Seaweed, red tide on Florida beaches. Here's what travelers should know

If you're planning a trip to Florida this year, there could be more than just sand on the beaches and fish in the water.

A vast forest of sargassum, a free-floating type of seaweed, is in the Atlantic Ocean and heading toward South Florida this summer. In addition, the NOAA Harmful Algae Outbreak Respiratory Forecast is predicting some coastal areas on the Gulf of Mexico coast of Florida near Tampa to have low to moderate amounts of red tide.

Traveling to Florida this year? Here's what you need to know.

Will red tide affect spring break destinations?

The Red Tide Respiratory Forecast shows the algal bloom is in low to moderate levels along the Gulf Coast, mostly near the Tampa Bay and Clearwater areas.

Sand Key South near Clearwater and Indian Rocks Pinellas County Beach Access currently have moderate amounts of red tide, according to the forecast although those could change to high in the coming days. Near Sarasota, red tide is presently low but could be measured at high by Tuesday.

Here's what the red tide risk chart means:

• Absent/Very low: No risk or very low risk of irritation for people without lung disease. For people with lung disease, leave the beach if you begin to feel the effects.
• Low: Low risk of irritation for people without lung disease. For people with lung disease, leave the beach if you begin to feel the effects.
• Moderate: Moderate risk of irritation for people without lung disease. For people with lung disease, avoid the area.
• High: A high risk of irritation for people without lung disease. For people with lung disease, avoid the area.

What is red tide and is it dangerous?

Red tide is caused by the accumulation of Karenia brevis, a single-celled organism called a dinoflagellate, according to the University of Florida Thompson Earth Systems Institute. Most dinoflagellates are harmless, but some can produce neurotoxins that can cause respiratory problems in humans. It can also attack the central nervous systems of fish and other wildlife.

In Florida, red tide is designated as a "harmful algal bloom."

The National Weather Service keeps track of red tide through the Red Tide Respiratory Forecast. It looks at current wind forecasts combined with Karenia brevis cell counts along Florida's west coast.

Sargassum's winter growth spurt is unusual

According to scientists at the University of South Florida, January was the second consecutive month the amount of seaweed doubled, reaching 8.7 million tons, or enough to fill about 3,000 Olympic size pools.

According to the Palm Beach Post, sargassum reached a peak of 22 million tons in July, a record-breaking year. This year will be another major sargassum year, possibly surpassing 2022.

Sargassum itself is harmless to humans, although the tiny organisms that live inside it may irritate the skin if there is direct contact, according to the Florida Department of Health.

The seaweed also acts as a shelter and food source for fish nurseries, migratory birds and sea turtle hatchlings. In mass quantities, it can clog canals, boat propellers and piles up several feet at the beach. As it decomposes, it emits hydrogen sulfide, smelling like rotten eggs.

More:Huge seaweed blob on way to Florida is 'like a Stephen King movie'

It's still too early to know exactly how much seaweed will reach the beaches in Florida, according to the Palm Beach Post, but it shows up in varying degrees and depths during every major growth year. It rides on the loop current, reaching the Florida Keys and areas north from Miami to Jacksonville.

Sargassum is already proving a problem in Mexico, covering the beaches of Tulum on the Caribbean Sea. It is typically not present in Tulum between October through early spring.

According to the Cancun Sun, tourists are skipping out on Tulum's beaches due to the sargassum and choosing to do more land-based tours and activities instead.