fishery traps (gargours) in saudi territorial waters of the arabian … · 2008. 9. 2. · adel...

Fishery Traps (Gargours) in Saudi Territorial Waters of the Arabian Gulf... 13

Fishery Traps (Gargours) in Saudi TerritorialWaters of the Arabian Gulf

Adel Ahmed Tharwat and Abdel Rahman Al-Gaber

Department of Aquatic Resources Development,Faculty of Agriculture and Food Sciences,

King Faisal University, P.O. Box 420, Hofuf 31982, Saudi [email protected]

Abstract. Despite of the economic importance of the traps (locallynamed Gargours), operating in the Saudi traditional fishery of theArabian Gulf, scatter studies dealt with this fishing gear. So, thepresent work describes and evaluates all subjects related to the catcha-bility of the fishery traps and their impacts on productivity of fishbiomass. The present work is achieved through the research projectnumber 5001 (1425-1426 H) financial supporting from deanship ofscientific research, King Faisal University. The catch analysis(systematic identification, quantity and quality), the catch per uniteffort (CPUE) and the seasonality of fishing (the relative abundanceduring the year) were studied, as well as, some biological aspects ofmajor fish species were investigated. Also, temperature and salinity ofthe surface Gulf water of the fishing area were measured. The resultsindicated that the water temperature was the major factor affectingthe fishing rates during the year, especially on the small traps. Thesmall traps have a passive effect on the stock biomass that contributedto more selection of immature fishes. The estimated annual percent-age of lost traps was higher for large boats than of small boats. Manyvaluable fish and crustacean species that belong to Lethrinidae,Serranidae, Lutjanidae, Siganidae, Carangidae, Haemulidae, Sparidae,Mullidae, Platycephalidae and Portunidae constituted the majority oftrap catch. Some recommendations were given for development offishery traps in Saudi territorial waters of the Arabian Gulf.

Keywords: Fishery traps, Catch per unit effort, Fishing gears, Biolog-ical parameters, Gargours, Arabian Gulf, Saudi Arabia.

13

JKAU: Mar. Sci., Vol. 17, pp: 13-31 (2006 A.D. / 1427 A.H.)

Adel Ahmed Tharwat and Abdel Rahman Al-Gaber14

IntroductionSaudi Arabia�s strongest advantage is it has 2,400 km coastline, 1800 km on theRed Sea and 600 km on the Arabian Gulf. The Arabian Gulf is connected withthe Gulf of Oman through the Strait of Hormuz. Local fish supplies in 2004were approximately 66591 metric tons, consisting of 55419 MT from themarine fisheries (83%) and 11172 MT from aquaculture (17%). The productionof the Red Sea, Arabian Gulf and International waters were 20448, 34961 and10 MT, respectively. Approximately, all landings (99.78%) of the Arabian Gulfcome from the traditional fisheries (FSSA, 2006). The traditional fishery refersto the fishing boats of 5-20 meters in length, that operate without the fishingtechnology equipments, while, the industrial fisheries use only shrimp trawl netand contributes only about 0.22% of the total landings from the Gulf. Four mainfishing gears were used in traditional fisheries, these are traps, shrimp trawl,then large and small meshsize gillnets, in addition, three other types (handline,longline and trolllines) were used.

Traps are the most dominant fishing gear used in the Arabian Gulf. Someauthors dealt with fisheries aspects in Saudi Arabia (Peacock and Alam, 1980;Kedidi et al., 1984; Olsen et al., 1996; PERSGA, 1997 and Tharwat, 2003, 2005a& b). The present study aims to describe and evaluate the status of fishery trapsincluding; the catch analysis (systematic identification, quantity and quality), thecatch per unit effort (CPUE), the seasonality of fishing (the relative abundanceduring the year), some biological aspects of harvested fish species. Also, tempera-ture and salinity of the surface Gulf water of the fishing area were measured.

Materials and MethodsMonthly fishing trips by large and small fishing boats using traps were

performed to collect data and fish specimens from Saudi territorial waters of theArabian Gulf during 2004-2005. The present work is achieved through theresearch project number 5001 (1425-1426 H) financial supporting from dean-ship of scientific research, King Faisal University. The catch of both large andsmall traps was recorded and identified to species according to Carpenter et al.(1997). A representative sample for the common species is taken for biologicalinvestigation. Surface water temperature and salinity of the fishing area weremeasured during the fishing trips. Each fish was measured for length (cm) andweight (g), and then it was dissected to identify sex, maturity stage, stomachcontent, then remove viscera to record gutted weight (g). Fresh gonads wereremoved and visually inspected for size, colour, vascularization and presence ofmilt and oocytes to determine the macroscopic (staged by eye) staging of freshovaries and testes followed Collins et al., 1998. Length at which 50% of fishesreach sexual maturity (length at first sexual maturity, Lm50) was estimated by


