Resident Shad??

[Pitch Pocket]

There was a turbine that leaked oil into the Columbia yesterday at The Dalles and they found about 180 dead shad as a result.

Dead Shad Found in the Columbia

I thought shad only come up into the Columbia to spawn. Is it a pilot run or do we have resident shad in the river?

[Miss B Haven]

Downstream Shad "smolts" I'd guess??????

[TillamookChinook]

I was very disappointed to learn that the Corps of Engineers still has any PCB oil in transformers in their dams. Any leak is likely to go directly into the river. How many years have they had to replace the oil or the transformer since PCB oil was recognized as a hazard? 20 years? 30 years? This is shameful.

TC

[Paddlefish]

TC:

The PCB containing oil was, indeed, replaced years ago. However, the new oil is inside the same equipment which originally contained the icky stuff and a certain small amount is somehow absorbed into the new oil.

The concentration is measured in parts per million, according to what I read, and still well below the EPA maximum allowable levels -- if you can trust the EPA.

[skein]

Paddlefish,

I like your questions and have asked myself those very things over the years; how can we have that many fish in the system every year and not have some measurable impact for good or bad. Yet very little is published about shad except where they came from, how they got here, how they spawn, etc, but little about their overall effect on the ecosystem.

Any bio's out there know?

Skein

[Silver Hilton]

I have pulled small shad from the stomachs of walleye, and seen scads of them on what I am guessing is their downstream migration. Last june, I saw large schools around the Kalama area, which were 4 to 6 inches long. I'm guessing that was the downstream migration.

[Nick Amato]

I've seen hundreds of adult shad holding in the fast water below the falls on the lower John Day River in November. Always wondered what they were doing there at that time of the years??

[Paddlefish]

I'm with you, Mel. That was my first guess too.

It's funny, though. Bonneville reported 4.5 million upriver adult shad in 2003, and those shad can broadcast a LOT of shad roe, :shocked: which in turn becomes how many, many millions of baby shad?

Yet, through my many years of studying Columbia River fish and fisheries, I've never found much of anything about those hordes of shad "smolt" and their effects on the lower Columbia ecosystem.

How soon, how quickly, and at what size do they move downstream?

Are they eating along the way? If so, what?

Are they eaten along the way? If so, by what?

Do they disappear to the Pacific in the fall and winter when there's (relatively) little mainstream Columbia salmon and steelhead smolt presence, or do they dawdle until all our beloved salmonid smolts come down with the spring freshets? Are they competing with the salmon/steelhead smolt for the same food sources along the way?

And, finally, should I be capturing them by the thousands and selling them as sturgeon bait or, perhaps airfreighting them to Tokyo as the latest trend in exotic sushi? (Guaranteed free of mad cow disease. :grin: )

So many questions . . .

[Chromaflage]

From Article:
The leak has caused oil spotting as far downstream as Bonneville Dam and sent a mileslong sheen of oil downriver. The only known wildlife kill has been the discovery of more than 180 dead shad in The Dalles Dam's slot gates.

<font size="2" face="verdana,arial,helvetica">FYI - this is a media report and there has been no postivie correlation between the dead shad and the release. Not saying that it's not possible, but there is not yet any scientific evidence that has been publsihed that confirm this.

ORS