Freshwater biology
[3] Freshwater biology is also used to study the effects of climate change and increased human impact on both aquatic systems and wider ecosystems.
Running, fast-moving waters have a higher oxygen content, allowing different species to thrive and making pollution easier to combat.
For example, the water at the source is clearer, has a higher oxygen content, lower temperatures, and heterotrophs common species.
In the middle, the width usually expands and the species diversity increases due to temperature and oxygen content changes, including aquatic green plants and algae.
The water at the mouth has a lower oxygen concentration and is murkier due to the sediment that has been collected and traveled along the length of the river or stream.
The littoral zone is the uppermost layer and the warmest water found in lakes and ponds, as the sun directly heats is.
[7] This zone hosts the most biodiversity in standing water, with a wide variety of organisms found here, vital to the health of the ecosystem and an important aspect of the diet of organisms in the habitat, like algae, aquatic plants, clams, insects, fish, crustaceans, and amphibians.
This zone has lower temperatures, is fairly well-lit, and is occupied by a smaller variety of organisms, including phytoplankton, zooplankton, and fish.
[7] The plankton found in this zone play a crucial role in the food web of the habitat and support the diet of many important organisms.
During the fall and spring, there is a mixing of layers usually due to wind that circulates oxygen and creates a more uniform temperature throughout the water system.
[6] This area functions in much the same way as the riparian zone, the plants protecting the water from pollution, flooding, and heat stress, while also providing nutrients and habitats for aquatic and wetland species.
Due to the waterlogged and submerged nature of the land, the anaerobic conditions of wetlands are unique and support the highest species diversity of all ecosystems.
Additionally, wetlands provide flood and storm protection, as the system can absorb large amounts of excess water.
[8] Carolina Bays are characterized as elliptical shaped depressions that are surrounded by a sand rim and have a sandy bottom.
Freshwater organism can include invertebrates, insects, fish, amphibians, mammals, birds, aquatic plants, and planktons.
[12] Amphibians, which include frogs, toads, salamanders, and caecilians, are a group that predominately exist in freshwater habitats.
[15] Emergent plants, such as horsetails and cattails, are rooted near the edge of freshwater ecosystems, and commonly stick up out of the water.
[16] The impervious surfaces used in domestic and urban construction replace soil that used to absorb stormwater, increasing the amount of runoff traveling farther distances.
All three of the major contributors to pollution – industry, agriculture, and cities – are commonly found along moving waters, adding to the over-pollution of rivers and streams.
This excessive plant population growth decreases the oxygen content of the water, and other aquatic life suffocates.
The pollution of groundwater is easy to achieve due to the slow circulation of water, even slower than that of lakes and ponds.
The water must navigate through small holes in the aquifer rock, moving on average only a couple of inches each day.
