Answer:
I believe it would be D
Step-by-step explanation:
Why is temperature, pH, and dissolved oxygen
important to water quality?
Temperature – Temperature affects aquatic organisms in a variety of
ways. The body temperature of most aquatic organisms is the same as
the surrounding water and fluctuates with the water temperature.
Most aquatic organisms are adapted to live in a narrow temperature
range and they die when the temperature becomes too low or too
high. Temperature affects their metabolism, reproduction and
emergence. Temperature also affects the rate of photosynthesis of
aquatic plants, the base of the aquatic food web. Pollutants can
become more toxic at higher temperatures. The amount of dissolved
oxygen becomes lower as the water becomes warmer. Temperature is
measured in degrees Fahrenheit or Celsius (Centigrade).
pH – pH is the measure of hydrogen ions, or acidity, in the water.
Water has hydrogen ions and hydroxyl ions. When there are equal
numbers of both, the water is neutral. As the hydrogen ions increase,
the water becomes more acidic; as the hydroxyl ions increase, the
water becomes more basic. pH is measured on a logarithmic scale of
0 – 14: 7 is neutral; below 7 is acidic; above 7 is basic. Most aquatic
organisms have a narrow pH tolerance range of 6.5 – 8.5. Acidic
waters can cause toxic heavy metals to be released into the water.
Acid rain and mining operations can lower the pH of water bodies.
Dissolved Oxygen – Most aquatic organisms need oxygen to survive.
Dissolved oxygen is the oxygen present in water available to aquatic
organisms. It is not the oxygen that is part of the water molecule but
rather oxygen gas. Oxygen enters the water from the air through rain,
turbulence and wind, and through the photosynthesis of aquatic
plants. Organisms absorb the oxygen through structures such as gills
or their skin. Waters with higher dissolved oxygen have ecosystems
that are generally more diverse and stable. Decomposition of organic
material is a major cause of low dissolved oxygen resulting in fewer
species. Dissolved oxygen is measured in parts per million (ppm) or
milligrams per liter (mg/L).