Ichthyofauna and some biological indices in Karoon, Dez and Bahmanshir Rivers (southwest of Iran)

During one year survey (1992-1993) 47 different species of fishes were caught by drift gill net from Bahmanshir, Karoon and Dez rivers. Distribution, frequency, ecological indices (diversity, richness and dominance), salinity coefficient (for Karoon and Bahmanshir rivers) were also calculated. In Karoon Rivers 32 species, in Bahmanshir 25 species and in Dez 12 species were identified. Freshwater fishes of Karoon include 17.9%, Bahmanshir 5.9% and Dez 14.6% of total freshwater fishes in Iran. Among identified fishes 4 nor endemic species, 2 anodermus species and the rest are dwelled and one species is rare. The most frequent species were: Clupeidae (3 genus and 3 species) in Bahmanshir river, and Cyprinidae (10 genus 16 species) in Dez river and (12 genus and 19 species) in Karoon river. Also the maximum fish abundance was in autumn, in Bahmanshir and Dez rivers and in spring in Karoon River. The similarity percentage of species between Karoon and Bahmanshir was very low. The maximum diversity and evens also belong to Bahmanshir and the maximum species richness and dominance belong to Karoon River

Abundance, spawning season and type of gattan (Barbus xanthopterus Heckel, 1843) in south of Karkheh River and Hour-Al-Azim marsh (Khuzestan Province)

In this study 401 specimens of Gattan (Barbus xanthopterus) caught by drifting and set gillnets, cast nets and forks were studied. Samples were collected monthly (October 1996 to September 1997) from Hamidieh Dam to Hour-Al-Azim Lagoon. Morphometric and meristic parameters and biological characteristics were studied in the laboratory. The Highest frequency of Gattan in the river was in March and in Hour-Al-Azim was in December. The length range of the fish in the river was broader than in the hour, and fishes with lengths more than 700mm were only observed in the river. Sharp decrease in GSI in May and occurence of spawning in May and June showed that reproduction of this species occurs in spring (in a two month period) and is relatively short. Minimum and maximum ova diameter were 0.01mm and 2.25mmin stages II and IV of gonad maturity respectively. An increasing trend in ova diameter up to April and decreasing in June showed one time spawning of this species. Surface water temperature in the spawning season was between 25.5oC and 28.65oC and turbidity was in its lowest level in this period. Sex maturation in males occurred in length of 151-200mm (one year old), and in females in 501-550mm (3 years old). Average sex ratio (male to female) was 1:1.31 which is not significantly different from 1:1 (95% confidence limit)

Determination of biomass of fishes in Shadegan Wetland

Biomass estimation of fishes were done by depletion method in Shadegan Wetland in 2011-12. Fishing effort and landing catch amount per unit effort was done via random oversea in fixed landing area monthly. Fishermen and catch statistics were obtained from census. Total catch was calculated from multiplication of effort and average catch. Fishes biological characteristics survey indicated that Golden barb (Barbus luteus) and Berzem (Barbus pectoralis) has maximum (62 kg/ha) and minimum (4 kg/ha) biomass respectively. Maximum and Minimum biomass was in spring (380 kg/ha) and in winter (58 kg/ha) respectively and mean biomass was estimated 249 kg/ha in whole area during one year. Number of fishermen were about 1317 and maximum fishing effort was in April, May and June. Total fish landing was 4300 tons per year in which 1119 tons was calculated in April. Large scaled barb (Barbus grypus) and Abu mullet (liza abu) had maximum and minimum mean length and weight. The range length of most of fishes was low and their spawning season was in winter and spring. Length- weight relationship indicates their isometric growth. Despite of 45% decrease of number of fisherman to previous time (2008), catch effort and exploitation was increased (20%). Regarding fish living area (70000 ha), total biomass was 17430 tons

Species composition monitoring in artificial reefs area in Khuzestan coastal waters

