Titus Seilheimer
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drfishsg.bsky.social
Titus Seilheimer
@drfishsg.bsky.social
2.8K followers 2K following 2.3K posts
Aquatic ecology & Fisheries with Wisconsin Sea Grant. Science Communication. Helping improve the Great Lakes since 2001. #Freshwater, #Fish, #GreatLakes! He/Him. Manitowoc, WI go.wisc.edu/j0c989
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drfishsg.bsky.social
Titus Seilheimer @drfishsg.bsky.social · Nov 8
Welcome new Bluesky folks!

I'm Titus, an aquatic ecologist and fisheries specialist with Wisconsin Sea Grant. I work on all things #GreatLakes and freshwater from teaching 6th graders on a beach, surveying fish in a coastal wetland, or getting seasick on a commercial fishing boat!
🧪
Bearded old guy in a canoe (he looks tired) with a big handful freshly harvested wild rice. Headshot (yikes) of male with graying beard, it was once all reddish, and a receding hairline but he's smiling because he is in a Great Lakes coastal wetland! Man in waders with a sledgehammer. Is that the Dr Fish mobile? Sure it. A red and black checked flannel? Seriously? Looks like he's ready to install a sucker monitoring station in Silver Creek, Manitowoc, WI. Live cooking demo? Why not, this is what you trained for as a scientist! The chefs show off their dishes, a smoked salmon candy salad on the left from the bearded guy and some sizzling salmon in a pan from colleague Sharon Moen. The chefs look very stylish in their Eat Wisconsin Fish aprons! Check out eatwisconsinfish.org
drfishsg.bsky.social
You need to know how to do two things to be a successful mid-career fisheries scientist:

1. Skim and delete emails

2. Dual-factor Authentication

Know about fish? That's a bonus!
November 10, 2025 at 3:34 PM
drfishsg.bsky.social
Combining the life cycle theme for #sundayfishsketch h with #GarWeek for a quick ink sketch of the Alligator Gar life cycle. Eggs -> larval -> juvenile -> adult -> back to eggs!

Don't eat those eggs!
Ink sketch of alligator gar life cycle from egg to adult and back again.
November 10, 2025 at 3:01 AM
drfishsg.bsky.social
Find a person who looks at you the way @solomonrdavid.bsky.social looks at gar!

#GarWeek

www.youtube.com/watch?v=Nw84...
Why Gars Deserve a Week of Their Own | Great Lakes Now
YouTube video by Great Lakes Now
www.youtube.com
November 7, 2025 at 5:14 PM
Reposted by Titus Seilheimer
greatlakesnow.bsky.social
It's #GarWeek! Celebrate these living fossils by learning all about what makes this freshwater species known as "trash fish" so special in our latest conversation with @solomonrdavid.bsky.social.

www.youtube.com/watch?v=Nw84...
Why Gars Deserve a Week of Their Own | Great Lakes Now
YouTube video by Great Lakes Now
www.youtube.com
November 7, 2025 at 5:08 PM
Reposted by Titus Seilheimer
pjflood.bsky.social
✨🏠 7/ The take home? When specific climate metrics and fish age are taken into account, clearer patterns emerge for predicting long-term changes. This research can help ecologists, natural resource managers, and policymakers plan for the future.
November 5, 2025 at 5:14 PM
Reposted by Titus Seilheimer
pjflood.bsky.social
1/ New research from our group @umich.edu in collaboration with MI DNR investigated if climate change is altering fish body size. Our team analyzed data from 13 species and 1,497 lakes from 1945-2020.

