Rock Snot in the Bear River

[finefins]

An extensive algal bloom on the Bear River between Rollins Reservoir and Lake Combie has been confirmed as Didymosphenia geminata by the US Geological Survey lab in Colorado. The entire range of infestation is unknown at this time. It has been found as far upstream as the PlumTree picnic ground and as far downstream as the old Chevreaux gravel plant.

DFG has been notified. What is perplexing, is that the river has been under study for a FERC relicensing in 2013. I see spray paint markers right in the midst of the heaviest infestations of Didymo, but am not aware that its presence has even been mentioned, let alone its capacity to clog screens or impair power generation equipment. What is more alarming, is that agencies have the capability to trade waters between the Bear River and American River. (This may also be true of the Bear and the Yuba). This stuff has the capacity to completely blanket spawning gravels. For more info, check out www.creekman.com for updates.

[Ed Wahl]

Welcome to our little board finefins.(real names much preferred)

Didymo has taken over several reaches of the North Fork and Middle Forks of the American River. It's taken over some stretches of the Rubicon River during the warmer months also.

Surprising how little publicity this algae has garnered considering it's fairly recent profligration. It only started doing this in the last 10 to 15 years.

From what I've read there's not much to be done about it except hope that it doesn't kill the aquatic invertebrates outright and that it disappears on it's own.
I haven't noticed it during the spring spawn but if you have let us know.

The usual hydro project tunnels are so big I don't think Didymo is much of a concern to the project owners.

They'd be happier to not have to deal with fish or fishermen.

Ed Wahl

[DFrink]

This is a bummer, one of my favorite places to fish close to home.

[Phil Synhorst]

Hopefully it will not last long.[-o<

As Ed said, it has infiltrated other streams in the past, but is now gone. Strange though, that it proliferated in a good water year.:question: When it hit the Rube good, it was low/warm water years.

[finefins]

The biologist who collected these samples says there are other algal infestations that are mistaken for Didymosphenia, and the Rubicon is not known to have Didymo in it. But then . . .

I do think that hydrologic forces can sweep the river clean, but the algae does have spores that are just waiting, waiting, waiting. Obviously, I will be watching, hoping, waiting.

[Dean Y.]

http://www.sacbee.com/2010/08/30/2991654/disgusting-algaes-spread-perplexes.html?pageNum=2&mi_pluck_action=page_nav#Comments_Container

[SHigSpeed]

I was surprised to find out that it's a native plant! So much for "invasive". That said, it didn't say what waterways it was native to...

_SHig