Measuring Toxicity in Aquatic Ecosystems | Measuring Toxicity in Aquatic Ecosystems

Introduction

Brine Shrimp (Artemia salina) are a part of the class Crustacea, (crabs, lobster, shrimp), and they are in the phylum Anthropoda, (joint-legged). Brine shrimp are only 10 millimeters long but are very important organisms in the hyper saline lakes (salt water lakes, like Great Salt Lake) ecosystems. Brine Shrimp survive by eating microscopic organisms that live in the lake. Brine shrimp are always in motion because they are filter feeders and use their appendages to funnel their food towards their mouths, algae and bacteria are the main prey for Brine Shrimp. They are not only an important piece of the food web but they also assist in the clean up of contaminants such as phosphorous, nitrogen and other household waste products.

Purpose

The purpose of this experiment was to find out if Brine Shrimp could survive in water with toxic waste (Fantastic, Simple Green, and Vinegar) in it. The reason we are testing to see if Brine Shrimp can survive in water with toxic waste in it is because we are constantly polluting the waters that Brine Shrimp live in and we need to know how we are effecting the Brine Shrimp.

Hypothesis

If a treatment of more than 10% vinegar is added to the Brine Shrimp, then the Brine Shrimp will all die.

Materials

*Brine Shrimp *Petri dish

*Vinegar *Simple Green

*Fantastic *Water

*Watch * Graduated Cylinder

Procedure

To start this lab I had to first collect the materials I needed to conduct this lab, I got a Petri dish of Brine Shrimp, water, Fantastic, a Graduated Cylinder, and a watch. First I counted how many of the Brine Shrimp there were alive in my Petri dish. Then I got a Graduated Cylinder and made a solution of Fantastic and water so that the solution was 10% Fantastic. I poured it into the Petri dish of Brine Shrimp and I timed ten minutes on my watch, and then recorded how many Brine Shrimp were still living. After I had my data I recorded it onto my data table, and cleaned up. The independent variable in this experiment was the concentration of Fantastic in the Brine Shrimps water. The dependent variable in this experiment was the percent mortality of the Brine Shrimp. The constants in this experiment were the: water temperature, total amount of solution, type of Brine Shrimp, size of Petri dishes, and time allowed for Brine Shrimp to die. The control of this experiment was 0% Fantastic in the water.

Data/Results:

Simple Green

% Solution 0% 1% 5% 10% 20%

Exp #1

% Mortality 0 0 0 0 17.8

Exp #2

% Mortality 0 0 5.3 24 9.5

Average

% Mortality 0 0 2.65 12 13.65

Fantastic

% Solution 0% 1% 5% 10% 20%

Exp #1

% Mortality 0 0 0 18.3 12.5

Exp #2

% Mortality 0 0 40.6 3 12.5

Average

% Mortality 0 0 20.3 10.75 12.5

Vinegar

% Solution 0% 1% 5% 10% 20%

Exp #1

% Mortality 12.2 31 14 36 5

Exp #2

% Mortality 0 24 0 8 36

Average

% Mortality 6.1 21.6 7 22 20.5

Discussion

I think that the results of this experiment were not very accurate, For example Two of the classes had a 0% mortality rate in the 0% concentration levels and the last class had a 6.1% mortality rate in the 0% concentration level. I also found it a little concerning when there was over a 20% mortality rate in the 5% solution level and only a 12.5% mortality rate in the 20% solution level. In all three of the different experiments there was one % concentration level with an unordinary high mortality rate, it could be either human error or just bad luck with the Brine Shrimp. But without these anomalies there is a solid conclusion that we can come to. The data shows us (without the anomalies) that the higher the % concentration of Fantastic, Simple Green, and Vinegar that there is a higher mortality rate.

Conclusion

I feel that overall this experiment went well, the results were sufficient enough to come to some solid conclusions about Brine Shrimp and their ability to survive in toxic waters. I think that just the nature of this experiment, working with such small animals, and such a large number of them really set you up for making mistakes. Perhaps that is why there were some results that did not seem to be quite right. My hypothesis was not correct; in fact the Brine Shrimp died in solutions under 10% concentration, when I said they would only die if the % concentration was over 10.