DOCSLIB.ORG

Antarctic Krill Fishery

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Antarctic Krill Fishery DERIS S.A – Pesca Chile- Antarctic Krill Fishery Picture from : fao.org PUBLIC COMMENT DRAFT REPORT JUNE 2018 Conformity Assessment Body: Bureau Veritas Certification Holding SAS Authors: Beatriz Roel Italo Campodonico José Ríos Contact: [email protected] Client: DERIS, S.A. DERIS S.A ANTARTIC KRILL FISHERY – Public Comment Draft Report page 1 Contents Contents .................................................................................................................................................. 2 Glossary ................................................................................................................................................... 4 1. Executive Summary ......................................................................................................................... 6 2. Authorship and Peer Reviewers ...................................................................................................... 8 3. Description of the Fishery ............................................................................................................. 10 3.1. Unit(s) of Assessment (UoA) and Scope of Certification Sought .......................................... 10 3.1.1 UoA and proposed Unit of Certification (UoC) ............................................................. 10 3.1.2 Total Allowable Catch (TAC) and UoC catch data: ........................................................ 14 3.2. Overview of the fishery ......................................................................................................... 15 3.2.1. History of the krill fishery .............................................................................................. 15 3.2.2. Fishing operation and gear configurations in use ......................................................... 20 3.2.3. Ownership, history and organisational structure of the assessed fleet ....................... 21 3.2.4. Assessed area: common fishing grounds, jurisdiction and user’s rights ...................... 21 3.3. Principle One: Target Species Background ........................................................................... 23 3.3.1. Background information ............................................................................................... 23 3.3.2. State of the stock .......................................................................................................... 29 3.4. Principle Two: Ecosystem Background ................................................................................. 37 3.4.1 Scotia Sea: context ........................................................................................................ 37 3.4.2 UoC catch composition: species assigment to MSC P2 categories ............................... 48 3.4.3 Primary species impacted by the UoC .......................................................................... 58 3.4.4 Secondary species impacted by the UoC ...................................................................... 59 3.4.5 ETP species impacted by the UoC ................................................................................. 59 3.5. Principle Three: Management System Background .............................................................. 61 3.5.1. Overarching framework ................................................................................................ 61 3.5.2. CCAMLR’s Principles and objectives ............................................................................. 62 3.5.3. CCAMLR’s Structure and Functioning .......................................................................... 62 3.5.4. Management of the Antarctic krill fishery .................................................................. 63 3.5.5. Chilean Law of Fisheries and Aquaculture (LFA) and legal provisions regarding the Antarctic krill ................................................................................................................................. 65 3.5.6. Chilean Fisheries Institutional Framework and specific requirements to the vessel ... 66 4 Evaluation Procedure .................................................................................................................... 69 4.1. Harmonised Fishery Assessment .......................................................................................... 69 Harmonisation process ................................................................................................................. 69 Cumulative impacts....................................................................................................................... 70 DERIS S.A ANTARTIC KRILL FISHERY – Public Comment Draft Report page 2 4.2. Previous assessments ........................................................................................................... 71 4.3. Assessment Methodologies .................................................................................................. 71 4.4. Evaluation Processes and Techniques .................................................................................. 71 4.4.1 Site Visit ......................................................................................................................... 71 4.4.2 Consultations ................................................................................................................ 72 4.4.3 Evaluation Techniques .................................................................................................. 73 4.4.4 Risk Based Framework .................................................................................................. 74 5 Traceability .................................................................................................................................... 74 5.1. Eligibility Date ....................................................................................................................... 74 5.2. Traceability within the Fishery .............................................................................................. 74 5.2.1 Processing and final product description ...................................................................... 74 5.3.1 Determination of risk associated to traceability factors prior to entering CoC ............ 74 5.3. Eligibility to Enter Further Chains of Custody ....................................................................... 77 5.4. Eligibility of Inseparable or Practicably Inseparable (IPI) stock(s) to Enter Further Chains of Custody ............................................................................................................................................. 