• Accumulation of trace metals in some benthic invertebrate and fish species revelant to their concentration in water and sediment of lake Qarun, Egypt.

      Fishar, M.R.A.; Ali, M.H.H. (National Institute of Oceanography and Fisheries, 2005)
      Concentrations of major metals (Na, K, Ca, Mg) and some trace metals (Fe, Zn, Mn, Ni, Cu, Co, Pb, Cr, Cd) were determined in water, sediment, benthos and some common fish species from Lake Qarun. Water and sediment samples were collected from seven stations where, the benthos and fish species were collected from three sites representing east, middle and west of the lake. Distribution of studied metals showed that, east part generally had higher contamination than west one which may be attributed to the impact of pollution sources in this area which coming from El-Batts Drain and pumping station in the east part. Mollusca and Crustacea especially Barnacles have the highest concentrations of most heavy metals measured more than Polychaeta which make them suitable candidates to be used in biomonitoring surveys of Lake Qarun. The concentrations of heavy metals in fish samples indicate that Solea sp.and Mugil sp. seemed to be more contaminated than Tilapia sp. which attributed to their feeding behavior. Bioaccumulation factor values showed that the trend of accumulation of most metals was as follows: Mollusca > Crustacea > Annelida > Solea sp. > Mugil sp. > Tilapia sp.
    • Active biological materials inhibiting tumor initiation extracted from marine algae

      Mostafa, M.H.; Ibrahim, A.M.M.; El-Masry, M.H.; El-Naggar, M.A. (Alexandria : National Institute of Oceanographic and Fisheries, 2005)
      Ethanol extraction of seventeen algal species from 35 different samples collected from the coastal area of Abou-Qir, Egypt, South East of the Mediterranean Sea Coast, was conducted. The aim was to obtain natural products from the algal extracts which have significant biologically active algal compounds. The collected algae showed a wide variation in their occurrence during the period of collection. Thirty five extracts representing different seasonal growths of 17 marine algal species were tested for antitumorigenic activity. Tests performed were the toxicity bioassay using Brine shrimp Artemia salina and the anti-tumor bioassay against Agrobacterium tumefaciens on potato discs. Codium tomentosum (winter); Jaina rubens (summer) and Padina pavonia (winter) displayed relatively high activity
    • Analysis of wave observations and wave transformations in Abu-qir, Egypt.

      Sharaf El-Din, S.H.; Abdallah, A.M.; Shereet, S.M. (National Institute of Oceanography and Fisheries (NIOF), 2006)
      Wave observations taken during 1986 in Abu-Qir Bay were statistically analyzed to calculate the wave parameters describing the sea state (significant wave height, wave period and predominant direction). On both sides of Rosetta promontory, the transformed wave parameters at break line (breaker height, breaker depth and crest angle) were calculated in terms of the predominant values of the significant wave height, period and direction using ACES software package. Breaker type and closure depth along Rosetta coast were also predicted. Generally, the wave effect in the bay was varying in intensity and direction in accordance with the prevailing wind. The average annual wave height and period are about 0.94 m and 6.5 s, respectively. Throughout the year, the predominant waves come from the NW direction (42%). Waves with significant height of about 4 m and period of about 11 s were infrequently observed during winter and summer gales. The wave characteristics at breaker line on both sides of Rosetta promontory are approximately similar. Generally, most of the waves along Rosetta coast break at about 1.7 m depth with a breaker height of about 1.5 m. The surf similarity parameter (0) was found to be equal 0.16, predicting that the spilling breaker predominates along Rosetta beaches. The closure depth (dc) associated with the extreme wave conditions along Rosetta coast during 1986 was estimated to be equal 9.3 m, predicting a seaward limit of littoral transport to lie at about 0.5 km from the shoreline.
    • The anthropogenic effluents of the human activities on the red sea coast at hurghada harbour (case study)

