Minimum viable population size for lake sturgeon (Acipenser fulvescens) using an individual-based model of demographics and genetics

Authored by Daniel B Hayes, Amy M Schueller

Date Published: 2011

DOI: 10.1139/f10-129

Sponsors: No sponsors listed

Platforms: No platforms listed

Model Documentation: Other Narrative

Model Code URLs: Model code not found

Abstract

Population viability analysis is a useful tool to explore the relationship between extinction risk and population size, but often does not include genetic factors. Our objectives were to determine minimum viable population size (MVP) for lake sturgeon (Acipenser fulvescens) and examine how inbreeding depression may affect MVP. Our individual-based model incorporated inbreeding depression in two ways: individuals with inbreeding coefficients above a threshold experienced inbreeding depression (threshold), and individuals experienced inbreeding depression at a rate related to their inbreeding coefficient (gradual). Three mechanisms relating inbreeding to fitness were explored (young-of-the-year (YOY) viability, post-YOY viability, number of progeny). The criterion we used to determine MVP was a 5\% chance of extinction over 250 years. The estimated MVP without inbreeding effects was 80 individuals. For some scenarios incorporating inbreeding, MVP did not change, but for others, MVP was substantially higher, reaching values up to 1800. Results demonstrate that extinction risk and MVP can be influenced by both demographic stochasticity and inbreeding depression. This research should inform management by determining MVP and how inbreeding, which is expected to accrue in remnant populations because of generations of low abundance, may affect MVP.

Tags

Extinction risk Stochastic-model Conservation genetics Inbreeding depression Wild populations Viability analysis Great-lakes Capercaillie tetrao-urogallus Natural-population Atlantic forest