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Title:	Contribution of tropical macroalgae to ecological services within coastal blue carbon ecosystems
Authors:	Natasha Arina Mohd Izham (P94744)
Supervisor:	Mohammad Rozami, Dr.
Keywords:	Carbon Seagrasses Universiti Kebangsaan Malaysia -- Dissertations Dissertations, Academic -- Malaysia
Issue Date:	5-Oct-2022
Description:	Macroalgae are essential ecological engineers that help to maintain the productivity of marine ecosystems. However, the current increase in climate change effects would significantly affect the macroalgal growth and productivity. The aim of this study is to include initial measurements of the connectivity between the macroalgae carbon and sediments in the tropical seagrass meadow. The primary focus of this research was to determine the stocks of carbon (C) and nitrogen (N) in the macroalgae tissue as well as the production of calcium carbonate (CaCO3) that contributes to the sedimentation of the meadow. The research was carried out in the Sungai Pulai estuary and Sembilang Island, and the species involved were Jania adhaerens, Ulva reticulata and Halimeda opuntia. Few separate analyses were conducted, which are environmental DNA (eDNA) study, detection of C, N stocks, δ13C and δ15N, carbonate characterisation (acid leaching, Fourier transform infrared (FTIR), and Thermogravimetric analysis, TGA) and quantification of magnesium (Mg) and calcium (Ca) in the skeletal tissue by inductively coupled plasma - optical emission spectrometry (ICP-OES). The presence of macroalgal tissue fragments retained in the sediments was shown by eDNA analysis, pointing to macroalgal C burial in the meadows. The data from stable isotope analysis showed that macroalgae is one of the key contributors to the organic matter (OM) pool in the seagrass meadow. The standing biomass of J. adhaerens varied in a span of 13-months from 65 to 143 g DW m-2, whereby the tissue biomass (143 g DW m-2) and CaCO3 stocks (147 g CaCO3 m-2) were the highest in the inter-monsoon period. The nutrient (C and N) variation study showed that the C and N content was significantly higher (P < 0.05) in U. reticulata compared to J. adhaerens with a difference of 29% and 61% respectively. The results further showed that bulk tissues of J. adhaerens retained more of the 13C and 15N tracers than U. reticulata. FTIR analysis showed that J. adhaerens and H. opuntia predominantly secrete calcite and aragonite, respectively. Inductively coupled plasma - optical emission spectrometry (ICP-OES) analysis showed high mMg/Ca ratio (20.6 mol% MgCO3) with high Ca and Mg amounts in J. adhaerens, indicating it is a high Mg-calcite species. These findings shed light on the role of macroalgae in the carbon cycle within blue carbon habitat. The capability of both calcifying and non-calcifying macroalgae as carbon sources is described, providing more information into their function in ecosystem services in terms of organic carbon (OC) and CaCO3 production and burial. With a better understanding of the relevance of macroalgal carbon to the environment, more sustainable management of macroalgae may be implemented based on their ecological benefits.,Ph.D
Pages:	155
Call Number:	TA455.C3N338 2022 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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