      Madkour, H.A.; Dar, M.A. (National Institute of Oceanography and Fisheries, Egypt, 2007)
      The heavy metal accumulations in the seawater, coral reefs and two effective fractions of underlying sediments (<0.125mm and < 0.063mm) were studied in the coastal and tidal flat zones at the main shipyard near of Hurghada Harbour. The area of investigation is very worse whereas, it is considered tailing outlet for both solid and liquid influents of many human activities in/and surrounding the harbour. The solid phases are of construction remains, paint remains, iron pipe rusts, hydrocarbons, plastic bags, metal and wood remains as well as the artificially conglomerate stones that thrown in the in the marine area. The liquid phase is restricted in the continuous brine water draining to the sea from a huge desalination plant (Capacity 5000 cubic meters of freshwater daily) and the bilge water of the boats cooling engines in the mooring zone inside the shipyard marine area. The recorded metals show significant declination seaward in both seawater and sediments. The highest values of Fe, Mn, Zn, Cu, Pb, Ni and Cd in the seawater were recorded at the outlet point of the desalination plant pipeline while the highest values in the sediments were recorded at the beach zone whereas the dumped materials were concentrated. The finest fraction sediments (<0.63mm) recorded high concentrations of the toxic metals; Zn, Cu, Pb, Ni and Cd than the coarsest one. Pb in sediments recorded high reading in the boat mooring zone in the two sediment fractions relative to the beach zone and inside the sea. The recorded coral reefs are new generations (recruits) mostly of the massive forms. These corals were growing over; conglomerate stones, rusted iron plates, plastic remains and car tires dumped to the zone. The metal concentrations in these corals are high relative to their age and the recorded metals in world. This study indicated that some coastal activities as; the shipyards and desalination plants are environmentally antagonistic and must be monitored continuously in order to decrease their effluents to the tidal flat zones. Also, it is obvious that the new coral generations are able to accommodate with the inconvenient conditions.
    • Assessment of heavy metals and nonessential content of some edible and soft tissues

      Ahdy, H.H.H.; Abdallah, A.M.; Tayel, F.T. (National Institute of Oceanography and Fisheries, Egypt, 2007)
      The level concentrations of heavy metals (essential and nonessential) were measured in different marine biota including cephalopoda, bivalve, crustacean and fish. The results reveal that these organisms show more or less the same order of distribution for each of the metals studied. The average concentrations of heavy metals exhibited the following decreasing order: cephalopoda > bivalve > crustacean > fish. The levels of metals in all studied samples are still comparable to those in their corresponding in the Mediterranean Sea. K (98-181μg/g) and Ca (547-1472 μg/g) were present at the highest concentrations in all investigated samples. Octopus and Sepia do not follow the general pattern. The highest value of Metal Pollution Index (MPI) in cephalopod was recorded in octopus (9.55) followed by sepia (7.62). Among investigated bivalve, the highest values of MPI were recorded in Mactra coralline (2.87).
    • Assessment of some heavy metals, major cations and organic matter in the recent sediments of Bardawil Lagoon, Egypt

      Abdo, M.H. (Alexandria: National Institute of Oceanographic and Fisheries, 2005)
      The aim of the present study is to gather detailed information on the distribution and concentration levels of some heavy metals (Fe, Mn, Zn, Cu, Pb & Cd), major cations (Ca,Mg, Na & K), in addition to organic matter in the Bardawil lagoon sediments during four successive seasons during (2001-2002). The different metals concentrations could be arranged in descending order as follows: - Ca> Na> Fe> Mg> K> Mn> Cu> Zn> Pb> Cd.
    • bathymetric chart of alexandria wastern harbor

      El-Geziry, T.M.; Abd Ellah, R.G.; Maiyza, I.A. (National Institute of Oceanography and Fisheries, Egypt, 2007)
      Alexandria Eastern Harbor is a shallow, protected, semi-enclosed, circular basin. It is connected to the Mediterranean Sea through two openings: El-Boughaz (main) and El-Silsila. New data, from a recent bathymetric survey in the Harbor, is used to build up its bathymetric chart. The bottom of the Harbor slopes gradually seawards, with an average depth of 5m inside the Harbor. The study build up Alexandria Eastern Harbor new bathymetric chart, will be a useful tool to follow-up the problems of the harbor and to propose suitable solutions. Recommendations are set in the end of the study to activate the self recovery (by the Harbor water body) to preserve and recover the situation of Alexandria Eastern Harbor.
    • Bioaccumulation of mercury in some marine organisms from Lake Timsah and Bitter Lakes (Suez Canal, Egypt)