This study was carried out in continuation of previous studies on artificial reefs monitoring in Khozestan coastal waters. The main purpose was the zoo species composition on and around the artificial reefs. Sampling was done from May 2012 to April 2013, from 4 stations in artificial reefs area. Reef structures were sampled by scuba diving. Physical and chemical parameters were measured and water quality status was determined by using WQS index. Zooplankton and macrozooplankton communities were sampled by 100 and 300 micrometer mesh size nets respectively. Benthic animal's samples from sediments around of the reefs body were collected by Ekman grab. Sediment characters, TOM and grain size were analyzed by using ignition loss and size series sieves methods respectively. Secondary production of macrobenthic animals based on dominant species length classes was estimated. Ichthyological information recorded by diver (census and video recording) and Gargoor traps were used for fishing effort calculation .Except for nitrite parameter (p<0.05) in different stations and silica parameters (p<0.05) in different months, other parameters were not shown significant differences in studied stations and months. The mean of zooplankton density was (914±52) N/m^3 and the Copepoda species were the most abundant group (235 ±10) N/m^3.Anosim analysis showed no significant differences in reefs specie composition. Different Crustacean groups were included more than 82 percent of macrozooplanktons communities. Among macrozooplankons, the mean density of decapoda, branchiopoda and copepoda were 302, 296 and 191.5 N/m3 respectively. The mean density of macrobenthic animals was 418±90.26 N/m^2 and mollusk, crustacean and polychaets were the most abundant benthic animals respectively. During the study period, total macrobenthos biomass 11.37 g-wet/m^2 and its mean value 2.84 g -wet /m^2, were estimated. Annual production for polychaets and crustacean groups 154g-wet/m^2 and 182 g-wet/m^2 were estimated respectively. Annual production of total macrobenthic animals was about 675 g-wet/m^2/y. According to sediment analysis, the range of silt-clay (8.7-95.6)% and seasonal mean TOM (4.47-13.25)% were calculated in studied stations. According to attached organisms biomass (wet weight), Cnidarian Anthozoa class with (88)% was the most abundant and then sponge (10)%, Cnidarian Hydrozoan class and arthropoda each one with 1% were included total attached organisms. Due to high biomass of Anthozoa species the most abundant mean was observed in spring season. The Malacostraca group especially Crustacean (72)% was the main mobile animals on reef bodies and then Echinodermata (Ophiurida and marine Orchids) (18)%, Mollusca (Bivalves and Gastropods) (4)% and Polychaets (3)% were the main mobile organisms. The range of Shannon diversity index was (3.22-3.46) and (2.44-3.38) in studied stations and months respectively. Totaly in studied area, the number 15 fishes species were observed and Sparidae family with 3 species were the diverse fish family. The fish Hamour (Epinephelus coiodes,Seranidae) (87)% was presented in all studied months and stations. After Hamour the Neopomacentrue sindensis and Diplodus sargus Kotschyi were the most abundant fishes. The maximum and the minimum of hamour catch per unit effort were in reef B in spring and reef C in autumn respectively .Data comparing showed that except for nitrite the other physical and chemical parameters were observed in the same range by 2005-2007 study. According to obtained results, Zoo communities in different part of ecosystem showed greater diversity than to past years and in comparing to mudflat coastal waters in Khozestan waters, new ecosystem has been created in the region. High diversity of different animal groups that were disperses in water column in early phases of its life and need to settlement to substrate to continuing the life were observed in area. Attached animals plays an important role in biological and ecological characters in the coastal area

Artificial reefs monitoring in Khuzestan coastal waters

This research was done to study on communities' strucure of benthic animals' growth on artifitial reefs, constructed in Hendijan coastal waters in khozestan in Nort west Persian Gulf. The seasonal sampels of attached organisms were collected from spring to winter during 2010 year study.One station (D) in older and three stations (A, B, C) in newer reef site were selected.Random sampling was carriedout by using quadrat (25×25) via diving. During survey, the number of 59 species of attached animals belong to 13 animal groups, including, 9 species of cnidarian, 8 species of spoges, 7 species of Gastropoda, 8 species of Bivalve, 4 species of polychaet and 17 species of Crastacean were identified. In studied artifitial reef apoint of biomass, softcoral were dominant group which include 92% of total biota, and the species Plumarella sp. is the dominant species. However, apoint of abundance the species pisidia sp. from anomura crabs was the most abundant species especially in station A and D. Different kind of Cnidarian such as Dendronephthya sp., Sarcophyton sp. And Lobophyllia sp. was observed in station D for the first time. The polychates, Mollusk and some of crustacean and Echinodermata species were observed in lower abundance in comparision with previous studies. This results show that communities have been changed along time. According to MDS analysis, based on Bray-Curtis similarity, different stations presented seasonal variation based on identified species-biomass. Clustering analysis based on mean biomass indiffernt seasons explained that. Station D in 55%, station B in 75% and staton A and C in 80% similarity were Seperated. According to obtained results, there were not signifidant differences between station that can be caused by similarity in structural characteristics such as bottom slope and age of reefs. The mean abundance in spring was significantly high than other seasons. Which can be caused due to bioticfactos such as life cycle and reproduction season? In this research, fish communities accord to recorded information by visual consus and fisheries Traps arund the reefs, hare been increasing. In present study with increasing biomass in the biotic communities on artificial reefs enhancement of fish stock most be expected. These substrates can be reduced the pressure on destructed which is the opportunity for rehabilitation. In present study with increasing biomass in the biotic communities on artificial reefs enhancement of fish stock most be expected. These substrates can be reduced the pressure on destructed which is the opportunity for rehabilitation. The most frequent and abundant fish species was Epinephelus sp. This species was presented in all stations and seasons. The other abundant fish species were Scolopsis sp.,Epinephelus coioides, Diplodus sargus and Neopomacentrue sp.

