BIOLOGY LAB REPORT

TITLE : LOOKIN FOR PATTERNS IN TANJUNG BIDARA, MALACCA

PREPARED BY :

I/C NUMBER :

STUDENT ID :

GROUP :

LAB PARTNER : GOVERNMENT GROUP

LECTURERS NAME :

PRACTICAL DATE :

SUBMISSION DATE :

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Abstract

We set off from our hostel at about 7.30 am. After a two and half hour journey, we reached at our

ultimate destination, Tanjung Bidara, Malacca eventually. Then, we were divided into two groups and

we set off to find desirable place where suit our investigation the best by walking around the rocky

shore. After that, each group began to distribute work among them such as finding a suitable way of

laying out tape measure for a transect study, finding out distribution of organism along the transect

line using 0.25 m2quadrat and measuring all biotic and abiotic factors. The experiment was done

within one day and was successfully conducted. This report will discuss about the relationship

between distributions of species with abiotic factors that exist there.

Introduction

Hygrometer(1)

A hygrometer is an instrument used for measuring the moisture content in the environmental air

(humidity). Most measurement devices usually rely on measurements of some other quantity such as

temperature, pressure, mass or a mechanical or electrical change in a substance as moisture is

absorbed. From calculations based on physical principles, or especially by calibration with a reference

standard, these measured quantities can lead to a measurement of humidity. There are different types

of hygrometer, such as metal/pulp coil type, hair tension hygrometer, electronic hygrometer and more.

Metal/pulp coil hygrometer is very useful in giving a dial indication of humidity change while hair

tension hygrometer use human or animal hair under tension by calculating the length of the hair that

changes with the humidity. Besides greenhouses and industrial spaces, hygrometers are also used in

some incubators, saunas, humidors and museums. They are also used in the care of wooden musical

instruments such as guitars and violins which can be damaged by improper humidity conditions. In

residential settings, hygrometers are used to aid humidity control.

Figure 1 : Hygrometer(2)

Calculating relative humidity

1 Subtract the wet-bulb temperature from the dry-bulb temperature.

2 Find the difference in degrees at the top of the chart and place your nger on it.

3 Find the dry-bulb temperature in the rst column on the left. Place your nger on it.

4 Bring your ngers down the column and across the row. The relative humidity percentage

appears where column and row intersect on the chart.

Figure 2 : Relative humidity table(3)

Quadrat Sampling Technique(4)

In studying and estimating the population size of an organism, ecologists need to define the

geographic boundary of the organism. The quadrat sampling technique is used in the studies of plant

population and populations of immobile animals. A quadrat consists of a square or rectangular frame

made of metal or wood. Strings are used to subdivide the quadrat into smaller squares. The frame is

pegged to the ground with a few pieces of string. A fixed wood or metal quadrat can be made up to

1m. The size of the quadrat used depends on the size, distribution and density of the organisms being

studied. A number of quadrats are set up randomly throughout the area being studied. The species

present within the frame is then counted and the number recorded. The data collected from the

different sites enclosed by the quadrats are used as samples to represent the entire habitat. The quadrat

sampling technique can be used to determine the distribution of organisms in a habitat based on the

following:

a) Frequency of a species

Frequency is the number of times a particular species is found when a quadrat is thrown/placed

a certain number of times.

Percentage frequency = (number of quadrats containing species / number of quadrats

sampled) X 100%

b) Density of the species

Density is the mean number of individuals of the species per unit area. Density can only be

used to estimate the population of plants which exists as separate units. It is extremely difficult

to estimate the population of plants which reproduce vegetatively.

Density = total number of individuals of a species in all quadrats / (number of quadrats

sampled X area of each quadrat sampled)

c) Percentage coverage of the species

An indication of the area of the quadrat that is occupied by a species. Percentage coverage is

useful when it is not possible to identify separate individuals of a species.

Percentage coverage = (aerial coverage of all quadrats, m / (number of quadrats sampled X

quadrat area)) X 100%

Figure 3: Quadrat sample(5)

Transect tape meter and transect sampling(6)

A transect line can be made using a marked nylon rope or tape meter. This transect line is laid across

the area that we wish to study. The position of the transect line is very important and it depends on the

direction of the environmental gradient we wish to study. It should be thought about carefully before it

is placed. Otherwise it may be end up without clear results because the line has been wrongly placed.

