Chapter 56: Q1CC (page 1258)

How can the addition of excess mineral nutrients to a lake threaten its fish population?

Short Answer

Expert verified

A higher amount of mineral nutrients in water systems (such as lakes) will increase the numbers of algae population and their growth rate. Excess algae population in the lakes will reduce the dissolved oxygen level under the lake.

Fishes use the dissolved oxygen from the water, so low oxygen levels can destroy the fish ecosystem and other aquatic animals such as oysters and crabs.

Step by step solution

Definition of minerals

Minerals are inorganic elements that are homogeneous solid with internal structures.Minerals are formed naturally and have specific physical properties. Examples of minerals are amphibole, feldspar, olivine, and others.

Algal growth

Low levels of oxygen will increase algal growth. The primary reason for the increased production of algae is the presence of phosphorous. Algae are decomposable, and due to this decomposition process of algae, the requirement of dissolved oxygen is vital.

Effects on fish population

In water resources, dissolved oxygen will regulate the levels of both nitrogen and phosphate. Most aquatic organisms will require dissolved oxygen for preparing their foods. Also, a low amount of oxygen will push the fishes into shallow waters.

The survival rate for the fishes will decrease,and fishes will die in the absence of enough oxygen levels required for their respiration process. Fishes will not be able to produce energy.

From the water, fishes can absorb dissolved oxygen directly. The dissolved oxygen will reach the bloodstream through their gills instead of the lungs.