DOCSLIB.ORG

Migration Verticale Du Zooplancton Et Flux Respiratoire De Carbone En Mer De Beaufort (Arctique Canadien)

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Migration Verticale Du Zooplancton Et Flux Respiratoire De Carbone En Mer De Beaufort (Arctique Canadien) Migration verticale du zooplancton et flux respiratoire de carbone en mer de Beaufort (Arctique canadien) Thèse Gérald Darnis Doctorat en océanographie Philosophiæ Doctor (Ph.D.) Québec, Canada © Gérald Darnis, 2013 Résumé Le zooplancton exerce un rôle primordial dans les transferts d’énergie à travers les réseaux trophiques océaniques et dans le cycle biogéochimique du carbone des écosystèmes marins. La communauté entière recycle du CO2 en consommant le carbone photosynthétiquement fixé en surface, et en le respirant ensuite. Des migrateurs verticaux transportent du carbone stocké et le respirent en profondeur, contribuant à son exportation de la zone épipélagique. En Arctique, ce flux actif respiratoire n’a pas été mesuré, malgré un potentiel élevé de transport du à la forte contribution du migrateur saisonnier Calanus hyperboreus à la biomasse zooplanctonique. Cette thèse exploite une série quasi-annuelle de profils de biomasse et de respiration zooplanctoniques pour : (1) quantifier ce processus en mer de Beaufort; (2) améliorer les connaissances sur les fluctuations saisonnières de la distribution verticale de sept copépodes arctiques clés; et (3) suivre le cycle biologique de C. hyperboreus. Ce grand herbivore constituait 45 % de la biomasse zooplanctonique et a effectué les migrations verticales les plus extensives. Son ascension saisonnière, de l’ordre de 200 m, et celles de moindre ampleur de C. glacialis et du petit omnivore Oithona similis, ont coïncidé avec les efflorescences d’algues de glace et phytoplanctoniques. Malgré une reproduction hivernale vigoureuse en profondeur, une débâcle hâtive de la banquise, et une production primaire élevée, un faible recrutement au stade copépodite a entrainé une stagnation de la croissance de la population de C. hyperboreus. Très abondant, l’omnivore Metridia longa, et Microcalanus pygmaeus, ont pu exercer dans leur habitat mésopélagique un contrôle sur cette population en interceptant les œufs de C. hyperboreus flottant vers la surface. Le cryophile Pseudocalanus spp. est resté en permanence dans la zone épipélagique froide, tandis que le mésopélagique Triconia borealis, possiblement un semi-parasite de C. hyperboreus, était associé avec dans la couche Atlantique plus chaude. La température a eu peu d’effet sur les déplacements verticaux des copépodes arctiques. Le grand zooplancton, dominé par les Calanus, était responsable de 89% du broutage zooplanctonique de la production primaire brute d’avril à juillet. Les transports de carbone au delà de 100 m et 200 m par ces Calanus étaient du même ordre de grandeur que les flux gravitationnels de carbone organique particulaire à ces profondeurs. Ces résultats soulignent l’importance d’inclure le transport actif dû aux migrateurs saisonniers du grand zooplancton dans les bilans de carbone de l’Océan Arctique. iii Abstract Zooplankton play a pivotal role in the energy transfer through the oceanic food webs and in the biogeochemical carbon cycle within marine ecosystems. The entire community recycles CO2 by consuming photosynthetically fixed carbon and respiring it thereafter. Vertical migrants transport stored carbon and respire it at depth, thus, contributing to its export from the epipelagic zone. Active respiratory flux has not been measured in the Arctic despite the high potential for transport due to the strong contribution of the seasonal migrant Calanus hyperboreus to zooplankton biomass. This thesis exploits a quasi-annual time series of zooplankton biomass and respiration profiles to: (1) quantify this process in the Beaufort Sea; (2) improve our knowledge on the seasonal fluctuations of the vertical distribution of seven key arctic copepods; and (3) track the life cycle of Calanus hyperboreus. This large herbivore contributed 45% to the zooplankton biomass and performed the most extensive vertical migration. Its seasonal ascent, ranging about 200 m, and those of lesser magnitude of C. glacialis and the small omnivore Oithona similis, coincided with the ice algae and phytoplankton blooms. Despite vigorous winter reproduction at depth, a precocious ice break-up, and high spring-summer primary production, weak recruitment to copepodite stage caused C. hyperboreus population growth to stagnate. In their mesopelagic habitat, the highly abundant omnivore Metridia longa, and Microcalanus pygmaeus, could have exerted a control on this population by intercepting C. hyperboreus eggs floating toward the surface. The cryophilic Pseudocalanus spp. remained year-round in the cold epipelagic zone while the mesopelagic Triconia borealis, likely a semi-parasite of C. hyperboreus, was associated with it in the warmer Atlantic layer. Temperature had little effect on the vertical displacements of arctic copepods. The Calanus-dominated large zooplankton was responsible for 89% of zooplankton grazing on the April-July gross primary production. Carbon transport below 100 m and 200 m depth, mediated by the Calanus species, was of the same magnitude as the gravitational fluxes of particulate organic carbon to these depths. These results stress the importance of including active transport by large zooplankton migrants in carbon budgets of the Arctic Ocean. v Table des matières Résumé .................................................................................................................................. iii Abstract ................................................................................................................................... v Table des matières ............................................................................................................... vii Liste des tableaux ................................................................................................................... xi Liste des figures .................................................................................................................. xiii Remerciements ..................................................................................................................... xix Avant-propos ....................................................................................................................... xxi 1. Chapitre 1 - Introduction générale .................................................................................... 