| 英文摘要 |
Sampling was conducted at 8 EPA sampling sites and additional selected sites in four seasons. Fish was the primary sampling organisms and riparian plants were also surveyed. In the middle and upper stream sites, the dominant species were Zacco pachycephalus, Acrossocheilus paradoxus, and Rhinogobius candidianu were sampled. The 2nd highway service road bridge had the highest number of average species, 9.3, and average number sampled, 211. The Shongtsu bridge had 6.3 number of species and 127.5 of individuials caught on average. The Tsuchi bridge had 5.8 number of species and 162.3 of individuials caught on average. The newchoshi bridge had 4.8 number of species and 47 of individuials caught on average. In the lower reach sites, the dominant species were Oreochromis sp., Liza macrolepis, and Hypsibarbus pierrei. The dongshi bridge had 7.5 of average number of species and 34.5 of fish caught. The Yueimeitan bridge had 3.8 of average number of species and 184 of fish caught. The Cheishow bridge had 5.3 of average number of species and 12.5 of fish caught. The Putzih bridge had 4.5 of average number of species and 10 of fish caught. The 2006 monitoring data have only data below the newchoshi bridge and number of fish caught. The dominant species were Oreochromis niloticus, Gambusia affinis, and Liza macrolepis. The newchoshi bridge had 1.8 number of species and 7.5 of individuials caught on average. The Yueimeitan bridge had 2.8 number of species and 49.8 of individuials caught on average. The Cheishow bridge had 3.5 number of species and 10.3 of individuials caught on average. The Putzih bridge had 4 number of species and 9.3 of individuials caught on average. In these four sites, the 2006 survey caught less number of fish and number of species than our project. In the dongshi bridge, the 2006 survey used different sampling mthod and had a higher number of fish caught, 61.8, but had less number of species caught, 4.3.
The developed Fish IBI, correlated with environmental gradients, can be used to assess human disturbance. The index of ecological integrity (IEI) was composed of Fish IBI, water quality, and habitat indices. Radar plots was used to exhibit IEI, which provided more complete information on each station. The results of analyzing water quality trend indicated that DO was elevating and BOD was decreasing.
The developed fish IBI, followed the protocol of US EPA, was correlated with environmental gradients and can be used to assess human disturbance. The fish IBI gave a satisfactory results after tested with data from different months. The index of ecological integrity (IEI) was composed of Fish IBI, water quality, and habitat indices. Radar plots was used to exhibit IEI, which provided more complete information on each station. The results of analyzing water quality trend indicated that DO was elevating and BOD was decreasing. Only limited fish data were available from past survey, which impeded comparison. Comparing with previous data, our results showed more numbesr of fish species for most sites, indicating a possible response to water quality improvement. Fish monitoring requires the same protocol for data comparison. Monitoring reports need to show tables of fish species and abundance for future analysis. We also derived indicator species with two statistical methods. For future development, this project suggests that developed index and indicator species need to be further tested within the ecoregion, indices of different group of taxa may improve our assessment of stream ecosystems, and evaluation of choices of proper indicators and fascilating recovery for stream restoration projects need to be understood.
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