they rarely formation on the past sea-ice cover. -
Importance of Seamount-Like Features for Conserving Mediterranean Marine Habitats and Threatened Species
Nº. 1105 IMPORTANCE OF SEAMOUNT-LIKE FEATURES FOR CONSERVING MEDITERRANEAN MARINE HABITATS AND THREATENED SPECIES Ricardo Aguilar, Xavier Pastor, Silvia García & Pilar Marín Oceana. Leganitos, 47 - 28013 Madrid. Spain - *[email protected] INTRODUCTION HABITAT LOCATION MAIN SPECIES 16 of the more than 200 seamount‑like peaks in the Mediterranean1 have been observed using ROV. Coral reefs 4, 5, 6, 7 Lophelia pertusa, Madrepora oculata Desmophyllum dianthus, Stenocyathus vermiformis, The findings, which include carnivorous sponges, elasmobranches, coral gardens, sponge aggregations, Cold water corals All sites Caryophyllia spp. Pourtalosmilia anthophyllites, Javania caileti, coralligenous beds, as well as species new to science like the giant foraminifera Spiculosiphon oceana, Anomocora fecunda, Dendrophyllia spp. Paramuricea spp., Eunicella spp., Viminella flagellum, or new to the Mediterranean, like the scleractinian Anomocora fecunda, underscore the importance of 1, 2, 3, 4, 5, Callogorgia verticillata, Acanthogorgia spp., Placogorgia these geological features as hotspots and shelters/refuges species and habitats that are threatened, in Gorgonian/coral gardens: 6, 7, 8, 9, 11, coronata, Swiftia pallida, Muriceides lepida, Villogorgia regression, or rare in other Mediterranean areas. 12, 13, 14 bebrycoides, Bebryce mollis, Nicella granifera 1, 4, 5, 6, 7, Leiopathes glaberrima, Antipathes dichotoma, Antipathella METHODOLOGY Black corals Since 2006, Oceana has carried out six expeditions in the Mediterranean performing 129 ROV’s dives 9, 11, 15, 16 subpinnata, Parantipathes larix Isidella elongata, Pennatula spp., Pteroeides griseum, 2, 3, 4, 7, 8, over 16 seamounts, between ‑37 and ‑638 meters deep. Soft bottoms’ octocorals Virgularia mirabilis, Veretillun cynomorium, Kophobelemnon 9, 11, 14, 16 RESULTS stelliferum, Funiculina quadrangularis 2 3, 4, 5, 6, 7, Asconema setubalense, Phakellia spp., Axinella spp. -
OCEAN WARMING • the Ocean Absorbs Most of the Excess Heat from Greenhouse Gas Emissions, Leading to Rising Ocean Temperatures
NOVEMBER 2017 OCEAN WARMING • The ocean absorbs most of the excess heat from greenhouse gas emissions, leading to rising ocean temperatures. • Increasing ocean temperatures affect marine species and ecosystems. Rising temperatures cause coral bleaching and the loss of breeding grounds for marine fishes and mammals. • Rising ocean temperatures also affect the benefits humans derive from the ocean – threatening food security, increasing the prevalence of diseases and causing more extreme weather events and the loss of coastal protection. • Achieving the mitigation targets set by the Paris Agreement on climate change and limiting the global average temperature increase to well below 2°C above pre-industrial levels is crucial to prevent the massive, irreversible impacts of ocean warming on marine ecosystems and their services. • Establishing marine protected areas and putting in place adaptive measures, such as precautionary catch limits to prevent overfishing, can protect ocean ecosystems and shield humans from the effects of ocean warming. The distribution of excess heat in the ocean is not What is the issue? uniform, with the greatest ocean warming occurring in The ocean absorbs vast quantities of heat as a result the Southern Hemisphere and contributing to the of increased concentrations of greenhouse gases in subsurface melting of Antarctic ice shelves. the atmosphere, mainly from fossil fuel consumption. The Fifth Assessment Report published by the Intergovernmental Panel on Climate Change (IPCC) in 2013 revealed that the ocean had absorbed more than 93% of the excess heat from greenhouse gas emissions since the 1970s. This is causing ocean temperatures to rise. Data from the US National Oceanic and Atmospheric Administration (NOAA) shows that the average global sea surface temperature – the temperature of the upper few metres of the ocean – has increased by approximately 0.13°C per decade over the past 100 years. -
