Beijing could struggle to enforce new fishing rules in the South China Sea because of difficulties in establishing a centralised coastguard.
Lin Yun, director of legal affairs for the Hainan Department of Ocean and Fisheries, said preparations to reform the coastguard were only half completed.
And the efforts are now running six months past the deadline set by Beijing - with progress still reported as slow.
Rules rolled out by the Hainan legislature, which took effect on January 1, require foreign fishing boats to obtain advance approval from the province before they can operate in the vast area of the sea claimed by China.
Xinhua reported that any foreign fishing vessel that enters the waters without permission will be expelled and have its catch confiscated, with fines of 500,000 yuan (HK$635,000).
The plan to integrate four sprawling maritime law enforcement entities into a unified coastguard were announced last March and state media reported that the coastguard went into operation in June.
But Lin said the efforts to make the coastguard more efficient and responsive have been held back by red tape. There were also competing interests among the bureaucracies responsible for patrolling the waters.
She said the China Marine Surveillance and the Fisheries Law Enforcement Command remained the mainstay of law enforcement fleets patrolling in the South China Sea because the coastguard system had yet to branch out to Hainan or any other provinces. "The merger [of the four law enforcement agencies] has not been smooth as this involves too many personnel and the restructuring of bureaucracies and their responsibilities," she said. "There is bound to be some opposition when you try to merge various agencies."
Lin also admitted that there was a lack of clarity on how Beijing defined "waters under Hainan's jurisdiction".
She said: "There has never been a clear border that lays out waters under Hainan's jurisdiction. The National People's Congress has never defined such a line, and the Hainan legislature does not have the right to do so."
When asked how law enforcers know the boundaries of their patrols, Lin said some of them might refer to the controversial "nine-dash line", which encompasses most of the South China Sea and reaches deep into waters claimed by other countries.
The US has criticised the new rules, with State Department spokeswoman Jen Psaki describing them as a "provocative and potentially dangerous act".
A report by the International Crisis Group in 2012 said Chinese law enforcement vessels risked causing international incidents in the absence of legal clarity on which waters should be considered under Beijing's jurisdiction.