The effect of fishing on the walleye pollock phenotype composition ...

• Main Authors: Izyumov, Yuri G., Gerasimov, Yuri V., Lapshin, Oleg M.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: ASC 2002 - Y - Theme session 2024
• Subjects: Fisheries and aquaculture; Pressures, impacts, conservation, and management; okhotsk sea
• Online Access: https://dx.doi.org/10.17895/ices.pub.25443589; https://ices-library.figshare.com/articles/conference_contribution/The_effect_of_fishing_on_the_walleye_pollock_phenotype_composition/25443589

No abstracts are to be cited without prior reference to the author.The study of phenotypic characteristics (vertebral column) gives us the valuable data for comprehension of population structure and genetic changes in fish. M. Iwata has studied in details the variability of vertebral column characters in 42 samples of the walleye pollock collected from the Pacific Ocean, the Okhotsk Sea and the Sea of Japan in 1968–1970. M. Iwata has found from 17 to 20 vertebrae in the abdominal section and from 29 to 33 in the caudal section of vertebral column in the walleye pollock specimens. We have col-lected more than 60 samples of walleye pollock from the trawls, Danish seines and set nets catches in 1999–2001 at different commercial fishing areas. It was found that after 30 years of intensive walleye fishing the average number of vertebrae in the caudal section significantly increased. In our samples we have never had a chance to see a specimen with 29 vertebrae in the abdominal section. We have supposed that the ...