Skip to main content

What's that smell? The bacteria living in the Laguna Madre

Local waters host a plethora of anaerobic bacteria.
Local waters host a plethora of anaerobic bacteria.
Larissa M. Diaz

You are driving across the bridge towards North Padre Island, anticipating a relaxing day at the beach. Your swimsuit, towel, snacks, and ice-cold beverages are just an arm's length away. On a whim, you roll down the window over the calm Laguna Madre to catch a breath of the most refreshing air of all – a faint sea breeze – when a horrible rotten-egg stench fills up your vehicle. Quickly, you roll up the window in a hasty attempt to get rid of this noisome odor.

If this has ever happened to you, you are not alone. You might have had second thoughts as to whether a trip to the beach was really a great idea, pondering whether a dead whale might have washed up on the beach or if the smell was due to toxic waste and pollution. What was really happening was a very important and natural process.

Sulfur and sulfate-oxidizing anaerobic bacteria thrive in the soils of the Laguna Madre, and play a significant role in the biogeochemical cycling of sulfur. Sulfur, in its various forms, is necessary for many living things. These stinky bacteria essentially make the sulfur available to plants, from whence it is incorporated into the tissues of the plants and other organisms that consume plants, becoming part of the food chain. Without these bacteria, there would be way too many sulfur compounds that are not usable to organisms, and not enough available forms of sulfur in the soil. The smell is caused by the sulfur compounds that are produced, which smell like rotten eggs.