Choose the sea

According to Mr. Nguyen Ton, there was no tissue-cultured variety of algae at the time. Back then, seaweed was obtained from commercial seaweed that growers bought in Ninh Thuan. The way of growing algae back then was to raise them in cages and hang them in the sea. Since the algae farmers do not know how many nets they need to protect themselves from fish, the algae are eaten by the fish when they are young and are therefore not effective. In addition, the consumption of seaweed was still difficult at that time, which led to the development of the seaweed farming industry “at the latest early”.

During a visit to learn more about commercial seaweed cultivation in Phu Yen, a 32-strong delegation from Binh Dinh province was determined to learn the secrets of seaweed cultivation from experienced seaweed cultivation companies.

In the 7-hectare commercial seaweed cultivation area of ​​Okinawa Co., Ltd. in Song Cau city (Phu Yen), the Binh Dinh Seafood Industry delegation was shared by Mr. Le Trung Vinh, the person in charge of Okinawa Co. Ltd., the area The most effective water for growing algae is shallow, clean, sandy water. There must be a sandy beach on the shore so that the growers have a place to dry the seaweed when harvesting, because the harvest of seaweed is very large.

In particular, the sea where algae grow must be avoided where there are cliffs, as the cliffs are the home of cobia and cobia, while algae are the “favorite” of these two fish. If the fish is eaten while the algae are young (it’s only been hanging for about 4-5 days), the algae lose their vigor and are unable to grow. When seaweed grows in the sea without rocky reefs and it is dark, the fish come ashore to look for food and eat algae. If you plant algae in the sea, the algae will be eaten by fish that hide in the reef day and night and cannot stop it.

According to Mr Vinh, growing seaweed in shallow water will be more profitable for farmers. Because the seaweed frequently breaks up and falls off up to a third due to the daily pounding waves, it can fall off even more in the rough sea season. Because algae grows in shallow water, growers can dive into the sea to retrieve the lost algae to keep them from being lost. When algae grows in the sea at a depth of about 2~3m, the grower needs to choose a jet of water flowing on the seabed to spread a net to catch the fallen algae, and then dive to collect them to avoid losses avoid.

According to Mr. Vinh, the seaweed cultivation area reaches 0.9m at the lowest tide, the highest is the best at 2.7m. The seaweed farmers need to know how to dive to recover the broken seaweed to avoid losses and secure an income. Seaweed grown in shallow water also has the benefit of allowing the grower to wade out to tie up the weed seeds. If it is cultivated in deep water, it has to work on a basket boat, which delays the work progress and is more troublesome.

Through practice in the commercial seaweed cultivation area of ​​Okinawa Co., Ltd. in the city of Song Cau, the Binh Dinh Fisheries Sector Delegation obtained the basic knowledge of seaweed cultivation. This is the baggage that will be provided to the fishermen in the Binh Dinh coastal area as part of the roadmap for seaweed farming development in the near future.

“Algae don’t grow when the salt content of the water is over 35%. If the salinity is too high, the body of the algae becomes brittle and breaks easily; But the salt content is too low, algae cannot survive below 27%. The temperature at the water surface in the algae cultivation area also has a direct influence on algae growth. When the water surface temperature of the cultivation area reaches 30℃, growers need to pay attention, when the temperature rises to 32-34℃, they need to lower the hanging ropes deeply to avoid heat, then the algae will grow stably.” said Nguyen Ton Xuan. In the morning, the director of Nhon Hai Tourism and Fisheries Service Cooperative (Quy Nhon City) said.

Choose types of algae for high efficiency

Cartilaginous algae are the most productive type of algae. There are three types of cartilaginous algae, each serving a different purpose. In particular, smooth cartilaginous algae are the highest yielding species and the most popular on the market. Smooth cartilaginous algae have a high starch content and are therefore used in confectionery processing, human food, medicinal and industrial purposes, and therefore always have a higher price than other types of algae. Thorny seaweed is often made into edible salads as it is very crunchy, as is the green porcelain seaweed.

Although the cultivation of smooth cartilage algae has higher economics than two types of thorn algae and green porcelain algae, it still has weaknesses compared to other varieties. For example, green porcelain algae can be cultivated all year round, but this type of algae has low starch content, the algae is brittle, and the smooth cartilaginous algae can only be cultivated for 2 crops per year.

“When smooth cartilage algae grow in Binh Dinh, sowing should be done 20 days before the Lunar New Year, until the third lunar month next year to harvest, because then the windy season will be hot and the plants will not grow. Yield is low.” During this time, farmers can switch to growing thorn algae for production and income throughout the year. Two months later, in the south wind season, we drop the smooth cartilage algae to plant the second crop. It is harvested in the 8th lunar month to avoid the rough sea season, because by this time Binh Dinh is already in the stormy season. Just before the Lunar New Year next year, you can continue to sow seeds to plant again. The smooth-cartilage variety is suitable for the dry season, but needs cool water, so it needs to be stored at the end of December,” said Mr. Nguyen Ton Xuan Sang.

Even during the lull in the rough sea season, seaweed growers can keep the seeds for the next harvest to avoid the cost of buying seeds, according to Mr. Sang. When keeping varieties, it is necessary to avoid areas prone to sweetening. When algae grow in the sea area, the salinity drops to 18S If clean dead seaweed, a salinity of 25 must be guaranteedS above.

According to Mr. Le Trung Vinh, currently, Ninh Thuan mainly cultivates smooth cartilaginous algae for the industry, while Khanh Hoa frequently cultivates green porcelain algae for the tourists. In Binh Dinh, seaweed is mainly cultivated by tourists, however, most of the seaweed is obtained from the wild and not cultivated yet. While tourism in Binh Dinh is currently booming, this is an opportunity for Binh Dinh to develop seaweed farming to both supply the market and reduce exploitation that impacts biodiversity.

“Cartilaginous seaweed has an average yield of 30 tons/ha/year, the selling price is about 0.1 USD/kg, the net profit is about 48 million/ha/year, this is a promising livelihood for the coastal population.” not only used as food and nutritional supplements for humans, but also in many fields such as food additives, animal feed, pharmaceuticals, cosmetics, textiles, biological fertilizers, biostimulants, biopackaging and biofuels,” shared Mr. Tran Dinh Luan, director-general of Fisheries Directorate.