C - Brine Shrimps (Environmental Pollution)

Investigation into the Water Quality of Various River Systems using Brine Shrimp as an Indicator

Jeremy Sim, Tan You Yi, Chiu Chen Ning, Chai Ning, Charlene Leong

School of Science and Technology, Singapore

Abstract

Felda Region, Johor State, Malaysia is home to various fish farms that export their produce to all corners of Malaysian markets. However, their water supply to cultivate their fishes is reliant on seasonal rains that are unpredictable. Thus their water supply is unstable which puts the income of the farmers and their families at risk of poverty. We propose to utilize brine shrimp, which shares many optimal growth conditions with saltwater fish, to determine the suitability of the various rivers in the region for saltwater fish farming. Thus, the farmers can expand their range of farmable fish to include saltwater fish in addition to freshwater fish, improving their income security for them and their families.

1. Introduction

1.1 Research Questions 


What environmental conditions are optimal for brine shrimp growth?

How do varying water parameters affect the survivability of brine shrimp?

What is the minimum number of shrimps required to indicate water quality?

What are the important water parameters to test for in our experiment?

      1.2 Hypothesis

River C will exhibit the highest brine shrimp survivability rate, as abundant saltwater life is found in its waters. Since brine shrimp require saltwater to grow and live, River C’s water will be most suitable for brine shrimp survival.

Figure 1: An image of River C, showing abundant saltwater life.

River A will exhibit the lowest brine shrimp survivability rate, as its waters are murky and thus low in oxygen levels, leading to the brine shrimp dying due to lack of oxygen in the water.

Figure 2: An image of River A, showing murky waters.

2. Methods

2.1 Equipment List

Item Name	Quantity
1.8 litre container	1
Brine Shrimp Egg Packets	1
Air Pump	1
Sea Salt	35 g
Tap Water	1 litre
Stirrer	1
Microscope	1
Petri Dish	6
Glass Slide	6
Cover Slip	6
Dropper	6
Water Samples (A, B, C)	200 millilitres x 6 (2 per site)
250ml Beaker	6
Measuring Cylinder	1

2.2 Diagrams of experimental setup 

Figure 3: A picture of the brine shrimp hatching process. Air is being bubbled into the salt water to keep the brine shrimps alive and promote their hatching.

2.3 Procedures

      1.     Fill the 1.8 litre container with the tap water.
2.     Add the sea salt and mix well.
3.     Set up the air pump such that the tube is bubbling into the water.
4.     Add the brine shrimp eggs and mix well.
5.     Leave the set-up under indirect light at 25-30°C for 24 to 36 hours, until the eggs have hatched.
6.     Obtain the water samples from the 3 designated sites into the beakers.
7.     Label the petri dishes ‘A: 1’, ‘A: 2’, ‘B: 1’, ‘B: 2’, ‘C: 1’ and ‘C: 2’.
8.     Use the measuring cylinder to transfer 20ml of each sample into their respective petri dishes.
9.     Use the droppers to transfer 5ml of brine shrimp solution into each petri dish.
10.  Leave the petri dishes under indirect light at 25-30°C for 3 hours.
11.  Use the droppers to transfer 1ml of each solution onto the glass slides. Cover each slide with a cover slip.
12.  Observe each slide under a microscope. Ensure that at least 10 brine shrimps are on each slide.
13.  Calculate the number of brine shrimps living over the total number of brine shrimps on each slide.
14.  Plot values in an appropriate table and draw conclusions.

2.4 Risk Assessment and Management 

Risks Assessment:

-       Shrimps spill out, causing death of shrimps

-        Water spills out and this causes us to slip and fall

-        glass slides might break and we might cut our hands and bleed

-        we may get electrocuted due to handling water near electrical sources

Risk Management:

-        keep shrimps covered in a tight container with uv light and bubbling source so that shrimps do not spill or die

-        wear rubber gloves and goggles when handling glass objects

-        do not handle water near electrical points

2.5 Data Analysis

In order to determine whether the water source is suitable for saltwater fish to live in, we will use brine shrimp survivability as a gauge for the water sample’s suitability. The survivability rate is calculated like this:

Number of alive shrimp / Total number of shrimp (at least 10)

The survivability rate ranges from zero to one. As it approaches zero, a less percentage of shrimps are able to survive in the water sample, meaning that the respective river water is more unsuitable for saltwater fish rearing. As it approaches one, a greater percentage of shrimps are able to survive in the water sample, meaning that the respective river water is more suitable for saltwater fish rearing.