Identification and density determination of juvenile fishes in Khouzestan coastal waters

Aquatic animals possess specific biological characteristics and lifecycle. Without knowing about their biology and complete lifecycle, planning about their conservation cannot be effective. Following the previous studies on fish larvae in Khuzestan coastal waters this study was done to determination catch composition and density of juvenile fishes in Khuzestan coastal waters during 2007 to 2008. Studied area included two main fisheries ground, Lifeh-Busafe in west and Bahrekan in east coasts. Monthly random sampling was carried out by using shrimp trawl net with Akhtar vessel. Juvenile fish's means the fishes that completed their larval cycle and are look like their parents but have not been matured yet. The catch mean, biomass, CPUA and the stock size of different species were estimated by using Swept Area Method. Totally 101485 caught fishes included 38 families and 63 species. The most abundant trawled fishes were Thryssa vitriostris Leiognathus bindus Ilisha melastoma Penahia macrophthalmus and Johnius belangerii .These five species contain about 80 %, the species Arius dussumieri and Cynoglossus arel 4.5% and 3.2 % respectively and the others 12% of total caught fishes. In the east coasts the species L. bindus I. melastoma T. vitriostris P. macrophthalmus and in the west coasts the species P. macrophthalmus T. vitriostris J. belangerii and I.melastoma were the most abundant. Among 63 identified fish species , juvenile fishes of 23 species were observed which contain 26.4 % of total caught fishes .the fishes Arius dussumieri and Acantopagrus latus 100%, Liza subviridis, Leiognathus lineolatus and Triacantuhus biaculeatus more than 80 % and Pomadasys stridens Lagocephalus inermis Saurida tumbil and Thryssa vitrirostris more than 50 % were observed as juvenile stage. The most abundant juvenile fishes were T. vitrirostris L. bindus and Arius dussumieri respectively. The maximum (1852 kg/km^2) and the minimum (165 kg/km^2) values of CPUA were estimated in west coasts in July and December respectively. The maximum (2677 kg/km^2) and the minimum (153 kg/km^2) values of CPUA were estimated in east coasts in June and August respectively. The biomass showed a distinct peak in June and July in east and west coasts respectively. The highest diversity index in east (2/22) and west (2.36) coasts were obtained in July. In present study the number of identified fishes is more than previous studies. Juvenile fishes spend their sensitive period of lifecycle in Khuzestan coastal waters. After growing in late spring, fish larvae enter to the juvenile stage and select this productive area as nursery ground. Increasing of juvenile fishes in July is accordance with their reproduction season in studied area. The east coasts are deeper than the west and there are some differences in hydrological characteristics due to discharging of the rivers Bahmanshir and Arvandrood in west coasts. The peaks of abundance in east and west coasts were observed with a clear time interval. The higher CPUA in east coasts can be caused due to gradual migration of juvenile fishes from west to east during cold season