Fig. 1. The traditional catches (metric ton, MT) by type of fishing gears operating in Sauditerritorial waters of the Arabian Gulf during 1995-2004.

maturation curve method (Brule et al., 1999 and Burgos, 2001). The historicaldata of catch & effort represented by the number of traps were colleted from theFisheries Statistics of Saudi Arabia (FSSA, 1995~2004) to estimate the catchper unit effort (CPUE). CPUE is the catch of fish in weight (kg), obtained by adefined unit of fishing effort were estimated as described in Sparre and Venema(1992). The CPUE all over ten years (1995-2004) was investigated to assess therelative abundance of different fish stocks and fishing effort trend of the ArabianGulf. Means and standard deviation (m ± SD) were computed for all data duringthe different years by statistical software program (SAS, 1990).

Results and Discussion

Description of the Fishery

Figure 1 shows that traps are the most dominant type of traditional fishinggears throughout the years 1995-2004; their catch attains 14589 MT in 2004and represents 41.82% of the total traditional catch in the Arabian Gulf. Itdecreased by 387 MT or 2.58% in 2004 than the previous year. The traps (localname gargours), shrimp trawl, then large and small meshsize gillnets are themajor types of traditional fishing gears operate in the Arabian Gulf. These fish-ing gears harvested 89.4% of the total traditional catch, while the rest consisting10.6% of the total catch harvested by handline, longline and trolllines. How-ever, the total catch of the Arabian Gulf was 34961 MT in 2004, this total land-ing resemble a small increase in fishing quantity compared with last year. Thetraditional catch gradually increased during 1999-2004 to attain 34884 MTconsisting 99.78% of the total. This increase is due to the increase in landing of


Fig. 2. The traps fishing effort (%) of large fishing boats operate in Saudi territorial watersof the Arabian Gulf during 1995-2004.

Fig. 3. The traps fishing effort (%) of small fishing boats operate in Saudi territorial watersof the Arabian Gulf during 1995-2004.

some major species in the traditional sector, and the increase in number of fish-ing trips. While, the landing of industrial fishery declined to 77 MT represent-ing 0.22% of the total (FSSA, 2006) which, it obtained from shrimp trawlingonly. This sharply declined due to the overfishing throughout the previousyears. Figures 2 and 3 displayed the fishing effort (%) as the number of trapsused, fishing days and fishing trips during 1995-2004 for large and small fish-ing boats, respectively. The number of traps used in the large boats was morefluctuated with an increased pattern than in the small boats.


Table 1. Average monthly catch per unit effort as (kg/trap, kg/fishing day) and catch season-ality (kg/month) for both large and small traps operate in Saudi territorial watersof the Arabian Gulf during 2005.

Season MonthLarge traps Small traps

kg/trap kg/day kg/month kg/trap kg/day kg/month

Dec. 9.0 450 6750 2.9 145 2175

winterJan. 6.7 335 5025 1.8 90 1350

Feb. 7.5 375 5625 2.3 115 1725

mean 7.7 386.7 5800 2.3 116.7 1750

Mar. 17.9 895 13425 5.8 290 4350

springApr. 24.2 1210 18150 4.2 210 3150

May 22.0 1100 16500 2.7 135 2025

mean 21.4 1068.3 16025 4.2 211.7 3175

Jun. 14.5 725 10875 4.0 200 3000

summerJul. 16.7 835 12525 2.9 145 2175

Aug. 18.2 910 13650 2.7 135 2025

mean 16.5 823.3 12350 3.2 160.0 2400

Sep. 21.4 1070 16050 6.9 345 5175

autumn Oct. 18.2 910 13650 5.0 250 3750

Nov. 13.7 685 10275 3.8 190 2850

mean 17.8 888.3 13325 5.2 261.7 3925

Overall mean 15.8 792 11875 3.8 187 2850

Annual total � � 142500 � � 34200

Catch Per Unit Effort (CPUE) and Seasonality

Table 1 shows the average monthly catch per unit effort as (kg/trap and kg/fishing day) and catch seasonality (kg/month) for both large and small trapsoperating in Saudi territorial waters of the Arabian Gulf. It is obvious thatCPUE sharply decreased for both large and small traps during Winter season(7.7 and 2.3 kg/trap, respectively), this could be attributed to the decline in allphysiological activities of fishes during relatively cold temperature (11-15ºC).The maximum CPUE of large traps occurred during the spring season followedby autumn and then moderate value obtained during summer season (21.4, 17.8and 16.5 kg/trap, respectively). However, the maximum CPUE of small trapsoccurred during the autumn season followed by spring and then moderate valueobtained during summer season (5.2, 4.2 and 3.2 kg/trap, respectively). Thisvariation in the CPUE between large and small traps during seasons of the yearcould be attributed to the different size of the trap funnel opening and the differ-


