Abstract Long-chain alkenones (LCAs) have been used for decades to reconstruct quantitative sea-surface temperature records, but they also have a great potential for paleotemperature reconstructions in lacustrine settings. Here, we investigated how the presence and abundance of LCAs in surface sediments from 106 lakes varied with environmental conditions in lakes of the northern Great Plains (Canadian Prairies) in southern Saskatchewan, Canada. Consistent with preliminary research, we found LCAs in 55% of surveyed lakes, with mean concentrations of 143 μg/g dry sediment, but very high concentrations (up to 2.3 mg/g dry sediment) in 7% of lakes. Statistical analyses indicate that salinity and stratification play key roles in determining LCA presence and abundance supporting previous research in Spain and the northern Great Plains, USA. Overall, the alkenone unsaturation index ( U 37 K ) was not correlated significantly with average summer water temperature, probably because the timing of maximum LCA production occurs during the spring season. We conclude that improved seasonal sampling is required within the study lakes to better identify the timing and habitat of haptophyte production, and allow development of environmental temperature reconstruction tools.

中文翻译：

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评估对加拿大大草原长链烯酮分布的环境控制

摘要 几十年来，长链烯酮 (LCA) 已被用于重建定量的海面温度记录，但它们在湖泊环境中的古温度重建方面也具有巨大的潜力。在这里，我们调查了 106 个湖泊表层沉积物中 LCA 的存在和丰度如何随加拿大萨斯喀彻温省南部大平原北部（加拿大大草原）湖泊的环境条件而变化。与初步研究一致，我们在 55% 的调查湖泊中发现了 LCA，平均浓度为 143 μg/g 干沉积物，但在 7% 的湖泊中浓度非常高（高达 2.3 mg/g 干沉积物）。统计分析表明，盐度和分层在确定 LCA 存在和丰度方面起着关键作用，支持之前在西班牙和美国大平原北部的研究。全面的，烯酮不饱和指数 (U 37 K ) 与夏季平均水温没有显着相关性，可能是因为 LCA 产量最大的时间发生在春季。我们得出的结论是，研究湖泊内需要改进季节性采样，以更好地确定触生植物生产的时间和栖息地，并允许开发环境温度重建工具。