1 1.1 Le rôle des océans dans le cycle global du carbone .................................................. 1 1.2 Fonctionnement de la pompe biologique de CO2 ...................................................... 3 1.3 Rôle du zooplancton dans le flux gravitationnel (passif) de carbone ........................ 4 1.4 Rôle du zooplancton dans le flux actif de carbone .................................................... 7 1.4.1 Migrations verticales du zooplancton ................................................................. 7 1.4.2 Modalités du flux actif ........................................................................................ 8 1.4.3 Mesure du flux actif dans les systèmes arctiques ............................................... 9 1.5 L’écosystème marin arctique ................................................................................... 11 1.5.1 Configurations géographique et océanographique ........................................... 11 1.5.2 Réseaux trophiques pélagiques arctiques ......................................................... 13 1.6 Le zooplancton arctique de la mer de Beaufort ....................................................... 16 1.6.1 Composition taxonomique et trophique ............................................................ 16 1.6.2 Migrations verticales ......................................................................................... 19 1.6.3 Le complexe d’espèces Calanus ....................................................................... 21 1.7 L’écosystème marin arctique face aux effets du réchauffement climatique ............ 22 1.8 Objectifs de recherche ............................................................................................. 25 2. Chapitre 2 – Food, temperature and the seasonal vertical migration of key copepods in the thermally stratified Amundsen Gulf (Beaufort Sea, Arctic Ocean) ................................ 27 2.1. Résumé .................................................................................................................... 27 2.2. Abstract ................................................................................................................... 28 2.3. Introduction ............................................................................................................. 29 2.4. Material and methods .............................................................................................. 30 2.4.1 Study area and oceanographic setting ............................................................... 30 2.4.2 Sampling ........................................................................................................... 30 2.4.3 Zooplankton taxonomy and biomass ................................................................ 31 2.4.4 Vertical distribution .......................................................................................... 31 2.5. Results ..................................................................................................................... 32 2.5.1 Sea-ice, temperature, and microalgal production ............................................. 32 2.5.2 Time-depth sections of copepod biomass by species ......................................
Load more

Recommended publications
  • Meddelelser120.Pdf (2.493Mb)
    MEDDELELSER NR. 120 IAN GJERTZ & BERIT MØRKVED Environmental Studies from Franz Josef Land, with Emphasis on Tikhaia Bay, Hooker Island '-,.J��!c �"'oo..--------' MikhalSkakuj NORSK POLARINSTITUTT OSLO 1992 ISBN 82-7666-043-6 lan Gjertz and Berit Mørkved Printed J uly 1992 Norsk Polarinstitutt Cover picture: Postboks 158 Iceberg of Franz Josef Land N-1330 Oslo Lufthavn (Ian Gjertz) Norway INTRODUCTION The Russian high Arctic archipelago Franz Josef Land has long been closed to foreign scientists. The political changes which occurred in the former Soviet Union in the last part of the 1980s resulted in the opening of this area to foreigners. Director Gennady Matishov of Murmansk Marine Biological Institute deserves much of the credit for this. In 1990 an international cooperation was established between the Murmansk Marine Biological Institute (MMBI); the Arctic Ecology Group of the Institute of Oceanology, Gdansk; and the Norwegian Polar Research Institute, Oslo. The purpose of this cooperation is to develope scientific cooperation in the Arctic thorugh joint expeditions, the establishment of a high Arctic scientific station, and the exchange of scientific information. So far the results of this cooperation are two scientific cruises with the RV "Pomor", a vessel belonging to the MMBI. The cruises have been named Sov­ Nor-Poll and Sov-Nor-Po12. A third cruise is planned for August-September 1992. In addition the MMBI has undertaken to establish a scientific station at Tikhaia Bay on Hooker Island. This is the site of a former Soviet meteorological base from 1929-1958, and some of the buildings are now being restored by MMBI.
