So dredging is bad for fish.....

Mad Machinist

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Aug 18, 2010
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Suction dredging is bad for fish | California WaterBlog

Suction dredging seems like a fairly innocent pastime. A few folks go to a stream on a nice summer day with a portable device to suck tiny amounts of gold out of a stream bottom. The device basically is a floating sluice box equipped with a gas-powered pump that sucks up water and gravel through a hose. A diver vacuums the stream bottom with the hose and the material is flushed into and through the sluice box where the heavier material, including gold, is collected. So why is there a moratorium on suction dredging in California?


The problem is that suction dredging in streams can harm fish and fisheries, especially salmon and steelhead. Because of this, dredge miners must obtain a permit from the California Department of Fish and Game (DFG) for about the cost of a fishing license. In the past, on average CDFG issued about 3400 permits per year although nearly 18,000 were issued in 1980 when gold prices were high. Given the recent trend in gold prices, this could happen again.
Not all streams contain gold. The streams that do have been mined repeatedly, creating cycles of mining disturbance. Many have more or less recovered from hydraulic and other severe mining of the past but suction dredging could easily reverse their recoveries. Is churning up hundreds of square meters of river bottom worth the 3.4 oz of gold the average dredger collects in a season? So if dreding is bad for the fish, then why are we having record salmon runs? Record salmon run expected | Crescent City California News, Sports, & Weather | The Triplicate. With the life cycle of Chinook salmon, they may spend 1 to 8 years in the ocean (average 3 to 4) before they return to the river they were born in. Further the fry spend 12 to 18 months in the river before they migrate to the ocean. This puts many of this run squarely in the high point of dredging due to the price of gold.


In the Klamath Basin, the Karuk Tribe became so upset with the impact of dredgers and dredging on fish in their traditional waters that they sued DFG in 2005 for not adequately protecting the environment. As a result, in 2009, a court order mandated a stop to all dredge mining until further notice. A month later a state law (SB 670) halted suction dredging until DFG completed the court-ordered review of the permitting program and took action to correct any problems that might exist. The draft review report is now out and the information and analysis supports continuing the moratorium on dredging until better regulations and more funding for enforcement are in place (see Suction Dredge Permitting Program - California Department of Fish and Wildlife). Maybe if the Karuk Tribe actually understood the problem they wouldn't be throwing a fit.


The effects of suction dredging on fish are well described in the peer-reviewed papers Harvey (1986) and Harvey and Lisle (1998) and in the numerous citations in the two DFG review documents (see below “Further Reading”). The effects vary according to size of stream, fish species present, season of dredging, and frequency and intensity of dredging. Direct effects include trapping invertebrates and small fish in the dredges, altering the habitat that supports fish food supply, and changing channel structure to make it less favorable for fish. In the Klamath, piles of dredge tailings in the Salmon and Scott Rivers and their tributaries create attractive spawning grounds for salmonids. But these tailings are so unstable that they are likely to scour under high flows, greatly reducing survival of the embryos placed within the gravel. If a suction dredge can pick up this material making it unstable and subject to scour, then wouldn't this very same material be subject to the scour effect during high flows. And if this is so, then would the stream channel also be subject to the very same changes you blame on dredging? You may also want to go back and read the literature you site. Per Harvey (1986), Dredging significantly affected some insect taxa when substrate was altered. A recolonization experiment showed that numerical recovery of insects at dredged sites was rapid. Local turbidity increases below active dredging probably did not affect invertebrates and fish. Per Harvey and Lisle (1998), The scientific literature contains few peer-reviewed studies of the effects of dredging, but knowledge of dredging practices, and the biology and physics of streams suggests a variety of mechanisms linking dredging to aquatic resources. Effects of dredging commonly appear to be minor and local, but natural resource professionals should expect effects to vary widely among stream systems and reaches within systems.

The key is that suction dredging represents a chronic unnatural disturbance of habitats supporting fish that are already likely to be stressed by other factors.
A more immediate effect of dredging is chronic disturbance of fishes, which can change their behavior so they move to stream areas with less favorable conditions. I am particularly concerned with dredging in or near thermal refuges (cold pools) that are key for survival of juvenile salmonids. As discussed in the 2003 National Research Council (NRC) report (of which I am a co-author) and references therein, the Klamath River and some of its tributaries can reach temperatures in excess of 65-70ºF during the day in late summer. Such temperatures are very stressful or even lethal for many salmonids, so the fish seek out cooler areas, where small tributaries flow into the river or there is upwelling of ground water. Juvenile coho salmon, Chinook salmon and steelhead will often be packed into these areas during the day. When I swam in the river with a mask and snorkel to count the fish, I was struck by the concentrations of fish in the refuge areas (and the lack of them in the main river) and by how much even a minor disturbance of this habitat reduced the overall ability of the river to support fish. Maybe if you actually understood the real problem this would not be the case. To understand the real probem here you need to look a lot higher up the mountain. Like how there is now over 1000 trees per acre in the Sierra Nevada's instead of the 20 to 50 per acre based on historical conditions.
Ever wonder why we are in a drought?

Adult salmon and steelhead are also subject to being disturbed by intense dredging activities. I am particularly concerned with spring-run Chinook salmon, a species with which I have worked closely. Adult spring-run Chinook spend the summer in river pools, especially the Salmon River (and its forks). They have to survive the summer without feeding, using fat reserves and oils they bring up from the ocean. Chronic disturbance of the type created by dredging and dredgers can increase stress on these fish and has the potential to reduce their over-summer survival. When I was participating in a diving survey of spring-run Chinook in the Salmon River a few summers ago, I was impressed by the fact that suction dredgers had to agree not to dredge on the survey day so the water would be clear enough to see the fish. The next day, I observed pools cloudy with sediment again. So if that turbidity from the dredges is detrimental to the fish, the would you kindly like to quantify the effects of high turbidity during summer floods. Better yet, explain the effects of turbidity on this: [URL]http://www.triplicate.com/News/Local-News/Record-salmon-run-expected[/URL]. Stream flows are to be increased to 3200 cfs to counteract the effects of Ichthyopthirius multifilis due to the record run of salmon.

