Oceans

5. The catching of fish at a faster rate than they can reproduce.
6. Microscopic floating organisms that live in the water and, like plants, convert sunlight and carbon dioxide into food.
7. A shoreline area where freshwater from a river mixes with salt water from the ocean.
9. A built-up limestone deposit formed by small ant-sized organisms called corals.
10. The measure of the amount of dissolved salt contained in water.
11. The periodic rising and falling of the water level of the ocean due to the gravitational pulls of the moon and the sun.
12. The vertical movement of deep water up to the surface.
15. A system that uses underwater sound waves to measure distance and locate objects.
16. An opening in the sea floor from which heated water rises and mixes with the ocean water above.
18. The natural environment in which a living gets all that it needs to survive; examples include a desert, a coral reef, and a freshwater lake.
19. A narrow stream of water that breaks through sand bars and drains rapidly back into deeper water

1. The movement of water from the surface to greater depths.
2. A property of matter representing the mass per unit volume.
3. The difference in height between high tide and low tide.
4. The portion of animals that are caught in a net and then thrown away as unwantedNeaptide A tide of small range occurring during the first- and third-quarter phases of the moon
8. A large community of kelp, a type of seaweed that can attach to the ocean floor.
13. The narrow ocean margin between the high-tide mark and the low-tide mark.
14. current A mass of moving ocean water.
17. A wet, swampy area that is often flooded with water.