Tujuan Dari Penelitian Ini Yaitu Untuk Mengetahui Hubungan Fosfat Dan Nitrat Dengan Kelimpahan Fitoplankton Di Perairan Muara Pelabuhan Tengkayu II Kota Tarakan. Pengukuran Kualitas Air Dilakukan Di Lokasi Penelitian Dan Analisis Nitrat Dan Fosfat, Serta Identifikasi Fitoplankton Di Laboratorium Kualitas Air Fakultas Perikanan Dan Ilmu Kelautan Universitas Borneo Tarakan.
Penelitian Ini Dilaksanakan Di Perairan Pelabuhan Tengkayu II Kota Tarakan Dari Bulan September 2010 - Februari 2011. Pengambilan Sampel Dilakukan Di Perairan Pelabuhan Tengkayu II Tarakan Sebanyak Sembilan Titik Yang Berbeda. Tahapan Kerja Yang Dilakukan Meliputi Identifikasi Fitoplankton, Analisa Fosfat Dan Nitrat Dengan Menggunakan Formulasi Kelimpahan, Dan Analisis Regresi Berganda.
Di Muara Pelabuhan Perikanan Tengkayu II Tarakan Nitrat Tidak Berpengaruh Nyata Terhadap Kelimpahan Fitoplankton. Sedangkan Fosfat Berpengaruh Nyata Terhadap Kelimpahan Fitoplankton.
Kata Kunci: Fosfat Dan Nitrat, Fitoplankton, Pelabuhan Tengkayu II Tarakan

The Purpose Of This Study Is To Determine The Relationship Of Phosphate And Nitrate By Phytoplankton Abundance In The Waters Of Muara Port Of Tarakan City Tengkayu II. Measurement Of Water Quality Conducted On Site Research And Analysis Of Nitrate And Phosphate, And The Identification Fitplankton On Water Quality Laboratory Of The Faculty Of Fisheries And Marine Sciences University Of Borneo Tarakan. The Research Was Conducted In The Waters Of Port Tengkayu II City Of Tarakan Of The Month September 2010 - February 2011. Samples Were Taken In The Waters Of Port Tengkayu II Tarakan Nine Different Points. Stages Of The Work Done Includes The Identification Of Phytoplankton, Phosphate And Nitrate Analysis Using The Formulation Of Abundance, And Multiple Regression Analysis. There Was No Relationship Between Nitrate Content And The Abundance Of Phytoplankton. While There Is A Correlation Between Phosphate Content With The Abundance Of Phytoplankton, Where The High Concentration Of Phosphate May Be One Factor That Can Increase The Abundance Of Phytoplankton. Keywords: Phosphate And Nitrate, Phytolankton, Port Tengkayu II Tarakan