Michael Mahon, PhD
@mmahon.bsky.social
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.
Duluth, MN.
In short, fish biodiversity in U.S. streams are changing fast.
- Cold streams are losing biodiversity
- Warm streams are gaining in a homogenized way
- Human choices will shape the future of freshwater fish
Free access in first post.
www.nature.com/articles/s41...
- Cold streams are losing biodiversity
- Warm streams are gaining in a homogenized way
- Human choices will shape the future of freshwater fish
Free access in first post.
www.nature.com/articles/s41...
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.
www.nature.com
September 24, 2025 at 5:08 PM
In short, fish biodiversity in U.S. streams are changing fast.
- Cold streams are losing biodiversity
- Warm streams are gaining in a homogenized way
- Human choices will shape the future of freshwater fish
Free access in first post.
www.nature.com/articles/s41...
- Cold streams are losing biodiversity
- Warm streams are gaining in a homogenized way
- Human choices will shape the future of freshwater fish
Free access in first post.
www.nature.com/articles/s41...
What can be done?
- Restore riparian forests to cool waters
- Limit introductions & spread of non-native fishes
- Protect local species before losses become irreversible
- Restore riparian forests to cool waters
- Limit introductions & spread of non-native fishes
- Protect local species before losses become irreversible
September 24, 2025 at 5:08 PM
What can be done?
- Restore riparian forests to cool waters
- Limit introductions & spread of non-native fishes
- Protect local species before losses become irreversible
- Restore riparian forests to cool waters
- Limit introductions & spread of non-native fishes
- Protect local species before losses become irreversible
When warming streams also had more stocked or introduced fishes, local non-game species took the hardest hit, declining in both abundance and richness.
September 24, 2025 at 5:08 PM
When warming streams also had more stocked or introduced fishes, local non-game species took the hardest hit, declining in both abundance and richness.
“Average” or cool streams are stable. Streams in the intermediate range showed minimal biodiversity change. Their mix of species with different thermal tolerances may provide a buffer against changing stream temperatures.
September 24, 2025 at 5:08 PM
“Average” or cool streams are stable. Streams in the intermediate range showed minimal biodiversity change. Their mix of species with different thermal tolerances may provide a buffer against changing stream temperatures.
Warm streams show the opposite trend.
Abundance rose 70% and richness rose 15%. But this came with a big downside: fish communities became homogenized. Opportunistic minnows & shiners replaced larger periodic species.
Abundance rose 70% and richness rose 15%. But this came with a big downside: fish communities became homogenized. Opportunistic minnows & shiners replaced larger periodic species.
September 24, 2025 at 5:08 PM
Warm streams show the opposite trend.
Abundance rose 70% and richness rose 15%. But this came with a big downside: fish communities became homogenized. Opportunistic minnows & shiners replaced larger periodic species.
Abundance rose 70% and richness rose 15%. But this came with a big downside: fish communities became homogenized. Opportunistic minnows & shiners replaced larger periodic species.
Cold streams are in trouble.
Fish abundance fell 50% and richness dropped 30%. Small-bodied, cold-adapted species declined, while larger game fishes (like trout) increased. Cold-water biodiversity is eroding fast.
Fish abundance fell 50% and richness dropped 30%. Small-bodied, cold-adapted species declined, while larger game fishes (like trout) increased. Cold-water biodiversity is eroding fast.
September 24, 2025 at 5:08 PM
Cold streams are in trouble.
Fish abundance fell 50% and richness dropped 30%. Small-bodied, cold-adapted species declined, while larger game fishes (like trout) increased. Cold-water biodiversity is eroding fast.
Fish abundance fell 50% and richness dropped 30%. Small-bodied, cold-adapted species declined, while larger game fishes (like trout) increased. Cold-water biodiversity is eroding fast.
Not to mention the coming dissolution of ORD.
May 3, 2025 at 5:41 PM
Not to mention the coming dissolution of ORD.
But I do have baseball opinions!
April 4, 2025 at 11:04 PM
But I do have baseball opinions!