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ISSN 0704-3716 CANADIAN TRANSLATION OF FISHERIES AND AQUATIC SCIENCES No. 4683 Anadromous arctic char in the Eidfjord watercourse by J.W. Jensen, and I. Steine Original Title: Sjoroye i Eidfjordvassdraget, Hardanger From: Fauna (Oslo) 33: 39-40, 1980 Translated by the Translation Bureau (AMG) Multilingual Services Division Department of the Secretary of State of Canada Department of Fisheries and Oceans Northwest Atlantic Fisheries Center St. John, Nfld. 1980 5 pages typescript I , • • DE4PARTMENT OF THE SECRETARY OF STATE SECRÉTARIAT D'ÉTAT TRANSLATION BUREAU BUREAU DES TRADUCTIONS MULTILINGUAL SERVICES DIVISION DES SERVICES CANADA DIVISION MULTILINGUES c Tres Yé› TRANSLATED FROM - TRADUCTION DE INTO - EN Norwegian English AUTHOR - AUTEUR John W. Jensen and Ivar Steine TITLE IN ENGLISH - TITRE ANGLAIS Anadromous arctic char in the Eidfjord watercourse. TITLE IN FOREIGN LANGUAGE (TRANSLITERATE FOREIGN CHARACTERS) TITRE EN LANGUE ÉTRANGÉRE (TRANSCRIRE EN CARACTÉRES ROMAINS) Sjei*e i Eidfjordvassdraget, Hardanger REFERENCE IN FOREIGN LANGUAGE (NAME OF BOOK OR PUBLICATION) IN FULL. TRANSLITERATE‘FOREIGN CHARACTERS. RÉFÉRENCE EN LANGUE ÉTRANGÉRE (NOM DU LIVRE OU PUBLICATION), AU COMPLET, TRANSCRIRE EN CARACTÉRES ROMAINS. FAUNA REFERENCE IN ENGLISH - RÉFÉRENCE EN ANGLAIS PUBLISHER - ÉDITEUR PAGE NUMBERS IN ORIGINAL DATE OF PUBLICATION NUMÉROS DES PAGES DANS Norwegian Zoological Journal Centre DATE DE PUBLICATION L'ORIGINAL 39-40 YEAR ISSUE NO. VOLUME PLACE OF PUBLICATION ANNÉE , NUMÉRO NUMBER OF TYPED PAGES LIEU DE PUBLICATION NOMBRE DE PAGES DACTYLOGRAPHIÉES Osl 1980 33 1 _5 REQUESTING DEPARTMENT DFO TRANSLATION BUREAU NO. MINISTÈRE -CLIENT NOTRE DOSSIER N 0 BRANCH OR DIVISION TRANSLATOR (INITIALS) Ale DIRECTION OU DIVISION SIPB TRADUCTEUR (INITIALES) PERSON REQUESTING in 17 DEMANDÉ PAR YOUR NUMBER ,, VOTRE DOSSIER N 0 DEC i98u DATE OF REQUEST 1( r-o DATE DE LA DEMANDE SOS-200-10-6 (RE V. 2/68) 7530-21-029-5333 Secretary Secrétariat "T` • of State d'État MULTILINGUAL SERVICES DIVISION — DIVISION DESSERVICESMULTILINGUES TRANSLATION BUREAU BUREAU DES TRADUCTIONS Client's No.—No du client Department — Ministère Division/Branch — Division/Direction City — Ville DFO SIPB Ottawa, Ont. Bureau No.-1\1 0 du bureau Language — Langue Translator (Initials) — Traducteur (Initiales) 2 — 1,9ei -7/ if .3-5-- g Norwegian AMG Nov. 22, 1980. Anadromous arctic char in the Eidfjord watercourse, Hardanger. by John W. Jensen and Ivar Steine FAUNA, vol 3, No 1, 1980 • published by the Norwegian Zoological Journal Centre, . . Oslo. .. ... - . .. '. - - . _. -. - .. - .. ., J.W. & Seine, 1. 1980. Anadromous arctic char in the Eidfjord river systent,Har- Jensen . . • - • — • . • ' - - danger: Fauna 33, 39-40.. ' . - . .The anadromous arctic char Salvelinus alpinus (L.) is a circumpolar -fish of the Arctic - Ocean. On the Norwegian Coast its distribution to the south has been litnifed -to Kongsnes Ri- - • . ver at 65°N. In Auzust 1970 -anadromous• arctic char were caught in the Eidtjorti river sv- . .• stern in the Hardanger Fjord, 470 km SSW of the fiver Ktingsnes. Many glacier-fed riVers of the Norwegian west coast have water cold enough to be colonised by the anadromous char. - A surface tetnperature of 13.5-14.0 0 in the cOnstal waters seems to limit the anadromous char in the south. J.W. Jensen. — Universitetet i "Frondheitn, Det koikelige Norske Videnska'oers Selskal-. Museet, N-7000 Trondheim. I. Steine, — Bergen Pedagogiske Hogskole, N-5000 Bergen. Arctic char (Salvelinus alpinus (L.)) is a northern circumpolar fish species. The anadromous form - which migrates in the sea - is found in the coastal waters of the Arctic Ocean and moves upriver in Alaska, Greenland, Iceland, Spitsbergen, Northern Norway and Siberia. It is common along the coast of Northern Norway and ascends in many locations together with salmon and sea (anadromous) trout. The Kongsnes river o in the bottom of Indre (Inner) Folla (6.5 North) is the southernmost river in Norway with sea trout (Fig. 1). Its occurence here is regular. In the river in Bindalen (dal=valley), 21 km further north, only six sea trout were found in a controlled catch of 1531 ascending fish during the period 1969-74 (Heggberget 1974). In August 1979 sea trout were caught in the Eidfjord watercourse in Hardanger. The new location is 470 km south-southwest of the Kongsnes river, as the crow flies. MNEDiTED TP.AMSIIIMON Fcl• SEC 5-25T (Rev. 6/78 1 2. (39) The Eidfjord watercourse consists of the Elo river which is two km long from the fjord to the Eidfjord lake. The Eidfjord lake is a 2 typical fjord lake; it has an area of 3.67 km and its greatest depth is 79 m. The lake has two large inflows: Anadromous fish can move • km in the Bjoreio and 2.5 km in the Veig. Both rivers are fed from mountain areas which are snowcovered