      El-Moselhy, K.M. (National Institute of Oceanograhy and Fisheries (NIOF), 2006)
      The present work is devoted to determine the level of total mercury in the different tissues of fish Mugil seheli, crab Portunus pelagicus, shrimp Metapenaeus stebbingi, and bivalves Paphia undulata and Gafrarium pectinatum collected from Lake Timsah and Bitter Lakes during spring 2003. In addition, factors affecting the accumulation of mercury in these organisms were studied. Levels of Hg in the edible parts of the investigated organisms showed the ranges 2.62 – 25.45 and 0.94 – 7.94 ng/g wet wt. in fish, 16.02 – 117.26 and 9.86 – 64.18 ng/g wet wt. in crab, 4.55 – 14.67 and 5.76 – 15.58 ng/g wet wt. in shrimp, and 1.06 – 36.31 and 5.38 – 69.59 ng/g wet wt. in bivalves from Lake Timsah and Bitter Lakes, respectively. High accumulation of Hg was recorded in Lake Timsah organisms which receives wastewaters from different polluted sources. Also, high concentration of Hg was detected in the internal organs of the organisms, especially liver compared with a lower one for the edible tissues. Regression curves and ANOVA analysis were used to study the effect of growth rate, species, sex and sites variation on the accumulation of mercury in the edible parts of the studied organisms. The results obtained from the regression curves and inter-spatial variation indicated that the bivalve Paphia undulata could be used as bioindicator for mercury pollution.
    • Biodegradation kinetics of bromoxynil as a pollution control technology

      Askar, A.I.; Ibrahim, G.H.; Osman, K.A. (National Institute of Oceanography and Fisheries (NIOF), Egypt, 2007)
      Nonpoint source (NPS) pollution from agriculture is the leading source of impairment to Survey Rivers and lakes. Pesticides are one of the major NPS pollutants that result from agricultural activities. Among those pesticides, is Bromoxynil (BRMX) which is a widely used herbicide. The present study was carried out to determine the capability of selected biological control agents to degrade BRMX at different incubation periods. Microbial degradation of BRMX at the rate of 100 ppm in pure liquid culture media of either seven isolates of bacteria; Azotobacter chroococcum, Azospirillium barasilense, Klebsilense pneumoneae, Pseudomonas cepacia, Pseudomonas fluoresences, Bacillus subtilis, and Bacillus polymyxa or two isolates of fungi; Trichoderma viride and Trichoderma harzianum has been determined at different time intervals using high performance liquid chromatography (HPLC) with UV detection, and solid phase extraction (SPE) technique. A biphasic model was assumed in order to carry out the statistical study of the loss of BRMX from the media enriched with either bacteria or fungi. The results showed that, the percentages of residual amount of BRMX from media enriched with bacteria ranged from 29.51 -71.94, 18.89-43.88, 9.82-35.07, 3.47-31.90 and 1.80-19.24% after 3, 7, 14, 21 and 28 days of incubation, respectively. On the other hand, the residual amount of BRMX from media enriched with fungi ranged from 45.61-60.26, 21.25-30.56, 6.48-20.63, 1.25-10.49 and 0.63-1.56% after 3, 7, 14, 21 and 28 days of incubation, respectively. The data indicate that there was a faster rate of BRMX loss in the first phase than the second one. This is clearly reflected in the t1/2 values. Therefore, it is recommended to use these microorganisms as biological control agents for the integrated pest management (IPM) programs to reduce agricultural non point source (NPS) pollution to prevent pesticides from reaching ground and surface water.
    • Biology and toxicity of the pufferfish Lagocephalus sceleratus (GMELIN, 1789) from the Gulf of Suez

      El-Ganainy, A. A.; Sabrah, M. M.; Zaky, M. A. (2006)
      Some biological aspects of the pufferfish Lagocephalus sceleratus were studied and correlated with the toxicity of the fish. A sample of 176 fish with total lengths ranging from 18.5 to 78.5 cm were collected from commercial catches at the Attaka fishing harbor between October 2002 and June 2003. Length weight regression parameters for males, females and all individuals were estimated. Modal progression analysis output indicates ten distinct age groups. The parameters of the von Bertalanffy's growth model were L∞ = 81.1 cm and K = 0.26 per year. The overall sex ratio of males to females was 1: 1.3. The spawning takes place during summer and the size at which 50% of fishes are mature is 42.1 cm for males and 43.3 cm for females. Analysis of the diet composition showed that the fish is carnivorous and the maximum feeding intensity was attained in April. The toxicity of the gonads of twenty five specimens in different sexual maturity stages was assayed. The results showed that the highest toxicity scores were recorded during April, May and June for both sexes during the spawning season. The highest toxicity scores were recorded at the spawning stage of maturity (3500 MU/g for males and 3950 MU/g for females). While most of the specimens in maturity stage II (developing stage) were found non toxic.
    • Cell culture from two red sea benthic invertebrates: a case study on the soft octocorals dendronephthya klunzingeri and anthelia glauca

