What Keeps Washing Ashore (Part 1: Living with Sargasso)

When we first arrived in Mahahual, the sargasso seaweed seemed almost whimsical. I loved that it made our beaches feel like you were on a secluded island. These were not the manicured beaches of the developed world. When it got heavier in the summer, I thought of it as a mild inconvenience. 5 years ago, it was light and intermittent.

Like many people living and working along the Caribbean coast, as the volumes have increased, I started to experience it as something overwhelming and difficult — mountains of seaweed arriving unpredictably, changing the shoreline, creating difficult odors as it decomposed, and constantly forcing us to adapt.

But over time, living with it began changing the way I saw it. It certainly didn't get easier to deal with. But I started realizing the sargasso itself was telling a much larger story about the condition of our oceans. I realized I really needed to learn to listen to the voice of the ocean.

The massive blooms now arriving throughout the Caribbean are linked to changing ocean temperatures, nutrient runoff, deforestation, industrial agriculture, and larger shifts happening throughout interconnected eco-systems. Oil spills in the ocean are cleaned with nitrogen - a fertilizer that has impacted sargasso blooms dramatically. The Amazon and the Mississippi are filled with fertilizer carried down from farming all throughout the Americas. The warm oceans don't allow the normal annual die-off of sargasso in the winters. So it is growing and growing and growing out there in the ocean. And it is coming to our shores.

Researchers have found that sargassum absorbs heavy metals and other pollutants from the water around it. Over time, I began wondering whether part of what we are witnessing is not simply an invasion of seaweed, but an ocean trying to process enormous amounts of imbalance and contamination moving through global systems. Sargassum is like a cleanse for the water, pulling the toxins out of the ocean and sending them back to us on shore.

And once you begin looking closely at the sargasso floating offshore, something else becomes impossible to ignore.

Plastic.

Again and again, we would see floating plastic tangled into the sargasso mats as they drifted toward shore. Bottles. Fragments. Fishing debris. Tiny broken pieces of human consumption traveling alongside this massive floating ecosystem.

At sea, sargassum is not inherently harmful. In fact, floating sargasso ecosystems provide shelter and habitat for fish, turtles, crabs, and countless marine organisms. But when unprecedented quantities wash ashore and begin decomposing on coastlines, the effects can become devastating for beaches, reefs, tourism, and coastal ecosystems.

Living with it means constantly holding both truths at once.

I began seeing sargassum as part of a much larger conversation between humanity and the ocean itself — a visible reminder that nothing we do disappears completely. Fertilizers, pollution, warming waters, plastic, deforestation, industrial systems: eventually, the consequences move somewhere.

And sometimes the sea brings them back to shore for us to confront directly.

At Mahai, we are still learning how to live with these changing realities. Winters are manageable and we are working on our "sargasso fence" which will keep it off our beach. Summers are overwhelming. The volumes are increasing dramatically. We have made the decision to close for the summer while we keep learning to navigate this new reality.

The process of adapting to sargasso has taught us something important. The natural world is not separate from us.

The ocean is responding to the way we live. We need to make sure we can live with that.