DISTRIBUSI DAN KEMELIMPAHAN FITOPLANKTON DI RAWA BIRU, MERAUKE

LANGGA SWARAS FAHAR, Dr. Tjut Sugandawaty Djohan

2013 | Skripsi | BIOLOGI

Rawa Biru merupakan ekositem amfibius. Pada musim kemarau berupa danau dangakal dan pada musim hujan berupa aliran sungai. Perubahan ekosistem akan direspon oleh fitoplankton dengan perbedaan distribusi dan kemelimpahannya. Penelitian ini mempelajari distribusi dan kemelimpahan fitoplankton pada dan mempelajari faktor-faktor yang meregulasi. Pada penelitian ini sampel fitoplankton dicuplik di tiga lokasi sampling yaitu perairan Tempe permukaan, perairan Tempe dasar dan kanal pada musim kemarau 2011 dan awal musim hujan 2012, serta bak penampung atas dan bawah hanya diambil pada awal musim hujan. Pada setiap lokasi pengambilan sampel menggunakan modifikasi pencuplik air Van dorn ukuran 5 liter sebanyak 100 liter dengan 5 kali ulangan. Fungsional grup yang paling melimpah adalah alga unisel. Jenis yang paling melimpah adalah Staurastrum sp. 5295 ind. per 100 liter di perairan Tempe permukaan, 5057 ind. per 100 liter di perairan Tempe dasar, dan 645 ind. per 100 liter di kanal musim kemarau. Awal musim hujan 437 ind. per 100 liter di perairan Tempe permukaan, 426 ind. per 100 liter di perairan Tempe dasar, dan 3319 ind. per 100 liter di kanal. Jenis ini merupakan alga unisel anggota desmids. Banyaknya kelompok desmids yang ditemukan menandakan perairan rawa Biru kualitasnya baik. Nutrien di Rawa Biru pada musim kemarau dan awal musim hujan sama, sehingga pertumbuhan fitoplankton kontinum. Distribusi dan kemelimpahan fitoplankton di Rawa Biru diregulasi oleh interaksi predator-prey (top-down).

Rawa Biru is an amphibius ecosystem, in dry season this lake acted as shallow lake and midstream in rainy season. Distribution and abundance of phytoplankton influenced by environmental factor. The objective of this research were studied distribution and abundance of phytoplankton in Rawa Biru and the its regulation factor. The samples phytoplankton were collected seasonly, dry season 2011 and rainy season 2012. The samples were collected at three sampling stations, Tempe water coloum, and canal in dry and rainy. In water storage collected only in rainy season. In each sampling stations, water samples were collected with modification of Van dorn water sampler 5 L. Phytoplankton samples were collected 100 liter for it with 5 replicated each station. The dominant functional group were unicellular algae. The dominant species were Staurastrum sp. 5295 ind. per 100 liter in Tempe’s surface, 5057 ind. per 100 liter in Tempe’s sub surface, and 645 ind. per 100 liter in canal at dry season. At rainy season 437 ind. per 100 liter in Tempe’s surface, 426 ind. per 100 liter in Tempe’s sub surface, and 3319 ind. per 100 liter in canal This species are desmids unicellular algae. Abundance of the desmids is a indicator good water quality. Nutrient in Rawa Biru similar each season, phytoplankton growth is continous. Distribution and abundance phytoplankton in Rawa Biru regullated by predator-prey interaction (top-down).

Kata Kunci : Fitoplankton, ekosistem amfibius, top-down, desmids.