1. Over population
Animal become endangered from loss of habitat
Loss of biodiversity
2. Land clearing
3. Climate change
High water levels
Under oxygenated water
Lack of permanent water
1. Dissolved oxygen
Good for the water
Higher the amount the better the water is
Released by plants and aquatic life
Lower water temp is better
The higher the temperature is, the less amount of dissolved oxygen there is
How clear the water is
The lower the number the cleaner the water is
Run off from the rain
4. PH level
Neural is best (7.0)
Effects of too much phosphates and nitrates in the water:
1 Algae take up the phosphorous and grow too much
2 Algae dies and sinks to the bottom
3 Bacteria at the bottom decompose the dead algae using up oxygen in the process
4 Oxygen levels droop, killing fish or aquatic insects
5 Phosphorous continues to enter the water
6 The cycle continues
Symbiosis - two species living together
Type of symbiosis:
One species benefits and the other is neither harmed nor helped.
Example; epiphytes, a plant, such as an orchid that grows on a tree and is dependent on the tree for mechanical support while the tree is not harmed
One species benefits (parasite) and the other is harmed (host). A parasite taps onto the cellular system of its host.
Examples; lampreys, leeches, fleas, ticks, tapeworms - the host is harmed and the parasite benefits as it obtains nutrients from the host.
Beneficial to both species.
Example; clownfish and the sea anemone. The clownfish protects the anemone from anemone-eating fish, and in turn the stinging tentacles of the anemone protect the clownfish from its predators.
One organism benefit while the other organism is harmed and threatened to die out.
Example; cane toad -- if they lay their eggs in a dam, the native frog species who are in the minority struggle to survive and mature.
Monoculture or Polyculture?
Mono culture Challenges:
Loss of habitat
Examples in Australia
Poly culture is best for the enviroment
Help fight weeds
more effective for farmers