Across
- 1. nonliving things in an ecosystem
- 3. sticking together
- 8. safe to drink
- 10. underwater vehicle
- 11. person who studies the ocean
- 13. organisms that can support without environmental degradation.
- 17. restricting the size of a population
- 18. the portion of land drained by a river
- 19. area of land where all of the water that falls in it and drains off
- 20. interaction between organisms
Down
- 2. the zone of air, land and water where organisms exist
- 4. protection of the natural environment
- 5. concentrated mixture of nitric and sulfuric acids
- 6. amount of dissolved calcium and magnesium in the water
- 7. further divided into regions by depth
- 9. delicate powdery surface
- 12. living things in an ecosystem
- 14. manned deep-ocean research submersible
- 15. detection of objects under water
- 16. variability among living organisms