Cyanobacteria can proliferate in standing water, producing lethal cyanotoxins, and can grow into large blue-green algal blooms. “Our latest tests have detected cyanobacterial neurotoxins to be the cause of deaths of hundreds of elephants. These are bacteria found in water,” https://www.the-scientist.com/news-opinion/mass-elephant-die-off-caused-by-cyanobacteria-officials-say-67960?utm_campaign=TS_DAILY%20NEWSLETTER_2020&utm_medium=email&_hsmi=95967127&_hsenc=p2ANqtz-96HpoibkKinbIVjioFqpp6G-qXDgpM405KLrqN_vNnGqbTshzvofFoOY410HBZCzcTCe20f-RigWyWX7ZtEn700DuLSw&utm_content=95967127&utm_source=hs_email
Dinoflagellates: Red tides are caused by the dramatic reproduction of Karenia brevis, a species of dinoflagellate that is common in Gulf waters. Every year when conditions turn favorable, populations of the unicellular alga grow rapidly, dyeing undulating patches of water a brown, green, or rusty hue. Sometimes these events come and go in a matter of weeks or months.
According to statistics kept by the Florida Fish and Wildlife Conservation Commission (FFWCC), the bloom killed more than 1,000 sea turtles, about 200 manatees, and nearly 190 bottlenose dolphins, in addition to countless fish and some economically important invertebrates, such as stone crabs. Humans may have also felt the effects of Florida’s most recent red tide, with the Florida Department of Health noting a small uptick in the number of weekly emergency department visits statewide in July through November 2018 for people reporting respiratory symptoms and red tide exposure. https://www.the-scientist.com/magazine-issue/red-tides-under-the-microscope-66606
Colloidal mineral nanoclusters, especially silver and copper, carrying sufficient Zeta Potential and of size less than 10 nanometers, are likely to be helpful.