Study on Mahshahr creeks (north of Persian Gulf) as protected area

In recent years MPAs (Marine Protected Areas) have been known as a flexible tool to improve fishery management as well as to preserve biodiversity in valuable coastal waters habitats. This study was conducted to selecting the sensitive and high potential area that are impacted by several environmental stress and associated habitats are being damaged in Mahshahr creeks in Northwest of Persian Gulf. Study was done in eight creeks from October 2005 to September 2006. Different biotic parameters such as phytoplanktons, zooplankton, macro zooplankton, benthic animals and fishes (trawled species) communities and also physico-chemical parameters and sediments heavy metals were investigated. Different parameters were sampled monthly or seasonal from each creek. Water samples with bottle sampler and sediment were collected by Peterson grab. Several ecological and biological indices based on heavy metals and benthic communities were used. Concentrations of heavy metals were measured by using voltammetric plarography method (Methrom 797). The range and mean concentrations obtained in mg/kg were 35.16-15.03 (27.01) for Cu, 171.41-65.57 (102.672) for Ni, 20.06-4.63 (13.22) for Co, 0.78-0.093 (0.22) for Hg, 379-65.07 (113.7) for Zn, 1.00-0.27 (0.559) for Cd and 29.72-7.09 (14.66) for Pb. To evaluate the levels of sediment contaminations, the background values of the different heavy metals were calculated and contamination factor for each metals and degree of contamination for each creek determined as well. Measured concentrations were compared with International standards. Ultimately the heavy metals contamination factors (Cf) can be arranged as follows: Hg> Zn> Cu≥ Ni> Pb≥ Co > Cd and according to contamination degree (Cd), different creeks can be arranged as follows too: Ghannam> Ahmady≥ Zangy> Doragh≥ Darvish> ghazaleh> Patil> Bihad Regarding the results some elements such as Hg, Zn and Ni, are at risk level and all of the studied creeks are classified in moderate degree of pollution except Ghannam showing considerable degree of pollution. The benthic invertebrates are a well-established target in evaluations of environmental quality status. The AMBI (AZTI,s Marine Biotic Index) was developed to determine the impacts and the quality status in softbottom marine benthic communities. All creeks are characterized by muddy bottom. Macrobenthic animals, according to their sensitivity to an increasing stress gradient, classified in five ecological groups. In present study due to appearance of dominant species such as Capitella sp and nematodes (as opportunist species), diversity values was reduced. Two way ANOVAs showed only seasonal significant differences in mean abundance (P<0.05, f=5.712, df: 3,21) and Richness index values (p<0.05, f= 4.975, df=3,21), while all of creeks showed similar biological characters based on benthic communities. According to annual, mean of AMBI (BC) all of creeks classified in ecological group III with slightly pollution, except Darvish that was placed in unpolluted category. In general, according to AMBI and BI values, The most creeks are classified in unpolluted (34%) and slightly pollution (34%) categories except Zangy, Doragh and Patil in summer and also Zangy and Bihad in winter that showed moderate to heavily pollution (32%). The results of chemical quality of sediments, Cf values, Cd values, AMBI Index and water quality and risk Indices have confirmed each other. In general, the Mahshahr creeks are classified in moderate to heavy pollution status. In addition, biological parameters of benthic communities and other biotic parameters have showndescending trend in ecological quality in all of the studied creeks. Communities. According to annual, mean of AMBI (BC) all of creeks classified in ecological group III with slightly pollution, except Darvish that was placed in unpolluted category. In general, according to AMBI and BI values, the most creeks are classified in unpolluted (34%) and slightly pollution (34%) categories except Zangy, Doragh and Patil in summer and also Zangy and Bihad in winter that showed moderate to heavily pollution (32%). The results of chemical quality of sediments, Cf values, Cd values, AMBI Index and water quality and risk Indices have confirmed each other. In general, the Mahshahr creeks are classified in moderate to heavy pollution status. In addition, biological parameters of benthic communities and other biotic parameters have showndescending trend in ecological quality in all of the studied creeks. We used of some criteria for evaluation of biotic potential or sensitivity and also to explain the ecological health level of studied creeks. Positive and negative criteria are classified in three level 1, 3 and 5 for low, moderate and high degree of conservation value respectively. According to gained points the creeks Darvish, Doragh and Ghazaleh in high level and creeks Ghannam , Zangy and ahmady in low level of conservation value were classified

Biology of southern meager (Argyrosomus hololepidotus) in Khouzestan province coastal waters

In order to study feeding and reproductive biology of Southern meager (A.hololepidotus) in North West of Persian Gulf. 143 (74 males and 69 females) species were collected between October of 2008 to October of 2009 in coast of Khouzestan. Maximum and minimum length of fish were 143 cm and 81 cm respectively Maximum mean length (128.4±7.5) and Minimum mean length (104.86±12.47) were detected in October and May respectively. Maximum weight (27.5Kg) and Minimum weight (5.7Kg) and also mean weight to males (15222±1371) and Min mean weight of females (16942/02±2095) were detected. Absolute fecundity (4111847.66) and relative fecundity (268.33) were analyzed. GSI Analysis showed that these species (A.hololepidotus) spawn during June to September with highest spawning rate in September. Results showed that Southern meager is a batch spawner species relationship between length and weight of male Y=0.042L^2.70 (n=74,R2 =0.86) and female species Y=0.061L^2.61(n=69, R2=0.85) and also total species Y=0.059L^2.62 (n=143, R2=0.86) were measured. Due to not finding Immature species during sampling LM50 wasn’t analyzed. Analysis HSI and K index showed highest value in April and May and lowest value in August and September respectively. Prey occurrence index showed that fish is main food item and Crustacean specially Shrimp and Mollusca are secondary food item of this species. Analysis of vacuity index showed that females of Southern meager are more gluttonous than males and this species feed during spawning season. In general we can classify Southern meager as a moderate feeding rate species

