underwater
environmental
bad
black
canal
chemical
contaminate
contaminated
danger
dangerous
dark
dead
dead fish
death
dirty
disaster
disease
ecological
ecology
ecosystem
environment
fish
float
garbage
harmful
industry
lake
life
nature
poison
pollute
polluted
pollution
problem
river
rotten
sewage
smell
stink
toxic
unhygienic
waste
water
water pollution