KOMPOSISI JENIS DAN KELIMPAHAN RELATIF FITOPLANKTON DI RANU KLAKAH, LUMAJANG, JAWA TIMUR: SPECIES COMPOSITION AND RELATIVE ABUNDANCE OF PHYTOPLANKTON IN RANU KLAKAH, LUMAJANG, EAST JAVA - Mukhammad Amrillah, Attabik; Kilawati, Yuni; Rizqa, Vylzah (JFMR (Journal of Fisheries and Marine Research), 2023)
Penelitian telah dilaksanakan di Ranu Klakah, Kabupaten Lumajang, Jawa Timur. Tujuan dari penelitian ini adalah untuk mengetahui komposisi jenis dan kelimpahan relatif fitoplankton di perairan Ranu Klakah, Kabupaten Lumajang. Stasiun pengambilan sampel ditentukan pada tiga titik yakni inlet, tengah (kawasan KJA), dan outlet. Pengambilan sampel dilakukan sebanyak 3 kali. Parameter yang diamati meliputi parameter fisika, kimia dan biologi. Parameter fisika dan kimia perairan yang diamati meliputi suhu, kecerahan, pH, DO, nitrat serta orthofosfat. Divisi fitoplankton yang ditemukan memiliki spesies terbanyak adalah Chlorophyta, Chrysophyta, dan Ochrophyta. Tetraspora sp yang termasuk divisi Divisi Chlorophyta memiliki kelimpahan yang paling tinggi jika dibandingkan dengan jenis spesies plankton lainnya. Data kualitas air diperoleh suhu perairan berkisar 27,6 – 28oC, kecerahan peraiaran berkisar 60 cm – 119 cm, nilai pH peraiaran 7, oksigen terlarut berkisar 7 – 7,8 mg/l, nitrat berkisar 0,23 – 1,04 mg/l, sedangkan orthofosfat didapatkan nilai 0,1 mg/l. Berdasarkan hasil penelitian yang telah dilaksanakan dapat disimpulkan bahwa wilayah perairan Ranu Klakah masih tergolong dalam perairan mesotrofik (perairan yang tingkat kesuburan sedang). Berdasarkan dari komposisi jenis dan kelimpahan fitoplankton dapat disimpulkan bahwa keanekaragaman jenis yang dimiliki Ranu Klakah masih tinggi.   The research was carried out in Ranu Klakah, Lumajang Regency, East Java. The purpose of this study was to determine the species composition and relative abundance of phytoplankton in Ranu Klakah, Lumajang Regency. Sampling site were determined at three points, namely inlet, middle (KJA area), and outlet. Sampling was carried out 3 times. Parameters observed included physical, chemical and biological parameters. Physical and chemical parameters of the waters observed included temperature, brightness, pH, DO, nitrate and orthophosphate. Phytoplankton divisions that were found to have the most species were Chlorophyta, Chrysophyta, and Ochrophyta. Tetraspora sp which belongs to the Chlorophyta Division has the highest abundance when compared to other types of plankton species. Water quality data obtained water temperature ranged from 27.6 – 28oC, water brightness ranged from 60 cm – 119 cm, water pH value was 7, dissolved oxygen ranged from 7 – 7.8 mg/l, nitrate ranged from 0.23 – 1.04 mg/l, while orthophosphate obtained a value of 0.1 mg/l. Based on the results of the research that has been carried out, it can be concluded that the waters of Ranu Klakah are still classified as mesotrophic. Based on the species composition and abundance of phytoplankton, it can be concluded that the species diversity of Ranu Klakah is still high.