ent ecological factors between deeper and shallow waters of the fishing areas.The monthly changes of catch per unit effort (kg/trap) according to the averagemonthly temperature (Cº) and salinity (�) of Saudi territorial waters of theArabian Gulf are shown in Fig. 4 and 5. On the other hand, the catch per uniteffort (kg/trap and kg/ fishing day) of both large and small fishing boats usedtraps in Saudi territorial waters of the Arabian Gulf during 1995-2004 were

Fig. 4. Monthly catch per unit effort (kg/trap) according to the average temperature ofSaudi territorial waters of the Arabian Gulf.

Fig. 5. Monthly catch per unit effort (kg/trap) according to the average salinity (�) ofSaudi territorial waters of the Arabian Gulf.


shown in Fig. 6 and 7, which are related to the effort as the fishing day and thenumber of traps, respectively. The data indicated that average catch/fishing dayrelatively fluctuated in the large boats during the years with a relative increaseat 2004, while it tended to increase in small boats to attain the same quantity at2003 followed by slight decline at 2004 (Fig. 6). On the other hand, the averageCPUE as catch/trap highly decreased in the large boats, but it relativelyincreased in small boats during the years to attain approximately equal value(Fig. 7) at 2003 then both declined at 2004. In addition, it can be noticed from

Fig. 6. The catch per unit effort (kg/fishing day) of large and small fishing boats operate inSaudi territorial waters of the Arabian Gulf during 1995-2004.

Fig. 7. The catch per unit effort (kg/trap) of large and small fishing boats operate in Sauditerritorial waters of the Arabian Gulf during 1995-2004.


the trips observations that the loss percentage of traps was higher in large boats(about 12%) than in small boats (about 8%), this may be due to the differentecological factors including water moving in deeper and shallow waters of thefishing areas.

Catch Composition

In the present work (Tables 2 and 3), it was found that all harvested fish &crustacean species by large and small traps belong to 10 major families, and thecatch composition was the same in both large boats (mainly using large traps indeep waters) and small boats (mainly using small traps in shallow waters). Theonly difference was in the fish size and quantity, where the mean fish sizesobtained by the large traps were bigger than mean fish sizes obtained by thesmall traps. This could be attributed to the variation in size of the trap funnelopening and fishing grounds. Fig. 8 shows the percentage of major fish andcrustacean groups caught by traps operating in the Saudi territorial waters of theArabian Gulf during 1995-2004. It is obvious that emperors, sea breams, group-ers, scads/jacks/ and trevallies, rabbit fishes, snapper and others (mainly crabs,Grunt, goatfish and bartail) were the common species in the catch throughout1995-2004. By following the CPUE of the groups, it was noticed that the rela-tive abundance of these groups fluctuated through years.

Table 2. Catch composition of major fish and crustacean families harvested by large trapsoperate in Saudi territorial waters of the Arabian Gulf during 2005.

No. Family Catch composition

kg %

1 Lethrinidae (Emperor) 37636 26.4

2 Serranidae (Grouper) 25946 18.2

3 Carangidae (Trevally) 24378 17.1

4 Lutjanidae (Snapper) 13686 9.6

5 Siganidae (Rabbitfish) 10692 7.5

6 Haemulidae (Grunt) 8981 6.3

7 Portunidae (Crab) 7556 5.3

8 Sparidae (Seabream) 6558 4.6

9 Mullidae (Goatfish) 4562 3.2

10 Platycephalidae (Bartail) 2566 1.8

Total 142560 100.0


Fig. 8. Catch composition of the traps fishing gear (Gargours) operating in Saudi territorialwaters of the Arabian Gulf during 1995-2004.

Biological Parameters

Fishes belong to each family were classified by species (Tables 4 and 5).Scientific and English names, average fish length (cm), average fish weight (g),length at first maturity sexual (Lm50) and their feeding habits. The present

Table 3. Catch composition of major fish and crustacean families harvested by small trapsoperate in Saudi territorial waters of the Arabian Gulf during 2005.

