Retrospective analysis of growth of pink salmon Oncorhynchus gorbuscha from scales: Interannual variability

Abstract

Results of study of scale structure of 17 generations of pink salmon Oncorhynchus gorbuscha from the southeastern coast of Sakhalin (return in 1994–2001, 2005–2013) are presented. The absence of statistically significant correlation between the number of sclerites on scale and duration of staying of fish of separate generations in seawaters and body length was established. Values of intersclerite distances on scales positively correlate with fish length, which allows the use of this index for characteristic of pink salmon growth. At calculation of the rate of growth of fish, fry length at the moment of formation of central scale plate was introduced into the formula. It was found that interannual variation of scleritograms of the first annual zone of the growth of scales by its magnitude is comparable to regional. Specific features of growth of pink salmon to a greater extent are apparently determined by temperature conditions rather than the level of development of its food resources. Survival of generations of pink salmon during marine period of life positively correlates with the rate of growth of fingerlings, which can be used in prognostic purposes.