54 million yellow clam seedlings released into the sea
Large-scale artificial farming of Dandong yellow clams has a promising future
"After 3 years of effort, this year we have bred Chinese clam seedlings with an average size of 5.4 mm, which will greatly increase the survival rate of the released stock." On August 10, Yuan Tian, chief of the Disease Prevention Section of the Dandong City Fisheries Technology Extension Station, who had just returned from the Donggang City Seedling Breeding Center, told reporters that a few days earlier they had successfully released more than 54 million newly bred juvenile Chinese clams into the waters off Dalu Island in Donggang. "Carrying out research on artificial breeding and intermediate rearing technology can provide large-sized seedlings for Chinese clam mudflat farming, shallow-sea bottom sowing enhancement, and stock enhancement releases, effectively increasing the resource volume."
The Chinese clam is commonly known as the "yellow clam." The waters adjacent to Dandong have shallow water, broad tidal flats, and a large tidal range. Influenced by runoff from the Yalu River and Dayang River, the offshore waters have active exchange, moderate seawater salinity, and abundant bait organisms, which make aquatic animals such as Dandong-produced yellow clams plump and tender. It is reported that in 2011, the Dandong yellow clam received geographical indication registration from the Ministry of Agriculture. At the end of 2015, after on-site assessment and review by an expert group from the Ministry of Agriculture, all indicators for the creation of the "Donggang large yellow clam" demonstration model passed acceptance.
It is understood that due to various factors, yellow clam production has decreased year by year. Each day, only more than 5,000 kg of yellow clams of catchable size can be harvested, a sharp decline of more than 90% in resource volume compared with more than ten years ago, making it urgent to carry out seedling propagation and resource restoration. "To explore artificial seedling technology for yellow clams, starting in 2012 our station launched research on artificial seedling technology for Chinese clams, aiming to solve the problem of seedling sources for artificial enhancement and farming and to provide technical reserves for future large-scale seedling production and the promotion of enhancement and farming," Yuan Tian said. In 2013 they bred 38.7 million juvenile clams, with an average shell length of 465.3 micrometers. In 2014 they bred 120 million juvenile clams, with an average shell length of 1.3 mm. This year they finally bred 54.12 million juvenile clams with an average shell length of 5.4 mm. In July this year, the project on artificial breeding and intermediate rearing technology for Chinese clams successfully passed scientific and technological achievement appraisal by the Dandong Science and Technology Bureau.
"Artificial stock enhancement and release plays an important role in economic growth and regional ecological balance. Artificially bred juvenile clams can be released once their shell length reaches more than 0.5 mm. The large-sized 5.4 mm seedlings released this year will greatly increase the survival rate of the release and will play a positive role in restoring local resources," Yuan Tian said. "The Dandong area has 130,000 mu of seawater ponds and 1.08 million mu of shallow sea. If pond farming is carried out in the future, about 24 billion juvenile clams will be needed each year, and if shallow-sea enhancement is carried out, the demand for seedlings will be even greater."