What Are the Prospects for Abalone Farming? Market Potential and Profitability Analysis
Abalone is ranked first among the "Eight Treasures," prized for its delicious flavor, tender and delicate texture, and rich nutrition. Analyzed as a dried product, it contains 40% protein, 33.7% glycogen, and 0.9% fat, along with vitamins and other trace elements. Besides being eaten fresh, abalone meat can also be made into dried products for storage and various canned foods.
Abalone is fairly widely distributed, while the Pacific abalone (Haliotis discus hannai) is mainly produced in the Yellow Sea and Bohai Sea. It is a type of abalone with relatively high economic value, and its output is also relatively large, accounting for about 70% of total abalone production. The shell of the Pacific abalone is large, firm and thick, with three whorls and a sutural line, and a blunt apex. There is a row of protrusions along the shell edge, with 4-5 openings at the end, tubular in shape, and closely adjacent to the outer side of the protrusions runs a groove parallel to them. The shell surface is dark greenish-brown with distinct growth lines and no large folds; the inner surface of the shell is silvery white. Abalone lives a creeping life, inhabiting rock crevices and stone holes surrounded by abundant seaweed, clear water, and good water flow. It hides by day and emerges at night. Adult abalone are omnivorous animals, feeding mainly on brown algae, and also eating green algae, red algae, diatoms, seed plants, and lower plants and animals. The color of the abalone shell is usually closely related to the food it eats.
Current Farming Status
Because abalone prefers habitats with clear water, abundant seaweed, and good water flow in stone holes, the southern boundary of the natural distribution of the Pacific abalone in the Yellow Sea and Bohai Sea is the waters of the Qiansan Islands in Lianyungang City. Due to the unsuitable water depth in the coastal waters of our city, the existing abalone farming method adopts tunnel farming, that is, using artificially purified seawater and taking advantage of the constant temperature characteristics of the tunnel for intensive farming. The main farming site is mainly Shuidiao Village in Liandao Town.
Farming Prospects
Abalone farming is an aquaculture project requiring high input, high output, and high efficiency, and it has a long farming cycle and high technical requirements, so investment risk is high. However, its high profit still deeply attracts farming operators. Taking tunnel farming of 1 million abalone as an example: for a tunnel abalone farm with 1 million abalone, the total investment is about 10 million yuan. Of this, asset investment is more than 6.5 million yuan, production cost is more than 3.6 million yuan, and the farming survival rate can reach 90%. If the selling price is 400,000 yuan/T, sales revenue can reach 13.68 million yuan, achieving total profit and tax of more than 8.7 million yuan, with a sales profit and tax rate of 63.35% and an investment payback period of 2.56 years. With tunnel abalone farming, if technical measures are appropriate and disease control is effective, the prospects are still broad.
Abalone Seedling Rearing Technology
1. Seedling Rearing Conditions
① Mature brood abalone: healthy individuals without injury, with a shell length of more than 6 cm; the gonads appear extremely plump, covering most of the digestive gland, with the gonads protruding beyond the shell edge, and because they are full of sperm or egg cells, the ends become purely round.
② The brood abalone temporary holding pond and juvenile abalone rearing pond should be covered with plastic sheeting on dark days.
③ Collector: mainly made of transparent organic glass, polyethylene plastic algae plates, and film.
④ Collection frame: made by tying steel bars and wrapping them with film, or made by tying thin bamboo or wood.
2. Process Flow
Brood abalone holding → artificial induction of spawning → screening of fertilized eggs → larval collection and culture (timely thinning and separate rearing) → juvenile abalone rearing.
In abalone seedling rearing, bait is especially important and must be prepared in advance. Before larval collection, the collectors need to be pre-colonized with benthic diatoms or soaked in shallow culture ponds for several days, and then these collectors with attached diatoms and unicellular algae are moved into the larval culture pond to collect late veliger larvae.
During abalone seedling rearing, algae culture must be continuously strengthened. In addition to adding an appropriate amount of nutrients in the larval culture pond, lighting should also be enhanced to promote the reproduction rate of benthic diatoms, so that the number of reproducing benthic diatoms remains balanced with the feeding amount of larvae or juvenile abalone. For this reason, fertilizer needs to be continuously added; if the bait is basically insufficient, supplementary bait should be added after changing the water or the bait plates should be replaced to satisfy the larval feeding amount.
3. Disease Control
Vibriosis: Symptoms: the epithelial tissue of the abalone foot falls off, and affected individuals are inactive. In severe cases, there is no response to mechanical stimulation. There are active bacteria in the blood, the body loses color, the tentacles are weak and powerless, the visceral mass shrinks, and the foot retracts. Abalone experience persistent death from metamorphosis to 1 cm, sometimes with peak mortality.
Pathogen: Red abalone is prone to vibriosis when young, and the biochemical characteristics of the isolated Vibrio are close to Vibrio alginolyticus.
Timing: It is generally prone to occur under high temperature conditions or with excessive oxygenation.
