碩士 / 國立東華大學 / 海洋生物多樣性及演化研究所 / 97 / This study aims to understand the level of metal accumulation of fish otolith in the polluted river, and to discuss the relationships between otolith elemental composition and water chemistry. Two experiments are included in present study.
The first experiment was to collect fish and water samples in September to November 2007, from one of the most polluted river in southeastern Taiwan, Erren River, in order to understand the level of otolith metal accumulation in different species of fish and the relationship to water chemistry. All samples including otolith from six fish species and river water samples were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). One-way ANOVA indicated that otolith Mg, Fe and Ba to Ca ratios were not different among species, whereas the Na, Ni, Cu, Zn, Sr and Pb to Ca ratios were significant different among species. The highest Sr/Ca ratios were found in otoliths of Leiognathus splenden. Otolith Na, Ni, Cu, Zn and Pb to Ca ratios were higher in Elops machnata, Nematalosa come and Eleutheronema rhadinum than in Mugil cephalus, Terapon jarbua and Leiognathus splenden. Result of discriminant function analysis showed fish species with lower Sr/Ca ratios in otolith contains higher metal level. It indicated fish habitated in freshwater environments accumulate more meals in their otolith, and those species of fish can be used as better indicator on evaluation of the pollution accumulation.
The second laboratory experiment were designed to simulate different level of polluted environment by spiking different concentrations of lead, copper, zinc, manganese, strontium and barium in the rearing water, and to analyze the metal accumulation rate in fish otolith. Four experimental groups including low, median, and high spiking groups and one control group were designed and the estuary abundant and highly tolerant Mugil cephalus were chosen for study species. Barium and zinc concentration in rearing water did not show expected gradient, but other elemental concentration, including strontium, lead, copper and manganese showed significant gradient different among groups after spiking single elemental standard to the rearing water. The concentration of otolith Mn/Ca ratios formed during experiments is positively related to water Mn/Ca ratios, while other elemental ratios on otoliths were not related to the water chemistry. The results from laboratory rearing experiments showed the otolith chemistry did not completely reflect the changes in water chemistry. The mechanisms how metals in ambient precipitated on otolith may regulated by more complex physiological factors, and more studied are needed in the future.
| Identifer | oai:union.ndltd.org:TW/097NDHU5270012 |
| Date | January 2009 |
| Creators | Hong-You Hsu, 許弘佑 |
| Contributors | Chia-Hui Wang, Chih-Wei Chang, 王佳惠, 張至維 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 57 |
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