Complete Fish Project

Fisheries Science Project 2005 Ibarahim Haleem MV404

SSOOCCIIOO –– EECCOONNOOMMIICC SSUURRVVEEYY

AAIIMM:

To study the socio economic status of fishermen in Baa Eydhafushi.

MMAATTEERRIIAALLSS RREEQQUUIIRREEDD::

A standard questioner

Graph paper

PPRROOCCEEDDUURREE:

A sample of fishermen was selected at random from population

of 225. The sample included Angler, Chummer, Captain and Owner.

The fishermen were interviewed on the basis of the questioner. They

were interviewed in the local language. The information collected was

pooled and analyzed.

- 1 -


• Table showing data collected by survey.

Serial Number

Age

No. of Children

Weekly income

Profession

No. of Dhoani

Rank

1. 40 4 1000 Fishing _ Angler 2. 56 9 1000 Fishing _ Captain 3. 48 6 700 Fishing 1 Angler 4. 42 4 600 Fishing _ Angler 5. 39 7 750 Fishing _ Chummer6. 43 5 700 Fishing _ Chummer7. 44 6 900 Fishing 1 Captain 8. 38 7 2000 Fishing _ Captain 9 65 5 1000 Fishing _ Captain 10 41 7 1000 Fishing _ Angler 11 45 7 1000 Fishing _ Angler 12 30 - 2200 Fishing 1 Captain 13 35 3 1000 Fishing _ Captain 14 45 6 1000 Fishing _ Captain 15 46 7 800 Fishing _ Angler 16 35 3 1000 Fishing 1 Captain 17 63 5 1200 Fishing _ Captain 18 35 8 1050 Fishing _ Captain 19 40 5 1000 Fishing _ Angler 20 44 8 1500 Fishing _ Angler 21 44 3 1000 Fishing _ Angler 22 43 5 2500 Fishing 1 Owner 23 40 5 1000 Fishing _ Angler 24 50 6 600 Fishing _ Angler 25 85 10 3000 Fishing 2 Owner 26 40 7 1000 Fishing _ Captain 27 41 6 900 Fishing _ Angler

- 2 -


• Frequency table showing age group of fishermen.

AGE GROUP FREQUENCY PERCENTAGE

20 - 30 0 0%

30 - 40 6 22%

40 - 50 16 59%

50 - 60 1 4%

60 - 70 3 11%

70 - 80 0 0%

80 - 90 1 4%

27 100

- 3 -


Bar graph showing age group of fishermen

0

10

20

30

40

50

60

7020

- 30

30 -

40

40 -

50

50 -

60

60 -

70

70 -

80

80 -

90

Age group

Percentage

- 4 -


Pie chart showing Age group

50-60

60-70

20-3080-90

70-80

30-40

40-50

- 5 -


• Table showing Average weekly income

RANK WEEKLY INCOME (MRF)

Chummer 725

Angler 925

Captain 1214

Owner 2750

- 6 -


Bar graph showing average weekly income

0

500

1000

1500

2000

2500

3000

Chummer Angler Captain Owner

Rank

Weekly income ( In MRF )

- 7 -


Pie chart showing average weekly Income

owner

Chummer

Angler

Captain

- 8 -


• Table showing weekly socio – economic status

RANK WEEKLY INCOME (MRF)

Chummer 725

Angler 925

Captain 1214

Owner 2750

Secretary 560

Supervisor 760

Assistant Principal 1260

Atoll Chief 1620

- 9 -


Bar graph showing weekly socio - economic status

0

500

1000

1500

2000

2500

3000

Chu

mm

er

Angle

r

Cap

tain

Ow

ner

Secr

etar

y

Supe

rviso

r

Assis

tant

Prin

ciple

Atol

l Chi

ef

Rank

Weekly income (MRF)

- 10 -


Pie chart showing Socio Economic weekly status

ChummerAngler

Captain

OwnerSecretary

Supervisor

Assistant Principle

Atoll Chief

- 11 -


CCOONNCCLLUUSSIIOONN::

It was found that the older people in between the age group

40-50 took up fishing. The younger generation has taken up jobs in

tourism industry instead of fishing. The average weekly income graph

shows that the boat owners are the person who is making maximum

profit through fishing.

From the data collected, it was found that the majority of the

fishermen interviewed were Angler and Captain.

The weekly income table of fishermen class shows that the boat

owners are earning the highest income, where as chummers is the

people who are drawing the lowest income.

The weekly income table of other professionalists shows that

the Aoll chief is the person who is drawing the highest salary. Secretary

is the person who is drawing the lowest salary.

The comparison of fishermen’s salary with that of the other

professionalists indicates that the boat owners are the people who are

earning maximum income among the group followed by Atoll chief.

This is followed by Captain and Assistant principal who are drawing

RF1214 and RF 1260 respectively. From the table it was also found

that chummers and supervisor are drawing equal amount of income of

RF 725 and RF 760 respectively.

- 12 -


TTWWOO DDIIFFFFEERREENNTT EENNVVIIRROONNMMEENNTTSS

AAIIMM::

To compare the external features of pelagic and demarsal

fish.


A pelagic fish (skipjack tuna)

A reef fish (Emperor)

PPRROOCCEEDDUURREE::

Place the two fishes on a wooden board. The

following body features were compared and studied.

Body shape

Fins

- Caudal fin

- Pectoral fin

- Dorsal and anal fin

- Fin lets

Scales

- 13 -


Gills

Muscles

Bones

OOBBSSEERRVVAATTIIOONN:

FEATURES PELAGIC FISH DEMARSAL

FISH

Body shape Streamlined Deep bodied

Fins

- Caudal

- Pectoral

- Dorsal and anal

Crescent

Long and pointed

Short and

retractable

Square

Short and broad

Long and

continues

Gills Larger gill area Smaller

Scales Reduced Large scales

Muscles More red muscles Less red muscles

Bones Thin and light Thick and hard

- 14 -



• Pelagic fish (Tuna)

The Pelagic fish tuna are fast and continues

swimmers, which are found in open sea. They are migratory

in nature.

