Save the Illinois River Inc. | Environment | August 29, 2024
From: Waye, Don
Sent: Friday, August 30, 2024 12:16 PM
To: NPS Information Exchange
Subject: [npsinfo] New Release: EPA's National Lakes Assessment 2022 Report
The EPA released the National Lakes Assessment: The Fourth Collaborative Survey of the Lakes in the United States, or NLA, on August 29. This report presents the results of the 2022 survey of the nation's lakes. The NLA is a statistical survey designed to provide information on chemical, biological and physical indicators of the health of our nation's lakes. Healthy lakes enhance our quality of life and provide many critical services and recreational opportunities. Results from the NLA can help us better understand the condition of lakes in the United States and some of the stressors affecting them, such as these key takeaways:
· The 2022 survey indicates that nutrient pollution is the most widespread stressor with 50% of lakes in poor condition with elevated phosphorus, and 47% in poor condition with elevated nitrogen. Excess nutrients can affect public health and recreation by contributing to eutrophication, algal and cyanobacterial blooms, and low oxygen levels.
· High levels of algal and cyanobacterial growth were observed with 30% of lakes in hypereutrophic status. These lakes have very high primary productivity, reduced biological diversity and reduced metabolism. Microcystins, a type of cyanobacterial toxin which can cause negative health effects, exceeded the EPA recreational criterion in 2% of lakes, representing 5,360 lakes across the nation.
· The herbicide atrazine was detected at low levels in 41% of lakes and exceeded the EPA benchmark, the concentration equivalent level of concern for aquatic plant communities, in 1% of lakes, representing 2,680 lakes.
· Observations of physical habitat indicate that lakeshore disturbance was widespread (84% in poor or fair condition), however, most lakes were rated good for shallow water habitat (55%), riparian (lakeshore) vegetation cover (52%) and habitat complexity (51%) conditions.
· Contaminants were present in all fish tissue, but risk varied by contaminant and by fish consumption level.
More information on the EPA’s National Aquatic Resource Surveys can be found on the NARS website. For more information on the NLA, contact Lareina Guenzel. Feel free to share this announcement with your networks.
Don Waye
U.S. EPA - Nonpoint Source Management Branch
