Hot weather the cause of Delaware County fish deaths

Environmental officials have determined the cause of death for 1,000 in Ridley Park Lake earlier this month. It’s the same thing officials warn elderly residents and young children about: heat.

Temps rose in the lake ahead of the June 11 fish kill, causing a lack of oxygen, Health & Science reporter Carolyn Beeler explains. The combination of rising water temperatures and oxygen-sucking algae blooms proved too much for the fish, who asphyxiated.

Environmental experts say human interference from things like fertilizer and lawn nutrients can also lower the lake’s oxygen levels.