Tuna swims fast because its body is streamlined.

Tuna have long and pointed pectoral fin, retractable dorsal

and anal fin and reduced scales. Bones are light and thin.

Tuna needs higher energy because it swims for longer

distance.

It has more red muscles and which provide higher

amount of energy and larger gill area, which provides more

oxygen.

• Reef fish (Emperor fish)

It is seen in the reef where there are foods.

The adaptation of reef fish is for short burst swimming

and is clear from its morphological features (external). It

has:

Long dorsal and anal fin

Short and broad pectoral fin.

Body shape - Deep bodied. - 15 -


More white muscles for short burst swimming.

PELAGIC FISH (TUNA)

- 16 -


REEF FISH (EMPEROR)

- 17 -


- 18 -


EESSTTIIMMAATTIIOONN OOFF SSAALLTTNNEESSSS OOFF

SSEEAAWWAATTEERR

AAIIMM::

To estimate the saltiness of seawater.


A liter of seawater

A measuring cylinder

A weighing balance

A beaker

Heat source


Salinity is the total amount of dissolved salts in seawater. We

took a measuring cylinder and measured 1 liter of a sample of seawater.

It was heated on a heat source until all the water evaporated. After a

few minutes when all the water got evaporated, only the salts were

remaining at the bottom. The beaker was allowed to cool down and

using a weighing balance the mass of the salts determined. The

experimented repeated three times and the average value was taken as

the salinity of the seawater sample.

- 18 -


OOBBSSEERRVVAATTIIOONN::

Sample

Volume of seawater

(In mm)

Weight of salt

(In grams)

Average

1 1000 33

2 1000 34

3 1000 33

33.33 g


In the present study we found that the average salinity of the

seawater sample was 33.33 grams. This value is less than the salinity of

open sea. This might be due to rainfall and the subsequent dilution.

- 19 -


IIDDEENNTTIIFFIICCAATTIIOONN OOFF CCOORRAALLSS

IINNTTRROODDUUCCTTIIOONN::

A visit was undertaken within this island. The main objective of this

visit was to study about the different reef zones and the organisms

found in each zones and classification of those organisms. Another

objective was to study about the different corals, which are found in

different reef zones. The relationship existing between different

organisms and different types of adaptations found in these organisms

were observed and recorded.

- 20 -


RREEEEFF ZZOONNAATTIIOONNSS::

The different reef zones identified were as follows.

• Slash zones:

It is the area where the water is thrown up at the beach by the

waves.

• Littoral zone

It is the area between the high and low water level.

• Lagoon

Shallow water near the beach is called a lagoon. This area has

very little water movement. So there is less mixing with open sea.

The temperature, salinity and nutrients are less in this area.

• Reef flat

Area between lagoon and reef front is called reef flat. The wave

action is low in this area. The reef front protects this area from the

strong waves and currents.

- 21 -


•• DDIIAAGGRRAAMM OOFF RREEEEFF ZZOONNAATTIIOONN

Island (finolhu) giri faru lagoon reef flat inner thila reef reef front Inner reef slope

- 22 -


TTYYPPEESS OOFF CCOORRAALLSS OOBBSSEERRVVEEDD::

The five main types of corals, which were observed during the study,

are as follows.

Coral type Habitat Environmental condition

Branching corals Reef flat Movement of water less

Brain corals Reef flat Movement of water less

Mushroom corals Reef flat Movement of water less

Table corals Reef flat and slope Movement of water less

Massive corals Reef front Movement of water less

DDIIAAGGRRAAMMSS OOFF DDIIFFFFEERREENNTT TTYYPPEESS OOFF CCOORRAALLSS::

Brain coral Mushroom coral Branching coral

Massive coral Table coral

- 23 -


DDIIFFFFEERREENNTT TTYYPPEESS OOFF CCOORRAALLSS OOBBSSEERRVVEEDD::

In general it was observed that there were only few corals

growing in the lagoon. In the reef flat and reef front massive corals and

brain corals were the most common forms. Branching corals were also

present but most of them were dead. There were also dead patches of

massive corals and brain corals in the reef front. In areas of good corals

growth there were abundant coral reef fishes. They included surgeon

fishes, butterfly fishes and parrot fishes. These fishes were less

abundant in areas of dead corals. Coralline algae were also seen in

these areas.

In the reefs, organisms live in association with other species. The

different types of associations that were recorded were commensalisms

and mutualism.

- 24 -


CCoommmmeennssaalliissmmss

Shark and remora live in association with each other. The remoras

do not harm sharks, and as it is attached to the shark, remora fish gets

free swimming. So it gets food without wasting much energy.

MMuuttuuaalliissmm

Clown fish and sea anemone live in association with each other. Sea

anemone protects clown fish.

- 25 -


TTHHEE DDIIFFFFEERREENNTT OORRGGAANNIISSHHSS OOBBSSEERRVVEEDD IINN EEAACCHH ZZOONNEE::

SSppllaasshh zzoonnee

The different organisms found in this zone are crabs, hermit crabs

Hermit crab Hermit crab

LLaaggoooonn

The different organisms found in the lagoon are pipefish, gobies,

flat fish, sea urchin and sea cucumber

Pipe fish Goby

Sea urchin

- 26 -


RReeeeff ffllaatt

FISHES

Butterfly Clown fish Boxfish

MOLLUSCS’

Octopus Squid Murex

CORALS OTHERS

Branching corals Sponges Anemone

- 27 -


RReeeeff ffrroonntt

FISH

Surgeon fish Butterfly fish Parrot fish

MOLLUSCS’ CORALS

Giant clam Massive coral

OTHERS

Christmas tree worm

- 28 -


CCOONNCCUULLUUSSIIOONN::

Different groups of organisms were found in different reef zones.

Some of the organisms were common in various zones. The coral type

also varied in different zones. The lagoon had a poor coral growth. This

can be due to high water temperature and salinity and lack of substrate

for the settlement coral larvae.