      Ammar, M.S.A.; Emara, A.M.; Perovic, S.; Wiens, M.; Billinghurst, Z.; Müller, I.M.; Müller, W.E.G. (National Institute of Oceanography and Fisheries (NIOF), Egypt, 2007)
      Primmorphs were obtained from single cells of both coral species Dendronephthya klunzingeri and Anthelia glauca following incubation for three or four days during 2001. Both ultraviolet light (UVB; peak of emission of 320 nm) and visible light (wavelength between 400 and 520 nm with a maximum at 480 nm) were applied to the primmorphs as stressors. The following incubation probes have been isolated from D. klunzingeri and were used to monitor the expression of the respective genes in the homologous cell system; the heat-shock protein HSP90 (to monitor general stress responses), the histone H4cDNA (to monitor the cell cycle/proliferation) and the UVS-related protein (response to ultraviolet light) from D. klunzingeri. The data show that the steady state level of HSP90 expression is only upregulated at low level of exposure to UVB (30 J/cm2), while at stronger irradiation the expression level decreases. The expression of the histone H4 gene is blocked following exposure to UVS. Interestingly, in the absence of UVB no transcripts of UVS-related protein can be visualized. However, after exposure of the primmorphs with 30 to 300 J/cm2 a strong upregulation of the expression of the UVS-related gene is seen. The response of the primmorphs to visible light is distinct to that following exposure to UVB. The expression of the gene for histone H4 is significantly upregulated following exposure to UVB, while no expression of the gene UVS-related protein can be detected. It is concluded that, the primmorph system is useful to assess potential nature and anthropogenic disturbances on coral cells.
    • Comparative study on octopus vulgaris (cuvier, 1797) from the mediterranean and red sea coasts of egypt

      Riad, R.; Gabr, H.R. (National Institute of Oceanography and Fisheries (NIOF), Egypt, 2007)
      Specimens from common octopus, Octopus vulgaris captured from the Red Sea and Mediterranean Sea showed significant differences in four of seven morphometric measurements .These differences are sufficient to recognize the populations of this species in the two habitats. The computed length-Wight relationship and condition factor for common octopus in both areas showed that representatives of this species from the Red Sea are heavier than those captured from the Mediterranean Sea for the same length group. Moreover, the natural mortality coefficient of Mediterranean representatives was comparatively higher than for the Red Sea octopus. This shows that the environmental conditions in the Red Sea are more suitable for O. vulgaris than in the Mediterranean Sea.
    • Determination of persistent organic pollutants in water of new Damietta harbour, Egypt

      Hamed, M.A.; Said, T.O. (2006)
      Persistent organic pollutants (POPs) which include chlorinated pesticides and petroleum hydrocarbons were determined in water samples collected from Damietta Harbour during 2005. Concentration of total pesticides ranged from 0.02 to 0.07 ng/L and from 1.09 to 201.82 ng/L during winter and summer seasons, respectively. The increasing order of total pesticides was: THCHs < TC < total DDTs with concentrations ranged from 0.004-3.20 ng/L, 0.001-3.93 ng/L and 0.002-194.68 ng/L, respectively in the area of study. The average concentrations of total petroleum hydrocarbons were below the admissible environmental levels. They ranged from 2.17-72.89 µg/L and from 5.67-87.56 µg/L during January and July 2005, respectively. However, concentrations of PAHs were below the detection limit in the present study.
    • Distribution and long-term historical changes of zooplankton assemblages in lake manzala (south mediterranean sea, egypt)

