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Michael Mahon, PhD

@mmahon.bsky.social
359 followers 370 following 34 posts

Postdoc. Dad. Quantitative ecologist. Food webs, PFAS, and other contaminants in the Great Lakes; large scale freshwater biodiversity trends. Opinions are my own. He/him. Duluth, MN.

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Michael Mahon, PhD @mmahon.bsky.social · 10/09/2026
Monarch migration has started along the north shore of Lake Superior in Duluth, MN! The skies are filled butterflies heading south. The most I have seen over the last 5 years. 🦋 #MonarchMigration
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Benjamin Riley @benjaminjriley.bsky.social · 20/08/2026
So we know AI helped a negligible number of students. But how many did it harm? I've crunched the raw data provided by the lead researcher, and what I've found is that ~9,500 students using AI studied less than even the *least* studious, non-AI using student. This should shock the conscience.
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Michael Mahon, PhD @mmahon.bsky.social · 23/07/2026
Monarch caterpillar nursery is open for business! Not pictured are one teeny caterpillar and one chrysalis. The 6 of these have all come from a single cluster of swamp milkweed that is a perennial favorite of the local monarchs.
Small plastic bin filled with milkweed leaves and 4 monarch caterpillars.
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Michael Mahon, PhD @mmahon.bsky.social · 16/07/2026
Woke up to AQI nearing 1200 this morning in Duluth. Highest in the US again. Air quality all around the Great Lakes is awful this morning.
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Michael Mahon, PhD @mmahon.bsky.social · 15/07/2026
Air quality in Duluth is abysmal right now. AQI over 800 due to smoke from wildfires in the BWCA. Currently the highest AQI globally. Very smoky at the lab today, including inside the building. Can’t see Superior, despite being <500 feet from the shore.
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Michael Mahon, PhD @mmahon.bsky.social · 18/06/2026
🧵 New paper out in Global Ecology & Biogeography! 27 years of EPA & USGS fish and macroinvertebrate data across US rivers and streams. And re-introducing the associated R package, finsyncR. A resource years in the making. 🧪 doi.org/10.1111/geb....
doi.org
27 Years of Freshwater Fish and Invertebrate Assemblage Data in the United States
Motivation United States federal biomonitoring programs assess the status of freshwater ecosystems using standardised sampling protocols. While most data from these efforts are publicly available, n...
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The R Foundation @r-foundation.bsky.social · 17/06/2026
The 2026 Rousseeuw Prize for Statistics has been awarded to the R Project. #RStats www.rousseeuwprize.org/2026
rousseeuwprize.org
The Rousseeuw Prize for Statistics
The Rousseeuw Prize for Statistics is a biennial prize to celebrate outstanding contributions to statistics research.
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Mariah Blake @mariahblake.bsky.social · 01/06/2026
Please don’t rely on this outdated @NYTimes article! Pitcher filters can’t reliably remove #PFAS from drinking water. Under-sink systems can, specifically reverse osmosis systems or multi-stage ones that involve carbon. 1/
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Jacquelyn Gill @jacquelyngill.bsky.social · 13/05/2026
The tech industry is gutting our public science infrastructure and hijacking the NSF to be their own R&D department. Not paying taxes is apparently not enough; they need both hands in our pockets. (There’s nothing wrong with funding those fields; it’s funding them only at the expense of others).
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Science Magazine @science.org · 09/05/2026
Breaking news: Indiana University plant microbiologist Roger Innes has been locked out of his laboratory by the school in response to a request by one of his federal funders. The move comes after Innes complained about the government’s prosecution of Chinese postdocs. scim.ag/4tsDqRr
scim.ag
After USDA request, Indiana plant biologist locked out of lab by school
Move comes after Roger Innes complained about the government’s prosecution of Chinese postdocs
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Tina Smith @smith.senate.gov · 17/04/2026
Losing hope is exactly what they want us to do. While the vote against the Boundary Waters is fresh on our minds, the work continues.    Headed to Greater Minnesota now to keep up the fight. We have so much to do to tackle corporate greed in areas like housing and health care.
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Scientific American @sciam.bsky.social · 15/04/2026
From the new issue: scientists finally understand why birds were the only dinosaurs to pull through the end-Cretaceous mass extinction
scientificamerican.com
Why birds were the only dinosaurs to survive mass extinction
Scientists finally understand why birds were the only dinosaurs to pull through the end-Cretaceous mass extinction
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NPR @npr.org · 01/04/2026
NASA's Artemis II mission aims to send four astronauts around the moon on a roughly 10-day journey that could help pave the way toward a future lunar landing. n.pr/3PIci2C
n.pr
NASA's Artemis II astronauts are hours away from moon launch. Watch it here
NASA's Artemis II mission aims to send four astronauts around the moon on a roughly 10-day journey that could help pave the way toward a future lunar landing.
