Известия ТИНРО (Dec 2014)
Dynamics of population parameters for pike <i>Esox lucius</i> L. (Esocidae) from the Anadyr River in the period of 1971-2010
Abstract
Samples of pike were collected by Lab. of Ichthyology, IBPN FEB RAS in the middle stream of the Anadyr River at Markovo in June-September of 1971-2010 and processed by standard methods; in total 2410 specimens were analyzed. The pike population changed significantly during the period of observation: the fish in catches became smaller and younger, growth rate decreased, and absolute and relative fecundity increased, mainly under impact of fishery, including industrial one that intensified in 1970-1980s. As the result, the pike abundance decreased in 1980s, and the first-spawning females and males became to prevail in its catches. Further decreasing of the abundance was able to promote a reduction of competition in the population. The population could be restored only after considerable decrease of fishing pressure, or banning of the species fishery, that would improve the feeding conditions. Recent lowering of the fishing pressure due to low stock causes partial recovery of the population accompanied by heightening of elder fish portion. Now the fish spawned several times prevail in the catches. However, the growth rate and females fecundity still differ from the values typical for the 1970s. Partial recovery of the pike population should be accounted in estimations of its predatory on other fishes in the Anadyr River, including commercial species.
Keywords