No. Family Catch composition

kg %

1 Lethrinidae (Emperor) 7353 21.5

2 Carangidae (Trevally) 6943 20.3

3 Siganidae (Rabbitfish) 5575 16.3

4 Serranidae (Grouper) 4138 12.1

5 Portunidae (Crab) 3488 10.2

6 Lutjanidae (Snapper) 2668 7.8

7 Haemulidae (Grunt) 1881 5.5

8 Sparidae (Seabream) 1402 4.1

9 Mullidae (Goatfish) 547 1.6

10 Platycephalidae (Bartail) 205 0.6

Total 34200 100.0


Tab

le 4

. Fis

h an

d cr

usta

cean

fam

ilies

of

larg

e tr

aps

iden

tifi

ed b

y sp

ecie

s ha

rves

ted

from

Sau

di t

erri

tori

al w

ater

s of

the

Ara

bian

Gul

f, a

ndso

me

biol

ogic

al a

spec

ts.

Spec

ies

M

ean

leng

thM

ean

wei

ght

Leng

th a

t

Fa

mily

(cm

± S

D)

(g ±

SD

)fir

st se

xual

Fee

ding

hab

it

En

glish

nam

e

S

cien

tific

nam

em

atur

ity (c

m)

Span

gled

empe

ror

Leth

rinus

neb

ulos

us44

± 5

.1 6

56 ±

12.

435

Mol

lusk

s, cr

usta

cean

s & ec

hino

derm

s

Leth

rini

dae

Snub

nose

empe

ror

Leth

rinus

bor

boni

cus

33 ±

3.0

342

± 1

1.0

29M

ollu

sks,

crus

tace

ans &

echi

node

rms

Pink

ear e

mpe

ror

Leth

rinus

lent

jan

39 ±

4.1

360

± 1

2.6

30M

ollu

sks,

crus

tace

ans &

echi

node

rms

Smal

ltoot

h em

pero

rLe

thrin

us m

icro

don

49 ±

5.3

567

± 1

4.2

33M

ollu

sks,

crus

tace

ans &

echi

node

rms

Redm

outh

gro

uper

Aeth

alop

erca

rogo

a50

± 3

.2 4

53 ±

9.

234

Smal

l fish

es &

mol

lusk

s

Serr

anid

aeO

rang

espo

tted

grou

per

Epin

ephe

lus c

oioi

des

56 ±

4.3

2268

± 1

7.0

48Fi

sh &

crus

tace

ans

Whi

tesp

otte

d gr

oupe

rEp

inep

helu

s cae

rule

punc

tatu

s52

± 3

.023

04 ±

16.

245

Fish

& cr

usta

cean

s

Are

olat

e gro

uper

Epin

ephe

lus a

reol

atus

38 ±

2.9

589

± 1

0.5

31Fi

sh &

crus

tace

ans

Indi

an th

read

fish

Alec

tis in

dicu

s48

± 5

.1 8

58 ±

16.

130

Smal

l fish

es, s

quid

s & cr

usta

cean

s

Long

nose

trev

ally

Cara

ngoi

des c

hrys

ophr

ys54

± 5

.710

20 ±

18.

035

Smal

l fish

es, s

quid

s & cr

usta

cean

s

Gol

den

treva

llyG

nath

odon

spec

iosu

s61

± 4

.8 5

65 ±

9.

128

Crus

tace

ans,

mol

lusk

s & sm

all f

ishes

Car

angi

dae

Tala

ng q

ueen

fish

Scom

bero

ides

com

mer

soni

anus

54 ±

5.5

445

± 1

0.3

34Sm

all s

quid

s & sm

all f

ishes

Ora

nges

potte

d tre

vally

Cara

ngoi

des b

ajad

47 ±

4.3

286

±

8.1

32Sm

all s

quid

s & sm

all f

ishes

Bige

ye tr

eval

lyCa

ranx

sexf

asci

atus

50 ±

4.0

450

±

8.9

30Sm

all f

ish &

crus

tace

ans

Gia

nt tr

eval

lyCa

ranx

igno

bilis

67 ±

6.7

1079

± 1

2.6

37Sm

all f

ish &

crus

tace

ans

Fishery Traps (Gargours) in Saudi Territorial Waters of the Arabian Gulf... 23T

able

4. C

ontd

.

Spec

ies

M

ean

leng

thM

ean

wei

ght

Leng

th a

t

Fa

mily

(cm

± S

D)

(g ±

SD

)fir

st se

xual

Fee

ding

hab

it

En

glish

nam

e

S

cien

tific

nam

em

atur

ity (c

m)

Bla

cksp

ot sn

appe

rLu

tjanu

s ful

vifla

mm

a30

± 2

.522

5 ±

6.7

20Sm

all f

ish &

crus

tace

ans

Lutja

nida

e E

hren

berg

�s sn

appe

rLu

tjanu

s ehr

enbe

rgii

25 ±

2.1

152

± 5.

