The term 'Red Tide Cause' refers to the cause of a red tide, which is an algal bloom caused by an increase in the population of certain species of ALGAE. The ALGAE responsible for red tides are typically dinoflagellates, which are single-celled organisms that produce toxins that can be harmful to marine life and humans. The cause of red tides is usually an increase in nutrients in the water, such as nitrogen and phosphorus, which can come from agricultural runoff, sewage, or other sources.