    [Show full text]
  • Egg Production Rates of the Copepod Calanus Marshallae in Relation To
    Egg production rates of the copepod Calanus marshallae in relation to seasonal and interannual variations in microplankton biomass and species composition in the coastal upwelling zone off Oregon, USA Peterson, W. T., & Du, X. (2015). Egg production rates of the copepod Calanus marshallae in relation to seasonal and interannual variations in microplankton biomass and species composition in the coastal upwelling zone off Oregon, USA. Progress in Oceanography, 138, 32-44. doi:10.1016/j.pocean.2015.09.007 10.1016/j.pocean.2015.09.007 Elsevier Version of Record http://cdss.library.oregonstate.edu/sa-termsofuse Progress in Oceanography 138 (2015) 32–44 Contents lists available at ScienceDirect Progress in Oceanography journal homepage: www.elsevier.com/locate/pocean Egg production rates of the copepod Calanus marshallae in relation to seasonal and interannual variations in microplankton biomass and species composition in the coastal upwelling zone off Oregon, USA ⇑ William T. Peterson a, , Xiuning Du b a NOAA-Fisheries, Northwest Fisheries Science Center, Hatfield Marine Science Center, Newport, OR, United States b Cooperative Institute for Marine Resources Studies, Oregon State University, Hatfield Marine Science Center, Newport, OR, United States article info abstract Article history: In this study, we assessed trophic interactions between microplankton and copepods by studying Received 15 May 2015 the functional response of egg production rates (EPR; eggs femaleÀ1 dayÀ1) of the copepod Calanus Received in revised form 1 August 2015 marshallae to variations in microplankton biomass, species composition and community structure. Accepted 17 September 2015 Female C. marshallae and phytoplankton water samples were collected biweekly at an inner-shelf station Available online 5 October 2015 off Newport, Oregon USA for four years, 2011–2014, during which a total of 1213 female C.
    [Show full text]
  • Evolutionary History of Inversions in the Direction of Architecture-Driven
    bioRxiv preprint doi: https://doi.org/10.1101/2020.05.09.085712; this version posted May 10, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC 4.0 International license. Evolutionary history of inversions in the direction of architecture- driven mutational pressures in crustacean mitochondrial genomes Dong Zhang1,2, Hong Zou1, Jin Zhang3, Gui-Tang Wang1,2*, Ivan Jakovlić3* 1 Key Laboratory of Aquaculture Disease Control, Ministry of Agriculture, and State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China. 2 University of Chinese Academy of Sciences, Beijing 100049, China 3 Bio-Transduction Lab, Wuhan 430075, China * Corresponding authors Short title: Evolutionary history of ORI events in crustaceans Abbreviations: CR: control region, RO: replication of origin, ROI: inversion of the replication of origin, D-I skew: double-inverted skew, LBA: long-branch attraction bioRxiv preprint doi: https://doi.org/10.1101/2020.05.09.085712; this version posted May 10, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC 4.0 International license. Abstract Inversions of the origin of replication (ORI) of mitochondrial genomes produce asymmetrical mutational pressures that can cause artefactual clustering in phylogenetic analyses. It is therefore an absolute prerequisite for all molecular evolution studies that use mitochondrial data to account for ORI events in the evolutionary history of their dataset.
