The "guts" of a cactus may be able to solve a problem that's plaguing fish farming. These cacti may be able to purify contaminated water for farmed fish in order to help clean up the local ecosystem and prevent water waste.
Mucilage, the guts of a cactus, of some common cacti can clean drinking water. Prickly pear can be boiled in order to capture particles in sediment-laced dirty water. Knowing this, the researchers decided to experiment with cacti to possibly use it on a larger scale.
After the Deepwater Horizon oil rig spill in 2010, the researchers explored the possibility of using cacti to clean up oil contaminated seawater. The experiments never moved beyond bench scale. However, cactus mucilage was proven to be an effective oil dispersant.
In this latest effort, though, researchers looked at whether cactus extract could be used to clean up recirculating aquarium water. This, in particular, is important for aquaculture tanks and ponds.
In aquaculture, bacteria can develop and create unpleasant, smelly compounds, such as 2-methylisoborneol (MIB) and geosmin. These compounds not only affect the smelly of the water, but also can affect the flavor of the fish. Current practices include purging both the fish and the tanks with fresh water right before harvest; however, this can take months and uses a large amount of water. It would be a lot easier (and cheaper) to find a method to keep the water clear without this system.
In this case, the researchers used mucilage to test whether it could be used. While the researchers have found that its effective, they're currently looking at the mechanism that allows the mucilage to be a purifier.
Currently, the scientists are studying the chemical composition of these cactus guts in order to synthesize it in a lab. They are also developing a prototype recirculating aquaculture system that uses cactus extract as a cleansing agent.
The findings could be important for aquaculture. It could give fish farmers a way to keep their ponds clean and clear without the need to flush out excess waste water. Instead, the cactus could act like a purifier and thus clean the water without the need for excess flushing.
