Wiwan Hanamorn. Species diversity and distribution of mangrove gastropods in TBT contaminated areas at Chonburi province by GIS. Master's Degree(Environmental Biology). Mahidol University. : Mahidol University, 2008.
Species diversity and distribution of mangrove gastropods in TBT contaminated areas at Chonburi province by GIS
Abstract:
The objectives of this research were to study the species diversity and distribution of mangrove gastropods in three study areas - Samet, Laemchabung, and Chuksamet (Chonburi province). Also, gastropods and soils were analyzed for TBT concentrations by GC-MS. All data, such as species diversity and distribution of gastropods, soil structure, and TBT accumulation in gastropods and soil, were compared and reported using GIS. In all three study areas, only 21 epifauna gastropod species were found. Littorinidae and Ellobiidae were the most diverse families in this study. The diversity index and evenness were highest at Chuksamet and lowest at Samet. However, the highest similarity index was between Samet and Laemchabung. Assiminea brevicula, Melanoides tuberculata, and Clithon oualaniensis were the dominant species at Samet, Laemchabung, and Chuksamet, respectively. The distribution pattern was mostly clustered in all three study areas. Furthermore, the highest and lowest TBT accumulations in all tissue samples were found at Laemchabung and Samet, respectively (p<0.05). This study did not show the imposex in female snails even though TBT accumulations were found at low concentration. However, TBT accumulation in soil samples were the highest at Laemchabung (10.52±2.82 ng/g) and the lowest at Chuksamet (1.56±0.24 ng/g) (p<0.05). The Pearson Correlation demonstrated the relationship between physical factor values and TBT concentrations in soil and diversity index (p<0.05). This study showed the low TBT accumulation in the all gastropod tissues and soil samples at every study area. Thus, the findings of this study could be used as foundational information for future studies, and could also be used to encourage the protection of the mangrove environment