Subject: River spill produces gas bubble trama -- April this year!!

From: Mark Booker <[email-masked]>
Date: 9 May 1996 04:16:52 GMT

RIVER SPILL PRODUCES FISH SUFFERING FROM GAS BUBBLE TRAUMA

LEWISTON, Idaho--Migrating juvenile endangered salmon and steelhead have shown signs of gas
bubble trauma, a potentially fatal disease caused by excess gases, as high spill occurred
this week at Lower Granite Dam on the Snake River. The incidence of the trauma, early in the
spring juvenile salmon and steelhead migration season, is a sign that the federal government
is not adequately protecting the fish, a commerce group says.

The federal government altered winter operations to keep upstream storage reservoirs higher,
triggering the higher spills. In addition, several of the dam's turbines were turned off to
install a surface collector prototype designed to aid the migration of juvenile salmon and
steelhead.

The turbine closure, along with already high water levels in the river, meant excess water
had to be spilled over the dam. Dissolved gas levels rose above 130 percent, 20 percent
higher than state and federal environmental protection standards and 10 percent higher than a
recent waiver granted to the National Marine Fisheries Service to purposely conduct spills at
the Columbia and Snake river dams.

More than 30 percent of fish examined at the downstream Little Goose Dam on the Snake River
exhibited signs of the gas bubble trauma. The falling water, infused with excess oxygen and
nitrogen, in turn caused sign of gas build-up. Gas bubble trauma is potentially fatal to fish
and other aquatic life and is similar to the bends suffered by human deep sea divers.

The spill caused the season's first documented incidence of gas bubble trauma of the 1996
juvenile salmon migration season. Over the last two years, dissolved gas levels rose above
the allowable standard so often that the federal government halted the spill early. The
fisheries service will again conduct spill at the dams, but a river system already saturated
with water from this year's wet winter could prove lethal for fish.

This is a good example of bad things that could happen in the next two months as even more
water comes into the river system from spring runoff, said Bruce Lovelin, executive director
of the Columbia River Alliance for Fish, Commerce and Communities, a group that has opposed
spill as a way to help endangered salmon. Lovelin said the fisheries service should have done
more to protect the fish. The fisheries service has not but should be taking all actions
possible to protect these endangered salmon from high spills that will create lethal river
conditions, he said.

s/Mark from the land of the Mighty Columbia!!

---

From: [email-masked] (Thomas Roesch)
Date: 15 May 1996 16:02:49 GMT

In article <[email-masked]>, [email-masked] says...

>RIVER SPILL PRODUCES FISH SUFFERING FROM GAS BUBBLE TRAUMA

snip

>The turbine closure, along with already high water levels in the 
river, 
meant excess water
>higher than state and federal environmental protection standards and 
10 
percent higher than a
>recent waiver granted to the National Marine Fisheries Service to 
purposely 
conduct spills at
>the Columbia and Snake river dams.

Hi Mark,

I do not understand how it could come, that the dissolved gas level 
rises 
above 100 percent. The spilled water has excessive contact with air so 
that 
an excellent gas-transfer occurs. But the gas exchange is always into 
the 
direction of less concentration. Meaning if you use air as gas the 
concentration moves to state. That means if the concentration of the 
dissolved gas in the water is below 100 percent (state condition) the 
gas 
>from  the air goes into the water. On the other hand, if the 
concentration in 
the water is higher than state the gas evaporates into air.
 In my opinion it could never happen, that the dissolved gas level 
rises 
above 100 percent due to airation. Maybe the high concentration is 
caused by 
high photosynthesis of algae etc.

But another point. I am very interested in these "federal environmental 
protection standards". Could you please send me a e-mail how I could 
get 
these standards and the waiver you are talking about.

