DOCSLIB.ORG

The Ecological Importance of Deep Chlorophyll Maxima in The

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Ecological Importance of Deep Chlorophyll Maxima in The THE ECOLOGICAL IMPORTANCE OF DEEP CHLOROPHYLL MAXIMA IN THE LAURENTIAN GREAT LAKES A Dissertation Presented to the Faculty of the Graduate School of Cornell University In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy by Anne Scofield August 2018 © 2018 Anne Scofield THE ECOLOGICAL IMPORTANCE OF DEEP CHLOROPHYLL MAXIMA IN THE LAURENTIAN GREAT LAKES Anne Scofield, Ph. D. Cornell University 2018 Deep chlorophyll maxima (DCM) are common in stratified lakes and oceans, and phytoplankton growth in DCM can contribute significantly to total ecosystem production. Understanding the drivers of DCM formation is important for interpreting their ecological importance. The overall objective of this research was to assess the food web implications of DCM across a productivity gradient, using the Laurentian Great Lakes as a case study. First, I investigated the driving mechanisms of DCM formation and dissipation in Lake Ontario during April–September 2013 using in situ profile data and phytoplankton community structure. Results indicate that in situ growth was important for DCM formation in early- to mid-summer but settling and photoadaptation contributed to maintenance of the DCM late in the stratified season. Second, I expanded my analysis to all five of the Great Lakes using a time series generated by the US Environmental Protection Agency (EPA) long-term monitoring program in August from 1996-2017. The cross-lake comparison showed that DCM were closely aligned with deep biomass maxima (DBM) and dissolved oxygen saturation maxima (DOmax) in meso-oligotrophic waters (eastern Lake Erie and Lake Ontario), suggesting that DCM are productive features. In oligotrophic to ultra-oligotrophic waters (Lakes Michigan, Huron, Superior), however, DCM were deeper than the DBM and DOmax, indicating that photoadaptation was of considerable importance. Across lakes, euphotic depth was a significant predictor of both DCM depth and chlorophyll concentration, with greater water clarity associated with deeper and weaker DCM. Lastly, I investigated how DCM formation affects zooplankton diel vertical migration (DVM) by comparing the diel movements of different zooplankton size groups across three transects in southern Lake Michigan during summer 2015. Using taxonomy data from stratified net tows to inform our interpretation of laser optical plankton (LOPC) data, I concluded that phytoplankton distributions are an important determinant of zooplankton weighted mean depth. Trade-offs between optimal temperature, access to food resources, and predator avoidance contributed to differences in DVM among zooplankton size groups and regions of the lake. Overall, DCM production likely contributes significantly to phytoplankton biomass in oligotrophic lakes, causing selection pressure toward cold-adapted zooplankton that can effectively utilize DCM resources. BIOGRAPHICAL SKETCH Anne Scofield was born in Austin, TX and resided there until attending Stanford University. She completed her B.S. in Earth Systems with a concentration in Energy Sciences & Technology and a minor in Geological and Environmental Sciences. While at Stanford, she completed her first undergraduate research project through participation in the Stanford@SEA program – after which she decided to pursue marine science for her future studies. Her experience at Sea Education Association (SEA) inspired her to stay at Stanford University to complete a co-terminal M.S. degree in Earth Systems, during which she studied at Hopkins Marine Station in Monterey Bay, California. After her time at Stanford University, Annie went to work for Sea Education Association (SEA), where she taught oceanography and marine biology to undergraduate students through hands-on science at sea. When she was ready to go back to graduate school, serendipity landed her at Cornell University where she had the opportunity to work in the Laurentian Great Lakes. She was skeptical (at first) about making the switch to fresh water, but the research was intriguing, so she made the leap. The Great Lakes proved to be an exciting system study, and she thoroughly enjoyed her time doing research aboard the R/V Lake Guardian, at the Cornell Biological Field Station, and at Cornell University in Ithaca, NY. Annie is looking forward to starting a post-doctoral research position at Purdue University in the fall, where she will continue working in the Great Lakes system. iii I dedicate this dissertation to my parents and grandparents, who have always encouraged me to pursue my dreams, whatever they may be. Thank you for your love and support. Frank & Patricia Scofield William & Dorothy Bonham Frank & Alice Scofield iv ACKNOWLEDGMENTS This dissertation research was funded by the Great Lakes Fisheries Commission (2013_RUD_44029) and the Great Lakes Restoration Initiative, through grants from the USGS-Great Lakes Science Center (G13AC00064) and the U.S. Environmental Protection Agency (U.S. EPA) Cooperative Agreement to Cornell University (GL 00E01184-0). The research described