78 6 Evaluation Results ......................................................................................................................... 79 6.1. Principle Level Scores ............................................................................................................ 79 6.2. Summary of PI Level Scores .................................................................................................. 79 6.3. Summary of Conditions ......................................................................................................... 81 6.4. Recommendations ................................................................................................................ 81 6.5. Determination, Formal Conclusion and Agreement ............................................................. 81 References ............................................................................................................................................ 82 Appendices ............................................................................................................................................ 90 Appendix 1 Scoring and Rationales ....................................................................................................... 90 Appendix 1.1 Performance Indicator Scores and Rationale ....................................................... 90 1.2 Appendix 1.3 Conditions ..................................................................................................... 198 Appendix 2 Peer Review Reports ........................................................................................................ 201 Appendix 3 Stakeholder submissions ................................................................................................. 219 Appendix 4 Surveillance Frequency .................................................................................................... 220 Appendix 5 Objections Process ........................................................................................................... 221 DERIS S.A ANTARTIC KRILL FISHERY – Public Comment Draft Report page 3 Glossary Below are presented the abbreviations and acronyms used in the report. The terms defined here do not contradict terms used in the MSC-MSCI vocabulary. Concepts and terms: B0 Unexploited biomass BLIM Precautionary reference point. SSB below B lim indicate increase risk of impairment of recruitment BMSY Spawning biomass (equilibrium) when fishing at FMSY BPA Precautionary reference point SSB below B PA indicate that action should be taken to recover the stock Btrigger Biomass level below which fishing mortality should be reduced BRP Biological Reference Points CAB Conformity Assessment Body (in the case of this particular assessment the CAB is Bureau Veritas Certification Holding SAS) CoC Chain of Custody CPUE Catch per Unit Effort CR (MSC) Certification
Load more

Recommended publications
  • Variable Expression of Myoglobin Among the Hemoglobinless Antarctic Icefishes (Channichthyidae͞oxygen Transport͞phylogenetics)
    Proc. Natl. Acad. Sci. USA Vol. 94, pp. 3420–3424, April 1997 Physiology Variable expression of myoglobin among the hemoglobinless Antarctic icefishes (Channichthyidaeyoxygen transportyphylogenetics) BRUCE D. SIDELL*†‡,MICHAEL E. VAYDA*†,DEENA J. SMALL†,THOMAS J. MOYLAN*, RICHARD L. LONDRAVILLE*§, MENG-LAN YUAN†¶,KENNETH J. RODNICK*i,ZOE A. EPPLEY*, AND LORI COSTELLO† *School of Marine Sciences and Department of Zoology, †Department of Biochemistry, Microbiology and Molecular Biology, University of Maine, Orono, ME 04469 Communicated by George N. Somero, Stanford University, Pacific Grove, CA, January 13, 1997 (received for review October 24, 1996) ABSTRACT The important intracellular oxygen-binding Icefishes exhibit several unique physiological features. Car- protein, myoglobin (Mb), is thought to be absent from oxi- diovascular adaptations to compensate for lack of hemoglobin dative muscle tissues of the family of hemoglobinless Antarctic in the circulation include lower blood viscosity, increased heart icefishes, Channichthyidae. Within this family of fishes, which size, greater cardiac output, and increased blood volume is endemic to the Southern Ocean surrounding Antarctica, compared with their red-blooded notothenioid relatives (2, there exist 15 known species and 11 genera. To date, we have 14–16). Combined with the high aqueous solubility of oxygen examined eight species of icefish (representing seven genera) at severely cold body temperature, these cardiovascular fea- using immunoblot analyses. Results indicate that Mb is tures are considered necessary to ensure that tissues obtain present in heart ventricles from five of these species of icefish. adequate amounts of oxygen carried in physical solution by the Mb is absent from heart auricle and oxidative skeletal muscle plasma.
    [Show full text]
  • Jan Jansen, Dipl.-Biol
    The spatial, temporal and structural distribution of Antarctic seafloor biodiversity by Jan Jansen, Dipl.-Biol. Under the supervision of Craig R. Johnson Nicole A. Hill Piers K. Dunstan and John McKinlay Submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Quantitative Antarctic Science Institute for Marine and Antarctic Studies (IMAS), University of Tasmania May 2019 In loving memory of my dad, whose passion for adventure, sport and all of nature’s life and diversity inspired so many kids, including me, whose positive and generous attitude touched so many people’s lives, and whose love for the ocean has carried over to me. The spatial, temporal and structural distribution of Antarctic seafloor biodiversity by Jan Jansen Abstract Biodiversity is nature’s most valuable resource. The Southern Ocean contains significant levels of marine biodiversity as a result of its isolated history and a combination of exceptional environmental conditions. However, little is known about the spatial and temporal distribution of biodiversity on the Antarctic continental shelf, hindering informed marine spatial planning, policy development underpinning regulation of human activity, and predicting the response of Antarctic marine ecosystems to environmental change. In this thesis, I provide detailed insight into the spatial and temporal distribution of Antarctic benthic macrofaunal and demersal fish biodiversity. Using data from the George V shelf region in East Antarctica, I address some of the main issues currently hindering understanding of the functioning of the Antarctic ecosystem and the distribution of biodiversity at the seafloor. The focus is on spatial biodiversity prediction with particular consideration given to previously unavailable environmental factors that are integral in determining where species are able to live, and the poor relationships often found between species distributions and other environmental factors.
