1. How can abiotic factors affect plant and animal distributions in freshwater and marine ecosystems? ➢ 1) Pollution ➢ 2) temperature ➢ 3) dissolved oxygen ➢ 4) phosphates ➢ 5) ph ➢ 6) turbidity ➢ 7) upwelling

2. Pollution Pollution is any harmful material that is released into the environment. ➢ It can be natural or a result of human activities. ➢ Most pollution in the world’s oceans is found along the coastlines.

3. Direct and Indirect Pollution Direct (from one source) examples of pollution include: ➢ Landfill leaks ➢ Industry dumping waste water ➢ Oil spills ➢ Sewage systems Indirect (from many sources) examples of pollution include: ➢ Oils leaks from cars and trucks on roads ➢ Pesticides and fertilizers from lawns, farms, golf courses, ➢ animal waste from farms ➢ runoff from city streets

4. Temperature ➢ temperature- warm water hold less dissolved oxygen than cold water. (The more dissolved oxygen there is the better for living organisms)

5. Dissolved Oxygen The amount of dissolved oxygen in the water may depend on several factors: abiotic (non-living) factors: ➢ Colder, moving water holds more dissolved oxygen biotic (living) factors: ➢ living things consume dissolved oxygen in water ➢ Too many dead organisms cause decomposers to use up available oxygen ➢ Lack of oxygen kills the organisms that need it. ➢ Dissolved oxygen levels should be 5 mg/L (or 5 ppm) or greater

6. Phosphates ➢ Phosphates are substances occurring naturally in the soil which enhance plant growth. ➢ Phosphates can become a problem in water systems: excess plant →decomposition → low oxygen levels ➢ Phosphate levels should be less than 10 μg/L

8. pH ➢ pH scale 0------------------------7-----------------------14 Acids NeutralBases ➢ Acid rain, formed as a result of pollution, can affect pH. ➢ Water pH should be in the range of 5 to 8.5, if not plant or animal life may begin to die.

9. Turbidity ➢ Turbidity is the amount of undissolved solids suspended in the water (cloudy water) turbidity ↓ blocks sunlight ↓ less photosynthesis ↓ less O2 produced ↓ organisms begin to die

10. Upwelling ➢ Upwelling is the vertical motion of water in the ocean (subsurface water of lower temperature and greater density moves toward the surface of the ocean) upwelling →nutrients→ plant life → attracts animal life

11. The End