A large-scale mortality of corals was observed in the study. This

can be due to El-Nino effect. The subsequent warm water current might

have caused the temperature of water to rise. This would have caused

the large-scale mortality of corals.

The different organisms contributed in one way or another for

buildings of the reefs. The parrotfish and coralline algae was the major

contributed sand formation. The sea cucumber played a significant role

cleaning of the environment.

The study was not carried out in the reef slope due to safety

reasons. During the study precaution was taken to wear protective

footwears.

- 29 -


TTHHEE DDIIFFFFEERREENNTT AADDAAPPTTAATTIIOONNSS OOBBSSEERREEVVEEDD::

The reef organisms also exhibit a number of adaptations. These

include structural, behavioral and functional adaptations.

11.. SSTTRRUUCCTTUURRAALL AADDAAPPTTAATTIIOONNSS

The different structural adaptations observed are as follows.

SSUURRGGEEOONN FFIISSHH::

The sharp scalpel blade like structure was need for offence and

defense.

BBOOXX FFIISSHH::

It had a hard body covering which provides protection.

- 30 -


TTRRIIGGEERR FFIISSHH::

Its first dorsal spine was used to lock itself in the coral cavity so that

the predator cannot press it out.

22.. FFUUNNCCTTIIOONNAALL AADDAAPPTTAATTIIOONNSS::

The different functional adaptations observed were as follows:

CCLLOOWWNN FFIISSHH::

The mucus covering on its body was similar to the mucus of sea

anemone.

- 31 -


OOCCTTOOPPUUSS::

It could swim fast, thus escape from its predator and change its

colour.

SSEEAA UURRCCHHIINN::

It has poisonous spines for its defense.

- 32 -


JJEELLLLYY FFIISSHH::

It has stinging cells for defense

LLIIOONN FFIISSHH::

It has poisonous spines on its body.

- 33 -


SSTTIINNGG RRAAYY::

It has poisonous sting for both defense and attack.

GGOOAATT FFIISSHH::

It has barbels, which help the fish to search for food.

- 34 -


BBUUTTTTEERRFFLLYY FFIISSHH::

It has a tubular mouth to collect food particles between the corals

and crevices.

CCLLEEAANNEERR WWRRAASSSSEE::

It feed on small fishes.

- 35 -


GGIIAANNTT CCLLAAMM::

It closes its shell when disturbs.

33.. BBEEHHAAVVIIOORRAALL AADDAAPPTTAATTIIOONNSS::

The different behavioral adaptations observed are as follows.

CCHHRRIISSTTMMUUSS TTRREEEE WWOORRMM::

It borrows itself into big corals and leave in this borrows.

- 36 -


PPIIPPEE FFIISSHH::

Its long and thin body resembles the long and thin filaments weeds

where they found.

- 37 -


FFOOOODD TTEESSTT

AAIIMM::

• To test the given sample for the presence of food groups.

• To realize the value of food in human diet.


Test tubes

Food samples (potato, egg, butter)

Glucose

Sodium hydroxide

Copper sulphate

Ethyl Alcohol

Benedict’s solution

Iodine solution

Water

- 48 -



Test tube. 1 - Test the presence of starch

Potato sample was used for the test. Add few drops of iodine

solution to the cut surface of the potato and change in coloration was

observed.

Test tube. 2 – Test the presence of lipids (fats)

Butter sample was used for the test. Take small quantity of butter in

a test tube; add about 10ml of ethyl alcohol. The mixture was shaken

well so that the lipid from the butter got dissolved in alcohol. The

colour changed was observed.

Test tube. 3 – Test the presence of reducing sugar (glucose)

Glucose solution was used for the test. Take small quantity of

glucose in a test tube and dissolve it in 10ml of water. Then add 5ml of

benedict’s solution. Heat the test tube under burner. The colour change

was observed.

Test tube. 4 – Test the presence of proteins.

Egg white was used for the study. Take small quantity of egg white

in a solution and add about 5ml of sodium hydroxide. Add few drops of

copper sulphate solution along with the sides of the test tube. The

change in colour was observed.

- 49 -



SAMPLE OBSERVTION INFERENCE

Test tube. 1 - Solution turns blue black

colour.

- Presence of starch

confirmed.

Test tube. 2 - Cloudy, white solution - Presence of lipid

confirmed.

Test tube. 3 - Solution turns red brown

colour

- Presence of sugar

confirmed

Test tube. 4 - Solution turns red brown

colour

- Presence of protein

confirmed

- 50 -



Food test is the sample method to detect the presence of food type

in a given food sample. All the tests showed positive result in the

present study.

In the case of starch test, a blue-black colour change indicated the

presence of starch in protein.

In the case of lipids when the sample was shaken which ethyl

alcohol, a cloudy white solution was obtained which confirms the

presence of starch.

In the case of sugar test the presence of reddish brown colour

confirms the presence of proteins in egg white.

A balance diet with all the food types in the right amount would

ensure a healthy body.

- 51 -


PPLLAANNKKTTOONNOOLLOOGGYY

AAIIMM::

To study the collection and observation of planktons.


Plankton net

Bottle

Microscope

Alcohol

PPRROOCCEEDDUURREE:

Collection of planktons was done in the evening around 6:30 pm.

The details of the plankton net are as follows.

Length of the net = 85 cm.

Width of the mouth = 30 cm.

The plankton net was lowered into the water and towed for

sometime. The plankton collected was transferred into a jar which

contained alcohol. The sample was observed under a microscope. The

different phytoplankton and zooplankton samples were also drawn.

- 44 -


PPHHYYTTOOPPLLAANNKKTTOONN

- 45 -


PPHHYYTTOOPPLLAANNKKTTOONNSS::

They are a large group of one-cell plants that live close to the

surface of water and provide food. These plants must keep them selves

in the lighted part of the sea. For this they have long spines and oil

droplets, which prevent them from smoking.

DIAGRAMS OF SOME PHYTOPLANKTONS:

- 46 -


ZZOOOOPPLLAANNKKTTOONN

- 47 -


ZZOOOOPPLLAANNKKTTOONN::

Some characteristics of certain zooplanktons found in the sea are as follows.

