“Yellow Perch (Perca flavescens) Mercury Unaffected by Wildland Fires in Northern Minnesota” with Dr. Randy Kolka and Trent Wickman.

We often hear of the dangers of mercury to pregnant women and children that require them to restrict fish consumption. For good reason – even at low concentrations, mercury can do serious damage to neural networks and reproductive systems. However, we talk little of how the mercury gets in these fish in the first place.

The most common way mercury enters the ecosystem is through the burning of coal; however, it can also volatilize via prescribed and wild fires in forests. From there, it can redistribute into other parts of the ecosystem, such as lakes, and work its way into the food chain. This can hurt the animals that rely on lakes or the fish that live in them to survive. It can also hurt people. For Dr. Randy Kolka and Trent Wickman of the USDA Forest Service, who love the people and wildlife of Northern Minnesota – they had to know more.

They set up a study on two lakes – one that hadn’t seen a fire in over 100 years and one that had a serious fire that covered over 99% of the watershed – and sampled soil, water, and fish to compare mercury levels.

In this episode, they discuss their experimental design, along with a breakdown of the realities of fieldwork. It can be tough carrying heavy equipment or samples of lakewater, let alone camping gear and food; they discuss how they made choices on what to bring, how samples were collected, and how they managed the logistics of the trips.

Tune in to learn this and more:

• How does one collect a water sample from a deep lake?
• What’s a “crown fire” and why is it so dangerous?
• How is fire severity judged?
• Why perch?

If you would like more information about this topic, this episode’s paper is available here: https://doi.org/10.2134/jeq2016.10.0418 

It will be freely available from 19 October to 2 November, 2018.

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If you would like to reach out to Randy, you can find him here: https://www.nrs.fs.fed.us/people/Kolka [email protected]

If you would like to reach out to Trent, you can find him here: [email protected]

Resources

CEU Quiz: http://www.agronomy.org/education/classroom/classes/827 

No Mercury Accumulation in Fish after Fire: https://www.soils.org/discover-soils/story/burn-without-concern

BWCWA: https://www.fs.usda.gov/detail/superior/specialplaces/?cid=fseprd555184

Randy’s additional fire and mercury publications: https://www.nrs.fs.fed.us/people/Kolka

MN Department of Health fish consumption advisories: http://www.health.state.mn.us/divs/eh/fish/index.html

USDA Forest Service Northern Research Station: https://www.nrs.fs.fed.us/

USDA Forest Service, Air Resource Management R8 & 9: https://webcam.srs.fs.fed.us/

Field, Lab, Earth is copyrighted to the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.