319

Smal

l fish

& cr

usta

cean

s

Mal

abar

blo

od sn

appe

rLu

tjanu

s mal

abar

icus

57 ±

2.4

2190

± 1

5.9

39Sm

all f

ish &

crus

tace

ans

Hum

phea

d sn

appe

rLu

tjanu

s san

guin

eus

53 ±

2.3

2230

± 1

5.3

36Sm

all f

ish &

crus

tace

ans

Siga

nida

e W

hite

spot

ted

spin

efoo

tSi

ganu

s can

alic

ulat

us28

± 2

.0 2

20 ±

4.

619

Alg

ae &

Sea

gra

sses

Stre

aked

spin

efoo

tSi

ganu

s jav

us24

± 2

.1 1

43 ±

3.

218

Alg

ae &

Sea

gra

sses

Sor

did

swee

tlip

Plec

torh

inch

us so

rdid

us44

± 3

.6 2

36 ±

6.

232

Smal

l cru

stace

ans &

biv

alve

s

Hae

mul

idae

Silv

er g

runt

Pom

adas

ys a

rgyr

eus

38 ±

2.6

210

±

5.4

27Be

nthi

c inv

erte

brat

es &

fish

Bla

cksp

otte

d ru

bber

lipPl

ecto

rhin

chus

gat

erin

us39

± 3

.2 2

90 ±

5.

927

Smal

l fish

& cr

usta

cean

s

Port

unid

ae B

lue s

wim

min

g cr

abPo

rtunu

s pel

agic

usCL

11

± 1.

9 1

60 ±

2.

3�

Smal

l fish

& in

verte

brat

es

Yel

low

fin se

abre

amAc

anth

opag

rus l

atus

32 ±

2.5

196

±

4.1

24Ec

hino

derm

s, w

orm

s, cr

usta

cean

s & m

ollu

sks

One

spot

seab

ream

Dip

lodu

s sar

gus k

otsc

hyi

22 ±

1.2

129

±

2.6

18A

lgae

& sm

all i

nver

tebr

ates

Spar

idae

S

ilver

y se

abre

amSp

arid

ente

x has

ta30

± 2

.3 1

90 ±

4.

024

Smal

l fish

& in

verte

brat

es

H

affa

ra se

abre

amRh

abdo

sarg

us h

affa

ra31

± 2

.0 1

32 ±

3.

321

Bent

hic i

nver

tebr

ates

Tw

obar

seab

ream

Acan

thop

agru

s bifa

scia

tus

35 ±

2.1

289

±

4.7

25Sm

all f

ishes

& in

verte

brat

es

Mul

lidae

Yel

low

strip

e goa

tfish

Mul

loid

icht

hys f

lavo

lene

atus

24 ±

1.7

92

±

2.0

16Be

nthi

c inv

erte

brat

es

Cin

naba

r goa

tfish

Paru

pene

us h

epta

cant

hus

25 ±

1.6

107

±

2.2

17Be

nthi

c inv

erte

brat

es

Plat

ycep

halid

ae B

arta

il fla

thea

dPl

atyc

epha

lus i

ndic

us55

± 3

.5 4

05 ±

8.

640

Bent

hic i

nver

tebr

ates

& fi

shes


Tab

le 5

. Fis

h an

d cr

usta

cean

fam

ilies

of

smal

l tr

aps

iden

tifi

ed b

y sp

ecie

s ha

rves

ted

from

Sau

di t

erri

tori

al w

ater

s of

the

Ara

bian

Gul

f, a

ndso

me

biol

ogic

al a

spec

ts.

Spec

ies

M

ean

leng

thM

ean

wei

ght

Leng

th a

t

Fa

mily

(cm

± S

D)

(g ±

SD

)fir

st se

xual

Fee

ding

hab

it

En

glish

nam

e

S

cien

tific

nam

em

atur

ity (c

m)

Span

gled

empe

ror

Leth

rinus

neb

ulos

us32

± 4

.3 3

82 ±

12.

135

Mol

lusk

s, cr

usta

cean

s & ec

hino

derm

s

Leth

rini

dae

Snub

nose

empe

ror

Leth

rinus

bor

boni

cus

24 ±

3.2

199

± 1

0.0

29M

ollu

sks,

crus

tace

ans &

echi

node

rms

Pink

ear e

mpe

ror

Leth

rinus

lent

jan

27 ±

3.5

210

± 1

0.5

30M

ollu

sks,

crus

tace

ans &

echi

node

rms

Smal

ltoot

h em

pero

rLe

thrin

us m

icro

don

33 ±

5.1

331

± 1

2.3

33M

ollu

sks,

crus

tace

ans &

echi

node

rms

Redm

outh

gro

uper

Aeth

alop

erca

rogo

a34

± 3

.2 2

64 ±

9.

