| 초록 |
The objectives of this study were to determine the effects of stream nutrient regime, N:P ratios and suspended solids on fish tolerance/trophic compositions and stream ecosystem health, based on multi-metric model, during 2008-2013. Also, stream ecosystem health was evaluated in relation to chlorophyll-a (CHL) as a measure of algal productivity or indicators of trophic state to water chemical parameters. Total number of sampled fish species were 50 and showed a decreasing trend from 2008 to 2013. The minnow of Zacco platypus, based on the catch per unit effort (CPUE), was the most dominant species (25.9%) among the all species. Spatial heterogeneity was evident in the fish tolerance guilds that showed the dominance of sensitive species (89%) in the headwaters (S1) and the dominance of tolerant species (57%) in the urban. These conditions were directly influenced by concentrations of nutrients and organic matter (COD). The N:P ratios, as a barometer of water pollution, had a negative linear function (R 2 = 0.40, P 2 = 0.40, P m ) and insectivore sp. (I n ) on total nitrogen and total phosphorus, nitrogen had no significant influences (P gt; 0.05) to the two compositions, but phosphorus influenced directly the two guilds [slope (a) = -32.3, R 2 = 0.25, P n ; a = 40.7, R 2 = 0.19, P m ]. Such water chemistry and fish trophic guilds determined the stream ecosystem health, based on the multi-metric fish model. |
