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15e» 0-7041-31/& t_Canadian Translation of Fisheries and Aquatic Sciences No. 5067 Coastal seal investigations: cruise reports LIBRARY «. FISHER TES AND .00EA1. BIBLIOTI IÈQUE A. Bjorge, B. Bergflodt, and K.A. Fagerheim PikIIES ET OCÉANS Original title: Kystselundersokelser In: Fiskeridirektoratets havforskningsinstitutt, Bergen, Norway, 46 p., 1980 Original language: Norwegian Available from: Canada Institute for Scientific and Technical Information National Research Council Ottawa, Ontario, Canada R1A 0S2 1984 79 typescript pages Secretary Secrétariat of State d'État MULTILINGUAL SERVICES DIVISION — DIVISION DES SERVICES MULTILINGUES TRANSLATION BUREAU BUREAU DES TRADUCTIONS LIBRARY IDENTIFICATION — FICHE SIGNALÉTIQUE cr F 4- 7 Translated from - Traduction de Into - En Norwegian English Author - Auteur A. Bjorge, B. Bergflbdt and K.A. Fagerheim Title in English or French - Titre anglais ou français Coastal Seal Investigations Title in foreign language (Transliterate foreign characters) Titre en langue étrangère (Transcrire en caractères romains) Kystselundersokelser Reference in foreign language (Name of book or publication) in full, transliterate foreign characters. Référence en langue étrangère (Nom du livre ou publication), au complet, transcrire en caractères romains. Toktrapporter Reference in English or French - Référence en anglais ou français Cruise Reports Publisher - Editeur Page Numbers in original DATE OF PUBLICATION Numéros des pages dans DATE DE PUBLICATION l'original Institute of Marine Research Issue No. 1 - 46 Year Volume Place of Publication Année Numéro Number of typed pages Lieu de publication Nombre de pages dactylographiées Bergen, Norway 1980 79 Requesting Department Fo Translation Bureau No. /G‘. 5 -7 -7 -7 Ministère-Client Notre dossier no Branch or Division / Translation (Initials) Direction ou Division Traducteur (Initiales) Person requesting A 1: Demandé par Your Number Votre dossier no Date of Request o8- o 2 _ Date de la demande Canaa' SEC 5-111 (Rey. 82/11) ,Secretary Secrétariat F.* of State d'État MULTILINGUAL SERVICES DIVISION — DIVISION DES SERVICES MULTILINGUES TRANSLATION BUREAU BUREAU DES TRADUCTIONS Client's No.—No du client Department — Ministère Division/Branch — Division/Direction City — Ville pro DPC Bureau No.—No du bureau Language — Langue Translator (Initials) — Traducteur (Initiales) . /07-5- 3777 Alorzoe._g_ii-L,_ /1111 Coastal Seal Investigations Cruise Reports A. Bjorge, B. Bergflodt and K. — A. Fagerheim Institute of Marine Research, Directorate of Fisheries Bergen. SEC 5-25 (Rev. 82/11) Canadâ 2 . Preface The Institute of Marine Research has since 1975 carried out field studies on coastal seals (grey seal and harbour seal) between Stadt and Lofoten. The field work was carried out during one or two short cruises yearly from 1975 to 1980. The(collectedImaterial\from the cruises is now being worked up and reports on the coastal seal biology, stock size and their relationship to the fisheries will become available in the new year 1981. Due to considerable interest in our field observations, we have found it convenient to collect the cruise reports in one volume. The field trips from 1975- 77 have been published earlier, but the 1977-80 reports are only type- written and originally intended for internal use. Terje Benjaminsen led the field work up to 1977 and Torger Ôrritslan d has been the project leader all along. The cruise reports have different authors) and it is indicated in the report who participated in the work. Everyone is hereby thanked for their contribution. Arne Bjbrge Bjorn Bergflodt Kjell-Arne Fagerheim s 3. _ t.F TABLE OF CONTENTS Page Counting of grey seals along the Norwegian coast from Halten-Froam to Bode) and studies on the parasite infection in fish at Vega. 1. 5. Grey Seal investigations on the Norwegian Coast from Lofoten to Froya, September - November 1976. 8. 20. Harbour Sealand Grey Seal_investigations on the Norwegian coast from Nordmbre to Setrhelgeland in 1977. 19. 43. Harbour Seal investigations on the More and Trondelag coasts in 1978. 24. 54. Grey seal investigations on the coast between Statt and Bronnàysund in 1979. 32. 62. Grey seal investigations in the whelping period in the fall of 1979. 37. 68. Harbour seal and grey seal investigations in the summer of 1980. 42. 74. 