Occurrence and Abundance of Fish Larvae in the ...

JKAU: Mar. Sci., Vol. 24, No. 2, pp: 15-27 (2013 A.D. / 1434 A.H.) DOI : 10.4197/Mar. 24-2.2

Occurrence and Abundance of Fish Larvae in the restored Mesopotamian Marshlands, Southern Iraq Najah Abood Hussain, Sumaya Mohamed Ahmed* and Laith Faisal Lazem** Dept. of Biology, Coll. Science, Basrah Univ., Iraq * Dept. of Fisheries and Marine Resources, Coll. Agriculture, Basrah Univ., Iraq ** Institute of Teachers, General Directorate of Education in Basrah, Iraq **[email protected] Abstract. Occurrence and abundance of fish larvae in southern Iraqi marshes were studied during 2005 and 2006. Monthly samples of fish larvae have been collected from three southern marshes (Al-Huwayza, Suq Al-Shuyukh and East Hammar).The results showed that the occurrence of fish larvae in the restored marshes exhibited strong seasonality, as the number of larvae increased slightly during February, peaked during March-April period, then decreased in May, and disappeared in June. The survey indicated that Al-Huwayza marsh seemed to be the better spawning habitat comparing with the other two studied marshes. However, larvae of alien species, C.auratus were the most dominant species in 2006 followed by native species L.abu. In 2005 larvae of native species, A.dispar dominated followed by L.abu. It seemed that the peak occurrence of fish larvae accompany more with zooplankton bloom than phytoplankton, especially in 2006. Three groups of larvae emerged, the first consisted of three species (A.dispar, A.mossulensis and A.vorax) shows close relation with zooplankton more than the other two groups. The second group constituted of two species (C.carpio and C.auratus) were more close to phytoplankton. The third group includes three species (L.abu, B.sharpyi and B.luteus) were in the middle level between the first two groups. We can conclude that the southern marshes of Iraq play a vital role in fish conservation and management by increasing aquatic habitat diversity via passive rehabilitation.

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Najah Abood Hussain et al.

Introduction The southern Iraqi marshland represent the richest wetland biotopes in the southwest Asia and Middle East, considered as perfect refuge for riverine, diadromous and coastal marine fishes. The southern marshes were subjected to planned desiccation for more than a decay during the nineties of last century from 1990 to 2003, resulted in disappearance of 93% of original wetlands and eliminated the unique flora and fauna , only small part of Al-Huwayza marsh left that saddles the Iraqi-Iranian border (IMRP, 2006). After inundation in April 2003, the environment started to recover and flourish again after thirteen years of sever desiccation. Richardson and Hussain (2006) showed that the recovery of southern marshes environment on different levels of the biotic huarache was not equal at the same time highlighted the constrain facing these organisms to reestablish again. It seemed that the restored marshes exhibited lower level of productivity of aquatic plants and phytoplankton in comparison with that before desiccation in the 1990s (Al-Hilli et al., 2009 and Hamdan et al., 2010). The southern marshes have been considered as a major source of fishes to the Iraqi people as stated by Al-Daham (1988). The environment of the southern marshes has been known before desiccation as excellent spawning and nursery ground for many riverine and migratory marine species. The main goals of this work are to recognize, if the restored marshes retain their original role as spawning grounds for the native fish and exotic species. Identification of the spawning species from the occurrence of their larvae, recognizing the spawning season and have ideas about the environmental conditions suitable for spawning season and assessing relation with flourishing seasons of phytoplankton and zooplankton blooms with fish larval occurrence. Materials and Methods Monthly samples of fish larvae have been collected from three monitored southern marshes (Al-Huwayza, Suq Al-Shuyukh and East Hammar) during 2005 and 2006 (Fig. 1). Sampling was conducted throughout daytime using conical plankton net (one-meter length, upper opening of the net is 50 cm, mesh size 300µm). The net was set

Occurrence and Abundance of Fish Larvae in the restored Mesopotamian …

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horizontally from an anchored boat heading against the direction of the current. Ichthyoplankton samples then were preserved in 10% formalin solution. A wooden quadrate 50×50 cm, was used for separating aquatic plants that gathered with fish larvae. The quadrate is fallen on the aggregation of floating and emerging plants then gathering these plants, which were present inside the quadrate and put in plastic bags. Some environmental factors were measured during sampling time, which include water temperature, salinity, pH, total suspended solids (TDS) and dissolved oxygen using YSI 556 MPS apparatus. The specimens have been examined in the laboratory under binoculars microscope and identified according to Fuiman et al. (1983) and Pyka et al. (2001). The community ecology program CANOCO 4.5 Package (Version 4.5; Cajo J. F. ter Braak, 2004) was used to assess the factors that influence the ordination.