Prevention and control: Juvenile abalone should be reared in a suitable environment, and for injured abalone the wounds can be soaked with medicine.
Treatment: ① Soak in a seawater solution of chloramphenicol at 25-50 ppm for 0.5-1 hour, or soak in a 1% seawater solution of compound sulfamethoxazole for 5 minutes. ② Prepare a 5% seawater solution with chloramphenicol or compound sulfamethoxazole and apply it to the wounds.
All the above drug treatment methods require placing the abalone in the air for 10-15 minutes so that the medicinal liquid fully penetrates the lesion, and then returning it to seawater for rearing. In addition, if necessary, repeat the treatment once the next day.
Abalone Grow-Out Technology
1. Grow-Out Conditions : The quality of the natural conditions in Pacific oyster farming sea areas is closely related to their grow-out.
① Terrain: The farming area should be chosen where the tidal flats are relatively flat and the bottom material is preferably mud and sand, convenient for setting up racks and floating rafts. In addition, inner bays with an appropriate amount of freshwater inflow or deep-water locations in reclamation areas are relatively ideal.
② Water flow: The tidal currents in the farming area should be unobstructed, with good seawater exchange conditions, and calm winds and waves or not easily hit by strong winds and waves.
③ Water quality: The seawater temperature should be within the suitable range for Pacific oysters, 5-30 degrees; the seawater specific gravity should be around 1.005-1.025.
④ Bait: The farming area must be a fertile area, convenient for the reproduction of plankton, to ensure abundant bait organisms needed for oyster growth.
⑤ Pollution: The farming sea area should not have serious industrial or agricultural pollution.
2. Grow-Out Production Process Flow
Selection of farming sea area → determination of grow-out method → preparation of grow-out equipment → installation of grow-out facilities → seedling stocking → grow-out management → harvest and processing
3. Main Grow-Out Methods
① Direct grow-out method: traditional farming methods such as stone placement farming, bridge-type farming, stake farming, and bamboo insertion farming. The common feature of these grow-out methods is that the seedling collection device also serves as the grow-out device.
② Seedling separation grow-out method: includes various methods such as tidal flat broadcasting, floating raft or longline hanging culture, and individual culture. Compared with direct grow-out, these farming methods allow artificial control of farming density, effective use of farming waters, shorter farming cycles, and higher yields, and are advanced methods of oyster farming.
4. Tidal flat broadcasting: This is currently a relatively simple method in tidal flat farming of Pacific oysters. Oyster seedlings are directly broadcast at a certain density onto mudflats or tidal flats with muddy and sandy bottom material for grow-out. Hanging culture is further divided into:
① Rack type: Build racks in the farming area using bamboo, wood, or cement posts, and hang the seedling attachment devices on the racks for grow-out.
② Floating raft type: Set up floating rafts in shallow sea areas. The floating raft is made of moso bamboo, and the seedling attachment devices are hung on the raft frame for farming.
③ Longline type: Set up floating lines in shallow sea areas, and hang the seedling attachment devices on the floating lines for farming.
④ Hanging cage type: Single-layer round cage type and the multi-layer net cages used for farming scallops can all be used to hang-culture oysters.
⑤ In addition, Pacific oysters can also be co-cultured with prawns and inter-cultured with algae such as kelp and wakame.
⑥ Bait: They rely entirely on natural bait organisms in the natural sea area, mainly unicellular algae.
⑦ Disease control: In the grow-out production of Pacific oysters, diseases occur relatively rarely. Cases reported abroad include Nocardiosis. In domestic grow-out, the main harm comes from harmful organisms. One category is competing organisms such as rock oysters, barnacles, bryozoans, and serpulid worms, which compete for attachment substrate, food, and oxygen; the other category is predatory organisms such as snails, crabs, the boring bivalve Lithophaga, and scallop copepods, among which the last is the most harmful, and there is currently no effective control method.
Abalone Harvest and Processing
1. Harvest Methods : For abalone cage culture and industrial farming, the harvest method is simple; they can be directly pulled off from the culture strips or culture corrugated plates. For abalone farmed in natural sea areas, harvesting is generally arranged in the seasons of higher water temperature in summer and autumn, convenient for diving operations. The standard for harvesting abalone is generally about 9 cm in size, with 20 individuals reaching 1 kg in weight.
2. Processing Technology : Because abalone is rich in nutrition, tender and delicious, and in abundant supply and good sales, it is currently mostly sold externally, that is, it can be cooked after washing. In addition, it can also be processed into dried products or made into cans.
① Dried product processing: First remove the shell and visceral mass from the fresh product, place it in a vat with 7-8% salt added, take it out overnight, rub and wash off the black pigment and mucus around the foot, wash clean, then put it into a cauldron with water and boil until cooked, take it out, string it with thread, place it on a mat, and sun-dry it.
② Canning: What is commonly used in our country is the boiled can, and the abalone is shelled, and the head and viscera are scrubbed clean before sealing the can.