how does huge alluvial deposits in rivers affect aquatic life?

Question

Is it harmful to have huge alluvial deposits in rivers? why?

If you can, please cite examples

Answer 1

First off, consider the definition of "alluvium" which is what makes up "alluvial deposits":

Alluvium: A general term for detrital deposits made by streams on river beds, flood plains, and alluvial fans; esp. a deposit of silt or silty clay laid down during time of flood. The term applies to stream deposits of recent time. It does not include subaqueous sediments of seas and lakes.

From: Bates, R.L, and J.A. Jackson, 1984, Dictionary of Geological Terms, Third Edition, Prepared by the American Geological Institute. page 15

Rivers could not exist without alluvial deposits in some part of the river. The Mississippi has built alluvial deposits covering large parts of every state along its banks, and indeed the river bottom itself is an alluvial deposit. In contrast, the Colorado River in the Grand Canyon leaves very little alluvium in the canyon, but has built a great alluvial deposit that stretches across southern California, and into Mexico.

Aquatic life in rivers could not live without alluvial deposits. Alluvial deposits support plant life, which in turn supplies food to aquatic organisms. For some bottom-dwelling organisms like fresh-water clams actually live in the alluvium. Others that feed on detritus and algae are things like fresh-water snails. These could not live without alluvium, as it is likely any stream that had a solid rock bottom would be moving too fast for them. Organisms like these are near the bottom of the food chain, supporting fish and higher organisms as a food source.

If your question is about sediment in river water the answer is different. As sediment load gets high in a river there is less oxygen available and survival of most organisms becomes more difficult. In many rivers this type of high-suspended sediment event is sporadic, so aquatic organisms only have to survive it for a short period.

Alluvial deposits themselves are not harmful to ecosystems, but instead support them. At times when river conditions cause those deposits to mobilize and become suspended load they can be detrimental to aquatic organisms for a short period. However, this is the natural way that rivers move sediment, so most riverine organisms have adapted to this type of event.

Answer 2

Acid rain makes the river water polluted. So while fish swim interior the water and stuff they grow to be ill. and distinctive human beings in destructive counties use the river water to take showers and drink and stuff like that. Then those human beings grow to be ill. while acid rain falls on the rivers it specifically impacts the residing beings that use or drink that water. It basically impacts the water via making it impure. Lakes that have been acidified can not help the comparable form of existence as wholesome lakes. As a lake will become extra acidic, crayfish and clam populations are the 1st to vanish, then countless forms of fish. many forms of plankton-minute organisms that kind the foundation of the lake's food chain-additionally are affected. As fish shares dwindle, so do populations of loons and different water birds that feed on them. The lakes, whether, do no longer grow to be completely lifeless. some existence varieties actual earnings from the better acidity. Lake-backside plant life and mosses, working example, thrive in acid lakes. So do blackfly larvae.

Answer 3

In a word NO! Simply -
These deposits provide nutrients for for aquatic flora which in turn provide nutrients for aquatic fauna.