Chapter 21.2, Problem 1CSC

Just as the invasive Cauterpa seaweed often spreads uncontrollably when introduced to environments free of its normal predators and parasites, populations of toxin-producing dinoflagellates may grow explosively when released into new waters. Red tides have become increasingly common in recent years. One reason for this increased incidence is that dinoflagellate species that can cause red tides have been inadvertently spread around the world by humans. The dinoflagellates travel mainly in seawater that is pumped into the ballast tanks of cargo ships and then discharged at distant ports.

Sometimes, a protist released into a new environment has a damaging impact not because it overwhelms an ecosystem but because it directly causes a disease. What are some examples of such an introduced disease among the alveolates?