As an organization, we have always focused on enacting change on a local level. We are here to protect Richland Creek, and its watershed; this can seem like an issue that is based solely in Nashville, but it is in fact widespread. It is important to remember that our impacts on local watersheds have lasting ramifications beyond our communities. Those of us living in a watershed are the only ones who can make it better; it is on us to change our behaviors and understanding.
Loss of Dissolved Oxygen
A new report that was published by the International Union for the Conservation of Nature following the 2019 United Nations Framework Convention on Climate Change (or COP25) found that dissolved oxygen in world’s oceans has dropped by nearly 2% in the last 50 years. Dissolved oxygen is vital to the ocean’s functions and marine life, and even a seemingly incremental change of 2% has profound and devastating impacts on the planet as a whole. The ocean is an important part of planetary cycling of elements like nitrogen and phosphorous, which are essential to life on earth. As dissolved oxygen in the ocean decreases, these cycles will be interrupted, resulting in catastrophic consequences worldwide. As Dr. Dan Laffoley, the editor of the report, puts it: “we lower these oxygen levels at our peril.” (Kendra-Louis, NYT)
There are two main contributing factors to this loss of dissolved oxygen: climate change and direct human activity. The most impactful human activity is nitrogen and phosphorous runoff, which is brought into the ocean through watersheds. A watershed is the land area that drains water into our waterways. Water is a dynamic force that interacts with the land around it, and how that land is used affects not just local water quality, but that of the entire planet. When humans use fertilizer on our farms and lawns, the excess runs off and enters our waterways. This runoff joins larger streams and rivers, and eventually flows into the ocean. Once these excess nutrients enter the ocean, they cause massive algae blooms, which quickly grow and then just as quickly die. As the algae dies, it is decomposed by bacteria, which uses up the dissolved oxygen as part of the decomposition process. In a normal, balanced system, the rate of algal death and decomposition is slow enough that the oxygen used by tbe bacteria can be replaced. When massive, runoff-induced blooms happen, however, decomposition occurs on such a scale that the water is stripped of dissolved oxygen. This in turn causes other marine life such as fish to die, and disrupts nutrient cycles that are vital to the function of our planet.
The Good News is…Each and Every One of Us Can Make it Better!
One important change we can make is to use natural fertilizer such as compost or other organic products instead of purchasing and using chemical nitrogen or phosphorous fertilizers. Remember, if you do use these chemical products more is not better; plants can only absorb so much nitrogen or phosphorous at a time. The rest is wasted and flushed into our waters, and eventully the ocean!
In order to save our oceans, we need to develop a universal understanding of how a watershed functions and how our behaviors can have a lasting impact (negative or positive!) on our waters here and worldwide. This necessity led RCWA to create the WE Story, a watershed education tool designed to teach about our watersheds and how we are part of then. We can change our behaviors to save our local waterways and our planet! To learn more, please visit richlandcreek.org/we/, or come to one of our WE Story presentations! Check richlandcreek.org/events to see our upcoming events, including WE Story presentations and volunteer opportunities.
Actions You Can Take At Home
- Use natural fertilizers!
- Make compost at home, instead of using chemical fertilizers
- If you choose to use chemical fertizers, please only dispense the recommended amount!
- Catch runoff with a rain garden or permeable pavers
- Learn about watersheds!
Sources & Additional Reading
- Pierre-Louis, Kendra. “World’s Oceans Are Losing Oxygen Rapidly, Study Finds.” The New York Times, December 7, 2019. https://www.nytimes.com/2019/12/07/climate/ocean-acidification-climate-change.html
- Harvey, Fiona. “Oceans Losing Oxygen at Unprecedented Rate, Experts Warn.” The Guardian, December 7, 2019. https://www.theguardian.com/environment/2019/dec/07/oceans-losing-oxygen-at-unprecedented-rate-experts-warn
- “Ocean Deoxygenation.” IUCN. International Union for the Conservation of Nature, December 7, 2019. https://www.iucn.org/resources/issues-briefs/ocean-deoxygenation
By Katin Liphart