Record levels of sargassum seaweed are washing ashore on Florida's most popular beaches this spring break, greeting millions of vacationers with foul smells, health concerns, and thick mats of brown algae along the coastline.

According to The Weather Channel, the University of South Florida Optical Oceanography Lab's Sargassum Watch System is reporting record-high sargassum levels across parts of the Caribbean, the western Atlantic, and the Gulf, including Florida beaches. In just the last 30 days, sargassum across the Atlantic has surged from just under half a million tons to nearly 1.7 million tons. Projections show those amounts growing even higher in the coming months.

Early accumulations have already hit beaches in Barbados, Dominica, and the French Antilles, as well as popular spring break destinations like Tulum and Cancun in Mexico. The situation in Mexico has become so serious that the Mexican navy has deployed containment barriers and amphibious collection boats working around the clock to hold back the seaweed.

Sargassum is a naturally occurring brown seaweed that floats in massive mats across the ocean's surface. In open water, it plays a vital role in ocean health. It provides food, shelter, and breeding grounds for hundreds of marine species, including tuna, swordfish, sea turtles, and crabs. It also helps reduce beach erosion.

The problem begins when winds and ocean currents push it ashore. Once beached, sargassum decomposes and releases hydrogen sulfide, the same gas responsible for a rotten egg smell, which can cause headaches and respiratory irritation. According to the National Oceanic and Atmospheric Administration (NOAA), sargassum also contains high levels of arsenic, heavy metals, and other contaminants that can be harmful to humans.

In large amounts, beached sargassum can form "brown tides" near shore, damaging coral reefs and harming coastal plant and animal life.

Florida communities are fighting back, but it's an uphill battle. In Miami-Dade County, workers drive tractors with rear-mounted blades along 17 miles of beaches every day to mix and blend the sargassum at the high tide mark. At four state-approved "hot spot" locations, a county vendor uses specialized barber-rake tractors to remove heavier buildups.

Where heavy machinery can't reach, crews use hand tools and wheelbarrows. The Environmental Protection Agency (EPA) notes that containment booms and offshore barriers have also been tried, but "with mixed results."

Experts say vacationers can still enjoy Florida's beaches with a little flexibility and advance planning. Every Tuesday, NOAA publishes a Weekly Sargassum Inundation Risk outlook that pinpoints areas facing the heaviest buildup. Checking this resource before heading to the beach can help visitors find cleaner stretches of sand nearby.