Hydrodynamic cavitation in aquaculture

What cavitation has been tested for in aquaculture

Research on cavitation for aquaculture follows three lines: getting oxygen into water with Venturi devices, reducing cyanobacteria, and treating culture water. Most of it was done in laboratories and tanks, and none of the cited studies measured fish or shrimp.

A cavitation device speeds water through a constriction until its pressure falls below the vapor pressure, and the vapor cavities collapse as the pressure recovers. A review stresses that reactor design largely determines how effective and economical the process is Sun et al., 2020. The principles are in What hydrodynamic cavitation is and Cavitation, gas dissolution and fine bubbles.

Venturi oxygenation: what tank tests measured

Venturi aerators have been measured in tanks, not against paddlewheels in working ponds. Paddlewheels and propeller-aspirator pumps are the most widely used pond aerators, at 1–2 kW/ha in some fish culture up to 15–20 kW/ha in intensive shrimp culture Boyd, 1998.

A Venturi aerator speeds water through a narrow throat, where the pressure drops and air is drawn in. In a 1,124 L tank, an aerator with optimized geometry transferred 0.0216 kg O₂/h, a standard aeration efficiency of 0.611 kg O₂/kWh Yadav et al., 2021. A solar-powered prototype with four injectors and a 0.3 kW pump reached 0.681 kg O₂/kWh and a SOTE of 7.32% in a 4,000 L pool Dayıoğlu, 2022. In four days of simulated operation with deliberate de-oxygenation, its efficiency peaked at 0.474 kg O₂/kWh, while dissolved oxygen (DO) ranged from 1.05 to 6.65 mg/L.

These are aeration results. The abstracts do not report cavitation at the throat or performance in a stocked pond. Nanobubble oxygen results are in Oxygen management and sediment.

Cyanobacteria: collapsing gas vesicles

In laboratory work, brief cavitation made Microcystis sink rather than burst. The cyanobacterium stays afloat with intracellular gas vesicles, and cavitation disrupted them.

A 10-minute treatment lowered Microcystis cell density by 88% and chlorophyll-a by 94%, measured after 3 days of culture Li et al., 2014. Electron microscopy linked the settling to disrupted gas vesicles, and the cells did not break. Free radicals did little damage; treatment time and pump pressure mattered most.

A follow-up found selectivity. Microcystis fell by nearly 90%, while the green alga Chlorella, which has no gas vesicles, fell by 63% with its photosynthesis unaffected Li et al., 2015. In 10 minutes, cavitation reached 88% algal removal against 39% for ultrasound.

Hydraulic jet cavitation, tested on cultures and on real bloom biomass, removed up to 99% of the cyanobacteria Jančula et al., 2013. Flow cytometry detected no membrane damage, which the authors read as a low risk of toxin release, and the green alga Chlorella kessleri was not affected negatively. Bubble work on lake blooms is in Remediation of lakes and rivers.

Scaling up, and adding ozone

Larger reactors have ruptured cells, and the strongest results used ozone as well. In a pilot loop, an 11 kW pump drove 35 L of field-collected Microcystis through a jet pump reactor; cell disruption reached 17.4% after 6 hours, and at most 25.54% at 900 kPa Xu et al., 2022. An optimized reactor reached at most 39.9% removal, using about 18% of the energy of ultrasonic cavitation Chai et al., 2025.

With ozone fed to the pump suction, cavitation and ozone together reduced Microcystis by 91% in 5 minutes. Over 10 minutes, cavitation alone had removed less than 15% and ozone alone less than 35% Wu et al., 2012. The chemistry is in Advanced oxidation processes (AOPs).

Treating water in recirculating systems

The evidence for recirculating systems is one study. Ozone-assisted cavitation degraded eight antibiotics in aquaculture seawater within 20 seconds; DO rose from 9.79 to 13.19 mg/L and nitrite nitrogen fell from 0.14 to 0.01 mg/L Huang et al., 2025. The authors called for field-scale validation.

Off-flavor work has used ultrasound instead: 15 minutes at 850 kHz reduced geosmin and 2-methylisoborneol in 250 mL samples of recirculating-system water Nam-Koong et al., 2016. Ozone results on fish and shrimp bacteria are in Disease control and biosecurity.