Mariculture is a production activity that uses shallow coastal beaches to breed marine aquatic economic animals and plants. Including shallow sea farming, tidal flat farming, harbor farming, etc. The main objects of mariculture are fish, shrimps and crabs, shellfish, algae, sea cucumbers, and other economic animals. It is an important part of the aquaculture industry.
1. According to the breeding objects
It can be divided into fish, shrimps, crabs, shellfish, algae, sea treasures, etc., shellfish and algae are the most common, followed by shrimp;
2. According to the degree of intensification
It can be divided into the extensive culture, semi-intensive culture, and intensive culture;
3. According to the production method
It can be divided into monoculture, polyculture (such as fish and shrimp), and intercultural (kelp and mussel).
Aquaculture is the water available for cultivation (including planting) used by humans. According to the ecological habits of the aquaculture objects and the different requirements for the environmental conditions of the waters, it uses aquaculture technology and facilities to engage in aquatic economic animal and plant breeding and is an agricultural production department. one. According to the nature of the water area, it is divided into marine aquaculture and freshwater aquaculture. Therefore, mariculture is a branch of aquaculture. The scope of mariculture is smaller than that of aquaculture. The objects of aquaculture include fish, shrimps and crabs, shellfish, and algae, gorgon, lotus, lotus root, etc., while the objects of mariculture are mainly fish, shrimps and crabs, and shellfish. , Algae and sea cucumbers and other economic animals.
(1) Use seawater to enclose ponds, tidal flats, harbors, and offshore to grow fish, shrimp, crabs, shellfish (including pearls), algae, sea cucumbers, and other marine economic animals and plants;
(2) The seawater nursery breeds and protects seedlings of various seawater animals and plants;
(3) Breeding of offshore pastures (such as release, transplantation, artificial reefs, bubble curtain or micro-current purse seine culture, large-scale anti-wind and wave cage culture, etc.);
(4) Protection and breeding of high-quality seed genes, pest control, environmental pollution, nutrient feed research, breeding facilities transformation, and computer automatic breeding control technology.
The advantage of mariculture is to focus on the development of certain fish, shrimp, shellfish, and echinoderms (such as sea cucumbers) with higher economic value, with a shorter production cycle and higher yield per unit area. However, most of the world's marine aquaculture systems have entered semi-intensive or intensive aquaculture, and the feeding of bait and the generation of residual bait are an important factor that contributes to the pollution of aquaculture itself. Specifically, the pollution of shrimp farming mainly comes from the N and P nutrients dissolved out of the new residual bait, and the large amounts of sulfide, NH4, and suspended solids in the cultured seawater. In addition to the residual bait, fish also include fish feces and Its excrement, the nutrients contained in these substances, namely N, P, and organic matter, will have a eutrophication effect on the water body and the bottom mud. Generally speaking, the pollution of breeding itself is organic pollution, and its form is mainly to increase an environmental load of N and P.
Driven by economic interests, many areas have developed aquaculture in a disorderly, indiscreet, or even gratuitous way. Large-scale reclamation has reduced the sea area and the amount of tidal absorption weakened the self-purification capacity of the ocean and aggravated the deterioration of the water environment. Breeding owners blindly build cages on the sea and erect hanging rafts, resulting in excessive breeding density, which far exceeds the bearing capacity of the marine ecosystem, resulting in obstruction or disorder of the logistics and energy flow cycle of the marine aquaculture ecosystem, causing disease. The decomposition of a large amount of residual bait, debris, fish and shrimp manure, and domestic waste of breeding workers produce a large amount of nitrogen and phosphorus nutrients, leading to eutrophication of the aquaculture waters, providing a suitable ecological environment for red tide organisms, and is the root cause of red tides. Unplanned marine aquaculture is becoming an important source of pollution in coastal waters, and even has a tendency to surpass land-based pollution. For example, in some aquaculture areas in Norway, the degree of pollution damage to the sea area and the seriousness of direct damage to the ecosystem is far more than land-based pollution.
From 2002 to 2017, the EU, the United States, and Japan ranked the top three in terms of import volume among the world’s top ten major importing countries, followed by China, and South Korea, Thailand, Canada, Russia, and Australia ranked fifth to tenth. And Brazil. In terms of import volume alone, China has surpassed the United States to become the world's second-largest importer of marine products after the European Union. All over the world, all forms of mariculture have exploded. This is by no means a new trend, but a major adjustment of the global seafood supply chain. In the past 10 years, the development speed of the global seafood supply chain has been accelerating. FAO predicts that in just 12 years, global seafood production will increase by 40%. Adding value through more precise processing is a common topic in seafood as a whole. Value-added is effective because it meets the needs of today's consumers who are looking for simple protein ingredients that can be added to their recipes. On the one hand, it precisely meets consumers, and on the other hand, suppliers can also maximize the value of seafood raw materials. Organizations such as Icelandic Marine are vigorously pursuing the idea of making full use of each fish, and a profitable way to achieve this goal is to export a series of value-added products from processing to finishing.