in this dissertation has not been subjected to U.S. EPA review. Any opinions expressed in this publication are those of the authors and do not necessarily reflect the views or policies of the U.S. EPA. Any use of trade, product or firm names is for descriptive purposes only and does not imply endorsement by the U.S. EPA or USGS. I also acknowledge that Chapter 1 of this dissertation was previously published in the Journal of Great Lakes Research, published by Elsevier. I am incredibly grateful to the mentors, staff, and other graduate students who have provided both technical and moral support throughout my years working on this dissertation research. I have truly enjoyed working with my committee chair Dr. Lars Rudstam, who has a contagious enthusiasm for the work that he does has provided endless feedback and support during my graduate studies. He has been a wonderful advisor and I am grateful for his advice, patience, and the freedom he gave me to explore my scientific interests. I also have enjoyed our travels for conferences and the community he fosters at the Cornell Biological Field Station. I also extend a thank you to my other special committee members, Drs. Patrick Sullivan, Nelson Hairston, and Brian Weidel, who have provided valuable insights, feedback, and encouragement over the past few years. I appreciate that you all made time to chat and brainstorm about my work even when you were incredibly busy with other obligations. I also thank Dr. Jim Watkins for his input and contributions. I also grateful to the captains and crews of the R/V Lake Guardian and R/V Kaho, the technicians, graduate students, and staff at Cornell University, EPA GLNPO and v USGS that contributed to the data presented in this dissertation. This research would not have been possible without your efforts. Beyond the logical support, my friends at CBFS and my fellow Cornell graduate students have made my time here so much more meaningful through friendship and camaraderie – it has been a fantastic time! A huge thank you to my parents and my extended family – all of whom have been amazingly supportive of me throughout this process in good times and bad. I am grateful to them all for believing in me, cheering me on, and taking such an interest in what I do. It means the world to me. vi TABLE OF CONTENTS Biographical Sketch iii Dedication iv Acknowledgements v Preface viii The deep chlorophyll layer in Lake Ontario: extent, mechanisms Chapter 1 1 of formation, and abiotic predictors Testing theory of deep chlorophyll maxima formation Chapter 2 across a productivity gradient: a case study in the Laurentian 14 Great Lakes Variability in zooplankton diel vertical migrations Chapter 3 in Southern Lake Michigan 66 vii PREFACE Deep chlorophyll maxima (DCM) are common features in stratified lakes and oceans, and phytoplankton growth in DCM often contributes significantly to total system primary production. The primary mechanisms contributing to the formation of a DCM include growth of phytoplankton at depth due to increased nutrient availability, settling of phytoplankton cells at the thermocline, and photoadaptation (increased cell chlorophyll:carbon) of phytoplankton cells exposed to low-light environments (Camacho, 2006; Cullen, 1982). Understanding the drivers of DCM formation is needed to interpret its ecological importance as a food resource. The overall objective of this research was to improve our ability to assess the food web implications of various chlorophyll distributions observed across a productivity gradient, using the Laurentian Great Lakes as a case study. Motivation for this dissertation was initially driven by the need to better understand the importance of DCM in Lake Ontario. Lake Ontario has undergone significant changes in nutrient concentrations, water clarity, and epilimnetic chlorophyll over the past several decades, due to the combined effects of reduced nutrient loading since the 1972 Great Lakes Water Quality Agreement (GLWQA) and impacts of invasive dreissenid mussels (Dove, 2009; Holeck et al., 2015; Mills et al., 2003; Rudstam et al., 2017). Spring total phosphorus has decreased from over 20 μg/L in the late 1960s to between 7 and 10 μg/L as of the mid-1990s (Dove and Chapra, 2015; Holeck et al., 2015), while lake-wide average euphotic depth has increased by over 50% during that time (Binding et al., 2015). Concerns about increasing oligotrophy and potential consequences for higher trophic levels in Lake Ontario prompted an interest in studying viii whether the observed decreases in epilimnetic production might be offset by increased production in DCM. Although there was previous work describing the occurrence of the DCM during offshore Lake Ontario in summer (Watkins et al., 2015), the relative importance of various DCM-forming mechanisms had not thoroughly been assessed. To understand the potential bottom-up effects of the observed changes in Lake Ontario, we needed a more thorough understanding of DCM dynamics. To address these concerns, I investigated the driving mechanisms of DCM formation and dissipation in Lake Ontario during April–September 2013 using in situ profile data and phytoplankton community structure (Chapter 1).
