Hekou District, lying at longitude 118°08＇～119°05＇east and latitude 37°15＇～38°15＇ north, is located in the north of the Yellow River Estuary off the south shore of the Bohai Sea. It is accumulated by the mass of silt of Yellow River with a small gradient. It covers a large area with a coastline of 254.37 km long. The area within the -10m bathymetric line under sea is 3,500,000 mu. There are 970,000mu mudflat and 1,470,000 mu kaline soil. The sea water here is fertile with abundant bait lives. It has long been called “town of fishes” and “cradle of aquatic products” because of its large content of fish, shrimp, crab and shell.
  Along the coastline of Hekou, 195 species of tidal zone beings, among which 191 are animals (chart 2-14) accounting for 97.95% of the total, while the other 2.05% are alga including 4 species. The major animals are shell ones with mollusks at the second place. Shell animals are mainly Japanese Sentinel crab, three-tooth crab, the Whimbrel crab and macrophthalmus crab. Others are Japanese musk crab, Philyra pisum, Alpheidae, palaemon and Callianassidae. While mollusks include square clam, clam, scapharca subcrenata, cyclina sinensis Gmelin, razor clam, Jinjiang oyster and Guanghuahe clam. Others are dorsinia japonica, Tellinidae, Glaucomyidae and Bohai Laternula(E)marilina. The single shell animal is mainly spiral shell. Others are nassariidae, stenothyra and red snails.
  There about 20 species economic animals in the tidal zone and 0—-5m of the sublittoral zone. Most of them are shellfish, with the shell animals at the second place. They are scapharca subcrenata, cyclina sinensis Gmelin, razor clam, Jinjiang oyster, Guanghuahe clam, dorsinia japonica, Tellinidae, Glaucomyidae, Bohai Laternula(E)marilina, nassariidae, stenothyra and red snails. Shell animals are mainly Japanese Sentinel crab, three-tooth crab, the Whimbrel crab, macrophthalmus crab, Japanese musk crab, Philyra pisum, Alpheidae, palaemon and Callianassidae.
  Economic invertebrate: there are 59 species allocated in the coast of Hekou. Crustaceans are the most accounting about 42.4%. Among them prawn, Long-leg rough shrimp, blue crab, charybdis japonica and squill have been fished. Mollusks are the second most accounting for 35.6% including red snail and inkfish. 8.5% are echinoderms, while few are coelenterate and annelid.
  Fish: there are 85 species, 47 species accounting 55.3% of the total, are warm temperature ones, such as koro, raja porosa, scaled sardine, crucian carp and bass.
  1、Clam. It is called the “No.1 Tasty” because of its freshness and richness. It contains 10% protein, 1.2% fat, 2.5% carbohydrate and all kinds of amino acid, vitamins, calcium, potassium, magnesium, phosphorous and iron. The raising area of clam in China is now 250,000 mu with 2 brands, Jinhekou and Ruhaikou. The Ruhaikou brand clam won the prize of Famous Product in the China International Agriculture Expo in 2001. Both the two brands, 20,000mu breeding area, passed the nuisanceless produce certificate in 2005. their products are highly popular both at home and abroad. The major importing countries are Japan and Korea.
  2、Blue crab: Portunid is generally called crab, which is an absolute good taste among all the aquatic products. It is abundant in nutrition, including vitamin A, protein, fat, sugar, calcium, phosphorous and iron. It can also be used for medical purposes. It is very popular in clients and exported to Japan and Korea. At present, there are 40,000 mu raising area in Hekou. The crab passed the nuisanceless produce certificate in 2004. 60 tons were exported in 2005 by Haixing Company, earning USD1,200,000.
  3、Chinese prawn: With the large size, good flesh and thin shell, it is very popular in international market.
  4、Sea cucumber: It belongs to Echinodermata, Holothuroidea, containing profound protein, sugar without cholesterol. So it is favored by foreigners to make the supply insufficient. As a result, its price is always high. At present, China is the main importer of sea cucumber. In 1999 the putput was 2400 tons (dry weight), of which 2020 are cultivated. However, statistics show that there is a nearly 5000 tons’s demand in China, which means half of them will be imported. Now, the district is planning to construct a culture base covering 10000 mu in 3 years.
  5、South American prawn: It is now one of the breeds that have the highest output with eurysalinity. Its major advantages are long mating season, long survival time without water, short breeding cycle, high disease resistant, low demand of bait and big flesh content. At present, there are 40,000mu for its breeding, of which 25,000 mu is sea water, 15,000 mu is low salt water.