1

3 2

Fig. 1. Southern Iraqi marshes showing the sampled marshes. (1: Al-Huwaza; 2: East Hammar; 3: Suq al-Shuyukh )


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Results Abiotic Factors The occurrence of fish larvae were noticed when the water temperatures ranged between 13°C in February to 25°C in April of 2005 and 2006. The salinity ranged during spawning season from 0.77 to 1.6 ‰ in both years, however, dissolved oxygen fluctuated between 8.3-12.0 mg/l. On the other hand, pH ranged 7.2-8.4. Water depth ranged 2-3, 3-5 and 2-4 meter in Suq Al-Shuyukh, East Hammar and Al-Huwayza, respectively. Seasonal Occurrence of Fish Larvae Occurrence of fish larvae in the restored marshes exhibited strong seasonality. The numbers of larvae increased slightly during February and peaked during March-April period, then decreased in May, to disappear in June. On the other hand, in Al- Huwayza marsh the number of larvae increased in March, reached the peak in April, and decreased rapidly in May, As for Suq Al-Shuyukh marsh, a similar occurrence of fish larvae occurs. In addition, occurrence peak in East Hammar occurred in March and then decreased largely in April till May. In 2006, the highest number of larvae (402 larvae) was collected during April in AlHuwayza marsh and the highest number of eggs (500) was collected in March in Suq al Shuyukh. In 2005, the same pattern were observed but in lower magnitude in both marshes. In East Hammar, that peaked larval occurrence (234) happened earlier in March. Fish larvae disappeared completely in June in the three sampled marshes (Table1). Table 1. Number of fish larvae and eggs collected from Suq al-Shuyukh, East Hammar and Al-Huwayza marshes during 2005 and 2006. Marsh

2005

2006

Huwayza

Suq al-Shuyukh

Huwayza

Suq al-Shuyukh

East Hammar

February

-

-

-

-

-

March

6

10

126

500 fish egg

234

April

29

38

402

25 fish egg

80

May

-

-

140

-

-

June

-

-

-

-

-

Total No.

35

48

668

525

314

Month


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Examination of Spawning Activity The composition of fish larvae species in the restored marshes belongs mainly to family Cyprinidae with dominance of Barbus species. Larvae of alien species (Carassius auratus) were the most dominant species with highest larval abundance (481 larvae) in 2006 followed by native species Liza abu (105 larvae). Moreover, in 2005 native species, Aphanius dispar was dominated (37 larvae) followed by Liza abu (14). Changes in occurrence have been observed for most resident species, where data in Table 2 exhibit the slow return of native species especially those which belong to genus Barbus to the restored marshes. Types of Larval Species In the present study, two types of larvae were recognized: 1) Six native species (L.abu. A.mosullensis, A.vorax, B.luteus, A.dispar and B.sharpeyi) belong to three families; Cyprinidae, Cyprinodontidae and Mugilidae. 2) two alien species (C. carpio and C. auratus) belong to family Cyprinidae (Table2). The percentage of native larval species was 66.6% in 2005 and increased to 75% in 2006; alien species formed 33.3% and decreased to 25% in 2005 and 2006 respectively. The number of native spawned increased from four in 2005 to six in 2006, Numbers of alien spawners were the same in both years (Table 2). Table 2. Number and (percentage) of larval species collected from the three southern marshes (Al- Huwayza, Suq Al-Shuyukh and East Hammar) during 2005 and 2006. Ecological status Cyprinidae Carassius auratus common Cyprinodontidae Aphanius dispar common Mugilidae Liza abu common Cyprinidae Alburnus mossulensis common Cyprinidae Aspius vorax common Cyprinidae Cyprinus carpio common Cyprinidae Barbus luteus common Cyprinidae B. sharpyi occasional Number and (percentage) of Native species Number and (percentage) of Alien species Total No. Species Unidentified larvae Total No. larvae Family

