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Authors requiring further information regarding Elsevier’s archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright Author's personal copy ecological indicators 8 (2008) 564–572 available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/ecolind Annual variations of biotic integrity in the upper Yangtze River using an adapted index of biotic integrity (IBI) Di Zhu a,b,c,1, Jianbo Chang a,b,c,* a Institute of Hydrobiology, Chinese Academy of Sciences, 7# Southern Road of East Lake, Wuhan, Hubei Province, 430072 China b Institute of Hydroecology, Ministry of Water Resources and Chinese Academy of Sciences, 578# Xiongchu Avenue, Wuhan, Hubei Province, 430079 China c The Graduate School of the Chinese Academy of Sciences, Beijing 100039 China article info abstract Article history: Adaptive modification and use of Karr’s index of biotic integrity (IBI) for the upper Yangtze Received 15 February 2007 River, including 12 metrics in five categories, have typically occurred in line with the data Received in revised form collected by 6-year commercial fisheries investigation. These investigations were under- 24 May 2007 taken annually in four sections of the Upper Yangtze main channel between 1997 and 2002. Accepted 19 July 2007 These four monitoring sections (Yibin – YB, Hejiang – HJ, Mudong – MD, and Yichang – YC) were selected because they represent the part of the river that will be covering a 1000 km stretch that includes the future Three Gorges Reservoir (TGR), upstream of the Three Gorges Keywords: Dam (TGD), an area influenced by the construction of TGD. In addition, historical data were Fish assemblages used to show changes in the watershed by comparison with field investigations recently. Index biotic integrity (IBI) The biotic integrity of the four sections were calculated and classified into different levels Three Gorges Dam (TGD) annually for recognizing its spatial and temporal variations. It was observed that IBI scores Upper Yangtze River were becoming lower diminishingly since 1997 in all the four sections. Because all the data were collected before the impoundment of the Three Gorges Reservoir, it is obvious that human activities, especially over-fishing, must be crucial factor instead of damming in the upper Yangtze River in that period. # 2008 Published by Elsevier Ltd. 1. Introduction Van Dolah et al., 1999). Fish assemblages were considered to be an appropriate end-point for assessing stream integrity due to The index of biological integrity (IBI) originally developed by their high public visibility, their position in the food chain and Karr (1981) and established by Karr et al. (1986) had previously high sensitivity to water quality (Karr, 1981; Karr et al., 1986). been used in the United States (Karr, 1999a; Karr et al., 1986; Human influences, such as changes in water chemistry or Karr, 1999b) and became increasingly adaptive elsewhere, e.g. physical habitat modifications, could alter fish assemblages by in Europe (Simon and Sanders, 1999). Many groups of disrupting their structures and functions (Fig. 1). Varieties in organisms had been used as indicators to estimate environ- fish assemblage could be detected through changes in mental quality. Algae, benthic invertebrates and fish were components of the community, functional groups, species typical species in biological monitoring (Matthews et al., 1982; diversity, and relative abundance (Wootton, 1990). The fish-IBI * Corresponding author at: Institute of Hydroecology, Ministry of Water Resources and Chinese Academy of Sciences, 578# Xiongchu Avenue, Wuhan, Hubei Province, 430079 China; Tel.: +86 27 8718 9023. E-mail address: [email protected] (J. Chang). 1 Main research fields: Ecology of Fishes and Conservation Biology, Aquatic Ecosystem Health Assessment. 