Aims: Mangroves are subjected to a range of abiotic stresses, which affect their growth and normal physiological processes. One of the most important modes of enzymatic antioxidant defense against stress caused by reactive oxygen species (ROS) is superoxide dismutase (SOD). The aim of this study was to evaluate the antioxidant enzymes activity of superoxide dismutase in the avicennia marina from the Persian Gulf and Gulf of Oman in the presence of the metal ions.
Materials and Methods: In the present experimental study, which was conducted on the leaf of avicennia marina, the sampling was carried out from two habitats including Khamir port in the Persian Gulf and Sirik in the Gulf of Oman and the treatments were carried out in 3 replications. H₂O₂ sensitivity test and KCN test were used to determine the SOD type. The data were analyzed, using SPSS 19 software by multivariate analysis of variance and Duncan's multiple range test for comparing the means.
Findings: The type of SOD enzyme was detected as Copper-zinc superoxide dismutase (Cu/Zn-SOD). There was no significant difference between different treatments of metals between two regions, and no interaction was observed between metal factor, concentration, and type of region. A strong inhibitory effect was observed in the presence of HgCl₂ solution and a weak inhibitory effect was observed in the presence of ZnSo₄, FeSo₄, and MgCl₂ solutions.
Conclusion: Copper, manganese, and cobalt ions significantly increase the activity of the superoxide dismutase, while monovalent ions such as sodium and potassium have little effect on increasing SOD activity and the activity of the antioxidant enzymes of avicennia marina leaf from Khamir port in the Persian Gulf and Sirik in the Gulf of Oman is not different.

The survey of the fish assemblage in the planned place to establish artificial reefs in the western and eastern bays of Jask was carried out in the winter and spring of 2024. Sampling was done by Gillnet and Trap methods in 4 stations located in the western bay and eastern bay of Jask at a depth of 10 to 30 meters. 68 aquatic species (60 fishes, 5 crabs, 2 oysters, and 1 shrimp) were sampled and recorded. Of these, Nemipterus japonicus (32.6 %) was the most abundant, Saurida tumbil (12.6 %), Anodontostoma chacunda (12.5 %), Ilisha megaloptera (9.8 %), Scomberoides tol (6.4 %), Sphyraena putnamae (4.1 %), Lactarius lactarius (2.6 %), Muraenesox bagio (2 %), Pomadasys kaakan (1.9 %), Otolithes ruber (1.6 %) located in the next rank. The average catch per unit of effort of gillnet was 45±10.2 kg/piece×hour and for Trap 7.3±4.2 kg/trap×day. In this research, it was found that the population of species related to artificial reefs, such as Epinephelus coioides , Lutjanus johnii , and Lethrinus nebulosus were relatively low, and mainly below the maturity size, it seems that the stocks of this group of fish need to be enhanced. Therefore, it is recommended to consider the target species in the design of the structure and arrangement of the artificial reefs, on the other hand, the shelter and protective aspects of the artificial reefs for the reef-dependent juvenile also be considered.