Species

2005

2006

Kind

12 (14.4%) 37 (44.5%) 14 (16.8%) 11 (13.2%) 6 (7.2%) 3 (3.6%) 4 (66.6%) 2 (33.3%) 6 83

481 (49%) 70 (7.1%) 105 (10.7%) 76 (7.7%) 39 (3.9%) 45 (4.5%) 22 (2.2%) 16 (1.6%) 6 (75%) 2 (25%) 8 128 982

Alien Native Native Native Native Alien Native Native

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Relative Abundance and Ecological Indices The relative abundance of fish larvae in 2005 was different from 2006. The most abundant species in 2005 was A.dispar (44.5%) followed by L abu (16.8%). In 2006, C.auretus was the most abundant (49.0%) followed by L abu (10.7%). Diversity index (H) during 2006 was higher (1.719) in comparison with 2005 (1.505). Richness Index (D) value in 2006 was slightly higher (0.743) than 2005 (0.717). Evenness Index (J) was 0.935 during 2005 and decreased to 0.782 during 2006. However, the marsh area exhibited higher larval diversity (Fig. 2).

Fig. 2. Ecological indices: Diversity (H), Richness (D) and Evenness (J) of fish larvae from Al- Huwayza, Suq Al-Shuyukh and East Hammar marshes during 2005-2006.

Relation Between Phytoplankton, Occurrence of Fish Larvae

Zooplankton

Blooms

and

Figure 3 showed a positive correlation between phytoplankton and zooplankton productivity, with occurrence of fish larvae during March to May 2005 and February to April 2006. Including spring and early summer season (months) conceding with spawning season of resident fish species in the southern marshes. The peak occurrence of fish larvae concedes more with zooplankton bloom than phytoplankton especially in


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2006, while in 2005 the peak and the blooms seemed to happen about at the same time.

Fig. 3. Productivity blooms of phytoplankton, highest growth zooplankton with peak occurrence of fish larvae from Al- Huwayza, Suq Al-Shuyukh and East Hammar marshes. Phytoplankton data from Hammadi et al. (2007) and zooplankton data from Al-Sodani et al. (2007).

Relation Between Biotic and Abiotic Factors and Occurrence of Larval Fish Species The relationships between fish larvae occurrence, biotic (zooplankton and phytoplankton) and abiotic factors (TDS and pH) reveal strong relations. Three groups of larvae emerged, the first consisted of three species (A.dispar, A.mossulensis and A.vorax) showed close relation with zooplankton more than the other two groups. The second group consisted of two species (C.carpio and C.auratus) were more close to phytoplankton. The third group includes three species (L.abu, B.sharpyi and B.luteus) were in the middle between the first two groups. Factors like salinity, water temperature and BOD were more close to effect phytoplankton than zooplankton (Fig. 4).


0.8

22

PO4 DO

NO3

CCA 2

Zoo

A.dispar TDS BOD W.Tem. Sal.

C.carpio

A.mossulensis pH C.auratus

L.abu A.vorax B.sharpyi B.luteus

-1.0

Phyto

-0.6

CCA1

1.0

Fig. 4. The relationship between the occurrence of fish larval species with phytoplankton and zooplankton and abiotic factors (water temperature, salinity, BOD, pH, TDS, DO, NO3 and PO4) from Al-Huwayza, Suq Al-Shuyukh and East Hammar marshes.

Discussion The fish habitat of the southern marshes could be described as limnophilic derived mainly from the lower reaches of Tigris and Euphrates rivers with few eurytopic strays (Mohamed et al., 2008; and Hussain et al., 2009). The fish community of the southern marshes marked by the dominance of two fish species, the first was native (L. abu) and the second was alien (C. auratus) as indicated by Hussain et al. (2008), Mohamed et al. (2008) and Hussain et al. (2009). In the present study, increasing in number of fish larvae collected in restored marshes in 2006 was noticeable to that of 2005, which reveals that spawning activities were low during 2005 in comparison with the spawning season of 2006, because of environmental recovery and increase of productivity. Consequently, the restored marshes offer again suitable environment and sites for native and exotic species to spawn.


