> Combined low concentrations of copper (5 μg/l and chlorine (50,μg/l have been effective in preventing both micro and macro-fouling in over 120 seawater installations since 1987.
It's also done in freshwater (great lakes) to prevent zebra mussels from clogging the intake pipes. Things like to grow where other things bring food by for free, and are sheltered from predators.
> Combined low concentrations of copper (5 μg/l and chlorine (50,μg/l have been effective in preventing both micro and macro-fouling in over 120 seawater installations since 1987.
https://www.researchgate.net/publication/242186534_FOULING_P...