November 2018
High Levels of Mercury in Local Fish
District 4 Newsletter
Yolo County, First 5, and the Delta Conservancy are working together to help prevent mercury poisoning by spreading awareness of how to safely consume Delta and Sacramento River fish.
New research has revealed that the Sacramento River and Delta located, partly in Yolo County, contain fish with low to high levels of mercury. Mercury is liquid at room temperature and toxic to humans. Due to some higher levels of mercury in fish, The Delta Conservancy and Yolo County are working with local agencies to spread awareness about fish consumption safety. In collaboration with Yolo County's First 5, informative materials provided by the Delta Conservancy and verbal information is being delivered to under-served children and families.
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What is known as 'Methylmercury' has seeped into the Sacramento River and Delta waters over time due to mining and other practices and has now entered the bodies of fish. This mercury 'bioaccumulates', meaning it grows in concentration in the bodies of larger fish as they eat small fish that contain lower levels of mercury. This mercury, when ingested by humans after consuming certain fish species, poses a threat to children and young women who are or could become pregnant. Others who consume a large amount of fish can also be affected.
In addition to being cautious regarding the type of fish consumed, serving sizes are also recommended so that all fish is consumed safely. An adult serving size, is the size and thickness of the palm of an adult hand, likewise, a child's serving size is the size and thickness of the palm of a child's hand.

Preparing and consuming fish is important for both culture and sustenance, however it is vital that only safe fish are eaten and that they are properly prepared. When preparing fish to be cooked, you should always remove the head and guts so that you are only consuming the fillet of the fish. This does not remove all mercury-containing parts of the fish but does remove some of the tissues that contain higher levels of mercury. It is also important to remember that just because water may look clean it may still contain fish with high levels of mercury.

Be aware that fish that are safe to consume in some areas may not be safe in all areas. For more information you can visit the Delta Conservancy website at and under the 'Programs' tab you will find 'Mercury Exposure Reduction Program (MERP)' materials and information for your area.

Special thanks to my UC Davis intern, Mariah Piepho, for her assistance on this project.