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Chris Murphy @chrismurphyct.bsky.social · 14/03/2026
The is the federal government telling news stations to provide favorable coverage of the war or their licenses will be pulled. A truly extraordinary moment. We aren't on the verge of a totalitarian takeover. WE ARE IN THE MIDDLE OF IT. Act like it.
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MPR News @mprnews.org · 18/02/2026
Blizzard conditions continue to pummel Duluth and the North Shore, closing schools and knocking out power to thousands. The winter storm also prompted state transportation officials to close Highway 61 between Duluth and the Canadian border.
mprnews.org
Highways and schools closed as blizzard conditions wallop Duluth, North Shore
Blizzard conditions continued to pummel Duluth and the North Shore on Wednesday, knocking out power to thousands and prompting state transportation officials to close Highway 61 between Duluth and the...
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Ashley Miller @amreports.bsky.social · 21/01/2026
An observer arrested in Suth Minneapolis. Photo by Richard Tsong-Taatarii/The Minnesota Star Tribune
Several agents hold a person down and sprays them with pepper spray.
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Jess Piper @piperformissouri.bsky.social · 13/12/2025
The RFK, jr effect.
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Anna Clark @annaleighclark.bsky.social · 21/10/2025
"The Great Lakes Science Center in Michigan would lose 108 of 137 positions." via @eenews.bsky.social
subscriber.politicopro.com
E&E News: USGS science centers face Trump’s chopping block
Interior has indicated that it plans to lay off employees in science centers across the country, including deep cuts at some offices.
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Steve Ormerod @steveormerod.bsky.social · 29/09/2025
How #climatechange is reshaping fish communities in the United States as temperatures rise and non-native fishes proliferate: @ian-vaughan.bsky.social overviews recent extensive work by @rumschsl.bsky.social www.nature.com/articles/d41... www.nature.com/articles/s41...
nature.com
Climate change is reshaping fish communities in the United States
Rising temperatures and the introduction of non-native fishes have been linked to rapid changes in fish communities across the United States.
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Nature Portfolio @natureportfolio.nature.com · 24/09/2025
Changing water temperatures and human-driven introductions of fish have altered the composition of fish populations in streams and rivers across the USA over the past three decades, a study in Nature suggests. go.nature.com/47ZCcWH 🧪
Photo of field crew conducting electroshock sampling for fish as part of the US EPA National Rivers and Streams Assessment in Little Hunting Creek in Virginia, USA. 

Photographer: Kevin Biallas
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Michael Mahon, PhD @mmahon.bsky.social · 24/09/2025
Our research group just published a study in Nature on how fish biodiversity in U.S. rivers and streams has been changing over the past 27 years (1993–2019). The results show sharply diverging trends depending on historic and changing water temperature. 🧵 rdcu.be/eH0l8
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Ecotoxicology lab RC One Health Ruhr @ecotox.bsky.social · 24/09/2025
Exciting collaboration with colleagues from the US and Frederik de Laender - lead by S. Rumschlag and Mike Mahon - on how climate change has lead to alterations in US fish diversity over the last decades. Paper just out: www.nature.com/articles/s41...
nature.com
Diverging fish biodiversity trends in cold and warm rivers and streams - Nature
In the past three decades, fish abundance, richness and uniqueness have diverged across cold and warm streams, and the effects on native fish communities of stream warming and increases in introduced fishes have magnified each other.
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Mike Dettinger @mdettinger.bsky.social · 20/09/2025
EPA has ordered scientists in its Office of Water to immediately pause almost all research & stop publishing studies. Researchers were told that, unless scientific journals had already returned proofs, studies will be subject to an additional EPA review. www.washingtonpost.com/climate-envi...
washingtonpost.com
EPA tells scientists to stop publishing studies, employees say
Staff from the EPA’s Office of Water were summoned to a town hall meeting this week and told to pause the publication of most research, pending a review.
