RESPONSES OF RELATIVE ABUNDANCE OF DOMINANTS IN FISH COMMUNITIES TO THE SEA OF OKHOTSK CLIMATE VARIABILITY
Abstract
The dynamics of the relative abundance of dominant species and the dynamics of the factor scores of all the rest of the species of nekton in the upper and entire epipelagic layers is studied by years, according to the data of the summer and autumnal comprehensive ecosystem studies of the Sea of Okhotsk (1984–2006). Time-spatial differences in the discovered agreements of the fluctuations of relative abundance of species, abstractly have been the factors of multivariate analysis, with the dynamics of the number of sun spots. Climate Indices of the Northern Pacific, hydro- and atmospheric principal components and EOFs of the Sea of Okhotsk are discussed. Perceptible deviation of biotic factor scores noted in 1990, 1991 and 1997, 1998. Strong (|R| ≥ 0.8) and statistically significant (p < 0.05) correlations between changes of relative abundance of species and abiotic factors of environment with a time-lag up to 6 years are extremely rare and most of them appeared as a result of analyzing data samples with a big proportion of common null values. A great role of casual variations is assumed. Attempts to use moving average and autocorrelation functions during time series analysis in most cases fail because there are a lot of gaps in the short time series (less than 25 years) we have. Even the successful one is useless yet because of a big confidence interval which is greater than the observed variability.