National Geographic News
Photo of oceanographer Sylvia Earle swimming with fish.

Ocean explorer Sylvia Earle swims among fish while on an expedition to the Sargasso Sea.

Photograph by Shaul Schwarz, Getty

Jane J. Lee

National Geographic

Published March 14, 2014

Five countries signed an agreement this week committing to the protection of the Sargasso Sea, which occupies a vast stretch of the North Atlantic Ocean around Bermuda.

The Sargasso has long attracted the attention of conservationists and scientists because it hosts a rich diversity of wildlife, including leatherback sea turtles, humpback whales, and bluefin tuna. The animals eat and take shelter in a seaweed called sargassum, which floats in massive quantities in the area—some say it looks like a golden, floating rain forest—and gives the sea its name.

Locator map of the Sargasso Sea.
NG Staff

Fishing and shipping traffic threatens to unravel this biologically rich ecosystem, on top of broader threats like climate change and ocean acidification.

The new nonbinding agreement on the Sargasso, called the Hamilton Declaration, is a first for the high seas.

Nations are entitled to govern the ocean 200 miles (322 kilometers) out from their shores. But beyond that, the high seas—which cover about half the surface area on Earth—are like the Wild West. Many nations use those waters for fishing or to extract resources like minerals, but no one country governs them.

Former chief scientist for the U.S. National Oceanic and Atmospheric Administration, Sylvia Earle has worked for years to set up some kind of governance framework for the high seas. "Half the world," she says, "is beyond national jurisdiction."

We spoke to Earle, a National Geographic explorer-in-residence, about what this latest agreement between Bermuda, the U.S., the Azores, Monaco, and the U.K. means for the future of the Sargasso.

Photo of Sylvia Earle photographed on a boat.
Sylvia Earle, pictured here on an expedition to the Sargasso Sea, calls the area a floating rain forest because of the diversity of animals found within its seaweed.
Photograph by Shaul Schwarz, Getty

Tell us about the Sargasso Sea.

Its boundaries are actually liquid—it's defined by currents.

[It has] these floating islands of sargassum. Sargassum is two kinds of seaweed that are never anchored. Most seaweeds grow attached to something, but not these two kinds. They are a leafy, golden-brown, small, shrubby kind of seaweed that has distinctive gas-filled, berry-size floats that maintain the sargassum at the [ocean's] surface.

We refer to it as the floating, golden rain forest of the sea, populated by small, medium, and large animals. Some are only found there on the sargassum.

There are two great populations of freshwater eels that grow to maturity far inland in rivers [in North America and Europe], but then go to the Sargasso Sea on a remarkable journey to spawn.

The very young eels don't even look like eels—they look like transparent leaves with eyes. Ultimately, they transform into something that looks like an eel. They live about three years in the plankton until they find their way back to the rivers their parents came from.

If someone went out to this area, what would they see?

It's seasonally abundant. That is, you can go sometimes into the Sargasso Sea and not see very much. But other times, you can encounter masses [of sargassum] that do really look like great islands. Christopher Columbus described encountering these great masses of seaweeds. It's like having a garden out in the open ocean. It's why so many creatures find shelter out in the open ocean.

What are the threats currently facing the Sargasso Sea?

The greatest concern, other than the same kinds of issues that face all of us [like] climate change and the changing chemistry of the ocean through acidification, is the direct disturbances caused by shipping. You certainly upend the [seaweed] masses and all the little creatures that are there.

Storms do this too, but we're the added storm that continues to disrupt and break up these large masses.

No one's suggesting that we stop shipping through the Sargasso Sea, but the goal is to try to identify critical migration routes so we can advise ships crossing areas where whales can be encountered, or where tuna are migrating.

How were you involved in this agreement to protect the Sargasso Sea?

As a consequence of the TED Wish that I made in 2009, when I was given the TED Prize, we were given funding that made it possible for us to have a remarkable expedition to the Galápagos Islands.

One of the people on the expedition, [businessman and conservationist] David Shaw, was inspired to take this idea of working through the Bermuda government and with scientists there and elsewhere, and put together the Sargasso Sea Alliance to foster this agreement to win protection of two million square miles of it. Getting nations to agree to exercise care and to not exploit it with long-lining or stripping it [for resources].

He and a group of others on that ship got their hitch together and that's where the Sargasso Sea [Alliance] was born. I was part of the steering committee.

We now understand that more than half the oxygen that we breathe comes from the sea. It's our life-support system.

Heretofore, it was looked at as a source of goods or means of transportation, or sometimes a convenient place to conduct warfare.

[But] the most important thing we extract from the oceans is our existence. This is the moment in time, before we carve up the rest of the world to satisfy short-term interests—there is the opportunity to step back and embrace the high seas as an insurance policy if nothing else.

The agreement states that the signing countries will voluntarily take steps to conserve the Sargasso Sea. What does this mean in practice for a country like the U.S. or Bermuda?

They've agreed to promote care of the Sargasso Sea and enlist other governments to do the same. To use their power, such as it is, individually and collectively, to create this awareness of what's at stake. [The agreement] certainly can lead to binding policies. But at present, it's more a celebration of understanding that this is an area that matters.

