Abstract: The Tidal Link is constructed to dispose off the drainage water from Nawabshah, Sanghar, Mirpurkhas and Badin districts to Shah Samando Creek. It is connected with brackish water lakes belonging to Run of Kuch and Shah Samando Creek of Arbian Sea in District Badin. These lakes were examined in terms of biological life and water quality. The Sonahro and Mehro are saline lakes rich in primary productivity with 114 species of algae, 17 species of aquatic plants and five species of fresh water fish. Among the fishes Cirrhinus mirgala, Channa marulia, Notopterus notopterus, Oreochromis mossambicu's, Rita rita, Wallagoattu were identified and all are commercially important. Water quality revealed , value of pH as 7.7-8.0, conductivity, 2.74-9.97 mS/cm and salinity 1.5-5.9 ppt with a number of nutrients. Pateji and Cholari are brackish water lakes. Majority of algal flora belong to Bacillarophyta, Cyanophyta and Enteromorpha species of Chlorophyta. Beside, 28 species of fish and 8 species of shrimps were identified.
Introduction
In order to decrease water logging and salinity problem in Nawabshah, Sanghar, Mirpurkhas and Badin districts, Left Bank Outfall Drain (LBOD) Project was carried out. The drainage through the Kadhan Pateji Outfall Drain (KPOD) are connected to Tidal Link. The Tidal Link also feeds water to Cholari, Pateji, Sonahro and Mehro Lakes through Cholari Weir. The lake cover an area of about 70 square km. All the lakes are shallow with the depth ranging 2-6 feet. The lakes are located at 25-30 KM east and south of Badin city lying between 24-25°N. Latitude arid 68-69°E. Longitude (Map No. 1). Left Cholari is connected with Runn of Koch. Cholari Right, Pateji, Sonahro and Mehro are connected to Shah Smando Creek Arbian Sea via Tidal Link canal.
Cholari weir serves dual purpose in providing the water from Shah Samando Creek to the lakes arid for the drainage back of the water from the lakes to the Sea. Sonahro and Mehro lakes receives surplus water from the irrigated canals, agricultural lands and water logged area through the drains. These lakes are in natural depression, rich in nutrients which support the biological life. Some limnological work available an the fresh water lakes of Sindh, Kinjhar and Haleji, includes Baqai et al. (1974 a, b), Nazneen (1974, 1980) and Khuhawar et al. (1999). Baker lake (Leghari and Khuhawar, 1999), Hub lake (Iqbal, 1986) Manchar lake (Baig and Khan, 1976; Khuhawar and Mastoi, 1995). The present work examines the biological life and water quality of drains and saline brackish water lakes of District Badin to assess the feasibility of fisheries development.
Materials and Methods
Pateji, Cholari, Sonahro, Mahro (Karoghanghro) lakes were examined during July to October 1997. Plankton samples were collected by using 25 μm plankton net and hand picking method. The plankton samples were preserved and stored in 13.4%) formaline. Aquatic plants were collected manually tram various location. For taking out from the bottom of the lakes a plant grapnel was used.
Samples of various kind of algae were collected manually from shallow and marginal area of the lakes. Epiphytic algae were Scraped off from the leaves and stems of emergent and submerged plants.
Fishes were collected by using hand nets and from the lending centres.
Water sampling was carried out during July to October 1997 with an interval of about two weeks. Time of collection of the sample varied within 11.0 a.m to 6.30 p.m. The temperature of water and air (1m) above the surface varied within 2533.7°C and 25-37°C respectively.
The water samples from Cholari, Pateji, Sonharo and Mehro were collected about 50-100 meters from the side of the lake. The water samples from Sonahro lake (Kara Ghanghro) upto 34 km inside Sonahro lake and 6-12 km towards the Cholari weir were collected from the boat. At each sampling station, boat was stopped and when turbulence created in the water due to the movement of the boat subsided, the water sample was collected.
The water sample was transferred to precleaned 2.5 litre brown glass bottle. The Meyers sampling bottle was allowed to dip to required depth and the rope attached to the open mouth of the bottle was pulled to open the bottle and was filled.
At the time of collection of sample temperature of water and air (1m) above the surcface of water) were taken by mercury thermometer. Transparency was measured by Secchi disk, electrical conductivity and salinity were recorded by WTW LF320 conductivity meter, pH measurements were made on Orion model 420A pH meter.
The total residue was obtained by weighing the material left after evaporation of well mixed sample (100 ml) and drying the residue at 105°C. The filterable residue (TDS) was obtained by, evaporation, the filterate and weighing the material left after drying at 105°C. The samples were analysed for choloride, alkalinity and hardness by titration of their known amounts with standard silver nitrate, hydrochloric acid and E.D.T.A respetively. Dissolved oxygen determination was carried out by Wrinkler's method. Total phosphate, silica and ammonia were determined by spectrophotonmetry (Framan,1981).
