Amphetamine

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Name

Trophic Level

Quantity

Vallisneria (Algae)

Producer

1

Duckweed

Producer

-

Aquatic Snail

Primary Consumer

1

Shrimp

Primary Consumer

2

Worm

Primary Consumer

2

Table 1: Living organisms used in the “ecosystem in the bottle” experiment

[pic 2]

Figure 2.1. Ecosystem setup

Abiotic factors were taken for measurements every week during four weeks of the experiment for healthy monitoring of the ecosystem. Length and water level were measured by using a ruler and weight using a balance. Temperature, the concentration of dissolved oxygen, pH, salinity, were measured by a multimeter and nutrients levels (nitrate and phosphate) was measured by using the indicator testing kit. Biotic components were measured at the beginning and end of the experiment, included the primary consumers, producers length and weight. Alongside with biotic and abiotic factors measurements, observations on survival proportion of primary consumers and water colour were also taken. The ecosystems then stored in the glasshouse and covered by the net on top of the jar after all the measurements were made. After four weeks of the experiment, data was obtained and gathered in table results, abiotic components results were then graphed and given explanations through extrapolation by applying basic biological concepts such as the flow of energy, decomposed and photosynthesis process.

After completing the experiment, the deconstruction process of the ecosystem was taken place. An aquatic snail and shrimps were placed into a first container. Secondly, water was poured out from the jar into the sink, a sift was used to separate duckweeds and worms. Then duckweeds, Vallisneria were put into another container, sediment and rock were finally left inside the jar.

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Results

3.1 Abiotic components

Over the four-week-experiment, pH levels slightly increased from 7.1 in week one, follow by 7.5 and 7.8 in week two and week three then dramatically rised to 9.6 by week four (Figure 3.1.1).

[pic 3]

Figure 3.1.1 The change of pH levels in experimental aquatic ecosystem

The concentration of Oxygen was highest in week four at 14.36 (mg/L) and lowest in week three at 8.77 (mg/L). Overall, the Oxygen levels fluctuated throughout four weeks, slightly decreased from week one to week three and significantly increased in week four, the final week (Figure 3.1.2)

[pic 4]

Figure 3.1.2 The change of Oxygen levels in experimental aquatic ecosystem

There was an inconsiderably rising in salinity levels of the aquatic ecosystem during the four-week of the experiment, 254 (uS/cm) in week one, follow by 293 (uS/cm) and 317 (uS/cm) in week two and three then increased to 320 by week 4 (Figure 3.1.3).

[pic 5]

Figure 3.1.3 The change in Salinity levels in experimental aquatic ecosystem

The highest temperature recorded was in week four at 24.9 (oC) and the lowest temperature was marked at week two with 17.5 (oC). Water temperature decreased from week one and week two then started increasing from week two to week four (Figure 3.1.4).

[pic 6]

Figure 3.1.4 The change in water temperature in experimental aquatic ecosystem

Phosphate level reached the highest peak at 1 (mg/L) then dramatically dropped down to 0.25 (mg/L) in week three and increased to 0.5 (mg/L) by week four. However, there was no detection of Nitrate levels during the experimental aquatic ecosystem (Figure 3.1.5).

[pic 7]

Figure 3.1.5 The change in Nitrate and Phosphate levels in experimental aquatic ecosystem

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Biotic components

Table 3 shows specific measurements of primary consumers and producers length and weight during the first week and the last week of the experiment. It was found that the length of Vallisneria had increased but was not remarkable while its weight was decreasing. The weight of other primary consumers and producers which are Snail, Shrimps and Duckweed were inconsistently recorded. Unfortunately, worms were too small and active for the measurements to be made.

Week

Vallisneria (g)

Vallisneria (cm)

Vallisneria (Number of leaves)

Duckweed (g)

Weight of Snail (g)

Length of Snail (cm)

Length of Shrimps (cm)

1

52.19

46

8

-

1.7

1.83

2.2

4

46.50

17 (broken)

20

5.3

1.78

1.85

2.4

Table 3. Week

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