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Showing 3 results for Tidal Zone
Ghazaleh Bahmani, Mohammad Alavi-Yeganeh, Seyed Jafar Seyfabadi, Parviz Tavakoli-Kolor,
Volume 6, Issue 1 (6-2017)
Abstract
Settlement of benthic community depends on environmental conditions and interspecific reactions. The effect of substrates on the surface cover by the soft coral, Zoanthus sansibaricus, and the brown algae, Iyengaria stellata and their computational condition, was compared in the Hormuz Island by estimating of coverage area in 40 quadrates (50×50 cm). Z. sansibaricus is a dominant soft coarl (Zoanthid) species in Hormuz island coasts in the other side I. stellata considered as dominant macroalgea, most of year in area. Significant negative correlation (p<0.01; r = -0.607) revealed competition between two species in settlement on the two substrates. Soft coral with 61.7% coverage was dominant vs. 16.8% for brown algae on muddy-Rubble substrate, but on sandy-Rubble substrate, the brown algae was dominant with 37.8% coverage vs. 19.5% for the soft coral. It seems that better compitiunal conditions in settlement on unconsolidated substrate have some advantages for Z. sansibaricus on Muddy-rubble substrate.
Volume 10, Issue 3 (10-2022)
Abstract
Aims: Monitoring variations in macroalgal assemblages is a crucial issue for the preservation and management program of coastal waters. This study was conducted to determine the seasonal and spatial distribution patterns, and composition of macroalgal communities along the eastern coasts of Qeshm Island, Iran.
Materials & methods: Seasonal sampling was conducted at three different sites of different tidal levels on the eastern coasts of Qeshm Island. Random samples of macroalgae were collected at three stations, seasonally. The species were identified and the dry weight of each species was used to calculate the macroalgae abundance. The Species richness and the Diversity indices were calculated to evaluate the distribution pattern and composition of the macroalgal community.
Findings: As a result, 51 species (4 Chlorophyta, 21 Phaeophyta, and 26 Rhodophyta) were identified. The seasonal and spatial dominant species were found to be Padina sp. and Hypnea sp., and a distribution pattern was seen to have increasing macroalgal biomass from the upper to lower intertidal level. The sampling sites shared more than 50% similarity of their macroalgal species, indicating a relatively homogeneous distribution. The highest (18.1±4.3 gr drywt m-2) and lowest (8.27±2.1 gr drywt m-2) mean of total seaweed biomass were recorded in winter and summer, respectively.
Conclusion: The assemblage composition of macroalgae significantly differs between hot and cold seasons, and there was no substantial compositional variation of seaweeds communities along the tidal gradient. The macroalgal distribution was largely homogeneous with no significant difference among the research areas at sampling seasons.
Mohammad Rreza Taherizadeh, Zohre Barkhovdari Ahmady, Fatemeh Shayesteh, Mohsen Gozari,
Volume 14, Issue 2 (5-2025)
Abstract
In this rese
In this research, the sediments of Bandar Abbas and Tiab estuary areas in Hormozgan province were conducted to determine the amount of heavy metal contamination (iron, copper, lead, zinc and nickel). Sampling of the sediments of these areas was done to determine the enrichment index and geochemical index using grab, and the flame atomic absorption device was used to determine the concentration of heavy metals. The results based on the mean (M ± SD) shows that the concentrations of the studied elements in different stations were significantly different from each other (P<0.05). So that in terms of the concentration of elements studied by FAO/WHO global standard in Bandar Abbas region (nickel 328.13±139.34, zinc 175.68±50.92, copper 0.0086±0.002, lead 12.67± 81.79 and iron 17520±691.21 μg/g) compared to Tiab region (nickel 1065.56±71, zinc 367.74±23, copper 0227±0.003, lead 72/19±60 123 and iron 35176 ± 872.38 µg/g) exhibited less contamination. The results of the enrichment factor of metals in iron and copper without enrichment, zinc with moderate enrichment, lead with relatively strong enrichment and nickel with severe enrichment, and in terms of Müller's geochemical index, the degree of soil pollution in the category of non-contaminated soils, with nickel component have a moderate degree of pollution. The pollution situation in Tiab region is more severe compared in Bandar Abbas region due to various reasons such as the presence of shrimp breeding sites, urbanization development, industry, agriculture and also due to the unprincipled oil activities that are carried out on the coasts. |