Chloride Salt Effects on Algal Populations And the Dangers that they Present By:Brandon Perrotte Grade 9 Central Catholic 2008

Introduction Chloride salts have potentially harmful effects on algae. These salts enter the ecosystem due to runoff. It has been found that they can be corrosive and harmful to the environment. The chloride salts, when used cause the decrease in population of thousands of organisms, especially algae. This could therefore affect the organisms that feed off of the algae and could then disrupt the environment.

Background Information: Chloride Salts Chloride Salts are binary compounds of chlorine. They can be corrosive and are soluble in water. The salts used in the experiment were sodium, magnesium and calcium chloride. Some solid chlorides can be decomposed through the process of hydrolysis.

Environmental Effects and Inhibitions of Chloride Salts We use sodium chloride, or common road salt, to clear the ice from our streets to prevent accidents and injury. This act also induces runoff into small marine and wildlife ecosystems. The runoff may contain salts and other potentially harmful chemicals. This could be harmful to thousands of small organisms and their habitat. It might also produce some toxicity effects to the water that we drink and use for common practices such as brushing our teeth and showering daily.

Past Studies of Chloride Levels in Streams Minnesota passed laws restricting salt use for its disruptive corrosion and for the reduction of water pollution

Discriminative Algal Traits Euglena It is a common protist. It is commonly cylindrical in shape. The chloroplasts in euglena are clear. They are used as a common aspect of many algal investigations. They are found in freshwater bodies such as ponds most commonly during warm seasons. The algae can function without sunlight by taking nutrients from decomposed organisms. Chlamydomonas Chlamydomonas are unicellular flagellates. The ion channels such as channelrhodopsin are activated by light. They are found in small freshwater bodies. This algae is a common model for many algal experiments.

Purpose The Purpose of this experiment was to investigate the effects of chloride salt concentrations on two different algal populations.

Hypothesis Null- The tested algal populations exposed to chloride salts will not vary significantly in growth from the controls. Alternate- The tested algal populations exposed to chloride salts will vary significantly in growth from the controls.

Materials and Methods Materials Borosilicate test tubes(72) Spectrophotometer(1) Fluorescent lamp(1) A large container of spring water 2 containers of both euglena and chlamydomonas. 5ml pipette 200 microliter pipette Three containers of 10% stocks of sodium chloride, magnesium chloride, and calcium chloride micron syringe filter 15 mL sterile polystyrene conical tubes Test Tube Racks(2) One Sharpie marker Micropipette and pipette tips General Experimentation Six sets of test tubes were filled with different concentrations of water, algae, and a variable. They were placed in a test tube rack and were given light by an overhanging fluorescent lamp. A spectrophotometer was used to measure absorbance (and indirect measure of population size) and set at a wavelength of 430 nm.

Procedure x100mm borosilicate culture tubes were placed in both test tube racks tubes were placed into each row. 3.Algae, spring water, and one of three chloride salts were pipetted into the experimental tubes as follows to create the desired salt concentrations.

Procedure (Continued….) 4. The tubes in the racks were exposed to light by a fluorescent lamp. The light from the lamp evaporated a portion of the solution. The water was replaced carefully to keep a correct volume. 5. After mixing tubes by inversion, the absorbance at 430 nm was recorded on days 1, 3, 6, 9, 12 and 15.

Procedure (continued…) 0%1%4% Algae2mL Spring Water3mL2.5mL1mL Salts0mL.5mL2mL Total Amount5mL

ANOVA Two Factor with Replication (Euglena) ANOVA Source of VariationSSdfMSFP-valueF crit Sample Columns Interaction Within Total

ANOVA Two Factor with Replication (Chlamydomonas) ANOVA Source of VariationSSdfMSFP-valueF crit Sample Columns Interaction Within Total

Conclusion The chloride salts had a negative long term effect on both algal populations. This may have been due to the corrosive properties of the salts or it may have been just the concentration of the salt that killed the algae.

Conclusion (continued…) These results show that algal populations in the environment are at a great risk of decreasing in size because of the potential misuse of chloride salts. The communities at the greatest risks are the ones near roadsides where road salts are being used to clear ice for safety. This effects many environmental organisms and ultimately the ecosystem that the algae make up.

Conclusion (continued…) It is concluded in this experiment that the decrease in the algal populations was due to growth inhibition caused by chloride salts. The Results drawn from the ANOVA data analysis showed p- values greater than.05 so the null hypothesis was rejected. (An ANOVA was performed on the absorbance results of both euglena and chlamydomonas.) The Dunnett Test was also used to conclude results. The information was drawn by a t-test in which the resulting critical values were below the approved critical values of Dunnett’s Test. The critical value was above.05 therefore the null hypothesis was rejected.

Limitations and Extensions There were only four trials for each treatment. Use more tubes to increase experiment length. Use different concentrations to increase the diversity of results. Use a wider variety of chloride salts and algae. The right amount of light was not precise as it was not known how the algae would operate under different amounts of light. Therefore light was used at a random amount.

References “Chalmydomonas Reinhardtii.” Wikipedia.org. 12 Jan “Euglena.” Wikipedia.org. 12 Jan “Road Salt Harmful to Roadside Vegetation.” DailyTargum.com. 12 Jan /news/2000/02/08/News/Road- Salt.Harmful.To.Roadside.Vegetation shtml “Road Salt: Can we have safe roads and healthy streams?” DuluthStreams.org. 12 Jan

References (cont.) Dr. John Wilson, biostatistician, University of Pittsburgh Sudhir, P. and Murthy, S.D.S. “Effects of salt stress on basic processes of photosynthesis.” 22 Jan Batterton Jr. John C. and Van Baalen C. “Growth responses of blue-green algae to sodium chloride concentration.” 22 Jan