Sargassum Seaweed & Children’s Health: What You Need to Know

Published on: 05/16/2023
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By Lauren Chiriboga, MD

About Dr. Chiriboga

In the spring, summer and even fall months, Miami’s beaches are the perfect place to take your children for play, exercise and some good outdoor time. Unfortunately, a recent development may pose a threat not only to your family’s enjoyment of the beaches but also the health of you and your children — and that’s Sargassum seaweed.

All about Sargassum

Sargassum, the type of seaweed found on and around Miami’s beaches, is a crucial part of the ocean ecosystem. It provides habitat for many sea creatures, including turtles, and it also helps stabilize the shoreline and prevents erosion due to hurricanes or other storms.

In recent years, the presence of Sargassum in the ocean has expanded rapidly, transforming from a normal part of the ecosystem into a potential problem. Scientific researchers believe this is happening for a variety of reasons, including higher levels of nutrients due to runoff from rivers such as the Amazon, as well as warmer ocean temperatures.

Unfortunately, now Sargassum “blooms” have expanded into floating mats that stretch for hundreds of miles, covering a wide swath of the ocean from Africa to the Caribbean. In 2023, it’s estimated that the Sargassum may produce the largest bloom ever recorded.

When these seaweed blooms are floating out in the ocean, they don’t pose much of a threat to you or your family. However, winds and currents are constantly bringing things ashore, and the same goes for these massive seaweed blooms. On Miami’s beaches, the seaweed typically washes up during the early morning and afternoon tides from March through October.

How Sargassum Seaweed Blooms Can Impact Children’s Health

Obviously, loads of brown seaweed in the water and on the shore is not ideal for your beach outing, but the Florida Health Department says it can pose greater risks for kids, as well. For one, Sargassum emits a chemical known as hydrogen sulfide as it breaks down, which produces a rotten egg smell. This is not pleasant for anyone in the family, but for kids with breathing problems like asthma, it can cause irritation not only to the lungs but the eyes, nose and throat, as well. Exposure to the seaweed itself, as well as the animals who live in it, can also cause skin irritation such as rashes and blisters for children with sensitive skin.

What to Do if Your Child Develops Symptoms

  • If your child develops a rash, it is important to observe them for any other new symptoms because the involvement of two organ systems is highly suggestive of a severe allergic reaction called anaphylaxis. Examples of this include rash and throat itching; rash and vomiting or rash and facial swelling.
  • In the case of a rash with another symptom, take your child to the nearest Emergency Room or Urgent Care Center for evaluation. If your child is already known to experience allergic reactions and has an EpiPen, use the EpiPen. Benadryl can be helpful too, but an EpiPen should always be administered first. EpiPen doses should never be delayed in favor of another medication, like Benadryl. Even if these help, it’s still important to seek emergency care, as more than one dose of epinephrine or other emergency treatments may be needed.
  • If your child has rash and no other symptoms, it is okay to observe them and wait. I recommend calamine lotion, children's Benadryl and/or oatmeal baths as needed for itching. It’s very important to monitor your child for new symptoms, as the onset of anaphylaxis can be delayed and start hours after contact with the allergen, in this case the sargassum seaweed.
  • If your child is having respiratory difficulty, it is critical that you stay calm so as to not worry your child, as fear/anxiety will only worsen your child’s respiratory symptoms. Children with respiratory symptoms after contact with a potential allergen should also be evaluated immediately at ED or UCC.

Planning Ahead

While this is hardly great news for families of children with breathing problems or sensitive skin, the reality is that these Sargassum blooms may be here to stay, says the American Association for the Advancement of Science. This means that families may need to take special precautions before heading out to the beach.

Early each morning, the hardworking crew of Miami-Dade Parks’ beach operations are out cleaning things up before visitors arrive. One of your best bets for avoiding Sargassum is to visit in the morning, after the parks’ cleanup crew has had time to do their work, and before the seaweed starts to wash ashore again in the afternoon.

You can also plan your visits from November through February when the seaweed is less common on Miami’s shores. If you still want to enjoy the beach this spring, summer or fall, that’s okay. But it’s a good idea to pack asthma medication and first aid supplies in your beach bag along with your sunscreen for any kids in the family who might be sensitive to Sargassum.

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