Soap Runoff Effects on Algal Populations Mike Trentadue 2008 PJAS Central Catholic

Ground Runoff o Ground runoff is part of the water cycle and is when water runs across land formations. o It is caused when rain and excess water start to flow down hill. o During Ground Runoff the water can carry many pollutants such as…

Pollutants  Pesticides  Fertilizer  Litter  Oil and Gasoline Spills  Soap

Soaps  Soaps are a mixture of chemicals to form a cleaning agent that can be used to clean various surfaces.  There are various types of soap including Antibacterial and Non Antibacterial.  The active ingredient in the soaps to kill bacterial is Triclosan.

Algae  There are many different kinds of algae through out the world.  One of the most common being Euglena.

Euglena  Euglena is a common group of freshwater single celled organisms in the Kingdom Protista.  There are about 150 species of Euglena.  They produce their own food through photosynthesis.

Triclosan  Triclosan has been shown to be effective in reducing and controlling bacterial contamination on the hands.  Research has also show that the presence of Triclosan may influence the structure and function of algal communities in stream ecosystems.

Purpose  The purpose of this study is to find out what kind of effect soap runoff would have on the growth of Euglena in our aquatic ecosystems.

My Hypotheses  Null: The growth rate of the algae contaminated with the higher concentrations of soap WILL NOT exceed the growth rate of the algae with the lower soap concentrations.  Alternate: The growth rate of the algae contaminated with higher concentrations of soap WILL exceed the growth rate of algae contaminated with the lower concentrations of soap.

Materials  Test Tubes- 16  Spring Water  Euglena – 34ml  Test Tube Racks – 4  Spectrophotometer – 1  200µl micro-pipette -1  10ml macro-pipette -1  5ml macro-pipette – 1  Palmolive Antibacterial Dish Soap – 1 Bottle  Palmolive Non-Antibacterial Dish Soap – 1 Bottle  4 Styrofoam Cups

Procedure  First, stock solutions of each of the soaps with 1 part soap and 9 parts water were mixed.  Next the test tubes were made to make 1% soap, 0.1% soap and 0% soap with the following combinations.

Tubes 0% AB0.1% AB 1% AB0% Non-AB.01% Non- AB 1% Non- AB Spring Water 3 (ml) Euglena 2 (ml)22222 Soap Concentration 0 (ml) Total 5 (ml)55555 * AB = Antibacterial *Repeat Table 4 Times

Procedure (continued)  After filling the tubes as shown they were placed in a test tube rack the racks were placed under a window which received sufficient morning light.  Next, Spectrophotometer readings were taken every day for 10 days at around 9 pm.

Day Absorbance in 430 nm Soap Effects on Algal Populations

Percent Absorbance Change Per Soap Concentration (Days 1-10) % Change in Absorbance Soap Concentrations P=.018 P=.002 P=9.943 E-05 P=.034

Limitations  Algae may not of been very healthy at the start of the experiment.  The experiment could have been repeated more times to have more examples to test the hypothesis.  The experiment could have been run for longer than 10 days.

Extensions  To further test the hypothesis…  Algae that is know to be healthy could be used.  The experiment could be tested more times.  Collect data over a longer time span to test long term effects.  A larger variety of soaps could be used to show their own effects.  A variety of other algae species could be used to show other effects.

Conclusions  The hypothesis that stated the growth rate of the algae contaminated with the higher concentrations of soap WILL NOT exceed the growth rate of the algae with the lower soap concentrations was REJECTED.  The null hypothesis was rejected because the p values were < (less then).05.

Conclusions (continued)  The hypothesis that stated the growth rate of the algae contaminated with higher concentrations of soap WILL exceed the growth rate of algae contaminated with the lower concentrations of soap was ACCEPTED.  The alternate hypothesis was accepted because the null hypothesis was rejected due the to the p value being < (less than).05.

References