1470-160X/$ – see front matter # 2008 Published by Elsevier Ltd. doi:10.1016/j.ecolind.2007.07.004 Author's personal copy ecological indicators 8 (2008) 564–572 565 Fig. 1 – Aftermath of river basin environmental structure changes. was commonly used and accepted worldwide as a reliable tool Dam was constructed in 1981 and has led to sharp declines in to assess water condition now (Novotny et al., 2005). The IBI the populations of migratory fish previously occurring in great had become a family of multi-metric indices that were numbers in the upper Yangtze River, especially the three regionally adapted and calibrated, because rivers of different endemic ancient fish species, Chinese sturgeon (Acipenser regions, as well as their fish communities, were distinctive sinensis), River sturgeon (A. dabryanus), and Chinese paddlefish (Kesminas and Virbickas, 2000). (Psephurus gladius)(Dudgeon, 2000; Xie, 2003; Young, 2003). The Despite many outstanding works on IBI had already been Three Gorges Dam (TGD) (38 km upstream from the TGD) is done (Novotny et al., 2005; Simon et al., 2000), it was still of going to a massive human intervention which will fragment utmost importance for us to continue this work in Chinese an area of about 58,000 km2 with the formation of a reservoir Yangtze River basin. The objectives of this study were to: (a) of 1080 km2 in an area of the former Yangtze River bed. develop potential metrics of fish indicator for the upper This study reach of the river is influenced by TGD and is Yangtze River; (b) quantify fish assemblage differences in the 1040 km long, including the main channel of the upper early 6 years of Three Gorges Dam (TGD) construction; and (c) Yangtze River. Four monitoring stations were set up at provide a baseline for future water quality assessment in the different reaches, from the upper to the lower reach. These upper Yangtze River. were at Yibing (YB), Hejiang (HJ), Mudong (MD) and Yichang (YC), respectively (Fig. 2). The Yibin (YB) station was located in Yibin county, covering a monitoring stretch of 21 km, 2. Materials and methods including the lower reach of the Jinsha River. The Mudong (MD) station was located in Mudong town in a distance of 2.1. Study area 50 km from ChongQin City. The station represented a location at the deepest part of the TGD Reservoir. The monitoring reach The River is the third longest river in the world; its total length covered a stretch of 30 km. The Hejiang (HJ) station was is about 6300 km with a basin area of about 180,000 km2. The located in Hejiang county of the Sichuan Province with a river is distinctive in its species diversity and abundance, monitoring stretch of 60 km. Finally, the Yichang (YC) station while comprising the largest components of the fish resources was located in Yichang City, with a monitoring reach of 25 km in China (Chang, 1999; Wu, 2003; Young, 2003). However, the from Gezhouba Dam to Gulaobei. Yangtze River has experienced major changes over the past decades (Chang, 1999). Most of the water resources are 2.2. Data collection methods and analyses disproportionately degraded by human activities such as water pollution, agricultural land use and irrigation farming, Fishery investigations had been conducted in Yangtze River dam construction and over-fishing (Chang, 1995; Young, 2003). from 1950s till 2002 covering different reaches, together with These man-made impacts are now of highest concern with the field investigations, these data provided very important regard to the disruption of the integrity of Chinese inland baseline information, which were of tremendous value for waters (J.B. Chang, 1999; Chang, 1999). River damming is the assessment of ecological effects of human activities. The most dramatic anthropogenic factor affecting freshwater biological data (1997–2002) were obtained from the TGD environments (Baxter, 1997; Dudgeon, 2000). The Gezhouba monitoring database of the Institute of Hydrobiology (IHB), Author's personal copy 566 ecological indicators 8 (2008) 564–572 Fig. 2 – Study areas selected in the upper Yangtze River and distribution of four monitoring stations: Yibing (YB), Hejiang (HJ), Mudong (MD) and Yichang (YC). (TGD represent the location of Three Gorges Dam and GZD represent the location of Gezhouba Dam). Chinese Academy of Sciences (CAS). Most of the data were represent the best physical, chemical, and biological condi- obtained by field investigations and others were derived from tions. We modified the index and developed biological literatures. Twice investigations were conducted in May–July expectation for the upper Yangtze River fish assemblages. and September–December from 1997 to 2002 at the four These expectations were developed with the assumption that monitoring stations. The duration of investigation was 20 days ‘‘least impact’’ conditions would emerge from the cumulative every time. The catches were collected from fishing boats and data set. fish markets, the commercial fishing boats were sampled Yangtze Rivers has been dammed, channeled and dredged. according to the principle of random sampling at each station. Also, it is home to large urban areas and numerous point