TREND ANALYSIS OF SOME COMMERCIAL FISHES CATCH IN THE RIVER NILE IN UPPER EGYPT

TREND ANALYSIS OF SOME COMMERCIAL FISHES CATCH IN THE RIVER

NILE IN UPPER EGYPT.

I. A. Mekkawy, U. M. Mahmoud, and E. M. Hassanein

Departement of Zoology, Faculty of Science, Assiut University,

Assiut, Egypt.

ABSTRACT

The data of catch of some important fishes in the River Nile and

fishing effort expressed as a number of fishing boats were obtained

from the statistical reports of the General Authority for

Development of Fish Resources (GADFR, 1995-2010) and publications of

Central System of General Filling and Statistics (1980- 1994) were

considered for trends through such a period. The total annual catch

of the different species of fish from the Nile during the period

1980 to 2010 indicated that tilapiines contributed the higher

percentage of the total catch (47.74%) while Clarias gariepinus

constituted 16.02%, Bagrus sp. 8.74%, Lates niloticus 3.26 and S. schall

2.41% of the total catch of the River Nile. At annual scale,

different types of the total production catch, teleosts and species

group catch by all gears fluctuated with different variability. The

catch trends of fish species groups catch through the total period

1980-2010 showed an increase in catch until it reached the highest

value at 2002 then a gradual decrease occurred. During recent years,

the ecosystem of the Nile has been subjected to some ecological

changes especially after the construction of the High Dam. Several

fish species declined from the commercial fishery of the Nile, while

other species flourished in the new ecological conditions. Moreover,

there is an obvious increase in fishing intensity duo to the

increased number of fishing boats.

Keywords: Trend analysis; stock assessment; Tilapiines; River

Nile.

INTRODUCTION

River Nile is considered the principle artery for Egyptian life.

Since the early times, the River Nile is the main water source in

Egypt, origin of the fertile land, and it has sustained since its

existence man's early civilization. Fish are considered among the

most important source of animal protein in Egypt. The demand for

increasing fish production in Egypt has become a great necessity due

to the rapid growth of its population. In Egypt, although there are

vast aquatic resources, the optimum utilization and the proper

management of natural fisheries are urgently needed to increase fish

production. Many fish species are still dominant in the Nile, while

several fish species are declining and probably disappearing from

the commercial fisheries catch (Tharwat, 1995).

Stock assessment is the part of fisheries science that studies

the status of a fish stock as well as the possible outcomes of

different management alternatives. It tells us if the abundance of a

stock is below or above a given target point and by doing so lets us

know whether the stock is overexploited or not, it also tells us if

a catch level will maintain or change the abundance of the stock

(Bonfil, 2005).

A list for all the Nile fishes found in the commercial catch was

reported by Fawzi (1928& 1930) who identified 30 species sold in the

fish markets as a commercial fishes . He also identified 28 species

of Henrichromis, Haplochrromis and Cyprinidae as small beautiful colored

fishes in the Nile and Delta lakes. While Karam (1940) identified 47

fish species inhabiting the Egyptian Nile waters.

El-Sedfy and Kheir (1990) recorded 31 species including the

commercial and non-commercial fishes. They found that only 17

species can be considered as a commercial fishes.

The importance of the River Nile as the main source of fish

production in Egypt encouraged many investigators to study the Nile

fishes for along time (For example, Jensen (1958), Bishara (1967),

Mekkawy (1987, 1990, 1995a, 1997a, b), Mahmoud (1988), Mekkawy and

Mahmoud (1992), Khalil(1994), Okail (1999), Ali (2003), Ahmed

(2007)).

In Egypt the fishery resources are concenterated on the Delta,

inland lakes and the Nile. The latter supplies the lakes by more

than 75% of their production from fishes. The control of the Nile by

construction of Aswan High dam results in significant changes in its

physicochemical and biological characteristics. Similarly. Changes

in the river velocity invariably affected its water quality and

ecosystem characteristics, Toullabah (1996). Furthermore, the Nile

receives increasing amounts of waste discharges from several sources

as the river travels northward.

The present study was performed to assess fish stocks of

fisheries of some fish species of River Nile and this study has been

suggested due to the importance of the River Nile for fish

production to Egypt, so catch statistics and CPUE (Catch per unit

effort) are measures of relative stock abundance that can be used

(with some limitation) to compare the abundance of a fish stock over

a period of time.

Fig. 1: Map showing the area of study from Cairo to Aswan

along the River Nile.