      Mageed, A.A.A. (National Institute of Oceanography and Fisheries, Egypt, 2007)
      The northern lakes of Egypt have always acted as a buffer zone between the drainage system in the Nile Delta and the Mediterranean Sea. Most of these lakes are exposed to high inputs of industrial and domestic wastewater as well as agricultural drainage water, like Lake Manzala, which influence the living organisms on the long run. Samples of zooplankton were collected monthly from ten stations among Lake Manzala showing the different microhabitat of the lake. A one year monitoring has been carried out. Lake Manzala has been changed from marine ecosystem to eutrophic, nearly, freshwater system with the dominance of rotifers (cal ~ 97%). Twenty newly recorded zooplankton taxa were found for the first time in the lake during the study, while thirteen taxa disappeared from the lake in the last fifty years due to these changes. The apparent species turnover rate in the lake increased from 3.26%/year during 60's-80's to 10.29%/year in 00's-03's. Zooplankton abundance was high in northern stations compared with other stations with high densities during March and April. The outlets between the lake and the sea should be more effective to increase the alteration of the lake water with the sea leading to renewal the lake water and decreases the pollution effect on the lake ecosystem.
    • Distribution and relationships of heavy metals in the giant clam (Tridacna maxima) and associated sediments from different sites in the Egyptian Red Sea Coast

      Madkour, H.A. (Alexandria: National Institute of Oceanography and Fisheries, 2005)
      The giant clam (Tridacna maxima) and sediments have been collected from clean and contaminated coastal sites of the Egyptian Red Sea. Selected samples of the giant clam shells and the associated surface sediments were analyzed for Fe, Mn, Zn, Cu, Pb, Ni and Cd. Significant spatial differences in metal concentrations in Tridacna maxima and sediments were identified. Copper and lead are greatly enriched in the giant clam shells, which is related to their physiological function. Cd content is higher in Tridacna maxima than in sediments, because of the easy substitution between Cd and Ca. The levels of most metals in the giant clam shells and sediments were higher in the anthropogenic sites than in the uncontaminated sites. Generally, metal variations reflect natural conditions and human activity. Moreover, there are no clear relationships between concentrations of heavy metals in the giant clam shells and those in sediments.
    • Distribution of chlorinated pesticides in surface water and fish of El Temsah and Bitter Lakes, Suez Canal.

      Said, T.O.; Hamed, M.A. (Alexandria: NIOF, 2005)
      The potential effect of chlorinated pesticides pollutants carried by El Temsah and Bitter Lakes of the Suez Canal was investigated during four seasons of 2003. The results indicate the presence of total DDTs, total cyclodienes and total Hexachlorocyclohexane (HCHs) in surface water with ranges; 2.76-13.88 ng/l, 3.99-16.39 ng/l, and 0.39-1.25 ng/l, respectively. Total DDTs concentrations were ranged from 161-3100 ng/g (wet weight) with an average of 1087 ng/g (wet weight), while total HCHs concentrations were ranged from 30-1145 ng/g (wet weight) with an average of 316 ng/g (wet weight) recorded in three fish species; Lutjanus sp., R. haffara and S. rivulatus of the investigated area. Concentrations of chlorinated pesticides recorded in both of water and fish samples of the investigated area can be ranked in the order; total cyclodienes > total DDTs > total HCHs. Land based activities result from agricultural and municipal wastes are the main source of pollution by chlorinated pesticides in the area.
    • distribution of phosphorus fractions and some of heavy metals in surface sediments of burullus lagoon and adjacent mediterranean sea

      Radwan, A.M.; Khalil, M.K.; El-Moselhy, K.M. (National Institute of Oceanography and Fisheries, Egypt, 2007)
      Twelve samples were collected from the surface sediments of lagoon and adjacent Mediterranean Sea. Samples were analyzed for grain size, total organic carbon (TOC), total carbonate (CaCO3), various forms of phosphorus and heavy metals (Fe, Mn, Zn, Cu, Ni, Co, Cd and Pb). The results indicated that the sediments were composed of sand, silt and clay enriched with carbonate (1.95 – 34.1%) and total organic carbon (0.06 and 3.62%). The total-P content ranged between 58 and 1186 μg/g, and the fraction associated with apatite minerals (PHCl) was the dominant (it constitutes about 50 – 73% of TP) implying that it was the main storage of phosphate. The various P phases demonstrated significant positive correlation with mean size, silt, clay, TOC, CaCO3 and TP, while only Pex was correlated with the metals. As well as, the obtained data indicated that the variations of the measured metals in sediments are varied depending on the locations, whereas the high levels were observed in the western area of the lagoon. The studied gave positively correlated with each other and organic carbon suggested that the distributions of these metals are associated with the organic matter accumulation.
    • Distribution of vanadium in bottom sediments from the marine coastal area of the Egyptian seas

