That pond behind your house is a freshwater habitat. So is the stream running behind your school. Freshwater habitats are any natural water sources that don’t contain salt. They include ponds, wetlands, rivers, streams, swamps, marshes and creeks.
Lakes and ponds high in the mountains usually have clean, pure water. This water has few dissolved nutrients. Plankton doesn’t grow particularly well here, but the water is rich in oxygen, which animals need to survive. These freshwater habitats are a good place for fish and insects to live.
Lakes, ponds and streams in lowland areas tend to have more dissolved nutrients, which encourages plankton to grow. This water doesn’t contain as much oxygen, which fish and other animals need to survive.
- Even a dried creek bed may contain life. Some amphibians and insects can burrow into the mud and survive for months or even years. Once heavy rains come, they reappear.
- Phosphate runoff from lawn fertilizers can pollute rivers, ponds and streams. The phosphates encourage plankton growth. If the plankton grow too much, they remove oxygen from the water and other animals die.
- Plankton, or algae, are single-celled organisms that provide food for many small animals. They aren’t plants, but they make food using photosynthesis.
- The babies, or larvae, of many flying insects live in the water and eat algae. Watch for dragonflies or mayflies the next time you’re near a pond.
- Plankton can’t survive in fast-flowing water, such as rivers, which is why you won’t find a lot of animals here. Some fish, such as salmon, choose these places to lay their eggs because predators are few.
- Marsh: a wet, boggy area filled with water plants, brackish water and animals
- Dissolve: break into tiny pieces
- Phosphate: a plant nutrient found in fertilizers
Head over to the University of California to learn more about freshwater biomes.
Question: Are all lakes freshwater lakes?
Answer: Some lakes are full of dissolved soda or salt, making them inhospitable to most life.