toxic

blue

green

algae

floating

water

river

pond

lake

pollution

contamination

dirty

cyanobacteria

cell

microbe

bacteria

bloom

poisonous

organism

photosynthetic

surface

environment

liquid

particle

harmful

spring

texture

natural

ecology

microbiology

nature

chemical

climate

background

abstract

disaster

problem

spot

pattern

swamp

color

ecosystem

infested

growth

summer

wet