Red tide is so named because of the red color imparted to the water as a result of a population explosion of algae called dinoflagellates. what is another term used by marine scientists to describe such a population explosion?

The term that nay be used is the harmful algal bloom.
Red tide is a phonomenon caused by algal blooms during which algae become so numerous that they discolor coastal waters. The algal bloom may also deplete oxygen in the waters and/or release toxins that may cause illness in humans and other animals. 

Where's the picture of the model?