A study was undertaken in the aquatic environment, including the Shatt al-Arab River, the Shatt al-Basrah Canal, and the Arabian Gulf. The study extended over a period of six months from May - October 2000. Bacteriological analysis was done to determine the total plate count, total and fecal coliform and its relationship with Salmonella. In the present study, we observed that it is possible to detect and isolate Salmonella under very low coliform densities. Thus the usefulness of the fecal coliform concentration for making a qualified judgment of water quality must be reconfirmed.

During two occasions, April 1982 and October 1995, samples of surface sediments were collected along the Shatt al-Arab River. Samples have been extracted for lipids in which concentration of petroleum hydrocarbons (PHCs) were determined spectrofluorometrically. Total PHCs reported for the two periods, expressed in terms of Basrah crude oil equivalents, were 2.6 - 20.5 and 2.63 - 15.39 µg/g respectively. Nickel and vanadium have been analyzed by using an atomic absorption spectrophotometer. Average concentrations of Ni and V as dry weight in the sediments were in the range of 76.3 - 98.4 and 39.6 - 63.6 µg/g for 1982 and 53.52 - 81.6 and 32.6 - 62.04 µg/g for 1995 respectively. Sedimentological features, grain size, and % TOC were estimated for sediment samples. There is a good correlation between these sedimentological features, Ni and V, as well as PHCs. The distribution of oil residues and associated trace metals in these sediments is discussed as a feunction of sedimentological features and these features have an apparent effect upon the distribution of oil. The average values reported for PHCs as well as the related trace metals Ni and V were lower in concentrations during 1995 compared with 1982, indicating unpolluted events of 1991 events upon the environment of the Shatt al-Arab River.

The larvae of two species of Mugilidae were identified from the ichthyoplankton samples in the Khor al-Zubair and Shatt al-Arab estuaries. The spawning area is supposed to be in the offshore area near the mouth of each estuary during the period from December to February for Liza carinata and from March to June for Liza subviridis. Migration interrelation with the growth of the larvae from offshore to near shore was proposed for both species.

Stomach contents of 375 specimens of Sardinella albella collected from the Iraqi marine waters of the northwest Arabian Gulf were analyzed from March to November 1999. Phytoplankton is the principal food item (64.3%) of the food components, which consist of diatoms (48.6%) represented by the genera Biddulphia, Coscinodiscus, Fragilaria, and Niltchia, and blue-green algae (15.7%) represented by the genus Oscillatoria. Zooplankton forms (35.7%) were the second most important food item, and included copepod zooplankton (20.7%) and non-copepod zooplankton (15.0%). High rates of feeding intensity and activity were observed from March to May.

Between January 1994 and June 1995, a total of 240 fish samples belonging to 13 species of freshwater fishes were collected. They were Acanthobrama centisquama, Alburnus caeruleus, Barbus luteus, B. grypus, B. sharpeyi, B. xanthopterus, Cyprinus carpio, Cyprinion macrostomus, Chalcaburnus mosulensis, Garra rufa, Heteropneustes fossilis, Mystus pelusius, and Liza abu. The fishes were collected at monthly intervals from the al-Qadisiyah Dam Lake using gill nets as well as beach seine nets of different mesh sizes. Microscopic examination revealed that the fishes were infected with four species of flagellates, two ciliates, eleven sporozoans, twelve species of monogenetic trematodes and one species of digenetic trematode, one species of cestode, and two species each of nematodes and canthocephalians. Moreover, four species of crustaceans and one fungal species were observed.

The recording of Cryptobia sp. in A. centisquama and L. abu, as well as Dioctophyma sp. in A. caeruleus represent the first record of these two species in Iraq. The present study describes 27 new hosts for 17 species of parasites.

The level of total petroleum hydrocarbon concentration was measured in dissolved and suspended matter in water from Shatt al-Arab, Khor al-Zubair, and other regional waters of Iraq. The highest level of dissolved matter for petroleum hydrocarbons was 80 µg/l in al-Amique port during May 2001, while the lowest level (0.91 µg/l) was found in the al-Zubair bridge region during 9-10 July 2001. The highest level of suspended matter for petroleum hydrocarbons was 33.4 µg/g in Khor Abdullah during May 2001, and the lowest level (0.8 µg/g) was found in the al-Zubair bridge and Khor al-Zubair port regions during 9-10 July 2001. The results showed variations in the concentration and its increase at some stations. This confirms the probability of a petroleum leak. An irregular leakage in southern Iraqi rivers may be due to industrial processes or waste from loading band transportation of ships.

The biomass and secondary production of the barnacle B. a. amphitrite were estimated from monthly quantitative samples collected from al-Toza, Garmat Ali for the period November 1994 - March 1996. The shell formed about 62% of body mass, whereas the dry weight and moisture constituted about 4% and 35% respectively. The annual amount of energy was 4.250 kcal/g DW, and 5.385 kcal/g AFDW. There were seasonal differences in the values of calories in terms of DW and AFDW. The biomass was 56.806 g DW/m² and the production amounted to 149.088 g DW/m²/yr (617.582 kcal/m²/yr), whereas the biomass in terms of AFDW was 44.63 g/m² and the production was 119.421 g/m²/yr (603.827 kcal/m²/yr). The P/B ratio was 2.7 for both the DW and AFDW. This vindicates the success of the species in invading the Shatt al-Arab region and its surroundings.

Marine and freshwater shrimps of Metapenaeus affinis were stored in ice after having been collected for different periods. The results showed a clear change in the sensitive properties of the two kinds. The percentage of moisture was higher in marine shrimp, while being inconstant in freshwater shrimp during icing storage. Protein, fat, and ash decreased during the storage of both kinds of shrimp.

Higher pH occurred in the marine shrimp, while the pH values of the freshwater shrimp were unstable. The peroxide number and total volatile nitrogen increased in both marine and freshwater shrimp.

The nature of the small fish assemblage in the Shatt al-Arab Estuary was studied during the period from August 1999 to July 2000. Fifty-three species were obtained, represented by 4419 individuals. The number of species increased during the period from May to August. Four families formed 58.25% of the total catch, namely Engraulidae, Sciaenidae, Platycephalidae, and Clupeidae. Nine species (Thryssa mystax, Platycephalus indicus, T. hamiltoni, Leiognathus bindus, Johneiopes sina, Arius bilineatus, Cynoglossus arel, Ilisha elongata, and Grammoplites scaber) constituted 59.09% of the total numbers. Positive correlations were obtained between both number of species and the total number of individuals with water temperature, transparency, and salinity.