234

Smal

l fish

es &

mol

lusk

s

Serr

anid

aeO

rang

espo

tted

grou

per

Epin

ephe

lus c

oioi

des

35 ±

4.0

645

± 1

3.6

48Fi

sh &

crus

tace

ans

Whi

tesp

otte

d gr

oupe

rEp

inep

helu

s cae

rule

punc

tatu

s32

± 3

.5 7

60 ±

15.

245

Fish

& cr

usta

cean

s

Are

olat

e gro

uper

Epin

ephe

lus a

reol

atus

26 ±

2.7

294

±

8.6

31Fi

sh &

crus

tace

ans

Indi

an th

read

fish

Alec

tis in

dicu

s32

± 4

.9 4

29 ±

12.

030

Smal

l fish

es, s

quid

s & cr

usta

cean

s

Long

nose

trev

ally

Cara

ngoi

des c

hrys

ophr

ys36

± 4

.7 5

10 ±

14.

335

Smal

l fish

es, s

quid

s & cr

usta

cean

s

Gol

den

treva

llyG

nath

odon

spec

iosu

s41

± 4

.2 2

82 ±

7.

428

Crus

tace

ans,

mol

lusk

s & sm

all f

ishes

Car

angi

dae

Tala

ng q

ueen

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investigation revealed that harvested fishes by traps belong to different fishcategories concerning size & shape, feeding behavior and natural habitats.Concerning feeding behavior, the catch contains fishes belonging to herbivor-ous fishes such as Siganidae, fishes belonging to carnivorous fishes such asSerranidae and fishes belonging to omnivorous fishes such as Sparidae. Accord-ing to their natural habitats, there are demersal fishes such as Platycephalidae &Mullidae and intermediate water column fishes such as Lethrinidae and Caran-gidae. It is obvious that the mean size of fishes harvested by small traps wassmaller than fishes harvested by large traps and less than their Lm50.

Impacts of Traps

Traps are static bottom fishing gears anchored to the seabed and left to fishpassively, the traps mostly baited by breads and occasionally by trash fishes,squids or chicken intestine to attract target species through one or more entranc-es into traps. Since the areas of seabed affected by each trap is likely to be insig-nificant compared with the widespread effects of mobile fishing gears. How-ever, the fishing effort may be significant if concentrated in relatively smallareas with communities of long-lived fauna. Some studies made in northernEurope (Millner, 1985; Potter and Pawson, 1991 and Eno et al., 1996) indicatedthat the direct contact of static fishing gears with fauna may not be the primarycause of mortality and the frequency and intensity of physical contact is morelikely to be important. Fish traps usually deployed around coral reef areaswhere a proliferation of coral growth makes handline fishing difficult. In theArabian Gulf fisheries, the average life of a trap is estimated by the fishermento be from two to three years, depending upon where the trap is habituallyplaced. In proportion to the actual number of traps lost, the fishermen stoutlymaintain that their most serious natural enemy is other fishermen; this threat ofstealing has had an inhibiting effect on the entire industry and is the reasonbehind several practices. These usually include the scraping, scouring and resus-pension of substratum and occur against a background of natural disturbance.The direct effects of a given fishing method on infaunal and epifaunal commu-nities will tend to increase with depth and the stability of the substrate. In shel-tered areas where complex habitats develop at minimal depth, such as coralreefs, the direct effects of fishing may be marked and have profound effects onthe ability of the habitat to sustain fish production. The abundance of many reeffishes is positively correlated with topographic complexity (Risk, 1972; Porteret al., 1977; Luckhurst and Luckhurst, 1978; Carpenter et al., 1981; Thresher,1983; Kaufman and Ebersole, 1984; Patton et al., 1985; Roberts and Ormond,1987; Grigg, 1994 and Jennings et al., 1995) and habitat complexity will alsoinfluence the rates at which larval fish recruit to the reef from the plankton(Jones, 1992 and Connell and Jones, 1991). The differences are greater when


large well-developed areas of reef compared with areas that have been fisheddestructively until little topographic complexity remains (Pauly et al., 1989).Once it has been lowered traps to the bottom, no buoy used to mark the locationof the trap, the owner who usually records the spot by his GPS apparatus formemorizing the position of each trap. When several hundred traps are owned bya fisherman, this system obviously becomes impractical: in such case, only thelocations of key traps are remembered to help recover the additional traps thatare placed about them in the same general area. Once a boat stationed over oneof these key traps, finding the outlying traps usually presents no difficulty.How-ever, if the key trap has been destroyed or removed, it sometimes becomesvirtually impossible to locate them and the entire sequence may become tempo-rarily lost. The elaborate routine connected with hauling a series of traps to thesurface is known as "running", before the fisherman can run a trap, his helpermust station the boat directly over the spot by "planting a setting" pole or usingrobe connected with winch. The trap raises to the surface by inserting the tinesof the hooking pole under the frame above the entrance and lifting with a rapidhandover-hand motion. After the fishes have been removed, the fishermanhastens to inspect the trap to make certain that it is his own before proceedingany further with the cleaning operations. Cleaning of the trap have been accom-plished by passing an ordinary stiff bristle scrub brush over the slats and frameto reduce any flourishing marine growth. If left uncleaned, the traps not onlydeteriorate more rapidly but also do not seem to attract as many fishes.

