Water Resources Research Act Program

Details for Project ID 2016VT81B

Quantifying the consequences of water quality changes and habitat fragmentation on the genetic structure of aquatic organisms in the Lake Champlain basin

Institute: Vermont
Year Established: 2016 Start Date: 2016-03-01 End Date: 2017-07-31
Total Federal Funds: $10,013 Total Non-Federal Funds: $20,191

Principal Investigators: J Marsden, Peter Euclide

Abstract: As human populations expand, landscapes have become increasingly fragmented and water systems have become increasingly polluted. Habitat fragmentation negatively impacts natural processes such as genetic and species diversity, as well as ecosystem services including water quality, and thus is a major problem in conservation biology. Rivers have been repeatedly fragmented by dams, leading to a large body of research assessing the ecological and consequences of dams as barriers. Dams impact fish populations in many ways including destruction of habitat, impediment of movement, restriction of access to spawning sites, and loss of gene flow. The impact of fragmentation on lakes, however, is unknown, making the evaluation of lake fragmentation difficult to quantify. By concurrently evaluating the impact of habitat fragmentation across a range of systems, barrier types and fragmentation histories, it should be possible to determine how ecological impact of fragmentation varies with the type of barrier and system. This study will take advantage of a fragmented large lake system to test hypotheses about the impact of habitat fragmentation on fish populations. Since the early 1800s, construction of over 400 dams and ten major causeways in the Lake Champlain watershed has progressively divided the lake and its tributaries into a set of relatively isolated basins, providing a novel opportunity to study and compare the consequences of both river and whole-lake fragmentation on the population restructuring of fish species. Using molecular techniques, we will quantify the population genetic diversity of a species common to Lake Champlain and the surrounding tributaries. Two hypotheses will be tested: (1) habitat fragmentation in lakes has a lesser impact on genetic structure of fish populations than river fragmentation; and (2) man-made barriers present a similar obstacle for gene flow as natural, restrictive barriers like fall lines. This research will provide a quantitative assessment of population level effects of a historically fragmented landscape in a novel system and test hypotheses of species genetic sensitivity to fragmentation across a range of barriers.