Juvenile northern rock sole (Lepidopsetta polyxystra) spatial distribution and abundance patterns in the eastern Bering Sea: spatially dependent production linked to temperature

Abstract

Abstract Annual spatial distribution and relative abundance of age-2 and age-3 northern rock sole (Lepidopsetta polyxystra) and summer bottom temperatures were analysed using data from eastern Bering Sea summer trawl surveys from 1982 through 2012. Previously observed differences in age-0 northern rock sole distribution persisted until age-2 and age-3. Latitudinal distributions of age-2 and age-3 fish were correlated most strongly with summer bottom temperatures 2 and 3 years prior to the survey year, during the time that the fish would have been age-0. Thus, temperature during the age-0 year may affect spatial distribution for the first few years of life. Distribution of age-2 and age-3 fish shifted northwards 2 years after the beginning of a warming trend from 1999 to 2003, and shifted southwards 2 years after a cooling trend from 2004 through 2010. Northerly distributions were correlated with high abundances. Density dependence was ruled out as a reason for northward shifts in distribution given a lack of correlation between latitudinal distributions and the annual abundances within the southern part of the distribution. We propose that the large northern nursery area produces large cohorts of northern rock sole, and that bottom temperatures in the age-0 year affect use of the northern nursery area.