Evaluating short-term disturbance effect to freshwater fish diversity based on South Korea's environmental impact assessment

Background/Question/Methods

Many countries recognize the importance of biodiversity and the policy to sustain the biodiversity of current day. Taxonomic diversity was and is used to evaluate the degree of diversity, however trait based functional diversity has been proposed to improve the shortcomings of taxonomic diversity.South Korea is home to many temperate and few tropical fish species, however these habitats are undergoing a drastic change due to many urban and non-urban development near the streams and rivers. Their effect to freshwater fish diversity must be more accurately evaluated.We calculated and evaluated 4 taxonomic diversity metrics and 4 functional diversity metrics(functional richness, functional evenness, functional divergence and Rao’s quadratic entropy), and to do so we organized 6 trait groups(environment/milieu, climate zone, vertical position, migratory behavior, feed type and length) retrieved from FishBase(www.fishbase.org); a database of fish species’ traits.We tried to evaluate the short-term effect of these disturbance with data based on the environmental impact assessment of South Korea. EIA reports that satisfies three criteria was selected for review. EIA reports and post-EIA reports were reviewed to check species and their abundance. We then performed a correlation analysis to see whether the metrics share similar increasing or decreasing pattern.

Results/Conclusions

High correlation was found between taxonomic diversity metrics, which means that 4 taxonomic diversity metrics share similar results and show similar patterns of diversity. Functional richness and functional divergence showed fairly high correlation with taxonomic diversity metrics, but functional evenness and Rao’s quadratic entropy showed little correlation with other metrics.Many researches focus on the long-term effect of disturbance to diversity changes, however we tried to focus on the short-term changes. The results imply that the current environmental impact assessment, which only evaluates taxonomic diversity, is giving insufficient understanding of environment's reaction to the disturbances. This can be improved with the application of functional diversity and their metrics. The evaluation of diverse metrics should be the basis for detecting environmental changes caused by development and establishing future conservation plans.Quantitative evaluation and further understanding of functional diversity metrics is an important challenge. This research can be further improved with multiple research topics; 1) a limited analysis to a specific basin 2) organizing different traits matrices matching new research interests 2) comparison with other countries’ environmental impact assessment and their results.