Migration of pre-spawning capelin (Mallotus villosus) on the northern Grand Bank

Association between average temperature ( degree C) from 0-75 m and the size distribution of capelin (Mallotus villosus) on the northern Grand Bank () 46 degree N 52 degree 45'W-49 degree 10'N 49 degree 30'W) were explored, using information from research vessel surveys conducted during May from 1985 to 1992. Immature capelin were generally distribution in the northern part of the survey area while mature capelin were distributed in the south. Mature capelin are believed to migrate to the southern area in the spring, prior to onshore migration. Distribution of mature capelin was not associated with temperature on relatively small spatial () 2000 km super(2)) and temporal (within years) scales, but was on larger spatial () 90,000 km super(2)) and temporal (among years) scales. Assuming a link between maturation rate and migration, we propose that temperature is not used as a proximate cue during capelin migration, but that seasonal temperatures moderate offshore capelin migration patterns through regulating growth, maturation, and food abundance and distribution. Capelin are growing and migrating on a biological cycle but research surveys are conducted on a chronological cycle. Consequently, biomass acoustic estimates may be underestimated in cold years if spring migration into the survey area is delayed.