    [Show full text]
  • A Systematic and Experimental Analysis of Their Genes, Genomes, Mrnas and Proteins; and Perspective to Next Generation Sequencing
    Crustaceana 92 (10) 1169-1205 CRUSTACEAN VITELLOGENIN: A SYSTEMATIC AND EXPERIMENTAL ANALYSIS OF THEIR GENES, GENOMES, MRNAS AND PROTEINS; AND PERSPECTIVE TO NEXT GENERATION SEQUENCING BY STEPHANIE JIMENEZ-GUTIERREZ1), CRISTIAN E. CADENA-CABALLERO2), CARLOS BARRIOS-HERNANDEZ3), RAUL PEREZ-GONZALEZ1), FRANCISCO MARTINEZ-PEREZ2,3) and LAURA R. JIMENEZ-GUTIERREZ1,5) 1) Sea Science Faculty, Sinaloa Autonomous University, Mazatlan, Sinaloa, 82000, Mexico 2) Coelomate Genomic Laboratory, Microbiology and Genetics Group, Industrial University of Santander, Bucaramanga, 680007, Colombia 3) Advanced Computing and a Large Scale Group, Industrial University of Santander, Bucaramanga, 680007, Colombia 4) Catedra-CONACYT, National Council for Science and Technology, CDMX, 03940, Mexico ABSTRACT Crustacean vitellogenesis is a process that involves Vitellin, produced via endoproteolysis of its precursor, which is designated as Vitellogenin (Vtg). The Vtg gene, mRNA and protein regulation involve several environmental factors and physiological processes, including gonadal maturation and moult stages, among others. Once the Vtg gene, mRNAs and protein are obtained, it is possible to establish the relationship between the elements that participate in their regulation, which could either be species-specific, or tissue-specific. This work is a systematic analysis that compares the similarities and differences of Vtg genes, mRNA and Vtg between the crustacean species reported in databases with respect to that obtained from the transcriptome of Callinectes arcuatus, C. toxotes, Penaeus stylirostris and P. vannamei obtained with MiSeq sequencing technology from Illumina. Those analyses confirm that the Vtg obtained from selected species will serve to understand the process of vitellogenesis in crustaceans that is important for fisheries and aquaculture. RESUMEN La vitelogénesis de los crustáceos es un proceso que involucra la vitelina, producida a través de la endoproteólisis de su precursor llamado Vitelogenina (Vtg).
    [Show full text]
  • Fishery Bulletin/U S Dept of Commerce National Oceanic
    NEW RECORDS OF ELLOBIOPSIDAE (PROTISTA (INCERTAE SEDIS» FROM THE NORTH PACIFIC WITH A DESCRIPTION OF THALASSOMYCES ALBATROSSI N.SP., A PARASITE OF THE MYSID STILOMYSIS MAJOR BRUCE L. WINGl ABSTRACT Ten species of ellobiopsids are currently known to occur in the North Pacific Ocean-three on mysids and seven on other crustaceans. Thalassomyces boschmai parasitizes mysids of genera Acanthomysis, Neomysis, and Meterythrops from the coastal waters of Alaska, British Columbia, and Washington. Thalassomyces albatrossi n.sp. is described as a parasite of Stilomysis major from Korea. Thalassomyces fasciatus parasitizes the pelagic mysids Gnathophausia ingens and G. gracilis from Baja California and southern California. Thalassomyces marsupii parasitizes the hyperiid amphipods Parathemisto pacifica and P. libellula and the lysianassid amphipod Cypho­ caris challengeri in the northeastern Pacific. Thalassomyces fagei parasitizes euphausiids of the genera Euphausia and Thysanoessa in the northeastern Pacific from the southern Chukchi Sea to southern California, and occurs off the coast of Japan in the western Pacific. Thalassomyces capillosus parasitizes the decapod shrimp Pasiphaea pacifica in the northeastern Pacific from Alaska to Oregon, while Thalassomyces californiensis parasitizes Pasiphaea emarginata from central California. An eighth species of Thalassomyces parasitizing pasiphaeid shrimp from Baja California remains undescribed. Ellobiopsis chattoni parasitizes the calanoid copepods Metridia longa and Pseudocalanus minutus in the coastal waters of southeastern Alaska. Ellobiocystis caridarum is found frequently on the mouth parts ofPasiphaea pacifica from southeastern Alaska. An epibiont closely resembling Ellobiocystis caridarum has been found on the benthic gammarid amphipod Rhachotropis helleri from Auke Bay, Alaska. Where sufficient data are available, notes on variability, seasonal occurrence, and effects on the hosts are presented for each species of ellobiopsid.
