Scientists monitor algae to detect changes in water temperature, pollution, and nutrient levels. They use algae as “sentinels” because their rapid life cycles and direct absorption of nutrients make them immediate responders to environmental shifts. By monitoring changes in algal density, species composition, and pigments, researchers can detect early signs of eutrophication, warming sea temperatures, and chemical pollution before these impacts reach higher trophic levels. Advanced techniques like DNA sequencing and AI-driven satellite analysis allow for real-time tracking of these shifts, using algae populations to forecast ecosystem instability and the onset of harmful blooms.
Source: Qi L.(2026). “Global floating algae blooms are expanding.” Nature Communications.