Comb jelly

Comb jelly is also called Hormiphora. Hormiphora has a pear

snaped body of about 5-20 mm in diameter. Their body is biradially

symmetrical with transparent gelatimous body possessing ciliary plates

in 8 rows. They feed on small marine animals including the eggs and

larvae of molluscs, crustaceans and fishes.

Annelid worms

Body is triploblastic, symmetrical, elongated and vermiform. The

body consists of many number of divisions, each division is called

segments. Outer covering of the body is by cuticle secreted by the

underlying epidermis. Excretion is by paired nephridia.

- 48 -


Sea star larva

The side lobes increase in length to become long, slender and

ciliated larva arms. The larva arms move and contract. The bases of

these arms surround the elevated, adhesive, glanchular, area performing

the functions of a sucker of fixation disc by which larvae becomes

attached at the time of metamorphosis.

Nauplius larva

It is egg snaped, unsegmented. It has three paired appendages.

There is a median eye, which is the characteristics of nauplius larva.

The median eye may degenerate or persist in adult crustacean. The

appendages are uniramous antennules having two groups of sensory

cells forming fruntal organs, a pair of biramous mandibles for

swimming.

- 49 -


Cyprid larva

Cypris larva is covered by a bivalved shell having addnetor

muscles. Head has compound eyes, antennules and antennae. Thorax

has six pairs biramous limbs. There is an abdomen of four segments.

Copepod

Head is well developed. Circulatory system is of open type. True

nephoridia absent but coelcomducts act as gonaducts and often has

excretory organs. Muscles are striped and separate. Thick cuticle

prevents loss of water. Comb is replaced by haremocoele.

- 50 -


Snail Larva

Body unsegmented, asymmetrical typically with a univalve.

Spirally coiled shell. Head is distinct bearing, tentacles eyes and mouth.

Foot is ventral, broad, flat and muscular. Respiration is by gills.

Circulatory system is open and the heart is enclosed in pericardium.

Excretory organs consist of metanephridia.

Arrow worm

They are active predators and few millimeters in length.

- 51 -


Jelly fish

They have true medusa which is large, bell or umbrella shape

without true velum. Marginal sense organs are tentaculocysts.

Gastrovascular system without stomodaeum. Masogloea is cellular.

Gonads are endodermal.

- 52 -


CCOONNCCLLUUTTIIOONN::

Different kinds of planktons were observed during the study. The

phytoplankton was slightly greenish in colour. This is due to the

presence of chlorophyll in them. Zooplanktons were slightly brownish.

The most common types of zooplankton were copepods.

- 53 -


DDEETTEERRMMIINNAATTIIOONN OOFF FFRREESSHHNNEESSSS OOFF FFIISSHH

BBYY OORRGGAANNOO LLEEPPTTIICC AANNAALLYYSSIISS

AAIIMM::

To determine the whether the given fish sample is spoilt or not by

organoleptic analysis.


A spoilt fish

A fresh fish

2 trays

Forceps

Scalpel

Scissors


Two samples of fish were used for the study one is freshly caught

and refrigerated where as the other is kept overnight at room

temperature (i.e.: the temperature accelerated the rate of deterioration

hence spoilage).

The fishes were kept on different trays and the observations were

made as mentioned in the table.

- 52 -


DDIIAAGGRRAAMM SSHHOOWWIINNGG AARREEAASS OOFF AA FFIISSHH WWHHIICCHH AARREE

SSUUSSCCEEPPTTIIBBLLEE TTOO SSPPOOIILLAAGGEE::

- 53 -



FEATURES FRESH FISH SPOILT FISH

1. Smell Sea weedy and fresh Bad ammonical

2.Abdomen Firm Soft

3.Sides Firm Soft

4.Mucus Clear Brownish

5.Eye Clear and firm Opaque and sunken

6.Gills Bright red Brownish

CCOONNCCLLUUSSIIOONN

The organoleptic analysis distinguishes a fresh fish from a spoilt

one. This method is very easy and inexpensive for a common man to

select good quality fish when he goes purchase fish.

- 54 -


DDIIAAGGRRAAMM SSHHOOWWIINNGG AA GGOOOODD QQUUAALLIITTYY FFIISSHH::

DDIIAAGGRRAAMM SSHHOOWWIINNGG AA PPOOOORR QQUUAALLIITTYY FFIISSHH::

- 55 -


DDEETTEERRMMIINNAATTIIOONN OOFF SSPPOOIILLAAGGEE IINN FFIISSHH

BBYY CCHHEEMMIICCAALL MMEETTHHOODD

AAIIMM::

To determine whether a given fish sample is spoilt or not by using

simple chemical method.


A fresh fish

A spoilt fish

Two test tubes

Dilute sodium hydroxide

Dilute hydrochloric acid

Glass rod

Burner


The two test tubes are labeled as A and B. In test tube A

fresh fish sample was taken and in test tube B spoilt fish was taken.

Sodium hydroxide was added to both the test tubes and heated using

a burner. The glass rod was dipped in hydrochloric acid and showed

in the mouth of the test tubes and the observations were recorded.

Repeated the experiment for getting confirmation.

- 56 -



TEST RESULT CONFIRMATION

Sample A add sodium

hydroxide

No fumes Sample is fresh

Sample B add sodium

hydroxide

White fumes Sample is spoilt.


Ammonia is released when the fish begins to spoil. In test tube

A the sample was fresh. Hence there was no ammonia to react with

hydrochloric acid to produce fumes. Where as in test tube B where

we placed spoilt sample, the ammonia present was reacted with

hydrochloric acid and formed white fumes of ammonium chloride.

- 57 -


MMEEAASSUURRIINNGG CCUURRRREENNTT

AIM:

To measure the speed of currents in the lagoon.

MATERIALS:

A plastic bottle

A plastic or nylon twine (20m)

Stop watch

Compass.

