Migrations of Spiny Dogfish, Squalus acanthias , and Recapture Success from Tagging in the Newfoundland Area, 1963-65

Abstract

From 2,378 spiny dogfish tagged on northwestern St. Pierre Bank and in Newfoundland coastal waters during 1963-65, there were 9.4% reported recaptures. Migrants from the St. Pierre Bank tagging were most abundant on the eastern part of the south coast of Newfoundland from June to December. Migrations to and from the east coast of Newfoundland were evident between July and December and on the west coast mainly between July and November. Some recaptures occurred south of the Laurentian Channel from the southern Gulf of St. Lawrence to Georges Bank. There was one transatlantic migration. Petersen discs yielded a higher percentage of returns than dangler tags and the return rate for larger dogfish was higher than for smaller dogfish. Recaptures occurred in depths from near-surface to 250 m but mainly from shallow depths. Many immature males and females and mature males overwinter in Newfoundland waters, and are killed by cold water in some winters. Lengths at tagging and recapture (10 years later) of a spiny dogfish provided additional evidence of the slow growth of this species.