10 Jul 2019
Pond Aquaculture and the Risk of Algae Crashes
Written by Zach Stein

One of the great risks in an algae-based aquaculture pond is that of an algae crash. This occurs when algae blooms, reproducing quickly and photosynthesizing during the day only to die off in the late afternoon in early evening. The death of so much organic matter can cause dissolved oxygen levels to plummet as the microbes in the pond begin decomposition and use the available oxygen to break down the dead algae.

In this post we explore the causes and ways to mitigate an algae crash occurring in your ponds.

What Can Lead to an Algae Crash

Do have an algae crash, you generally need to have an algae bloom, meaning a sudden rise in algae levels in your pond.

Blooms tend to occur on hot sunny days when winds are low. While this can create a lot of oxygen in the short term, such a bloom is unsustainable and will lead to a crash that night with significant potential threats to the health and stability of your pond.

What Signs Can Indicate an Algae Crash is Occurring

Sudden changes in water color can indicate that your pond is experiencing a buildup of algae and may be on the verge of blooming.

While changes in water color can be expected through the culture period in a pond, the rapidity of change is where you should pay particularly close attention in addition to any fast changes in turbidity.

If the weather is going to shift to more cloudy or rainy, be on high alert for a potential rise and fall of an algae crash.

How to Mitigate the Likelihood of an Algae Crash

Monitoring your ponds closely is the best way to catch a crash before it happens. Watch the weather and instruct your staff to be on high alert.

Similarly, be very careful of chemical treatments in ponds as overuse can disrupt the natural microbiological cycles.

Finally, be ready with mobile aerators of hydrogen peroxide to provide an additional boost should you detect an algae crash. Increased dissolved oxygen and water exchange can get through the worst of a crash and save your animals from dying or being overly stressed.

Conclusion

We are working on a camera-based sensor that can not only detect the key parameters shrimp and fish farmers care about, but the other parameters that impact the likelihood of an algae crash – watercolor and turbidity. Stay tuned for further updates.