A large number of fish are suddenly found floating dead on a lake. You are called in to investigate the problem. You find an abundance of phytoplankton and no evidence of toxic dumping. Suggest a reason for the fish kill
What will be an ideal response?
A very likely reason for the fish kill is low oxygen level in the lake. A source for the nutrient enrichment should be located, as this was the first step in the process. "Nutrient enrichment allow(ed) the rapid growth and multiplication of phytoplankton, increasing the turbidity of the water. The increasing turbidity shade(d) out the SAV that live in the water. With the die-off of SAV, there (was) a loss of food, habitats, and dissolved oxygen. . . . Thus, phytoplankton soon reache(d) a maximum population density. . . ." Dead phytoplankton settle(d) out, resulting in heavy deposits of detritus on the lake or river bottom, which supported an "abundance of decomposers, mainly bacteria. The explosive growth of bacteria, consuming oxygen via respiration, creates an additional demand for dissolved oxygen." Suffocation of the fish resulted.
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What will be an ideal response?
Explain the eruption sequence of a typical geyser
What will be an ideal response?
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A) centimeters (inches) B) dozen centimeters (dozen inches) C) meters (feet) D) dozen meters (dozen feet) E) kilometers (miles)