Across
- 3. filled with different lifeform
- 5. a triangular deposit
- 7. a deep, narrow passage surrounded by steep canyon walls
- 8. a region in or near an ocean where human activity is limited in order to preserve marine life
- 11. one-celled organisms that can cause diseases
- 12. to supervise
- 13. a substance that makes the environment and water dirty
- 15. deep and wide enough to allow boats or ships to sail in
Down
- 1. an energy source such as coal, oil, and natural gas, formed by the fossilized remains of plants and animals
- 2. the growth of large cities
- 4. to die from lack of oxygen
- 6. poisonous
- 9. a scientist who studies oceans and marine life
- 10. An underground rock layer containing water
- 14. the natueal home of a living thing