A line transect is carried out by unrolling the transect line along the gradient identified. The species

touching the line may be recorded along the whole length of the line (continuous sampling).

Alternatively, the presence, or absence of species at each marked point is recorded (systematic

sampling). If the slope along the transect line is measured as well, the results can then be inserted onto

this profile.

Figure 4: Transect line made by ecologists (7)

Dissolved Oxygen Meter(8)

A dissolved oxygen meter is used to measure the amount of oxygen present in a unit volume of water.

Indication of oxygen content in water is useful for a specific application like water treatment plants,

sewage treatment works, river monitoring and

fish farming. There are various types of oxygen meter available such as Polarographic Sensor Oxygen

Meter, Galvanic Sensor Oxygen Meter and Optical Fluorescence Oxygen Meter. These oxygen meters

differ in the range and accuracy in measuring oxygen concentration in water. The typical features that

should be available with the Oxygen Meter are self calibration, event triggers, battery packs and

filters. The technical datas that a portable oxygen meter able to capture are oxygen range, resolution,

temperature, automatic air pressure compensation, automatic temperature compensation and correction

for salinity.

Figure 5: Dissolved Oxygen Meter

(9)

Ecology (10)

Ecology is the scientific study of the relations that living organism have with respect to each other and

their natural environment. Ecosystems is a biological system consisting of all the

living organisms or biotic components in a particular area and the nonliving or abiotic component with

which the organisms interact, such as air, mineral soil, water and sunlight. Key processes in

ecosystems include the capture of light energy and carbon through photosynthesis, the transfer of

carbon and energy through food webs, and the release of nutrients and carbon through decomposition.

Biodiversity affects ecosystem functioning, as do the processes of disturbance and succession.

Ecosystems provide a variety of goods and services upon which people depend; the principles

of ecosystem management suggest that rather than managing individual species, natural

resources should be managed at the level of the ecosystem.

Figure 6 : Linnaeus Hierarchy(11)

Figure 7 : Ecosystem of a pond(12)

Barnacles(13)

A barnacle is a type of arthropod that belongs to Crustacean. These barnacles tend to live in shallow

and tidal water. They have jointed legs and shells of connected overlapping plates. They glue

themselves to rocks, ships, pilings, abalones, and maybe even whales and wait for food to wash by.

The barnacle's enemies are worms, snails, sea stars, and fish like sheep head, certain shorebirds, and

oil spills. Some are parasites inside crabs or in other animals. Barnacles are a hermaphrodite; means

that they have both male and female reproductive organs and can produce both sperm and eggs.

.

Figure 8: Anatomy of Barnacles(14)

Figure 9 : Life cycle of Barnacles(15)

Objective

To study the ecology of a rocky shore habitat (marine).

To find out the major organisms present and their adaptations to the environment

To find out the effect of the main physical factors on the distribution of organisms and the

Problem Statement :

What is the relationship between the sizes of population of marine organisms occupied in particular

areas with the abiotic factors on that area?

Hypothesis

Abiotic factor affect the species population distribution at rocky shore at Tanjung Bidara.

Null Hypothesis

There is no correlation between abiotic factors with species population distribution at rocky shore of

Tanjung Bidara.

EXPERIMENT ON BIOTIC FACTOR

Experiment 1 : Investigating the distribution of organisms using quadrat sampling technique.

Variable:

Types of Variables Ways to control the variables

Manipulated Variable:

Quadrat position

Quadrats are placed along the transect line at

interval of 5 meters.

Responding Variables:

Species density and percentage coverage

Using formula , density of species is calculated :

total number of individuals of a species in all

quadrats / (number of quadrats sampled X area of

each quadrat sampled)

Using formula, percentage frequency is calculated:

(number of quadrats containing species / number

of quadrats sampled ) X 100%

Fixed Variables:

Number of Quadrats

Interval distance (m)

4 grid quadrats were used along transect line.

Quadrats were placed at interval of 5 meters along

15 meter of transect line.

Apparatus:

A quadrat measuring m X m, pen and paper.

Procedure:

1. An area that appears to be a gradual change in the species composition across the rocky shore

was spotted.

