Melissa Harris-Perry: Back with The Takeaway. I'm Melissa Harris-Perry.

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Melissa Harris-Perry: All right. Let's just say the seaweed is not always greener. You see, there is this other kind of seaweed, it's golden brown and it's called Sargassum. Sargassum has been burying beaches in the Caribbean and affecting their tourism industries. It's foul-smelling, an eyesore, and this year, just as tourism was finally approaching pre-pandemic levels, it was everywhere. A record 24 million tons of Sargassum were recorded in the region during the month of June in places like Puerto Rico and Barbados. To find out what's going on here, I went to an expert.

Chuanmin Hu: I am Chuanmin Hu. I'm working at the University of South Florida College of Marine Science as a professor of oceanography. Since 2016, we have been using satellites to monitor and to track Sargassum seaweed in the Caribbean Sea and in Atlantic Ocean. We produce and share monthly report. In this report, we just tell people what is going on right now and what may go on in the next two months for the Caribbean Sea and for the Gulf of Mexico.

Melissa Harris-Perry: Now, what is Sargassum seaweed, is it what we typically think of as seaweed or is it something specific?

Chuanmin Hu: It is a special seaweed. There are many types of seaweed in ocean and this seaweed is specific to the Atlantic Ocean. It lives its entire life in the water, not on the bottom. Many seaweeds live on the ocean bottom. There are two main type of this seaweed, Sargassum fluitans, Sargassum natans, and they reproduce vegetatively, that means they don't have seeds. They're quite abundant in the Gulf of Mexico and the Sargasso Sea for millions of years, but it was not until 2011 did Caribbean Sea start to see a lot of amount of seaweed.

Melissa Harris-Perry: What happened in the month of June in terms of those levels that led to headlines?

Chuanmin Hu: This year is particularly heavy, because in the month of June, the total Sargassum amount in the Atlantic Ocean reached a historical high, a historical record. It is higher than any previous months. That's why it reached the news headline. I'm talking about the entire Atlantic Ocean. If you zoom in to a specific region, the story may be totally different.

Melissa Harris-Perry: Okay, help me to understand that. There's variability both across time and across location?

Chuanmin Hu: Right. Typically, Sargassum peaks in the month of June or July every year. Across the different region in different years, you may have different amount. For example, if we look at the tropical Atlantic, June has the historical record high, but if you look at the Caribbean Sea, the historical record high occurred in 2018. For the Gulf of Mexico, the duration of the Sargassum season is longer this year, but the peak amount is not much higher than previous years.

Melissa Harris-Perry: Why does it matter? Is Sargassum good, bad, or neutral for the ocean, for the seas in which you find it?

Chuanmin Hu: That's a really good question. Most time, Sargassum in ocean is good. It's a habitat for many marine animals including fish, turtle, crab, shrimp, you name it, but when you have a huge amount of Sargassum on your beach, that's very bad. Too much of a good thing makes it bad. It's bad because under tropical sunshine, Florida sunshine, it smells very bad, release a very bad smell, hydrogen sulfide, like rotten eggs. It's bad for human health and it's bad for animals. It attracts insects, bacteria. It chase away tourists, and it's bad for tourism and economy. Also, it's bad for environment because once you want to remove this from the beach, you also remove the sand on the beach. This is very bad.

Melissa Harris-Perry: I want to be sure that I'm clear about this. The Sargassum ends up presumably at high tide, it comes up onto the beach area. The tide goes out and then you've got-- what was valuable right while it's in the water is now sitting out. I hear you saying that it smells bad, but that it's also actually bad for human health. I'm trying to figure out how much of this is just about what we want our beaches to look like, especially if we're paying for a Caribbean vacation. How much of it is about the actual health, especially for those who live there?

Chuanmin Hu: Well, it's bad for human health because it release this bad gas, hydrogen sulfide. That's the same type of gas from a rotten egg. If you have a breathing problem such as asthma, it will get worse. Actually, that's what happened in some of the Caribbean islands. The hospitalization rate went up during the Sargassum season because of this. It's bad for animals because a huge amount of Sargassum on the beach may smother turtle nesting sites. Eventually, this amount of Sargassum on the beach has to be removed physically to have a clean beach, otherwise, the tourists will not go there, and that's why the tourism industry was impacted so much, almost every summer in the Caribbean Sea.

Melissa Harris-Perry: Then you're saying if you remove it, there is no way to do so without also taking some of the beach or some of the sand with you, so it creates a reduction of the sand. Is that part of it as well?

Chuanmin Hu: Yes, that's part of that. Depending on the type of equipment, you may remove more or less sand, but you can't just remove Sargassum without touching the sand because they're on the beach.

Melissa Harris-Perry: Let me ask, I think, what is undoubtedly on all of our minds. Is this related to global climate change?

Chuanmin Hu: Well, remotely. What happened in the past years is related to climate change, but for the individual year, I would say climate variability impacts this through our ocean circulation from wind forcing. In some years, you have stronger winds than other years. That is remotely connected to climate change. From year to year, they fluctuate, and I believe that's what we see in the past 10 years.

Melissa Harris-Perry: Now that we're past summer, we're past June, July, well into August, moving into fall, do you expect to see decline, and will it continue to decline over the course of the fall?

Chuanmin Hu: Absolutely. Every year, the peak months are in summer, so starting from July, the amount starts to decline, and that's what we see in the past months from July to August.

Melissa Harris-Perry: Are there steps that local communities, that oceanographers, or that environmentalists or that ordinary people can take to address this issue going forward?

Chuanmin Hu: They can invent smart ways to make use of Sargassum, so that way people can just go to the ocean, collect the sargassum, make use of them before they land on the beach. Otherwise, it's better to prepare to adapt to the Sargassum invasion because what we see is a new normal for the coming years. They will not disappear. Very likely they will continue this trend.

Melissa Harris-Perry: Do you have suggestions for creative ways to make use of it?

Chuanmin Hu: Well, I'm not the person to talk about how to make use of Sargassum, that's not my field. What I heard was people have been using Sargassum as fertilizer for many, many years. That's not new. People in Texas know how to do this, so they simply go to the beach to collect the Sargassum, wash off the salt, dry them, chop into pieces and bury in soil to use as fertilizer.

People are smart. If you Google online, you'll see how people make use of Sargassum. They make bricks and construction using Sargassum and they make shoes, dinner plates. Also, one time I saw a person teaching people how to make the Sargassum salad.

Melissa Harris-Perry: This is very exciting, both my shoes and my salad?

Chuanmin Hu: Right. I'm not sure if that can be made popular, but at least that's a good try. Also, people are trying to see whether Sargassum can be making pharmaceutical use, medicines and biofuels, but those are under research, so there's no product yet. I believe in the future, we're going to see many types of use of Sargassum because there is a huge amount of them. If the agencies allow harvesting in the ocean, it's almost unlimited.

Melissa Harris-Perry: I love that you've left us with a belief that people are smart, innovative, and that with this huge resource, we can figure out, perhaps, how to make use of this resource. It started out as a bit of a terrifying story but ended up with a good positive way. I appreciate that, Professor Hu.

Chuanmin Hu: Sure. That would be very interesting. We just make a turn of this pathway. Too much of a good thing makes it bad, now we try to make a bad thing back to good again.

Melissa Harris-Perry: Thank you so much for your time, Chuanmin Hu, Professor of Oceanography at the University of South Florida's College of Marine Science. Thank you for joining The Takeaway.

Chuanmin Hu: Thank you.

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