Cohort Dynamics of Walleye Pollock in Shelikof Strait, Gulf of Alaska, during the Egg and Larval Periods
- 1 May 1989
- journal article
- research article
- Published by Oxford University Press (OUP) in Transactions of the American Fisheries Society
- Vol. 118 (3) , 264-273
- https://doi.org/10.1577/1548-8659(1989)118<0264:cdowpi>2.3.co;2
Abstract
We estimated population parameters for early life stages of walleye pollock Theragra chalcogramma from 1981 ichthyoplankton samples collected in Shelikof Strait, Alaska. Instantaneous mortality of eggs was high before peak spawning (about 0.40/d) and decreased to about 0.10/d toward the end of the spawning season. This change can be explained in part by decreasing numbers of cannibalistic juvenile and adult walleye pollock in the spawning area. The mortality of larvae 4–10-mm in standard length was generally less (about 0.09/d) than that of eggs. Total egg production estimates from egg sampling and hydroacoustic surveys of adults were 6.62 × 1014 and 7.17 × 1014, respectively. Egg surveys resulted in good agreement with other methods for estimating walleye pollock biomass. Total spawner biomass estimated by the egg production method was 3.1 million tonnes, which was not substantially different from the hydroacoustic (3.4 million tonnes) or cohort analysis (2.4 million tonnes) estimates. Simulated...This publication has 1 reference indexed in Scilit:
- Why Do Fish Populations Vary?Published by Springer Nature ,1984