The impacts of invasive Nile tilapia (Oreochromis niloticus) on the fisheries in the main rivers of Guangdong Province, China

• The increase of Nile tilapia has caused the decrease of CPUE in the main rivers.
• The presence of Nile tilapia influenced the growth of native mud carp.
• The increase of Nile tilapia in rivers has reduced the income of fishermen.
• The increase of Nile tilapia will increase the fishing pressure on native species.

Nile tilapia (Oreochromis niloticus) is one of the most widespread invasive fish species, and this species has successfully established populations in the major rivers of Guangdong Province, China. Field surveys and manipulative experiments were conducted to assess the impacts of Nile tilapia on fisheries. We determined that the increase of Nile tilapia in these rivers not only affects the CPUE (catch-per-unit-per-effort) of the fish community and native fish species but also reduces the income of fishermen. In the manipulative experiments, we observed that the growth of native mud carp decreased in the presence of Nile tilapia. Our results suggest that the invasion of Nile tilapia negatively affected the fishery economy and native fish species, and suitable control measurements should be taken.