Algaecides are not precision guided missiles; they are more like indiscriminate toxic nuclear carpet bombs. They don’t just kill the “bad” algae. They wipe out the entire planktonic ecosystem, including the beneficial zooplankton that consume algae and are essential for a healthy lake.
Zooplankton are the lake’s natural cleanup crew. They graze on algae, keeping populations in check for free, and they become prey for organisms higher up in the food chain to feed upon and that is how a healthy lake stays that way. But algaecides, including physical methods like ultrasonic algaecides, are lethal to them.
This study showed that chemical algaecides are directly toxic to zooplankton and can reduce populations by up to 43% within a single day of application. And although the lethal effect on algae was about twice that – the algae bounced back over 25 fold within just 5 days.
Another study showed that four different algaecides all had exactly the same decimating effect on zooplankton.
On top of that, they are wiping out all the beneficial algae that any surviving zooplankton need to feed on to recover, so the food web disruption inflicts further harm on the survivors.
And an algaecide is an algaecide – it kills things. So they all have the same effect.
This research showed that ultrasonic algacidal devices, marketed as an “eco-friendly” alternative, kill 100% of zooplankton like Daphnia within 30 minutes.
When you kill off the zooplankton, you are wiping out the lake’s natural algae control system. It’s like firing your police force and then being surprised when the criminals take over.
And ultrasonic algaecides – act just like chemical algaecides – they burst open the cyanobacterial cells and release any toxins that they contain.
More algae, more algaecide, more zooplankton killed, more decomposition and oxygen depletion, more hypoxia, even more zooplankton suffocate, less grazing pressure on phytoplankton, more algae, more algaecide – you see the pattern.