Load more

Recommended publications
  • Mechanisms Contributing to the Deep Chlorophyll Maximum in Lake Superior
    Michigan Technological University Digital Commons @ Michigan Tech Dissertations, Master's Theses and Master's Dissertations, Master's Theses and Master's Reports - Open Reports 2011 Mechanisms contributing to the deep chlorophyll maximum in Lake Superior Marcel L. Dijkstra Michigan Technological University Follow this and additional works at: https://digitalcommons.mtu.edu/etds Part of the Civil and Environmental Engineering Commons Copyright 2011 Marcel L. Dijkstra Recommended Citation Dijkstra, Marcel L., "Mechanisms contributing to the deep chlorophyll maximum in Lake Superior", Master's Thesis, Michigan Technological University, 2011. https://doi.org/10.37099/mtu.dc.etds/231 Follow this and additional works at: https://digitalcommons.mtu.edu/etds Part of the Civil and Environmental Engineering Commons MECHANISMS CONTRIBUTING TO THE DEEP CHLOROPHYLL MAXIMUM IN LAKE SUPERIOR By Marcel L. Dijkstra A THESIS Submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE (Environmental Engineering) MICHIGAN TECHNOLOGICAL UNIVERSITY 2011 © 2011 Marcel L. Dijkstra This thesis, “Mechanisms Contributing to the Deep Chlorophyll Maximum in Lake Superior,” is hereby approved in partial fulfillment of the requirements for the Degree of MASTER OF SCIENCE IN ENVIRONMENTAL ENGINEERING. Department of Civil and Environmental Engineering Signatures: Thesis Advisor Dr. Martin Auer Department Chair Dr. David Hand Date Contents List of Figures ......................................................................................................
    [Show full text]
  • Glossary of Terms Used in Lake Almanor Water Quality Reports
    Glossary of Terms Used in Lake Almanor Water Quality Reports Algae. Algae (the plural form of alga) are one-celled plants that do not have a central vascular system for respiration and nutrient flow. Usually algae are very small, microscopic size. However, some are much larger, such a sea lettuce, but are still algae because each cell can survive on its own and there is no central vascular system. Various estimates indicate there are over 70,000 species of algae that inhabit fresh water. “Blue green algae”. These are more correctly Cyanobacteria, and not algae. The chlorophyll in each cell is spread throughout the entire cell. This contrasts with a true algae cell which has a firmer wall, like a pea, and the chlorophyll is in sacks called chloroplasts. Most of the harmful algae bloom (HAB) problems in US lakes are caused by only about 30 species of cyanobacteria. Cyanobacteria are found in many lakes and can destroy a lake's utility by producing potent toxins (cyanotoxins), taste, and odor in the lake water. The toxins can kill or harm humans that contact the lake water. Anoxic. Anoxic water has little or no measurable dissolved oxygen. Bloom. A "bloom" usually refers to excessive algal growth. Cladocera. Relatively large members of the zooplankton, such as Daphnia (water fleas), that are primarily filter feeders that eat algae and other phytoplankton. Coldwater Fishery. Waters in which the maximum mean monthly temperature generally does not exceed a certain value and, when other ecological factors are favorable, are capable of supporting year-round populations of cold water aquatic life, such as trout.
    [Show full text]
  • Pond and Lake Ecosystems a Pond Or Lake Ecosystem Includes Biotic
    Pond and Lake Ecosystems A pond or lake ecosystem includes biotic (living) plants, animals and micro-organisms, as well as abiotic (nonliving) physical and chemical interactions. Pond and lake ecosystems are a prime example of lentic ecosystems. Lentic refers to stationary or relatively still water, from the Latin lentus, which means sluggish. A typical lake has distinct zones of biological communities linked to the physical structure of the lake. (Figure below) The littoral zone is the near shore area where sunlight penetrates all the way to the sediment and allows aquatic plants (macrophytes) to grow. Light levels of about 1% or less of surface values usually define this depth. The 1% light level also defines the euphotic zone of the lake, which is the layer from the surface down to the depth where light levels become too low for photosynthesizers. In most lakes, the sunlit euphotic zone occurs within the epilimnion. However, in unusually transparent lakes, photosynthesis may occur well below the thermocline into the perennially cold hypolimnion. For example, in western Lake Superior near Duluth, MN, summertime algal photosynthesis and growth can persist to depths of at least 25 meters, while the mixed layer, or epilimnion, only extends down to about 10 meters. Ultra-oligotrophic Lake Tahoe, CA/NV, is so transparent that algal growth historically extended to over 100 meters, though its mixed layer only extends to about 10 meters in summer. Unfortunately, inadequate management of the Lake Tahoe basin since about 1960 has led to a significant loss of transparency due to increased algal growth and increased sediment inputs from stream and shoreline erosion.