Survey on ecological characteristicsof Horolazim wetland in Khouzestan (2012-2013)

Rregarding the potential and capabilities of different socio-economic, ecological and recreational, Hurolazim wetland is allocated as a special place in the collection of ecosystems and environment and the study of existing ecological conditions is necessary to protect and restoring management. In this study, monthly Samples of four stations (stations north of the road, Imam Reza (1) and south of the road, Imam Reza (2), in the Rofayeh area and stations Tabor (3) and the Shatt Ali (4), in the Shatt Ali area) were taken during the year from April to March 2012. Samples included physical and chemical parameters, phyto and zoo planktons, benthos, fish, and fishing status. Phytoplankton samples using sampling bottles from 0.5 meters below the surface were taken and counted based on alive unit. Zooplankton samples were collected by 100 micron mesh size plankton net from a depth of 1.5-2 meters. Benthic animals and sediment were sampled by Van Vin grab(0.125 square meters). One sample for benthos and one sample for grain size analysis and percentage of organic matter were sampled from each stations. In order to estimate the monthly depleted catches, data collected from the census in place and sampling was done at the time. Three fishing area has inspected randomly once every 15 days and active fishermen and caches were recorded in the prepared forms during the day. In this way, the number of observed boats, the average boat per day, the catches of the boats and CPUE were registered and total fishing effort was calculated monthly. In this study, 194 species of phytoplankton were identified. Diatoms with 85 species, Cyanophyta with 59 species, Chlorophyta with 31 species, Euglenophyta and Dinophyta with 18 and one species were observed respectively. The highest abundance frequency of phytoplanktons with 38.96 percent were observed in Tabar station (3), Diatoms with 46% has shown the highest frequency and then Cyanophyta (34.17%), Chlorophyta (16.39%), Euglenophyta (1.6 %) and Dinophta (1.58%) were included of the total abundance respectively. In the summer colonies of Cyanophyta were in high density. A total of 35 species of zooplankton have been identified. from Rizopoda, the species of Arcellidae and Centripyxidae families, from Rotifera, the species of Brachionidae, Lecanidae, Asplanchnidae and Philodinidae families, from Cladocera ,the species of Daphnidae, Sisidae and Chydoridae families and from copepods, Cyclopoda families have been observed that included about 98 percent of identified zooplankton. Respectively, Copepoda (39.9 %), Rotifera (34.71 %), Cladocera (22.38 %) and Rizopoda (0.843 %) were dominant groups. The species Brachionus urceolaris with average density of 7.29 individual per liter, is the most abundant species that included 17 % of total abundance frequency in the wetland. The higher frequency of crustacean zooplankton such as Copepoda and Cladocera could be indicated an environment more favorable conditions and expected to be good status of food in the Horolazim wetland. Among the known benthic groups, families, Tephritidae (85%) and Chironomidae (7 %) of the order Diptera and Ostracoda (2 %) from crustacean, were the dominant macrobentic groups Among the studied stations, Station South Road Imam Reza (2), and the station Shatt Ali (4), were the highest and the lowest abundance respectively. The mean abundance of macrobenthos in different seasons showed the lowest and the highest abundance frequency in summer and winter respectively. According to diversity indices, The stations Tabar (3) was the highest and the Station South Road Imam Reza (2), was the lowest value of diversity index. The results showed the higher than 71.84 % of Silt-Clay percentage in all stations, The highest value of sediments TOM in the Station South of the Road Imam Reza(2) in the winter and the lowest in station Shat Ali(4) in summer were recorded. Based on HFBI index the stations north of the road Imam Reza (1) and the station Shatt Ali (4) in moderate status and the stations south of the road Imam Reza (2) and Tabar (3) in good status were classified. In this study, 15 species of fishes belonging to 8 genera and 3 families were identified. It was noticed that 87.4 percent of all identified species in the wetland belonged to the Cyprinidae family. The results of previous studies in 2006 and 2008 in the Iraqi part of Hawizeh wetland showed that the most common fish species belonged to Biah, Karas, Hemry and Shelej that included 89.3 percent of total fishing in the current study .Finally, It is evaluated that changes in water regime of freshwater wetlands, controlled the environmental characteristics and conditions. That means water plays a decisive role in the vital characteristics of wetlands. Changes of quantity and quality of water may be associated with changing the quantity and quality of biotic fauna in wetland system. In the management and protection of a wetland system, it is necessary to adopt measures based on scientific principles and reasonable methods in order to protect water quality