Building a Beach from Seaweed (Part 2: Living with Sargasso)

When I experienced my first serious sargasso summer in Mahahual, I was focused on removing the seaweed as quickly as possible, not just from the beach but from our property all together. As a cyclical summer event, we don't really have any guests when the sargasso is at its worst, but we were still determined to get it off the beach as quickly as possible.

Like many people living along the Caribbean, our team spent countless hours hauling seaweed under the hot sun, trying to keep pathways clear and reduce the smell and decay that happen when massive quantities pile up and begin decomposing.

I started noticing that the areas on my neighbors' properties where sargasso remained wet and compacted directly against the shoreline often seemed to accelerate erosion. In some places nearby where they didn't have a stretch of flat beach, we watched the property begin disappearing into the ocean alarmingly fast. Sand and soil would collapse right into the sea. We saw trees fall down, even our neighbor's front porch fell right off the house into the ocean. The coastline felt like it was weakening.

At the same time, I began noticing that where sargasso mixed with sand on the beach, and then dried out, it stabilized differently. Something else started happening.

The beach itself began changing.

Our property lies between two very different topographies. On one side, we had a disappearing cliff of land. On the other side, a flat beach with drying sargasso piling up on it.

We decided to experiment.

Parts of our beach were very rocky. We used those rocks as barriers. Instead of treating all the sargasso as waste, we began layering large quantities of it behind the rock barriers. Once it had dried, we buried the sargasso layers in the sand.

At first, it looked rough and improvised.

But slowly, over time, the shoreline began building upward instead of disappearing. We even started asking some of our neighbors for their sargasso and adding it to our beach.

The beach became solid and the erosion stopped.

What was amazing was that the composting sargasso began creating richer organic material within what had previously been mostly nutrient-poor sand. Plants and vines started growing in areas that had once remained bare. The piles we created slowly began turning into small dunes. Root systems spread through them naturally, helping stabilize sections of beach that had been washing away before.

Without entirely intending to, we found ourselves participating in a kind of coastal succession process. The beach was adapting.

The longer I live here, the more I realize how much modern life trained me to think in terms of removal and disposal. Something appears that I don’t want, and the instinct is immediately: How do I get rid of it?

But nature often works differently.

My lesson over and over again here is that nothing truly disappears. We are in the midst of nature's true nature, which is to create balance. Materials transform. Systems adapt. One thing becomes the foundation for something else.

Over time, I have tried to stop seeing the sargasso only as an invader washing onto shore and start trying to understand its purpose as part of a changing ecological system that we are all struggling to understand.

The struggle is real. But I know that nature has her way of finding balance. I believe sargasso itself is truly part of her balancing act.

Sargasso is still totally overwhelming. During heavy seasons, the labor is relentless. The smell can become intense. The decomposition damages shorelines and marine ecosystems when massive quantities accumulate. Living with it is not romantic.

But it also became impossible for me to ignore that life itself was beginning to emerge from the very material we initially viewed only as destruction.

Recently, Victor Rosales, who is a local environmentalist in Mahahual, explained something to me that added yet another layer of complexity to all of this.

One of the reasons so many plants are now growing on previously clear sandy beaches is because the decomposing sargasso is enriching the sand itself with nutrients. In many places along the coast, vegetation is beginning to spread much more densely than before. My immediate response was that this is a good thing. Plants help stabilize the beaches and slow erosion.

But Victor explained that this may also be creating challenges for sea turtles.

Historically, turtles nested on clearer sandy beaches. Dense vines and vegetation can make nesting more difficult for the turtles.

Once again , I am reminded that ecosystems are never static. Every shift creates another set of consequences, pressures, and adaptations. The coastline itself is evolving in response to warming waters, nutrient runoff, erosion, storms, changing currents, and the enormous influxes of sargasso arriving each year.

Nature keeps searching for balance.

But balance does not necessarily mean returning to what existed before.

Living here is teaching me that stewardship is often less about controlling nature and more about learning to observe carefully, adapt thoughtfully, and remain humble in the face of systems far more complex than we fully understand.

And sometimes, unexpectedly, even a mountain of seaweed can become the beginning of new life. I'm so grateful that the seasons change and as autumn arrives up north, the sargasso gives us a much needed respite to enjoy the lush greenery it feeds.