How to manage sea cucumber ponds to get through summer safely

In sea cucumber farming, temperature control is especially important. How can farmed sea cucumbers get through the hot summer? Let us analyze it for you below.

According to this year's meteorological reports: the strongest El Nino phenomenon in history is forming, which will cause flooding in the south and drought in the north this year, and the northern regions are very likely to experience extreme high temperatures, which will bring a severe test to the fragile sea cucumber farming industry. How can sea cucumber ponds prepare in advance to cope with high temperatures in summer, avoid losses and get through summer safely?

1. Regularly improve the bottom to prevent bottom heat

The main causes of bottom heat:

(1) Continuous high temperatures cause the overall water temperature to rise, making it difficult for sea cucumbers to adapt to sustained high temperatures, resulting in “floating sea cucumbers” and “heatstroke”.

(2) Transparency reaches more than 1 m or even the pond bottom can be seen at a glance, there are few algae in the pond, and sea cucumbers lose the natural barrier of algae for shade and light avoidance, or the water level is shallow and sunlight shines directly on the pond bottom.

(3) Organic matter at the pond bottom consumes oxygen, dead grass, dead moss and dead algae rot, the pond bottom lacks oxygen, and putrefactive bacteria produce heat through anaerobic fermentation. This leads to a vicious cycle of pond bottom hypoxia——heat generation——hypoxia.

(4) Too deep a water level (above 1.8 m) causes the pond water to form a thermocline, with no convection between the upper and lower layers, so heat at the bottom cannot be released.

It is recommended to keep the water level at 1.6-1.8 m before the high-temperature period arrives, and every 10-15 days use Diyijing·deodorizing bottom improver or degradation-type bottom improver together with granular oxygen to improve the bottom substrate. During the high-temperature period, improve the bottom once every 7-10 days. If conditions permit, equipped with aerators or spread granular oxygen to prevent geothermal hypoxia. For ponds with a relatively small area, shade nets can be installed to lower the pond bottom temperature.

2. Moderate water fertilization

After using Shui Ziran·077 to control cyanobacteria, moderately use Yushuiwang·quick fertilization type together with Shui Ziran·EM to fertilize water and cultivate algae, reduce transparency, and keep transparency at 30-50 cm. By cultivating algae to reduce transparency, provide shade and heat relief for sea cucumbers through the summer.

3. Water quality must be adjusted early and finely

Entering the high-temperature season, pond water quality must be adjusted early and finely, and detoxification must be carried out regularly. No product should be used at full dose or overdosed all at once. Therefore, in the high-temperature season, microecological preparations should be used in small amounts many times, which can both ensure satisfactory water adjustment and bottom protection effects and avoid the occurrence of the phenomenon.

During the high-temperature period, dissolved oxygen, bacteria, algae and nutrients change frequently, biomass continues to increase, and biological metabolic capacity strengthens. As water temperature continues to rise, pond bottom pollutants easily float up, organic matter and dead algae increase, which easily causes foam to accumulate on the water surface, weakens water body permeability, deteriorates water quality and bottom substrate, and may even produce a fishy odor at the downwind area.

Adjustment plan: on the first day in the morning, use Shui Ziran·dedicated detoxification one bottle for 3 mu, together with Shui Ziran·EM one barrel for 10 mu to stabilize water; in the afternoon, use Diyijing·deodorizing type one pack for 5 mu, focusing on spreading it at the downwind area and four corners of the pond to improve the bottom. On the second day in the morning, use Shui Ziran·EM one barrel for 15 mu, together with Shui Ziran·dedicated water adjustment one pack for 5 mu, to adjust water color.

4. Scientific water exchange

Water exchange is the most direct and effective way to improve water quality. Adding fresh seawater can increase dissolved oxygen in the water, reduce the concentration of metabolic waste, regulate salinity and pH, and at the same time bring in large amounts of benthic diatoms and organic debris, improve the biological composition structure of the pond water, and provide feed for some small-sized spiny sea cucumbers that have not entered aestivation.

1. Increase the amount of water exchange. For sea cucumber ponds in summer, on the premise of ensuring relatively stable factors such as water temperature and salinity, if there are natural water intake conditions, water should be taken in whenever there is a tide; if there are no natural tidal water intake conditions, mechanical water intake should still be maintained every day, and the daily water exchange volume should reach more than 20%, maintaining a relatively high water level of 1.5-2 m to reduce the impact of light and high temperature on pond water. However, if there are several consecutive days of cloudy and windless weather, the water level can also be appropriately lowered to facilitate upper-lower convection of pond water and prevent pond bottom hypoxia.

2. Observe the water quality conditions in the sea area and in the pond before exchanging water. If seawater is polluted or undesirable water quality conditions such as red tides occur, do not take in water; especially note that after heavy rain, if the external seawater quality is unclear, do not blindly take in water; in addition, if the pond water quality is relatively good, appropriately exchange less water, and if the pond water quality deteriorates, increase the water exchange volume; also note that when taking in water, try to avoid the beginning and end of the tide.

3. Adopt the method of adding water while draining water for water exchange, which can keep the pond water in a micro-flow state, facilitate the diffusion of dissolved oxygen, and prevent local hypoxia at the pond bottom and pond corners.

4. Prevent rainwater backflow and promptly discharge fresh water in the pond. First, before rainfall, first drain about 1/3 of the original pond water and then immediately add water to the highest water level; second, often check whether there are channels around the pond for land rainwater to enter the pond, and prevent large amounts of rainwater from entering the pond; third, during heavy rainfall, promptly open the freshwater drainage gate boards and freshwater drainage pipes to overflow the surface low-salinity water from the upper layer, ensuring that the salinity of the upper and lower layers of pond water is basically consistent, and preventing stratification of pond water caused by different specific gravities of upper and lower water layers, which would prevent oxygen-rich upper-layer water from reaching the bottom layer through vertical convection, leading to pond bottom hypoxia and increased contents of harmful substances such as ammonia nitrogen, hydrogen sulfide and nitrite.