Mesopotamian Journal of Marine Science

Three category of tidal water exchange system depended ponds have been selected for the experiments which were canal connected, river connected and pond connected pond. Present study was undertaken to estimate the nutrient balance into the coastal shrimp ponds of Cox’s Bazar coastal region. It was found that mineral fertilizer, organic fertilizer, feed, fish and shrimp fry, water supply and rainfall are the nutrient input and crop product (fish, shrimp, crab), crop residues, denitrification, water discharge and sedimentation are the nutrient output for shrimp pond. Estimation of overall nutrient mass balance per hector basis indicates that fertilizer was the highest nutrient contributor as followed by the supplementary feed into the experimental ponds. The total inputs of nitrogen and phosphorus were 78.87 kgha-1cycle-1 and 42.85 kgha-1cycle-1 respectively. Among the input only 34.6 % of nitrogen and 7.20 % of phosphorus were removed as harvested shrimp, fish and crab. A large portion, 38.58 % of N and 91.38 % of P were remained in the sediments and unaccounted for. From the investigation on nutrient balance for 3 categories of shrimp ponds it was concluded that Reuse water or pond connected pond system for coastal shrimp ponds should not be practiced anywhere in Bangladesh.

This paper reports the first record of three species of aquatic oligochaete worms from Al-Hawiezah marsh, south of Iraq. It was evident that the specimens belonged to the family: Naididae, subfamily: Tubificinae, Species: Aulodrilus pigeuti; Embolocephalus velutinus and Limnodrilus profundicola. A. pigueti is a new record for Iraqi fauna. The study includes the identification and description of these species together with photographic illustrations of chaetal types of each species.

Two widely distributed and economically important food fish in the Red Sea were investigated. A total of 101 specimens of Epinephelus tauvina and 120 Abalistes stellatus were collected from Al-Mehwat local fish market, Hodeidah City, Yemen, between October 2009 and April 2010 and examined for their parasites. Two digenean species of the suborder Hemiurata, namely Derogenes varicus (Müller, 1784) and Dinurus scombri Yamaguti, 1934, were found in these fishes. The former parasite occurred in 15% of A. stellatus and 4% of E. tauvina and its mean intensity of infection was 4.2 and 3.5, respectively while the abundance was 15 and 4, respectively. The latter parasite occurred only in 1% of E. tauvina, with a mean intensity of 2 and an abundance of 0.02. The present study represents the first record of these two parasite species in Yemeni waters of the Red Sea. In addition, E. tauvina now represents a new host for D. scombri.

This study includes laboratory uptake and depuration experiments. The bivalve C. fluminea is exposed to 5ml of WSF of Nahran–Umar crude oil for each liter of river water for 48 hours in the static toxicity test system. The exposure water and animals are periodically taken for analysis of total hydrocarbons concentrations by spectroflurometer. After the exposure period is over, the bivalve transferred to clean river water for depuration period of 48 hours. The experiments show that there are no mortalities due to WSF of Nahran–Umar crude oil. The bivalve is usually active during the 12–16 hours of the experiments. Hydrocarbons concentrations in the exposure water decreased are slowly in a linear fashion so that no measurable concentrations remained after 32 hours. Hydrocarbons accumulated by the bivalve are slowly during the first few hours of exposure. After 2 hours of exposure, the concentration of hydrocarbons is approximately 0.38 ppm in water, while in tissues it is 4.8 ppm. After 20 hours, hydrocarbons are present in water at a concentration of 0.09ppm, while the bivalve tissues contained 17.7 ppm hydrocarbons. After 25 hours of exposure, the hydrocarbons concentration decreased in the bivalve tissues. At the end of the exposure period, the bivalve contains approximately 7.4 ppm. After 48 hours in clean river water, tissues burden decreased to 0.22 ppm of hydrocarbons. The bivalve remained contaminated with small concentrations of hydrocarbons for 20 days. The complete depuration occurred at 26 days.

