rocky or pebble areas. These tropical populations often undergo seasonal cycles of growth and decay in concert with seasonal changes in sea temperature. In tropical Sargassum species that are often preferentially consumed by herbivorous fishes and echinoids, a relatively low level of phenolics and tannins occurs. Inundations In limited amounts, washed-ashore Sargassum plays an important role in maintaining Atlantic and Caribbean coastal ecosystems. Once ashore, sargassum provides vital nutrients such as carbon, nitrogen, and phosphorus to coastal ecosystems which border the nutrient-poor waters of the western North Atlantic tropics and subtropics. Additionally, it decreases coastal erosion. However, beginning in 2011, unprecedented quantities of Sargassum began inundating coastal areas in record amounts. Coastlines in Brazil, the Caribbean, Gulf of Mexico, and the east coast of Florida saw quantities of sargassum wash ashore up to three feet deep. The first major Sargassum inundation event occurred in 2011 and had a biomass increase of 200 fold compared to the previous eight years average bloom size. Since 2011 increasingly stronger inundation events have occurred every 2–3 years. During a Sargassum inundation event in 2018, one Sargassum bloom measured over 1600 square kilometers, more than three times the average size. Recent inundation events have caused millions of dollars of lost revenue in the tourism industry, especially hurting small Caribbean countries whose economies are highly dependent on seasonal tourism. While the Sargasso Sea is a known source of sargassum blooms, variations in the sargassum types composing these inundation events have led researchers to believe that the Sargasso Sea is not the point of origin of inundating Sargassum. Sargassum natans I and Sargassum fluitans III are the dominant sargassum species found in the Sargasso Sea. Recent net sampling studies have found Sargassum natans VIII, a previously rare type, is constituting a dominating percentage of Sargassum biodiversity in the Western Atlantic and Sargasso Sea. Biological impacts Unprecedented Sargassum inundation events cause a range of biological and ecological impacts in affected regions. The decomposition of large quantities of Sargassum along coastlines consumes oxygen, creating large oxygen-depleted zones resulting in fish kills. Decomposing sargassum additionally creates hydrogen sulfide gas, which causes a range of health impacts in humans. During the sargassum inundation event in 2018, 11,000 Acute Sargassum Toxicity cases were reported in an 8-month span on just the Caribbean islands of Guadalupe and Martinique. Massive amounts of floating sargassum present a physical barrier preventing corals and seagrasses from receiving