DISTRIBUSI KARBON ORGANIK DALAM SEDIMEN INTI DI PERAIRAN LEMBATA, LAUT FLORES

Abstract

Kondisi lingkungan dapat diketahui berdasarkan jejak karbon organik dalam sedimen inti. Penelitian bertujuan untuk mengetahui perubahan lingkungan saat sedimen terendapkan. Lokasi penelitian berada di perairan utara Pulau Lembata, Laut Flores. Bahan yang digunakan adalah sampel sedimen inti yang diambil menggunakan penginti jatuh bebas pada 7 (tujuh) lokasi dengan sayatan oles. Karakteristik sedimen bagian timur didominasi fragmen biogenik dan sedimen lebih halus. Bagian tengah memiliki komposisi relatif sama antara fragmen batuan dengan biogenik. Bagian barat didominasi oleh fragmen biogenik. Persentase material organik antara 2.496-11.133%, CaCO3 (karbonat) 16.365-79.910% dan total organik karbon 0.999-4.453%. Distribusi karbon organik dalam sedimen inti menunjukkan perubahan dinamis di wilayah perairan tengah dibandingkan dengan bagian barat dan timur. Perubahan distribusi karbon organik terjadi karena adanya perbedaan sumber asal sedimen, perbedaan morfologi dasar laut, perubahan kekuatan dinamika perairan, pemanfaatan kesuburan perairan, dan perbedaan produktivitas perairan saat material karbon organik terendapkan.
Kata kunci: sedimen, karbon organik, total organik karbon, perairan Lembata

Environmental conditions can be traced through recording the distribution of organic carbon content in core sediments. This study aims to determine environmental changes when sediment is deposited in Lembata waters. The research location is in the north waters of Lembata Island, Flores Sea. The materials used were core sediment samples taken using gravity core at seven locations. The study method uses a Loss On Ignition (LOI) procedure. The results of the analysis of the upper smear slide (0 cm). The eastern part is dominated by biogenic and sedimentary fragments which are finer than the western-central part, the middle part has a relatively similar composition between rock and biogenic fragments. in the dominant western part is a brightly colored material fragment. The change in the percentage of organic material is between 2,496-11,133%, the concentration of CaCO3 ranges from 16,365-79,910% and the concentration of TOC ranges from 0.999-4,453%. Distribution of organic carbon in core sediments from Lembata waters shows dynamic changes in the middle waters compared to the west or east. Changes in the distribution of organic carbon in Lembata waters occur due to differences in sources of sediment origin, differences in seabed morphology, changes in the strength of water dynamics, utilization of aquatic fertility, and differences in waters productivity when organic carbon material is deposited.
Keywords: sediment, organic carbon, total organic carbon, Lembata waters