[env-trinity] Proposed Suction Dredging Regs

FISH1IFR@aol.com FISH1IFR at aol.com
Thu Mar 8 19:13:52 PST 2012


In a message dated 3/8/2012 6:33:06 P.M. Pacific Standard Time,  
bhill at igc.org writes:

Suction  dredges are designed to remove heavy metals, esp., gold and 
platinum, from  waterways.  Because mercury and lead are almost as heavy as gold, 
suction  dredges REMOVE mercury and lead from waterways along with gold and 
other heavy  metals.  This blatant fact known to every dredge miner is 
carefully  circumvented by those opposed to small stream miners. 
Doesn't  it make sense that removing mercury from waterways improves the 
health of the  waterway? 
A  test of whether dredging stirs up or removes mercury from waterways 
would be  very simple to demostrate. 
Brian  Hill
Brian....
 
I know the above in an "article of  faith" for suction dredge miners, and 
one of their great defensive talking  points, but it is also dead wrong on 
the science.  While the dredge might  catch some otherwise dormant and 
sequestered subsurface mercury, it also  stirs it up and methylates the rest (and 
likely a lot more than it catches),  thus creating the most water soluble 
(and toxic to humans and fish) chemical  compounds of mercury known.  
 
See, for instance, the USGS study Mercury contamination in  California’s 
South Yuba River, available at:  
_http://www.usgs.gov/newsroom/article.asp?ID=2686_ (http://www.usgs.gov/newsroom/article.asp?ID=2686) 
 
In short, the tests have been  done, in many streams under varying 
conditions, and the conclusion is  inescapable that suction dredging releases 
otherwise sequestered river  bottom mercury that constitutes a human as well as 
fish health  hazard.  And this is quite aside for any other adverse impacts, 
which also  occur (increased sediments, disturbing or destroying intra-gravel 
eggs,  disrupting noises affecting fish behavior, etc.).  All these suction 
dredge  impacts are well documented.  In fact, CDFG did a good literature 
search of  the scientific literature showing these various impacts, which is 
included as  Appendix D to the Draft EIR and (for those hardy souls who like 
to see the  source of such assertions) is attached.  
 
There is thus every good  reason, both for environmental and human health 
reasons, to minimize suction  dredge impacts in many California streams, and 
in many others to ban it  altogether.  
 
======================================
Glen H. Spain, Northwest  Regional Director
Pacific Coast Federation of Fishermen's Associations  (PCFFA)
PO Box 11170, Eugene, OR 97440-3370
Office: (541)689-2000 Fax:  (541)689-2500
Web Home Page: _www.pcffa.org_ (http://www.pcffa.org/) 
Email:  fish1ifr at aol.com
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