2. A transect line of 15 meter was placed along the rocky shore using transect meter.

3. The transect line was laid on the shore, from the top of the shore to the sea water. The distance

between the starting point and final point of transect line was calculated.

4. Four quadrats with the size of 0.25m2 were then placed along the transect line of 5 meter

intervals.

5. Each of the quadrats was subdivided into 25 smaller squares where each square had the area of

10cm by 10cm.

6. The number of species found in the quadrats were noted and recorded.

7. The number of individuals of each species found were counted and recorded.

8. The data obtained was used to calculate the density and the percentage coverage of the species

in each quadrat.

9. The following formulae were used to analyse the data.

Density = total number of individuals of a species in all quadrats / (number of quadrats

sampled X area of each quadrat sampled)

Percentage frequency = (number of quadrats containing species / number of quadrats

sampled) X 100%

Results:

Species Picture Scientific name

A

White Barnacles

(Perforatus bruguiere)

B

Grey Barnacles

(Nesochthamalus

intertextus)

C

Red Algae

D

Clams ( Mya arenaria)

E

Centipede

Table A: Species that were identified at experimental site and its scientific and common name

Quadrats Distance

from the

shore

Number of individual

A B C D E

1 0.0 95 1097 97 - -

2 5.0 - 401.5 356 29 -

3 10.0 0.5 6 9 14 4

4 15.0 12 56 20.7

Table 1: Number of individual for each species according to quadrat.

Quadrats Density of species

A B C D E

1 380 4388 388 - -

2 - 1606 1424 116 -

3 2 24 36 56 16

4 48 224 82.8 - -

Table 2: Density of each species according to quadrat

Table 3: Number of square occupied by each species according to quadrat

Species Number of square occupied with species

Q1 Q2 Q3 Q4

A 18 0 1 11

B 22 17 3 16

C 10 22 7 25

D 0 6 7 0

E 0 0 2 0

Table 4: Percentage frequency of each species according to quadrat

EXPERIMENT ON ABIOTIC FACTORS

Experiment 2 :

Determining water content of a soil sample

Apparatus :

Soil sample, aluminium foil, accurate balance and thermostatically controlled oven.

Procedure:

1. The aluminium foil was weighed and recorded.

2. Sample soil from first quadrat was added to the aluminium foil and it was reweighed.

3. The mass of aluminium foil was subtracted to obtain the fresh mass of soil.

4. The aluminium foil and soil was placed in a thermostatically controlled oven that was set up at

110C and left to heat until no further loss of mass observed.

5. The dish was then removed and allowed to cool. The dry mass was recorded.

6. The loss in mass of soil sample was calculated. This represents the mass of water in the soil

which can be expressed as a percentage of the fresh mass :

Percentage of soil moisture =

(loss in mass / fresh mass) X 100%

7. The steps were repeated for sample soil from second quadrat. The result was noted.

Species Percentage Frequency (%)

Q1 Q2 Q3 Q4

A 72 0 4 44

B 88 68 12 64

C 40 88 28 1

D 0 24 28 0

E 0 0 8 0

Results:

Mass

Quadrats

Fresh Mass

Dry Mass Percentage of soil

moisture (%)

Quadrat 1

Aluminium foil

= 5.28g

Aluminium foil + soil

= 114.47g

Mass of soil

= 109.19g

Aluminium foil

= 5.28g

Aluminium foil + soil

= 107.78g

Mass of soil

= 102.5g

(109.19 g 102.5 g)/

109.19 g X 100

= 6.13 %

Quadrat 2

Aluminium foil

= 5.29g

Aluminium foil + soil

= 187.16g

Mass of soil

= 181.87g

Aluminium foil

= 5.29g

Aluminium foil + soil

= 175.61g

Mass of soil

= 170.32g

(181.87 g 170.32g)/

181.87 g X 100

= 6.35 %

Table 5: Percentage of soil moisture based on fresh and dry mass of soil obtained from first and

second quadrats.

For third and fourth quadrats, no results were obtain as the experiment for both 3rd

and 4th

quadrats

were carried on the rock (absence of sand)

Experiment 3 :

Determining percentage of organic matter in a soil sample

Apparatus :

Soil sample, aluminium foil, accurate balance and thermostatically controlled oven.

Procedure:

1. The aluminium foil was weighed and recorded.

2. Sample dry soil from first quadrat (obtained from first experiment) was added to the

aluminium foil and it was reweighed.

