Sains Malaysiana 44(7)(2015): 941–945

Influence of Monsoon on the Distribution of Organic Carbon in Inner Continental Shelf Core Sediments, South China Sea, Malaysia

(Pengaruh Monsun ke atas Taburan Karbon Organik dalam Sedimen Teras Pelantar Benua Dalam

di Laut China Selatan, Malaysia)

PANG SWEE YUN¹, JURIFFAH ARIFFIN¹, HII YII SIANG^2,3 & NORHAYATI MOHD TAHIR^1,2*

¹Environmental Research Group, School of Marine and Environmental Science,Universiti Malaysia Terengganu, Mengabang Telipot, 21030 Kuala Terengganu, Terengganu Darul Iman, Malaysia

²Fellow Institute of Oceanography and Environment, Universiti Malaysia Terengganu, Mengabang Telipot, 21030 Kuala Terengganu, Terengganu Darul Iman, Malaysia

³School of Aquaculture and Fisheries Science, Universiti Malaysia Terengganu, Mengabang Telipot, 21030 Kuala Terengganu, Terengganu Darul Iman, Malaysia

Received: 4 August 2014/Accepted: 17 February 2015

ABSTRACT

Three short sediment cores (12-32 cm) from South China Sea off Southern Terengganu were collected during May (post-Northeast monsoon) and September (pre-Northeast monsoon) 2007. The concentration of total organic carbon (TOC) obtained ranged from 0.41-2.23 and 0.38-2.31% during post and pre-monsoon, respectively. TOC concentration was found to decrease with depth and distance from the coast and river mouth. In particular, station with close proximity to the coast exhibits most pronounced variation of TOC with depth. Besides spatial variation, it is noted that the seasonal variations also considerably affect the distribution and concentrations of TOC, where both near and offshore sampling stations showed significant variations in TOC content during May and September sampling. These findings suggest the importance of terrestrial organic carbon flux, physical mixing and seasonal variations in regulating the concentration and distribution of the organic carbon in the study area.

Keywords: Autochthonous organic carbon; fluvial transport; land-based organic matter; seasonal influence; Southern South China Sea

ABSTRAK

Tiga turus sedimen pendek (12-32 cm) telah diambil di Laut China Selatan dalam bulan Mei (pos-Monsun Timur Laut) dan September 2007 (pra-Monsun Timur Laut). Kepekatan jumlah karbon organik (TOC) yang diperoleh adalah antara 0.41-2.23% bagi pos monsun manakala bagi pra-monsun adalah antara 0.38-2.31%. Kepekatan TOC didapati berkurangan dengan jarak dari pesisir pantai dan muara sungai. Kepekatan TOC juga didapati berkurangan dengan kedalaman turus sedimen pada semua stesen, dengan stesen yang paling dekat dengan pesisir pantai mempamerkan perubahan kepekatan yang paling ketara. Perubahan musim juga memberi kesan kepada taburan dan kepekatan TOC dengan kedua-dua stesen berdekatan pesisir pantai dan luar pantai mempamerkan perbezaan kepekatan TOC yang signifikan pada musim Mei dan September. Penemuan ini menunjukkan bahawa fluks karbon organik daratan, percampuran fizikal dan perubahan musim adalah penting dalam mengawal kepekatan dan taburan karbon organik di kawasan kajian.

Kata kunci: Angkutan sungai; bahan organik daratan; karbon organik autokran; Laut China Selatan; pengaruh musim

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*Corresponding author; email: hayati@umt.edu.my