PROCEDURE:

Suitable 10 areas were selected in the lagoon having about hip deep

water. A plastic or nylon wire was tied to the bottle on its neck. It

was filled with sand for 1/4th of its capacity. The lid of the plastic

bottle was closed tightly and then released in the lagoon. The bottle

was allowed to sink to 1/4th of its size.

It drifted away with the currents, without being obstructed by

corals or any other materials. When the bottle moved to 20m

distances time taken by the bottle to move away and direction was

noted.

- 58 -



• Table showing the results of the measuring current around Eydhafushi.

Loc Date Time Bottle Time Distance Speed Average Direction (starting) (secs) (m) (m/s) Speed B1 330 20 0.06 NE B2 315 20 0.06 0.07 NE 1 25-5-2002 12:00pm B3 315 20 0.06 (High Tide) NE B4 240 20 0.08 NE B5 265 20 0.08 NE

B1 439 20 0.05 NE B2 611 20 0.03 0.05 NE 2 26-5-2002 5:00pm B3 472 20 0.04 (Low Tide) NE B4 476 20 0.04 NE B5 306 20 0.07 E B1 96 20 0.21 N B2 85 20 0.24 0.2 NE 3 27-5-2002 3:35pm B3 125 20 0.16 (Low Tide) NE B4 110 20 0.18 NE B5 104 20 0.19 NE B1 487 20 0.04 NW B2 316 20 0.06 0.05 NW 4 27-5-2002 5:05pm B3 345 20 0.06 (Low Tide) N B4 372 20 0.05 NE B5 478 20 0.04 NE B1 407 20 0.05 N B2 390 20 0.05 0.07 N 5 28-5-2002 4:30pm B3 255 20 0.08 (Low Tide) N B4 220 20 0.09 N B5 252 20 0.08 N B1 152 20 0.13 NW B2 226 20 0.09 0.13 NW 6 28-5-2002 5:15pm B3 119 20 0.17 (Low Tide) N B4 160 20 0.13 N B5 135 20 0.15 N B1 180 20 0.11 NE B2 314 20 0.06 0.08 NE 7 28-5-2002 5:35pm B3 410 20 0.05 (Low Tide) NE

B4 233 20 0.09 NE B5 227 20 0.09 NE

B1 148 20 0.14 E B2 109 20 0.18 0.18 SE 8 28-5-2002 4:40pm B3 98 20 0.2 (Low Tide) E B4 102 20 0.2 E

- 59 -


B5 126 20 0.16 NE B1 112 20 0.19 N B2 120 20 0.17 0.17 N 9 28-5-2002 5:00pm B3 160 20 0.13 (Low Tide) N B4 136 20 0.15 N B5 145 20 0.14 N

B1 161 20 0.12 NE B2 151 20 0.13 0.13 NE

10 28-5-2002 5:20pm B3 137 20 0.15 (Low Tide) NE B4 140 20 0.14 NE B5 184 20 0.11 NE

- 60 -


LINE GRAPH SHOWING AVERAGE SPEED IN DIFFERENT LOCATIONS

0

0.05

0.1

0.15

0.2

0.25

1 2 3 4 5 6 7 8 9 10

Location

Average speed

- 61 -



A flow current was observed from the outer location 5. The

current from location 1 flows towards east and followed coastal line

of the island up to location 5, where the current flows into open sea.

The current flows from location 6 towards location 10, from where it

finally flows in to open sea. The current flows from location 8

through location 9 to location 10 towards the north direction where

it flows in to open sea.

The current in the location 3 was found to be maximum.

- 62 -


MOVEMENTS OF CURRENT AROUND EYDHAFUSHI

N

KEY:

Current Direction

W E

High tide L5

Low Tide

S

L4

L2

L3

L1

L6 L10

L7 L9 L8

- 63 -


PPOOPPUULLAATTIIOONN SSAAMMPPLLIINNGG

AAIIMM::

1) To measure the mean length and weight of a sample of fishes

2) To study the standard deviation of the sample.

MMAATTEERRIIAALLSS RREEQQUURREEDD::

20 members of scads (Mushimas)

Weighing balance

Measuring board.


20 members of scads were selected from a group of random. The

fishes were caught by pole and line method.

Length was measured using a measuring board. Mass was found

using a weighing balance.

Sum of individual length Average length = Total number of fishes 321.6 = 20 = 16.08 cm

Sum of individual length Average weight = Total number of fishes 1223 = 20 = 61.15 cm

- 64 -


• Table showing the length and weight of scads.

Serial number

Length (cm)

Weight (grams)

1 16.2 65

2 17.2 80

3 15.4 56

4 15.7 57

5 15.6 54

6 16.3 62

7 17.1 74

8 15.7 73

9 16 60

10 16 63

11 15.8 58

12 16.2 62

13 16.3 65

14 15.8 55

15 16.3 64

16 15.1 50

17 16.4 64

18 16.3 57

19 15.4 55

20 16.8 69

321.6 1223

- 65 -


• Bar graph

BAR GRAPH SHOWI NG LENGTH AND WEI GHT OF SCADS

0

10

20

30

40

50

60

70

80

90

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Number of scads

Length and weight

Length

Weigth

- 66 -


• able showing length group frequency.

SIZE- GROUP FREQUNCY PERCENTAGE

T

(cm)

15 - 15.5 3 15

15.5 - 16 5 25

16 - 16.5 9 45

16.5 - 17 1 5

17 - 17.5 2 10

20 100

- 67 -


BAR GRAPH SHOWI NG LENGTH GROUP FREQUENCY

05

1015

20253035404550

15 -

15.5

15.5

- 16

16 -

16.5

16.5

- 17

17 -

17.5

LENGTH

PER

CEN

TAG

- 68 -


Table showing weight group frequency.

SIZE-GROUP

(gm)

FREQUENCY PERCENTAGE

•

50 - 55 3 15

55 - 60 6 30

60 - 65 6 30

65 - 70 3 15

70 - 75 1 5

75 - 80 1 5

20 100

- 69 -


BAR GRAPH SHOWI NG WEI GHT GROUP FREQUENCY

0

5

10

15

20

25

30

3550 - 55

55 - 60

60 - 65

65 - 70

70 - 75

75 - 80

Weight

Percentage

- 70 -


• Table showing standard deviation

Serial No.