There were a number of countries that were very interested in the concept, but there was concern that it might inhibit some of their vested interests in terms of fishing. Fishing is the biggest issue that's on the table.

Already there's significant depletion of animals in the Sargasso Sea. From turtles to whales and eels, to the most prized fish on the planet, the bluefin tuna, and other tunas as well.

What are the next steps?

What will come out of the most recent meeting in Hamilton [Bermuda's capital] is a Sargasso Sea commission. That's the next step for the process. But the steering committee, we've done our job up to this point. But I will stay engaged.

I first heard about the Sargasso Sea as a kid in Florida—I think I was 13—when reading William Beebe's book Half Mile Down. I was entranced with the idea of getting into a submersible in the Sargasso Sea. They described the most incredible creatures in the deep sea. I was hooked.

The idea that you could go down into these clear waters, down into the darkness below, and you find yourself in this magical world: It really has been responsible for provoking me to take on the ocean as my principal guiding star.

Protection for the open sea—and the Sargasso Sea in particular—protecting it right now, it doesn't cost any nation to just abstain from large-scale fishing or being smart about where you channel boats, or to be mindful of where you put the pollution.

This interview has been edited and condensed.

Follow Jane J. Lee on Twitter.

Joanne Pan
Joanne Pan

Is this article in any National Geographic Magazines? If it is, what page(s) would it be on?

Mike Barrett
Mike Barrett

Not much, I am sure w/ Mr. Fairfax's grant a scientific measurement can be undertaken.  

An alternative would be ecotourism to the area - snorkeling is all that is needed.  I have floated alongside and inside a mat while it was in the gulf stream near the Florida Keys, it was simply fascinating to see the myriad of life, tiny shrimps, crabs, juvenile fish to the giant mahi mahi and bill fishing roaming just beneath.

John Fairfax
John Fairfax

What scientific evidence exists to establish the amount of sargassum algae in the Atlantic Ocean is natural?

Pedro C
Pedro C

This is, of course, a potentially very important agreement, but the signatories are not those you list herein. 

You state "latest agreement between Bermuda, the U.S., the Azores, Monaco, and the U.K. means for the future of the Sargasso." Azores is part of Portugal, as all other entities referred in the sentence, a sovereign state. Why the discrimination?  Azores are part of Portugal's national territory, and not an independent nation. 

Similarly, Portugal is Europe's south-western extremity and they started the systematic global maritime discoveries. So, well before Columbus many a Portuguese mariner had come across the Sargasso Sea, but your ego-based sense of history appears to start with Columbus. Why do you exclude references to Portugal in this article as in most? 

Americans have a well earned fame for ignorance in geography and history, unfortunately you justify such fame herein. Furthermore, your articles do generally appear to sport a cultural/historical bias against Portugal.  I understand this is not intentional or institutional but it is clear in many of your articles, so it must be created by editors and writers alike.  

I remember how you started drawing maps that made Timor-Leste part of Indonesia soon after the territory was invaded and while they were being victims of a genocide that left half -to-one-third of the Timor population dead. Still, there you were, as here, spinning history and geography alike. Be brave, reflect a world perspective, not a biased, ignorant, p.o.v.

Is your Anglo-based ego threatened by the historical and geographical realities that would give clear preeminence to a nation of global explorers and discoveries before the Spanish, British, Dutch and all others who followed?  Yes, the British got their empire beginning from the Portuguese. I'd expect you to recognize truth in history above power in spin, not to mention in language.  Read "The First Global Village" by Martin Page, a British journalist, and educate yourself before you try to do it with your readers.

Thanks! An appreciative, yet attentive, reader.

Pedro C
Pedro C

Your editors/writers cultural bias against Portugal is amazing.  

Portugal is Europe's south-western extremity, and before Columbus many a Portuguese mariner had come across Sargasso, but you bizarrely pick your references to eliminate any reference to Portugal. 

Similarly, you state "latest agreement between Bermuda, the U.S., the Azores, Monaco, and the U.K. means for the future of the Sargasso." Azores is part of Portugal, as all other entities referred in the sentence are sovereign states. 

Why do you exclude all reference of Portugal in this article.  Are you afraid of the historical and geographical reality that gives preeminence to "the nation of the discoveries"? 

I remember how you used to draw maps that made Timor-Leste part of Indonesia soon after they invaded the territory and while they were being victims of a genocide that left close to the Timor population dead. Still, there you were, as here, spinning history while innocently discussing geography and the environment. Be brave, reflect a world perspective, not a biased fearful English pov.  Yes the British got their empire beginning from the Portuguese. I'd expect you to recognize truth in history above power in language. 

Maybe you'd have to recognize Portugal as the first global village and their global discoveries as the first truly "global" and definitely more scientific, for less mercantile(as in corporate)?  

Read "The First Global Village" by Martin Page, a British journalist, and educate your ego.

Jim Ong
Jim Ong

Creatures of this realm fated to intertwine, the life of each depends on the life of next. A ruthless and yet the most simplest of rules. Like the Ouroboros that circle its own fate, it spells the beginning of an end. The euphoria of beautiful beings comes and goes, to cherish or to be lost into the sands of time, to act now or choose to wait, one can still change thy fate today.


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