Diversity and Distribution of Gastropods in the Intertidal Zone of Banyu Meneng Beach, South Malang: a Preliminary Inventory Based on Zoning and Substrate Type Keanekaragaman dan Distribusi Gastropoda di Zona Intertidal Pantai Banyu Meneng, Malang Selatan: Inventarisasi Awal Berdasarkan Zonasi dan Tipe Substrat

Abstract

The intertidal zone is a dynamic coastal ecosystem characterized by environmental fluctuations caused by tidal cycles that influence the structure of benthic communities, including gastropods, within benthic ecology. However, baseline data on the diversity and distribution of gastropods in the intertidal zone of Banyu Meneng Beach, South Malang, remain limited and have not been documented. This study aims to inventory gastropod species and analyze distribution patterns based on intertidal zoning and substrate types. The research was conducted in November 2025 using a field survey method with a line transect approach placed parallel to the shoreline across three intertidal zones: upper, middle, and lower. Observations were conducted using 1 × 1 m quadrats on rocky and sandy substrates to record gastropod species and abundance. The results showed that 9 gastropod species belonging to 8 families were identified, with Turbinidae as the most dominant family (2 species). Species distribution exhibited a zonation pattern, where the middle intertidal zone contained the highest diversity with 7 species, while the upper and lower zones hosted only 1 species. Based on substrate type, rocky substrates supported diversity with 7 species, whereas sandy substrates were inhabited by only 2 species. Diversity index analysis showed a Shannon–Wiener diversity index (H') of 2.03 (moderate), Simpson dominance index (D) of 0.16 (low dominance), evenness index (E) of 0.92 (high evenness), and Margalef index (R) of 2.48 (moderate). Overall, intertidal zonation and substrate type play a role in shaping the gastropod community structure at Banyu Meneng Beach.