Chapter 51. Biological Communities on Seamounts and Other Submarine Features Potentially Threatened by Disturbance
Chapter 51. Biological Communities on Seamounts and Other Submarine Features Potentially Threatened by Disturbance Contributors: J. Anthony Koslow, Peter Auster, Odd Aksel Bergstad, J. Murray Roberts, Alex Rogers, Michael Vecchione, Peter Harris, Jake Rice, Patricio Bernal (Co-Lead members) 1. Physical, chemical, and ecological characteristics 1.1 Seamounts Seamounts are predominantly submerged volcanoes, mostly extinct, rising hundreds to thousands of metres above the surrounding seafloor. Some also arise through tectonic uplift. The conventional geological definition includes only features greater than 1000 m in height, with the term “knoll” often used to refer to features 100 – 1000 m in height (Yesson et al., 2011). However, seamounts and knolls do not appear to differ much ecologically, and human activity, such as fishing, focuses on both. We therefore include here all such features with heights > 100 m. Only 6.5 per cent of the deep seafloor has been mapped, so the global number of seamounts must be estimated, usually from a combination of satellite altimetry and multibeam data as well as extrapolation based on size-frequency relationships of seamounts for smaller features. Estimates have varied widely as a result of differences in methodologies as well as changes in the resolution of data. Yesson et al. (2011) identified 33,452 seamount and guyot features > 1000 m in height and 138,412 knolls (100 – 1000 m), whereas Harris et al. (2014) identified 10,234 seamount and guyot features, based on a stricter definition that restricted seamounts to conical forms. Estimates of total abundance range to >100,000 seamounts and to 25 million for features > 100 m in height (Smith 1991; Wessel et al., 2010). -
Coastal Upwelling Revisited: Ekman, Bakun, and Improved 10.1029/2018JC014187 Upwelling Indices for the U.S
Journal of Geophysical Research: Oceans RESEARCH ARTICLE Coastal Upwelling Revisited: Ekman, Bakun, and Improved 10.1029/2018JC014187 Upwelling Indices for the U.S. West Coast Key Points: Michael G. Jacox1,2 , Christopher A. Edwards3 , Elliott L. Hazen1 , and Steven J. Bograd1 • New upwelling indices are presented – for the U.S. West Coast (31 47°N) to 1NOAA Southwest Fisheries Science Center, Monterey, CA, USA, 2NOAA Earth System Research Laboratory, Boulder, CO, address shortcomings in historical 3 indices USA, University of California, Santa Cruz, CA, USA • The Coastal Upwelling Transport Index (CUTI) estimates vertical volume transport (i.e., Abstract Coastal upwelling is responsible for thriving marine ecosystems and fisheries that are upwelling/downwelling) disproportionately productive relative to their surface area, particularly in the world’s major eastern • The Biologically Effective Upwelling ’ Transport Index (BEUTI) estimates boundary upwelling systems. Along oceanic eastern boundaries, equatorward wind stress and the Earth s vertical nitrate flux rotation combine to drive a near-surface layer of water offshore, a process called Ekman transport. Similarly, positive wind stress curl drives divergence in the surface Ekman layer and consequently upwelling from Supporting Information: below, a process known as Ekman suction. In both cases, displaced water is replaced by upwelling of relatively • Supporting Information S1 nutrient-rich water from below, which stimulates the growth of microscopic phytoplankton that form the base of the marine food web. Ekman theory is foundational and underlies the calculation of upwelling indices Correspondence to: such as the “Bakun Index” that are ubiquitous in eastern boundary upwelling system studies. While generally M. G. Jacox, fi [email protected] valuable rst-order descriptions, these indices and their underlying theory provide an incomplete picture of coastal upwelling. -
