1. Aquatic Biomes Chapter 10 Section 1

2. An aquatic habitat is one in which the organisms live in or on water. Aquatic biomes and their ecosystems are scattered and are often determined by depth rather than location. For aquatic biomes, two of the most important factors are the amount of dissolved salts in the water and the depth of the water. The rate of flow and the amount of dissolved oxygen in the water are also important.

3. Aquatic biomes can be divided into two main groups: saltwater and freshwater. Ocean water has a good deal more than the water in most lakes, ponds, and streams. The amount of dissolved salts in a sample of water is called salinity. Water that is more saline than fresh water but less saline than ocean water is called brackish water. Brackish water is common in areas such as river deltas and coastal marshes, where fresh water meets the ocean.

4. The amount of sunlight is important in determining the types and amounts of plants that can grow at various depths. As the producers in the ecosystem, plants form the base of the food web. The top layer of water, which receives sunlight, is called the photic zone. The floor of a body of water is called the benthic zone.