Qinzhou Oysters

Qinzhou Oysters

Qinzhou Oysters are a product with geographical indication.

　　 Oysters, scientifically known as Crassostrea rivularis, are one of the four precious seafoods in Qinzhou. Their meat can be eaten fresh or processed into oyster sauce or dried oysters. With over 40% protein content, the oyster meat is nutritious, delicious, and often referred to as the “milk of the sea.” It also has medicinal uses. Maowei Sea in Qinzhou Bay is the largest natural oyster spat breeding area in China, with superior spat quality unmatched by other sea areas. Qinzhou City is renowned as the “Hometown of Chinese Oysters.” Currently, the city has over 140,000 mu of intertidal and deepwater oyster farming areas, with more than 1.3 million mu of potential oyster farming tidal flats available for development.

　　Oysters, scientifically known as Crassostrea rivularis, are warm-water shellfish found in estuarine regions along China’s southeastern coast. Natural oysters typically attach to seabed rocks and grow to lengths of 15–20 cm, with some giants weighing up to 0.5 kg. The oyster shells are rough, thick, and either round or oval, with a grayish-black exterior and a smooth, white, glossy inner shell. The meat can be eaten fresh or processed into oyster sauce or oyster oil.

　　The Qinzhou Bay coastline stretches over 520 kilometers, featuring calm, deep waters that serve as a “natural pasture” for oyster farming. However, local villagers told reporters that not all sea areas are suitable for oyster spat cultivation. Maowei Sea, where the Qinzhou River meets the sea, is particularly well-suited for breeding oyster spat. Zhong Yuangxiang, a nearly 60-year-old village chief in Paibang Village, Jianzhen Town, Qinnan District, Qinzhou City, explained that the seawater salinity in Maowei Sea remains around 17 degrees, and the area features large mangrove wetlands nearby, providing ample food for oyster spat.

　　The Qinzhou coastal area is among China’s prime oyster-producing regions. According to data from the Qinzhou Municipal Aquatic Products Department, Qinzhou is a famous “Hometown of Oysters” in China. At present, there are over 140,000 mu of intertidal and deepwater oyster farming areas along the city's coast, mainly distributed in towns such as Longmen, Kangxiling, Dafanpo, Dongchang, and Jian Shan—especially Longmen. Maowei Sea in Qinzhou Bay is the largest natural oyster spat breeding area in China. Oysters are one of Qinzhou’s four precious seafoods (the other three being shrimp, blue crab, and grouper).

　　Qinzhou Oysters

　　Geographical Scope

　　The geographical protection area for the Qinzhou Oyster agricultural product geographical indication includes: the area from Maowei Sea to Qilong Port’s Seventy-Two Jing region, spanning from longitude 108°29'16.18" to 108°36'0.16" and latitude 21°40'54.09" to 21°52'7.96", covering a north-south width of 18.84 km, an east-west length of 12.27 km, and a total area of 111.7 square km. The surrounding areas include Qinzhou Port District, Jianzhen Town, Shabu Town, Dafanpo Town, Qilonggang Town, Kangxiling Town, and Fangcheng Maoling Town. The Dafengjiang area spans from longitude 108°50'2.36" to 108°53'16.12" and latitude 21°37'1.47" to 21°45'12.70", covering a north-south width of 6.13 km, an east-west length of 15.36 km, and a total area of 17.5 square km. The surrounding areas include Xiniujiao Town, Dongchang Town, Nali Town, and Hepu Xichang Town. The total protected area of both zones is 129.2 square km. The annual production of shell oysters is 150,000 tons.

　　Product Quality Characteristics

　　(1) External Sensory Characteristics: Mature oysters are large with diverse shapes, including round, oval, triangular, and rectangular forms. The shells measure 10–24 cm in length and 6–15 cm in height, and are thick and sturdy. The left and right shells are unequal, with the left shell being thicker, larger, and deeper, having fewer scales and attaching to other surfaces. The right shell is slightly flattened, with thin, flat, and smooth concentric scales on the surface. Younger oysters have fragile, thin, and flat scales, while older ones have densely stacked, stone-like, thick scales. The shell surfaces come in gray, green, purple, and brown-yellow hues. The ligament is long, broad, and purplish-black. The adductor muscle scar is large, generally oval or kidney-shaped, located on the central dorsal side. (2) Internal Quality: Oyster meat is plump, with a milky, shiny color, crisp and tender texture, delicious taste, and high nutritional value. Each 100 g of fresh meat contains ≥8.0g protein, ≤2.0g fat, ≥500.0mg calcium, ≥900.0mg zinc, and ≥62.5mg iron. Additionally, it is rich in vitamins, ash, and other substances. (3) Safety Requirements: During production, Crassostrea rivularis strictly adheres to relevant standards such as the Seawater Quality Standard (GB3097), Fisheries Water Quality Standard (GB11607), Pollution-Free Aquaculture Seawater Water Quality (NY5052-2001), and Pollution-Free Oyster Cultivation Technical Specifications (NY/T5154-2002). The final products meet the requirements of Pollution-Free Oysters (NY/T5155-2002).