Thank´s in advance

Thomas

-- 
+---+  Thomas Roesch
|GhK|  Universitaet Gesamthochschule Kassel   Tel.: 0561-804-3538
+---+  Kurt-Wolters-Str. 3, D-34109 Kassel    Fax : 0561-804-3952
       e-mail  [email-masked]
       http://www.uni-kassel.de/fb14/wasserbau/Welcome.html

---

From: [email-masked] (Josh Hayes)
Date: 16 May 1996 16:39:46 GMT

>>> Thomas Roesch writes:
In article <[email-masked]> [email-masked] (Thomas Roesch) writes:

  Thomas> In article <[email-masked]>, [email-masked]
  Thomas> says...

  >> The turbine closure, along with already high water levels in the
  Thomas> river, meant excess water
  >> had to be spilled over the dam. Dissolved gas levels rose above
  >> 130
  Thomas> percent, 20 percent
  >> higher than state and federal environmental protection standards
  Thomas> 10 percent higher than a
  >> recent waiver granted to the National Marine Fisheries Service...

  Thomas> I do not understand how it could come, that the dissolved
  Thomas> gas level rises above 100 percent. The spilled water has
  Thomas> excessive contact with air so that an excellent gas-transfer
  Thomas> occurs. But the gas exchange is always into the direction of
  Thomas> less concentration....

It DOES seem strange to have saturation higher than 100%, doesn't it?
But it's true. The reason is that the water coming over the spillway
plunges into the tailrace below - at the dams in question, the
hydraulic head is typically around 30m - which entrains air bubbles in
the water, so for a time, more air is dissolved in the water than it
can ordinarily hold. It is true that this gas then dissipates
(outgasses), so that as the water moves downstream, the gas
concentration drops, but this turns out to be a not very rapid
process, so that tailwater concentrations of 130% decline at the next
dam to only about 120% (inter-dam distance is typically about
60-70km).

Unfortunately, the same gas concentrations are thus induced in the
blood of the fish swimming in the river, and as the nitrogen outgasses
>from  the blood, it produces tiny bubbles - this is exactly the same
process that produces trauma in decompression sickness ("the bends")
in SCUBA divers - which can lead to poor fish condition, trauma, and
death of the fish. The larger the fish, the worse the problem usually
is, but at the same time, relative gas concentration decreases with
increasing pressure, so fish that swim deep in the water column are
less vulnerable to gas bubble disease.

It has long been felt that deleterious effects begin to be seen when
gas levels rise above 110% (this is, I believe, the U.S. EPA
standard), although state standards here in the Pacific northwest are
somewhat more relaxed, allowing levels of up to 120%. 

Here are some useful Web resources on the subject:

http://www.newsdata.com/enernet/fishnet/fishletter/fishletter.html
NW Fishletter - this contains reasonably up-to-date information on
matters relating to Northwest salmon; the lead stories this year have
been about gas saturation.

http://www.teleport.com/~fpc/
The Fish Passage Center - this page provides information on fish
counts, transportation operations, and monitoring for gas bubble
disease, among other things.

http://www.cqs.washington.edu/dart/dart.html
The DART Page - Data Access in Real Time (DART) - this page is
maintained by my project, so I'm perhaps not unbiased about it, but it
provides a whole bunch of different kinds of data, up to date,
accessible in either tabular or graphical formats. Included are adult
counts, coded wire tag data, PIT tag data, and various river
environment parameters. My machine slows to a crawl when this gets
heavy use, but I don't care! Take a look!

Hope this helps,

Josh Hayes, Columbia Basin Research
--
     Josh Hayes	      [email-masked]	    PDGA #9665
	     Work: http://www.cqs.washington.edu/~josh
	    Fun: http://weber.u.washington.edu/~jahayes

---

From: [email-masked] (Thomas Roesch)
Date: 20 May 1996 07:40:23 GMT

In article <[email-masked]>, 
[email-masked]» says...

snip

>dam to only about 120% (inter-dam distance is typically about

Dear Josh,

thanks a lot for answering my questions. But I still have another one. Do 
you have any physikal explanation for this phenomenon. Is it due to the 
higher pressure in the tailrace or is it because of the high speed of the 
water on the spillway? Or is there anything else to explain this thing?

Thanks a lot in advance
Thomas Roesch