Length (X)

X - X

( X – X ) 2

1 16.2 16.2 - 16.08 = 0.12 0.01

2 17.2 17.2 - 16.08 = 1.12 1.25

3 15.4 15.4 - 16.08 = -0.68 0.46

4 15.7 15.7 - 16.08 = -0.38 0.14

5 15.6 15.6 - 16.08 = -0.48 0.23

6 16.3 16.3 - 16.08 = 0.22 0.05

7 17.1 17.1 - 16.08 = 1.02 1.04

8 15.7 15.7 - 16.08 = -0.38 0.14

9 16.0 16.0 - 16.08 = -0.08 6.40

10 16.0 16.0 - 16.08 = -0.08 6.40

11 15.8 15.8 - 16.08 = -0.28 0.08

12 16.2 16.2 - 16.08 = 0.12 0.01

13 16.3 16.3 - 16.08 = 0.22 0.05

14 15.8 15.8 - 16.08 = -0.28 0.08

15 16.3 16.3 - 16.08 = 0.22 0.05

16 15.1 15.1 - 16.08 = -0.98 0.96

17 16.4 16.4 - 16.08 = 0.32 0.10

18 16.3 16.3 - 16.08 = 0.22 0.05

19 15.4 15.4 - 16.08 = -0.68 0.46

20 16.8 16.8 - 16.08 = 0.72 0.52

Standard deviation = √ 18.48

= 0.9

20 6

- 71 -


BAR GRAPH SHOWI NG STANDARD DEVI ATI ON OF SCADS

1

0

2

3

4

5

6

7

9 10 11 12 13 14 15 16 17 18 19 20

Number of scads

Standard deviation

1 2 3 4 5 6 7 8

- 72 -


CCOONNCCLLUUTTIIOONN::

In the presence study the mean length of the scads was

16.08cm. The standard deviation of the total length was 0.96.

From the above study it can be observed that all the fishes in

full population had a similar length. A smaller standard deviation

indicates that there was not much variation in the different length

measurements.

The most common group was 16.0 to 16.5 cm and the least is

16.5 to 17.0 cm. Since the size group was similar it can be

concluded that all the fishes could be from the same shoal.

Taking sample from a population is one way to study the

population. To ensure that there is least error and biasness. While

selecting samples, random sample is considered by studying the

h of a fish we can get an idea of the size of a fish in average lengt

fishing. Length measurement studies are useful to know the size and

maturity.

- 73 -


EENNVVIIRROONNMMEENNTTAALL IISSSSUUEESS

CCOONNCCEERRNNIINNGG EEYYDDHHAAFFUUSSHHII


Eydhafushi is the capital of Baa Atoll, which is situated in

5- degree and 72 degree east longitude. This is about 63 miles North

from Male’. The area of this island is around 0.5 kilometer. The

population of this island is about 3300 and most of the people earn

money by fishing. About 300 fishermen are present in this island.

TTHHEE MMAAJJOORR EENNVVIIRROONNMMEENNTTAALL IISSSSUUEESS IINN EEYYDDHHAAFFUUSSHHII::

1. Beach erosion

2. Coral mining

3. Dredging

4. Reclamation of land

5. Disposal of domestic waste

6. Sewage disposal

7. Depletion of ground water

- 74 -


11.. BBEEAACCHH EERROOSSIIOONN::

Strong waves and currents erode the soil from the beach into the

sea.

RReeaassoonnss ffoorr bbeeaacchh eerroossiioonn::

• Coral mining

When corals are mined, waves directly reach the beach. These

waves are strong enough to wash the sand away from the beach. As

the corals are taken off from the reef, it gets deeper providing the

current to flow with greater force so a coral area is not safe.

• Taking sands from beaches for constructing houses.

People take sand from the beaches for construction purpose. This

reduces the amount of sand in the beach and this helps the waves to

come to a long distance along the beach.

• Destruction of mangroves and coconut palms near the beach.

When the vegetation around the island is destroyed the sand gets

loose. The vegetation holds the soil with their roots. So waves

cannot wash away the soil easily. Therefore removal of vegetation

makes the soil loosely bond making the waves to erode the soil

easily.

SStteeppss ttaakkeenn bbyy tthhee ggoovveerrnnmmeenntt ttoo pprrootteecctt tthhee iissllaanndd ffrroomm bbeeaacchh

eerroossiioonn

The government banned:

i. Coral mining

ii. Cutting mangroves

iii. Removing sand from beaches.

- 75 -


22.. CCOORRAALL MMIINNIINNGG::

This is the removal of coral stones from the reefs for construction

purposes. This will increase the depth of seawater and changes the

habitats of baitfishes. People remove massive corals from the reef.

This is because of its massive structure, strength and hardness.

Not only coral mining do affect corals but anchoring on the reefs

also damages lot of habitat of coral reef species. Many branching

corals and table corals were destroyed. When the coral reefs are

destroyed, it will affect the island. It will cause soil erosion when the

waves directly reach the beach.

33.. DDRREEDDGGIINNGG::

This is the process by which lagoons of the islands are deepened.

This is for navigation and reclaiming lands. The heavy excavators

will remove the bottom soil along with the organisms found in the

bottom. This removal of bottom organisms reduces the amount of

demarsal fishes. The sedimentation produced during dredging last

for long and settles on the corals so that the corals gasp for oxygen.

It also reduces the light penetrating intensity reducing the

photosynthetic rate.

44.. RREECCLLAAMMAATTIIOONN OOFF LLAANNDD::

Increasing the size of the land by adding sands taken from the

lagoons in the past, the island was reclaim for construction purposes.

This interferes with natural cycle.

