Trends in Sedimentary Diatom Assemblages Metal(loid) Concentrations Over the Last ~200 Years in Lake Temagami in Response to Multiple Environmental Stressors

In this thesis, I reconstruct environmental changes in Lake Temagami over the past ~200 years using diatoms, sedimentary metal(loid)s, and chlorophyll-a concentrations. Small centric diatoms, such as Discostella stelligera (Cleve & Grunow) and Cyclotella spp., are examined as indicators of thermal stratification and climate-driven changes in lake dynamics. Through the analysis of sedimentary diatom assemblages from three strategically selected cores, close to the town (Core 1), at the initial widening of the northeast arm (Core 2), and within the central hub of the lake (Core 3), I investigated the influence of temperature, wind speed, and metal(loid) concentrations on the diatom community composition. Statistical analyses revealed specific associations of diatom abundance with environmental stressors throughout the three cores, reflecting local ecological responses. The presence of Discostella stelligera, a diatom indicative of stable, thermally stratified waters particularly in Core 3, follows increasing temperature and decreased wind speeds.

Name thesis:degree_name

Master of Science (M.Sc.)

Level thesis:degree_level

Master's

Discipline thesis:degree_discipline

FLAG

Grantor dc:publisher

Carleton University

Year dc:date.issued

2026

Author dc:creator

• Atienza, Jose Roginal Gabriel

Statement dc:rights

• Copyright © 2026 the author(s). Theses may be used for non-commercial research, educational, or related academic purposes only. Such uses include personal study, distribution to students, research and scholarship. Theses may only be shared by linking to the Carleton University Institutional Repository and no part may be copied without proper attribution to the author; no part may be used for commercial purposes directly or indirectly via a for-profit platform; no adaptation or derivative works are permitted without consent from the copyright owner.

Language dc:language.iso

en

DOI

10.22215/etd/2026-16925

OAI identifier oai:identifier

oai:carleton.scholaris.ca:20.500.14718/45082