Fishermen unload the last catch of the season in Qionghai, Hainan province, on Monday. The fishing season in the South China Sea ended at noon on Monday.[Photo by Luo Yunfei/China News Service]

An annual fishing ban was introduced nationwide on Monday, weeks earlier than previous years for some regions, with the aim of better protecting fisheries and the environment.

In the past, the off-season began on a staggered schedule - different days for different areas - with a June 1 deadline. It was moved up mainly because the spawning season of most fish has begun earlier, owing to the decay of fishery resources and global warming, said Zhang Xianliang, director of the Ministry of Agriculture's Bureau of Fisheries.