MATERIALS AND METHODS

1- Collection of Fishery data

Data concerning the total production catch, total teleosts

fishes catch, commercial fish species catch (Tilapiines, Bagrus

fishes, Clarias gariepinus and Synodontis schall ) and fishing effort

expressed as a number of fishing boats in the River Nile were

obtained from the statistical reports of the General Authority for

Development of Fish Resources (GADFR, 1995-2010) and publications of

Central System of General Filling and Statistics (1980- 1994).

2- Analysis of catch data

The data of catch of some important fishes (Tilapiines, Bagrus

fishes, Clarias gariepinus, and Synodontis schall) from the year 1980 to 2010

were considered for trends through such a period.

Statitical analysis were performed to calculate the average,

coefficient of variation, standared deviation and range of fish

species catch along this period.

Multiple linear regression analysis was performed to calculate

the regression equation and correlation coefficient.

RESULTS

At annual scale,different types of the total production catch,

teleosts and species group catch by all gears fluctuated with

different variability (Tables 1-5). Except for total production and

tilapiines catch (P = 0.47 and 0.48 respectively), the distributions

of other catches deviated from normality (p <0.001).

Fish species group catch have no significant correlation with

effort in terms of boats. Tilapiines catch over 1980-2010 period had

a positive correlation with Clarias gariepinus, Bagrus and Labeo with

correlation coefficient β = 0.79, 0.57 , 0.24 and R2= 0.87, 0.91,

0.58 respectively and a negative correlation with Synodontis schall (β =

-0.756 & R2 = 0.91 ).

The contributions of the most economic groups to the total

production catch can be modeled in terms of the following multiple

linear regression equation:

Total production catch = -15631.1 + 1.7 Tilapiines + 1.5 C. gariepinus

+ 4.4 S. schall + 10.5 Labeo.

All the parameters of this equation were significant (P<0.009)

with adjusted R2 of 0.98. The boats had no significant effect and so

was excluded.

Tilapiines catch had a negative correlation with Synodontis schall

catch while the contribution of the other fish groups to the

tilapiines catch can be modeled in terms of the following multiple

linear regression equation:

Tilapiines catch = 13476.83 + 0.78 Bagrus + 0.75 Clarias gariepinus +

1.93 Labeo – 3.53 Synodontis schall .

The parameters are highly significant (P< 0.028) with adjusted

R2 of 0.86. Boats and Other species group catch contributed

insignificantly and in turn were excluded from this model.

Through 1980- 2010 periods, the trends in the total production,

teleosts and other fish species catch (Figs. 2&3) generally

summarized by the following equations:

Total production catch= 3201.9 Years+ 8841.8

R2=0.8152

Teleosts catch = 2972.9 years + 6387

R2 = 0.7979

Tilapiines catch= 611.48 years+ 14138

R2= 0.7426

Bagrus catch= 347.33years +171.26

R2= 0.4504

Clarias gariepinus catch= 614.65 years + 639.45

R2= 0.6778

Synodontis schall catch= 97.27 years + 52.484

R2 =0.4084

The catch trends showed slight or no increase through the total

period 1980-2010 (Figs. 2&3) due to the high variability and

fluctuation at the annual time scale especially the decline in the

latter period. The teleosts catch is mainly composed of average

values of 47.74% tilapiines, 16.02% Clarias gariepinus, 13.56% Eels,

8.74% Bagrus and 18.29% Atherina boyeri, 2.09% labeos, 12.72% Lates niloticus,

2.41% Synodontis schall and 39.97% grass carp (Table 2 ) with CV of

0.34, 0.37, 2.52, 0.39, 2.02, 0.32, 2.32, 0.37 and 1.09 respectively

.

Further inspection of the total production catch, teleosts and

tilapiines catch (Figs. 4&5) leads to classification of these

catches into two stages:

In the first period (1980-2002), the total production, Teleosts

and Tilapiines catches increased significantly with time and can be

described by the following trends:

Total production catch= 3840.2 years+ 2127.6

R2 = 0.791

Teleosts catch = 3206.9 years + 3416.8

R2= 0.7757

Tilapiines catch= 854.1 years+ 11742

R2= 0.9186

In the second period (2003-2010), the total production, teleosts

and tilapiines catch exhibited significant decreased trends with

coefficient of variations of 14.40, 14.17 and 13.63 respectively.

