Agricultural runoff, containing fertilizers, pesticides, and animal waste, is a significant source of water pollution in rivers and lakes.

Dams and reservoirs alter the natural flow of rivers, affecting sediment transport, nutrient cycling, and aquatic habitats.

Eutrophication is primarily caused by excessive nutrient input, often from agricultural runoff or wastewater discharge.

Urbanization leads to increased impervious surfaces, reducing water infiltration and causing stormwater runoff, which degrades water quality.

Recreational activities, such as boating and fishing, can introduce invasive species into new ecosystems through the release of bait or the transport of aquatic plants.

Deforestation reduces shade, leading to increased water temperature, which can harm aquatic life and disrupt ecosystem balance.

Overfishing leads to the decline of target fish populations, disrupting the food web and ecosystem balance.

Climate change alters water temperature and flow patterns, affecting aquatic habitats, species distribution, and ecosystem functioning.

Industrial activities, such as mining and manufacturing, release heavy metals into the environment, which can contaminate water bodies.

Levees and embankments alter sediment transport patterns, affecting nutrient cycling and aquatic habitats.

Industrial emissions, particularly sulfur dioxide and nitrogen oxides, contribute to acid rain, which leads to the acidification of water bodies.

Dams and reservoirs alter nutrient cycling patterns, affecting primary productivity and ecosystem functioning.

Urbanization contributes to plastic pollution through stormwater runoff and improper waste disposal.

Roads and highways increase impervious surfaces, leading to increased stormwater runoff and reduced water infiltration.

Habitat destruction leads to the decline of native species, disrupting ecosystem balance and biodiversity.