Growth and condition in the Northwest Atlantic harp seal

Publisher Website
Google Scholar
Abstract
We analysed the relationship of length to age in a sample of 204 harp seals collected in 1976–1979 and of 437 animals collected in 1988–1992, by fitting asymptotic growth curves. The only significant variations were in asymptotic length, which for 1988–1992 was significantly larger for males (170.4 cm) than for females (165.3 cm). This sexual dimorphism was not significant in 1976–1979, because the fitted asymptotic length of females varied greatly from year to year, being large in the 1976–1979 samples. An index of body condition (total weight/length2.6) and a volume index constructed by regressing body weight on length × axillary girth squared indicated that harp seals collected in 1988–1992 were in poorer condition than animals collected during 1976–1979. Although this suggests a decline in available resources, the possibility of differences arising from sampling bias cannot be excluded.