Ponds and rivers are naturally low in minerals
Water plants grow slowly
If fertiliser washes from farmland
Water plants grow quickly
Plants growing below the surface Don’t get
enough light and die
Dead matter
so but
thenshading
which
releasing
Providing food for
Bacteria and other microbes
whichIncrease in numbers
andUse up oxygen from the water
as they
Carry out aerobic respiration
killingAnimals that cannot tolerate it
