East Coast Beach Research and Reflection

Research:

- Water Pollution

Hypothesis:

- The seawater at East Coast is polluted and is acidic.

What we need to find out:

- The clarity of the seawater

- Whether the seawater is acidic or alkaline

- Type of dirt particles or rubbish in the seawater

- Photographs evidence of polluted water

Methodology:

1. Walk along East Coast Beach and identify 4 points along the sea with different activities going on.

2. Collect a sample (1 bottle) of seawater from each sample.

3. Label point A, B, C or D on the bottles.

4. POur out 2 beakers of 50cm3 of seawater from each sample

5. Observe the clarity of the seawater and smell it. Record down observations.

6. Pour out some seawater from each sample into different test tubes.

7. Dip red and blue litmus paper into the seawater in each test tube then record observations.

8. Drop pH paper into the test tube and record the pH.

9. Filter one of the 2 beakers of seawater from each sample then boil it in an evaporating dish until the salt is left. Record observations and time.

10. With the other beaker left, boil it straight in an evaporating dish without filtering, until the salt is left. Record observations ad time.

11. Compare the results for the different samples.

Findings:

Bottle A - breakwall (camping, a lot of ships, more people and activity)

Bottle B - control (no human activities, more birds. No rubbish on shore)

Bottle C - left side of jetty (jetty fishing, water is black(ish), a lot of rubbish, washed-up seaweed, strong waves)

Bottle D - right side of jetty (no rubbish, smaller waves)

Smell:

Bottle A - no smell

Bottle B - no smell

Bottle C - strong fishy smell

Bottle D - mild fishy smell

Clarity: (1) clearest ------ (4) least clear

Bottle A: (3)

Bottle B: (4)

Bottle C: (2)

Bottle D: (1)

pH paper test:

Bottle A: turned blue (pH 8-9) (1st test tube)

Bottle B: turned blue (pH 8-9) (2nd test tube)

Bottle C: turned blue (pH 8-9) (3rd test tube)

Bottle D: turned blue (pH 8-9) (4th test tube)

Litmus paper test:

Bottle A (top left hand corner): turned red litmus paper slightly blue. Blue litmus paper remains blue.

Bottle B (bottom left hand corner): turned red litmus paper slightly blue. Blue litmus paper remains blue.

Bottle C (top right hand corner): turned red litmus paper slightly blue. Blue litmus paper remains blue.

Bottle D (bottom right hand corner): turned red litmus paper slightly blue. Blue litmus paper remains blue.

Residue (dirt) for filtered seawater: (1) most residue ----- (4) least residue

Bottle A: (1)

Bottle B: (2)

Bottle C: (3)

Bottle D: (4)

Residue (salt) for filtered seawater: (1) most residue ---- (4) least residue

Bottle A: (3)

Bottle B: (2)

Bottle C: (1)

Bottle D: (4)

Residue (salt) for unfiltered seawater: (1) most residue ----- (4) least residue

Bottle A: (3)

Bottle B: (2)

Bottle C: (4)

Bottle D: (1)

Observations during the boiling of the water (filtered):

Bottle A: A lot of effervescence is produced.

Bottle B: A lot of effervescence is produced.

Bottle C: Little effervescence is produced.

Bottle D: A lot of effervescence is produced.

Observations during the boiling of the water (unfiltered):

Bottle A: A lot of effervescence is produced.

Bottle B: A lot of effervescence is produced.

Bottle C: Hardly any effervescence is produced.

Bottle D: A lot of effervescence is produced.

Time taken for the water to evaporate (filtered):

Bottle A: 11.55 minutes

Bottle B: 10.57 minutes

Bottle C: 13.09 minutes

Bottle D: 12.33 minutes

Time taken for the water to evaporate (unfiltered):

Bottle A: 15.11 minutes

Bottle B: 12.58 minutes

Bottle C: 18.50 minutes

Bottle D: 10.54 minutes

Conclusion:

Based on the time the unfiltered water took to boil, the water from Bottle C is the most polluted as it took the longest time for the water to evaporate. Also, when the water was evaporating, there was hardly any effervescence at all. This shows that the water in Bottle C could be more chemically polluted than physically polluted.

As the water in the other bottles were being evaporated, a lot of effervescence was produced. Hence, the water in Bottles A, B, and D were more physically polluted as compared to the water in Bottle C.

According to the pH paper test, the seawater that we collected is alkaline instead of acidic. Also, the seawater is polluted because of the photo evidences that the rocks and breakwalls have eroded.

The water in Bottle A is the most physically polluted as there was the most amount of dirt found on the filter paper. Thus, it proves that the human activity occurring at Point A (where we got the water in Bottle A from) is affecting the cleanliness of the water.

Reflection:

Through the research, I found out that seawater is actually alkaline instead of acidic.

This can be proven in the photos of the breakwalls. There is algae growing on the bottom of it, where it is in constant contact with the waves. This is because there are phosphates and nitrates present in the seawater, which causes it to turn alkaline and promote algae growth. As the beach receives daylight every day, the light also fuels the algae growth.

Also, I learnt that the activities that were carried out near the shore can also affect the cleanliness of the water.

At Point C, there were people fishing on the sand (near the jetty) and on the jetty. The water collected from Point C smelled fishy and it was very dirty. Some parts of the water was black and there was rubbish floating in the water as well as lying on the shore. There were also tons of washed-up seaweed. As the unfiltered seawater collected from Point C took the longest to evaporate, it was the most polluted water among the 4 samples that we collected. Also, due to the large amounts of rubbish found in the water, the water could be chemically polluted as well as physically polluted.

Whereas for the other points where we collected the water, the water was not as polluted as the water from Point C. This is because there was lesser human activity being carried out.

At Point A, even though there were people camping, the water was not that polluted as the people camped on the ground. Hence, they did not really affect the water cleanliness. However, they might have affected the cleanliness of the land around that area. The rubbish found in the sand could be washed into the sea when the tide is high, thus polluting the water.

Therefore, from this research and "field trip", I learned about the cleanliness and the alkalinity of the seawater at East Coast Beach.

~Kimberley Lim~