"This year could be the biggest year yet," Brian Lapointe, an algae specialist and research professor at Florida Atlantic University's Harbor Branch Oceanographic Institute,It is unclear exactly what is causing this recent trend, but the most likely explanations relate to human activity.One potential cause is water pollution.
A 2021 study co-authored by Lapointe looked at the chemistry from the 1980s to 2019 found sargassum collected in recent years contained nitrogen levels"It's almost like sargassum is a barometer for how global nitrogen levels are changing,"The combustion of fossil fuels releases carbon dioxide, which is increasing the concentrations of CO2 in the air and the oceans, which may be feeding the sargassum’s growth.
"The world is changing, and part of that is the oceans are getting warmer, and algae seems to be able to grow over a longer period of the calendar now then used to be the case," Dave Tomasco, executive director of the Sarasota Bay Estuary Program,The EPA also notes that “warmer water is easier for small organisms to move through and allows algae to float to the surface faster” and “algal blooms absorb sunlight, making water even warmer and promoting more blooms.
It’s not just the warmer temperatures. Second-order effects of climate change may also play a role. For example, since warmer air causes more evaporation, rainstorms are growing more intense. Those storms bring flood waters filled with nitrogen-heavy runoff out to sea.that have caused dead fish to show up in droves on Florida's coastline.
When sargassum washes up on beaches, it decomposes, releasing hydrogen sulfide, which gives off a rotten egg-like smell. Exposure to hydrogen sulfide can irritate the eyes, nose and throat. And although sargassum itself is not harmful to humans,"tiny sea creatures that live in Sargassum can cause skin rashes and blisters,"