eutrophication

the nitrogen cycle

1. nitrogen fixation - N2 to NH4

2. ammonification - decomposer to NH4

3. nitrification - NO2 - NO3

4. assimilation - NO3 to autotroph

ammonium

(NH4) toxic to plants

nitrites

(NO2) toxic to plants

nitrates

(NO3) vital for growth and passed up through trophic levels, eventually absorbed by humans

eutrophication

process where excess nutrients saturate the water near areas of terrestrial runoff, resulting in algae blooms

non-point source pollution

agricultural runoff is often linked to eutrophication

nitrogen (non point pollution)

synthetic fertilizer and animal waste runoff into streams and makes their way to larger bodies of water via watershed

phosphorus (non point source of pollution)

other fertilizers contain mineral phosphorus to further stimulate plant growth which can also run off into the watershed

deadzones

areas form in the water when aerobic bacteria decompose the dead plant matter

• marine organisms die off due to decreased dissolved oxygen

algae blooms

surplus of nutrients cause rapid algae growth

• produce toxins

• deplete oxygen in water

• blocking sunlight

• disrupting food chains