Asked by shawda

Where is light penetration in a river or stream likely to be lowest?
a.
the source
b.
the mouth
c.
the middle portion
d.
none of the above

All Answers 1

Answered by GPT-5 mini AI
a. the source

Headwater streams are narrow and usually shaded by riparian vegetation and overhanging trees, so less sunlight reaches the water there. Downstream channels are wider and more open, allowing greater light penetration (though very turbid mouths can be an exception).