The Olympics are Calling and the Great Plains Fish Answer
With the 2024 Summer Olympics in Paris set to kick off, we’ll soon find out who the world’s fastest humans are on the track or in the pool. But have you ever wondered who are the fastest swimmers and highest leapers among the Great Plains fish species?
Researchers in Nebraska conducted a mini-Olympic games for several plains fish species, including some that are commonly observed in the South Platte River downstream of Metro’s outfalls.
Back in 2016, these researchers constructed a 10-liter swim tunnel to test maximum swimming performance and an artificial waterfall with an adjustable weir to test jumping ability. When you think of world-class fish athletes, you may picture a large fish like the steelhead trout that can jump up to 11 feet into the air while climbing waterfalls during epic migration runs or accelerate from 0 to 25 miles per hour in one second. But unfortunately, the steelhead trout isn’t found in warm plains rivers and streams, so it was disqualified from the Great Plains Fish Olympics. All competitors in these Olympics were between 1 and 3 inches long.
Here are the results from the experiment:
| Species | Average Length (in) | Maximum Swimming Velocity (mph) | Jump Height Completed (in) |
| Plains Topminnow | 2.2 | 1.2 | 1.6 |
| Northern Plains Killifish | 2.7 | 1.6 | 2.4 |
| Western Mosquitofish | 1.9 | 1.1 | 1.2 |
| Red Shiner | 2.2 | 2.0 | 1.6 |
| Sand Shiner | 2.3 | 1.9 | 1.2 |
| Black Bullhead | 2.4 | 1.6 | 0.4 |
| Channel Catfish | 3.0 | 1.8 | 2.4 |
| Bluegill | 1.9 | 1.4 | 0.0 |
| Green Sunfish | 2.5 | 1.7 | 5.1 |
| Largemouth Bass | 2.7 | 1.9 | 2.8 |
And the Gold Goes to…
In a thrilling upset, the diminutive red shiner got the gold medal for fastest swimmer with a blazing maximum speed of 2.0 miles per hour, just a pectoral fin in front of its close relative the sand shiner and the largemouth bass.
As for the high jump, I’m so proud of the green sunfish, which snagged a first-place finish with an amazing leap of 5.1 inches! Metro’s Water Quality Division is particularly fond of the green sunfish, as they are some of the most beautiful fish we see during our annual fish surveys along the South Platte River. And as for the bluegill, it was an Olympics to forget. These fish failed to clear even the 1 cm barrier. The bluegill is in the same family (Centrarchidae) as the first-place-winning green sunfish (AWKWARD)!
Not Just Fun and Games
While you may chuckle imagining these undersized fish athletes giving it their all for glory, these Great Plains Fish Olympics aren’t just fun and games. Plains fish often require large-scale movements to maintain winter refuge, spawning, and predator avoidance. As the researchers note, human-caused activities including the construction of dams and road crossing structures have altered streamflow characteristics (such as depth and velocity), resulting in a fragmented system that hinders fish and aquatic macroinvertebrates’ ability to disperse.
It’s Also About the River
Results from these types of studies are critical for determining what river conditions may act as a barrier to fish passage. Like other large urban rivers, the South Platte River downstream of Denver is heavily impacted by multiple stressors including urbanization, channelization, hydromodification and the presence of large irrigation dams. Fish behavior studies like these help inform design criteria for installing and maintaining instream structures.
For more information about how Metro is constructing instream habitat improvement projects along the South Platte River to benefit native fish, including some species that participated in the Great Plains Fish Olympics, visit: https://www.metrowaterrecovery.com/innovations/south-platte-river-improvements/
Go here for more information regarding results from our annual fish surveys: https://storymaps.arcgis.com/stories/9a9620d0492a493eb959d305f41ddf97
