The role of fish releasing in Caspian Salmon (Salmo trutta caspius) stock recruitment

Caspian Salmon is one of the valuable native species of the Caspian Sea, which hasthe most expensive meat in the market between the Caspian Sea species. Accordingto the fishing data afterward 1968, the fishing of Caspian Salmon dramaticallydecreased and some years not found in the fishing statistics of the Caspian Sea. Hencethe Shahid Beheshti Stock Recruitment center (SBSRC) has artificially propagatedthe Caspian Salmon since 1983 and has released the juvenile to their natural habitat.This study presented the production and releasing of the Caspian salmon in itsrecruitment program. Based on the fifth development program, on Islamic Republicof Iran, the releasing rate of 2010 and 2011 years shall be 600,000 and 750,000juveniles per year. The production of the Caspian Salmon juveniles in these yearswas more than the planned rate i.e. 850,000 and 860,000 pcs. During 2010 and 2011the broodstocks average weight was 3200 gr, and the number of eggs in 1 gram were11.38. Furthermore, the male to female ratio, fertilization rate, survival rate andhatching rate were 1 to 2, 98 %, 91 % and 92 % respectively. One and two summerjuveniles were released into the upstream and downstream areas of the tributaries ofthe Cheshmeh killeh and Sardabrood Rivers (Mazandaran-Iran). The findingsshowed that recruitment program of the Caspian Salmon was successful due toincreasing its fishing to about ten metric tonnes.

Keywords:

Cheshmeh killeh , Sardabrood , Fishing rate , Releasing , Smoltification