Genetic Isolation as a Result of Dam Construction: A Look at the Effects on Two Species of Darters
Kerstin Edberg and Philip Lienesch (Western Kentucky University, Bowling Green, KY)
Kerstin.edberg963@wku.edu, Philip.lienesch@wku.edu
The addition of dams into a riverine system causes a wide range of changes to the river as well
as to the fish assemblages of that river. Although there have been many studies documenting the
changes that occur to the fish assemblages in the impounded river, there have been fewer studies
examining the effects of the reservoir on the fish inhabiting the tributaries upstream of the
impoundment. One possible impact of the reservoir downstream is that it might act as a barrier to fish
migration from one stream to another.
To determine the extent to which reservoirs restrict migration, we looked for genetically isolate
in two species of darter from the Barren River Lake drainage basin. Twenty individuals of from each
species were collected from a total of 6 sites (3 streams directly connected to Barren River Lake, 3
streams directly connected to Barren River upstream of the reservoir). We are sequencing the DNA at 5
Microsatellite loci to determine the degree to which each population is isolated. If the reservoir is
restricting gene flow between populations, we predict that the populations in streams directly
connected to Barren River Lake will have lower allele diversity and heterozygosity. Current results will
be discussed along with implications for conservation of stream fishes.