BEIJING, Feb. 26 (Xinhua) -- The China Coast Guard solved 91 human smuggling cases and participated in 349 maritime search and rescue missions in 2017, the coast guard said.

The coast guard also handled 891 smuggling cases involving a total of 4 billion yuan (about 631 million U.S. dollars) last year, including cases in refined oil, sugar, cigarettes, alcohol, frozen goods and rare wild animals.

About 3,000 fishing boats were fined for violations of fishing laws and regulations, such as fishing without license, using prohibited fishing tools and fishing in closed seasons. About 209 people faced criminal penalties.

The coast guard also spent a lot of resources cracking down on offenses compromising the maritime environment, investigating 702 cases last year.

The coast guard, which merged the maritime law enforcement functions of four agencies responsible for fishery administration, maritime surveillance, customs enforcement and border control, formally began operation in July 2013.