Changes in density and diversity of fish resources before and after the tsunami in Kedah waters using a commercial trawler
2005
Abdul Haris Hilmi Ahmad Arshad | Abu Talib Ahmad | Halimah Mohamed | Ahmad Adnan Nuruddin
This study compares results between surveys conducted in February and May 2005 i.e., about two and five months after the tsunami, with results from a survey conducted in February 2004 in the coastal waters of Kedah. All these surveys were carried out using a hired wooden commercial Zone B trawler of 29.9 GRT. Observations were made on the changes in term of density and diversity in the catches obtained from the tsunami affected area. Subsequently, observations on these changes were analyzed by re-grouping the compositions of catches into environmental groups and trophic level groups in order to see if the tsunami affected any particular group of fish. Results showed a sharp increase in density and diversity of fish, particularly demersal fish, demersal invertebrates and pelagic invertebrates. The demersal fish composition in the total catch in 2005 was 62%, compared to only 41% in 2004. Statistical analysis showed that the densities in February 2005 were significantly different (P less than 0.05) from the densities in February 2004 and May 2005, There was no significant difference between densities of fish before tsunami and five months after that tsunami. The changes increased the mean trophic level from 3.46 (omnivores, herbivores and detritivores) before the tsunami to 3.69 and 3.68 (mid-level carnivores) after the tsunami.
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