Fish invasion in the river systems of Guangdong Province, South China: Possible indicators of their success

Abstract

Although a large number of fish species have been introduced into Guangdong Province in Southern China, a few species, such as tilapia (Tilapia spp.), North African catfish Clarias gariepinus Burchell, mrigal carp, Cirrhinus mrigala (Bloch) and the sucker mouth catfish (Hypostomus sp.), have established natural populations and can be considered “successful invaders” in large rivers. The specific mechanisms underlying these contrasting results among different introduced fish species remain understudied. The relationship between multiple abiotic–biotic factors and the success of four invasive species was investigated using survey data for the Guangdong Province river ecosystem. In contrast to previous studies that have considered species‐specific traits, the focus was on economic, ecological and anthropogenic factors to predict invasion success. Four main predictive indicators were found: (1) successful invaders were of low or no commercial value; (2) successful invaders tolerated a wide range of environmental conditions, including poor water quality; (3) biodiversity loss accelerated the growth of non‐native populations; (4) human disturbance facilitated population growth and spread of invasive fish species. To lessen the impacts of invasive fish species, the selection of breeding species and breeding areas, maintenance of water quality and reduction in water pollution, protection of the diversity of fish species and reduction of human interference should be addressed.

Tilapia fisheries in Guangdong Province, China: Socio‐economic benefits, and threats on native ecosystems and economics

“…Tilapias are prolific invaders (Arthur et al., ; Canonico et al., ; Hu, ). In the rivers of south China, tilapia have become the most common alien fish species, with wild populations established in Hainan, Guangdong, Guangxi, Fujian and Yunnan provinces (Figure ) (Chen, ; Deng, Zhang, Zhao, Zhou & Zhang, ; Fang, ; Gu, Mu, Luo, Li, Wang, et al., ; Gu, Mu, Luo, Li, Yang, et al., ; Gu, Hu, et al., ; Gu, Yu, et al., ; Hu, ; Tan, Li, Li & Li, ; Yu et al., ). Tilapia overwinter and have established self‐sustaining populations in rivers of these provinces (Chen, ; Gu, Hu, et al., ; Gu, Yu, et al., ; Hu, ; Tan et al., ).…”

“…Their dispersal potential and environmental adaptability is considerable. Populations have grown rapidly, and their distributions in natural waters have expanded quickly in recent years through natural dispersal (Gu, Hu, et al., ; Hu, ).…”

“…The increase of tilapia in rivers of Guangdong Province has affected the incomes of fishermen in freshwater capture fisheries Gu et al., ; Gu, Hu, et al., ; Gu, Yu, et al., ). As the proportion of tilapia increases in fisheries, catch‐per‐unit‐effort (CPUE) decreases (Gu et al., , ).…”

“…Although a large number of fish species have been cultured, only a small number of species have been introduced widely beyond their native range, and fewer species have become global invasive species, including common carp, Cyprinus carpio L.; tilapia, Oreochromis spp. ; and rainbow trout, Oncorhynchus mykiss (Walbaum) (Table ) (Arthur et al., ; Gu, Hu, et al., ; Ottinger et al., ). Tilapia have been introduced to over 90 countries worldwide with a global distribution second only to common carp (Figure ) (Altun, Tekelioglu & Danabaş, ; Arthur et al., ; Attayde, Brasil & Menescal, ; Canonico, Arthington, McCrary & Thieme, ; Cassemiro, Bailly, Graca & Agostinho, ; De Silva, Subasinghe, Bartley & Lowther, ; Grammer, Slack, Peterson & Dugo, ; Gu, Mu, Luo, Li, Yang, et al., ; Lusk, Luskova & Hanel, ; Mert & Cicek, ; Ottinger et al., ; Peterson, Slack & Woodley, ; Rajabipour, Mashaii, Sarsangi, Mohammadi & Matinfar, ; Russell, Thuesen & Thomson, ; Thodesen et al., ; Wu & Yang, ).…”

“…As the largest tilapia producer in China, Guangdong Province produces almost 40% of the country's total production (China Fishery Yearbook 1990 ‐ ). Although the cultivation of tilapia in Guangdong Province has brought enormous economic benefit, tilapia have become the most common fish species in the rivers of Guangdong Province and can be considered successful invaders (Gu, Hu, et al., ). Consequently, Guangdong Province can be considered a typical area to study the socio‐economic benefits and damage caused by tilapia.…”