HUBUNGAN ANTARA KANDUNGAN NITRAT DAN FOSFAT DENGAN KELIMPAHAN FITOPLANKTON DI PERAIRAN PULAU PARI, KEPULAUAN SERIBU
Authors: Rizqina Cahya , Sulardiono Bambang , Djunaedi Ali 
Published: September 2020

ABSTRAKKeberadaan fitoplankton dapat memberikan informasi mengenai kondisi suatu perairan, sedangkan nitrat dan fosfat mempengaruhi keberadaan fitoplankton untuk pertumbuhan dan transfer energi. Penelitian bertujuan untuk mengetahui jenis dan kelimpahan fitoplankton, mengetahui kandungan nitrat dan fosfat di perairan, serta hubungannya dengan kelimpahan fitoplankton dan mengetahui nilai indeks saprobitas perairan. Penelitian dilaksanakan pada bulan Mei – Juni 2016. Materi penelitian adalah sampel fitoplankton dan sampel air untuk uji nitrat dan fosfat. Metode pengambilan sampel secara purposive sampling. Sampling dilakukan sebanyak tiga kali pada 3 stasiun. Pengambilan sampel fitoplankton menggunakan jaring plankton dengan metode sampling aktif. Sampel fitoplankton diawetkan menggunakan lugol iodine 2-3 tetes sebelum diidentifikasi di laboratorium. Uji kandungan nitrat dan fosfat dilakukan dengan skala laboratorium. Analisa data dilakukan menggunakan Microsoft Excel 2013. Hasil penelitian menunjukkan kandungan nitrat di Pulau Pari berkisar antara 0,069 – 0,088 mg/l. Kandungan nitrat tergolong cukup optimal bagi pertumbuhan fitoplankton. Kandungan fosfat berkisar antara 0,004 – 0,006 mg/l. Kandungan fosfat tergolong rendah namun masih dapat ditolerir oleh fitoplankton. Kelimpahan fitoplankton berkisar antara 1774 – 3657 ind/l. Koefisien korelasi (r) sebesar 0,98 dan 0,905 artinya antara kandungan nitrat maupun fosfat dengan kelimpahan fitoplankton memiliki hubungan yang kuat. Nilai SI berkisar 1,28 – 1,43 dan nilai TSI berkisar 1,64 – 2,66 hal ini menunjukkan bahwa kualitas perairan Pulau Pari, dikategorikan dalam tingkat saprobitas oligosaprobik yaitu tercemar ringan sampai belum tercemar Kata kunci: Nitrat dan Fosfat, Kelimpahan Fitoplankton, Indeks Saprobitas, Pulau Pari, Kepulauan Seribu                                                                                           ABSTRACTThe existence of phytoplankton in the waters can provide information about water quality, while nitrates and phosphates affecting the availability of phytoplankton for growth and energy transfer. This research aims to know phytoplankton abundance and kinds of phytoplankton, find out the levels of nitrates and phosphates in the water and its connection with the abundance of phytoplankton, and find out saprobics index water. The research was conducted in May – June 2016. Material used in research was sample of phytoplankton and water samples. Methods used field survey with purposive technique sampling. The activity of sampling done in three times in 3 different stasions. Collection of phytoplankton sample using plankton net and active sampling method.  Phytoplankton samples preserved using 2-3 drops lugol's iodine before identified in the laboratory. Water samples to be tested it is nitrate and phosphate contents in laboratory scale. Data analysis research was done using Microsoft Excel 2013. This research shows the content of nitrate is about 0.069 to 0.088 mg/l. Nitrate content is optimal for growth of phytoplankton and phosphate is about 0.004 to 0.006 mg/l. Classified quite high but still can be tolerated by the phytoplankton. Phytoplankton abundance ranges from 1774 - 3657 ind/l. The correlation coefficient (r) between nitrate and phytoplankton abundance is 0,98 then between phosphate and phytoplankton abundance is 0,902. The result means both of them have a strong correlation. SI values from 1,28 to 1,43, and TSI value from 1,64 to 2,66 this show that water quality in Pari Island Thousand Island is categorized into oligosaprobic which is lightly polluted to uncontaminated.                                                                            Keywords: Nitrate and Phosphate, Phytoplankton abundance, Saprobic Index, Pari Island, Thousand Island