Method for removing green algae in the middle and late culture stages of Porphyra yezoensis

Abstract

Disclosed is a method for removing green algae in the middle and late culture stages of Porphyra yezoensis. The method is characterized by comprising (1) preparing 50-100ml of 10% sodium hypochlorite solution, adding cleaned and disinfected seawater to reach a volume of 1L, adding trisodium phosphate and disodium phosphate at molar ratio of 3:1 to the above solution, and adjusting pH to 9.0-9.5 for later use; (2) during the culture process after nori mesh screens are placed into the sea (i.e. from September 21 to April of the next year), performing smear operation in the sea; (3) during the process to clear green algae, adding analytical grade citric acid to the solution of step (1) to allow pH value of the solution to be about 5.0-5.5; (4) smearing the solution obtained in step (3) in batches every day to green algae attached to mesh screens, raft frames and cables so that the damaged green algae break under the effect of seawater flow and enter the sea; and (5) smearing with the solution obtained in step (3) once every two months. The method of the invention can remove green algae attached to mesh screens, raft frames and cables in the middle and late culture stages of Porphyra yezoensis.

Description

technical field [0001] The invention relates to a method for removing green algae, in particular to a method for removing green algae in the middle and later stages of Porphyra zebra cultivation. Background technique [0002] The growth cycle of laver is divided into seedling raising, seedling picking, net culture (into the sea area) and harvesting. [0003] From late April to early and mid-September every year, put the grown vegetables of Porphyra thallus mature (formation of fruit spores and sperm sacs) in a container filled with clean sea water, release the fruit spores and attach them to clam shells or oyster shells On the top, enter the stage of filamentous body cultivation, that is, the stage of seedling cultivation. Chlorella hardly affects the process of laver seedling cultivation. The seawater for seedling cultivation is generally clean seawater after exposure and precipitation, so only laver spores will adhere to the net curtain; the stage of seedling collection i...

AI Technical Summary

Problems solved by technology

[0007] 2. Hydrochloric acid is harmful to the environment and can cause pollution to water and soil. Low concentrations of hydrochloric acid will also kill marine phytoplankton and destroy ecological balance.

[0008] 3. Hydrochloric acid is strongly acidic, which reduces the pH of some sea areas, and large-scale use will increase ocean acidification in coastal areas

[0009] 4. Hydrochloric acid is a hazardous chemical, and there are environmental risks during storage

[0010] 5. The acid treatment solution can remove 90% of green algae by soaking, but it will also have a great impact on laver. The laver fronds become smaller and yellow, which will affect the quality of laver.

Moreover, this method is not only cumbersome to operate and has a large workload, but also cannot prevent the green algae from continuing to grow after the net curtain is put into the sea area, and the green algae on the raft frame and cables still cannot be removed.

[0011] Therefore, so far there is no relatively ideal technical solution for green algae processing in Porphyra zebra cultivation, and it remains to be solved.

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