    [Show full text]
  • How Including Ecological Realism Impacts the Assessment of the Environmental Effect of Oil Spills at the Population Level: the A
    How including ecological realism impacts the assessment of the environmental effect of oil spills at the population level: The application of matrix models for Arctic Calanus species de Vries, P., Tamis, J., Hjorth, M., Jak, R., Falk-Petersen, S., van den Heuvel- Greve, M., ... Hemerik, L. This is a "Post-Print" accepted manuscript, which has been published in "Marine Environmental Research" This version is distributed under a non-commercial no derivatives Creative Commons (CC-BY-NC-ND) user license, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited and not used for commercial purposes. Further, the restriction applies that if you remix, transform, or build upon the material, you may not distribute the modified material. Please cite this publication as follows: de Vries, P., Tamis, J., Hjorth, M., Jak, R., Falk-Petersen, S., van den Heuvel-Greve, M., ... Hemerik, L. (2018). How including ecological realism impacts the assessment of the environmental effect of oil spills at the population level: The application of matrix models for Arctic Calanus species. Marine Environmental Research, 141, 264- 274. DOI: 10.1016/j.marenvres.2018.09.008 You can download the published version at: https://doi.org/10.1016/j.marenvres.2018.09.008 Accepted Manuscript How including ecological realism impacts the assessment of the environmental effect of oil spills at the population level: The application of matrix models for Arctic Calanus species Pepijn de Vries, Jacqueline Tamis, Morten Hjorth, Robbert
    [Show full text]
  • Hidden Food in the Coldest of Times the NUTRIENT ROLE of SEA ICE Copepods, Tiny Lipid-Rich Obtaining Sufficient Food Under Fig
    UNDERSTANDING ECOSYSTEM PROCESSES IN THE BERING SEA 2007–2013 Hidden Food in the Coldest of Times THE NUTRIENT ROLE OF SEA ICE Copepods, tiny lipid-rich obtaining sufficient food under Fig. 1 crustaceans in the Bering Sea, the ice to initiate feeding and are a favored meal of larval and reproduction. A second question juvenile Pollock. One copepod is “what is this food source”? One that dominates the zooplankton possibility was the layer of ice on the Bering Sea shelf, and shelf algae—a diverse community of areas around the Arctic Ocean, microscopic plants and animals is Calanus glacialis (Figure 1). that grow under the ice during We know that the abundance of spring (Figure 2)—rather than this species fluctuates between from the more usual phytoplank- years. Surprisingly, colder years, ton community in the water when ice cover is more extensive column beneath. and persists longer during spring, appear to favor growth of the How We Did It copepod population. Why is this? We collected zooplankton We set out to answer this ques- samples to see what the C. glacialis Fig. 2 tion during a cruise in late winter population was doing, whether of 2009 through early spring of the adult females were laying eggs 2010, when ice covered most of or not, and how much food was the Bering Sea shelf. in their guts. We determined the Since reproduction and identity of individual prey spe- growth of this copepod is con- cies in their guts from their DNA trolled by the availability of food, and quantified the amount of this we thought that they must be continued on page 2 The Big Picture The high feeding rates of the copepod Calanus glacialis that we observed during a cruise in late Blocks of sea ice turned winter and early spring of 2009/2010 could not have been sustained by the low levels of phyto- upside down to reveal plankton in the water column.
