A1 Refereed original research article in a scientific journal
Changes in age and maturity of anadromous whitefish (Coregonus lavaretus) in the northern Baltic Sea from 1998 to 2014
Authors: Veneranta Lari, Kallio-Nyberg Irma, Saloniemi Irma, Jokikokko Erkki
Publisher: EDP SCIENCES S A
Publication year: 2021
Journal: Aquatic Living Resources
Journal acronym: AQUAT LIVING RESOUR
Article number: ARTN 9
Volume: 34
Number of pages: 11
ISSN: 0990-7440
eISSN: 1765-2952
DOI: https://doi.org/10.1051/alr/2021007
Abstract
The maturation of anadromous whitefish (Coregonus lavaretus) was analysed from samples taken from commercial coastal fishing in 1998-2014 in the Gulf of Bothnia. Whitefish matured at a younger age from year to year. The proportion of older (5-12 sea years) mature males decreased from 79% to 39% in the northern Gulf of Bothnia (66 degrees N-64 degrees N) and from 76% to 14% in southern (64 degrees N-60 degrees 30'N) during the study period. At the same time, the proportion of young males (2-4 sea years) increased. Whitefish matured younger: the proportion of mature fish at age four increased in both the north and south among females (13% -> 98%; 6% -> 85%) and males (68% -> 99%; 29% -> 89%). The catch length of four-year-old fish increased during the study period in both sexes. In contrast, the length of six-year-old females decreased from year to year. Sea surface temperatures increased during the study period, and were possibly associated with a decrease in the age of maturation and faster growth.
The maturation of anadromous whitefish (Coregonus lavaretus) was analysed from samples taken from commercial coastal fishing in 1998-2014 in the Gulf of Bothnia. Whitefish matured at a younger age from year to year. The proportion of older (5-12 sea years) mature males decreased from 79% to 39% in the northern Gulf of Bothnia (66 degrees N-64 degrees N) and from 76% to 14% in southern (64 degrees N-60 degrees 30'N) during the study period. At the same time, the proportion of young males (2-4 sea years) increased. Whitefish matured younger: the proportion of mature fish at age four increased in both the north and south among females (13% -> 98%; 6% -> 85%) and males (68% -> 99%; 29% -> 89%). The catch length of four-year-old fish increased during the study period in both sexes. In contrast, the length of six-year-old females decreased from year to year. Sea surface temperatures increased during the study period, and were possibly associated with a decrease in the age of maturation and faster growth.
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