Fishing is the most important traditional economic activity of the coastal communities in Bangladesh due to the availability of the diverse fishery resources. The Naaf River estuary is one of the large estuaries in Bangladesh coast, which plays a significant role in the socioeconomic condition of local community and considered as a major source of income through small-scale fishing. This paper highlights d the chronic problems and relative actions through sustainable management of small-scale fishermen of Naaf river. Community based participatory approach (PRA/RRA) was used for semi-structured questionnaire interviews of 120 small-scale fishermen from the three fishing communities soliciting information on their activities, financial flows and the main problems confronting their enterprise. Furthermore, 24 focus group discussions were arranged with different stakeholders to collect data on the organization and management of small-scale fishing as well as to get their opinions on the problems, causes and their consequences. The present study revealed that local communities in Teknaf coast are highly dependent on fisheries resources of the Naaf River. Major problems identified within the fishing community were high dependency to fishery resources, annual catch reduction, catch price fluctuation, by catch discard, lack of processing and preservation facilities, credit facilities, and training supports resulting in a disorganized fishing community with poor economic return. To ensure the sustainability, the fisheries sector need to overcome these increasing problems through management plan focusing on optimum fishery resources exploitation taking into account the top down and bottom up views of different stakeholders, “Community Based Fisheries Co-management” framework has formulated for long term sustainability and livelihood security of local community. This will go along way to help sustain the coastal fisheries resources with active participation of the fishermen.

A new method of complex formation between cobalt or copper ions and Schiff Base (derived from Schiff Base of salicyldehyde and amino acids) was adopted for the determination of cobalt and copper ions in water samples of Shatt Al-Arab River. For water sampling three stations along Shatt Al-Arab River were selected as follows: 1) discharging point in Shatt Al-Arab from Basrah paper and mill industries, 2) Karmatt Ali Bridge, and 3) Siba downstream to the southern region of Shatt Al-Arab river. After the formation of a complex with Schiff Base, Cobalt and Copper in the water of Shatt Al-Arab were determined spectrophotometricaly at wave length of 270 nm and 295 nm respectively. It is found that cobalt concentrations were (0.152, 0.174, 0.165) mg.l-1 and copper concentrations were (0.014, 0.021, 0.023) mg.l-1 in stations 1, 2 and 3, respectively. The method is reliable with sensitivity, accuracy, standard deviation and detection limit of (0.0235 gm.cm.l-1, 3.05×10-6, 0.00184, 0.52×10-7) for cobalt complex and (0.0135 gm.cm.l-1, 3.31×10-6, 0.00215, 0.6×10-8) for copper complex, respectively.

The seasonal variations of n-alkanes compounds in molluscs of Shatt Al-Arab river have been studied. The species of molluscs were the snails, Lymnaea auricularia, Theodoxus jordani, Physa acuta, Melanopsis nodosa, Melanoides tuberculata while the bivalves were Corbicula fluminea and Corbicula fluminalis. The molluscs were collected from different locations of Shatt Al-Arab river (along the region extended from Abu-Al-Khasib to Garmat-Ali) during 2004 and 2005. Each species consisted of at least 350 adults of uniform size of individuals. The n-alkanes compounds from species of molluscs were extracted and analyzed by high resolution capillary gas chromatography. The total concentrations of n–alkanes in the molluscs varied from 1.50 μg/g dry weight in the T. jordani to 8.78 μg/g dry weight in the C. fluminea during summer and from 2.26 μg/g dry weight to 12.37 μg/g dry weight during autumn. While ranged from 3.15 μg/g dry weight to 12.44 μg/g dry weight and from 1.78 μg/g dry weight to 5.31 μg/g dry weight during winter and spring. The study confirmed lower concentrations of n-alkanes compounds in the molluscs of Shatt Al-Arab river during summer and spring while higher concentrations were recorded during winter and autumn. This is due to several factors which could act to produce such seasonal variations.