Program
 
General Session 4: Marine environment, ecosystem & sustainability
 
 
 
Poster
Benthic dinoflagellate assemblages associated with Ciguatera Fish Poisoning (CFP) at fringing coral reef ecosystem of Perhentian Islands
GS4-18-S
Li Keat Lee* , Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaya, 16310 Bachok, Malaysia
Zhen Fei Lim, Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaya, 16310 Bachok, Malaysia
Hwa Lin Yong, Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaya, 16310 Bachok, Malaysia
Nurin I. Mustapa, Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaya, 16310 Bachok, Malaysia
Gires Usup, Faculty of Science and Technology, National University of Malaysia
Leo Lai Chan, State Key Laboratory of Marine Pollutions, City University of Hong Kong
Po Teen Lim, Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaya, 16310 Bachok, Malaysia
Chui Pin Leaw, Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaya, 16310 Bachok, Malaysia
Presenter Email: likeat92@gmail.com
Ciguatera fish poisoning (CFP) is a non-bacterial contamination of seafood by ciguatoxins (CTXs), a bioactive compound produce by benthic dinoflagellate Gambierdiscus. CTXs are known to assimilate and metabolized through multiple trophic levels of marine food web from herbivory fish to large predatory finfish. However, the influx of ciguatoxin into the marine food web remain ambiguous due to complexity in marine food web. As benthic dinoflagellates are known to be closely associated with benthic community such as seaweed, seagrass, turf algae and coral rubble. In order to trace the origin of the ciguatoxin flux, the distribution and natural assemblages of benthic dinoflagellate on different bottom substratum in coral reef ecosystem become the key element in the ciguatoxin flux. This study was aim to understand how the influx of ciguatoxin into the marine food web by looking at the distribution and natural assemblages of benthic dinoflagellate in different substratum. The study site chosen is Perhentian Islands, a coral-fringed islands off the coast of northeastern Malaysia in the state of Terengganu. A non-destructive approach for sampling was adopted by using artificial substrate. Photoquadrat was taken for habitat characterization using CoralNet, an online repository and source for benthic image analysis. 5 genus of benthic dinoflagellate, namely, Gambierdiscus, Ostreopsis, Coolia, Amphidinium, Prorocentrum were enumerated for distribution and assemblages. Fish and shell samples were collected for toxicity screening using mouse neuroblastoma assay (Neuro-2a). Light and temperature logger were used to record the changes along the sampling period. The preliminary result of distribution of benthic dinoflagellate according to depth show that Gambierdiscus, Ostreopsis and Amphidinium prefer shallow water (less than 10m) rather than deep water (10 to 25m) whereas Prorocentrum commonly found in both depth. Difference in depth also reflect in the light intensity as shallow water have light intensity range from 1670 ¦̀mol m-2 s-1 to 577 ¦̀mol m-2 s-1 whereas deeper water range from 563 ¦̀mol m-2 s-1 to 212 ¦̀mol m-2 s-1 . Temperature in water column across different depth range from 29 to 33 ¡ăC. Habitat characterization show that benthic dinoflagellate did have preference over bottom substratum range from sandy substrate to macrophyte coverage substrate. Gambierdiscus show preference to fine-filamentous algae (Lyngbya spp., Polysiphonia spp., Jania spp.) and coral rubble with turf algae with cell density range from 14 cells/100cm2 to 353 cells/100 cm2. While Ostreopsis are abundance in shallower and reef with high macrophytes coverage but rarely found in sandy substratum.