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Spawning activity covered the three monitored marshes in 2006 and partially in 2005 as evident of improving of environment of restored marshes. This is because higher water flow increase inundation of floodplain areas, which provide more spawning ground, rearing and foraging sites, since 2006, which was considered as wet year. Ali et al. (2005) collected many fish larvae in East Hammar marsh especially L.abu and many Cyprinidae spp. Proving that the restored environment of the southern marshes offer a suitable microhabitat for native and alien to spawn and cover food requirements for marine migratory juveniles. Variations in spawning activities between the studied southern marshes were may be due to wetlands environmental setting and geographical situation of each marsh, i.e. Al-Huwayza is freshwater non-tidal marsh, Suq Al-shuyukh is oligosaline non-tidal marsh and East Hammar is semidiurnal tidal mesosaline marsh. On the other hand, Al-Huwayza is 100 km to north from the other two marshes. It has been noticed that spawning happened in East Hammar earlier than the other two marshes. However, each marsh seemed to have its own timing for first occurrence of larvae, which could be due to the prevailing environmental factors. The survey indicated that Al-Huwayza marsh seemed to be the best spawning habitat for freshwater fish species comparing with the other studying marshes, could be related to several reasons: 1) Al-Huwayza was the only marsh not desiccated completely i.e. natural fish stock existed, 2) environmental conditions suitable prevailing lower salinity (0.6 ppt) and 3) suitable primary productivity (IMRP, 2006). Daga et al. (2009) stated that rich supply of food in marsh area might support the high diversity and abundance of fish larvae. Besides, Sommer et al. (2004) pointed out that higher diversity and richness of species could be related to a wider variety of habitat types and greater hydrologic variation. However, higher species diversity may be explained by higher habitat diversity (Kaemingk et al., 2007). Range of temperature between 13 and 25 °C controls the spawning season in the southern marshes. The same results reached by Brinda et al. (2010). In the marshes ecosystem where temperature influences the spawning season, the abundance and diversity of fish larvae. Salinity also is one of the prime environmental factor that influences the abundance and diversity of fish larvae that in turn was influenced by fresh water

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inflow as stated by Meng and Matern (2001). Few larvae of some commercial species (B. sharpeyi, B. luteus and A. vorax) were collected indicating that restoration was progressing and the marshes are retaining their original role as important spawning ground for many commercial fresh water species. The high spawning activity of C. auratus in the restored marshes, this alien species achieve greater success in colonization of the marshes habitat because of their short life cycle and high fecundity (Al-Noor, 2010) and may be due to the absence of its natural enemies and local diseases in this microhabitat. However, fish larvae found in the wetland seems to be suitable for their ecological demands (Nellen and Sohnack, 1974) and their distribution in the inland waters may be blessed by patterns of behavior. The presence of high cover of submerge aquatic plants such as Certophyllum demersum, valisanaria spiralis and Potamotageton spp. in the marsh area (Al-Abbawy and Al-Mayah, 2010) provides a suitable shelter and spawning ground for fish. We can conclude that the southern marshes of Iraq play a vital role in fish conservation and management by increasing aquatic habitat diversity via passive rehabilitation. Acknowledgment Our thanks and gratitude goes to ARID project/Development Alternative International /USAID for their valuable assistance, planning and execution of the Iraqi marshes project without their financial funding this work would have never been achieved. References Al-Abbawy, D.A.H. and Al-Mayah, A.A. (2010) Ecological Survey of Aquatic Macrophytes in Restored Marshes of Southern Iraq during 2006 and 2007. Marsh Bull, 5: 177-196. Al-Daham, N.K. (1988) Development of fisheries in the marshes, southern of Iraq, obstacles and solutions, The Arab Gulf, 20(2): 85-97 (in Arabic). Al-Hilli, M.R., Warner, B.A., Asada, T. and Douable. A. (2009) An assessment of vegetation and environmental controls in the 1970s of the Mesopotamian of southern Iraq. Wetlands Ecol. Mange, 17: 207-223. Ali, T.S., Mautlak, F.M. and Khadaer, M.T. (2005) Preliminary indication on rehabilitation of marshes on the biology of the fish assemblage (abstract) 1p. First Scientific Conference on rehabilitation of the Ahwar (Marshes) of southern Iraq. Marine Science center and ICF, Basrah Univ. Iraq. 73p. Al-Noor, S.H. (2010) Population status of gold fish Carassius auratus in restored East Hammar marsh, southern Iraq. JEUK. Mar. Sci., 21(1): 65-83.