Compared with the proportions of target species removed by mobile fishinggears, the number of organisms removed by traps is probably small. However,these fisheries tend to be highly localized leading to a concentration of lost gearwithin relatively small areas. Consequently, the proportion of local stocksremoved can be significant (Kruse and Kimber, 1993). Furthermore, many ofthese species have a high individual value and hence represent a large economicloss to the local fishing industry. In order to reduce these losses for undersizedspecimens, escape panels now fitted to many traps used in North America andbiodegradable materials are used to ameliorate losses (Guillory, 1993 and Polo-vina, 1994).

Some recommendations for the improvement of the fishery�s traps could besuggested. First, the fishing effect must be controlled for the marine fisheries asa whole, it should be reminded that overfishing is brought about not only byincreased fishing effort but also by the employment of destructive gears andtechniques by fishermen. Hence, the effective enforcement of the fishery laws,rules and regulations related to destructive gears must be pursued. In addition,small traps with small opening funnel and small mesh size have a passive effecton the reproductive cycle of many fish species, that they catch large number of


immature fishes. Therefore, it could be recommended to operate the large andmedium traps only while the small traps should be forbidden.

References

Brule, T., Deniel, C., Colas-Marrufo, T. and Sanchez-Crespo, M. (1999) Red grouper repro-duction in the southern Gulf of Mexico, Trans. Am. Fish. Soc., 128 (3): 385-402.

Burgos, J.M. (2001) Life History of the Red Grouper (Epinephelus morio) of the North Carolinaand South Carolina Coast, Master�s Thesis, University of Charleston, South Carolina.

Carpenter, K.E., Miclat, R.I., Albaladego, V.D. and Corpuz, V.T. (1981) The influence ofsubstrate structure on the local abundance and diversity of Philippine reef fishes, Proceed-ings of the Fourth International Coral Reef Symposium, 2: 497-502.

Carpenter, K.E., Krupp, F., Jones, D.A. and Zajonz, U. (1997) FAO Species IdentificationGuide for Fishery Purposes, Living Marine Resources of Kuwait, Eastern Saudi Arabia,Bahrain, Qatar, and the United Arab Emirates. Food and Agriculture Organization of theUnited Nations, Rome, Italy.

Collins, L.A., Johnson, A.G., Koenig, C.C. and Baker, Jr. M.S. (1998) Reproductive patterns,sex ratio, and fecundity in gag, Mycteroperca microlepis (Serranidae), a protogynousgrouper from the northeastern Gulf of Mexico, Fish. Bull., 96: 415-427.

Connell, S.D. and Jones, D.P. (1991) The influence of habitat composition on post recruitmentprocesses in a temperate reef fish population, Journal of Experimental Marine Biology andEcology, 151: 271-294.

Eno, N.C., MacDonald, D. and Amos, S.C. (1996) A Study on the Effects of Fish (Crustacea/mollusc) Traps on Benthic Habitats and Species, Report to European Commission Directo-rate General XIV, Studies Contract 94/076, 43 p.

FSSA (1995~2004) Fisheries Statistics of Saudi Arabia, Marine Fisheries Department, Ministryof Agriculture, Kingdom of Saudi Arabia.

FSSA (2006) Fisheries Statistics of Saudi Arabia, 2004, Marine Fisheries Department, Ministryof Agriculture, Kingdom of Saudi Arabia.

Grigg, R.W. (1994) Effects of sewage discharge, fishing pressure and habitat complexity oncoral ecosystems and reef fishes in Hawaii, Marine Ecology Progress Series, 103: 25-34.

Guillory, V. (1993) Ghost fishing by blue crab traps, North American Journal of FisheriesManagement, 13: 459-466.

Jennings, S., Grandcourt, E.M. and Polunin, N.V.C. (1995) The effects of fishing on the diver-sity, biomass and trophic structure of Seychelles' reef fish communities, Coral Reefs, 14:225-235.

Jones, J.B. (1992) Environmental impact of trawling on the seabed: a review, New Zealand Jour-nal of Marine and Freshwater Research, 26: 59-67.

