WHAT ARE SOME MAJOR HUMAN IMPACTS ON AQUATIC ECOSYSTEMS? Kakakakimmi & Geoffrey

Leaching  Natural leaching: nutrients seeps out of soil and causes it to flow into rivers and streams without the help of humans.  Chemicals from fertilizers and pesticides tend to leach and make the water unsuitable for life.  Sulfurous compounds make water more acidic and can cause acid rain.  Oil can cover plants and animals making them unable to fly or photosynthesize

Deforestation  Eliminates plants whose roots hold soil in place  Causes runoff and increases rate of erosion  Sediment from runoff clouds up water and affects photosynthesis  May cause floods from the lack of absorption into the soil

Dams  Affect fish migration and mating.  Floods ecosystems and dries others.

Excess nutrients  Fertilizers or other sources of nutrients raise the nutrient level and cause algae blooms.  Dead algae sinks and takes out oxygen from the water.

Agriculture and Irrigation  Grazing promotes runoff and increases sediment  Livestock have contaminants and potentially dangerous bacteria that can kill plants and animals.  Irrigation lowers water levels of rivers and streams

Debris (aka litter)  Choking hazard for birds and fish  Blocks sunlight from penetrating water  May seep out chemicals  Clogs waterways

Alien species  May become invasive and kill off native plants an animals  May cause extinction