APPLICATION OF DUAL STABLE ISOTOPES IN INVESTIGATING FOOD WEB STRUCTURE OF A NATURALLY DISTURBED MANGROVE AREA OF KELANTAN DELTA, MALAYSIASyaizwan Zahmir Zulkifli, Aqilah Mukhtar, Azizul Aziz, Ferdaus Mohamat-Yusuff and Ahmad Ismail
The occurrence of megaflood may significantly alter the natural processes and overall condition in the impacted areas, including estuary locations receiving massive freshwater discharges from terrestrial areas to the sea. The present study is aimed to investigate the food web structure in Kelantan Delta (i.e., a naturally disturbed mangrove area) after the massive disturbance of 2014 megaflood. Various aquatic organisms were collected from the location and all samples were chemically treated according to standard procedures whereby the values of Î´13C and Î´15N ratios were determined by using an elemental analyser - isotope ratio mass spectrometry (EA-IRMS) instrument. The results subsequently showed that the Î´13C ranged between -31â° and -12â°, whereas the Î´15N ranged between 0.9â° and 14.8â°. Analyses of Î´13C and Î´15N values revealed four trophic levels whereby the value of Î´15N enrichment to distinguish different trophic levels was 3.5â°. With such amount of trophic levels, areas consistently disturbed would be characterized by short food chains making up their respective food webs. By having such process, Kelantan Delta would have a faster recovery process after any flood event. However, further investigation of the factors promoting population recovery after frequent or massive disturbance should be undertaken to accelerate habitat quality and ecosystem recovery.