    [Show full text]
  • A GUIDE to IDENTIFICATION of FISHES CAUGHT ALONG with the ANTARCTIC KRILL Author(S) 1) Iwami, T
    Document No. [ to be completed by the Secretariat ] WG-EMM-07/32 Date submitted [ to be completed by the Secretariat ] 1 July 2007 Language [ to be completed by the Secretariat ] Original: English Agenda Agenda Item No(s): 4.3 Title A GUIDE TO IDENTIFICATION OF FISHES CAUGHT ALONG WITH THE ANTARCTIC KRILL Author(s) 1) Iwami, T. and 2) M. Naganobu Affiliation(s) 1) Laboratory of Biology, Tokyo Kasei Gakuin University 2) National Research Institute of Far Seas Fisheries Published or accepted for publication elsewhere? Yes No x If published, give details ABSTRACT A field key to early life stages of Antarctic fish caught along with the Antarctic krill is produced. The key includes 8 families and 28 species mainly from the Atlantic sector of the Southern Ocean and uses distinguished characters which permit rapid field identification. In some cases, however, it is impossible to discriminate among species of the same family by remarkable characters. A species key is not shown for such resemble species and a brief summary of the main morphological features of species and genera is provided. SUMMARY OF FINDINGS AS RELATED TO NOMINATED AGENDA ITEMS Agenda Item Finding 4.3 We are producing a practical field key to juvenile fish caught along with the Antarctic Scientific krill. To our knowledge more than 40 species of fish have been found as by-catch. Observation However, the number of dominant fish species found in the krill catch never exceeds 20 species. An useful and practical identification key to these dominant species maybe facilitate the quantitative assessment of fish in the krill catch.
    [Show full text]
  • Fishes of the Eastern Ross Sea, Antarctica
    Polar Biol (2004) 27: 637–650 DOI 10.1007/s00300-004-0632-2 REVIEW Joseph Donnelly Æ Joseph J. Torres Tracey T. Sutton Æ Christina Simoniello Fishes of the eastern Ross Sea, Antarctica Received: 26 November 2003 / Revised: 16 April 2004 / Accepted: 20 April 2004 / Published online: 16 June 2004 Ó Springer-Verlag 2004 Abstract Antarctic fishes were sampled with 41 midwater in Antarctica is dominated by a few fish families and 6 benthic trawls during the 1999–2000 austral (Bathylagidae, Gonostomatidae, Myctophidae and summer in the eastern Ross Sea. The oceanic pelagic Paralepididae) with faunal diversity decreasing south assemblage (0–1,000 m) contained Electrona antarctica, from the Antarctic Polar Front to the continent (Ever- Gymnoscopelus opisthopterus, Bathylagus antarcticus, son 1984; Kock 1992; Kellermann 1996). South of the Cyclothone kobayashii and Notolepis coatsi. These were Polar Front, the majority of meso- and bathypelagic replaced over the shelf by notothenioids, primarily Ple- fishes have circum-Antarctic distributions (McGinnis uragramma antarcticum. Pelagic biomass was low and 1982; Gon and Heemstra 1990). Taken collectively, the concentrated below 500 m. The demersal assemblage fishes are significant contributors to the pelagic biomass was characteristic of East Antarctica and included seven and are important trophic elements, both as predators species each of Artedidraconidae, Bathydraconidae and and prey (Rowedder 1979; Hopkins and Torres 1989; Channichthyidae, ten species of Nototheniidae, and Lancraft et al. 1989, 1991; Duhamel 1998). Over the three species each of Rajidae and Zoarcidae. Common continental slope and shelf, notothenioids dominate the species were Trematomus eulepidotus (36.5%), T. scotti ichthyofauna (DeWitt 1970). Most members of this (32.0%), Prionodraco evansii (4.9%), T.