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Al-Sodani, H.M., Abed, J.M., Al-Essa, S.A.K. and Hammadi, N.S. (2007) Quantitive and qualitative study on zooplankton in restored southern Iraqi marshes. Marsh Bull., 2(1): 4363. Brinda, S., Srinivasan, M. and Balakrishnan, S. (2010) Studies on diversity of fin fish larvae in Vellar Estuary, southeast coast of India. World Journal of Fish and Marine Sci., 2(1): 4450. Daga, V.S., Gogola, T.M., Sanches, P.V., Baumagartner, G., Piana, P.A., Gubiani, E.A. and Delariva, R.L. (2009) Fish larvae assemblage in two floodplain lakes with different degrees of connections to the Parana River, Brazil. Neotropical Ichthyology, 7(3): 429-438. Fuiman, L.A., Conner. J.V., Lathrop, B.F., Buynak, G.L., Snyder, D.E. and Loos, J.J. (1983) State of the art of identification for Cyprinid fish larvae from Eastern North America. Transection of American Fishery Society, 112: 319 -332. Hamdan, H.A., Asada, T., Hassan, F.M., Warner, B.G., Douabul, A., Al-Hilli, M.R. and Alwan, A.A. (2010) Vegetation response to re-flooding in the Mesopotamian wetlands, southern Iraq. Wetlands 30: 177-188. Hammadi, N.S., Jassim, A.Q. and Al-Sodani, H.M. (2007) Occurrence and seasonal variations of phytoplankton in the restored marshes of southern Iraq. Marsh Bulletin, 2(2): 96-109. Hussain, N.A., Saoud, H.A. and Al-Shami, E.J. (2008) Species composition and Ecological indices of fishes in the restored marshes of southern Mesopotamia. Marsh Bull., 2(1): 1731. Hussain, N.A., Mohamed. A.R.M., Al Noor, S.S., Mutlak, F.M., Abed, I.M. and Coad, B.W. (2009) Structure and ecological indices of fish assemblages in the recently restored AlHammar Marsh, southern Iraq. BioRisk, 3: 173-186. IMRP. (2006) Iraq marshland restoration program. Final report. Edited: Reiss P. and Farhan, A. DAI/USAID. Development Alternative Internationl.525pp. Kaemingk, M.A., Greab, B.D., Hoagstrom, G.W. and Willis, D.W. (2007) Pattern of fish diversity in a mainstream Missouri River reservoir and associated delta in south Dakota and Nebraska, USA. River Research Application, 23: 786-791. Meng, L. and Matern, S.A. (2001) Native and introduced larval fishes of Suisun marsh Califorina: The effect of fresh water flow. Transaction of American Fishery Society, 130:750-765. Mohamed, A.R.M., Hussain, N.A., Al Noor, S.S., Mutlak, F.M., Al-Sudani, I.M., Mojer, A.M. and Toman, A.J. (2008) Fish assemblage of restored Al-Hawizeh marsh, Southern Iraq. Ecohydrology & Hydrobiology, 8: 375-384. Nellen, W. and Sohnack, D. (1974) Sampling problems and methods of fish eggs and larvae investigations with special reference to inland water. Symposium on Methodology for the survey, monitoring and appraisal of fishery resources in lakes and large rivers. FAO Technical paper No.23. Pyka, J., Bartek, R., Szczerbowski, A. and Epler, P. (2001) Reproduction of gatan (Barbus xanthopterus), Shabbout (Barbus grypus) and Bunni (Barbus sharpeyi) and rearing stocking material of these species. Arch. Pol. Fish, 9(1): 235-246. Richardson, C.J. and Hussain, N.A. (2006) Restoring the Garden of Eden: An ecological assessment of the marshes of Iraq. Bioscience, 56(6): 477-489. Sommer, T.R., Charrell, W.C., Kurth, R., Feyrer, F., Zeng, S. and Oleary, G. (2004) Ecological patterns of early life stages of fishes in a Large River floodplain of SanFrancisco estuary. American Fishery Society Symposium, 39: 111-123.

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