McGill University
Candidat M.Sc.
superviseur(e): Irene Gregory-Eaves
Alison Derry
Début: 2023-09-01
Fin: 2025-09-01

Projet

Response of zooplankton communities following reintroduction of native fish into northern lakes: A paleolimnological study of replicated whole lake experiments
Northern ecosystems are experiencing climate change at an accelerated rate compared to temperate systems. However, long-term ecosystem-level experiments in this region are quite rare. The Alaska eco-evo stickleback project has leveraged the “clean slate” provided by Department of Fish and Game who treated 8 lakes with rotenone to remove non-native invasive pike. Subsequently, an international team introduced benthic ecotypes (evolved in shallow lakes) or limnetic ecotypes (evolved in deep lakes) of native stickleback (Gasterosteus aculeatus) to quantify how they adapted to their new habitats. In this study, we will retrieve sediment cores from a subset of these experimental 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. To assess community shifts, we will study zooplankton subfossil remains in the sediment core as this organism serves as strong biological indicators of ecosystem change. In deeper waters, sediment is deposited chronologically, with each layer representing a snapshot in the lake’s history. We will extract lake sediment cores from six different lakes: two shallow lakes where limnetic stickleback ecotypes were introduced, two deep lakes with the limnetic ecotypes and two reference lakes (one deep and one shallow). We expect to see pronounced shifts in the lake communities, especially in response to the limnetic stickleback. These findings will help predict the responses of zooplankton communities in northern ecosystems while also advancing the study of eco-evolutionary conservation efforts.

Mots-clés

Paleolimnology, zooplankton, Conservation, Northern Ecosystems, lakes