Dams cause genetic homogenization in populations of fish that present homing behavior: Evidence from a demogenetic individual-based model
Authored by Daniel Ayllon, Rafael A Baggio, Sabrina B L Araujo, Walter A Boeger
Date Published: 2018
DOI: 10.1016/j.ecolmodel.2018.06.019
Sponsors:
Brazilian National Council for Scientific and Technological Development (CNPq)
Platforms:
Fortran
Model Documentation:
ODD
Flow charts
Mathematical description
Model Code URLs:
https://github.com/rbaggioufpr/homing
Abstract
Few studies have assessed the impact of dams on the distribution of the
genetic diversity of Neotropical fish species, and some of them suggest
that the genetic structure of fish metapopulations is not affected by
damming. However, the effects of dams on the genetic structure of
populations may hinge on the biological characteristics of the species,
such as homing behavior. Dams prevent some individuals from migrating
from their feeding area to their natal spawning area, constraining them
to reproduce in the tributaries that are closest to the barrier, and
which are already being used as breeding grounds by other
subpopulations. In these places, subpopulations may interbreed, thus
disrupting the overall genetic structure of the metapopulation. To test
this hypothesis, we developed a demogenetic Individual-Based Model that
simulates the impact of permeable and impermeable dams on the genetic
structure of homing populations, in both the long-term and the
short-term. Our results support that genetic homogenization occurs among
the subpopulations in the short-term, especially near the dam. The
impact of a dam on the genetic structure is also detectable in the
long-term (100 generations after the addition of the dam) when the dam
is permeable (symmetrical or asymmetrical). However, when the barrier is
not permeable, the genetic differentiation among the subpopulations is
reestablished in the long-term. Our results suggest that conservation
programs should be developed to avoid/mitigate genetic homogenization of
populations of fish that display homing behavior in the short-term, and
to reestablish the pre-dam genetic structure of these populations in the
long-term.
Tags
Population genetics
Atlantic salmon
Life-history
Brown trout
Habitat
fragmentation
Conservation genetics
Pseudoplatystoma-corruscans
White sturgeon
Dam
Trout salmo-trutta
Individual-based genetic model
Migratory
fish
Neotropical fish
Charr salvelinus-leucomaenis
Sao francisco river
Prochilodus-argenteus