- 76 -


55.. DDIISSPPOOSSAALL OOFF DDOOMMEESSTTIICC WWAASSTTEE::

The waste product in the island is not treated well. It is burned

or buried in the garbage disposal area. When the waste are burned it

produces lot of smoke, which will cause air pollution and ocean

layer, rises. This result in global warming where the low lying

islands like Maldives is affected the most. So it is not good to burn

the waste. When we burry the waste it mixes with ground water,

polluting the water. So the waste affects the well water, we

commonly use. So it is advisable to recycle the waste in the island.

66.. SSEEWWAAGGEE DDIISSPPOOSSAALL::

The sewage is also not treated well. It is directly pump into the

sea without any treatment. When the sewage is pumped into the sea

it results eutrophication where excess phytoplankton grow blocking

the light intensity.

- 77 -


FFIISSHHIINNGG BBOOAATTSS IINN MMAALLDDIIVVEESS


Fishing vessels have been developed by Maldives based on

their experience and years of craftsmanship. In the past, they built

boats from the coconut timber, but now they use hard wood. Hard

wood is used where strength is needed in the boat. The traditional

hard wood used includes kandoo, funa, hirun’dhu, dhiggaa, kaani

and kuredhi. One very notable feature of these dhoanis is that they

are extremely stable. Steel is not at all used. Fasteners are made up

of copper.

The following are the various fishing vessels used in

Maldives.

1. Bokkura

2. Vadhudhoani

3. Masdhoani

- Sailing Masdhoani

- Mechanized Masdhoani

- Mark II Masdhoani

- 78 -


1. BBOOKKKKUURRAA

This is a traditional rowing boat with a planked hull. The boats

are between 2 – 3m long. Some of these boats have engines of 2 – 5

hp installed. However some islands they are propelled by using oars

or by a pole pushed against the bottom. Bokkuras are also used for

transporting the catch to the shore, from fishing within the Atoll.

Sometimes it is used for transporting people and their belonging

between anchored boats and the shore. The crew consists of two or

more men. They have a shallow hull, which is very stable.

- 79 -


DDIIAAGGRRAAMM SSHHOOWWIINNGG AA BBOOKKKKUURRAA

- 80 -


22.. VVAADDHHUUDDHHOOAANNII::

They are traditionally non-mechanized, sailing crafts of

about 6 – 8 meters. They are similar in construction to the sailing

masdhaonis. They are used within the Atoll or in the deep sea and in

the vicinity of the reef. The crew consists of 3 to 4 men. They have

sails and are propelled by wind power.

These dhaonis accounted for 60% of the total fleet in 1974

and 61% in 1984 and 52% by the year 1990. These boats are used

for short distance transport and other local purposes as well as for

fishing. Recently vessels have been mechanized with small diesel

engines.

- 81 -


DDIIAAGGRRAAMM SSHHOOWWIINNGG AA VVAADDHHUUDDHHOOAANNII

- 82 -


MMAASSDDHHOOAANNII::

Masdhoanis are used for pole and line fishing. There are

three types of masdhoanis

1. Sailing masdhoanis.

2. Mechanized masdhoanis.

3. Mark II masdhoanis.

11..SSAAIILLIINNGG MMAASSDDHHOOAANNIISS::

It is about 10 to 12 meters in length and 3 to 3.5 meters

across. They are used to operate in shallow lagoons. They do not

have superstructures. There are holes in the hull, which can be used

to flood the bait wells. There is a wooden platform on the aft of the

vessel where the skipper standards while steering and the crew

standards for pole and line fishing. There are about 6 – 12 people.

- 83 -


DDIIAAGGRRAAMM SSHHOOWWIINNGG AA SSAAIILLIINNGG MMAASSDDHHOOAANNII

- 84 -


22.. MMEECCHHAANNIIZZEEDD MMAASSDDHHOOAANNIISS::

Mechanized masdhoanis were introduced in

Maldives in the year 1972 with slight modification to the stern to

allow for the size of engines and additional vibration. These dhoanis

increased to 30% of the total fishing fleet by 1990. They are

generally longer than the traditional sailing dhoanis. They vary 10 –

15 meters in over all lengths and have a range of 40 – 45 miles and

are operated as day boats. To adopt a traditional sailing masdhoanis

for mechanization it is necessary to:

1) Strengthen the aft end of the hull with additional frames.

2) Change the shape of the stern stem.

3) Fix base block for the engine.

4) Make an aperture for the propeller shaft.

5) Add a watertight bulkhead in front of engine, decking over and

fitting with a hatch.

The masdhoanis is used pole and line fishing.

Mechanized ones is more efficient because it is not depended on the

variations of weather and can follow shoals of fishes. The stern

platforms on the mechanized dhoanis are use as a fishing platform.

The mid interior contains bait wells and is used to store live fishes.

Engines off 22hp and 30hp are used with great efficiency and for

easy maintenance.

- 85 -


DDIIAAGGRRAAMM SSHHOOWWIINNGG AA MMEECCHHAANNIIZZEEDD MMAASSDDHHOOAANNII

- 86 -


MMAARRKK IIII MMAASSDDHHOOAANNII::

These are well-designed modern dhaonis used in today’s

fishing. The speed and the vibration caused additional stress to the

structure of the boat. Although many masdhoanis have been

successfully mechanized. This stress is better provided for in the

designed of the mark II masdhoanis. It also has a 6 inches bulwark

to increase safety. Apart from using these dhoanis for fishing and

extra skill is needed in handling it. As the fish are broad on board,

they need an extra lift to get them over the 6 inches bulwark. To

mamoeuvre the boat especially in bringing the boat along side the

jetties and freezer boats, they must be well versed in using the

engine.

Distinguishing features of these dhoanis are that in the stern.

The dhoanis are completely decked over, making it easy to work on.

There are modifications to the engine, which allow it to be

controlled from above the deck.

- 87 -


DDIIAAGGRRAAMM SSHHOOWWIINNGG AA MMAARRKK IIII MMAASSDDHHOOAANNII

- 88 -


DDIIAAGGRRAAMM SSHHOOWWIINNGG PPAARRTTSS OOFF AA DDHHOOAANNII

- 89 -


KKNNOOTTSS


When two ends of the ropes are tied together a knot is formed.