4 "Jaktinteressen synes fremdeles à vmre liten hva haverten angâr" "The interest in hunting still seems to be low with respect to the grey seal." Reprint of "Reports" no. 1-1976. Counting of Grey Seals on the Norwegian Coast from .p. 1 Halten-Froan to Bod8 and Studies on the Parasite Infection in Fish at Vega. by Terje Benjaminsen, Bjorn Bergfledt and Ingvar Huse, Institute of Marine Research. Introduction In the early 1960Is, the number of whelping grey seal females (Halichoerus grypus) on the coast between Halten- Froan and Bode was estimated to be about 600 animals (Oynes, 1964). At that time the grey seal was protected in Sor- Trbndelag county (Royal Resolution of April 24, 1953) and there was little interest in hunting this seal species. In 1973 all seal species were totally protected in Southern Norway from the Swedish border up to and including Sogn and Fjordane County, and protected from May 1 to November 30 further north along the Norwegian coast (Royal Res. of April 13, 1973). In this area there are also two nature reserves > Bliksvaer and Ytre Vikna where seals are totally protected within two kilometres from the outer borders of the reserve. (Royal Res. of Dec. 4, 1970 and Nov. 16, 1973). "The hunting interest" still seems to be low with respect to the grey seal. As pointed out by dynes' (1964) the skins of the grey seal are low in demand and the value of the pelt is low compared with our other coastal seal, the harbour seal (Phoca vitulina). 0 • Through the Norwegian Fishermen's Organizatione it was reported by local fishermen's organizations in 1974 and 1975 that the seal population in Southern Helgeland had increased in number and that this had led to high exploitation of fisheries resources, damage to fishing gear and spread of parasite infection of fish in the area. From earlier studies in Great Britain (Young, 1972) and Canada (Scôtt and Fisher, 19 -%) it is known that the grey seal is the most important host animal for the parasitic roundworm (nematode) Phocanema decipiens (=Terranova decipiens) which spilds part of the larval stage in fish. It is this round- worm larva that can be found as "kveis" ("cyst") in the flesh of the fish (Berland, 1973). The problem had been identified before, and as early as in the summer of 1974, the Institute of Marine Research first attempted to count grey seals and to study the nematode infection of fish near Vega, (Benjaminsen et al., 1975). It was then found that the nematode infection was so high in this area that the fish from some fishing grounds could not be sold, and that some fishing grounds and fishing methods had been given up. About 50% of 30 cod and more than 90% of 20 cusk that were studied at a fish buying station at Kirki;y in Vega were infected by nematodes in the flesh. Poor weather conditions hindered the counting of seals, but it was confirmed that the seal population seemed to be increasing at Vega. New investigations were carried out at Vega between July 7 and 9, 1975, and in the fall of 1975 funds were made 7. available by the Fishing Industry Research Fund for more extensive studies of grey seals in the whelping period. The investigations were chiefly aimed at mapping the grey seal pupping areas on the coast from Froan to Bod6 and to find out if the pups could be counted from an airplane. In some localities the aerial counting was to be confirmed and tagging and collection of material for parasite studies carried out. These activities - are described in the following together with the counts and parasite studies carried out at Vega in July 1975. Seal Counting at Vega in JulY 1975 Counting of seals was carried out from a motor boat in the area southwest to north of Vega in the period July 7- 9. The weather was good with good visibility. Most of the animals observed were grey seals, a total of 33 animals. Only 3 harbour seals were seen. Two of the seals were too far away to be identified as to species. Most of the grey seal observations were made in Fuglevaer west of Vega and off Bremstein. It is probable that some of the grey seals that pup in the area in the fall had migrated in search of food so that the count does not give a correct picture of the population in the area. Seal Counting from Froan to Bode) in October 1975 Grey seals pup on the outer skerries and small islands along the coast, chiefly from Mbre to Nordland in the period 8. September - November. The pups are born with a long-haired white fur which they lose after 2 - 3 weeks. After moulting the pups have a short-haired grey pelt. The first weeks after birth the pups spend all their time ashore. By counting in the middle of the pupping period, a minimum estimate of the number of pups born can be made. The sexually mature females have a pup each year and comprise about one fourth of the population of one-year old and older animals. The total population can be estimated by multiplying the number of pups by four. Using Brônnbysund as a base, most of the knomm pupping areas for grey seal along the coast from Froan to Bodo were investigated from the air between October 8 and 16. Total p. 2 flying time was 12 hours and 30 minutes. Cessna seaplane was leased from Norwing. The track covered is shomm in Fig.