What Are Three Natural Disasters That Can Affect Fish?

About

• Natural disasters are considered destructive events that occur in nature and are not caused by human beings. These disasters can include volcanic eruptions, hurricanes, tornadoes, blizzards and landslides. Many times these natural disasters will occur in tandem, such as a tsunami will often follow an earthquake. Because of the dependent relationship between natural disasters and ecosystems, a seemingly unrelated disaster thousands of miles away can adversely affect fish and wildlife.

Tsunamis

• Tsunamis are large waves that are commonly caused by earthquakes, tectonic plate shifts, or the moving of ocean floor debris after these shifts. While at sea, these tsunami waves are small and cause little damage to the creatures living below. Once they reach shore, however, they gain in size and intensity due to the shallower coastal waters. Tsunamis have been known to destroy offshore coral reefs, which can kill the fish that rely on these reefs for food and shelter. Since other deep-sea fish and mammals also rely on these reefs for sustenance, they can also be negatively affected by tsunamis.

Flooding

• Flooding occurs in low-lying areas, commonly in riverbeds and creeks, which are common homes for freshwater fish. Flooding is caused by sudden downpours or sustained long periods of rain. Flooding can cause the sudden creation of new streams and creeks, which can cause fish displacement, leaving fish stranded in disconnected pools without a food source. Additionally, flooding can cause river water to flow faster, displacing river bottom sediment. Fish and other invertebrates that rely on river bottom sediment and organisms for food may have more difficulty obtaining their sources. This is especially true of young fish who are not strong or hearty enough to sustain long periods in these turbulent waters.

Droughts

• A lack of water can cause just as much damage to fish populations as an excess of water. Droughts are caused by extended periods of high temperatures without rain. Rain serves to both refresh streams, lakes, rivers and ponds, as well as to reduce the overall temperature. High temperatures can cause the evaporation of existing bodies of water. As water evaporates, fish become more crowded and food sources become scarcer. Oxygen depletion is also a large problem during droughts, as the smaller body of water produces less oxygen than the larger bodies. Additionally, as streams and creeks dry up, fish can also become stranded without food sources.