Habitat

The area in which a given population lives, which is distinguished by its physical features and/or main plants.

Hydroponics

Growing plants by using another medium other than soil; when using another medium (e.g. sand or peat), the grower must add a nutrient solution to ensure the plant receives all essential elements to promote normal growth.

Hypoxic zone

Hypoxia is low oxygen. In estuaries, lakes and coastal waters, low oxygen means a concentration of less than 2 parts per million. Example: The Gulf of Mexico hypoxic zone is an area along the Louisiana-Texas coast where water near the sea floor has hypoxic conditions believed to be from excess nutrients delivered by the Mississippi River.