Mercury in Local Fish & Shellfish

In 2012, coastwide sampling across California found the highest mercury levels in the state in leopard shark from Humboldt Bay. In 2016 and 2019, Humboldt Waterkeeper received grants from the California Environmental Protection Agency to test mercury levels in fish caught by local subsistence, tribal, and sport fishermen to determine the magnitude of local mercury contamination in fish and shellfish in Humboldt Bay and nearshore coastal waters.

We used our findings to develop recommendations for Eating Fish Safely (in Spanish, see Comiendo Pescado Con Seguridad Pautas; in Hmong, see Yuav Ua Li Cas Noj Ntses Yam Xyuam Xim Cov Txhooj Cai Rau Humboldt Bay). To request multiple copies of these fliers for health clinics, community events, etc. please email This email address is being protected from spambots. You need JavaScript enabled to view it..

Eating Local Fish Safely: Humboldt Bay Mercury Assessment, Phase II

Our second study of mercury in local fish focused on nine species from nearshore coastal waters, including Pacific Halibut and several species of rockfish. We also sampled more Lingcod and California Halibut to add to the findings from our 2018 study. We found that most local fish are safe to eat in moderation—with a few exceptions.

Download our mercury fliers in English, Spanish, or Hmong:

Recommendations for Eating Local Fish Safely

Comiendo Pescado Con Seguridad Pautas

Yuav Ua Li Cas Noj Ntses Yam Xyuam Xim Cov Txhooj Cai Rau Humboldt Bay

Pocket-sized images for handy reference (click to print or download to your phone):

Women <45 and Children

Women >45 and Men

How much mercury is in your seafood?

Report: Most local fish, shellfish harmless in moderation

A new study assessing mercury accumulation in local fish and shellfish found most nearshore coastal species are safe to consume in moderation — with a few exceptions.A new study assessing mercury accumulation in local fish and shellfish found most nearshore coastal species are safe to consume in moderation — with a few exceptions.

The study, conducted by Humboldt Baykeeper between 2019 and 2020, took a look at the mercury levels in 70 individual fish across nine species including lingcod, several species of rockfish as well as Pacific and California halibut.

“This is our second study and we focused on fish caught in nearshore areas between Reading Rock and Cape Mendocino whereas our first study focused on fish caught in Humboldt Bay,” said Humboldt Baykeeper director Jennifer Kalt. “Pacific halibut was one species that a lot of the sport fishers wanted us to focus on because it’s such a popular fish, people are catching the living daylights out of it right now.”

Looking for the Safest Local Seafood to Eat, Mercury-Wise? Baykeeper Has an Updated Chart for That

Worried about the mercury content of your seafood? You should be! Mercury is a nasty heavy metal that can cause any number of serious health conditions if ingested in large enough quantity, and that’s especially true if you are a child or a woman who may be/get pregnant. Seafood is the principal way that it enters the human food chain.

But some species of fish are more dangerous than others, depending on their habitat and their place in the food chain. Over the years, Humboldt Baykeeper has conducted mercury sampling of local seafood and, after a new round of testing on the catch found of coastal waters — not just in Humboldt Bay — they’ve put out a new eater’s guide to bounty of the Humboldt seas.

Downloadable friendly versions of the charts for your phone:

Women <45 and Children
Women >45 and Men

Humboldt Baykeeper Continues Testing Fish For Mercury

Californians need to know if the fish they catch are safe to eat, so the state keeps spending money on testing fish for mercury.

Cal EPA recently awarded another grant to Humboldt Baykeeper to continue its mercury testing program, this time on some species of fish that were not the focus of previous testing.

Those earlier tests revealed that not all the fish on the North Coast are safe to eat all the time.

Jennifer Kalt is Humboldt Baykeeper's director and our guest.

Humboldt Baykeeper gets $40K to test more North Coast fish for mercury

The California Environmental Protection Agency awarded Humboldt Baykeeper, a program of the environmental conservation nonprofit Northcoast Environmental Center, $40,365 on June 26 to test Pacific lamprey, lingcod, rockfish and other fish species for mercury.

“The idea here is to get some more local information so people can base what they’re feeding themselves and their children in particular on local data instead of general data from other parts of the state,” said Jennifer Kalt, director of Humboldt Baykeeper.

A previous grant from the state EPA allowed Humboldt Baykeeper to assess the mercury content in coastal fish and shellfish and put out guidelines, which are available in English, Spanish and Hmong, regarding which ones are safest to eat.

“From that study, we had a lot of good news and bad news,” Kalt said. “Chinook Salmon are very low in mercury, so you can eat those up to 28 times per month. That’s good for tribal members because that amount is consistent with the amounts of fish they might eat.”