    [Show full text]
  • Selph Et Al-2021.Pdf
    Journal of Plankton Research academic.oup.com/plankt Downloaded from https://academic.oup.com/plankt/advance-article/doi/10.1093/plankt/fbab006/6161505 by Florida State University Law Library user on 10 March 2021 J. Plankton Res. (2021) 1–20. doi:10.1093/plankt/fbab006 BLOOFINZ - Gulf of Mexico Phytoplankton community composition and biomass in the oligotrophic Gulf of Mexico KAREN E. SELPH1,*, RASMUS SWALETHORP2, MICHAEL R. STUKEL3,THOMASB.KELLY3, ANGELA N. KNAPP3, KELSEY FLEMING2, TABITHA HERNANDEZ2 AND MICHAEL R. LANDRY2 1department of oceanography, university of hawaii at manoa, 1000 pope road, honolulu, hi 96822, usa, 2scripps institution of oceanography, 9500 gilman drive, la jolla, ca 92093-0227, usa and 3department of earth, ocean and atmospheric science, florida state university, tallahassee, fl 32306, usa *corresponding author: [email protected] Received October 13, 2020; editorial decision January 10, 2021; accepted January 10, 2021 Corresponding editor: Lisa Campbell Biomass and composition of the phytoplankton community were investigated in the deep-water Gulf of Mexico (GoM) at the edges of Loop Current anticyclonic eddies during May 2017 and May 2018. Using flow cytometry, high-performance liquid chromatography pigments and microscopy, we found euphotic zone integrated chlorophyll aof ∼10 mg m−2 and autotrophic carbon ranging from 463 to 1268 mg m−2, dominated by picoplankton (<2μm cells). Phytoplankton assemblages were similar to the mean composition at the Bermuda Atlantic Time-series Study site, but differed from the Hawaii Ocean Times-series site. GoM phytoplankton biomass was ∼2-fold higher at the deep chlorophyll maximum (DCM) relative to the mixed layer (ML). Prochlorococcus and prymnesiophytes were the dominant taxa throughout the euphotic zone; however, other eukaryotic taxa had significant biomass in the DCM.
    [Show full text]
  • Variability in Epilimnion Depth Estimations in Lakes Harriet L
    https://doi.org/10.5194/hess-2020-222 Preprint. Discussion started: 10 June 2020 c Author(s) 2020. CC BY 4.0 License. Variability in epilimnion depth estimations in lakes Harriet L. Wilson1, Ana I. Ayala2, Ian D. Jones3, Alec Rolston4, Don Pierson2, Elvira de Eyto5, Hans- Peter Grossart6, Marie-Elodie Perga7, R. Iestyn Woolway1, Eleanor Jennings1 5 1Center for Freshwater and Environmental Studies, Dundalk Institute of Technology, Dundalk, Ireland 2Department of Ecology and Genetics, Limnology, Uppsala University, Uppsala, Sweden 3Biological and Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling, UK 4An Fóram Uisce, National Water Forum, Ireland 5Marine Institute, Furnace, Newport, Co. Mayo, Ireland 10 6Institute for Biochemistry and Biology, Potsdam University, Potsdam, Germany 7University of Lausanne, Faculty of Geoscience and Environment, CH 1015 Lausanne, Switzerland Correspondence to: Harriet L. Wilson ([email protected]) 15 Abstract. The “epilimnion” is the surface layer of a lake typically characterised as well-mixed and is decoupled from the “metalimnion” due to a rapid change in density. The concept of the epilimnion, and more widely, the three-layered structure of a stratified lake, is fundamental in limnology and calculating the depth of the epilimnion is essential to understanding many physical and ecological lake processes. Despite the ubiquity of the term, however, there is no objective or generic approach for defining the epilimnion and a diverse number of approaches prevail in the literature. Given the increasing 20 availability of water temperature and density profile data from lakes with a high spatio-temporal resolution, automated calculations, using such data, are particularly common, and have vast potential for use with evolving long-term, globally measured and modelled datasets.