🐟 🧪 🌎🌐🌱
#climatescience #umichresearch
#blueskyscience

onlinelibrary.wiley.com/doi/10.1111/...
Long‐Term and Regional‐Scale Data Reveal Divergent Trends of Different Climate Variables on Fish Body Size Over 75 Years
This research demonstrated that over the past 75 years many ages of multiple species of freshwater fishes were decreasing in length through time and with increasing water temperatures. The largest de...
onlinelibrary.wiley.com
November 5, 2025 at 5:14 PM
Reposted by Titus Seilheimer
plosbiology.org
Oxygen limitation is considered a key mechanism of #ThermalTolerance. @dianasmadeira.bsky.social explores how a @plosbiology.org study challenges this idea, showing minimal protective effects of O2 supersaturation in heat-stressed #aquatic #ectotherms 🧪 Paper: plos.io/43hzMQa Primer: plos.io/3XeUtbS
The effects of temperature on organismal performance are depicted using thermal performance curves, where performance is greatest at the optimal temperature and starts to decrease toward cooler or warmer temperatures, reflecting the thermal window (tolerable range of temperatures) of the species. Briefly, the Oxygen and Capacity Limited Thermal Tolerance hypothesis proposes that oxygen limitation explains the performance decline at high temperatures and sets the first boundary for thermal limits across ectotherms. This is due to a mismatch between the oxygen demand of the organism and the capacity of the cardiorespiratory system to supply oxygen to tissues when the organism is under warming. This concept is central to predict species responses to warming. As oxygen supersaturation in water has been shown to alleviate oxygen supply limitations by increasing maximum rates of oxygen transport in blood, Raby and colleagues (2025) tested the effects of oxygen supersaturation on thermal tolerance across 14 aquatic species. The authors found that it had negligible effects on upper thermal limits, challenging the oxygen limitation hypothesis as a universal mechanism underpinning thermal tolerance of aquatic ectotherms. The authors highlight that oxygen supersaturation in water, a naturally occurring phenomenon in shallow waters, may not protect aquatic species from the effects of extreme heat.
November 6, 2025 at 5:30 PM
drfishsg.bsky.social
Sharks and Shark Cages
November 7, 2025 at 1:26 PM
drfishsg.bsky.social
Interested in the fish and fisheries of the #GreatLakes? Why not check out the Great Lakes Heritage Trail website and resources.

www.greatlakesfisheriestrail.org
Great Lakes Fisheries Heritage Trail - Great Lakes Fisheries Heritage Trail
www.greatlakesfisheriestrail.org
November 6, 2025 at 6:53 PM
drfishsg.bsky.social
Another #GarWeek spotlight species is the Bowfin. Check out this young of the year bowfin from a Green Bay coastal wetland. #GreatLakes
November 6, 2025 at 5:57 PM
drfishsg.bsky.social
Today #GarWeek is visiting some other species. Here are some pictures of spawning Lake Sturgeon in the Wolf River. Wisconsin is home to the largest lake sturgeon population in the world in the Lake Winnebago system, largely because of early protection of the species here.
A sturgeon tail breaks the surface and makes a splash. Sturgeon mouth protruding while feeding to suck up a snack (like a vacuum). Several sturgeon actively spawning.
November 6, 2025 at 5:30 PM
Reposted by Titus Seilheimer
garlab.bsky.social
And learn about the long-living Buffalo!

Studying fish like these can give us and other scientists insight into evolutionary biology, and allows us to advance our understanding of how our current ecosystems could’ve looked like millions of years ago. #GarWeek
November 6, 2025 at 5:09 PM
Reposted by Titus Seilheimer
garlab.bsky.social
Marvel at the massive Sturgeon! #GarWeek
November 6, 2025 at 5:09 PM
Reposted by Titus Seilheimer
garlab.bsky.social
Read about the Bowfin, the gar’s closest living relative. #GarWeek
November 6, 2025 at 5:08 PM
Reposted by Titus Seilheimer
garlab.bsky.social
On the fourth day of #GarWeek, we’re celebrating other native, ancient fish species! Check out these species bios to get an idea of what other ancient fish besides gar reside in North America and beyond.
November 6, 2025 at 5:08 PM
drfishsg.bsky.social
Lights in the sky, Manitowoc WI.

