Freshwater Fish Introductions

My lab is applying sedimentary environmental DNA (eDNA) to reconstruct the sequence of historical fish introductions as well as their ecological impacts on aquatic communities:

a) Northern pike stocking in Alaskan lakes. Lakes on the Kenai Peninsula, Alaska were impacted by exotic northern pike introductions, which were subsequently chemically eradicated with rotenone. As part of lake restoration efforts, the lakes then had their fish communities intentionally reset with different ecotypes of native three-spine stickleback (see below, whole lake studies). Sediment cores were retrieved from a subset of these lakes to measure the responses of plankton communities to the removal of pike and re-introduction of stickleback as well as forest fire dynamics, climate change and other possible species invasions using a combination of zooplankton subfossil remains, sedimentary chlorophyll a + its diagenetic products, and sedimentary eDNA. PhD candidate Z. Rabinovich (McGill), I. Gregory-Eaves is the principal supervisor, cosupervisor: Derry; Collaborator: J. Smol (Queen’s).

b) Brook trout stocking in Parc national Témiscouata (Québec). In Témiscouata Park lakes, another fish species, threespine stickleback, has been identified with unique phenotypic adaptations and as a species of conservation concern in face of historical anthropogenic stocking of brook trout. We are applying sedimentary eDNA to explore correlations between changes in abundance of stickleback over time in relation to stocking of a predatory fish, brook trout, and other stocked fish competing for resources, redbelly dace and creek chub. MSc candidate H. Pfister (UQAM). Co-supervisors: Andrew Hendry and Grant Haines, partnership with Québec Sépaq; Collaborator: J Smol, Queen’s.