Microbiology of Seamounts Is Still in Its Infancy
or collective redistirbution of any portion of this article by photocopy machine, reposting, or other means is permitted only with the approval of The approval portionthe ofwith any articlepermitted only photocopy by is of machine, reposting, this means or collective or other redistirbution This article has This been published in MOUNTAINS IN THE SEA Oceanography MICROBIOLOGY journal of The 23, Number 1, a quarterly , Volume OF SEAMOUNTS Common Patterns Observed in Community Structure O ceanography ceanography S BY DAVID EmERSON AND CRAIG L. MOYER ociety. © 2010 by The 2010 by O ceanography ceanography O ceanography ceanography ABSTRACT. Much interest has been generated by the discoveries of biodiversity InTRODUCTION S ociety. ociety. associated with seamounts. The volcanically active portion of these undersea Microbial life is remarkable for its resil- A mountains hosts a remarkably diverse range of unusual microbial habitats, from ience to extremes of temperature, pH, article for use and research. this copy in teaching to granted ll rights reserved. is Permission S ociety. ociety. black smokers rich in sulfur to cooler, diffuse, iron-rich hydrothermal vents. As and pressure, as well its ability to persist S such, seamounts potentially represent hotspots of microbial diversity, yet our and thrive using an amazing number or Th e [email protected] to: correspondence all end understanding of the microbiology of seamounts is still in its infancy. Here, we of organic or inorganic food sources. discuss recent work on the detection of seamount microbial communities and the Nowhere are these traits more evident observation that specific community groups may be indicative of specific geochemical than in the deep ocean. -
Sea Turtles : the Importance of Sea Turtles to Marine Ecosystems
PHOTO TIM CALVER WHY HEALTHY OCEANS NEED SEA TURTLES : THE IMPORTANCE OF SEA TURTLES TO MARINE ECOSYSTEMS Wilson, E.G., Miller, K.L., Allison, D. and Magliocca, M. oceana.org/seaturtles S E L T R U T Acknowledgements The authors would like to thank Karen Bjorndal for her review of this report. We would also like to thank The Streisand Foundation for their support of Oceana’s work to save sea turtles. PHOTO MICHAEL STUBBLEFIELD OCEANA | Protecting the World’s Oceans TABLE OF CONTENTS WHY HEALTHY OCEANS NEED SEA TURTLES 3 Executive Summary 4 U.S. Sea Turtles 5 Importance of Sea Turtles to Healthy Oceans 6 Maintaining Habitat Importance of Green Sea Turtles on Seagrass Beds Impact of Hawksbill Sea Turtles on Coral Reefs Benefit of Sea Turtles to Beach Dunes 9 Maintaining a Balanced Food Web Sea Turtles and Jellyfish Sea Turtles Provide Food for Fish 11 Nutrient Cycling Loggerheads Benefit Ocean Floor Ecosystems Sea Turtles Improve Nesting Beaches 12 Providing Habitat 14 The Risk of Ecological Extinction 15 Conclusions oceana.org/seaturtles 1 S E L T R U T PHOTO TIM CALVER 2 OCEANA | Protecting the World’s Oceans EXECUTIVE SUMMARY Sea turtles have played vital roles in maintaining the health of the world’s oceans for more than 100 million years. These roles range from maintaining productive coral reef ecosystems to transporting essential nutrients from the oceans to beaches and coastal dunes. Major changes have occurred in the oceans because sea turtles have been virtually eliminated from many areas of the globe. Commercial fishing, loss of nesting habitat and climate change are among the human-caused threats pushing sea turtles towards extinction.