#Auroraborealis
November 6, 2025 at 3:28 AM
drfishsg.bsky.social
For #GarWeek, here is a juvenile gar from southern Green Bay that we encountered this summer. Look that those pectoral fins go! After length measurement, this fish was released on site. #GreatLakes
November 5, 2025 at 8:25 PM
drfishsg.bsky.social
Some lakes are clear for the right reasons. Spent last week in Sylvania Wilderness exploring remote, forested lakes. Picture of my canoe sporting a larval whitefish sticker I got at a showing of @alltooclearfilm.bsky.social!
Red canoe with whitefish sticker in the foreground and a wilderness lake in the background. Mostly conifers on the shore but some color from leaves.
November 5, 2025 at 1:40 PM
Reposted by Titus Seilheimer
drkatfish.bsky.social
Sea lamprey control - a joint effort between the US + Canada - has allowed lake trout to make a comeback in the #GreatLakes over the past 60 years. This fall marks the 3rd year the Fond du Lac Band has been able to practice the tradition of subsistence netting www.mprnews.org/story/2025/1...
Fond du Lac Band resumes tradition of harvesting Lake Superior trout to continue culture, feed students
Lake trout were nearly wiped out in Lake Superior by the invasive sea lamprey. But a successful control project has helped bring the trout back from the brink. That’s allowing the Fond du Lac Band of ...
www.mprnews.org
November 4, 2025 at 5:50 PM
Reposted by Titus Seilheimer
garlab.bsky.social
Join Gabby for a day in her life as a member of #GarLab!

#DayInMyLife #DIML #GarWeek #Conservation #Fisheries #GarLab #Garology #FishSciComm #SciComm
@solomonrdavid.bsky.social
November 4, 2025 at 4:53 PM
Reposted by Titus Seilheimer
solomonrdavid.bsky.social
GAR WEEK 2025 is HERE!!!

Join @garlab.bsky.social as we celebrate these awesome living fossil fishes and freshwater biodiversity for #GarWeek!

We look forward to hearing from YOU with any gar pics, puns, stories, GARtwork and questions this week!
November 3, 2025 at 3:04 PM
drfishsg.bsky.social
Characteristics of the black bass tournament fishery in eastern Lake Ontario and the St. Lawrence River

#GreatLakes 🧪

www.sciencedirect.com/science/arti...
Characteristics of the black bass tournament fishery in eastern Lake Ontario and the St. Lawrence River
The Laurentian Great Lakes provide unique challenges to obtain biological information for largemouth (Micropterus nigricans) and smallmouth (Micropter…
www.sciencedirect.com
November 3, 2025 at 4:00 PM
drfishsg.bsky.social
The effect of diet-derived thiaminase on survival, growth, and liver transketolase activity in two strains of lake trout (Salvelinus namaycush)

#GreatLakes 🧪

www.sciencedirect.com/science/arti...
The effect of diet-derived thiaminase on survival, growth, and liver transketolase activity in two strains of lake trout (Salvelinus namaycush)
The consumption of invasive, high-thiaminase prey fishes can cause thiamine deficiency, which has been hypothesized to be a major barrier for lake tro…
www.sciencedirect.com
November 3, 2025 at 3:59 PM
drfishsg.bsky.social
Mass balance modeling highlights the role of the littoral zone in modulating the cycling of phosphorus in a large, multi-basin lake (Lake Erie)

#GreatLakes 🧪

www.sciencedirect.com/science/arti...
Mass balance modeling highlights the role of the littoral zone in modulating the cycling of phosphorus in a large, multi-basin lake (Lake Erie)
Excess land-derived input of phosphorus (P) is generally considered the primary driver of eutrophication symptoms in large lakes, including Lake Erie,…
www.sciencedirect.com
November 3, 2025 at 3:56 PM
drfishsg.bsky.social
Forgot the alt text:

Ink and watercolor sketch of a creepy fish face peaking up from the sand. Kind of looks like a mummy
drfishsg.bsky.social Titus Seilheimer @drfishsg.bsky.social · 8d
Spooky theme of #SundayFishSketch is the marbled stargazer. A nightmare fish buried in the sand and waiting to ambush its prey. www.discoverwildlife.com/animal-facts...
November 3, 2025 at 11:26 AM