Showing 3 results for Ghodrati Shojaei
Parima Hajializadeh, Mohsen Safaei, Reza Naderloo, Mehdi Ghodrati Shojaei,
Volume 10, Issue 2 (Spatial Issue on Persian Gulf 2021)
Abstract
This study was conducted to determine the temporal and spatial distribution of Opusia indica in the Hara Biosphere Reserve in the Persian Gulf. Seasonal sampling (four seasons) was performed from winter 2019 to autumn 2019. Sampling was done in five regions and three habitats within each region using metal quadrats with dimensions of 25 × 25 cm. In each habitat, environmental parameters including temperature, salinity, dissolved oxygen, pH along with organic matter and grain size were measured. The results showed that the abundance and biomass of Opusia indica have decreasing trend with increasing habitat complexity. Seasonally, the highest abundance and biomass were observed in winter and autumn, respectively, and the lowest abundance and biomass were observed in spring. There was a significant difference between habitats and seasons (p <0.05). Salinity showed a significant difference between habitats but didn't have seasonal changes. While temperature didn't show a significant difference between habitats, but it had seasonal changes. There was a significant difference between dissolved oxygen levels and pH between habitats and seasons. Significant changes were observed between habitat and seasons in sediment grain size, while the amount of organic matter showed only differences between habitats. Also, analysis of Kendall correlation between environmental factors (temperature, salinity, dissolved oxygen and pH) with abundance and biomass showed that there was a significant correlation between these environmental factors but no significant correlation was observed between abundance and biomass with the amount of organic matter. The results help to better understand the situation of this species in the mangroves ecosystem.
Rahil Nozarpour, Mehdi Ghodrati Shojaei, Reza Naderloo,
Volume 11, Issue 4 (12-2022)
Abstract
We studied the abundance, biomass and diet of Platevindex aff. tigrinus in the Hara Biosphere Reserve in the Persian Gulf. The seasonal sampling (two seasons) was conducted in winter 2018 and summer 2019. Samples were collected from six sites in Qeshm Island and Bandar Khamir. To determine the effect of environmental parameters on distribution of the species, temperature, salinity, pH, sediment grain size, total nitrogen and organic carbon were measured at each site. The results showed that the abundance of P. tigrinus was significantly higher in the winter compare to summer season. However, there was no significant difference in the biomass of the species between seasons. The PCA results showed that salinity, temperature and sediment grain size contributed to the separation of between seasons. The pH and total nitrogen followed the similar pattern in different sites and seasons. Although, temperature, salinity, sediment grain size, and organic carbon showed difference between seasons. The results showed that salinity and temperature were two important parameters in the distribution of the species during both seasons. The species was mainly feeding on the microphytobenthos during winter and on the sediment organic matter during summer.
Omid Shayanfar, Mehdi Ghodrati Shojaei, Siamak Behzadi,
Volume 12, Issue 2 (4-2023)
Abstract
The purpose of this research is to investigate the relative importance of Avicennia marina organic matter in the feeding of Ilisha melastoma fish in the Mangrove Biosphere Reserve; It was stable isotope approach. Three primary food sources including mangrove tree leaves, microphytobenthos and suspended organic particles were analyzed isotopically. The samples of primary food sources and fish are converted into pure and simple gases such as CO, CO2 and N2 after minimizing the size and turning into powder. Then the identified isotope ratios are compared with a measured standard and the exact amount of isotope formed in the sample is obtained. In this research, sampling was done seasonally in August in the summer season and February in the winter season of 2019 in the mangrove ecosystems of Bandar Khmer, Hormozgan province.In the summer season, the average stable carbon isotope of primary food sources fluctuated from -28.07 units per thousand for mangrove leaves to -13.58 units per thousand for microphytobenthos.This average in the winter season was obtained from -28.05 units per thousand for mangrove leaves to -13.54 units per thousand for microphytobenthos.The average stable nitrogen isotope of primary food sources in the summer season fluctuated from 1.44 units per thousand for microphytobenthos to 10.72 units per thousand for suspended organic particles.The results of this research showed that in the summer season, suspended organic particles with 63% and in the winter season, microphytobenthos with 45% play the most important role in providing the food needed by the small shemsk fish.