Nutrients are an important component to life and play an important role in the food web. Nutrients naturally increase in an ecosystem as organic materials break down. Plants cannot grow without nutrients. However, just as over-fertilizing your lawn or garden can cause problems, excessive nutrients become detrimental to aquatic environments.
Nutrient pollution is caused when excess nutrients, such as nitrogen and phosphorus, are introduced into aquatic ecosystems. These excess nutrients drive a process called eutrophication. Excess nitrogen and/ or phosphorus can lead to increased production of algae, resulting in algal blooms. At the very least, algal blooms can block out the sun to aquatic plants, slowing down plant growth. Over production of algae can also cause swings in pH, which describes how acidic or basic the liquid is. If algal blooms become severe, aquatic plants cannot perform photosynthesis, which can cause dissolved oxygen levels drop to the point of causing fish and other aquatic life to die. Different types of algae can produce toxins that are harmful to aquatic life, humans and pets.
Sources of excess nutrients can include wastewater and run-off from farm fields and lawns. Nutrient pollution has impacted our waterways for the past several decades, resulting in serious environmental and human health issues and impacting the economy. Missouri currently has a total of 96 streams/ rivers, encompassing about 1,167 miles, impaired by nutrients or low dissolved oxygen (typically related to nutrients). It also has 107 lakes/ reservoirs, encompassing about 242,339 acres, impaired by nutrients. Nutrient pollution is a widespread, costly and challenging environmental problem. Excessive algae in sources of drinking water can cause increased costs for treatment, taste and odor issues, as well as disinfection byproducts.
Missouri has water quality standards, which are defined in Code of State Regulations 10 CSR 20-7.031, for nutrients and chlorophyll in lakes for protecting aquatic life. The standards are specific to nitrogen, phosphorus and chlorophyll-a. Chlorophyll-a is a photosynthetic pigment used by plants. Measuring chlorophyll-a is a fairly accurate way to measure how much algae growth is occurring in the water. These standards are set to protect aquatic life from the effects of eutrophication.
Additional Information:
- Algal Blooms
- Basic Information on Nutrient Pollution - EPA
- Low Dissolved Oxygen
- Nutrient Loss Reduction Strategy
- Nutrient Pollution - EPA video
- Nutrient Reduction by Wastewater Treatment Optimization
- Reduce Runoff: Slow It Down, Spread It Out, Soak It In - EPA video
- What is Nutrient Pollution? - NOAA
- What You Can Do: In Your Yard - EPA
- Water Quality Standards