The Fishkill

since i'm posting my "artistic rendition" of a fishkill here, anyway, i might as well add some educational stuff about it, too, since i also researched on it for the comic strip. Ok, here goes...

Fishkills can be caused by three major factors: toxic discharges (chemical), diseases (biological), and oxygen depletion (physical). Usually, though, the cause is a combination of these (that is, when the environment is critical for fish because of low oxygen or poisonous pesticides, for example, they're more vulnerable to disease). Oxygen depletion is the most common cause, a result of TOO MANY algae or plants in the water (when the water turns really green) because of fertilizers or sewage that run off into the sea from the land. Algae and plants are essential food for the fish, but when they die, the decomposition process uses up the oxygen in the water. Also, when there's no sunlight (cloudy or nighttime), plants use up oxygen instead of producing it.

The solution? Plant more trees, especially around farms, and treat sewage (and other nutrient-rich waste) before discharging it into the sea.