Hypoxia and Medicine

Question About Fish In A Pond?

Which of the following conditions will most likely result in anoxia effect and may kill the largest number of fish in a pond? a) a cold day during an algal bloom b) a hot day during an algal bloom c) a cold night during an algal bloom d) a hot night during an algal bloom e) a cold day

Public Comments

1. B, Algal blooms first create some dissolved oxygen, but then they over populate since they're free floating, block the sun, use all the DO and the fish die. HA! I will not fail that AP bio exam!
2. The heat during the day would not bother the dissolved oxygen content assuming that the algal bloom was sufficient to cover the greatest majority of the water's surface. If not, a hot day with an algal bloom would most likly result in anoxia. The reasoning behind a hot day and not a hot night is that during the night, air currants are produced between the land and water due to rapid cooling of water and slower cooling of land. This would cool the water faster. Cold water, BTW, holds more dissolved oxygen than warm water.