    [Show full text]
  • Tautuglugu Uvani PDF Mi Makpiraanmi
    KANATAUP UKIUQTAQTUNGATA TARIURMIUTANUT NUNANNGUAQ Taanna Nunannguaq kiinaujaqaqtitaujuq ilangani Gordon amma Betty Moore Katujjiqatigiinik. I | Atuqujaujuq takujaujunnarluni: Tariurjualirijikkut Ukiuqtaqtumi Atutsiarnirmut Katujjiqatigiit, Nunarjuarmi Uumajulirijikkut Kiinajangit Kanatami, amma Mitilirijikkut Kanatami. (2018). Kanataup Ukiuqtaqtungata Tariurmiutanut Nunannguaq. Aatuvaa, Antiariu: Tariurjualirijikkut Ukiuqtaqtumi Atutsiarnirmut Katujjiqatigiit. Qaangata ajjinnguanga: Siarnaulluni Nunannguaq Kanataup Ukiuqtaqtungani taassuma Jeremy Davies Iluaniittuq: Nalunaijaqsimattiaqtuq Kanataup Ukiuqtaqtungani Tamanna piliriangujuq laisansiqaqtuq taakuatigut Creative Commons Attribution-NonCommercial 4.0 Nunarjuarmi Laisansi. Taasumaa laisansimi takugumaguvit, uvungarluti http://creativecommons.org/licenses/by-nc/4.0 uvvaluunniit uvunga titirarlutit Creative Commons, PO Box 1866, Mountain View, CA 94042, USA. Ajjinngualimaat © ajjiliurijinut Naasautinga (ISBN): 978-1-7752749-0-2 (paippaamut saqqititat) Naasautinga (ISBN): 978-1-7752749-1-9 (qarasaujatigut saqqititat) Uqalimaagaqarvik amma Tuqquqtausimavik Kanatami AJJIGIINNGITTUT Paippaat kamattiaqtuninngaaqsimajut Paippaarmuuqtajut Kanatami, Vivvuali 2018 100% Pauqititsijunnanngittuq Saqqititaq taassuma Hemlock Saqqititsijikkunnu © 1986 Paannti nalunaikkutaq WWF-Nunarjualimaami Kinaujaqarvik Uumajunut (qaujimajaungmijuq Nunarjualimaamit Uumajunut Kinaujaqarvik). ® “WWF” taanaujuq WWF Atiliuqatausimajuq Ilisarijaulluni. Tunuaniittuq Ajjinnguanga: Imarmiutait piruqtut attatiqanngittut
    [Show full text]
  • Bioluminescence As an Ecological Factor During High Arctic Polar Night Heather A
    www.nature.com/scientificreports OPEN Bioluminescence as an ecological factor during high Arctic polar night Heather A. Cronin1, Jonathan H. Cohen1, Jørgen Berge2,3, Geir Johnsen3,4 & Mark A. Moline1 Bioluminescence commonly infuences pelagic trophic interactions at mesopelagic depths. Here receie: 01 pri 016 we characterize a vertical gradient in structure of a generally low species diversity bioluminescent ccepte: 14 Octoer 016 community at shallower epipelagic depths during the polar night period in a high Arctic ford with in Puise: 0 oemer 016 situ bathyphotometric sampling. Bioluminescence potential of the community increased with depth to a peak at 80 m. Community composition changed over this range, with an ecotone at 20–40 m where a dinofagellate-dominated community transitioned to dominance by the copepod Metridia longa. Coincident at this depth was bioluminescence exceeding atmospheric light in the ambient pelagic photon budget, which we term the bioluminescence compensation depth. Collectively, we show a winter bioluminescent community in the high Arctic with vertical structure linked to attenuation of atmospheric light, which has the potential to infuence pelagic ecology during the light-limited polar night. Light and vision play a large role in interactions among organisms in both the epipelagic (0–200 m) and mesope- lagic (200–1000 m) realms1,2. Eye structure and function in these habitats is commonly adapted for photon capture in the underwater light feld, with increasing specialization in the mesopelagic3. To avoid visual detection, species in epi- and mesopelagic habitats employ cryptic strategies such as transparency4 and counter-illumination5,6, along with diel vertical migration7,8, to remain hidden from potential predators.
    [Show full text]
  • Canada's Arctic Marine Atlas
    CANADA’S ARCTIC MARINE ATLAS This Atlas is funded in part by the Gordon and Betty Moore Foundation. I | Suggested Citation: Oceans North Conservation Society, World Wildlife Fund Canada, and Ducks Unlimited Canada. (2018). Canada’s Arctic Marine Atlas. Ottawa, Ontario: Oceans North Conservation Society. Cover image: Shaded Relief Map of Canada’s Arctic by Jeremy Davies Inside cover: Topographic relief of the Canadian Arctic This work is licensed under the Creative Commons Attribution-NonCommercial 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc/4.0 or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA. All photographs © by the photographers ISBN: 978-1-7752749-0-2 (print version) ISBN: 978-1-7752749-1-9 (digital version) Library and Archives Canada Printed in Canada, February 2018 100% Carbon Neutral Print by Hemlock Printers © 1986 Panda symbol WWF-World Wide Fund For Nature (also known as World Wildlife Fund). ® “WWF” is a WWF Registered Trademark. Background Image: Phytoplankton— The foundation of the oceanic food chain. (photo: NOAA MESA Project) BOTTOM OF THE FOOD WEB The diatom, Nitzschia frigida, is a common type of phytoplankton that lives in Arctic sea ice. PHYTOPLANKTON Natural history BOTTOM OF THE Introduction Cultural significance Marine phytoplankton are single-celled organisms that grow and develop in the upper water column of oceans and in polar FOOD WEB The species that make up the base of the marine food Seasonal blooms of phytoplankton serve to con- sea ice. Phytoplankton are responsible for primary productivity—using the energy of the sun and transforming it via pho- web and those that create important seafloor habitat centrate birds, fishes, and marine mammals in key areas, tosynthesis.
