Abstract

Stock assessments for Shovelnose Sturgeon have largely been limited to age and growth analyses using pectoral fin rays despite potential underestimation of age and lack of age validation. Fisheries stock assessments rely on accurate estimates of vital rates for effective fisheries management, within which fish age and lifespan are of primary importance. Age was estimated using pectoral fin rays and otolith sections, and bomb radiocarbon (C-14) dating was applied to otolith cores to determine lifespan and validate ages. Age reading of fin rays was straightforward, whereas most otolith thin sections provided two age-reading scenarios: lumping (primary increments) or splitting (finer increments) presumed annuli. While fin-ray estimates led to a maximum age of 14 years, otolith estimates led to maximum ages of 27 and 42 years. C-14 dating provided support for a combination of lumping early in life, to splitting in later years, and validation of a similar to 40-year lifespan. Age reading of otoliths was imprecise and resulted in similar to 40% of thin sections that were not age scoreable. However, scoreable otolith sections, coupled with C-14 dating, resulted in growth and lifespan information that are the most accurate to date for Shovelnose Sturgeon and can be used as a baseline toward stock assessment refinements.

Keywords

age validation; bomb radiocarbon dating; primitive fish; Scaphirhynchus platorynchus; Shovelnose Sturgeon; stock assessment

Published in

Fisheries Management and Ecology
2023, Volume: 30, number: 4, pages: 423-425
Publisher: WILEY

SLU Authors

• Andrews, Allen

  • Department of Aquatic Resources (SLU Aqua), Swedish University of Agricultural Sciences
    
  • University of Hawaii at Manoa

UKÄ Subject classification

Fish and Aquacultural Science


Publication identifier

DOI: https://doi.org/10.1111/fme.12633

Permanent link to this page (URI)

https://res.slu.se/id/publ/122416