3. The mass of aluminium foil was subtracted to obtain the dry mass of soil.

4. The aluminium foil and soil was placed in a thermostatically controlled oven and heated for

about 15 minutes to burn off all the organic matter.

5. The dish was then removed and allowed to cool. The mass was recorded.

6. The loss in mass of soil sample was calculated. The percentage of soil organic matter was

calculated using the equation :

Percentage of organic matter in soil =

(Loss in mass / dry mass) X 100%

7. The steps were repeated for dry sample soil from second quadrat. The result was noted.

Results:

Mass

Quadrats

Dry Mass

Organic Mass Percentage of organic

matter in soil (%)

Quadrat 1

Aluminium foil

= 5.28 g

Aluminium foil + soil

= 107.78 g

Mass of soil

= 102.5 g

Aluminium foil

= 5.28 g

Aluminium foil + soil

= 106.32 g

Mass of soil

= 101.04 g

(102.5 g 101.04 g)/

102.5 g X 100

= 1.42 %

Quadrat 2

Aluminium foil

= 5.29 g

Aluminium foil + soil

= 175.61 g

Mass of soil

= 170.32 g

Aluminium foil

= 5.29 g

Aluminium foil + soil

= 171.0 g

Mass of soil

= 165.71 g

(170.32 g 165.71 g)/

170.32 g X 100

= 2.71 %

Table 6: Percentage of organic matter in soil based on dry mass of soil obtained from first and second

quadrats.

For third and fourth quadrats, no results were obtain as the experiment for both 3rd

and 4th

quadrats

were carried on the rock (absence of sand)

Experiment 4 :

Determining the pH of a soil sample

Apparatus :

Soil sample, test tube, pH meter

Procedure:

1. About 2 cm of soil was placed inside the test tube. About 10 cm of distilled water was added

and the test tube was shaken thoroughly. Soil samples that were taken from sea were placed in

test tube and the contents were allowed to settle down.

2. A pH meter was dipped into the solution and value that was indicated was recorded.

Results:

Quadrats pH value

1 5.5

2 5

3 6

4 7

Table 6: pH value based on quadrats

Experiment 5 :

Determining relative humidity in the air across habitat

Apparatus :

Hygrometer, stopwatch, distilled water, relative humidity table.

Procedure:

1. About 1 cm of distilled water was filled into water component of hygrometer and it was

screwed to the instrument.

2. The hygrometer was then swirled in the air at about 20 seconds (time taken was calculated by

stopwatch) at the experimental habitat.

3. Reading were taken for dry bulb and wet bulb. Using the relative humidity table, the wet

depression was calculated.

4. Steps for reading the relative humidity table is as follow :

i. Subtract the wet-bulb temperature from the dry-bulb temperature.

ii. Find the difference in degrees at the top of the chart and place your nger on it.

iii. Find the dry-bulb temperature in the rst column on the left. Place your nger on it.

iv. Bring your ngers down the column and across the row. The relative humidity

percentage appears where column and row intersect on the chart.

5. The relative humidity of air was noted and the steps were carried out for all experimental

habitat.

Results

Quadrats Hygrometer Readings Relative humidity

Dry Bulb Wet Bulb

1 29.5 26.5 79

2 29 26 79

3 29 26 79

4 28 25 78

Table 7: Readings for relative humidity based on dry and wet bulb readings

Experiment 6:

Determining the oxygen concentration and temperature

Apparatus :

Dissolved oxygen meter, test tube, stop watch

Procedure:

1. The stand-by switch was slide to the stand position for 30 minutes and the meter was

calibrated.

2. The protective plastic cap was removed and the sensor was rinsed in distilled water.

3. The sensor was then immersed in the sea water (in test tube) and stirred.

4. The temperature reading was recorded after the F/R switch was on and (C) appears in the

display (indicating the reading has stabilized).

5. The F/C switch was pressed again (PPM will be displayed) and the dissolved oxygen reading

was taken after 1 or 2 minutes (enable reading to stabilize).

