What Everyone’s Not Saying About Sargassum

Sargassum mats line South Padre's beach north of Clayton's Bar and Grill. Teresa Shumaker photo.

 Sargassum mats line South Padre's beach north of Clayton's Bar and Grill. Teresa Shumaker photo.

By Gladys Delgadillo
You’ve seen it on our beaches: the heaping strips of seaweed. What you’re looking at is Sargassum fluitans and natans, which is brown algae — and it stinks. Thick sargassum makes it difficult for nesting mama sea turtles to make it up the beach, for nesting patrollers to see turtle tracks, and eventually for hatchlings to make it to the ocean. Plus, it’s widely regarded as unattractive.

But what isn't being said is how great it is! When the seaweed makes its way to Texas beaches, it’s a natural phenomenon! When sargassum is in the ocean, it serves as both a shelter and a buffet for hatchlings who are not strong swimmers yet. Green sea turtles will eat large quantities of it throughout their lifetime. When the tide washes the seaweed onshore, the sargassum, and the organisms that live in it (as well as the flies it attracts), provide food for shore birds.

In addition, it serves as a buffer on the beach, reducing wave and wind erosion. It also holds down the sand in dunes, making them more resilient! Less erosion means more sand on the beaches to structurally support beachfront properties and for people to play in. Eventually, the seaweed will decompose into the sand, replenishing the shore. The nutrients from the decomposed algae act like a fertilizer, improving the growth of vegetation on the dunes. Dune plants are important natural tools to hold sand in place, both through their root structure and natural cover, preventing erosion of the beaches.

While government raking to remove sargassum is wonderful in many respects, it’s important to remember that one cannot rake the seaweed away without also removing sand. Removing both, the sand and the natural buffer that sargassum provides, intensifies the erosion problem that threatens our beaches. Hopefully, knowing this will give you some peace if you have to take a rake with you to clear a spot for your towel on a sargassum covered beach. Love it or hate it, sargassum is here invaluable resource to STI and our mission.

The tide brings it to Texas beaches from March to June. Tropical storms increase the amount of seaweed that washes ashore, and as climate change causes tropical storms to be more frequent and intense, more seaweed is expected to drift onto the shore. Having said that, we might as well start talking a little more about how sargassum is working to preserve our beaches, so we can frown a little less when we see it!

Gladys Delgadillo wrote this article when she was one of STI's 2014 interns. She is from Escondido, CA. and has a B.S. from Stanford University in Earth Systems, where she focused on how humans and environmental problems are related.