Assessment of Molluscan Diversity at Chandipur Beach, Balasore Coast, Odisha, India

Abstract

This study assessed the diversity, distribution and ecological characteristics of marine molluscs along Chandipur Beach on the Balasore coast of Odisha, India. Sampling was conducted in the upper, middle and lower intertidal zones during low tide. Molluscan specimens were collected through hand-picking, 1 m × 1 m quadrat sampling, sediment sieving and visual observations along transects. A total of 20 molluscan species belonging to two classes were recorded. Gastropoda included 14 species and represented 70% of total species richness, whereas Bivalvia included six species and represented 30%. The most abundant species were Tegillarca granosa (13.93%) and Cerithidea cingulata (12.4%). The Shannon-Wiener diversity index was 2.38, indicating moderate species diversity, while the Simpson diversity index was 0.89, suggesting low dominance by any single species. Evenness was 0.82, indicating a relatively uniform distribution of individuals among recorded species. The lower intertidal zone supported the highest species richness, whereas the upper intertidal zone showed lower diversity. Recorded water quality values included temperature (27.4°C), pH (8.1), salinity (31 ppt) and dissolved oxygen (6.2 mg/L). Pearson correlation analysis showed a positive relationship between dissolved oxygen and molluscan abundance. The findings indicate that Chandipur Beach supports a moderately diverse molluscan assemblage and provide baseline information for future ecological monitoring of intertidal molluscs at this coast.