At present, the main economic fish resources in the ocean are withering. However, because of its various disadvantages, the low-value trash fish causes insufficient fishing and processing. Therefore, it is necessary to study how to use low-value trash fish. 1. Animal protein feed: Due to the rapid development of aquaculture and special aquaculture in China, the demand for animal protein feed has increased rapidly. In 145th China's animal protein processing volume was 260,995 tons, and in 1996 it was 359,451 tons, with an average annual growth rate exceeding. 37%, to do so, China still imports about 350,000 tons of fishmeal every year. In the first half of 1999. The import of fishmeal reached 330,000 tons, accounting for 45% of the total imports of aquatic products. This shows that the demand for animal protein feed in China is relatively large, and there is still the possibility of further expansion. Animal protein feed has the advantages of high protein content, high animal meats, and easy combination with other ingredients, but China's fish meal production is generally low-grade, and its processing technology is backward, resulting in a low price of fishmeal and some high protein content fishmeal, such as The reliance on imports of shrimp powder and soft-shelled turtle powder is more serious. Surimi products: The surimi products have the same features as the animal protein feeds. The selection of raw materials depends on the type of fish, size, and structure of the fish. The fish of different sizes and sizes can be used together. Surimi products have a long history in China, but they have been dominated by manual operations. The number and types of surimi products in developed countries such as Japan and the United States are numerous, and the degree of industrialization is high. In Japan, there are between 2 and 3 million tons of fish used for processing surimi products every year. Its output accounts for the first place among various types of processed products. The types also evolved from fish cakes to simulated meat, shrimp, scallops, shark fin, and caviar products: The total amount of fish gills and their products in China was 49,813 tons in 1995, 82,364 tons in 1996, and 87,496 tons in 1997, with an average annual increase of more than 35.6%. The production process of surimi products and simulated seafood products is relatively simple. Generally, the original tuna fish is harvested, washed, rinsed, and processed. After gel, molding and other steps. Produce products that have similar appearance and taste to natural products: But for mass production it is necessary to solve a series of technical and equipment problems. At present, there are no clear research results on the study of the characteristics of different kinds of fish gills and how to prevent freezing damage in storage. There are even fewer special equipment and special production lines. Most of the equipment was imported from abroad, and the amount of starch used was generally higher for surimi products, which affected the taste. The market potential has not yet been fully explored. In the future, if the quality of the surimi is improved as the level of freezing continues to increase, and the flavor of surimi simulation products is improved, it is expected to further open up the international market and increase the utilization of low-value aquatic products. 3. Fish oil processing: Fish oil is rich in long-chain unsaturated fatty acids, especially docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). For the extraction of EPA and DHA, the general process is: raw fish → take the head → extract eye fat → boil extraction → oil separation → decolorization → deodorization → refined product. Research basically follows the foreign conclusions. 4. Casual snack foods: Such products are more prevalent in Japan, and our country sells less. Take dried fish as an example. The process is: raw fish→classification→washing→drying→flavoring→packing→finished products, the process looks simple, and the operation is quite difficult, because the mechanical strength of this type of fish itself is low, after drying It is fragile and easy to break. It is not easy to solve the problem of how to maintain the integrity of the fish body during processing, packing, transportation, sales, and storage. In addition. Such fish contain higher lipids in the body. How to ensure that they do not cause fat oxidation, browning and other problems during the baking process need to be studied. In addition to the above applications, low-value small sea fish are also used for the production of seasonings, fish decomposing proteins, and other products. However, no scale production was produced and the output was not large.