Effects of Typhoon Disturbance on the Abundances of Two Mid-Water Fish Species in a Mountain Stream of Northern Taiwan

Ling-Chuan Chuang, Bao-Sen Shieh, Chi-Chang Liu, Yao-Sung Lin, and Shih-Hsiung Lang (2008) Effects of typhoon disturbance on the abundances of two mid-water fish species in a mountain stream of northern Taiwan. Zoological Studies 47(5): 564-573. The objective of this study was to use a 9 yr dataset to evaluate the responses of Onychostoma barbatula and Candidia barbata abundances to 3 typhoon events in a mountain stream of northern Taiwan. The association of habitat variables with fish abundances was also explored. Bimonthly electrofishing was conducted at 4 sampling sites, and habitat variables of water depth and stream length were measured after each fish sampling. Few or no significant differences in fish abundances for each site were identified among bimonthly sampling periods and years. Abundance variations did not significantly differ before and after typhoon periods in the 9 yr dataset, in typhoon years, or in non-typhoon years. These results indicated that typhoon impacts on the abundances of these 2 mid-water fishes are minor despite the potential for habitat alteration in mountain streams of Taiwan. Mid-water fish in Taiwan may adapt to flow fluctuations in mountain stream by their good swimming performance, and by staying in or quickly dispersing to deeper regions as refuges. Based on the results of this study, typhoons invading Taiwan during the wet season should be cautiously regarded as a natural disturbance. However, floods caused by typhoons which occur in the dry season may still cause reproductive threats to aquatic organisms in Taiwan. Given that global warming may become more serious in the future, greater emphasis should be placed on determining drought impacts on stream organisms in Taiwan as there is currently a lack of academic information and in situ experience. http://zoolstud.sincica.edu.tw/Journals/47.5/564.pdf