The industrial status, risks and countermeasures of seaweed farming in Shandong

China Aquatic Products Channel reported that nori farming has the characteristics of short production cycle, simple production operation, no consumption of feed, low production cost and high income, and has developed rapidly in suitable areas. In recent years, with the global warming, the seawater water temperature has increased year by year, the main production area of striped laver in Jiangsu coastal seaweed diseases are frequent, the success rate of breeding has decreased, and the benefits have declined, especially in the 2016-2017 breeding season, the production has been greatly reduced, and the loss is serious. Affected by this, some enterprises have successively sought to carry out seaweed culture in the southern waters of Shandong, and after the success of the previous trial breeding, the migratory culture of "southern vegetables and northern cultivation" of seabill has gradually become a new trend. From 2017 to 2018, the cultivation of seaweed in the south of Shandong has developed rapidly, and the scale of cultivation has reached about 200,000 mu (sea surface), forming a wave of seaweed farming boom. Through field investigation and investigation in Counties and Cities such as Rudong County, Dafeng District and Rizhao Lanshan District in Shandong Province, combined with the actual situation in Shandong Province, a brief analysis of the drawbacks of the development of seaweed farming in Shandong is now carried out, and a rough opinion on the scientific and standardized development of the seaweed breeding industry is put forward for the reference of producers and decision-making bodies.

The introduction of an industry is a huge project, it is necessary to consider whether the entire chain of the industry is smooth, and the lack of any link will lead to the collapse of the entire industry. Therefore, it is very necessary to have a comprehensive and in-depth understanding of all aspects of seaweed seedlings, breeding, processing, and sales.

Nursery session. The seaweed seedling stage is a filamentous body, hidden in the shell, and from May to September, the nursery pond is neatly lined with shells for seedlings. Under normal circumstances, the seedlings cultivated in a one-square-meter sea area can be cultivated in one acre of sea area.

Breeding links. The breeding cycle of seaweed is short, the effect is fast, and the production operation is relatively simple. The cost of sea surface aquaculture per mu is 2000 yuan - 3000 yuan, and the input is low, but there are problems of unstable yield, large price fluctuations and greater risk of disease. Seedlings begin to hang in late September every year, and seaweed is attached to the mesh curtain, which can grow when the tide is high, and dry the mesh curtain at low tide. From December to the end of April of the following year, 6 stubbles - 8 stubbles of seaweed can be harvested, about 3 acres of shallow sea waters can provide 1 mu of seaweed breeding area, and 1 mu of seaweed farming area can produce 1.5 tons - 3 tons of fresh seaweed per year.

One processing session. One processing should be done "three washes and two dry", "three washes", that is, the first time in the sea water to wash the sludge, and then rinse twice with fresh water. Wastewater does not contain pollutants, there is basically no risk of discharge pollution, Jiangsu processing plants are precipitated and discharged directly into the sea through pipelines (but affect the color of seawater). "Two dry", one is clean and remove impurities, the other is to use a dehydrator to dehydrate and dry, and finally form a tissue paper type of vegetable cake (3 grams / sheet), 1 ton of fresh seaweed can produce 0.1 tons of dried seaweed. The seaweed that has been processed once enters the seaweed trading market and is sold to secondary processing enterprises, and the primary processing of agricultural products is a primary processing of agricultural products and does not generate taxes.

Secondary processing and sales. Secondary processing is the seasoning and commercial packaging of primary processed seaweed. In the entire production process of seaweed, only secondary processing can bring tax revenue to local governments. The only countries in the world that cultivate striped seaweed are China, Japan and South Korea. Among them, China's annual output is about 5 billion pieces - 6 billion pieces, mainly exported to the European and American markets (mainly oem processing). Japan's annual output is 8 billion pieces, basically self-sufficient. South Korea's annual output of 10 billion pieces - 12 billion pieces, in addition to supplying the domestic market also exported to the European and American markets, due to the huge decline in China's production in 2016 - 2017, the price of seaweed soared, South Korean seaweed began to export to China.

