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South Korea Green Algae Alert

Green algae cover the lake at Daecheong Lake in Daejeon, South Korea, on August 23, 2025. Green algae blooms occur when nutrients like nitrogen and phosphorus from land are washed into water bodies by rain, and water temperatures rise, creating ideal conditions for harmful cyanobacteria to thrive. Cyanobacteria, a type of phytoplankton, are essential components of aquatic ecosystems. However, when they proliferate excessively, they can produce foul odors, degrade water quality, and even cause fish deaths. This year, green algae in Daecheong Lake begin spreading in the latter part of last month. (Photo by Seung-il Ryu/NurPhoto)

Photo ID	#12665778
Date Taken	22 August 2025
Location	N/A
Photographer	Seung-il Ryu/NurPhoto
Category	Environmental Issue
Copyright	© 2026 NurPhoto - Seung-il Ryu/NurPhoto

Green algae Green alga Climate change Environment Heat wave Temperature Daejeon South Korea Green algae Daecheong Lake Algae blooms Nutrients Nitrogen Phosphorus Water bodies Rain Water temperatures Cyanobacteria Phytoplankton Aquatic ecosystems Proliferation Foul odors Water quality Fish deaths Spread August 2025 Seung-il Ryu NurPhoto Harmful algae Environmental impact Lake ecosystem Excessive growth Algal bloom causes Land runoff Temperature rise Ecosystem degradation Harmful microorganisms Water pollution Lake contamination.