Crayfish Farming Management Methods for the Plum Rain Season: Do These 3 Things Well to Transition Safely

In July, crayfish farming areas also enter the hot and rainy plum rain season, which can be a hurdle in aquaculture. A slight carelessness in farming management can lead to reduced production, or even a total loss. So what are the crayfish farming management methods for the plum rain season?

Crayfish Farming Management Methods for the Plum Rain Season

1. Manage aquatic plants

The plum rain season is a critical period for controlling aquatic plants, because this is when aquatic plants grow most vigorously. If they are not properly controlled in the early part of the plum rain season, it will affect the ecology of the entire farming environment later on.

First, for Elodea (Elodea nuttallii) that is growing excessively, the plants should be appropriately pulled apart to open up the row spacing, and at the same time, oxidative bottom-improving agents and root-promoting plant fertilizers should be used regularly to increase dissolved oxygen at the bottom, reduce yellow roots and black roots, promote the growth of white roots, and prevent root rot and floating plants during the high temperatures of July. For Elodea in deep ditches and Elodea heavily attached with Cladophora, it should be removed promptly.

Second, Hydrilla verticillata (black algae) will most likely develop problems during the plum rain season. Besides rampant pest infestations, the problems of yellow roots and black roots are also prominent. In ponds with dense aquatic plants, the plants tend to float to the surface, accompanied by problems such as debris clinging to the plants and slow growth. Once the above problems appear, the water level should be lowered promptly during the plum rain season, oxygen should be increased and the bottom should be improved, and plant-rescue products should be used promptly to save the plants. Only with a pond of good aquatic plants can the crayfish safely pass through the high-temperature period.

Finally, for those preparing to set nets after the plum rain season, before removing the enclosure nets on the flat fields, snails or juvenile snails can be appropriately stocked, which helps preserve the flat-field grass and Hydrilla verticillata.

2. Do a good job of preventing crayfish from escaping

The most direct impact of the rainy season is that it raises the water level of the farming pond, which ultimately causes the pond water to overflow the banks and allows crayfish to escape, and in severe cases even causes the pond embankment to collapse, resulting in irreparable losses.

Therefore, before the rainy season arrives, we need to do basic work such as inspecting and repairing the escape-prevention nets, lowering the water level of the farming pond, clearing the inlet and drainage channels, and reinforcing the pond embankments; and during the rainy season, pond patrols need to be intensified to promptly drain excess water from the farming pond. Prevent problems before they occur, and patrol frequently.

3. Increase oxygen promptly

With prolonged rain, the environment remains in a low-pressure state for a long time, which easily leads to a decrease in the dissolved oxygen content of the farming pond. And when crayfish remain in an oxygen-deficient environment for a long time, it will cause irreversible harm to the crayfish, resulting in slow growth and, in severe cases, directly leading to death. Therefore, during long rainy periods, the dissolved oxygen in the water body needs to be closely monitored, and when dissolved oxygen is low, aeration equipment should be turned on promptly or oxygen-increasing agents should be splashed.

4. Regulate water quality

Since May, rainfall has increased, and especially during the plum rain season, the phenomenon of muddy water caused by oxygen deficiency will become more serious. So the oxygen deficiency problem must be solved first, then the water should be clarified, and afterward attention should be paid to stabilizing the water. At the same time, fertilize the water to cultivate beneficial algae, especially algae at the bottom layer, to increase dissolved oxygen in the pond and improve the self-purification capacity of the water body.

Second, increase the intensity of bottom improvement and water regulation, use oxidative bottom-improving agents regularly to improve the bottom environment and degrade organic matter at the bottom. Use low-oxygen-consuming Bacillus or photosynthetic bacteria once every 7-10 days to regulate water color and prevent dense water and blue-green algae.

In addition, for ponds fed with ice-frozen fish where undesirable water colors appear due to an excess of Euglena, Cryptomonas and the like, attention should be paid to bottom improvement, using water-clarifying bacterial strains, while also supplementing benthic algae to balance the algae and improve water transparency.

The plum rain season is a critical period for crayfish farming during the year. Only a smooth transition can ensure production, and farmers must not take it lightly.