Contemporary Issues in Biology Online Course

Reporter: I am speaking with Jessica, a University of Oklahoma scientist focusing on smallmouth bass and aquatic ecosystems. She is here today because she is concerned about what humans are doing to harm smallmouth bass and other freshwater organisms. Jessica, tell us about the smallmouth bass.

Jessica: The smallmouth bass is a freshwater fish native to North America. They are very popular game fish; once caught, they put up a strong fight, which fishermen enjoy.They are mostly concentrated in eastern North America, particularly the Great Lakes region. They only grow to a maximum of 27 inches in length and 12 pounds. The smallmouth bass prefer clear, shallow water near the bottom of lakes, rivers, and streams. They do not tolerate pollution. For example, pollution can change the pH of the water; if the water is even mildly acidic, the fish cannot successfully reproduce.

Jessica: The freshwater sources are becoming more and more polluted from sewage, industrial waste, farmland runoff, soil erosion, and extremes in water level fluctuation. Many people dump their household waste into lakes, rivers, and streams; the streams run into rivers, which then run into lakes or oceans. These bodies of water become the final resting place for cans, bottles, plastics, and other household garbage. As the water becomes polluted, the smallmouth bass cannot survive because they require clean waters for breeding. If we continue to pollute the water, the smallmouth bass will suffer, as will many plants and other organisms.

Jessica: Many types of waste, including sewage and fertilizers, are rich in nutrients such as nitrates and phosphates. Water is a solvent, meaning that other chemicals (including nutrients) dissolve in it. These excess nutrients enter the freshwater, where they act as fertilizer for the plants and algae in the water. The resulting overgrowth of plants is called eutrophication. When microbes decompose the plants, they use up the dissolved oxygen that many aquatic organisms, including smallmouth bass, need to survive. Anaerobic microbes, those that do not require oxygen, are then able to attack the organic waste and releases gases, such as methane. These gases are harmful to the aerobic, or oxygen-requiring life forms. This affects the smallmouth bass and many other organisms by not providing them with enough dissolved oxygen in the water. This entire process results in a foul-smelling, polluted body of water.

Jessica: Yes! Do not ever dump your waste into any body of water, especially organic material. Also, many detergents contain phosphates that contribute to eutrophication; look for phosphate-free brands. In your yard, don't fertilize if whatever you apply might enter a stream or lake. The U.S. Environmental Protection Agency provides different ideas you can do to make a difference and how to dispose of your household waste. .

Reporter: Thank you for your time, Jessica. As you can see, water pollution destroys aquatic life and therefore affects us as well. We should all be concerned with water pollution. By simple household practices we all can help to reduce water pollution!

References:

"Acting Locally." United States Environmental Protection Agency. Posting date unknown. http://www.epa.gov/epahome/acting.htm. Download date 27 July 2006.

Contemporary Issues in Biology -- BIOL 1003
Mariëlle H. Hoefnagels, Ph.D. © 2004-2015.
biology1003 at OU dot edu (at = @, dot =.)
Last Updated August 5, 2014 11:02 PM

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Week 3, Chapter 2 -- Digging Deeper Sample Answer

References:

Contemporary Issues in Biology -- BIOL 1003 Mariëlle H. Hoefnagels, Ph.D. © 2004-2015. biology1003 at OU dot edu (at = @, dot =.) Last Updated August 5, 2014 11:02 PM

Contemporary Issues in Biology -- BIOL 1003
Mariëlle H. Hoefnagels, Ph.D. © 2004-2015.
biology1003 at OU dot edu (at = @, dot =.)
Last Updated August 5, 2014 11:02 PM