A 140-year paleolimnological record of climatically and anthropogenically driven eutrophication in Utikuma Lake, Alberta, Canada

Eutrophication brings a plethora of environmental and economic consequences to lakes, including ecosystem degradation, increased health risk due to the emergence of harmful algal blooms, and disrupts tourism, recreation and fishing industries. A 140-year core record from Utikuma Lake, Alberta, Canada (55.87° N, 115.42°W), uncovered the mechanisms contributing to the lake's current hypereutrophic state. ITRAX X-ray fluorescence (XRF) element/ratios and end-member modeling analysis (EMMA) of the core sediment grain size data identified variation in the core profile linked to specific sedimentological processes. XRF results exhibited changes in precipitation, weathering, and catchment runoff (Ti, Fe, K/Rb, Ca/Sr) and in lake productivity over time (P, S, Si/Ti). Five derived end members (EMs) were identified: EM01 (mode = 1 µm), low-energy catchment erosion from moderate precipitation events; EM02 (mode = 9 µm), warm spring low-energy freshet; EM03 (mode = 44 µm), cold spring high-energy f..., Gravity cores were collected with a UWITEC corer in June 2022. Cores were subsampled at 1-mm resolution using a portable, high-resolution sediment core extruder. Subsamples were refrigerated and transferred to Carleton University for analysis. The subsamples were preprocessed for grain size analysis using a three-step digestion process to dissolve carbonates (addition of 10% HCl), oxidize organic matter (addition of 30% H2O2), and remove biogenic silica (addition of 0.2 M NaOH). The subsamples were then analyzed using a Beckman Coulter LS 13 320 laser diffraction particle size analyzer equipped with a universal liquid module to yield a grain size distribution ranging from 0.375 μm to 2,000 μm. This data subsequently used for End Member Modelling Analysis (EMMA), which produced five end members. The core material was also scanned by a Cox ITRAX XRF Core Scanner at McMaster University. The subsamples were homogenized and loaded into sequential sediment reservoir trays. They trays were the..., , # A 140-year paleolimnological record of climatic and anthropogenically driven eutrophication in Utikuma Lake, Alberta, Canada

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Paleolimnological data from Utikuma Lake, Alberta, Canada (55.87° N, 115.42°W) is presented. This data was derived from analysis of gravity cores retrieved from the lake using UWITEC core barrels in June 2022. Grain size and End Member Modelling Analysis (EMMA) and ITRAX-XRF analysis were carried out on 1-mm subsamples of core BU-1. Five robust end members (EMs) were found. Pb-210 dating of the core BU-4 indicated that the upper 20 cm of the cores span approximately 140 years. The sedimentary record from Utikuma Lake archives both natural and anthropogenically driven changes, including the shift towards hypereutrophication that began in the mid 1990s.

## Description of the data and file structure

File list:

File 1 name: BU1_PSA.csv
File 1 description: particle size analysis bins in microns and associated calendar dates for Utikuma Lake core BU-1. Grain ...