Increase of inbreeding by stocking on wild population assessed by using individual-based life history model

Authored by T Oota, T Matsuishi

Date Published: 2005

DOI: 10.1111/j.1444-2906.2005.00932.x

Sponsors: No sponsors listed

Platforms: Fortran

Model Documentation: Other Narrative Mathematical description

Model Code URLs: Model code not found

Abstract

The genetic impact of stocking on natural populations was assessed by using individual-based life history models. Models were constructed that included density-dependent mortality at the early life stage, natural mortality, fishing mortality, and the number of released fish. These variables were varied by using random numbers. The focus was on the genetic impact of the number of released fish, the number of parent fish producing seedlings that were released, the sex ratio of the parent fish, fishing mortality, and the methods to select the parents of the seedlings. When brood stock size in the hatchery was five males and five females, the coefficient of inbreeding was about 27-fold as high as that in the case of 50 males and 50 females at the 50th generation. The coefficient increased about fivefold at the 50th generation, when the sex ratio of the parents changed from 50 males and 50 females to 10 males and 90 females. When parents were taken from wild populations at random, extreme fishing mortality reduced genetic diversity.

Tags

Size Traits Depression Hatchery Genetic risk