 Nutrient pollution is a widespread international problem. Nitrogen is important for aquatic plant growth and supports entire ecosystems, but too much of it can cause algae blooms and coastal dead zones. In the southeast of South Australia lies a jewel of biodiversity, supporting a very valuable fishery which has sustained its traditional owners through many, many generations. The Kurong is a coastal lagoon at the end of the mighty Murray-Darling Basin and runs over 100km in parallel with the Southern Ocean. It's also been internationally recognized as an important migratory water bird habitat. And through many years of drought and human activities upstream in the basin, it's seen a massive decrease in freshwater flow to the system. It's become very salty and faces extreme nutrient pollution. What if there was a way for tiny microbes in the dirt to help? Huge communities of microorganisms live inside this small sample. We know that some of them are able to limit the amount of nitrogen in the environment, which could help fighting nutrient pollution. Unfortunately, we don't fully understand their activity in salty conditions such as this. My current research investigates the role that rapidly changing conditions play in stressing out these communities and potentially preventing them from performing their role correctly. Our team takes core samples like this one, and we can look at the genetic code inside of here to better understand the processes and figure out how and when to use our precious freshwater resources. So what's the limit nitrogen pollution in the environment? These communities are often overlooked, and we don't fully understand their role here. This understanding is important to correctly managing this unique environment.