Interannual variability in the early growth rate and size of the Antarctic fish Gobionotothen gibberifrons (Lönnberg)

• Published in: Antarctic Science
• Main Authors: North, A. W., White, M. G., Trathan, P. N.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1998
• Subjects: Geology; Ecology, Evolution, Behavior and Systematics; Oceanography; Antarctic; The Antarctic; Antarc*; Antarctic Science
• Online Access: http://dx.doi.org/10.1017/s0954102098000509; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102098000509

Gobionotothen gibberifrons <1 year old, of the 1977, 1980, 1981, 1985, 1986, 1990 and 1995 cohorts, were sampled using nets, in various periods during summer (December to February) at South Georgia. Growth in standard length (L s ) was estimated using the exponential model. Among the seven cohorts, average growth rate varied between 0.33–2.1% L s d −1 , and predicted L s for mid-January varied between 21.6–29.1 mm. Average growth rate was inversely related to mean date of sampling but was not significantly related to mean L s . Mean sea surface temperatures were available for the 1981–95 cohorts. Average growth rate and predicted L s for mid-January were both negatively conelated with mean December–January sea temperature, but were not significantly related to mean weekly sea surface temperature during the sampling periods. Greater average growth rate and greater L s in cooler summers may be partly due to a large-scale pattern of environmental variability, indicated by sea temperature, that governs the timing and magnitude of the production cycle and food availability.