Benefits and risks coexist, this is the eternal truth, behind the huge benefits of seaweed farming, what risks are hidden, according to the field investigation, combined with the actual situation in Shandong, the risk of shandong's development of the seaweed breeding industry can be summarized as "two restrictions, two influences, instability."

The sea area suitable for sea cultivation in Shandong is mainly a shallow sea area along the southern coast of Shandong, and the breeding method can be adopted by cutting rod culture and flap culture. Due to the waste of sea area, low yield, low survival rate of seedlings, and small waves in the sea area in winter that are easy to breed weeds, it is difficult to industrialize and promote large areas of flap culture. Shallow sea rod culture requires a water depth of 6 m - 12 m (climax), and most of the water area has been used by oysters, scallops and mussels as the traditional main breeding area, and there are fewer contiguous vacant seas that meet the conditions, and the large-scale development of seaweed culture is bound to have an impact on the traditional shellfish industry.

Since the seaweed needs to be processed within 24 hours after harvesting, it must be equipped with a processing plant near the land after large-scale breeding. The amount of fresh water required for each ton of fresh seaweed is about 30 tons per process, according to the development of 1 million mu (sea surface) of seaweed, the output of fresh vegetables is calculated according to 700,000 tons, and 21 million tons of fresh water is consumed during the processing period. In recent years, the supply of fresh water is often stretched, especially in the winter and spring seasons of one-time processing of seaweed, in addition to ensuring basic production and living water, it is difficult for most areas to provide a large amount of fresh water required for the processing of seaweed.

Proper cultivation of seaweed in a certain sea area is conducive to solving the problem of seawater eutrophication, increasing the dissolved oxygen of seawater, and thus improving the ecological environment of the sea area. When seaweed is cultivated on a large scale, in order to remove weeds, the curtains are sometimes soaked in hydrochloric acid or citric acid solutions, which pollute the seawater. Breeding rods (intertidal use of bamboo poles, shallow sea use of fiberglass tubes) and foam float after several years of aging, there is no recycling value, farmers may take the way of direct throwing into the sea, a huge amount of bamboo poles, foam floats drift with the current, FRP pipe will sink into the seabed, the sea bottom, marine ecology will cause damage. In June 2017, the Institute of Oceanography of the Chinese Academy of Sciences, together with the Ocean University of China, the First Institute of Oceanography of the State Oceanic Administration, the Beihai Branch of the State Oceanic Administration and other units, formed a systematic scientific understanding of the causes, prediction, early warning and development trend of the yellow sea moss green tide that appeared for 11 consecutive years, and released the latest research results, unanimously concluding that a large number of floating mosses are mainly from the shallow waters of northern Jiangsu, which is related to its unique environmental characteristics and a large number of local nori culture rafts. That is to say, the flooding of margin moss is closely related to the cultivation of seaweed in Jiangsu, and this ecological risk deserves the attention of every newly cultivated seaweed area.

The culture period of seaweed and the fattening and breeding period of oysters, scallops and other shellfish, the leading species traditionally cultivated along the coast of southern Shandong, basically overlap. In the case of limited basic productivity (nutrient salt), large-scale cultivation of seaweed is bound to compete with planktonic algae fed by shellfish for nutrient salts, affecting the reproduction and growth of shellfish basal bait, thereby affecting the fullness and meat quality of shellfish. At the same time, there are more hook shrimp (copepods) in this marine area, which will eat seaweed and affect the quality of seaweed, farmers may take the way of hanging or releasing insecticides for treatment, and farmers who take flap culture in deep water areas may use hydrochloric acid or citric acid to soak the net curtain to remove weeds, which will have a negative impact on the surrounding shellfish culture.

