Urban wildfires disrupt streams and their tiny inhabitants − losing these insects is a warning of bigger water problems

Ash from fires often washes into streams, where it can wreak havoc on ecosystems. Lauren Magliozzi, CC BY-ND

A tiny, vibrant world thrives along the rocky bottom of most streams. As sunlight filters through the water, mayfly nymphs, no larger than your fingernail, cling to algae-coated cobbles. Their brushlike mouthparts scrape the greenish coating, leaving faint trails as they feed. Six spindly legs anchor them against the current, while feathery gills wave gently, drawing oxygen from the flowing water.

This scene is common in well-maintained creeks and streams that flow through populated areas. But when wildfires sweep through, the toxic materials left behind can devastate this ecosystem.