    [Show full text]
  • Vertical Distribution of Calanus Spp. and Metridia Longa at Four Arctic Locations
    Marine Biology Research, 2008; 4: 193Á207 ORIGINAL ARTICLE Vertical distribution of Calanus spp. and Metridia longa at four Arctic locations MALIN DAASE1, KETIL EIANE1,3, DAG L. AKSNES2 & DANIEL VOGEDES1 1The University Centre in Svalbard, Longyearbyen, Norway, 2Department of Biology, University of Bergen, Bergen, Norway, and 3The University College in Bodø, Norway Abstract We investigated the vertical distribution of Calanus finmarchicus, C. glacialis, C. hyperboreus and Metridia longa at four locations around the archipelago of Svalbard in autumn. The older and larger copepodites of Calanus spp. were generally located deeper in the water column. Differences in vertical distribution between stations partly reflected a southÁnorth gradient in developmental progress with higher abundance of older stages in the southern locations. The C. finmarchicus and M. longa observations were consistent with the hypothesis that the developmental stages distributed according to certain preferences for light intensity, and different optical properties at the four locations are likely to have affected the vertical distributions. Diel vertical migration was only observed for older developmental stages of M. longa while young stages of M. longa remained in deep waters both day and night. A mortality index indicated that non-migrating Calanus spp. suffered higher mortality than migrating M. longa. Key words: Calanus, Metridia longa, mortality, optics, vertical distribution Introduction along the vertical axis in the sea is to some extent due to the rapid attenuation of light in water (Jerlov The depth distribution of many copepods in cold- 1968). This sets up thermal stratification and limits temperate regions is characterized by a strong seasonality that is closely related to the annual cycle the depth range available for positive primary produc- in primary production (Vinogradov 1997).
    [Show full text]
  • Molecular Species Delimitation and Biogeography of Canadian Marine Planktonic Crustaceans
    Molecular Species Delimitation and Biogeography of Canadian Marine Planktonic Crustaceans by Robert George Young A Thesis presented to The University of Guelph In partial fulfilment of requirements for the degree of Doctor of Philosophy in Integrative Biology Guelph, Ontario, Canada © Robert George Young, March, 2016 ABSTRACT MOLECULAR SPECIES DELIMITATION AND BIOGEOGRAPHY OF CANADIAN MARINE PLANKTONIC CRUSTACEANS Robert George Young Advisors: University of Guelph, 2016 Dr. Sarah Adamowicz Dr. Cathryn Abbott Zooplankton are a major component of the marine environment in both diversity and biomass and are a crucial source of nutrients for organisms at higher trophic levels. Unfortunately, marine zooplankton biodiversity is not well known because of difficult morphological identifications and lack of taxonomic experts for many groups. In addition, the large taxonomic diversity present in plankton and low sampling coverage pose challenges in obtaining a better understanding of true zooplankton diversity. Molecular identification tools, like DNA barcoding, have been successfully used to identify marine planktonic specimens to a species. However, the behaviour of methods for specimen identification and species delimitation remain untested for taxonomically diverse and widely-distributed marine zooplanktonic groups. Using Canadian marine planktonic crustacean collections, I generated a multi-gene data set including COI-5P and 18S-V4 molecular markers of morphologically-identified Copepoda and Thecostraca (Multicrustacea: Hexanauplia) species. I used this data set to assess generalities in the genetic divergence patterns and to determine if a barcode gap exists separating interspecific and intraspecific molecular divergences, which can reliably delimit specimens into species. I then used this information to evaluate the North Pacific, Arctic, and North Atlantic biogeography of marine Calanoida (Hexanauplia: Copepoda) plankton.
    [Show full text]