Capelin (Mallotus villosus) fecundity in post-1990s coastal Newfoundland

In the 1990s, a cold water event was associated with drastic changes in the biology of Newfoundland capelin (Mallotus villosus), the key forage fish in the north Atlantic. In contrast to studies conducted prior to the 1990s, we report a lower maximum potential fecundity (7,616-42,880) and a weak relationship between fecundity and body size based on fecundity of 218 female capelin (12.3-16.9 cm) collected within two coastal regions of Newfoundland in 2008 and 2009. Further, using forward stepwise multiple regression and hierarchical partitioning, we conclude that life history traits (mass, somatic mass and egg size) and condition indices (Fulton's K, Hepatosomatic Index and Gonadosomatic Index) are not appropriate proxies for fecundity of capelin in our study area. Hierarchical partitioning revealed that egg size and condition indices suppress the variance in fecundity explained by other factors. Based on the insight it provides into the influence of traits on fecundity, we suggest that hierarchical partitioning is a powerful analysis technique that could be used in further investigations.