So, the decline of the River Nile production in the latter years is

evident. The trends of total production, teleosts and tilapiines

catch can be described by the following equations in the latter

periods:

Total production catch= -4147.9 Years+ 112838

R2 = 0.5616

Teleosts catch = -4044.4 years + 106809

R2 = 0.6221

Tilapiines catch= -858.02 Years+ 33332

R2= 0.2738

At Cairo Sector, total production, teleosts and tilapiines catch

during the period 1990-2010 (Figs. 6-8) can be explained by the

following equations:

Total production catch= 170.76 years + 1745.7

R2= 0.2358


R2 = 0.2564

Tilapiines catch = 39.536 years + 1098.9

R2 = 0.0465

The catch trends showed slight or no increase through the total

period 1990-2010 (Fig. 5) due to the high variability and

fluctuation at the annual time scale especially the decline in the

latter period, which reflect the general trends of the River Nile.


tilapiines catch (Figs. 7&8) leads to classification of these

catches into two stages:

In the first period (1990-2002), the total production, teleosts



Total production catch = 458.93 years – 203.9

R2 = 0.8126

Teleosts catch = 413.4 years -195.88

R2 = 0.8264

Tilapiines catch = 112.04 years + 519.31

R2 = 0.5167


and tilapiines catch exhibited significant decreased trends and can

be described by the following equations:

Total production catch= -858.19 years+ 8485.9

R2= 0.8809

Teleosts catch = -832.37 years + 8190.3

R2 = 0.8475

Tilapiines catch= -508.67 years+ 4196.8

R2= 0.5533

At Assiut station, total production, teleosts and tilapiines

catch during the period 1990- 2010 (Fig. 9) can be described by the

following equations:

Total production catch = 242.62 years + 825.79

R2 = 0.3535


R2 = 0.4325

Tilapiines catch = 42.36 years +53.012

R2 = 0.4681


tilapiines catch at Assiut station (Figs. 10&11) leads to

classification of these catches into two stages:

In the first period (1990-2002), the total production, teleosts



Total production catch= 565.2 years – 1217.7

R2 = 0.7656

Teleosts catch = 511.9 years – 1519.2

R2= 0.6841

Tilapiines catch= 79.416 years – 184.49

R2 = 0.7934


and tilapiines catch exhibited significant decreased trends which

can be described by the following equations:

Total production catch= -457.87 years + 6783.3

R2= 0.2686


R2 = 0.2091

Tilapiines catch= -47.155 years+ 971.07

R2= 0.1225

The third site along the River Nile is Aswan station (Fig. 12)

where the catch equations are:

Total production catch = -120.65 years + 4975

R2 = 0.2734


R2 = 0.2451

Tilapiines catch = -142.63 years + 4232.1

R2 = 0.5298

There are significant decreased trends with coefficient of

variations 41.26, 40.30 and 45.65 for total production, teleosts and

tilapiines catches respectively.

Table 1: Total production, commercial species catch (tons) and

effort from River Nile from the period 1980 to 2010, data from the

publications of Central System of General Filling and Statistics

(1980-1994) and GADFR (1995-2010).

Year

Tilapiines

Clar

ias

garie

pinu

s

Bagr

us sp.