Kaufman, L.S. and Ebersole, J.P. (1984) Microtopography and the organisation of two assem-blages of coral reef fishes in the West Indies, Journal of Experimental Marine Biology andEcology, 78: 253-268.

Kedidi, S.M., Abushusha, T. and Allam, K. (1984) Description of the Artisanal Fishery atTuwwal, Saudi Arabia: Catches, Efforts and Catches per Unit Effort, Survey conductedduring 1981-82. Cairo, Project for Development of Fisheries in Areas of the Red Sea andGulf of Aden. UNDP/FAO RAB/81/002/1:17.


Kruse, G.H. and Kimber, A. (1993) Degradable Escape Machanisms for Pot Gear: A SummaryReport to the Alaska Baord of Fisheries, Alaska Department of Fisheries and Game,Juneau.

Luckhurst, B.E. and Luckhurst, K. (1978) Analysis of the influence of substrate variables oncoral reef fish communities, Marine Biology, 49: 317-323.

Millner, R.S. (1985) The Use of Anchored Gill and Tangle Nets in the Sea Fisheries of Englandand Wales MAFF, Directorate of Fisheries Research, Lowestoft.

Olsen, D.A., Abdulrazzak, M.J., Elgowhary, S., Khan, A. and Al-Kouli, S. (1996) Manage-ment of Growth in the Coastal Zone: Jeddah, Kingdom of Saudi Arabia, MEPA Tech.Report.

Patton, M.L., Grove, R.S. and Harman, R.F. (1985) What do natural reefs tell us about design-ing artificial reefs in southern California, Bulletin of Marine Science, 37: 279-298.

Pauly, D., Silvestre, G. and Smith, I.R. (1989) On development, fisheries and dynamite: A briefreview of tropical fisheries management, Natural Resource Modeling, 3: 307-329.

Peacock, N.A. and Alam, K. (1980) Final Report. The fishery resource survey of the SaudiArabia Red Sea. February 1977-October 1979, Field Report, Fisheries DevelopmentProject, Kingdom of Saudi Arabia, (40): 28 p.

PERSGA (1997) Strategic Action Programme for the Red Sea and Gulf of Aden, National Fisher-ies Report: Kingdom of Saudi Arabia.

Polovina, J.J. (1994) The Lobster Fishery in the North-western Hawaiian Islands, In: "SpinyLobster Management" (B.F. Phillips, J.S. Cobb and J. Kittaka, Eds), pp: 83-90, BlackwellScientific Publications, London.

Porter, J.W., Porter, K.G. and Batac-Catalan, Z. (1977) Quantitative sampling of Indo-Pacificdemersal reef plankton, Proceedings of the Third International Coral Reef Symposium, 1:105-112.

Potter, E.C.E. and Pawson, M.G. (1991) Gill netting, Laboratory Leaflets, MAFF, Directorateof Fisheries Research, Lowestoft, 69: 34 p.

Ricker, W.E. (1975) Computation and interpretation of biological statistics of fish populations,Bull. Fish. Res. Board Can., 191: 383.

Risk, M.J. (1972) Fish diversity on a coral reef in the Virgin Islands, Atoll Research Bulletin,153: 1-6.

Roberts, C.M. and Ormond, R.F.G. (1987) Habitat complexity and coral reef fish diversity andabundance on Red Sea fringing reefs, Marine Ecology Progress Series, 41: 1-8.

SAS (1990) Statistical Analytical Systems Userís Guide, (Vol. 2), Cary, NC: SAS Institute Inc.USA.

Sparre, P. and Venema, S.C. (1992) Introduction to tropical fish stock assessment, Part I: Manu-al, FAO Fisheries Technical Paper No. 306, Revision I: 376 p.

Tharwat, A.A. (2003) Evaluation of the traditional fishing gear (Haddrah) along the coastline ofArabian Gulf in Saudi Arabia, J. Agric. Sci. Mansoura Univ., 28 (8): 6011- 6028.

Tharwat, A.A. (2005a) Fishery assessment of the rabbitfish Siganus canaIiculatus from theArabian Gulf, Saudi Arabia, Egypt. J. Aquat. Biol. & Fish., 9 (1): 117-136.

Tharwat, A.A. (2005b) Stock assessment of Orange-Spotted Grouper Epinephelus coioidesinhabiting the Arabian Gulf at Saudi Arabia, Saudi Journal of Biological Sciences, SaudiBiological Society, Saudi Arabia, 12 (2): 81-89.

Thresher, R.E. (1983) Environmental correlates of the distribution of planktivorous fishes in theOne Tree Reef Lagoon, Marine Ecology Progress Series, 10: 137-145.


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