Acid rain from Los Angeles changed the chemistry of the river, resulting in the death of many fish.Due to human activities in Los Angeles, pollution is not anymore shocking. The acid rain would be distributed to the river which would change the environment of the aquatic life.
Assuming this involves another form of shifting tectonic plates, the answer would be earthquakes. Another form of the question is asking for continental drift.
Continental Polar and Maritime Polar ; Polar had a direct connotation with the cold. :)
There are 272 words in the Gettysburg Address!
Sunny~ ☺
