Across
- 3. Occurs when a fish population is being depleted fast than it can reproduce itself
- 5. Salt water ecosystems and organisms
- 6. Organisms that float in the water and drift with the currents
- 8. Water held beneath the Earth's surface
- 9. The process of dragging huge, heavy nets over the sea floor, scooping up everything in its path
- 10. The release of oil into the environment caused by natural causes or human activity
- 12. A man-made, underwater structure
- 16. The introduction of harmful substances or products into the environment, usually as a result of human activities
- 17. Water that is above the Earth's surface
- 18. An area of land where all of the water drains into the same body of water
- 20. The water flow that occurs when waer from rain, snowmelt, or other sources flows over the land
- 21. Property of being acidic, Substances with pH values between 0-7
Down
- 1. Polkution that cannot be traced to a specific source
- 2. Measurement of how acidic or basic a substance is
- 4. An underground treatment system for household sewage
- 7. An underground rock formation where water collects
- 11. A stream that flows to a larger stream or other body of water
- 13. Precipitaion containing acids that form in the atmosphere when industrial gas emissions and other pollutants combine with water
- 14. tThe area of land that allows water to replenish an aquifer
- 15. Property of being a base, substances with pH values between 7-14
- 16. Anything capable of causing disease
- 19. The removal of sediment from the bottom of sea or river