Struktur Komunitas Zooplankton di Muara Sungai Serang, Jogjakarta - Bayu A Pranoto; Ambariyanto Ambariyanto; Muhammad Zainuri (Marine Science Department Diponegoro University, 2005)
Zooplankton adalah salah satu komponen dalam rantai makanan yang diukur dalam kaitan dengan nilai produksi suatu ekosistem. Hal ini dikarenakan zooplankton berperan ganda baik sebagai konsumen satu maupun konsumen dua, dimana merupakan rantai penghubung di antara plankton dan nekton. Penelitian ini bertujuan untuk mengetahui struktur komunitas zooplankton di perairan muara Sungai Serang Yogyakarta. Metode penelitian yang digunakan adalah studi kasus. Penentuan stasiun sampling menggunakan metode pertimbangan (purposive sampling method). Pengolahan data meliputi kelimpahan, indeks keanekaragaman, indeks keseragaman, indeks dominansi, dan indeks dispersitas Morisita. Parameter perairan yang terukur suhu, salinitas, kecerahan, kecepatan arus, kedalaman, derajat keasaman (pH), DO, nitrat, dan fosfat. Hasil penelitian berdasarkan tanggal samplingdiperoleh kelimpahan rata-rata zooplankton berkisar antara 6.704-36.427 sel/L dengan indeks keanekaragaman 1,16-1,78; indeks keseragaman 0,75-0, 95; dan indeks dominansi 0,13-0,31. Sedangkan hasil penelitian berdasarkan stasiun diperoleh kelimpahan rata-rata zooplankton berkisar antara 10.952-31.669 sel/L dengan indeks keanekaragaman 1,17-1,65; indeks keseragaman 0,76-0,95; dan indeks dominansi 0,13 - 0,21.Berdasarkan hasil penelitian diperoleh hasil, bahwa genus zooplankton yang memiliki sebaran luas pada setiap stasiun (dominan) adalah genus Trigriopus, Nauplius, Pseudocalanus (Crustacea), Brachionus, Plerodina (Rotatoria). Berdasarkan hasil penelitian diperoleh kesimpulan bahwa zooplankton yang terdapat di perairan muara Sungai Serang Yogyakarta terdiri dari 6 kelas dan 21 genus. Sedangkan dilihat dari nilai indeks keanekaragaman dan keseragaman diketahui bahwa muara Sungai Serang termasuk daerah yang memiliki komunitas zooplankton yang beragam dan didominasi oleh kelas Crustacea.Kata kunci: struktur dan indeks komunitas, zooplankton, estuarinZooplankton is one of the components in the food chain especially in relation to the production of an ecosystem. This is due to the fact that zooplankton play both as first and second consumer. The objective of this study was to investigate the community structure of zooplankton within Serang River estuary, Yogyakarta. The research was based on a case study, while sampling was done by purposive sampling method. The abundance, variety index, diversity index, dominancy index, and dispersity index were calculated based on the data collected.. The water parameter measured temperature, salinity, transparency, current velocity, pH, dissolvedoxygen, nitrate, and phospate. The result showed that based on the date of sampling the average of zooplankton abundance were ranged between 6704 - 36427 cell/L with variety index range between 1,16-1,78; diversity index were ranged between 0,75-0,95; and dominancy index were ranged between 0,13-0,31. While the results based on sampling station of the average of zooplankton abundance was range between 10.952 - 31.669 cell/L with variety index were ranged between 1,17-1,65; diversity index were ranged between 0,76-0,94; and dominancy index range between 0,13-0,21. The most common genera of zooplankton found in sampling station were Tigriopus, Nauplius, Pseudocalanus (Crustacea), Brachionus, Pterodina (Rotatoria).There were 6 classes and 21 genera of zooplankton found in the estuary of Serang River, Yogyakarta. Based on the value of the indices, it suggest that this estuary has high diversity of zooplankton and dominated by class CrustaceaKey words : structure and community indices, zooplankton. estuary