What causes a red tide and how long do they last?

NO one can predict whether or not red tide will be a problem when you are here in 2006. .... In many humans it causes cold like symptoms, burning, runny eyes, runny noses and coughs. It is a safe ... The bloom(s) we had last winter were worse than usual, but far from unprecedented in Florida history. read more

Red tides are usually caused by blooms of phytoplankton, usually dinoflagellates or diatoms (both types of protists), which are often red or green. In some places, red tides are a natural occurrence due to a sudden increase in nutrients from coastal upwelling. In other areas, an influx of excess fertilizer from runoff can cause huge increases in nitrogen and phosphorus concentrations, leading to red tide. read more

Red tides occurred in Florida long before human settlement, and severe red tides were observed in the mid-1900s before the state’s coastlines were heavily developed. However, once red tides are transported inshore, they are capable of using man-made nutrients for their growth. read more

Red tides or harmful algal blooms (HABs) occur worldwide. In Florida, most red tides in marine waters are caused by a naturally occurring microscopic alga, a plant-like microorganism called Karenia brevis or K. brevis. Red tides can last days, weeks or months and can also change daily due to wind conditions and water currents. read more