جستجوی مقالات مرتبط با کلیدواژه "دریای مکران" در نشریات گروه "شیلات"

The Maximum Entropy Model (MaxEnt) is a high-performance machine learning algorithm that is used to investigate the presence of species and to forecast the possible distribution of a target species according to its maximum entropy under different conditions and to determine the habitat suitability of species. In the present study, habitat suitability modeling for Nemipterus japonicus in the Makoran region (northern shores of the Makran Sea) was performed using the Maximum Entropy Model (MaxEnt). For this purpose, the data obtained from the fishing of Nemipterus japonicus during the period of 2015 to 2019 recorded by the Chabahar Offshore Fisheries Research Center in five areas were used to find points of presence. Based on the results obtained from the model, the variables of sea surface temperature at night and day and chlorophyll a concentration were recognized as the most important parameters in identifying the suitable areas, including the Gowatr bay area. Also, the area under the curve index (AUC) was equal to 0.998, which indicates the high accuracy and efficiency of the model in identifying the most suitable areas of Nemipterus japonicus distribution. The obtained results can be used as an effective tool for effective evaluation of conservation strategies for sustainable yield of Nemipterus japonicus fish stocks.

Dunaliella sp. is from division of chlorophyte algae that has a global distribution and is abundantly reported in the coastal waters of Chabahar Bay. This algae is a euryhalin species which may support high temperatures and lack of Nitrogen conditions in the sea. Also as a response to environmental stresses it fluctuates pigment reserves specially the Beta-Carotene. The aim of this study was effects of salinity on growth, chlorophyll and β-carotene concentration in Dunaliella sp. In this study in beyond the separation and purification of Dunaliella sp. from seawater, the impact of different levels of salinity (0.5, 0.75, 1, 1.5, 2, 3 and 4 mol NaCl) on growth, the amount of chlorophyll and β- carotene were measured during a period of 4 weeks. Chlorophyll a, b and β-carotene contents were determined spectrophotometrically from algal pellets using 80% (v/v) acetone/water mixture. Results showed that the Dunaliella sp. in treatments of 0.5, 0.75, 1, 1.5, 2, 3 and 4 mol NaCl could grow, but the maximum growth of this algae and the maximum amount of β-carotene were observed in salinities between 1.5 to 2 mol NaCl (p<0.05). Parallel to growth of the algae the production of chlorophyll a and b was increased in all salinities treatments but their production causes a decrease in β- carotene production.