    [Show full text]
  • Wainwright-Et-Al.-2012.Pdf
    Copyedited by: ES MANUSCRIPT CATEGORY: Article Syst. Biol. 61(6):1001–1027, 2012 © The Author(s) 2012. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: [email protected] DOI:10.1093/sysbio/sys060 Advance Access publication on June 27, 2012 The Evolution of Pharyngognathy: A Phylogenetic and Functional Appraisal of the Pharyngeal Jaw Key Innovation in Labroid Fishes and Beyond ,∗ PETER C. WAINWRIGHT1 ,W.LEO SMITH2,SAMANTHA A. PRICE1,KEVIN L. TANG3,JOHN S. SPARKS4,LARA A. FERRY5, , KRISTEN L. KUHN6 7,RON I. EYTAN6, AND THOMAS J. NEAR6 1Department of Evolution and Ecology, University of California, One Shields Avenue, Davis, CA 95616; 2Department of Zoology, Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, IL 60605; 3Department of Biology, University of Michigan-Flint, Flint, MI 48502; 4Department of Ichthyology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024; 5Division of Mathematical and Natural Sciences, Arizona State University, Phoenix, AZ 85069; 6Department of Ecology and Evolution, Peabody Museum of Natural History, Yale University, New Haven, CT 06520; and 7USDA-ARS, Beneficial Insects Introduction Research Unit, 501 South Chapel Street, Newark, DE 19713, USA; ∗ Correspondence to be sent to: Department of Evolution & Ecology, University of California, One Shields Avenue, Davis, CA 95616, USA; E-mail: [email protected]. Received 22 September 2011; reviews returned 30 November 2011; accepted 22 June 2012 Associate Editor: Luke Harmon Abstract.—The perciform group Labroidei includes approximately 2600 species and comprises some of the most diverse and successful lineages of teleost fishes.
    [Show full text]
  • Mitochondrial DNA, Morphology, and the Phylogenetic Relationships of Antarctic Icefishes
    MOLECULAR PHYLOGENETICS AND EVOLUTION Molecular Phylogenetics and Evolution 28 (2003) 87–98 www.elsevier.com/locate/ympev Mitochondrial DNA, morphology, and the phylogenetic relationships of Antarctic icefishes (Notothenioidei: Channichthyidae) Thomas J. Near,a,* James J. Pesavento,b and Chi-Hing C. Chengb a Center for Population Biology, One Shields Avenue, University of California, Davis, CA 95616, USA b Department of Animal Biology, 515 Morrill Hall, University of Illinois, Urbana, IL 61801, USA Received 10 July 2002; revised 4 November 2002 Abstract The Channichthyidae is a lineage of 16 species in the Notothenioidei, a clade of fishes that dominate Antarctic near-shore marine ecosystems with respect to both diversity and biomass. Among four published studies investigating channichthyid phylogeny, no two have produced the same tree topology, and no published study has investigated the degree of phylogenetic incongruence be- tween existing molecular and morphological datasets. In this investigation we present an analysis of channichthyid phylogeny using complete gene sequences from two mitochondrial genes (ND2 and 16S) sampled from all recognized species in the clade. In addition, we have scored all 58 unique morphological characters used in three previous analyses of channichthyid phylogenetic relationships. Data partitions were analyzed separately to assess the amount of phylogenetic resolution provided by each dataset, and phylogenetic incongruence among data partitions was investigated using incongruence length difference (ILD) tests. We utilized a parsimony- based version of the Shimodaira–Hasegawa test to determine if alternative tree topologies are significantly different from trees resulting from maximum parsimony analysis of the combined partition dataset. Our results demonstrate that the greatest phylo- genetic resolution is achieved when all molecular and morphological data partitions are combined into a single maximum parsimony analysis.
