Aquatic Environments and Freshwater Habitats

Water environments vary significantly in their physical and chemical characteristics, leading to distinct types of life.

Freshwater habitats have a low salt concentration and are crucial for human life.

Freshwater organisms are exposed to the risk of being swept away by currents. They have evolved adaptations to stay in their environments.

Freshwater organisms often have suckers, specialized fins, or other features to help them attach to surfaces and avoid being carried away by currents.

Some freshwater organisms can tolerate brackish water, a mixture of salt and fresh water, allowing them to move between environments.

Freshwater organisms are generally smaller than their marine counterparts.

Freshwater habitats are classified based on water movement, with lentic habitats being still water and lotic habitats being flowing water.

Lentic (still) waters include lakes and ponds, which are relatively stable bodies of water.

Water bodies larger than ponds. They are usually deeper, have a larger surface area, and exhibit thermal stratification in some seasons.

The process by which a lake basin is formed. This can be due to geological movements, volcanic activity, ice, landslides, or even the actions of animals and plants.

Lakes formed by volcanic activity are often round, while lakes formed by tectonic movements can have crescent shapes. The shape is influenced by the process that created the basin.

Newly formed lakes have a rocky or sandy bottom with minimal sediment. As time passes, the lake accumulates more sediment and organic matter.

Scientists have tried to classify lakes based on their formation and the surrounding geography. However, the overlapping characteristics of lakes make classification difficult.

The area of a lake farthest from the shore is important for its productivity. This is because it's colder and contains more nutrients.

Water movement prevents thermal stratification in ponds. However, the larger size of lakes allows temperature layers to form in deeper parts during certain seasons.

External factors such as dams, canals, and changes in water outflows can alter the characteristics of a lake.

Lakes that are rich in nutrients, particularly phosphorus and nitrogen. Shallow with large beaches and a deeper lower layer. They have abundant biomass and low oxygen levels in their deeper regions during summer.

Lakes that are low in nutrients and have a high oxygen content, even in their deeper layers. They are also typically deep with smaller coastal areas.

Lakes with intermediate characteristics between oligotrophic and eutrophic lakes. They have moderate nutrient levels, oxygen content, and biomass.

Lakes that are often found in mountainous or swampy regions and are high in organic matter. They have a high concentration of humic acid, which gives the water a brown color and makes the water acidic.

A warm, upper layer of water in a lake, found during the summer season.

A cold, lower layer of water in a lake, found during the summer season.

A transition zone between the Epilimnion and Hypolimnion in a lake. It is characterized by a rapid change in temperature.

Water bodies that exhibit continuous movement in one direction, such as rivers and streams.