Intertidal variation of macrobenthos in a saltmarsh habitat, Noakhali coast, Bangladesh

Ullah, Md. Akram; Hossain, Md. Shafawat; Hossain, M. Belal; Rahman, Mahbubur

doi:10.21608/ejabf.2020.117231

Intertidal variation of macrobenthos in a saltmarsh habitat, Noakhali coast, Bangladesh

Document Type : Original Article

Authors

10.21608/ejabf.2020.117231

Abstract

Macrobenthos play an important role in estuarine ecosystems by re-suspending the bottom layer of water bodies and elevating the nutrients, dissolved gases, and other materials between sediments and overlying water. The study aimed to measure the physicochemical parameter of the study area, to show the intertidal variation of macrobenthos, and to assess the relationship between environmental variables and benthic infauna of saltmarsh habitat along the Noakhali coast. Sediment infauna of saltmarsh was collected by using a hand-held mud corer having an area of 0.01 m²covering three tidal levels i.e., high tide level (HTL), mid-tide level (MTL), and low tide level (LTL). A little variation was observed among the environmental parameters across three tidal levels. A total of 16 taxa of benthic infauna belonging to Nereidae (37.60%), Nereidae-1 (12.60%), Chironomidae (24.56%), Cerambycidae (2.17%) were found in the three tidal levels. The Evenness index indicated the highest number of similar species were at the sub-stations of LTLs with a value of 1, and the lowest number of similar species was at the sub-station HTL1 with a value of 0.5712. The maximum Shannon diversity (HꞋ) index was found at the sub-station MTL2 with a value of 1.631 and the minimum was at the sub-station LTL2, LTL3 with a value of 0. Margalef species richness ranged from 0 to 0.8808 and the Equabilitty index (J) value from 0 to 0.8808. The diversity profile was high (α=14) at the mid-tide level. The Simpson (1-D) and DO, Shannon ( HꞋ), Margalef, and temperature were significantly correlated (p < 0.05). Again, almost all diversity indices showed a strong correlation with temperature (0.75 ≤ r <1). The information generated here can be used to measure the impact of pollution, to conserve the biodiversity of the study area, and can also be used for further studies.

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