SEBARAN STRUKTUR SEDIMEN, BAHAN ORGANIK, NITRAT DAN FOSFAT DI PERAIRAN DASAR MUARA MORODEMAK

Abstract

Padatnya aktivitas manusia di muara sungai Tuntang Morodemak dapat memberikan sumbangan terbesar dari proses sedimentasi di muara dan pesisir pantai. Kondisi ekologis ini dikhawatirkan akan semakin menurun, akibatnya keseimbangan dinamika muara, seperti kehidupan biota dasar perairan misalnya gastropoda, bivalvia, dan makrozoobenthos memegang peranan penting dalam proses mendaur ulang bahan organik dan proses mineralisasi serta menduduki beberapa posisi penting dalam rantai makanan akan terganggu. Tujuan penelitian ini adalah mengetahui sebaran struktur partikel sedimen, bahan organik, nitrat, dan fosfat sedimen serta mengetahui hubungan antara partikel sedimen dengan bahan organik, nitrat, dan fosfat sedimen di perairan muara sungai Tuntang Morodemak. Metode yang digunakan menggunakan metode purposive sampling. Analisis data menggunakan metode Regresi Korelasi. Hasil yang diperoleh adalah sebaran struktur partikel sedimen di muara sungai Tuntang Morodemak terdiri dari pasir (0.5-0.0625 mm), lumpur (0.0625-0.0039 mm), dan liat (<0.0039 mm). Kandungan pasir terbanyak diperoleh di stasiun 1 dengan prosentase 4%, lumpur terbanyak diperoleh di stasiun 8 dengan prosentase 80%, dan liat terbanyak diperoleh di stasiun 6 dengan prosentase 61.56%. Sebaran bahan organik dan fosfat sedimen terbanyak di stasiun 1 dengan nilai 13.20% dan 7.13 mg/gr, sebaran nitrat sedimen terbanyak di stasiun 8 dengan nilai 22.13 ppm. Hubungan partikel sedimen dengan bahan organik yang mempunyai hubungan paling kuat adalah fraksi pasir dengan nilai koefisien korelasi 0.88. Hubungan partikel sedimen dengan nitrat tidak ada yang memiliki keeratan yang kuat antara pasir, liat, dan lumpur. Hubungan partikel sedimen dengan fosfat yang memiliki hubungan paling kuat adalah fraksi pasir dengan nilai koefisien korelasi 0.71.

Density of human activities at the estuary of Tuntang Morodemak river is providing the biggest contribution of the sedimentation process in the estuarine and the coastal region. Sedimentation process will affect the ecological condition in the area of the estuary. When the ecological condition is decreasing, it will disrupt the balance of the estuary, for example the condition of aquatic biota, such as gastropods, bivalves, and macrozoobenthos which has the most important role in food chain, recycling process, and mineralization process. The purpose of the research is to find the distribution and the correlation between sediment particles, organic materials, nitrate, and sedimentary phosphate in the estuary of Tuntang Morodemak. The method used in this research was purposive sampling method. The regression and correlation method is used to analyze the data. The results showed that the distribution of sediment particles in Tuntang Morodemak consists of sand (0.5-0.0625 mm), silt (0.0625-0.0039 mm), and clay (<0.0039 mm). Station 1 has the biggest amount of sand, it was 4%. Station 8 has 80% of silt which is the biggest amount of all while station 6 has the highest presentation of clay (61.65%). The distribution of organic material and sedimentary phosphate in station 1 was the highest (13.20% and 7.13 mg/gr), while station 8 has the biggest amount of sediment nitrate (22.13 ppm). The strongest correlation between sediment particle and material organic was sand fraction which has 0.88 of correlation coefficient. Sediment particle and nitrate did not have a strong correlation with sand, silt, and clay while the strongest correlation between sediment particle and phosphate was sand fraction which has 0.71 of correlation coefficient.