Answer:
Red tide occurs in patches of water where certain species of dinoflagellates flourish.
Explanation:
Red tides refer to the noticeable microalgae proliferation that can be recognized for being a big spot in the sea of a characteristic coloration. This phenomenon is caused by two microalgae groups: diatoms and dinoflagellates, both part of phytoplankton.
Red tides occur when certain environmental factors -such as temperature, light, nutrients availability, ph, etcetera- favor the overproduction of these organisms. These species produce toxins that turn to be dangerous for other animal species that feed on them.
Because these microorganisms produce pigments, their accumulation on the sea surface can be noticed as reddish, brown, or greenish color spots of variable extension.