river pollution + fertilisers

Cards (14)

micro-organisms like bacteria feed on organic waste.
organic waste includes:
sewage
paper
waste food
when bacteria pollutes a river, what happens?
it uses up most of the oxygen
what is a indicator species?
they indicate how polluted an area is
summarise river pollution  
high levels of organic waste in the river
bacteria take oxygen and increase quickly
level of oxygen decreases
other organisms die from lack of oxygen
explain rivers before pollution:
high oxygen
low pollution
high biodiversity
explain rivers after pollution:
low oxygen
high pollution
low biodiversity
nutrients are chemicals that organisms need to stay alive and grow
nitrates are used to make a protein.
80% of the air is nitrogen gas.
why do living things need nitrogen?
to make protein
plants absorb nitrogen in the form of nitrate.
Describe the use of nitrates in a plant
to make proteins/amino acids
Give the term that describes the increased growth of algae caused by leached nitrates
algal bloom