    [Show full text]
  • Variability in Epilimnion Depth Estimations in Lakes
    Hydrol. Earth Syst. Sci., 24, 5559–5577, 2020 https://doi.org/10.5194/hess-24-5559-2020 © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License. Variability in epilimnion depth estimations in lakes Harriet L. Wilson1, Ana I. Ayala2, Ian D. Jones3, Alec Rolston4, Don Pierson2, Elvira de Eyto5, Hans-Peter Grossart6, Marie-Elodie Perga7, R. Iestyn Woolway1, and Eleanor Jennings1 1Centre for Freshwater and Environmental Studies, Dundalk Institute of Technology, Dundalk, Co. Louth, Ireland 2Department of Ecology and Genetics, Limnology, Uppsala University, Uppsala, Sweden 3Biological and Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling, UK 4An Fóram Uisce – The Water Forum, Nenagh, Co. Tipperary, Ireland 5Marine Institute Catchment Research Facility, Furnace, Newport, Co. Mayo, Ireland 6Institute for Biochemistry and Biology, Potsdam University, Potsdam, Germany 7University of Lausanne, Faculty of Geoscience and Environment, 1015 Lausanne, Switzerland Correspondence: Harriet L. Wilson ([email protected]) Received: 13 May 2020 – Discussion started: 10 June 2020 Revised: 22 September 2020 – Accepted: 5 October 2020 – Published: 24 November 2020 Abstract. The epilimnion is the surface layer of a lake typi- ter column structures, and vertical data resolution. These re- cally characterised as well mixed and is decoupled from the sults call into question the custom of arbitrary method se- metalimnion due to a steep change in density. The concept of lection and the potential problems this may cause for studies the epilimnion (and, more widely, the three-layered structure interested in estimating the ecological processes occurring of a stratified lake) is fundamental in limnology, and calcu- within the epilimnion, multi-lake comparisons, or long-term lating the depth of the epilimnion is essential to understand- time series analysis.
    [Show full text]
  • Eutrophication Parameters and Carlson-Type Trophic State Indices in Selected Pomeranian Lakes
    LimnologicalEutrophication Review (2011) parameters 11, 1: and 15-23 Carlson-type trophic state indices in selected Pomeranian lakes 15 DOI 10.2478/v10194-011-0023-3 Eutrophication parameters and Carlson-type trophic state indices in selected Pomeranian lakes Anna Jarosiewicz1*, Dariusz Ficek2, Tomasz Zapadka2 1Institute of Biology and Environmental Protection, Pomeranian Academy in Słupsk, Arciszewskiego 22B, 76-200 Słupsk, Poland; *e-mail: [email protected] 2Institute of Physics, Pomeranian Academy in Słupsk, Arciszewskiego 22B, 76-200 Słupsk, Poland Abstract: The objective of the study (2007-09) was to determine the current trophic state of eight selected lakes – Rybiec, Niezabyszewskie, Czarne, Chotkowskie, Obłęże, Jasień Południowy, Jasień Północny, Jeleń – based on Carlson-type indices (TSIs) and, to examine the relationship between the four calculated trophic state indices: TSI(SD), TSI(Chl), TSI(TP) and TSI(TN). Based on these values, it can be claimed that the trophy level of the lakes are within the mesotrophic and eutrophic states. It was observed that the values of the TSI(TP) in the analysed lakes are higher than the values of the indices calculated on the basis of the other variables. Moreover, the differences between the indices for particular lakes, suggest that in none of the analysed lakes is phosphorus a factor which limits algal productivity. Key words: eutrophication, trophic state index, lake, phosphorus, nitrogen Introduction ency extremes (0.06 m to 64 m) observed in nature (Carlson 1977). Each 10 units within this system rep- Determining the trophic condition of a lake is resents a half decrease in Secchi depth, a one-third an important step in the scientific assessment of each increase in chlorophyll concentration and a doubling lake.
