2024-03-28T09:09:44Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1732632018-12-15T01:55:44Zcom_10261_88com_10261_8col_10261_341
00925njm 22002777a 4500
dc
Jo, Hyunbin
author
Jeppesen, Erik
author
Ventura, Marc
author
Buchaca, Teresa
author
Gim, Jeong-Soo
author
Yoon, Ju-Duk
author
Kim, Dong-Hwan
author
Joo, Gea-Jae
author
2018
Worldwide, increasing amounts of dams and weirs have been established in rivers in recent decades, often with drastic effects on their ecosystems. Between late 2009 and 2011, 16 large-scale dams were built in the main channels of the four largest rivers in South Korea, eight of these along the main channel of Nakdong River (300 km, 520 km in total). We studied the effect of these constructions on the fish community in the riparian zone based on intensive fish field surveys conducted in the littoral zone during 2007–2017, analysis of fishermen's catch data and molecular analysis of the diet of the keystone species, largemouth bass (Micropterus salmoides). Our results, based on RDA and GLM analyses, showed that environmental characteristics and fish species composition changed significantly with dam construction. Total fish abundance and biomass decreased after the start of the weir construction and fish richness decreased with time. The abundance and biomass of exotic fish decreased during construction but recovered afterwards, leading to higher proportions of exotics. Dominance and Shannon indices did not change significantly from before to after construction, while the Evenness index showed a significant decreasing trend. A comparison of the diet composition of largemouth bass showed decreasing genetic variation after construction. The changes in Functional Feeding Group (FFG) of the benthic communities at the study sites did not coincide with FFG changes in the prey items of largemouth bass, indicating a transition in feeding mode from before to after construction. In conclusion, the endemic and native fish species were most sensitive and showed lower resilience to disturbance by the large-scale dam construction than the translocated and exotic species, and the lake-like ecosystems after construction markedly improved the competitive capacity of these exotic fish over the native and endemic species in the riparian zone of the river.
Science of the Total Environment : doi:10.1016/j.scitotenv.2018.11.446 (2018)
0048-9697
http://hdl.handle.net/10261/173263
Genetic variability
GLM analysis
RDA analysis
Fish species composition
Functional feeding group
Resilience
Riparian zone
Responses of fish assemblage structure to large-scale weir construction in riverine ecosystems