Late

sni

lotic

us

Eels

Syno

dont

issc

hall

Athe

rina

boye

ri

Labe

o

grass carp

Others

Total

production

No. of

boats

19801498

7 966 2184 -

- 327

- 474

- 1062 20000

12277

19811495

4 896 2193 -

- 382

- 532

- 1043 20000

12662

19821449

8 877 2565 -

- 468

- 574

- 1018 20000

13544

19831566

4 601 2218 252 1 361 18 436 - 449 20000

14204

19841358

6 3452 1677 93 - 366 25 197

- 514 19910

15213

19851474

5 2377 1913 90 419 353 409 580 - 1730 22616

13186

19861837

5 2962 510 2384 112 440 - 723

- 2156 27662

15998

19871960

4 3160 544 2543 119 469 - 771

- 2300 29510

16414

19881662

9 3802 299 2000 503 821 406 717 - 5349 30526

14363

19892074

21024

1 2173 - 210 638 62 221

- 3535 38673

15740

19902261

1 9539 2809 141 165 458 279 330 64 5275 416711635

3

19912327

7 9076 2884 144 189 819 505 542 300 3513 412491661

4

19922181

3 9496 2378 123 2051019 449 569 205 3363 39620

14233

19932350

11014

8 4596 666 5091294 623

1243 218 7142 49940

35503

19942554

71132

2 5845 763 3312021 949

1531 628 8576 57513

18025

19952191

41075

5 5391 840 2741799 908

1632 349

14013 57875

13701

19962550

41131

0 5826 795 1931715 875

1441 534

16210 64403

19360

19972640

21231

7 5902 787 2731553 935

1386 3603

12377 65535

13728

19982656

61161

3 5723 1223 2011581 887

1230 3559

15451 68034

41606

19992719

41095

1 5665 1248 3271777

1058 783 1592

13326 63921

14608

20003088

51448

6 8395 1671 3772563

1731

1217

11142 7839 80306

16757

20013295

52321

51547

2 3745 2693923

3657

1716

14550 9936

109438

18360

20023384

72543

81902

4 4264 4755493

4843

1608

16469 8978

120439

37101

20032888

12515

81643

7 7481 5145985

4305

2237

18054 8588

117640

39458

20043629

01299

21022

8 8453 4661843

2036

2562

23712 5376

103958

32604

20052787

41342

2 7900 2917 3501454

1745

2111

22317 2950 83040

28507

20063418

71553

21195

2 5939210

52038

4205

3501

19435 4997

103891

15765

20073019

81529

5 6668 4536 9761843

6881

2359

21629 6223 96608

32119

20082425

61468

5 5647 3982 4111903

4431

1908

16911 4699 78833

23724

20092610

11534

5 7202 3658 4422297

4176

2161

19235 4950 85567

11811

2798 1326 187 543 159 1730 1204

Table 2: % of commercial species catch from River Nilefrom the period 1980 to 2010.

Year

Tilapiin

esp

ecies

Clar

ias

garie

pinu

s

Bagr

us sp.

Late

sni

lotic

usEels

Syno

dont

issc

hall

Athe

rina

boye

riLa

beo

grass

carp

198074.94

4.83

10.92 - -

1.64 -

2.37 -

198174.77

4.48

10.97 - -

1.91 -

2.66 -

198272.49

4.39

12.83 - -

2.34 -

2.87 -

198378.32

3.01

11.09

1.26

0.01

1.81

0.09

2.18 -

198468.24

17.34

8.42

0.47 -

1.84

0.13

0.99 -

198565.20

10.51

8.46

0.40

1.85

1.56

1.81

2.56 -

198666.43

10.71

1.84

8.62

0.40

1.59 -

2.61 -

198766.43

10.71

1.84

8.62

0.40

1.59 -

2.61 -

198854.47

12.45

0.98

6.55

1.65

2.69

1.33

2.35 -

198953.63

26.48

5.62

2.20

0.54

1.65

0.16

0.57 -

199054.26

22.89

6.74

0.34

0.40

1.10

0.67

0.79

0.15

199156.43

22.00

6.99

0.35

0.46

1.99

1.22

1.31

0.73

199255.06

23.97

6.00

0.31

0.52

2.57

1.13

1.44

0.52

199347.07

20.32

9.20

1.33

1.02

2.59

1.25

2.49

0.44

199444.42

19.69

10.16

1.33

0.58

3.51

1.65

2.66

1.09

199537.86

18.58

9.31

1.45

0.47

3.11

1.57

2.82

0.60

199639.60

17.56

9.05

1.23

0.30

2.66

1.36

2.24

0.83

199740.29

18.79

9.01

1.20

0.42

2.37

1.43

2.11

5.50

199839.05

17.07

8.41

1.80

0.30

2.32

1.30

1.81

5.23

199942.54

17.13

8.86

1.95

0.51

2.78

1.66

1.22

2.49

200038.46

18.04

10.45

2.08

0.47

3.19

2.16

1.52

13.87

200130.11

21.21

14.14

3.42

0.25

3.58

3.34

1.57

13.30

200228.10

21.12

15.80

3.54

0.39

4.56

4.02

1.34

13.67

200324.55

21.39

13.97

6.36

0.44

5.09

3.66

1.90

15.35

200434.91

12.50

9.84

8.13

0.45

1.77

1.96

2.46

22.81

200533.57

16.16

9.51

3.51

0.42

1.75

2.10

2.54

26.88

200632.91

14.95

11.50

5.72

2.03

1.96

4.05

3.37

18.71

200731.26

15.83

6.90

4.70

1.01

1.91

7.12

2.44

22.39

200830.77

18.63

7.16

5.05

0.52

2.41

5.62

2.42

21.45

200930.50

17.93

8.42

4.28

0.52

2.68

4.88

2.53

22.48

33. 15. 6.4 5. 0. 2. 6. 1. 20.

Table 3: Total production,teleosts and commercial species

catch (tons) from River Nile at Cairo sector from the period

1990 to 2010, data from the publications of Central System of

General Filling and Statistics (1990-1994) and GADFR (1995-

2010).

