Browning of lakes is a global concern. Browning causes shifts in the cycles of important elements, which influences biological communities of lakes. However, we have limited information on the historical associations among lake water color, elemental composition, and communities, especially in small lakes, even though they dominate the global lake area. This project aims to use dormant eggs (ephippia) of water fleas from dated lake sediment profiles to reconstruct past lake conditions. We will conduct laboratory and field studies to show that lake water concentrations of important elements can be inferred from the elemental composition of ephippia. Then, our team will apply this tool to study how lake biogeochemistry has changed over time in response to browning of small Arctic and Boreal lakes. We will combine this information with other proxies to show how browning has changed – and is still changing - the structure and function of small lakes.

2024

2028