Nutrient Pollution Flashcards
What is nutrient “pollution”?
addition of excess nutrients
What can nutrient pollution in aquatic systems lead to?
fish kills
What are the primary producers in Lake Trafford?
cyanobacteria phytoplankton and green algae phytoplankton
What are the consumers in Lake Trafford?
- Daphnia
- Bosmina
- Trout
What do Daphnia eat?
phytoplankton
What do Bosmina eat?
green algae
What do Trout eat?
Daphnia and Bosmina
What are detritivores in Lake Trafford?
microscopic decomposers
What happens in Lake Trafford when nutrients are low?
trout numbers are very stable
What happens in Lake Trafford when nutrients are very high?
trout numbers stable at first then sudden die-off
What is eutrophication?
body of water receives too many nutrients
When does eutrophication occur?
- when primary producers respond to increase in nutrients, grow to high numbers, give up nutrients, and die
- detritivores use oxygen as feed on dead algae
- trout die of hypoxia
What limiting nutrient often causes eutrophication?
phosphate, which is often at low levels in aquatic ecosystems
What does doubling phosphate levels do?
- doubled green algae population, but cut dissolved O2 in half as dying algae where decomposed
- when P doubled again, algae nearly doubled again, and O2 levels bottomed out
When additional trophic levels are added what happens?
- phytoplankton are eaten and converted to biomass, so much primary productivity doesn’t enter detrital cycle
- green algae don’t increase as much and O2 levels don’t fall as much
