Characteristics of <i>Meretrix meretrix</i> and mangroves in the main clam-producing area of Bagan Asahan, North Sumatra, Indonesia

Abstract. Purwoko A, Mulya MB, Basyuni M, Gandeseca S, Daulay UA, Mubaraq A. 2026. Characteristics of Meretrix meretrix and mangroves in the main clam-producing area of Bagan Asahan, North Sumatra, Indonesia. Asian J For 10 (1): r100118. https://doi.org/10.13057/asianjfor/r100118. The Bagan Asahan mangrove ecosystem is one of the east coast ecosystems of North Sumatra, Indonesia, with enormous potential, including the kepah (Meretrix meretrix). This research aims to analyze the morphological characteristics of kepah shells through morphometric studies, distribution patterns, and substrate C-organic content, and to assess the suitability of vegetation and ecosystems. Field observations were conducted over six months at three stations representing different dominant mangrove genera (Sonneratia, Avicennia, and Rhizophora). Shell morphometric analysis was performed by measuring the length, height, and thickness of each individual's shell at each station. Distribution was analyzed based on shell length and frequency patterns. A total of 646 clams were recorded, with an average density of 11.96 individuals m-2. Shell lengths ranged from 1.5 to 4.5 cm, with the most frequent size class between 2.70 and 2.99 cm, indicating dominance of small-sized individuals. The Morisita Index showed a grouped distribution pattern at all stations. Morphometric relationships among shell dimensions exhibited strong positive correlations (R²=0.91-0.96), indicating proportional growth. Substrate C-organic content ranged from 1.48% to 1.74%, falling within ranges suitable for clam habitat. Mangrove vegetation consisted of six genera, with Rhizophora showing the highest importance value index (127.06%) at the station with the highest clam density (14.94 individuals m-2). Mangrove characteristics are suitable for kepah habitat. Rhizophora genus are more closely associated with kepah than other mangrove genus in this region. These findings provide baseline ecological information to support sustainable management of mangrove ecosystems and clam resources in this key production area. Therefore, Rhizophora genus are recommended for the highest level of protection and enrichment, as they greatly support mussel sustainability in this main production area.