Norske pigghåmerkinger 1958-61

Abstract

The Norwegian taggings of spiny dogfish are considered for the period 1958-61. The main results are that: a) there exists a regular migration between the British Isles (summer) and the Norwegian coastal waters (winter) and vice versa. There are some notable exceptions to this simple rule. b) the total yearly mortality rate in the stock of spiny dogfish in the waters concerned are calculated to be 25 %. This is not considered a disturbing figure with respect to the level of the stock. c) the investigations of the spiny dogfish in the Norwegian fjords seem to show that these most likely will have to be considered as strays from the main oceanic stock.