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Environmental Science

The Causes and Consequences of Lake Stratification Turnover

Quick fact

In deep temperate lakes, autumn turnover can mix nutrient-rich deep water all the way to the surface in just days, sometimes triggering massive algal blooms and fish kills as the ecosystem rebalances.

Why this is interesting

You might think a lake is a single, evenly mixed body of water—but in summer it's actually a layered cake of warm, middle, and cold water that barely mixes. Why does this delicate layering, and its sudden collapse in autumn, sometimes kill thousands of fish?