Status and historical changes in the fish community in Erhai Lake

Abstract

Erhai Lake is the second largest freshwater lake on the Yunnan Plateau, Southwest China. In recent decades, a number of exotic fi sh species have been introduced into the lake and the fi sh community has changed considerably. We evaluated the status of the fi sh community based on surveys with multimesh gillnet, trap net, and benthic fyke-net between May 2009 and April 2012. In addition, we evaluated the change in the community using historical data describing the fi sh community and fi shery harvest. The current fi sh community is dominated by small-sized fi shes, including Pseudorasbora parva , Rhinogobius giurinus , Micropercops swinhonis , Hemiculter leucisculus , and Rhinogobius cliffordpopei . These accounted for 87.7% of the 22 546 total specimens collected. Omnivorous and carnivorous species dominated the community. A canonical correspondence analysis (CCA) plot revealed that the distribution of fi shes in the lake is infl uenced by aquatic plants, water temperature, pH, and season. The abundance of indigenous species has declined sharply, and a majority of endemic species have been extirpated from the lake (a decrease from seven to two species). In contrast, the number of exotic species has increased since the 1960s to a total of 22 at present. The fi shery harvest decreased initially following the 1960s, but has since increased due to the introduction of non-native fi sh and stocking of native fi sh. The fi shery harvest was signifi cantly correlated with total nitrogen, not total phosphorus, during the past 20 years. Based on our results, we discuss recommendations for the restoration and conservation of the fi sh resources in Erhai Lake.

Measuring ecosystem degradation through half a century of fish species introductions and extirpations in a large isolated lake

“…The others exotic fishes were introduced as fellow travelers, such as the topmouth gudgeon (Pseudorasbora parva), and gobies (Rhinogobius giurinus, and Rhinogobius cliffordpopei) (Du and Li, 2001;He et al, 2010;Wu and Wang, 1999). Following the establishment of those non-native species and the concomitant decline or extirpation of native species over the past 50 years, the main harvest species of Lake Erhai shifted from the middle-sized native fishes (Schizothorax taliensis, Cyprinus chilia, and Cyprinus megalophthalmus) to the small-sized exotic fishes (P. parva, R. giurinus, and R. cliffordpopei) (Du and Li, 2001;Tang et al, 2013;Wu and Wang, 1999). Currently, 11 out of the 17 native fish species are included in the China Red List of Threatened Species, with 6 listed as critically endangered.…”

Age, growth and population dynamics of two congeneric and invasive gobies, Rhinogobius giurinus and R. cliffordpopei (Actinopterygii, Gobiidae) in a plateau lake, southwestern China

“…The dominant fish in the lake are small-bodied and non-native species, including freshwater gobies (R. giurinus and R. cliffordpopei), Neosalanx taihuensis (Chen, 1956), Pseudorasbora parva (Temminck & Schlegel, 1846), Hypseleotris swinhonis (Günther, 1873) and Hemiculter leucisculus (Basilewsky, 1855) (Guo et al, 2012;Tang et al, 2013). Channa argus (Cantor, 1842) is the only recorded piscivorous fish species and it is a rare species in the lake .…”

“…the middle and lower reaches of the Yangtze River, Wu & Zhong, 2008) and have been inadvertently introduced into several lakes in Yunnan-Guizhou Plateau (southwest of China) in the 1950-60s (Du & Li, 2001;Xie et al, 2001). The two species have then spread to most water bodies across Yunnan-Guizhou Plateau and become dominant in many lakes (Yuan et al, 2010;Tang et al, 2013). Invasive fish species are considered as one of the major causes of the local decline and/or extirpation of native fish (Du & Li, 2001;Xie et al, 2001;Yuan et al, 2010) and local control actions have been implemented.…”

“…Invasive fish species are considered as one of the major causes of the local decline and/or extirpation of native fish (Du & Li, 2001;Xie et al, 2001;Yuan et al, 2010) and local control actions have been implemented. However, they have limited success (Du & Li, 2001;Yuan et al, 2010;Tang et al, 2013), probably because of a knowledge gap in the biology of the two targeted species.…”

Assessing fish distribution and threats to fish biodiversity in the Yangtze River Basin, China

“…Invasion by exotic species is a serious threat to fish biodiversity in some plateau lakes of the upper Yangtze River, such as Lake Dianchi and Lake Erhai Tang et al 2013). Since the late 1950s, Chinese family carps (i.e., silver carp Hypophthalmichthys molitrix, bighead carp Aristichthys nobilis, grass carp Ctenopharyngodon idellus, and black carp Mylopharyngodon piceus), the Taihu icefish Salangichthys tangkahkeii, and other exotic commercial fishes have been introduced from the middle and lower reaches of the Yangtze River Basin to enhance fishery production in the plateau lakes.…”