6. The steps were repeated for the fourth quadrat and the results were noted.

Results:

Quadrats Temperature (C) Oxygen content in water

Percentage (%) Parts per Million (ppm)

3 31.6 145.4 9.00

4 31.4 145.0 9.09

Table 8: Temperature and oxygen concentration that were taken in quadrats

Since first quadrat and second quadrat were done on the sandy part of the beach, thus no data obtained

for oxygen content in water due to absence of water in sand.

Safety Precaution and Risk Assessment

In order to avoid any accident or injury during the experiment which is carried out at sea shore, the

precautionary steps should be taken and applied. Wearing suitable attire and a pair of suitable shoes

are compulsory before entering the sea to protect the skin and for extra protection against sharp

barnacles onto the rock. All students required to wear life jacket to prevent them from drowning

during experiments being carried out. Furthermore, the glassware such as test tube should be handled

with full care because they are fragile. After using all apparatus at the end of experiment, they

should be returned back to their places to avoid injuries and unnecessary accidents that may result

fatal results. Care should be taken when handling the heating oven. The skin might be burn when

there is a direct contact with the heating element of the oven. Hence, gloves should be worn when

taking out the soil sample from the oven.

Discussions and Data Interpretation

This experiment was conducted to study the population size of organism in the quadrat area,

specifically, population size of species available along the rocky seashore. Tanjung Bidara was chosen

as experimental side. The manipulated variable for this experiment is the abiotic factor (pH of soil,

humidity, oxygen concentration in water, temperature of water, soil water, and soil organic matter).

Each of this abiotic factor have certain effect on the population of organisms along the transect line.

The dependant variable for this experiment is number of each species in the quadrat that is counted

and by using formula that is stated in introduction part, the density and percentage frequency of

species is calculated. These quadrats were lay down on transect line of 15 meter, with an interval of 5

meter.

The most distinct species that was found along the transect line at experiment site is white barnacles or

known as Perforatus bruguire. It is noted that in first quadrat, species A is about 95, in second quadrat

no species A is noted and in third and fourth quadrat, about 0.5 and 12 species A is calculated. Density

of species A is the highest in first quadrat (380 m) followed by the fourth quadrat (48 m) and third

quadrat (2 m) and lastly with no density of species A in second quadrat. Percentage coverage of

species A also seen to be highest in first quadrat with 77% followed by the same trend, fourth

quadrat,44% and third quadrat,4% .Overall, species A is the third highest species in both density and

percentage frequency along the transect line. The abundance of this species can be said due to the

conducive and suitable environment which is moist and enable the species to reproduce. Since species

A have special ability to withstand higher salinity of sea water, thus it contribute to advantage for it to

reproduce and survive.

For species B, grey barnacles or its scientific name, Nesochthamalus intertextus, the abundance of this

species is found to be the highest among the other. Species B is noted present in all quadrat , highest in

the first quadrat with 1097 individuals and 4388m of density , followed by the second quadrat (401.5

individuals and 1606 m of density), fourth quadrat(56 individuals and 224 m of density) and lastly

the third quadrat(6 individuals and 24 m of density). Their percentage frequency is 232 % which is

the highest among all species that was included in this experiment. Grey barnacles are small in size but

having strong protection layer enable them to survive in harsh condition of sea environment, thus they

reproduce in large number. Since quadrat 3 and 4 are on the rock (submerged in water), thus reduction

in protection for survival cause lesser species B individuals in these two quadrats.

Since lesser species A found in the quadrats, thus this may indicate that lesser interspecific

competition between species A and B happened than intraspecific competition among species B.

Intraspecific competition is more intense because the needs of the individuals of species B for

nutrients, food and other things are identical. Since all needs are almost available in quadrats thus,

enables the species B to reproduce in larger number.

As for species C which is red algae, the number of individual calculated was the highest in second

quadrat (356) and the lowest in third quadrat(9). The algae covered the whole fourth quadrat as the

fourth quadrat was placed on a fully submerged in sea water. Algae have the second highest

percentage frequency (157%) among all species. Algae found to present in all quadrats. Since all the

experimental sites were done near the sea shore and in the sea, thus this provide suitable and

condusive place for the algae growth, resulting in growth of algae in all quadrats.

For species D, which is clams (Mya arenaria), they were only found in second and third quadrats with

about 24% and 28% percentage frequency. These clams were found out by burrowing the sand. Direct

illumination on the exposed sea shore can produce extremely high temperature and this may result in

fatal destruction towards the species. These clams were found to close their shells in order to prevent

predator attack and to reduce desiccation.