China's seaweed is mainly sold to the European and American markets, and mainly to processing, are to take order-based production, the annual demand for raw materials is basically determined, in the year when the output remains basically stable, the price of fresh vegetables 2 yuan / kg - 5 yuan / kg. From 2016 to 2017, due to the sharp reduction in production in the main producing areas of Jiangsu, the domestic gap reached 2 billion dried vegetable cakes (normal trading volume of 5 billion - 6 billion pieces), so the price of fresh vegetables soared to 8 yuan / kg - 12 yuan / kg, a record high. Stimulated by the soaring price, this year's non-main production areas of Jiangsu Lianyungang seaweed breeding scale rapidly developed to more than 300,000 mu, it is reported that Weihai Nanhai also developed to 100,000 mu this year, this kind of rushing up, blind expansion, it is very easy to cause overproduction, the formation of vicious competition, resulting in price instability, affecting the sustainable development of the industry.

The law of the market tells us that the development of a rush will inevitably raise tigers, so it is recommended to adopt a prudent attitude, explore the development of Shandong seaweed industry, and avoid blind large-scale new seaweed farming.

In view of the fact that the cultivation between small-scale seaweed and shellfish has a certain effect of improving the ecological environment in the sea area and isolating biological diseases, and the adverse effects can basically be solved through the improvement of breeding and processing technology and strict control of operation, it is recommended that 1-3 large-scale enterprises be selected to carry out pilot demonstrations and carry out small-scale harmless trial breeding. After the trial breeding has no adverse impact on the local leading industries and ecological environment, it is guided to establish a large-scale, scientific, standardized and ecological seaweed breeding model. Local governments and relevant functional departments shall, in conjunction with the zoning of marine functions and the issuance of aquaculture permits, carry out scientific planning and layout of suitable sea areas, reasonably demarcate the cultivation area, and punish illegal use of the sea.

As a nutritious and healthy food, seaweed is in short supply in the long run in a state of short supply for the market where consumer demand is expanding, so the realization of deep processing of raw materials is the only way for enterprises and industries to achieve development and improve efficiency. It is recommended that in the vicinity of the pilot, encourage and support interested enterprises to build supporting primary processing plants and secondary processing plants, or through vigorous investment attraction and inline external introduction, attract large food processing enterprises to "take root" here, realize the extension of the industrial chain, improve the added value of products, enhance market competitiveness, and create a new economic growth point of the marine industry without affecting the traditional leading industries to become bigger and stronger.

In recent years, with the occurrence of marine pollution incidents, marine protection has become a major event that many coastal local governments are concerned about and try to deal with, and environmental protection inspection has become an important factor that must be considered in local development and enterprise development. Therefore, before the introduction of seaweed culture, it is necessary to strengthen the monitoring of the local marine environment and the prevention and control of diseases, and provide relevant data and information for scientific and effective assessment of seaweed culture in the future. In the process of cultivating seaweed, it is necessary to pay attention to monitoring the source of environmental pollution in the breeding area, dynamically monitoring and analyzing the status of the aquaculture water body, and it is best to establish a marine pollution early warning system in the sea area where the seaweed is cultivated and produced. At the same time, nori processing enterprises should continuously improve the processing operation process of nori, implement HACCP system certification and ISO quality system certification, and ensure the safety of nori products from "water body to table".

Science and technology is the primary productive force, under the condition of limited external environment, science and technology will show a dazzling light, exert a strong endogenous driving force, and promote the leapfrog development of the industry. If an industry wants to achieve long-term stable and healthy sustainable development, it must be led by science and technology and vigorously promote the transformation of scientific and technological achievements into real productivity. Therefore, scientific research institutes should increase scientific and technological research and development efforts, develop seaweed seeds, ecological breeding technology models and advanced environmental protection breeding and processing facilities and equipment, break through regional and technical bottlenecks, and realize the transformation of new and old kinetic energy of the seaweed industry. At the same time, the government and relevant functional departments should actively carry out government services, strengthen the training of production skills and environmental awareness of seaweed employees, strengthen the standardization and standardized management of the entire industrial chain of seaweed, form a service system covering the entire industrial chain, and promote the standardized, healthy and sustainable development of the seaweed industry.

Author:Tan Lintao Xu Wenwen Zheng Fuqiang Wang Hangning Yu Chengsong Song Jianwei Wang Jinguo (Aquatic Technology Promotion Station, Rushan City, Shandong Province)