Year

Total

produc

tion

Teleos

ts

Tila

piin

esp

ecies

Clar

ias

garie

pinu

s

Bagr

us

Syno

dont

issc

hall

Athe

rina

boye

rigr

ass

carp

1990 765 690 342 226 122 _ _ _

19912002

1485

1485 _ _ _ _ _

1992 977 964 513 117 63 194 78 _

19931705

1671 894 210 153 232

182 _

19941497

1308 771 195 143 199

156 _

19951798

1447 746 200 143 208

165

150

19962560

2322

1282 181 265 179

104

311

19973638

3367

1817 337 349 60

148

697

19983548

2895

2058 362 408 67

368 _

19994452

3679

2277 601 604 197

298 _

20003213

3152

1402 510 633 217

616 92

20016247

5627

1642

1164

1327 725

881

153

20028130

6466

1718

1634

1855

1073

700

186

20037355

6107

1836

1659

1479 898 _

235

2004 751 740 429 192 696 189 _ 30

0 5 4 6 0

20056923

6807

3918

1737 683 187 _

282

20065148

5094

3232 949 538 158 _

217

20073950

3830 850

1316 713 477 _

474

20082244

2089 350 696 409 301 _

333

20092326

2151 397 703 407 293 _

351

20102236

2074 385 625 381 279 _

404

Mean3624

3363

1534 736 546 302 22

4233

SD2182

2087

1137 602 478 271 22

8158

Min. 765 690 342 101 63 60 78 92

Max.8130

7405

4294

1926

1855

1073

881

697

Range

6745

6715

3952

1825

1792

1013

803

605

CV0.60

0.62

0.74

0.81

0.87

0.87

1.02

0.68

Table 4: Total production, Teleosts and commercial species

catch (tons) from River Nile at Assiut sector from the period

1990 to 2010, data from the publications of Central System of

General Filling and Statistics (1990-1994) and GADFR (1995-

2010).

Year

Tota

lprod

ucti

on

Teleos

ts

Tilapi

ine

spec

ies

Clar

ias

garie

pinu

s

Bagr

us s

p.

Syno

dont

issc

hall

Labe

o

Late

s ni

lotic

us

gras

s ca

rp

1990 587 277 70 70 68 69 _ _ _1991 817 409 100 103 103 102 _ _ _

1992 832 410 105 101 102 103 _ _ _1993 925 431 109 111 107 105 _ _ _1994 881 440 121 110 108 101 _ _ _

19951502

1067 169 138 139 121 _ _ 500

19962043

1451 242 214 232 132 _ _ 631

19972756

1845 363 314 348 120 _ _ 700

19982535

1264 400 344 360 160 _ _ _

19993422

1790 545 499 512 234 _ _ _

20003758

3393 512 762 836 311 _ _ 972

20016544

5896 874

1367 1919

1056 _ _ 680

20029000

8160

1219

1907 2673

1533 _ _ 828

20039471

8613

1300

2013 2747

1600 _ _ 953

20044460

3509 544 375 509 289 334

358 1100

20052834

2545 422 219 358 160 126

126 1035

20066677

6225

1257 847 1489 559 690

758 625

20075020

3953 611 423 572 328 378

403 1238

20083528

3528 632 584 801 378 245

568 320

20093718

3718 630 599 787 414 309

621 358

20103982

3982 675 640 823 439 345

648 412

Mean3585

2996 519 559 743 396 183 23

8 527

SD2579

2511 384 563 806 449 152 22

3 387

Min. 587 277 70 70 68 69 101 101 101

Max.9471

8613

1300

2013 2747 160

0 690 758 1238

Range

8884

8336

1230

1943 2679 153

1 589 657 1137

CV0.72

0.84

0.74

1.01 1.09 1.1

40.83

0.94 0.73

Table 5: Total production,teleosts and commercial species catch

(tons) from River Nile at Aswan sector from the period 1990 to

2010, from the publications of Central System of General Filling and

Statistics (1990-1994) and GADFR (1995-2010).

Year To

tal

prod

ucti

Tele

osts

Tila

piin

eBa

grus

sp.

Late

sni

lotic

us

19903181

3181

2860

321 _

19914334

3960

3960 _ _

19924477

3949

3949 _ _

19934504

4125

4125 _ _

19943420

3420

3420 _ _

19953080

2590

2590 _ _

19963299

2998

2998 _ _

19974258

3094

3094 _ _

19984208

2643

2643 _ _

19993229

2656

2656 _ _

20005467

4833

4833 _ _

20014866

4392

3527

401 464

20024500

4137

2898

581 458

20034685

4325

2780

723 822

20045706

5269

3384

882

1003

2005 596 515 329 88 98

20062951

2775

1753

486 536

20072201

2076

1312

369 395

20081677

1582 996

284 302

20091911

1803

1135

324 344

20101154

1089 684

195 210

Mean3648

3253

2663

270 283

SD1505

1311

1216

232 271

Min. 596 515 329 88 98

Max.6258

5269

4833

882

1003

Range

5662

4754

4504

794 905

CV0.41

0.40

0.46

0.86

0.96

Fig. 2 : Total production, Teleosts and Tilapiines catch from River

Nile through 1980-2010 periods.