    [Show full text]
  • Of RV Upolarsternu in 1998 Edited by Wolf E. Arntz And
    The Expedition ANTARKTIS W3(EASIZ 11) of RV uPolarsternuin 1998 Edited by Wolf E. Arntz and Julian Gutt with contributions of the participants Ber. Polarforsch. 301 (1999) ISSN 0176 - 5027 Contents 1 Page INTRODUCTION........................................................................................................... 1 Objectives of the Cruise ................................................................................................l Summary Review of Results .........................................................................................2 Itinerary .....................................................................................................................10 Meteorological Conditions .........................................................................................12 RESULTS ...................................................................................................................15 Benthic Resilience: Effect of Iceberg Scouring On Benthos and Fish .........................15 Study On Benthic Resilience of the Macro- and Megabenthos by Imaging Methods .............................................................................................17 Effects of Iceberg Scouring On the Fish Community and the Role of Trematomus spp as Predator on the Benthic Community in Early Successional Stages ...............22 Effect of Iceberg Scouring on the Infauna and other Macrobenthos ..........................26 Begin of a Long-Term Experiment of Benthic Colonisation and Succession On the High Antarctic
    [Show full text]
  • A Phylogenetic Perspective Ian A
    The Journal of Experimental Biology 206, 2595-2609 2595 © 2003 The Company of Biologists Ltd doi:10.1242/jeb.00474 Reduction in muscle fibre number during the adaptive radiation of notothenioid fishes: a phylogenetic perspective Ian A. Johnston1,*, Daniel A. Fernández1,†, Jorge Calvo2, Vera L. A. Vieira1, Anthony W. North3, Marguerite Abercromby1 and Theodore Garland, Jr4 1Gatty Marine Laboratory, Division of Environmental and Evolutionary Biology, School of Biology, University of St Andrews, St Andrews, Fife, KY16 8LB, Scotland, UK, 2Centro Austral de Investigaciones Cientificas (CADIC), Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) CC92, Ushuaia, 9410, Tierra del Fuego, Argentina, 3British Antarctic Survey, High Cross, Madingley Road, Cambridge, CB3 OET, UK and 4Department of Biology, University of California, Riverside, CA 92521, USA *Author for correspondence (e-mail: [email protected]) †Present address: Biology Department, Wesleyan University, Hall-Atwater and Shanklin Laboratories, Middletown, 06459, CT, USA Accepted 30 April 2003 Summary The fish fauna of the continental shelf of the Southern nodes of the maximum likelihood phylogenetic tree were Ocean is dominated by a single sub-order of Perciformes, consistent with a progressive reduction in fibre number the Notothenioidei, which have unusually large diameter during part of the notothenioid radiation, perhaps serving skeletal muscle fibres. We tested the hypothesis that in fast to reduce basal energy requirements to compensate for the myotomal muscle a high maximum fibre diameter (FDmax) additional energetic costs of antifreeze production. For was related to a reduction in the number of muscle fibres example, FNmax in Chaenocephalus aceratus (12·700±300, present at the end of the recruitment phase of growth.
    [Show full text]
  • Fitting Together the Evolutionary Puzzle Pieces of the Immunoglobulin T Gene from Antarctic Fishes
    Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 27 November 2020 doi:10.20944/preprints202011.0685.v1 Article Fitting together the evolutionary puzzle pieces of the Immunoglobulin T gene from Antarctic fishes Alessia Ametrano1,2 Marco Gerdol3, Maria Vitale1,4, Samuele Greco3, Umberto Oreste1, Maria Rosaria Coscia1,* 1 Institute of Biochemistry and Cell Biology - National Research Council of Italy, 80131 Naples, Italy; [email protected] (A.A.); [email protected] (U.O.); [email protected] (M.R.C.) 2 Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania Luigi Vanvitelli, 81100 Caserta, Italy; [email protected] (A.A.) 3 Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; [email protected] (M.G.); [email protected] (S.G.) 1,4 Department of Molecular Medicine and Medical biotechnology, University of Naples Federico II, 80131 Naples, Italy (Present address); [email protected] (M.V.) * Correspondence: [email protected]; Tel.: +0039 081 6132556 (M.R.C.) Abstract: Cryonotothenioidea is the main group of fishes that thrive in the extremely cold Antarctic environment, thanks to the acquisition of peculiar morphological, physiological and molecular adaptations. We have previously disclosed that IgM, the main immunoglobulin isotype in teleosts, display typical cold-adapted features. Recently, we have analyzed the gene encoding the heavy chain constant region (CH) of the IgT isotype from the Antarctic teleost Trematomus bernacchii (family Nototheniidae), characterized by the near-complete deletion of the CH2 domain. Here, we aimed to track the loss of the CH2 domain along notothenioid phylogeny and to identify its ancestral origins.
