Objectives: The fish samples were collected from the three different cities of Yemeni coasts. Aden, Al-Hodeidah and AL-Mukalla were chosen for the sample collection. Lethrinusmahsena, Thunnustonggol, Sphyraenajello and Epinephelusareolatus fish samples were considered for the study as they are more common eatable fish among the population. Methods: The study was carried out in the all three seasons of winter 2011, summer 2012 and winter 2013 in order to check seasonal variation of heavy metal pollution.Total Fish (108 samples of each muscles, liver and gills) were analyzed. The four heavy metals lead, Cadmium, Mercury and arsenic which are considered highly toxic were detected in the samples in the year 2010, 2012 and 2013. Results: The mean concentration of Pb, Cd, Hg and as in muscle was 0.101±0.012, 0.046±0.010, 0.058±0.002 and 0.089±0.002µg.g-1 dry wt. respectively; whereas in liver was 0.196±0.033, 0.132±0.020, 0.102±0.007 and 0.115±0.0005µg.g-1 dry wt. respectively; whereas in gill was 0.294±0.042, 0.196±0.063, 0.016±0.0006 and 0.034±0.0005µg.g-1 dry wt. respectively. The results showed that, the heavy metals concentrations were high in stations AL-Hudaydah and AL-Mukalla and low in station of Aden. Also the heavy metals concentrations were high in Seasons summer and low in Seasons winter. Conclusion: From the heavy metal concentrations mentioned above we can see that somewhere the concentration is crossing the limits as permissible by the World Health Organization. It suggests a high risk to the health of human being on the consumption of contaminated fish. Therefore it is recommended that the practice of trace element detection should be continued in order to update whether the heavy metal concentration is above or below the permissible limits and if it is above the limit then precautions must be taken to avoid possible consumption of contaminated eatables.

Objectives: The present work has been done considering the constant spread pollution of heavy metals in water bodies. Pollution among water bodies is a major global problem. This contaminates not only the water but also the sediment and aquatic life such as fish. The water samples were collected from the three different Cities of Yemeni coasts. Aden, Al-Hodeidah and AL-Mukalla were chosen for the sample collection. Methods: The study was carried out in the all three seasons of winter 2011, summer 2012 and winter 2013 in order to check seasonal variation of heavy metal pollution.Total 81 samples of each Water were analyzed. The four heavy metals lead, Cadmium, Mercury and arsenic which are considered highly toxic were detected in the samples in the year 2010, 2012 and 2013. The heavy metal concentrations in the samples were measured using the Atomic Absorption Spectrophotometer. Results: The obtained results showed that the concentration (mg/l) of the heavy metal in seawater (Pb-0.061±0.005, Cd-0.007±0.001, Hg-0.007±0.0005 and As-0.008±0.0003) mg/l. The obtained results showed that the heavy metals concentrations were significantly higher, during the summer season for seawater samples in all stations during the study period. Because of the frequent use of water in the hot summer, results in an increase in sewage, as well as to the high rate of environmental variables in the summer. Conclusion: By comparing the results obtained with other data obtained from the local and international studies, in addition to, comparing the results standard levels of these metals contaminated and adopted internationally and domestically and the pollution levels in Yemen is currently within the lower limits of pollution. However, the study recommends continuing the study of these pollutants and other contaminants and their impact on the environment and marine life especially invertebrates.

New Co(II), Ni(II) and Cu(II) complexes with urea and asparagine as ligands have been synthesized in (M:L1:L2) molar ratio (where M= Co(II), Ni(II) and Cu(II), L1 =urea, and  L2 =asparagine) then identified by micro analytical data, molar conductance measurements,  IR, 1HNMR, Mass, UV-VIS spectroscopies and magnetic susceptibility measurements. Thermal degradation studies were carried out by thermal analysis. These complexes have the general formula [M(L1)(L2)(H2O)n]Cl. The molar conductance values in DMSO solvent show the electrolytic nature of these complexes, indicating the outer-sphere coordination of the chloride anions with metal ions. The three complexes have an octahedral structure although urea has shown two modes of coordination. Thermal analysis study shows rapid decomposition reaction for Ni complex and the highest thermal stability for Cu complex. The kinetic parameters were determined from the thermal decomposition data using the Coats-Redfern method. Thermodynamic parameters were calculated using standard relations.

The reaction of urea (ur) and glycine (gly) with the metal ions Co(ΙΙ), Ni(ΙΙ) and Cu(ΙΙ) in ethanolic solution of 1M:1L1:1L2 molar ratio (where M= Co(II), Ni(II) and Cu(II), and L1 = urea L2 = glycine) led to the preparation of complexes of the general formula [M(ur)(gly)(H2O)2]Cl. Elemental microanalysis (CHN), molar conductivity measurements, IR,1HNMR, Mass and UV-VIS spectroscopic, and magnetic susceptibility measurements were used for the characterization of the compounds. Thermal analyses were used for the complexes degradation characterization. The complexes have an octahedral geometry and are of electrolytic nature in DMSO solvent with the absence of inner-sphere coordination of the chloride anion. An inhibition zone was observed for Ni-urea-glycine complex against Escherichia coli when the biological activity was considered.

The reaction of urea (ur) and glycine (gly) with the metal ions Co(ΙΙ), Ni(ΙΙ) and Cu(ΙΙ) in ethanolic solution of 1M:1L1:1L2 molar ratio (where M= Co(II), Ni(II) and Cu(II), and L1 = urea L2 = glycine) led to the preparation of complexes of the general formula [M(ur)(gly)(H2O)2]Cl. Elemental microanalysis (CHN), molar conductivity measurements, IR,1HNMR, Mass and UV-VIS spectroscopic, and magnetic susceptibility measurements were used for the characterization of the compounds. Thermal analyses were used for the complexes degradation characterization. The complexes have an octahedral geometry and are of electrolytic nature in DMSO solvent with the absence of inner-sphere coordination of the chloride anion. An inhibition zone was observed for Ni-urea-glycine complex against Escherichia coli when the biological activity was considered.