Relation between stock size and catch data of Atlantic salmon (Salmo salar) and Arctic charr (Salvelinus alpinus)

• Main Authors: Ingi Rúnar Jónsson 1965-, Þórólfur Antonsson 1957-, Sigurður Guðjónsson 1957-
• Other Authors: Landbúnaðarháskóli Íslands
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2008
• Subjects: Laxveiðar; Silungsveiðar; Arctic; Gerðar; Vesturdalsá; Arctic charr; Atlantic salmon; Salmo salar; Salvelinus alpinus
• Online Access: http://hdl.handle.net/1946/20038

Reliable catch statistics are one of the most important factors in fisheries research and in managing exploitation of fish stocks. For more than 30 years catches in Icelandic rivers have been reported in logbooks. In these logbooks, fish species, fish size, fishing pool, date, etc. were registered. It has been suggested that the total number of salmonids caught annually reflects the total population in each river. Fishing effort, i.e. the number of rods per day, has been regulated by authorities, as well as the length of the fishing season. However some minor changes have developed gradually over time. In the ‘90s new fish counters were introduced, making possible to evaluate the relation between run and catch. The counter gives the number of migrating fish and their size. The run was divided into one-sea-winter salmon (1SW), two-sea-winter salmon (2SW) and charr, by size. The relationship between the total stock size and the number of fish caught for 1SW salmon, 2SW salmon and charr in the Vesturdalsá and Blanda rivers was then examined. This relationship was highly significant in all cases, except for charr in the River Blanda. The results showed that the salmon catch statistics in the Vesturdalsá and Blanda rivers are good indicators of the size of the salmon run. This relationship was not as strong for the charr. Furthermore, the size of the population of salmon and charr showed similar fluctuations. Áreiðanleg skráning á veiði er ein undirstaða rannsókna á fiskstofnum og nýtingu þeirra. Oft eru þetta einu gögnin um fiskistofn, en stærð veiðistofnsins er óþekkt. Laxveiði hefur verið skráð í þar til gerðar veiðibækur í flestum ám landsins um 30 ára skeið og sumum ám töluvert lengur. Þar koma fram upplýsingar um lengd, þyngd, kyn, dagsetningu veiðinnar og veiðistaður. Silungsveiði hefur einnig verið skráð en ekki eins vel og laxveiðin. Talið hefur verið að skráð veiði hvert ár endurspegli gönguna bæði í fjölda og samsetningu (t.d. smálax/stórlax). Erfitt hefur verið að sannreyna þetta. Sóknin, þ.e. fjöldi ...