Aquatic

12345678910111213141516171819202122
Across
  1. 1. of fish that migrates upstream to spawn (5)
  2. 4. form of H₂O (5)
  3. 5. dolphins, and porpoises (9)
  4. 6. plant that supports aquatic food chains (5)
  5. 8. drifting organisms that photosynthesize (8)
  6. 10. lack of oxygen in water (7)
  7. 13. area where river meets ocean (7)
  8. 17. of water changing to vapor (10)
  9. 19. Level
  10. 20. of salt in water (9)
  11. 21. that is not salty (10)
  12. 22. Large body of salt water (5)
Down
  1. 2. indicator species (4)
  2. 3. with a shell and claws (5)
  3. 7. to measure ocean depth (6)
  4. 9. of inland waters (10)
  5. 11. ocean zone with no light (8)
  6. 12. of water caused by wind or tides (7)
  7. 14. Key
  8. 15. from farms or streets (6)
  9. 16. of dissolved oxygen in water (6,7)
  10. 18. ecosystem near the shore (7)