| Summary: | 碩士 === 國立中山大學 === 海洋資源學系研究所 === 89 === Abstract
The aim of this study investigated the metal bioaccumulation in the cetaceans from the Taiwanese coastal waters. The differences of metal concentrations in the small dolphins between species, sex and sampling location were examined. The results were compared to the data all over the world to understand the pollution status in the western Pacific. Accordingly specimens-bank was established. Furthermore, the correlations between the size/age and metal concentrations were investigated in Stenella attenuata, S. longirostris and Neophocaena phocaenoides.
This study cooperated with the Cetacean Research Laboratory leading by the Prof. L. S. Chou, Dept. of Zoology, National Taiwan University. The samples included 8 species of 83 individuals accidentally caught and stranded around Taiwan in 1994-1995. The 8 species included Delphinus delphin, Grampus grieus, Lagenodelphis hoseei, Stenella attenuata, S. coeruleoalba, S. longirostris, Steno bredanensis, Tursiops truncatus. In addition, one Kogia simus stranded in 1998 and two Neophocaena phocaenoides accidentaly caught in 2000 were used to examine the variation of metal bioaccumulation in the muscles at different parts of body. The tissues of muscle, liver and lung were used for analysis of Ag, As, Cd , Co, Cu, Fe, total Hg, organic Hg, Mn, Ni, Se and Zn. The flame atomic absorption spectrophotometry (AAS) was used in analysis of Cu, Fe, Mn, Ni and Zn. The cold vapor AAS and graphite furnace AAS were used for determination of Hg and Cd, respectively. ICP-MASS were used in measurements of Ag, As, Co and Se.
The differences of metal bioaccumulation in muscles of different species were element ally depend. As, Fe, total Hg, organic Hg, Se and Zn presented significant species differences. Highest Fe (147 mg/Kg wet wt), total Hg (16.9), organic Hg (5.65), and Se (4.62) were found in Lagenodelpnis hosei, whereas highest As (2.92) and Zn (24.1) were found in Grampus griseus and Tursiops truncatus. However, lowest As (0.29), and Se (0.76) were found in Tursiops truncatus. Lowest Fe (90), organic Hg (0.93), total Hg (1.0) and Zn (10.16) were found in Delphinus delphis, Delphinus delphis, Steno bredanensis, and Stenella longirostris. No species differences were found in the muscle concentrations of Ag, Cu, Cd, Co, Mn and Ni. Except organic Hg found highest in muscle. The concentrations of rest elements were found highest in liver and lowest in muscle. There was no significant difference of metal bioaccumulation found in male and female Stenella attenuata.
The correlations between the size/age and metal concentrations in muscle were found in Stenella attenuata, S. longirostris and Neophocaena phocaenoides. The relationships were significant in total Hg, oranic Hg and Se of Stenella attenuata, whereas in orangic Hg, Se and Zn of Stenella longirostris and Neophocaena phocaenoides.
The metal concentrations found in this study were mostly equal to or lower than those records all over the world. Furthermore, by comparison the total Hg of Stenella attenuata, S. coeruleoalba and Tursiops truncatus with those data found in elsewhere. The total Hg levels in this study were slightly higher than that of eastern Pacific, but much lower than that of Mediterranean of Italy and France, Atlantic and Japan. These findings suggest that the metal concentrations found in this study representing the baseline metal concentration of western Pacific. Based on this, no specific sight of pollution was found in the coastal waters off Taiwan.
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