    [Show full text]
  • Metalimnetic Oxygen Minimum in Green Lake, Wisconsin
    Michigan Technological University Digital Commons @ Michigan Tech Dissertations, Master's Theses and Master's Reports 2020 Metalimnetic Oxygen Minimum in Green Lake, Wisconsin Mahta Naziri Saeed Michigan Technological University, [email protected] Copyright 2020 Mahta Naziri Saeed Recommended Citation Naziri Saeed, Mahta, "Metalimnetic Oxygen Minimum in Green Lake, Wisconsin", Open Access Master's Thesis, Michigan Technological University, 2020. https://doi.org/10.37099/mtu.dc.etdr/1154 Follow this and additional works at: https://digitalcommons.mtu.edu/etdr Part of the Environmental Engineering Commons METALIMNETIC OXYGEN MINIMUM IN GREEN LAKE, WISCONSIN By Mahta Naziri Saeed A THESIS Submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE In Environmental Engineering MICHIGAN TECHNOLOGICAL UNIVERSITY 2020 © 2020 Mahta Naziri Saeed This thesis has been approved in partial fulfillment of the requirements for the Degree of MASTER OF SCIENCE in Environmental Engineering. Department of Civil and Environmental Engineering Thesis Advisor: Cory McDonald Committee Member: Pengfei Xue Committee Member: Dale Robertson Department Chair: Audra Morse Table of Contents List of figures .......................................................................................................................v List of tables ....................................................................................................................... ix Acknowledgements ..............................................................................................................x
    [Show full text]
  • Factors Controlling the Community Structure of Picoplankton in Contrasting Marine Environments
    Biogeosciences, 15, 6199–6220, 2018 https://doi.org/10.5194/bg-15-6199-2018 © Author(s) 2018. This work is distributed under the Creative Commons Attribution 4.0 License. Factors controlling the community structure of picoplankton in contrasting marine environments Jose Luis Otero-Ferrer1, Pedro Cermeño2, Antonio Bode6, Bieito Fernández-Castro1,3, Josep M. Gasol2,5, Xosé Anxelu G. Morán4, Emilio Marañon1, Victor Moreira-Coello1, Marta M. Varela6, Marina Villamaña1, and Beatriz Mouriño-Carballido1 1Departamento de Ecoloxía e Bioloxía Animal, Universidade de Vigo, Vigo, Spain 2Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas, Barcelona, Spain 3Departamento de Oceanografía, Instituto de investigacións Mariñas (IIM-CSIC), Vigo, Spain 4King Abdullah University of Science and Technology (KAUST), Read Sea Research Center, Biological and Environmental Sciences and Engineering Division, Thuwal, Saudi Arabia 5Centre for Marine Ecosystem Research, School of Sciences, Edith Cowan University, WA, Perth, Australia 6Centro Oceanográfico de A Coruña, Instituto Español de Oceanografía (IEO), A Coruña, Spain Correspondence: Jose Luis Otero-Ferrer ([email protected]) Received: 27 April 2018 – Discussion started: 4 June 2018 Revised: 4 October 2018 – Accepted: 10 October 2018 – Published: 26 October 2018 Abstract. The effect of inorganic nutrients on planktonic as- played a significant role. Nitrate supply was the only fac- semblages has traditionally relied on concentrations rather tor that allowed the distinction among the ecological
    [Show full text]
  • Subsurface Chlorophyll Maximum in August-September 1985 in the CLIMAX Area of the North Pacific
    W&M ScholarWorks VIMS Articles 1988 Subsurface chlorophyll maximum in August-September 1985 in the CLIMAX area of the North Pacific RW Eppley E Swift DG Redalje MR Landry LW Haas Virginia Institute of Marine Science Follow this and additional works at: https://scholarworks.wm.edu/vimsarticles Part of the Marine Biology Commons Recommended Citation Eppley, RW; Swift, E; Redalje, DG; Landry, MR; and Haas, LW, "Subsurface chlorophyll maximum in August- September 1985 in the CLIMAX area of the North Pacific" (1988). VIMS Articles. 226. https://scholarworks.wm.edu/vimsarticles/226 This Article is brought to you for free and open access by W&M ScholarWorks. It has been accepted for inclusion in VIMS Articles by an authorized administrator of W&M ScholarWorks. For more information, please contact [email protected]. MARINE ECOLOGY - PROGRESS SERIES Vol. 42: 289301, 1988 Published February 24 Mar. Ecol. Prog. Ser. Subsurface chlorophyll maximum in August-September 1985 in the CLIMAX area of the North Pacific ' Institute of Marine Resources, A-018, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093, USA Narragansett Marine Laboratory, University of Rhode Island, Kingston. Rhode Island 02881, USA Center for Marine Science, University of Southern Mississippi, National Space Technology Laboratories, NSTL, Mississippi 39529, USA Department of Oceanography, WB-10, University of Washington, Seattle, Washington 98195, USA Virginia Institute of Marine Science, College of William and Mary, Gloucester Point,