83141 + sraey84.116 = hctac seniipaliTR 26247.0 =

8.1488 + sraey9.1023 = hctac noitcudorp latoTR 22518.0 =

7836 +sraey 9.2792 = hctac stsoeleTR 29797.0 =

0

00002

00004

00006

00008

000001

000021

000041

0891 5891 0991 5991 0002 5002 0102sraey

hctac stsoeleT

& hctac noitcudorp latoT

0

0005

00001

00051

00002

00052

00003

00053

00004

hctac seniipaliT

latoT stsoeleT seniipaliT

Fig. 3 : Bagrus, Clarias gariepinus and Synodontis schall catch from River Nile through 1980-2010 periods.

Synodontis schall catch = 97.272years+ 52.484R 2 = 0.4084

Bagrus catch = 347.33years + 171.26R 2 = 0.4504

Clarias gariepinu s catch= 614.65years+ 639.45R 2 = 0.6777

0

5000

10000

15000

20000

25000

30000

1980 1985 1990 1995 2000 2005 2010

years

Bagrus catch &

Clar

ias

garie

pinu

s catch

0

1000

2000

3000

4000

5000

6000

7000

Syno

dont

is s

chal

l catch catch

Bagrus sp. Clarias gariepinus Synodontis schall

Fig. 4: Total production, Teleosts and Tilapiines catch from River Nile through 1980-2002 periods.

24711 + sraey1.458 = hctac seniipaliTR 26819.0 =

8.6143 +sraey9.6023 = hctac stsoeleTR 27577.0 =


0

00002

00004

00006

00008

000001

000021

000041

0891 5891 0991 5991 0002

sraey

hctac stsoeleT & hctac noitcudorp latoT

0

0005

00001

00051

00002

00052

00003

00053

00004

hctac seniipaliT


Fig. 5: Total production, Teleosts and Tilapiines catch from River Nile through 2003-2010 periods.

Tilapiines catch = -858.02years + 33332R 2 = 0.2738

Total production catch = -4147.9years + 112838R 2 = 0.5616

Teleosts catch = -4044.4years + 106809R 2 = 0.6221

0

20000

40000

60000

80000

100000

120000

140000

2003 2004 2005 2006 2007 2008 2009 2010

years

Total production catch &T

eleosts catch

0

5000

10000

15000

20000

25000

30000

35000

40000Tilapiines catch

Total Teleosts Tilapiines

Fig. 6: Total production, Teleosts and Tilapiines catch from River Nile at Cairo sector through 1990-2010periods.

Tilapiines catch = 39.536years + 1098.9R 2 = 0.0465

Total production catch = 170.76years + 1745.7R 2 = 0.2358

Teleosts catch = 170.27years + 1490.3R 2 = 0.2564

0

1000

2000

3000

4000

5000

6000

7000

8000

1990 1995 2000 2005 2010

years

total production catch & Teleosts catch

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

Tilapiines catch


Fig. 7: Total production, Teleosts and Tilapiines catch from River Nile at Cairo sector through 1990-2002 periods.

13.915 + sraey40.211 = hctac seniipaliTR 27615.0 =

39.302 - sraey39.854 = hctac noitcudorp latoTR 26218.0 =

88.591 - sraey4.314 = hctac stsoeleTR 24628.0 =

0

0001

0002

0003

0004

0005

0006

0007

0008

0991 1991 2991 3991 4991 5991 6991 7991 8991 9991 0002 1002 2002

sraey

stsoeleT & hctac noitcudorp latoT

hctac

0

005

0001

0051

0002

0052

hctac seniipaliT


Fig. 8: Total production, Teleosts and Tilapiines catch from River Nile at Cairo sector through 2003-2010 periods.

Tilapiines catch = -508.67years+ 4196.8R2 = 0.5533

Teleosts catch = -832.37years + 8190.3R 2 = 0.8475

Total production catch = -858.19years + 8485.9R 2 = 0.8809

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

2003 2004 2005 2006 2007 2008 2009 2010

years

Total production catch & Teleosts catch

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

Tilapiines catch


Fig. 9 : Total production, Teleosts and Tilapiines catch from River Nile at Assiut sector through 1990-2010 periods.


