vce biology 1/2-"effects of ph on brine shrimp survival rates"

EFFECTS OF PH ON BRINE SHRIMP MORTALITY RATE

INTRODUCTION◦ Brine Shrimp are a genus of aquatic Crustaceans (Exoskeletal animals).◦Natural Habitat: Great Salt Lake, streams and Inland rivers. Ecological Niche

capable protection from predators.◦ Salinity Tolerance: 25‰ to 250‰ (25–250 g/L)◦Diet: Planktonic Algae ◦ Recommended Breeding PH 8-9 (Basic) ◦ Popular organism used for toxicity testing of◦ Effects of environmental pollutants on ecosystem.

Experimental MethodAim of the experiment: To test the survival rates of adult brine shrimp brine shrimp in various Ph levels Hypothesis:Higher pH level, decreases survival rate How the experiment was conducted?Materials used:

6 clear test tubes 36 adult brine shrimpAcetic Acid (vinegar) Base (sodium bicarbonate)Universal indicator pH indicator chart

Ruler, marker, stopwatch Measuring cylinder Test tube rack Water

RESULTS

EXPERIMENTAL SET UP

DISCUSSION Data◦General downward trend for shrimp survival rates as PH deviated away from 7 ◦ Results were as expected, Hypothesis accepted, number of surviving shrimp decreased

as pH deviated from 7, this can be proved by comparing the varying pH to control (Brine Shrimp Water)

◦ Applications: Mortality of shrimp in pH can be applied to the effects of pollutants on ecosystems

Limitations: ◦Data does not apply to different species of Brine Shrimp which may have different

tolerance levels.◦ Range of pH

DISCUSSION ◦ Experimental Errors: ◦ Systematic Errors-volume of water was not constant due to inaccuracy of measuring cylinder and test

tubes. ◦ Random Errors- Varying levels of stress due to shrimp being placed individually. ◦ Small amounts of Brine Shrimp Water contamination with test tube water, affecting true PH of Water. ◦ Accuracy of timing ◦ Marking of water levels may not have been consistent ◦ Universal Indicator ◦ Anomalies- The mortality rate of the control did not remain constant at 50 minutes, one shrimp may have

died as a result of stress during transport.

Improvements◦ Marking of water levels◦ Method of placing shrimp-Stress levels◦ Range of pH used.

CONCLUSION ◦ Brine Shrimp survived for longer in a pH of 8 than any other. This correlates to

evidence from previous studies which showed the optimum hatching pH of Brine Shrimp was 8-9

◦ " "Generally, an increase in acidity will decrease the hatching rate" " (Westminster College 2016)

◦ Significance: This data can be applied to Brine Shrimp Hatcheries and the pH of the hatching environment.

◦Hypothesis was supported by data. ◦ Aimed was achieved◦ Brine Shrimp Hatchery (Right)

ReferencesBritannica.com, H.S. (2016). Encyclopedia Britannica. Retrieved 25 May, 2016, from http://www.britannica.com/animal/crustacean/images-videosIn-text citation: (Britannica, 2016)

Wikipedia.org. (2016). Wikipediaorg. Retrieved 25 May, 2016, from https://en.wikipedia.org/wiki/Brine_shrimpIn-text citation: (Wikipedia.org, 2016)

Uscedu, P.S.G. (2016). Uscedu. Retrieved 25 May, 2016, from https://www.usc.edu/CSSF/History/2012/Projects/J1107.pdfIn-text citation: (Uscedu, 2016)Westminster college, S.L. (2016). Westministercollege.edu Retrieved 25 May, 2016, from https://www.google.com.au/url?sa=tIn-text citation: (Westminster college, 2016)