What does a decrease in salmon population due to an increase in river temperature indicate?

Question

What does a decrease in salmon population due to an increase in river temperature indicate?
A) an abiotic factor affecting a biotic factor
B) change in population but not in abiotic factors
C) an effect of predation
D) an unchanging biological community

Answer 1

This is actually a pretty simple answer. I'll give a quick case to show my point. Right now I live in the upper Midwest, and long ago salmon have been planted in the great lakes. There are a few streams and rivers that have natural reproduction. Depending on the weather that year, salmon will successfully spawn. The factor that determines whether or not they eggs with survive......is temperature. If that water is too warm the eggs will die. Salmon smolt and eggs need colder water to live. If you get a warm fall or very little rain the water will warm and the eggs will die. On the other hand if you get too much rain and the rivers get very turbid the eggs get covered in silt and bye bye baby salmon. Also the same thing is true where I lived in Alaska. King salmon spawn in the spring there (in the Midwest they spawn in fall) and if the summer is very warm with little rain....you will get a poor return the next year. It's OK though, salmon do compensate for this. Every year a handful of 3 or 5 year old salmon do return. So in case there is a die off of that 4 year old class, the cycle will still go on...and on...and on... so to answer you: A

Answer 2

Nothing, the change can be over fishing, not related to temperature at all or all four of your answers. The problem and fish population would need be studied for sereral years to gain any kind of glue of the change. The Salmon may have frond a cleaner river.

Answer 3

Too many dammed rivers and diversion of the natural flow of most of the rivers on Earth. We should not be damming the rivers and should be removing dams that are in use. The water can be replaced by desalination and the power by other solar energy. The way water is now used is too old and new ways to get what water we need have to be developed.

Answer 4

there'll be some adjustments, yet for the main area, river flows will shrink. international warming is already inflicting shorter and drier winters, which appreciably cut back snowpack. This ends up in much less runoff while the snow melts interior the spring. In some aspects this could be offset via bigger rainfall, however the ordinary type would be a shrink in flows.

Answer 5

my guess is A.