Results and Discussion
The Sonahro, Mehro, Cholari and Pateji are brackish water lakes and are inter connected with each other (Map 2).
| Table 1: | Water Chemistry of Drains, Sonharo, Mehro Pateji and Cholari Lakes of District Badin Sindh, Pakistan |
| Table 2: | Aquatic Plants Recorded from Sonharo, Mehro Pateji and Cholari Lakes of District Badin Sindh, Pakistan |
| - absent, present, 4 + Presnet in abundant , +++ dominant | |
| Table 3: | Phytoplanklans and Algae Recorded from Sonahro, Mehra, Pateji and Cholari |
| - absent, 4- present, + i Presnet in abundant +++ dominant | |
Sonahro and Mehro lakes receive surplus water through the drains rich in the nutrients with total phosphate 12-41 μ/L, silica 0.27-0.8 mg/L and ammonia 0.2 mg/L. The water quality assessment for Sonahro and Mehro lakes indicated with pH 7.7-8.5; conductivity, 2.7-9.9 mS/cm; salinity, 1.5-5.9 ppt; hardness as CaCo3 633-1150 mg/L; T.D.S. 1643-6330 mg/L, dissolved oxygen 4.5-7.7 mg/L, total hydrolysable phosphate 40-230pg/L and ammonia 0-0.9 mg/L. (Table 1).
| Map 1: | Map of Tidal Link lakes sowing study area of Badin District, Sindh. (Source: Final Fisheries Report of Tidal Link lakes, Department of Fresh Water Biology and Fisheries University of Sindh, Jamshoro, 1997) |
| Fig. 1: | 1: Oscillatoria vizagapatensis Rao.. 2: Phormidium calcicola Gardner 3: Lyngbya confervoides Ag. 4: Phormidium purpurascens (Kuetz) Gomont. 5: Lyngbya marrensiana Menegh. 6: Johannesbaptisria pellucida (Dickie) Taylor at Drouet. 7: Fungal spore. 8: Oscillatoria limosa 9: Oscillatoria formosa Bory. 10: Lyngbya. majuscula Ham 11: Lyngbya hieronymusii Lemm.12: Lyngbya epiphytica Wille. 13: Xenococcus Kerner' Hansg. 14: Xenococcus acervatus Satchel'. 15: Oscillatoria princeps Vaucher. 16: Calothrix epiphytica West. W. West. 17: Oscillatoria irrigua Kutz. 18.: Ocillatoria limnetica Lemm. 19: Spirulina major Kuetz. 20: Stichosiphon sansibancus (Hieron) Drout et Daily. 21: Chroococcus Iiinneticus Lemm. 22: Microcystis aeruginosa Kuetz. 23: Microcystis flosaqua Kirchn, 24: Merisrnopedia tenussima Lemm. 25: Chroococcus turgidus (Kuetz) Nag. 26: Chroococcus minutus (Kuetz) Nag |
| Fig. 2: | 1: Phacus pleuronectes. 2: Phacus minutu$ (Play fair) pochman. 3: Scenedesmus opoliensis Richter. 4: Scenedesmum armatus (Chodab G.M. Smith. 5: Scenedesmus bijugatus (Turpin) Kuetz. 6: Gloeotaenium loitelsbergerianum Hansgirg, 7: Cosmarium trilobuatum. 8: Scenedesmus armatus var. bicaudatus Chodat. 9: Closterum parvulum Nag. 10: Closterum acerosum, 11: Pediastrum duplex Myen. 12: Euglena acus Ehr. 13: Euglena Sp. 14: Euglena Oxyuris. 15: Cladophora glomerata Kuetz. 16-18: Oedogonium Sp, 19: Stigeoclonium subsecundum Kuetz. 20: Crucigenia tetrapedia (Kirchn/ West. G. S. West |
| Fig. 3: | |
| 1: | Chara zeylinca Kelin Chilldenow. |
| 2: | Chara fibrosa A. Braun 3-5:Derepyxis stokessii Lemm. |
| 6&7: | Derpyxis stokesii var. planticum |
| 8: | Katagny mane pelagica Lemm, |
| 9: | Chlorella valugaris Beij. |
| Fig. 4: | Enteromorpha procera |
| Enteroniorpha salina | |
| E. prolifera | |
| Fig. 5: | 1-5: Compsopogen coe,ruleus iBulbis) Mont x 400 6: Campylodiscus sp. |
| Fig. 6: | 1: Pletirocepsa minor Flansg. 2: Platymonas elliptica G. M. Smith 3: Spirulina subtilissima ICrfetz ex gornont. Microcoleus chihonoplastes Thurel ex Gomant. 5: Ocillaloria formosa Bory. 6: Phormidium bohneri Schrpictle. 7: Gomphosphaeria aponina. 8: Rhizoclonipm heiroglyphicurh Kuetz, 9: Chroococcus minutus. 10: Gloencapsa calcarda Tilden. 11: Oscilinuaria angustissima. 12: Gyrosigma scalporides. 13: Gomphonema. Ghosca. 44:. Nitzschia vermicularis (Kutz) Gum. 15: Meiosira Various Ag. |
| Fig. 7: | 1: Nitella hyalina Agardh. 2-4: Lamprotharniniurn succinatum R.D.W. 5: Cyanostylon rnicrocystoides Geitl. 6: Cosmarium subcostatum Nordst. 7: Cylincirospermum sp. 8: Oocystis eiliptica. 9: Chroococcus turgidus (Kuetz) Nag. 10: Johannesbaptistia pellucida (Dickie) Taylor. 11: Fungal spores. |
