Oceans

4. The narrow ocean margin between the high-tide mark and the low-tide mark.
6. The natural environment in which a living thing gets all that it needs to live; examples include a desert, a coral reef,and a freshwater lake.
8. A built-up limestone deposit formed by small ant-sized organisms called corals.
10. A shoreline area where fresh water from a river mixes with salt water from the ocean.
12. The measure of the amount of dissolved salt contained in water.
13. An opening in the sea floor from which heated water rises and mixes with the ocean water above.
15. Microscopic floating organisms that live in water and, like plants, convert sunlight and carbon dioxide into food.
17. A mass of moving ocean water.
19. The flat or gently sloping land that lies submerged around the edges of a continent and that extends from the shoreline out to the continental slope.
20. The movement of water from the surface to greater depths.

1. The overall direction and movement of water as waves strike the shore at an angle.
2. A large community of kelp, a type of seaweed that can attach to the ocean floor.
3. A narrow stream of water that breaks through sandbars and drains rapidly back into deeper water.
5. A wet,swampy area that is often flooded with water.
7. A system that uses underwater sound waves to measure distance and locate objects.
9. The portion of animals that are caught in a net and then thrown away as unwanted.
11. A property of matter representing the mass per unit volume.
14. A disturbance of wind patterns and ocean currents in the Pacific Ocean that causes temporary climate changes in many parts of the world.
16. The catching of fish at a faster rate than they can reproduce.
18. The vertical movement of deep water up to the surface.