Knot tying is very important for people like us and many others too.

It is very important because it is used to tie our boats to the jetty as

well as to an anchor. Various other activities done during our daily

life activities also require tying the knots. Different kinds of knots

are made for different purposes. Some of the commonly used knots

include;

1. Overhand knot

2. Figure eight knot

3. Square or reef knot

4. Sheet bend

5. Bow line

6. Fishermen’s knot

7. Two half hitches

8. Fishermen’s bend

9. Clove hitch

10. Snelling hook

11. Fishing hook knot

- 90 -


11.. OOVVEERRHHAANNDD KKNNOOTT::

Name : Overhand knot

Use : To prevent the ends of a rope from unlaying.

22.. FFIIGGUURREE –– EEIIGGHHTT KKNNOOTT::

Name : Figure-Eight knot

Use : To prevent the ends of a rope from unlaying.

- 91 -


33.. RREEEEFF KKNNOOTT::

Name : Reef Knot

Use : To tie two ropes of same diameter.

44.. SSHHEEEETT BBEENNDD::

Name : Sheet bend

Use : To tie two ropes of different diameter.

- 92 -


55.. BBOOWW LLIINNEE::

Name : Bow line

Use : To make a loop at the end of a rope.

66.. FFIISSHHEERRMMEENN’’SS KKNNOOTT

Name : Fishermen’s knot

Use : To tie two ropes of same diameter.

- 93 -


77.. TTWWOO HHAALLFF HHIITTCCHHEESS::

Name : Two half hitches

Use : To tie a rope to a pile or bollard.

88.. FFIISSHHEERRMMEENN’’SS BBEENNDD::

Name : Fishermen’s bend

Use : To tie a rope t a to a ring of an anchor or float.

- 94 -


99.. CCLLOOVVEE HHIITTCCHH::

Name : Clove hitch

Use : To tie rope to a pile or bollard

1100.. SSNNEELLLLIINNGG HHOOOOKK::

Name : Snelling hook

Use : To tie a ring eyed hook to a line

- 95 -


1111.. FFIISSHHIINNGG HHOOOOKK KKNNOOTT::

Name : Fishing hook knot

Use : Use to tie a flat shank hook to a line.

- 96 -

Fisheries Science Project 2005 Ibarahim Haleeem MV404

GGUUTT CCOONNTTEENNTT AANNAALLYYSSIISS

AAIIMM::

To study the different types of food eaten by a reef fish and a pelagic

fish.


Tuna (fresh)

Tray

Scissors

Scalpel

Forceps

Bone cutter

Microscope

Magnifying glass

Parrot fish (Reef fish)


Two fishes were selected for the studies. One was a pelagic fish

and the other was a reef fish. The belly of both the fishes was cut

open as follows.

A cut was made in the mid ventral line of the fish.

It was cut up to pelvic fin.

A 90-drgree turn was made and then cut up to the pectoral fin.

Then it was cut parallel to the lateral line and finally till the anus.

- 97 -


The flap was removed in to a dish contain water. The contents

was absorbed using a magnifying glass while the minute particles

was observed using microscope.


• Table showing the gut content of two fishes.

Pelagic fish (tuna) Reef fish (parrot fish)

Bait fish Detritus

Zooplanktons Digested matter

Pieces of shrimp Coralline matter

Crustacean Sand

- 98 -


CCOONNCCLLUUSSIIOONN:

In the study few bait fishes and zooplanktons in the gut of tuna

was observed. It is likely that the fish caught had just undergone

feedings.

In the case of reef fish the gut contents on observation showed

the presence of detritus and digested matter.

The gut contents were also studied under the microscope. During

the study lot of zooplanktons was observed in the gut of pelagic fish.

It is because they mainly feed on planktons.

- 99 -


LLIIVVEE FFIISSHH TTRRAANNSSPPOORRTTAATTIIOONN

AAIIMM::

To compare the survival of marine and fresh water fish while

transportation

MMAATTEERRIIAALLSS RREEQQUUIIRREEDD..

Aerator

Plastic bag (4 in number)

Plastic tube

Hand net.

PPRROOCCEEDDUURREE:

Aquarium fishes required for the study were collected from the

lagoon. The fishes were collected using a hand net while snorkeling

in the lagoon. The fishes were maintained alive in a plastic bucket.

The water in the bucket was changed at regular intervals to ensure

that oxygen availability for the fish.

Fresh water fish was collected from the fresh water well. Two

plastic bags were taken. It was labeled as A and B. Plastic bags A

and B were filled 1/3rd with clean seawater. Two other plastic bags

were taken. They were labeled C and D. Plastic bags C and D were

filled one-third with clean freshwater. The bags A and B were

stocked with marine fishes, while bags C and D were stocked with

fresh water fishes. The bags A and C were filled with oxygen using

an aerator, and when the bags filled the neck of the bags were tied.

- 100 -


So that no leak of oxygen will be there, while the other bags were

kept without oxygen tied.

All the bags were kept in a cool, dry place. At regular intervals

the survival of the fishes in these bags were observed. Reading of

survival period was noted.

- 101 -


OOBBSSEERRVVAATTIIOONN

Fish Volume

of water

Temperature Salinity Survival

period (hrs)

a) Seawater

1.With oxygen

2. Without

oxygen

Clownfish

Clownfish

300 ML

300 ML

29-degree C

29-degree C

33 PPT

33 PPT

30

15

b) Fresh water

1. With oxygen

2. Without

oxygen

Grouper

Grouper

300 ML

300 ML

29-degree C

29-degree C

38

14

- 102 -


CCOONNCCLLUUSSIIOONN

The present study showed that the fishes survived for longer time

with oxygen. The fresh water fish with oxygen survived for 38 hrs

and that without oxygen survived for 30 hrs. The marine fishes with

oxygen survival. A part from oxygen, better handling procedures are

recommended while transporting the fish for its longer survival.

- 103 -

Documents

Complete Fish Project