| Table 4: | Marine, Fresh Water Fishes and Prawn Recorded from Pateji, Chotail, Sonharo and Mahro Lakes of District Badin Sindh, Pakistan |
Being rich in nutrient, these lakes support a rich plant life. Typha domingensis, Pharagmite communis Scirpus sp. and Fimbristylis sp. are marginal which are used as food by buffalows. They also provide shelter to aquatic birds. AzoIla pinnata, and Lemna minor are the free floating and Ipomoea aqutica, Nyrnphae stellata are rooted with floating leaves, while Hydrilla yerticillata, Ceratophyl/um demersum, Myriophyllum spicatum, Najas major, Najas minor, Potamogeton pectinatus, Potamogeton nodosus were present as sub-merged vegetation. Najas major and Potamogeton pectinatus servied in the saline condition and covered major portion of the lakes. Cambra and Aboal (1992) and Cook (1996) have suggested that P. pectinatus survive in the adverse condition of salinity due to the tuber formation and excessive seed growth. Their seeds and tubers became food of the ducks and other aquatic migratory and local birds (Table 2).
Pistia stratiotes is an important plant found in Serani drains connected to the KPOD.
The Sonahro and Mehro lakes possess brackish water habitates. In which 114 species of algae were identified among these 45 (42%) species belonging to Cyanophyta, 44(33%) species of Chlorophyta, 17(15%) Bacillarophyta. 4(3.5%) species Pyrrophyta, and one specie each of Xanthophyta and Rhodophyta (Fig. 3).
All groups of algae are represented in the form of Phytoplankton. Some of these species have also been identified and reported by Pinko and Mutlag (1982) from Aden near the Yamni coast. The dominant genera were Synechococcus, Merismopedia, Oscillatoria, Gomphosphaeria, Chroococcus, Spirulina, to Cyanophyta, (Fig. 1, 1-26). Euglena, Cosmarium, Ankistrodesmus, Closteriurn, Phacus to Chlorophyta (Fig. 2, 1-19) and Cymbella, Campylodiscus, Cocconeis Melosira, Navicula belonging to Bacillarophyta. Scytonema, Lyngbya, Johannesbaptistia, Calothrix, Katagnymene, Oedogonium, spirogyra, Stigeocolonium, Rhizocolonum and Composopogen coerules, (Fig. 5, 1-5) Cladophora found intermingled with submerged vegetation Chara zeylanica, Chara fibrosa, Lamprothanium succinatum, Nitella hyalina (Fig. 3, 1-2) (Fig. 7, 1-4), alongwith Najas minor, Najas major and Potamogeton species were found over grown with epiphytic species present in abundance.
Cholri and Pateji lakes are brackish water lakes and receives marine water through the Cholari weir at high tides from the Shah Samando Creek via Tidal Link.
| MAP 2: | Maps of Sonahro, Mahro, Cholri , Pateji lakes and Drains of Badin District, Sindh. (Source: Final Fisheries Report of Tidal Link lakes, Department of Fresh Water Biology and Fisheries University of Sindh, Jamshoro, 1997). |
These have pH 8.31, conductivity 11.8-22.2 mS/Cm, hardness 16602362 mg/L, salinity 8-22.2 PPT, dissolved oxygen 4.5-5.7 mg/L, total hydrolyseable phosphate 80-120 pglL; silica 6.2 mg/L and ammonia as a Amonium nitrogen 0-0.5 mg/L. The bottom of the lakes is covered by Cyanophyta. Microcoleus, Chroococcus, Aphanothece, Aphanocapsa and Pleurocapsa minor. Alongwith Rhizoclonium (Fig. 6, 1-8). Enteromorpha salina, E. prolifera and E. intestinalis E. procera Ahl (Fig. 4, 1-3) belong to Chlorophyta, Shameel (1987) and Shamel et al. (1989) have reported similar species for coastal region of Lasbella, Makran of Baluchistan province. These lakes support 28 species of marine fishes, in which 9 species are of commercial value and 19 species are source of protein for poor poeple and food for the poultry feed and 8 species of shrimps were recorded (Table 3, 4).
Acknowledgement
We are deeply indebted to the authorities of Wapda (Water) Wing South Environmental Committee, for funding this project including transport & other facilities throughout the survey.