Answer:
All of the above
Step-by-step explanation:
The organic matter decomposes and reduces dissolved oxygen levels making it inhabitable for the sea animals. Dissolved oxygen is the oxygenmeasured in milligrams per liter. Aquatic animals survive on a certain minimum level of dissolved oxygen, but Stagnant water contains much fresh organic matter causing the aquatic system to have insufficient amount of dissolved oxygen and therefore be unable to support life.
II. Decomposition of organic matter releases great quantities of nutrients. This causes break down of dead organic materials and release nutrients into the water by especially bacteria and fungi releasing releases great quantities of nutrients causing Eutrophications leading to the water body to overly enriched with minerals and nutrients which induce excessive growth of algae resulting in oxygen depletion which is unsafe for aquatic life. III. Pathogenic organisms are carried into surface waters.
Water is often polluted by domestic wastewater and contains a variety of pathogenic organisms, including viruses, bacteria,which is an indicator for the threat of aquatic life.