Analysis on the fluctuation features of recruitment for juvenile Chinese sturgeon, Acipenser sinensis in the Yangtze River estuary

Abstract:

The Yangtze River estuary is an important self-adjusting and feeding ground for juvenile Chinese sturgeon in the migration to sea process. It is very helpful and meaningful for the protection of Chinese sturgeon via studying the long-term tendency for recruitment features of its juveniles in this area. In this study, we focused on the analysis of the fluctuation features of recruitment for juvenile Chinese sturgeon according to the survey data on the amount and biological characteristics of juvenile Chinese sturgeon during 2005-2013. The results showed: (1) the earliest occurrence time, the final departure time and time span of juvenile in the Yangtze River estuary were at the high level fluctuation; (2) recruitment of juvenile had general clear decrease and fluctuated strongly in different years; (3) Analysis of Variance (ANOVA) showed years had a significant effect on the mean of total length and body weight of juvenile (P<0.05); (4) the results of correlation analysis indicated that the mean of total length had a high association with the final departure time of juvenile (R=0.7196, P<0.05), which might be used to explain why the mean of total length in 2007 was significantly higher than the normal level.