155.76 + sraey81.662 = hctac stsoeleTR 25234.0 =

210.35 + sraey563.24 = hctac seniipaliTR 21864.0 =

0

0001

0002

0003

0004

0005

0006

0007

0008

0009

00001

0991 5991 0002 5002 0102

sraey


0

0001

0002

0003

0004

0005

0006

0007

0008

0009

00001

hctac seniipaliT

stsoeleT seniipaliT latoT

Fig. 10: Total production, Teleosts and Tilapiines catch from River Nile at Assiut sector through 1990-2002 periods.

94.481 - sraey614.97 = hctac seniipaliTR 24397.0 =

7.7121 -sraey2.565 = hctac noitcudorp latoTR 26567.0 =

2.9151 - sraey9.115 = hctac stsoeleTR 21486.0 =

0002-

0

0002

0004

0006

0008

00001

0991 1991 2991 3991 4991 5991 6991 7991 8991 9991 0002 1002 2002

sraey

hctac stsoeleT

& hctac noitcudorp latoT

002-

0

002

004

006

008

0001

0021

0041

hctac seniipaliT


Fig. 11: Total production, Teleosts and Tilapiines catch from River Nile at Assiut sector through 2003-2010 periods.

70.179 + sraey551.74- = hctac seniipaliTR 25221.0 =

3.3876 + sraey78.754- = hctac noitcudorp latoTR 26862.0 =

5.3516 + sraey24.563- = hctac stsoeleTR 21902.0 =

0

0001

0002

0003

0004

0005

0006

0007

0008

0009

00001

3002 4002 5002 6002 7002 8002 9002 0102

sraey


0

002

004

006

008

0001

0021

0041

hctac seniipaliT


Fig. 12: Total production, Teleosts and Tilapiines catch from River Nile at Aswan sector through 1990-2010 periods.

1.2324 + sraey36.241- = hctac seniipaliTR 28925.0 =

5794 + sraey56.021- = hctac noitcudorp latoTR 24742.0 =

8.3044 + sraey26.401- =hctac stsoeleTR 21542.0 =

0

0001

0002

0003

0004

0005

0006

0007

0991 5991 0002 5002 0102

sraey


0

0001

0002

0003

0004

0005

0006

hctac seniipaliT


DISCUSSION

River Nile is considered one of the most important fishery

resources in Egypt. However, most of the commercial fish species

inhabiting the Nile did not have enough attention and research

necessary to develop and manage its fishery resources.

After the construction of Aswan High Dam Gaafer (1992) revealed

progressive decrease in the number of fish, both in species and

quantity. At the present study, the total annual catch of the

different species of fish from the Nile during the period 1980 to

2010 indicated that tilapiines contributed the higher percentage of

the total catch (47.74%) while Clarias gariepinus constituted 16.02%,

Bagrus sp. 8.74%, Lates niloticus 3.26 % and S. schall 2.41% of the total

catch of the River Nile.

Gaffer (1992) found that Tilapiine fishes constituted 61.25% of

the total catch at Aswan segment of the Nile while, Lates niloticus

constituted 13.62% of the total yield , 1.12% Labeo niloticus , 0.75

Bagrus fishes and 1.38% Synodontis schall.

El-Kashief (2002) recorded 57% in tilapia species, 12% in Clarias

lazera, 8% in S. schall and 3% in Labeo niloticus of the total catch of the

River Nile from El-Kanater El-Khairia to Qena.

Mohamed(2005) showed that the annual catch of the different

species of fish from the Nile at Bani-Suef area during 2002

indicated that Clarias lazera contributed the higher percentage of the

total catch of Bani-Suaf area(17.88%) and 15.76% in Bagrus fishes,

15.22% in tilapiines , 11.09% in Lates niloticus and 10.84 in S. schall.

The statistics of catch-effort data from the Nile from 1980 to

2010 showed a reduction trends in catch until it reached the highest

values at 2002 then a gradual decrease in catch occurs. In addition,

by studying the species composition of fishes at different segments

along the River Nile (Cairo, Assiut and Aswan) it was found that

there is a reduction in fish species composition at Aswan segment in

comparison with those found at Cairo segment. This in accordance

with Gaafer (2002) who revealed a progressive decrease in number of

fish, both in species and quantity since he found only thirteen fish

species in the commercial catch at Aswan segment of the Nile.

In conclusion, the studying of the catch and species composition

of the River Nile fishery showed that many fish species are still

dominant while, several fish species are declining and probably

disappearing from the commercial fisheries catch. Since fish are

considered among the most important source of animal protein in

Egypt, the demand for increasing fish production has become a great

necessary due to the rapid growth of its population.

