Relation of Minimum Viable Population Size to Biology, Time Frame, and Objective

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.

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Natural extinction on islands

Philosophical Transactions of the Royal Society of London Series B Biological Sciences ◽

10.1098/rstb.1989.0099 ◽

1989 ◽

Vol 325 (1228) ◽

pp. 457-468 ◽

Cited By ~ 21

Keyword(s):

Population Size ◽

Point Of View ◽

Volterra Equations ◽

Food Chains ◽

Habitat Availability ◽

Ecological Changes ◽

Viable Population ◽

Minimum Viable Population Size ◽

Almost All ◽

Minimum Viable Population

Almost all recent extinction of species or subspecies on islands comes from human activities. On the other hand, in local populations there is much natural extinction and immigration, i.e. turnover, on small islands. Most of this turnover occurs in locally rare species, and attests to the phenomenon of minimum viable population size. The MacArthur-Wilson theory is based on this turnover which, from an ecological point of view, is generally trivial. More useful theories of minimum viable population size are being developed. Rarity is the precursor of extinction, and species can be rare in several ways. Models of these phenomena are still primitive, particularly those that relate habitat availability to population density. Models of interactive communities show phenomena that may be relevant to the understanding of extinction in the geological record. Lotka-Volterra equations indicate considerable sensitivity to invasions, sometimes producing a cascade of extinction. Chemostat equations show that the behaviour of food chains can change dramatically with small changes in parameters, suggesting that small environmental effects can sometimes cause large ecological changes, including extinctions, in interactive biotic communities.

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Minimum viable population size in the presence of catastrophes

Viable Populations for Conservation ◽

10.1017/cbo9780511623400.005 ◽

1987 ◽

pp. 59-68 ◽

Cited By ~ 42

Author(s):

Warren J. Ewens ◽

P. J. Brockwell ◽

J. M. Gani ◽

S. I. Resnick

Keyword(s):

Population Size ◽

Viable Population ◽

Minimum Viable Population Size ◽

Minimum Viable Population

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The Elusive Minimum Viable Population Size for White Sturgeon

Transactions of the American Fisheries Society ◽

10.1577/t09-069.1 ◽

2010 ◽

Vol 139 (5) ◽

pp. 1551-1565 ◽

Cited By ~ 7

Author(s):

Henriette I. Jager ◽

Ken B. Lepla ◽

Webb Van Winkle ◽

Brad W. James ◽

Steven O. McAdam

Keyword(s):

Population Size ◽

White Sturgeon ◽

Viable Population ◽

Minimum Viable Population Size ◽

Minimum Viable Population

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