    [Show full text]
  • Champsocephalus Esox, Pike Icefish
    The IUCN Red List of Threatened Species™ ISSN 2307-8235 (online) IUCN 2020: T159100452A159404825 Scope(s): Global Language: English Champsocephalus esox, Pike Icefish Assessment by: Buratti, C., Díaz de Astarloa, J., Hüne, M., Irigoyen, A., Landaeta, M., Riestra, C. & Vieira, J.P. View on www.iucnredlist.org Citation: Buratti, C., Díaz de Astarloa, J., Hüne, M., Irigoyen, A., Landaeta, M., Riestra, C. & Vieira, J.P. 2020. Champsocephalus esox. The IUCN Red List of Threatened Species 2020: e.T159100452A159404825. https://dx.doi.org/10.2305/IUCN.UK.2020- 3.RLTS.T159100452A159404825.en Copyright: © 2020 International Union for Conservation of Nature and Natural Resources Reproduction of this publication for educational or other non-commercial purposes is authorized without prior written permission from the copyright holder provided the source is fully acknowledged. Reproduction of this publication for resale, reposting or other commercial purposes is prohibited without prior written permission from the copyright holder. For further details see Terms of Use. The IUCN Red List of Threatened Species™ is produced and managed by the IUCN Global Species Programme, the IUCN Species Survival Commission (SSC) and The IUCN Red List Partnership. The IUCN Red List Partners are: Arizona State University; BirdLife International; Botanic Gardens Conservation International; Conservation International; NatureServe; Royal Botanic Gardens, Kew; Sapienza University of Rome; Texas A&M University; and Zoological Society of London. If you see any errors or have any questions or suggestions on what is shown in this document, please provide us with feedback so that we can correct or extend the information provided. THE IUCN RED LIST OF THREATENED SPECIES™ Taxonomy Kingdom Phylum Class Order Family Animalia Chordata Actinopterygii Perciformes Channichthyidae Scientific Name: Champsocephalus esox (Günther, 1861) Synonym(s): • Chaenichthys esox Günther, 1861 Common Name(s): • English: Pike Icefish • Spanish; Castilian: Pez Hielo Taxonomic Source(s): Fricke, R., Eschmeyer, W.N.
    [Show full text]
  • Annex 6 Report of the Working Group on Ecosystem
    Annex 6 Report of the Working Group on Ecosystem Monitoring and Management (Bologna, Italy, 4 to 15 July 2016) Contents Page Opening of the meeting ...................................................................... 201 Adoption of the agenda and organisation of the meeting ............................... 201 The krill-centric ecosystem and issues related to management of the krill fishery ................................................................................ 202 Fishing activities ............................................................................ 202 Krill fishery notifications ............................................................... 203 Escape mortality ......................................................................... 204 Reporting interval for the continuous fishing system ................................ 204 Use of net monitoring cables ........................................................... 205 CPUE and fishery performance ........................................................ 206 Fishing season ........................................................................... 207 SG-ASAM report ........................................................................... 207 Scientific observation ...................................................................... 208 Observer coverage ...................................................................... 208 Krill biology, ecology and ecosystem interactions ...................................... 210 Krill .....................................................................................
    [Show full text]
  • Zur Polarforschung
    Berichte zur Polarforschung IM i V? The Expedition ANTARKTIS VI1/4 (Epos leg 3) and VII/5 of RV “Polarstern” in 1989 Edited by Wolf Arntz, Wolfgang Ernst and Irmtraut Hempel with contributions of the participants ALFRED-WEGENER-INSTITUT FÜR POLAR- UND MEERESFORSCHUNG Alfred Wegener Institute for Polar and Marine Research D-2850 Bremerhaven Bundesrepublik Deutschland - Federal Republic of Germany mgggggm -— __ _____ _ „ . -7 3 - 3.4 Micronekton of the Weddell Sea: Distribution and abundance U. Piatkowski. M. White, W. Dimmler Objectives Recent studies on the Zooplankton and micronekton distribution in the Weddell Sea have revealed three distinct communities which are closely related to bathymetric and hydrographic conditions (BOYSEN-ENNEN & PIATKOWSKI, 1988 among others). Although these communities have been described pre- viously, their transition zones or boundary regions are not well known. A fine- scale transect or grid of sampling stations is necessary to reveal the changes in the community composition in these transition areas. Accordingly, in paral­ lel with the hydrographic, benthic and ichthyological research during EPOS leg 3 two transects at right-angles to the coast line, one off Halley Bay, the other off Kapp Norvegia, were selected to investigate the transition zone between shelf and oceanic micronekton communities in more detail. The pelagic communities are subject to diel changes in composition, structure and abundance. In an ideal sampling Programme, this variable would be eliminated by collecting samples at the same time each day or by sampling at regulär intervals throughout each 24 hour cycle. It was impractical to under- take this type of approach during of EPOS leg 3 but as means of identifying the magnitude of diel variations occurring within the pelagic community a time Station was undertaken near Kapp Norvegia.
    [Show full text]