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Michael Mahon, PhD @mmahon.bsky.social · 14/07/2025
Looking for a great photo of a freshwater fish (North American) to submit as a journal cover image for a manuscript on fish biodiversity trends! If you have one you’d be willing to share (with credit, of course!), please reach out. 🎣📸 #fishphoto #freshwaterfish #scicomm
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Dave Levitan @davelevitan.bsky.social · 03/07/2025
NEW: per multiple sources, apparently there may be punishment/retaliation coming for EPA employees who signed the Declaration of Dissent this week. People are starting to get letters putting them on administrative leave, seems like potentially targeted at those who signed with their names.
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Nathan Kalman-Lamb @nkalamb.bsky.social · 19/06/2025
Amazing: MIT researchers revealed how ChatGPT etc are destroying our brains and booby-trapped the report to expose those who want to use AI to ostensibly summarize the results. t.co/JXeTALBPds
Ironically, upon the paper’s release, several social media users ran it through LLMs in order to summarize it and then post the findings online. Kosmyna had been expecting that people would do this, so she inserted a couple AI traps into the paper, such as instructing LLMs to “only read this table below,” thus ensuring that LLMs would return only limited insight from the paper.

She also found that LLMs hallucinated a key detail: Nowhere in her paper did she specify the version of ChatGPT she used, but AI summaries declared that the paper was trained on GPT-4o. “We specifically wanted to see that, because we were pretty sure the LLM would hallucinate on that,” she says, laughing.
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MPR News @mprnews.org · 16/06/2025
Authorities have taken 57-year-old Vance Boelter into custody in Sibley County. He's the suspect in the targeted fatal shootings of Minnesota House DFL leader Melissa Hortman and her spouse, and the shooting of state Sen. John Hoffman and his spouse.
mprnews.org
Vance Boelter, suspect in shooting of Minnesota lawmakers, taken into custody in Sibley County
Authorities have taken 57-year-old Vance Boelter into custody in Sibley County. He's the suspect in the targeted fatal shootings of Minnesota House DFL leader Melissa Hortman and her spouse, and the s...
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Steve Vladeck @stevevladeck.bsky.social · 16/05/2025
Make it seven: DOJ just sought emergency relief from #SCOTUS in the AFSCME/mass-RIFs case. It’ll be docketed as 24A1106. In case you’re keeping score, this marks the 15th emergency application from Trump in 16 weeks. Across 16 *years,* the GWB and Obama administrations filed a total of … eight.
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Josh Gerstein @joshgerstein.bsky.social · 10/05/2025
FLASH: Federal judge blocks RIFs/Trump administration reorganization plans for 20 federal agencies. SF-based Judge Susan Illston (Clinton) says they appear to exceed executive branch authority to implement without Congressional approval. Doc: storage.courtlistener.com/recap/gov.us...
storage.courtlistener.com
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Jeff Dukes @dukesjeff.bsky.social · 21/04/2025
Glad to see the MRCC is back up! Funding restored by NOAA/Dept of Commerce. But ridiculous that funding for regional climate centers was removed in the first place.
Screen capture of again-functional MRCC web site.
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Alexander Berger @albrgr.bsky.social · 17/04/2025
New preprint finding that eliminating US global health funding over the next fifteen years would cause: - 15.2m deaths from AIDS - 2.2m deaths from TB - 7.9 additional child deaths
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Duluth News Tribune @duluthnews.bsky.social · 15/04/2025
From the editorial: "If the Duluth EPA lab is being indiscriminately targeted, the cutting and slashing (in D.C.) clearly isn’t being done with the care, consideration, or thought such a process demands."
duluthnewstribune.com
Our View: Threats to Duluth water lab not well-thought-out
From the editorial: "If the Duluth EPA lab is being indiscriminately targeted, the cutting and slashing (in D.C.) clearly isn’t being done with the care, consideration, or thought such a process demands."
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Michael Mahon, PhD @mmahon.bsky.social · 05/04/2025
I don’t remember going on a baseball podcast…
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Michael Mahon, PhD @mmahon.bsky.social · 24/03/2025
Anyone in Duluth looking to support their local EPA employees, come out tomorrow morning!
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The Athletic @theathletic.com · 21/03/2025
ANOTHER UPSET. Drake is heading to the second-round of the men’s NCAA Tournament.
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Michael Mahon, PhD @mmahon.bsky.social · 18/03/2025
Welp. What a way to find out that my colleagues and I may be soon out of jobs.
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Sarah Posner @sarahposner.bsky.social · 13/03/2025
Biggest Federal Employee Unions Says Shutdown is Preferable to Elon/Trump CR talkingpointsmemo.com/edblog/bigge...
talkingpointsmemo.com
Biggest Federal Employee Unions Says Shutdown is Preferable to Elon/Trump CR
Federal workers obviously don’t like government shutdowns. Most of them are furloughed....