    [Show full text]
  • Deep Maxima of Phytoplankton Biomass, Primary Production and Bacterial Production in the Mediterranean Sea
    Biogeosciences, 18, 1749–1767, 2021 https://doi.org/10.5194/bg-18-1749-2021 © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. Deep maxima of phytoplankton biomass, primary production and bacterial production in the Mediterranean Sea Emilio Marañón1, France Van Wambeke2, Julia Uitz3, Emmanuel S. Boss4, Céline Dimier3, Julie Dinasquet5, Anja Engel6, Nils Haëntjens4, María Pérez-Lorenzo1, Vincent Taillandier3, and Birthe Zäncker6,7 1Department of Ecology and Animal Biology, Universidade de Vigo, 36310 Vigo, Spain 2Mediterranean Institute of Oceanography, Aix-Marseille Université, CNRS, Université de Toulon, CNRS, IRD, MIO UM 110, 13288 Marseille, France 3Laboratoire d’Océanographie de Villefranche, Sorbonne Université, CNRS, 06230 Villefranche-sur-Mer, France 4School of Marine Sciences, University of Maine, Orono, Maine, USA 5Scripps Institution of Oceanography, University of California, San Diego, San Diego, California, USA 6GEOMAR, Helmholtz Centre for Ocean Research Kiel, 24105 Kiel, Germany 7The Marine Biological Association of the United Kingdom, Plymouth, PL1 2PB, United Kingdom Correspondence: Emilio Marañón ([email protected]) Received: 7 July 2020 – Discussion started: 20 July 2020 Revised: 5 December 2020 – Accepted: 8 February 2021 – Published: 15 March 2021 Abstract. The deep chlorophyll maximum (DCM) is a ubiq- 10–15 mgCm−3 at the DCM. As a result of photoacclima- uitous feature of phytoplankton vertical distribution in strati- tion, there was an uncoupling between chlorophyll a-specific fied waters that is relevant to our understanding of the mech- and carbon-specific productivity across the euphotic layer. anisms that underpin the variability in photoautotroph eco- The ratio of fucoxanthin to total chlorophyll a increased physiology across environmental gradients and has impli- markedly with depth, suggesting an increased contribution cations for remote sensing of aquatic productivity.
    [Show full text]
  • A Baseline Study of the Oceanography of the Chagos Archipelago
    A Baseline Study of the Oceanography of the Chagos Archipelago Lewis Fasolo Honours Dissertation 1 ACKNOWLEDGEMENTS I would firstly like to acknowledge my supervisor Anya Waite for her wealth of knowledge that she so openly shared, and our consistent meetings that left me with a strong sense of direction. She went above and beyond, and was never out of reach. I would also like to thank my co-supervisor Jessica Meeuwig for her guidance, support and leadership during the three-week voyage through the Chagos Archipelago. Although her plate was full, she always made time to assist me. I was very impressed with her role as Research voyage leader. My thanks also go out to the crew and fellow scientists on board the Pacific Marlin for all their assistance. I was so fortunate to be a part of this unique voyage with a great group of people all wanting to achieve a common goal. It was an experience I will treasure and never forget. 2 ABSTRACT The Chagos Archipelago is a chain of islands, atolls, seamounts and shallow banks situated in the geographical centre of the tropical Indian Ocean, covering some 640,000km2. The region supports one of the healthiest marine ecosystems in the cleanest waters in the world. Investigating the oceanographic conditions within this no- take marine reserve will contribute to our global understanding of how the oceanic environment drives biodiversity in pristine tropical regions. This paper explores the first ever localised oceanography associated with shallow seamounts in the Chagos region. Over a three-week voyage, CTD casts and water samples to quantify chlorophyll-a values were conducted over high and low resolution transects throughout the archipelago to characterize vertical profiles regionally and across individual seamounts.
    [Show full text]