Biologists working in a fish hatchery near Shasta Dam grew increasingly concerned

[WB Staff]

A tray at the Livingston National Fish Hatchery near Shasta Dam contains offspring of endangered female winter-run Sacramento River chinook salmon that scientists injected with thiamine, also known as vitamin B1. A puzzling deficiency of the vitamin is afflicting baby salmon in California. (Heather Bell / UC Davis)

The biologists working in a fish hatchery near Shasta Dam grew increasingly concerned last year when newly hatched salmon fry began to act strangely — swimming around and around, in tight, corkscrewing motions, before spiraling to their deaths at the bottom of the tanks.

Certain runs of chinook salmon in California are imperiled; the hatcheries and the fry raised there are the federal government’s last-ditch effort to sustain these ecologically and economically vital fish populations.

So, when scientists observed the young salmon’s screwball behavior, they reached out to their networks in oceanography, ecology and fisheries: Had anyone seen anything similar? Did anybody know what was going on?

FULL STORY: https://www.latimes.com/environment/sto ... ento-river

[Dave Wilson]

any time I hear of a salmonid swimming in circles, I think of Whirling Disease, I'm sure it's been tested for. It's caused by a microscopic parasite that's really difficult to eliminate.

[Kelly Ripa]

Pretty sure Casitas trout have it.

[Robb R]

any time I hear of a salmonid swimming in circles, I think of Whirling Disease, I'm sure it's been tested for. It's caused by a microscopic parasite that's really difficult to eliminate.

I used to fish the Madison River in Montana in the early nineties , whirling disease was so bad , they considered not letting people fish the rivers at all ---- eventually the thought it was only effecting rainbow trout and not the brown trout . It was crazy to see mostly small rainbows just start swimming in circles at the surface and flowing downstream .
The eagles and osprey had a field day . Not sure if they ever solved it .
I was told it was a parasite that infected the brain of mostly young rainbows .