What the colors of red tide? It creates toxins that affect aquatic life's central nervous system and they die. They also bother human's respiratory system, especially those with asthma and emphysema.
What the colors of red tide? Red brown, rusty orange, and shades of green.
Is red tide new to Florida? And, why it is so frequent in the Gulf? No, it's been around since the 1700s. According to the FWC, "K. brevis thrives in high-salinity (salt content) areas [of Florida] but can tolerate a wide range of salinities and temperatures. The species forms nearly monospecific (single species) blooms by outcompeting or excluding other phytoplankton species.
The following research is from Mote Marine Laboratory: "The Florida red tide alga, Karenia brevis, needs the following components to form a bloom. The first is biology — the organism must be present in the water and it must out-compete other phytoplankton. The second is the correct chemistry — this includes the appropriate temperature, salinity, and nutrients that it needs to grow and multiply. The third component is the right physical conditions to concentrate and transport K. brevis. The fourth component is ecology – the presence or absence of other life forms, such as other marine algae that may encourage or inhibit K. brevis blooms" (Mote FAQs)