until late in the summer; the Bjoreio is also fed from Hardangerà4kul(glacier). The water temperature in the rivers is between 110 and 14°C; it reaches 150- 16°C for short periods. There are small differences between the river/ the various sections in the watercourse but the glacial water keeps the temperature in the Bjoreio clown during the warmest summer periods. Six sea char were recorded during the period of August 9-11, 1979. These were typical glossy ascending fish, and weight analyses of scales and otoliths show typical sea growth. There is no inland char in the Eidfjord watercourse but there is salmon, sea trout and freshwater trout. Four sea char were caught in trial fishing with standard series of nets; one maskebitar4 (netbiter?) was hanging in a salmon net and one was caught with a rod near the end of the fish ladder in Veig (Fig. 1). Four checked sea char were 31-35 cm long and weighed 310-510 g. According to Nordeng (1961) and Mathisen & Berg (1968) this is the normal size of sea char in the Salang-and Vardnes rivers in Troms. Growth analyses of three of the char showed that they became smolt as three year olds with lengths of 15-22 cm. They had been in the sea for two seasons with a growth of 7-17 cm per year. Compared to conditions in the north this is a good growth. According to Nordeng (1968) it is normal that sea char in rivers in Northern Norway become smolt after three to seven years and are then 18- 26 cm long. All four checked char were males and were going to spawn the same falL, 3. (39-40) The Eidfjord watercourse is known for its good salmon and sea trout fishing. In connection with the present power development - with transmission from Bjoreio to Simadal (valley) in the north - the average annual catches in the watercourse are calculated as 6-7 tons of which 60% are salmon and 40% sea trout. Four tons are caught in nets in Eidfjord lake while three tons are caught by 'Mae (unknown* ) and rod in the rivers (Jensen & Steine 1979). The mesh width in salmon nets is 58 mm and sea char of the current size is not retained. In catches with trial series of bottom nets with mesh widths of 20-45 mm, the ratio between sea trout and sea char was 4:1. Net catches of sea trout in 1979 are calculated to be 1,000 and a further 1,000 smaller sea trout were probably caught in the rivers. At the end of the fishing season, on August 25, there is always a good residual population of sea trout. The number of sea trout of the size caught by the trial net series is assumed to be at least 1,000 in Eidfjord lake around August 10. If it is taken into consideration that char is normally more difficult to catch in nets than trout, it is likely that there were several hundred sea char in Eidfjord lake. It is thus not a question of single roaming individuals but a fairly large upriver migration. (*local term?) Char is characterized as a cold-stenothermal species. Its range toward the south depends naturally oritemperatures. Nordeng (1968) assumes that the sea char prefers riv:ers where the temperature does not exceed 12°C. The rivers in the Eidfjord watercourse will at times be warmer but th+emperature is levelled out in the Eidfjord lake which probably very rarely becomes warmer than 13°C. There are many watercourses in Vestlandet (Western Norway) wich satisfy such requirements because they are cooled by melt water from large snowfields and glaciers. The temperatures in the Sima river and the Osa watercourse, i.e. the watercourses adjacent to Eio in the north, were for example not above 10°C in 1974-75. The range of the sea (anadromous) char toward the south is not limited by temperature conditions in the rivers. 4. (40) Huitfeld-Kaas (1924) points out that the sea (anadromous) char at the Norwegian coast rarely moves to south of the 5°C isotherm for mean annual air temperature and it does not pass the 12° iso- therm for July-August. The barrier must, however, be based on sea temperatures*. Such conditions i_are present at this time, measured at four meters depth (Midttun 1975). It is apparent that the mean surface temperature for 10 day intervals . . Figur. I. Utbredelsen ;Iv foye (svart felt) 6g sjoroye (svart strek)i-Skandidavia. etter Huitfeld-Kiias (1924). in coastal waters at 65°North does Innfelt kart over Eigordvassdraget. The distribution of arctic chin. (black) and atiadro- not exceed 13.5-14.0 °C which must molts arctic char (black line) in Scandinavia. after Huitfeldt-Kaas (1924). Inserted tnap over the Eidliord be considered a barrier toward the riversreetn. south for sea (anadromous) char along * the coast of Norway.( and necessarily on maximum summer temperatures.) Important environmental requirements, such as temperature, feed animals and spawning conditions, appear to be satisfactory for the reproduction and establishment of sea (anadromous) char in the Eidfjord watercourse.