As for species E(centipede), it is the lowest species that lives in this extreme condition and

environment under the barnacles. Centipedes are only found in third quadrat with only four in number,

barely having 1% of percentage frequency. It is noted that the barnacles provide protection for the

centipedes from predators. No advantages for the barnacles were noted because of the presence of

centipedes. It can be concluded that commensalism has taken place.

For abiotic factors, humidity (ranged from 78 to 79), oxygen concentration in water (ranged from 9.00

to 9.09ppm) and temperature (ranged from 31.4 to 31.6) are only slightly varies for each of the four

different position quadrat thus, concluded not play major role in species distribution at this area. pH of

soil noted to become neutral from acidic towards sea although the first quadrat shows higher acidity

than the second quadrat. This may be due to some limitation or error during the measurement taken.

Improvements can be made by taking more than one sample (about three samples) at different quadrats

position to calculate average pH value at each quadrat. This can increase the validity and reliability of

the data.

For water content in soil, it can be seen that soil from quadrat 2 (6.35%) contain higher water content

than quadrat 1(6.13%). This is because quadrat 2 is nearer to the sea than the first quadrat by 5 meters.

Percentage of organic matter in soil found to be the highest in quadrat 2 (2.71%) than quadrat

1(1.42%).

In conclusion, we can see that both biotic and abiotic factors are interdependent on each other and

have link between them.

Limitations

There are several limitations that have been identified throughout this experiment.

Since the third and fourth experimental area was carried out on the rock, the quadrats were

unable to lie down properly. The rocky area is also sharp and slippery (due to algae presence)

causing the quadrat to be placed unevenly and even slipped sometimes.

The humidity and temperature calculated is affected by the duration of the day. During the

experiment was carried out, the humidity may be high, which in turn indicate the low

temperature due to the rainy condition. Other than that, temperature and humidity may vary

depending on the time when the reading taken (early in the morning or in the evening).

Since it is a group work, different student estimate percentage coverage in different quadrats

that introduce personal variation which lead to less accurate results.

Sources of errors

Several sources of error in this experiment were identified and steps were taken to minimize these

errors to make the result more accurate.

During calculation of individual species of an area in particular quadrat, a lot of barnacles with

smaller sizes present. This, tend to make students to calculate, make assumption and estimation

on the number of individual species, especially the minute one.

During the process of taking the sea water, there might be some impurities or even organisms

that mixed with sea water sample. This leads to less accurate result of pH value.

Reading of hygrometer may be misread due to parallax error (eyes are not perpendicular to the

meniscus of the bulb) and glance by high intensity of sunlight when taking the reading of

hygrometer. This leads to decrease in precision and reliability of data.

Rate of spinning the hygrometer should be same (not differ by too fast or too slow) as this will

affect the result. This error is minimized by using same student every time when humidity of

air was calculated. The humidity and temperature also taken for each of the area of quadrat

involved so that any link or relationship of the humidity and temperature on the distribution of

species can found out in detail. Whirling hygrometer should be placed in the same position

each time a measurement is carried out to increase the validity of data.

Hygrometers also need to be calibrated in air before used every time. A further difficulty is that

most hygrometers sense relative humidity rather than the absolute amount of water present, but

relative humidity is a function of temperature and absolute moisture content, so small

temperature variations within the air in a test chamber will translate into relative humidity

variations, leading to inaccuracy of data.

During calculation of number of different species, students might wrongly identify a species

thus made the result less accurate. Sometimes, we might miss some of the organisms inside the

area of the quadrat for they might hide under some sharp barnacles which are very dangerous

to remove away. Centipedes move very fast during counting and this poses difficulty again.

Conclusion

Based on the experiments, it can be concluded that population density of species can be calculated

using quadrat sampling technique. Thus, the hypothesis is accepted. The size of population of different

species that has been found in Tanjung Bidara varies depending on abiotic factors that influence on the

location of the quadrat placed.

Further Investigation

Another experiment can be carried out by carry out the same experiment in a forest. Quadrat sampling

technique can be used to find out the number of percentage of different species in the forest. Other

abiotic factors such as composition of soil by sedimentation method can be carried out to find abiotic

factor that influence growth of different species in different places.

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