I made an app to compare mercury levels in fish

Just for fun, this weekend I threw together an app that lets you explore mercury concentrations in California fish:

fishtox.com

• Visualize how fish size impacts mercury concentrations
• Compare two or more species
• Filter the data by zooming the map

Your selection and zoom are stored in the URL, so if you come up with an interesting view you can just share the URL. Here are lingcod samples from near the Bay Area: https://fishtox.com/?bounds=39.325799%2C35.844535%2C-120.058594%2C-125.903320&species=Lingcod

Don't eat fish from Guadalupe Reservoir in the South Bay! It's near the old Almaden quicksilver mine.

https://fishtox.com/?bounds=37.203535%2C37.176184%2C-121.854601%2C-121.900263&species=Rainbow+Trout

You can eat three or four times as much black rockfish as you can copper rockfish for the same dose.

https://fishtox.com/?bounds=45.243953%2C31.541090%2C-110.917969%2C-134.296875&species=Black+Rockfish%2CCopper+Rockfish

thats really cool, and scary too

Wow, Lake Crowley rainbow trout are looking extra dense on the chart.

Nicely done

Bookmarked! Very cool. May I ask how you obtained the data? How were the fish tested? Was this just for fun, or part of your line of work?

Bookmarked! Very cool. May I ask how you obtained the data? How were the fish tested? Was this just for fun, or part of your line of work?

Yeah, I need to add some explanation and notes to the app. The data came from CEDEN, the California environmental data exchange network. I basically downloaded all the mercury data then filtered it for wet weight measurements on species of interest.

That source has good data for most of the species we catch, but frustratingly no data on pelagics, so let me know if you are aware of good data sources for things like bluefin and yellowtail.

Would you be able to add data re. other contaminants? Thinking about PCB, Dioxins, etc.

Thanks for the efforts KPD.

My only suggestion, if possible, would be for mussels. Love harvesting them. It probably doesn't fall under mercury stats but any info on contaminants would be appreciated if possible. Of course, there is always the hotline offered for when harvesting is suitable.

Thanks for the useful app. Black and Blue RF are pretty low. Crappie don’t seem to be size-dependent.

This is great. Thanks KPD.

Extremely useful!  I have keeping an eye for mercury levels.  Thanks!!!

Love this. Thanks

Would you be able to add data re. other contaminants? Thinking about PCB, Dioxins, etc.

If you ignore everything except mercury, most California advisories won’t change. The places that do change are almost all urban bays/harbors. If you eat a lot of fish from SF Bay (still predominantly mercury but some PCB concern) here are the official advisories.

Also note that they are working on advisories for PFAS, but haven't released them.

I might look at including other contaminants, but presenting all the data in a way that is still simple and easy to interpret would be a challenge.