Age Determination of the Yellow Irish Lord: Management Implications as a Result of New Estimates of Maximum Age

Abstract

AbstractThe yellow Irish lord Hemilepidotus jordani is an abundant, large sculpin found in the eastern Bering Sea and Aleutian Islands, where it is one of the most commonly caught sculpins. Interest in ecosystem‐based fisheries management has increased, prompting the need to collect life history information from nontarget or incidental bycatch species. Sagittal otoliths were used to age 776 yellow Irish lords sampled during 2005 and 2006 in summer bottom trawl surveys conducted by the Alaska Fisheries Science Center in the eastern Bering Sea and Aleutian Islands regions. Annuli viewed on otolith surfaces and thin sections were enumerated to arrive at estimates of age. Specimens ranged from age 1 to a maximum of age 28, more than doubling the previously published estimate of longevity for this species. Age estimates from both regions were used to calculate separate sex‐specific total mortality rates for yellow Irish lords based on catch‐curve analysis. These new age estimates have resulted in potential changes in yellow Irish lord harvest recommendations, demonstrating the importance of age and growth information to fisheries managers.Received January 18, 2011; accepted August 4, 2011