Since sea cucumbers generally need a growth period of 3-5 years, and most of them grow in the deep sea at a depth of 5 or 6 meters to 20 meters, the growth cycle is long, and it is inconvenient to harvest them, so the annual harvest is far from satisfying the needs of the market.
In recent years, China's sea cucumber artificial nursery industry has been developing rapidly, providing mature technology and sufficient seedlings for sea cucumber large-scale aquaculture, and fishermen around the world have summarized and worked out a variety of different forms and methods of sea cucumber artificial aquaculture new technology according to the geographic advantages of the local coasts and mudflats, islands and harbors.
Raft culture method
Raft culture is to use the net box similar to fish farming to carry out artificial culture of sea cucumber in the sea. The best choice for the sea area of raft culture is to choose a good harbor surrounded by mountains on three sides, with gentle back wind and water depth of 5-9 meters. The nets are made of plates or logs of moderate thickness with a side length of 4 meters or 6 meters, and the height can be set at 3-4 meters according to the depth of the sea water and the size of the tide difference.
Every year in spring and fall, when the seawater temperature reaches 8-12 degrees Celsius, it is the best time to put in sea cucumber seedlings. At this time, the sea cucumber seedlings in the aquaculture workshop are about 200-400 heads per kilogram, because the individuals are large and strong, and the survival rate can reach more than 95% at this time. A 6-meter-square net box like this can put in about 20-25 kilograms of sea cucumber seedlings of about 200 heads per kilogram.
In sea areas with more bait and floating mud, the food on the net box can basically meet the needs of sea cucumbers. If it is found that there is not enough food, it is necessary to feed. The easiest way is to choose the sea area with smooth flowing water and drag some microorganism-rich mud for supplementation, or you can make some homemade synthetic bait with algae for feeding. Normally, you should check the nets frequently whether they are broken or not, and remove the natural enemies such as fish fry, crabs, starfish and other debris such as oysters and sponges in the nets in time.
The biggest advantage of raft culture of sea cucumbers is that it is easy to manage and has a high harvest rate, and it usually takes about 2 years to harvest the finished sea cucumbers.
Beach Captive Farming Method
Wherever there are shrimp ponds and salt ponds, they can be farmed with a little remodeling. It is also possible to dig and build a pond on the beach. Usually choose the beach is not easy to wind and tide damage to build pools. The size and shape of the pool depends on the geographic environment, the general requirements of the length of not less than 50 meters, not less than 30 meters wide, the depth of water at low tide between 0.8-1.3 meters. "Captive pool" set in and out of the water gate each one or more, the gate should be installed at the filter, to prevent fish and a variety of enemies to enter.
The bottom of the pool simulates the natural shape of the seabed, with stones and hollow bricks piled up in the shape of long rows and ridges, and there is space for the sea cucumbers to live and make their homes. The bottom of the pool should maintain the original ecological environment of the sea cucumber as much as possible, and various kinds of seaweeds such as kelp, wakame, seaweed and attached diatoms should be transplanted. Before casting seedlings, the breeding place should be sterilized and exposed to the sun. Disinfection is generally used lime water and other splashing.
The density of seedling placement in the pool is generally 10-15 per square meter. The water exchange of beach captivity mainly utilizes the difference between high and low tides of seawater for water exchange, and can also use artificial water exchange. Generally, it is required that the daily water exchange is about 1/3-1/4. The bait for captive sea cucumbers is mainly natural bait, and synthetic bait is added appropriately according to seasonal water temperature, individual sea cucumbers and stocking density.
Captive sea cucumbers are characterized by small investment, easy management, close to natural environment, high recovery rate of sea cucumbers and fast growth. The growth cycle of captive sea cucumbers is usually about two years.
Sea Bottom Sowing Method
This method is mainly to make up for the lack of natural reproduction of sea cucumbers, and increase the density of sea cucumbers in the sea area by artificially putting sea cucumber seedlings, so as to increase the production of sea cucumbers. In the spring and fall seasons when the water temperature is suitable, when the natural water temperature reaches 8-10 degrees, choose the days with clear weather and calm winds and waves, put the sea cucumber seedlings of more than 2-3 centimeters into mesh bags or bamboo baskets, and put them into the seabed among the reefs by the divers, so that they can crawl and evacuate naturally, and choose the place to settle down freely. The density of bottom sowing is generally 6-7 per square meter. Bottom sowing should pay attention to the temperature difference between the temperature of the pool and the temperature of the sea area, generally not more than 2 degrees. The sea area should be chosen to have smooth flowing water, rich bait and less enemies. Gravel and mud and sand between the sea area.
The main features of this method are simple and easy to operate, low cost, the sea cucumber grows in the natural environment, the growth rate is faster, usually 2 years time can be harvested.
Generally speaking, the combination of raft culture and beach captive culture, raft culture and seabed seeding is a more scientific culture method.
Artificial culture of sea cucumber is an emerging mariculture project in recent years. Due to the maturity of culture technology and the rapid development of culture area, it has swelled into an important pillar industry. We believe that with the continuous progress of science and technology, it will have an important impact on the artificial culture of sea cucumber and the deep processing and comprehensive utilization of sea cucumber, and usher in a better tomorrow for our life.