Identifikasi Zooplankton di Perairan Bagian Timur Laut Sumatera Berdasarkan Metode Konvensional dan e-DNA

Abstract

Zooplankton merupakan hewan air yang seluruh pergerakan hidupnya tergantung oleh arus dan merupakan salah satu tiang penopang kehidupan dalam bioekosistem laut. Keanekaragaman dan kelimpahan zooplankton dapat menjadi barometer penting untuk mengetahui kondisi ekologi perairan seperti kesuburan dan keseimbangan perairan sehingga perlu adanya survei untuk mengetahui keberadaan dan kelimpahan plankton di perairan bagian timur laut Sumatera. Penelitian ini bertujuan mengidentifikasi zooplankton di perairan bagian timur laut Sumatera dengan menggunakan metode konvensional dan metode e-DNA, mengetahui perbedaan komposisi dan struktur komunitas zooplankton metode konvensional antara pelabuhan, area pantai dekat pelabuhan, serta area lepas pantai di perairan bagian timur laut Sumatera. Identifikasi konvensional dilakukan dengan pengamatan mikroskopis berdasarkan buku “Illustration of The Marine Plankton of Japan” oleh Isamu Yamaji tahun 1979. Sementara itu, analisis e-DNA dimulai dari ekstraksi DNA, amplifikasi dengan PCR, elektroforesis, hingga sekuensing. Analisis zooplankton dengan metode konvensional berhasil mengidentifikasi 14 kelas meliputi Acantharia, Appendicularia, Bivalvia, Copepoda, Eurotatoria, Gastropoda, Globothalamea, Malacostraca, Oligotrichea, Polychaeta, Polycystina, Sagittoidea, Teleostei, dan Thecostraca dengan 31 genera dan 31 spesies. Persebaran kelimpahan zooplankton di perairan bagian timur laut Sumatera area pelabuhan, pantai dekat pelabuhan, dan lepas pantai tidak berbeda signifikan dengan nilai berturut-turut sebesar 2214,965 ind/l, 2262,485 ind/l, dan 1674,984 ind/l serta spesies yang paling banyak ditemukan yaitu kelompok nauplius dan Tintinnopsis sp. Analisis zooplankton dengan metode e-DNA berhasil mengidentifikasi 1.085 OTUs (Operational Taxonomic Units) yang termasuk dalam 20 kelas meliputi Appendicularia, Arachnida, Bacillariophyceae, Branchiopoda, Clitellata, Copepoda, Crustacea, Cubozoa, Eurotatoria, Gastrotricha, Hexacorallia, Hoplonemertea, Hydrozoa, Malacostraca, Maxillopoda, Ostracoda, Polychaeta, Scyphozoa, Tentaculata, dan Trematoda dengan genera sebanyak 127 serta spesies sebanyak 184.

Zooplankton are aquatic animals whose entire movement relies on water currents and serve as one of the pillars supporting life in the marine bioecosystem. The diversity and abundance of zooplankton can serve as important indicators of the ecological condition of waters, such as productivity and ecological balance. Therefore, surveys are necessary to determine the presence and abundance of plankton in the northeastern waters of Sumatra. This study aims to identify zooplankton in the northeastern waters of Sumatra using both conventional and environmental DNA (e-DNA) methods, as well as to examine the differences on composition and community structure of zooplankton (based on the conventional method) among port areas, coastal areas near the port, and offshore areas. Conventional identification was carried out through microscopic observation based on the book Illustration of The Marine Plankton of Japan by Isamu Yamaji (1979). Meanwhile, the e-DNA analysis involved DNA extraction, amplification via PCR, electrophoresis, and sequencing. Zooplankton analysis using the conventional method successfully identified 14 classes, including Acantharia, Appendicularia, Bivalvia, Copepoda, Eurotatoria, Gastropoda, Globothalamea, Malacostraca, Oligotrichea, Polychaeta, Polycystina, Sagittoidea, Teleostei, and Thecostraca, comprising 31 genera and 31 species. The distribution of zooplankton abundance in the northeastern waters of Sumatra between the port area, nearby coastal area, and offshore area showed no significant difference, with values of 2214.965 ind/l, 2262.485 ind/l, and 1674.984 ind/l, respectively. The most commonly found species were nauplius and Tintinnopsis sp. Zooplankton analysis using the e-DNA method successfully identified 1,085 OTUs (Operational Taxonomic Units) belonging to 20 classes, including Appendicularia, Arachnida, Bacillariophyceae, Branchiopoda, Clitellata, Copepoda, Crustacea, Cubozoa, Eurotatoria, Gastrotricha, Hexacorallia, Hoplonemertea, Hydrozoa, Malacostraca, Maxillopoda, Ostracoda, Polychaeta, Scyphozoa, Tentaculata, and Trematoda, with 127 genera and 184 species identified.