      El-Moselhy, K.M. (National Institute of Oceanography and Fisheries (NIOF), 2006)
      The present study aims to measure the concentration of vanadium in 73 sediment samples collected along the coastal area of the Egyptian seas (Mediterranean and Red Seas). The results indicated that the mean value of vanadium in Red Sea sediments (52.61 µg/g) was higher than the mean value of the Mediterranean (40.58 µg/g) and the variation between the two means was insignificant (p = 0.241). This result could be attributed to the high petroleum activities of the Red Sea. Along the Mediterranean coast, the sector in front of Port Said area exhibited the highest mean value of vanadium (103.9 µg/g) than other sectors, which suffers from many sources of pollution. While the highest mean value along the Red Sea coast (73.20 µg/g) was found at the sector of Red Sea proper. ANOVA analysis showed that the differences in vanadium levels at the Mediterranean sectors were mostly significant at p < 0.05. While for Red Sea sectors, the differences were insignificant except that between Red Sea proper and Aqaba Gulf. Station M10 (at Mediterranean – Port Said sector) and station S2 (at Red Sea – Suez Bay) recorded values of vanadium higher than the typical concentration in sediments (20 – 150 µg/g). These two stations receive huge amount of wastes as industrial and agricultural effluents, sewage discharge, in addition to shipping activities, fishing ports and ship waiting areas; in particular, station S2 (Suez Bay) is characterized by petroleum activities.
    • Ecological and fisheries development of Lake Manzalah (Egypt): hydrography and chemistry of Lake Manzalah

      Shakweer, L. (Alexandria: National Institute of Oceanography and Fisheries, 2005)
      Lake Manzalah; the largest delta Lake in Egypt represents a dynamic system that has been undergoing continuous and pronounced changes since long times. In the last year’s this Lake faced drastic problems that retarded its environmental and fisheries development; the most serious one is the discharge of waste water. It is attempted in the present study to investigate the chemical characters of Lake Manzalah water during 2001-2002. Water temperature ranged from an average of 12.35oC in January and 29.14oC in July. Dissolved Oxygen, pH and total dissolved solids were found in ranges optimum for the living of marine and freshwater fish species. The average concentrations of nutrients lied in the following ranges: 1.24 to 4.89 μmol PO4 -3 l-1 , 5.08 to 28.73 μmol SiO4 -2 l-1 and 1.81 to 17.7 μ_mol NO3-1 l-1 The concentrations of phosphorus and nitrogen compounds were found to be relatively higher at the southern regions of the Lake near to the outlets of the drains.
    • Ecological studies on fish farms of el-fayoum depression (egypt)

      Konsowa, A.H. (National Institute of Oceanography and Fisheries, Egypt, 2007)
      This study was carried out at the fish farms of El-Fayioum province during 2003 farming season. They extend along the eastern bank of Lake Qarun. These farms derive its water and drainage wastes into Diar El-Berka Drain. pH values at the chosen farms ranged between 7.43 and 8.91 and its values are certainly optimum for fish culture. Salinity levels at fish farms adjacent to Lake Qarun (Goda 2, 9.5‰) are generally much higher than the other fishing ponds due to seepage from the lake water. The major nutrient concentrations (N & P) at the main feeder were much higher than the corresponding values at fish farms. Nitrogen concentrations that represented by NO2-N, NO3-N and NH4-N indicated the dominance of NH4-N over NO2-N and NO3-N at the selected fish farms (0.026, 0.091 & 0.59 mg/L respectively). Total organic phosphorus (TOP) concentrations at the chosen farms were much higher than the corresponding values of orthophosphate. The abundance of phytoplankton reached the climax during January and March (8746, 6937 x 104cell/L respectively), but showed a severe drop during September and October (59, 38 x 104cell/L respectively) at all farms under investigation. Oreochromis niloticus prefers diet on Navicula spp. and Cyclotella spp. from diatoms; Prorocentrum apora from dinoflagellates; Euglena spp. and Phacus caudatus from euglenoids and few species of green and blue green algae. So it should decreases supplementary foods at these farms during the abundance of phytoplankton items in spring and summer seasons. Fish production of these farms depends on intensive aquaculture in which the fishes are fed with external food supply. This kind of aquaculture can be changed to extensive production during spring and summer seasons.