Distribusi Unsur Hara di Pesisir Desa Buruk Bakul, Kabupaten Bengkalis, Provinsi Riau - Sefni Hendris; Dessy Yoswaty (Departemen Ilmu Kelautan, Fakultas PerikanJurusan Ilmu Kelautan, Universitas Diponegoro, 2026)
Penelitian ini mengkaji bagaimana nitrogen (N), fosfor (P), dan karbon organik (C) tersebar di sedimen pesisir Desa Buruk Bakul, Bengkalis. Daerah ini sangat menarik karena punya gabungan ekosistem: muara, mangrove alami, area rehabilitasi mangrove, dan tambak udang. Fokus utama adalah mencari tahu bagaimana kandungan N, P, dan C organik berbeda-beda di berbagai tempat, dan apa pengaruh kegiatan manusia serta kondisi ekosistem terhadap unsur- unsur tersebut. Sampel diambil dari empat lokasi yang berbeda, lalu dianalisis di laboratorium menggunakan metode standar untuk mengukur kadar nitrat, amonia, fosfat, dan karbon organik. Data diolah dengan menghitung persentase unsur hara dan perbandingan C:N:P. Hasilnya, karbon (C) adalah unsur yang paling banyak ditemukan di semua lokasi. Kandungan C tertinggi ada di hutan mangrove (0,007884%). Nitrogen (N) paling tinggi di area tambak stasiun 4, diduga karena limbah pakan dan aktivitas budidaya. Sementara itu, fosfor (P) paling rendah, hanya sekitar 0,000003–0,000010%, dan cenderung terikat kuat pada sedimen. Perbandingan C:N:P menunjukkan ketidakseimbangan, khususnya di ekosistem mangrove. Ini mungkin disebabkan oleh banyaknya serasah yang kualitasnya kurang baik dan proses penguraian yang lambat. Di tambak udang, kadar nitrogen meningkat sehingga menurunkan rasio C:N. Area rehabilitasi menunjukkan akumulasi unsur hara yang masih rendah, menandakan ekosistemnya belum stabil. Perbedaan jenis ekosistem dan aktivitas manusia sangat memengaruhi sebaran unsur hara. Informasi tentang distribusi C, N, dan P ini penting sebagai dasar untuk mengelola kualitas lingkungan dan memantau kesehatan ekosistem pesisir di Bengkalis. This study aimed to analyze the distribution of nitrogen (N), phosphorus (P), and organic carbon (C) in the coastal sediments of Buruk Bakul Village, Bengkalis Regency, which consists of estuary, natural mangrove, mangrove rehabilitation, and shrimp pond ecosystems. The study focused on spatial variations of nutrients and the influence of anthropogenic activities and ecosystem conditions on N, P, and organic C content. Sediment samples were collected from four observation stations using purposive sampling and analyzed in the laboratory following APHA and SNI procedures for nitrate, ammonia, phosphate, and organic carbon determination. Quantitative descriptive analysis was performed by calculating nutrient percentages and C:N:P ratios. Results showed that carbon was the dominant component at all stations, with the highest value recorded in the mangrove forest (0.007884%). Nitrogen was highest in shrimp ponds due to feed waste and aquaculture activities, whereas phosphorus had the lowest concentration (0.000003–0.000010%) because of strong binding to sediments. The C:N:P ratios indicated significant imbalance, particularly in mangrove ecosystems, reflecting the dominance of low-quality litter and slow decomposition. Shrimp ponds showed increased nitrogen that lowered the C:N ratio, while the rehabilitation area had low nutrient accumulation in line with the developing ecosystem. So, nutrient distribution in sediments is strongly influenced by ecosystem type and human activities. These findings provide essential information for environmental management and monitoring of coastal ecosystem health in Bengkalis.