د م�صر صعي� ل� ب�� ي� هر ال�ن� ى ن�� ودة� ف� ة� ال�هامة� ال�موج�� اري�� ج� س�ماك�+ ال�ت) عض� الأ/ د ب�� اة ل�مصي� ج� ت�� ل الأ8 جلي� ت��

ن: ي� صور ح�سي� مان: م�ن� �Bي اسم- ا8 س�امة� م�حمد م�حمود ق�� ى م�كاوى- ا/ ن� دال�ع� ح�مد ع�ي� م�ام ا/ ا8وط س�ي� ام�عة� ا/ ة� ال�علوم- ج�� - ك�لي� وان: سم ع�لم ال�حي� ق��

ت�رة� م�ن: ى ال�ف� د ف� هد ال�صي� ل و ج�� ي� هر ال�ن� ى ن�� ودة� ف� س�ماك�+ ال�موج�� واع الأ/ �Bن عض� ا/ د ب�� ة� ل�مصاي�� ي� ح� ارت�� ات� ال�ي� اي�� ي� pع� ال�ن مي� ح� م ت�� و ح�ن�ى1980ت��د2010 ة� وق�� ي� ون: ع�ام�ًا ال�ماض�� لأن�| لأل ال�ي| اج: ج�� ي� ن�� ة� ل�لأ8 ي� م�ن� ل ال�سلأس�ل ال�ز� جلي� ل�ك+ ت�� ات� وك�د� اي�� ي� pة ال�ن ئ�/ى ل�هد� ح�صا ل ا8 جلي� و ع�مل ت��

لى ج: م�ا ي�� ات�/ ي� هرت� ال�ن� ظ�� :ا/

ت�رة� م�ن: 1 لأل ال�ف� داد ج�� ر� ل ا8 ي� هر ال�ن� س�ماك�+ ن�� د ا/ ر ف�ى2002 وح�ن�ى 1980- م�صي� ت� خ� د الأ/ لأل ال�عق� اض� م�لحوط� ج�� ق� ح� ت�� م ج�دت| ا8 ت�|د . ال�مصي�

ل 2 مي| لطى ي�� س�ماك�+ ال�ي� اج: ا/ ي� ن�� لأن:47.74- ا8 مي| ي� اض� ق�� ي� pس�ماك�+ ال�ق�رم�وط و ال�ن ي�ما ا/ ن� pل ب� ي� هر ال�ن� اج: ال�كلى� ل�ن� ي� ن�� % م�ن: الأ8والى .8.74% و 16.02 % ع�لى ال�ي�

د ك�لًأ3 ًا م�ع ض�ي� ي� pBن ا ج� ت�� اط�ًا ا8 ي� رن�� لطى ا8 س�ماك�+ ال�ي� د ا/ ط ض�ي� ن� ما ي��رن�� ي� ن� pد ب� هد ال�صي� ل و ج�� ي� هر ال�ن� ى ن�� س�ماك�+ ف� د الأ/ ي�ن: م�صي� ة� ب�� د ع�لأق� وج�� - لأ ن��ال . س�ماك�+ ال�س| د ا/ ًا م�ع ض�ي� ي� pاط�ًا س�لن ي� رن�� س و ا8 ي� اض� و ال�لي� ي� pم�ن: ال�ق�رم�وط ، ال�ن

ة� و4 ي� ن�/ ا مي� واض ال�كي� ى ال�ح� ر ف� ت� ع� ا ل�لي� ق� ل ط�ي� ي� هر ال�ن� ى ن�� س�ماك�+ ف� ة� م�ن: الأ/ لف� ت� واع ال�مح� �Bن ع الأ/ ي�³ ور� د و ن�� واج�� سب� ن�� ى ن�� لأف� ف� ت� ح�� د ا8 وج�� - ن��واع �Bن عض� ا/ ون: ال�سمكى ل�ي� ى ال�مخ�ر� ادة� ف� ي�� لى ر� دى ا8 دة� م�ما ا/ دي�� ة� ال�ج� ي� ن/ ي� pروف� ال�ن س�ماك�+ ل�لظ� ة الأ/ ف� ه�د� كي� ل و م�دى ي�� ي� ة� ل�لن� ي� ن�/ ا ي¿� ر� ت� ال�ف�

رى . خ�� واع الأ/ �Bن ون: ال�سمكى ل�لأ/ ى ال�مخ�ر� ض ف� ق� س�ماك�+ و ب�� الأ/

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TREND ANALYSIS OF SOME COMMERCIAL FISHES CATCH IN THE RIVER NILE IN UPPER EGYPT

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