How can use of river bed for recreational activities cause environmental problems/?

Question

like allowing the use of river bed (if th eriver passes through city) for exhibitions, circus etc.

Answer 1

There are many problems that can occur.

1.) People leaving their trash (cans, bottles, papers, etc) near the river or dumping them in the water. This can cause harm to birds who may accidentally eat plastic or indigestable items.  

2.) People causing disruption to the sediments.  The turbidity will cause probelms for the organisms. If the turbidity is constant for a while, it may disrupt the amount of light reaching any plants growing at the river bottom.

3.) Erosion. If people are walking on the banks, vegetation may be damaged and cause massive erosion.  When it rains, there will be no grass or other plants soaking up the water or keeping the sand from falling into the river.

4.) Pollution: chemicals and other harmful toxins will cause harm to any of the organisms in the river.  Fish, plants, microorganisms, frogs, etc.  This may disrupt the food chain and equilibrium of the ecosystem.

I hope this helped!

Answer 2

Because the turbulence will stir up sediment sending it down stream choking out fish and other aquatic life. Also if you are talking in a city there could be the possibility of contaminated sediment that would get stirred up as well.