Document Type : Original Manuscript
Authors
1 Department of Marine Biology, Faculty of Marine Science and Oceanography, Khorramshahr University of Marine Science and Technology, Khorramshahr, Iran.
2 Departments of Biology and Stock Assessment, Iranian Fisheries Sciences Research Institute, Tehran, Iran.
3 Department of Marine Biology, Faculty of Marine Sciences, Chabahar University of Maritime and Marine Sciences, Chabahar, Iran.
Abstract
To study the effects of monsoon on the richness and seasonal changes in the density of crabs in the intertidal area of the southern coast of Sistan and Balouchestan province, sampling was carried out in 2013 (based on the intensity of the monsoon) in three seasons: pre-monsoon, monsoon and post-monsoon using quadrats (Dimensions 50x50 cm and depth 10 cm), in 5 different stations. During the research, organic matter, salinity and temperature were also measured. Altogether, in this study, 17 species belonging to 10 families and 15 genera were identified. Based on the two-way ANOVA analysis results, a significant difference in brachyuran crab density and diversity was observed between the three seasons. The lowest species richness and density between the three seasons were recorded during the monsoon due to environmental stress. On the other hand, due to the presence of favorable environmental conditions for crabs, the highest density and species richness were observed in the prior and post-monsoon seasons. The statistical comparison of density in different stations showed that due to the significant relationship between density, grain size, and other environmental conditions, Jazireh Krahang and Gowater stations have the highest amount of TOM throughout the year, the presence of mud substrate and mangrove ecosystem has the highest species richness and density. In contrast, the lowest density has been recorded at Tiss and Bris. Monsoons can affect the ecology of living organisms differently. Totally, Monsoons can cause a decrease in the density and abundance of crabs during monsoon season in the intertidal zone due to their extensive effects on environmental conditions such as the content of organic matter and substrate conditions.
Keywords
Main Subjects
)