The Vietnam Fisheries Society issued a letter of protest against China's recent fishing ban in the East Sea to the Chinese embassy in Hanoi on Monday.
The opposition came less than a week after the Hainan province's Haikou municipal government issued a summer-long ban on areas that are under Vietnam's sovereign rule.
The Chinese ban went into effect on Monday and is set to continue until August 1.
The society also sent a letter to the central governement asking them to support local fishing communities.
Among the requests was a plea for officials to ensure that fishing teams are well-equipped with telecommunication devices so they can inform border guards when necessary.
Previously the Ministry of Foreign Affairs' spokesperson Nguyen Phuong Nga met with Chinese officials to voice opposition to the enforcement plan.