Morphological and molecular monitoring of fishes in the waters of mangrove ecosystems

Abstract

BACKGROUND AND OBJECTIVES: Mangroves are primarily found along Sumatra's east coast in Aceh and North Sumatra, Indonesia. Fish communities and other marine life are supported by mangrove forests, which are extremely productive ecosystems. This study used morphological and 16 small subunit ribosomal ribonucleid acid barcodes to track fish diversity in waters surrounding mangroves. The study objectives were to integrate morphological identification with 16 small subunit ribosomal ribonucleic acid deoxyribonucleic acid barcoding to assess fish diversity in mangrove ecosystems along the east coast of North Sumatra and Aceh, Indonesia. METHODS: Study sites were selected in five locations, namely, Percut Sei Tuan, Belawan, Lubuk Kertang, and Pulau Sembilan in Sumatera Utara coast and Langsa in Aceh coast. Fish specimens were caught using gillnet and danish seines operated by the local fishermen. Morphological identification was performed based on standard taxonomic keys, and deoxyribonucleic acid barcoding using 16 small subunit ribosomal ribonucleic acid deoxyribonucleic acid marker was applied to validate species identification. FINDINGS: Seventy fish specimens were 70 collected, and 62 species and 39 families were morphologically identified. Leiognathus equula (Leiognathidae) was found in all study sites, followed by Ambassis vachellii (Ambassidae), Pomadasys argenteus (Haemulidae), and Eleutheronema tetradactylum (Polynemidae) in four locations. Gerres filamentosus (Gerreidae), Terapon jarbua (Teraponidae), Sphyraena qenie (Spyraenoidae), and Elops machnata (Elopidae) were detected in three locations. ribosomal ribonucleic acid barcoding confirmed 17 of the fish species detected. Deoxyribonucleic acid barcoding using 16 small subunit ribosomal ribonucleic acid validated the identification of 17 species, confirming that morphological and molecular approaches are complementary in assessing fish diversity. Two species, Larimichthys crocea and Thunnus maccoyii, were found to be critically endangered and endangered, respectively. CONCLUSION: The combination of field surveys and 16 small subunit ribosomal ribonucleic acid barcoding provides a comprehensive assessment of the changes in fish species composition and abundance over time, allowing for the identification of vulnerable species and the development of effective conservation strategies. The findings highlight the importance of long-term monitoring, habitat conservation, and sustainable fisheries management to protect fish biodiversity in mangrove ecosystems along the east coast of North Sumatra and Aceh.