 Studies also indicate that red tide blooms are often terminated by interactions with other microbes such as viruses and bacteria that may either compete for the same nutrients or adversely impact the algal cells.Some studies have considered the maximum critical threshold for vertical thickness of thin layers as three meters, but more recent data has shown that the criteria can be relaxed to five meters.The horizontal extents of thin layers can reach tens of kilometers, and their horizontal to vertical aspect ratio is usually at least 1000