Are global influences of cascade dams affecting river water temperature and fish ecology?

Abstract

Abstract Global warming is affecting animal populations worldwide, through chronic temperature increases and an increase in the frequency of extreme heatwave events. Reservoirs are essential for water security. All watersheds with reservoirs are impacted by their construction. These artificial ecosystems controlled by humans change considerably the natural terrestrial and aquatic ecosystem and systems and their biodiversity. The rapid increase in population growth, urbanization, and industrialization are accompanied by an increase in river discharges, which increases the total amount of pollutants. HMs contamination in aquatic environments, as well as the subsequent absorption of HMs into the food chain by aquatic creatures and people, endangers public health. Multiple uses of reservoirs promote benefits in terms of economic development, income, and employment. HMs in water can be ingested directly by aquatic species like fish and can also be ingested indirectly through the food chain; thus, it is much more important and required to conduct frequent monitoring of the aquatic environment. As a result, this review summarizes knowledge about the effects of cascade dams on river water temperature and increases on the stress physiology of fishes, and adaptation to climate change is also needed to produce more fish without global warming.

Keywords

• Global water temperature
• Global warming
• Three Gorges Dam (TGD)
• Fish behavior
• Cascade reservoir
• Heavy metals