Fish Advisory for Mammoth Creek Offers Safe-Eating Advice for Trout Species

For Immediate Release 
Contact: Amy Gilson
(916) 764-0955
Amy.Gilson@oehha.ca.gov

SACRAMENTO – Today, the California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA) issued a new fish consumption advisory for Mammoth Creek, located 36 miles northwest of the city of Bishop, in Mono County. The advisory pertains to the portion of Mammoth Creek beginning at the Twin Lakes outfall, which flows under Lake Mary Rd, to where it converges with Hot Creek. The advisory provides safe-eating advice for Brown Trout and Rainbow Trout. 

OEHHA’s Good Catch California program routinely develops fish advisories so Californians can make healthy choices about the fish they catch in waterbodies across the state. 

“If you eat fish from Mammoth Creek, check our new fish advice. It can help you decide which fish to eat and how much,” said fish advisory program manager Dr. Wesley Smith. “We issued guidance for trout species to help you choose how much fish is safe to eat.”

OEHHA developed these recommendations based on the levels of mercury found in fish caught in the creek. Historic mining and coal burning released mercury into the environment, where it can accumulate in fish. Because mercury affects brain development, particularly in developing children and fetuses, OEHHA provides advice tailored to two groups based on sex and age. 

For Mammoth Creek, OEHHA provides the following safe-eating advice:

Women (18 – 49 years) and children (1 – 17 years)

• May eat the following on a weekly basis:

  • Seven total servings of Rainbow Trout, or

  • One total serving of Brown Trout.

Women (50 years and older) and men (18 years and older) 

• May eat the following on a weekly basis:

  • Seven total servings of Rainbow Trout, or

  • Two total servings of Brown Trout. 

One serving for adults is an eight-ounce fish fillet, measured before cooking, which is roughly the size and thickness of your hand. For small fish species, several individual fish may make up a single eight-ounce serving. Children should eat servings of less than eight ounces. Eating fish in amounts slightly greater than the advisory’s recommendations is not likely to cause health problems if it is done only occasionally, such as eating fish caught during an annual vacation.

A poster with safe-eating advice for Mammoth Creek is available on OEHHA’s website in both English and Spanish. For fish species found in Mammoth Creek that are not included in this advisory, OEHHA recommends following its statewide advisory for eating fish from California rivers, streams, and creeks without site-specific advice.

OEHHA’s fish advisory recommendations are based on the levels of contaminants, such as mercury, that persist in the environment and accumulate in fish. They are independent of any shorter-term advisories to limit fish intake due to freshwater or estuarine harmful algal blooms (HABs), which can produce toxins harmful to humans. Before fishing, check the California HAB Reports Map to see if there are HAB advisories and always practice healthy water habits.

OEHHA has released more than 150 advisories that provide site-specific, health-based fish consumption advice for many places where people catch and eat fish in California, including lakes, rivers, bays, reservoirs and the California coast. OEHHA’s mission is to protect and enhance the health of Californians and the environment through scientific evaluations that inform, support, and guide regulatory and other actions in the state.

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