Extreme drought amplifies the dominant role of Secchi depth on the underwater light environment: evidence from Poyang Lake

Key Points

• Changes in Secchi depth are closely linked to variations in underwater light clarity, especially during extreme drought conditions.
• Extreme drought periods resulted in a notable increase in light attenuation metrics at Poyang Lake.
• Assessment of environmental samples and data over several drought years highlights the critical impact of drought on aquatic ecosystems.
• Findings suggest that monitoring Secchi depth is crucial for understanding light conditions in freshwater bodies during climate extremes.