Snapshot: CDFW and Moss Landing Student Work Together to Estimate California Halibut Age-at-Length

halibut otolith section
12-year-old California halibut otolith section
CDFW photo by T. Tanaka

This summer, staff from CDFW’s Northern and Central California Finfish Research and Management Project assisted Moss Landing Marine Laboratories graduate student Cheryl Barnes in the preparation and age determination of 452 California halibut otoliths (ear bones). The age determinations from this collaborative work provide valuable information to fishery managers by greatly expanding the Project’s long-term, ongoing age-length database for California halibut.

A strong showing of 7- to 9-year-old halibut was evidence of better than average survival and settlement of young halibut in 2004 and 2005. The halibut, mostly of legal size, were collected from central California ocean waters during the summers of 2012 and 2013 as part of Barnes’ master’s thesis work. Each otolith was mounted in epoxy resin, cut into thin sections using a diamond saw, and examined under a microscope using high magnification to determine ages. For more information about California halibut research please visit CDFW’s California Halibut Studies webpage.

post by Paul Reilly, CDFW Senior Environmental Scientist Supervisor