Donggang swimming crabs

Donggang swimming crabs

Donggang swimming crabs are a protected geographical indication product.

Donggang swimming crabs are a certified geographical indication trademark.

Donggang swimming crabs are an agricultural geographical indication product.

　　The swimming crabs in the waters of Donggang, Liaoning, are the Portunus trituberculatus species, commonly known as swimming crabs or white crabs. They belong to the class Malacostraca, order Decapoda, and family Portunidae. These crabs typically live and reproduce at depths of 3–5 meters, moving to deeper waters of 10–30 meters during winter and preferring to burrow in sandy or muddy seabeds. They thrive in salinity levels of 16‰–35‰, with a pH value between 7–9, an optimal salinity range of 26‰–32‰, and an ideal temperature range of 22°C–28°C. The water must be clean and highly oxygenated. When environmental conditions are unsuitable or molting fails, they may self-amputate their limbs, which can regenerate afterward.

　　The Portunus trituberculatus fishing season occurs twice a year, in spring and autumn, yielding high production volumes. These crabs are large, meaty, and rich in nutrition, especially their ovaries and liver. The ovaries can be used as premium seasonings. The meat is not only delicious when fresh but can also be canned and sold both domestically and internationally. Their shells can be used medicinally or to extract chitin, which has wide industrial applications.

　　Swimming crabs are at their strongest and most robust during the winter migration season, typically weighing around 250 grams, with some reaching over 500 grams. Female crabs are filled with rich red roe, offering exceptional flavor. These crabs can be eaten fresh, steamed, pan-fried, stir-fried, split in half and stewed with broad bean paste, or used in dishes such as crab stir-fried rice cakes, salted vegetables, or tofu — all common on the dining tables of coastal residents. They can also be preserved by curing: fresh swimming crabs are soaked in brine for several days until ready to eat, known locally as “fresh wind-cured crabs.” In the past, fishermen, due to the high yield of swimming crabs, would often select live crabs full of roe, extract the egg mass into bowls, and let it solidify by air-drying in the sun, creating “crab roe cakes” with unique and delicious flavors.

　　The swimming crabs grown in the Yellow Sea waters off Donggang have a longer growth cycle due to the cooler sea temperatures, resulting in exceptionally delicious meat. They are renowned both in China and abroad and have long been exported to countries such as Japan and South Korea. Since 2009, Donggang has exported more than 2,500 tons of swimming crabs, valued at 20.76 million US dollars.

　　Donggang swimming crabs

　　Geographic Scope

　　Donggang swimming crabs are mainly produced in the YaLuJiang River estuary fishing grounds and Yuanshan fishing grounds in the northern part of the Yellow Sea. The protected geographic area includes Zone 18, Zone 19, sub-zones 2, 3, and 6 of Zone 32, and Zone 33. The geographical coordinates span from 39°47′04″N, 123°30′57″E in the northwest to 39°00′00″N, 124°00′00″E in the southeast, with the northern boundary along the coastline, and the eastern and southern boundaries following the Chinese side of the China-North Korea maritime border. The total area is approximately 3,500 square kilometers.

　　Product Quality Characteristics

　　The unique marine hydrological, chemical, and biological conditions of the waters where Donggang swimming crabs live, along with the distinctive marine environment, contribute to the crabs’ exceptional quality. (1) External Characteristics: Donggang swimming crabs are large and plump in appearance, with clear body patterns, vibrant coloration, no black spots, and no gastric impressions above the navel. In terms of vitality, their claws are firmly attached to the body without looseness or sagging. Their gills are clear, white or slightly brown, with no foreign matter. Structurally, the crabs are well-rounded, with the abdomen tightly fitted to the central groove. When pressed, the abdomen feels firm, indicating dense, elastic meat that does not easily separate, and the crab roe is solid and non-flowing. For aroma, they emit the natural fresh and briny scent of live crabs, with no off-odors. (2) Internal Quality: The internal quality of Donggang swimming crabs features tender, snow-white meat, rich in protein, fat, and various minerals, offering the best flavor profile, with 52% edible content. Per 100g, the nutritional components include: aspartic acid (ASP) 956mg, threonine (THR) 433mg, serine (SER) 479mg, glutamic acid (GLU) 1435mg, glycine (GLY) 652mg, alanine (ALA) 570mg, cystine (CYS) 53mg, valine (VAL) 474mg, methionine (MET) 183mg, isoleucine (ILE) 366mg, leucine (LEU) 685mg, tyrosine (TYR) 360mg, phenylalanine (PHE) 463mg, lysine (LYS) 575mg, ammonia (NH3) 140mg, histidine (HIS) 182mg, arginine (ARG) 773mg, proline (PRO) 586mg, calcium 1.03mg, magnesium 825mg, zinc 32.9mg, eicosapentaenoic acid (EPA) 13.70% (of total fat), docosahexaenoic acid (DHA) 14.12% (of total fat), monounsaturated fatty acids 33.80% (of total fat), and polyunsaturated fatty acids 29.09% (of total fat). (3) Safety Requirements: In accordance with laws and regulations such as the "Fisheries Law of the People's Republic of China," "Product Quality Law of the People's Republic of China," "Agricultural Product Quality and Safety Law of the People's Republic of China," and "Food Safety Law of the People's Republic of China," as well as pollution-free agricultural product production standards, management of fishing grounds is strengthened. Standards strictly enforced include GB20556-2006 for Portunus trituberculatus, GB3097-1997 for seawater quality, GB11607-97 for fishery water quality, and NY5052-2001 for pollution-free seawater aquaculture water quality.