3. Results

The results of our experiment are as shown below:

Table 1: Table of shrimp survival rate for the different water samples

Water Sample Location	Number of Alive Shrimps			Total Number of Shrimps	Shrimp Survival Rate
	Reading 1	Reading 2	Average Reading
River A	3	4	3.5	10	0.35
River B	5	4	4.5	10	0.45
River C	9	8	8.5	10	0.85

Figure 4: A dead brine shrimp from a water sample of River B.

Figure 5: An alive brine shrimp from a water sample of River C.

Figure 6: A dean brine shrimp from a water sample of River A.

4. Discussion

4.1 Key Findings & Analysis of results

After observation of the brine shrimp under a microscope, we have obtained readings of the number of brine shrimps alive against the total number of brine shrimp (10 for each sample).

We have found that the average survivability rate of brine shrimp in River A is 0.35 (3.5 of 10 brine shrimp survived), the lowest value of the three rivers.

We have found that the average survivability rate of brine shrimp in River B is 0.45 (4.5 of 10 brine shrimp survived), the intermediate value of the three rivers.

We have found that the average survivability rate of brine shrimp in River A is 0.85 (8.5 of 10 brine shrimp survived), the highest value of the three rivers.

4.2 Explanation of key findings

River A had the least survivability of the three rivers, showing that more factors were not present for the growth of the shrimp. We suspect it to be the water being murky and the river water being fresh. The murky water contained less oxygen, resulting in the shrimp dying due to lack of oxygen in the water for respiration. Since brine shrimp thrive in salt water of high salinity, River A’s water could have had too low salinity for the shrimp, causing the shrimp to die off. River B had an intermediate of the three rivers, showing that less factors were not present for the growth of the shrimp, or the factors were of less intensity. We suspect it to be the water being clear but the river water still being fresh. The clear water contained more oxygen, resulting in the shrimp able to respire within the water. Since brine shrimp thrive in salt water of high salinity, River B’s water could have had too low salinity for the shrimp, causing the shrimp to die off. River C had the greatest of the three rivers, showing that the factors were favorable for the growth of the shrimp. We suspect it to be the water being clear and the river water being salty. The water contained more oxygen, resulting in the shrimp able to respire within the water. Since brine shrimp thrive in salt water of high salinity, River B’s water could have had a high enough salinity for the shrimp, causing the shrimp to thrive.

4.3 Evaluation of Hypothesis

Our results correlate strongly with our planned hypothesis. River A indeed had the lowest survivability rate of the three rivers, and we suspect it to be because of the water being fresh and murky. River C indeed had the highest survivability rate of the three rivers, and we suspect it to be because of the water being salty and clear. Thus, River C is the best for rearing of saltwater fish, as the brine shrimp with similar water requirements as saltwater fish could thrive in them.

4.4 Areas for improvement

           1. Take greater care when handling live specimens, especially when transporting them from one place to another.
         2.  A better microscope so that we can analyze our data more efficiently and save time.
         3.  Bring more relevant equipment when experiment is done on-site.

5. Conclusions

5.1 Practical Applications

Using our data collected, we can increase the growth of saltwater fish (eg Scortum baracoo) in organic farms by locating the organic farms near the rivers, which has the highest percentage of living shrimps. Allowing farmers to be able to recognize the rivers that contain less chemicals, therefore tapping into these rivers for their fish supply. Thus this results in the area having a greater economical and social benefit for those living in that area.

5.2 Areas for further study

We can research more into the organic fish farm that we are aiding; to find out what species of fishes they grow.

We can then find out what type of water best suits each of these species. These allow farmers to be able to be more focused in their field of farming so that they can gain better yields of fishes. Moreover, they do not need to spend time finding the factors because we can provide the data for them based on observations and testing, as well as find suppliers or ways to make more benefit out of their yield.

We can also research about the methods to treat water originating from polluted sources.

Based on the picture, we realise that there is a village population that live in the farms and these places are far from sea or their water sources (which is near the sea.) Hence, since they are nearer to the river, they can spend less time travelling or maintaining pipes if they have an easier access to water from the rivers.