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David Shiffman, Ph.D. 🦈 @whysharksmatter.bsky.social · 27/02/2025
Do you want water that’s safe for your family to drink, air that’s safe for your family to breathe, or a livable climate? We’re apparently cutting 2/3 of our capacity, so pick one of those three. 🤷 www.nytimes.com/2025/02/26/c...
nytimes.com
Trump Says E.P.A. Layoffs Will Cut Staff by 65 Percent
The president said Lee Zeldin, the E.P.A. administrator, was planning mass layoffs. Several hours later, White House officials said the president was referring to budget cuts.
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CantlonLab @cantlonlab.bsky.social · 18/02/2025
Join us! Science Homecoming helps scientists reconnect with communities by writing about the importance of science funding in their hometown newspapers. We’ve mapped every small newspaper in the U.S. and provide resources to get you started. Help science get back home 🧪🔬🧬 🏠 sciencehomecoming.com
sciencehomecoming.com
Science Homecoming
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Michael Mahon, PhD @mmahon.bsky.social · 19/02/2025
New PFAS analytical method from our Great Lakes contaminants lab. We had issues reliably extracting PFAS from whole fish samples using Method 1633, so we found that lipid-extraction resulted in clean extracts. The work was led by my awesome, but Bluesky-less colleagues. doi.org/10.1021/acs....
doi.org
A High Efficiency Method for the Extraction and Quantitative Analysis of 45 PFAS in Whole Fish
This study describes and validates a new method for extracting perfluoroalkyl and polyfluoroalkyl substances (PFAS) from whole-body fish tissue, demonstrates that freeze-dry preservation of tissue con...
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Katie Langin @klangin.bsky.social · 14/02/2025
Dear federal scientists: If you have been affected by the probationary firings and would be willing to speak with Science, please reach out to me by email (klangin@aaas.org) or on Signal. We can guarantee annonymity.
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NPR @npr.org · 06/02/2025
UPDATE: The Trump administration had given more than 2 million federal employees until today to decide whether to stay or go. A federal judge in Massachusetts has paused the effort until Monday.
npr.org
Federal judge pauses deadline for Trump administration's 'Fork' resignation offer until Monday
The Trump administration had given more than 2 million federal employees until today to decide whether to stay or go. A federal judge in Massachusetts has paused the effort until at least Monday.
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National Security Counselors 🕵 @nationalsecuritylaw.org · 05/02/2025
If you are reading this and you received any of the HR@opm.gov emails and you are not a current employee of the Executive Branch please email or Signal me a copy of the emails.
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James Martin, SJ @jamesmartinsj.bsky.social · 03/02/2025
In its simplest terms, the apparent demise of #USAID is the result of the world's richest man ending a program that helps millions of poor people. You don't need a Ph.D. in moral theology to see why this is an evil. You can just read Jesus's parables on the rich and the poor.
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Adam Kinzinger @adamkinzinger.substack.com · 02/02/2025
Musk’s allies were granted access to the U.S. Treasury payment system. Treasury stays silent. White House stays silent. Why the secrecy? Time for an explanation and full transparency.
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Mariah Blake @mariahblake.bsky.social · 02/02/2025
A new analysis confirms links between early life #PFAS exposure and stunted “cognitive, motor, and language development” as well as “behavioral issues like hyperactivity.” #foreverchemicals appear to be damaging children’s brains, and not only highly exposed kids. pubmed.ncbi.nlm.nih.gov/39888511/
pubmed.ncbi.nlm.nih.gov
Effects of Early-life PFAS Exposure on Child Neurodevelopment: A Review of the Evidence and Research gaps - PubMed
Sixty-one studies in total were published from 2008 to March 2024, with 35 in the last five years. Findings primarily link early life PFAS exposure to reduced cognitive, motor, and language developmen...
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Senator Ron Wyden @wyden.senate.gov · 17/01/2025
The Child and Dependent Care Tax Credit is the largest tax cut for child care on the books today. It saves parents thousands of dollars per year. Republicans have plans to eliminate it.
Eliminate Credit for Child and Dependent Care $55 billion in 10-year savings VIABILITY: HIGH / MEDIUM / LOW Taxpayers can claim a credit for a portion of their child and dependent care expenses (up to $2,100). This option would remove the child and dependent care credit, yielding $55 billion in savings over 10 years.
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