An often-overlooked impact of dredging is that the people involved may live on or close to the stream in remote areas for weeks at a time, where they also swim, bathe, fish (sometimes illegally), and leave trash behind. Such activity can cause spring-run Chinook to use up precious energy reserves if they have to move to less favorable areas or swim about avoiding people. Guess we need to tel lthe Karuk Tribe they can no longer harvest the salmon then due to the stress they place on the fish.

It is important to note that the Klamath River and its tributaries, the focus of the Karuk lawsuit, support the highest diversity of sea-run fishes of any California river: Coho, chum and Chinook salmon, coastal cutthroat trout, steelhead, eulachon, green sturgeon, white sturgeon, Pacific lamprey and river lamprey. This is the reason, of course, why the river also supported major fisheries by the native peoples who live along the river. Today virtually all the species are in decline or threatened with declines from multiple factors (NRC 2003). Therefore, it should be assumed that dredging causes harm, unless it can be proven otherwise. So if we have to ASSUME that, with the lack of evidence otherwise, that dredging causes harm, then we can safely assume that academia, yourself included, basically have absolutely no idea what you are talking about (unless it can be proven itherwise) and are simply spouting whatever to make yourself look important.


One reason for taking this conservative position is that we simply do not know much about the effects of dredging on many species, especially when the intensity of dredging is increasing. For example, juvenile Pacific and river lamprey live in soft materials along the stream edge or in slow-moving sections of stream. Dredging of areas where the juveniles are abundant will push them into the water column where they can be readily consumed by predators, contributing further to the decline of the species. So what happens during high flow events when these areas are removed by erosion?

Even for salmonids, information on the effects of dredging, with the exception of a few studies such as that of Harvey (1989), is largely anecdotal or in non-peer reviewed reports (see, for example, the bibliography of DFG EIS). Studies are also largely confined to looking at immediate effects of single dredges and they do not examine the cumulative or long-term effects of multiple dredges and activities associated with the dredges. Indeed little has changed since DFG (1994, p. 71) listed the need for additional studies on practically every important aspect of the environmental impacts of dredging. Harvey and Lisle (1998) present a strategy for acquiring much of the needed information.
In my opinion, no dredging should be allowed where sensitive salmonid species are present, including spring run Chinook salmon and coho salmon. The CDFG draft EIS/EIR points to this approach, as well as towards instituting strict, if complex, new regulations elsewhere. If dredgers don’t like these results, they should pay for an appropriate, independent study to be done. The burden of proof should lie with the miners to prove they are not doing harm to fish and fisheries, rather than with the beleaguered management agencies to prove dredging is doing harm in every case. So if we pay for the study and it proves you wrong, then will you resign your position since you have no idea what you are talking about? And since when is the burden of proof on someone to prove their right to do something when it is currently codified in Federal Law. And by the way, you might want to reread NEPA and pay special attention to the part about how the law effects "man's environment" and the "human environment".
 

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This is what I suspect has happened to cause the record salmon runs.

When we look at the Sierra Nevada's, based on historical reports and pictures, we find that there were around 20 to 50 trees per acre. In many places there are now over 1600 per acre. This sets up a situation that severely impacts the available water for other areas. What we have now is a whole lot of trees competing for and using up a limited resource resulting in a forest that is extremely susceptible to extreme fires and also in an area that is extremely susceptible to bark beetle invasion.

The water that once was stored in river banks, aquafers, and wetlands (and slowly released over time) is now being used up by too many trees per acre. So now there is less for everything else resulting in reduced water flows. How did we get here? Anti-logging policies.

This will also effect any and all rivers in the Sierra Nevada's by reducing flows thus allowing sediment to accumulate in slower moving areas and also slowing down faster areas of the river allowing sediment accumulation. Sediment transport is a natural thing and needs to be allowed to happen. It is a necessary mechanism that can revitalize and protect many areas. Case in point: http://www.sciencedaily.com/releases/2013/02/130213132504.htm


So what has happened to produce the record salmon runs is dredging. Even with the low flows that allowed sediment to accumulate, the dredgers came in, with the high price of gold, and basically resuspended the accumulated sediment and allowed it to move down stream mimicking the natural process of sediment transport. Thus leaving a great many areas with a cobble substrate necessary for the salmon to breed in. And with suspending many of the invertabrates, the fry in the river were allowed to get plenty of feed leading to an increased survival rate.

I am probably going to edit and add more to this as it comes to me. I am going to try and keep this simple for all to understand. Getting into things like Rouse numbers, but it doesn't do any good if you all do not understand.

Another little factoid popped up and it time for a little math lesson there, Herr Professor.

According to the Federal Highway Administration, http://www.environment.fhwa.dot.gov/ecosystems/wildlife/fish5.asp, a 13 cubic meter/sec flow is enough to move a 4 ft dia boulder.

To get Cubic feet per second multiply 13 cubic meters per second time the conversion factor of 35.315 and you get 470 cubic feet per second. http://www.ehow.com/how_7982162_unit-cubic-feet-per-second.html

A 4 ft diameter boulder has a little over 33 cubic foot in it. http://wiki.answers.com/Q/How_do_you_get_the_cubic_feet_volume_of_a_ball

So 24 x 24 x 24 x 4.188 = 57894.912 Cubic inches / 1728 cubic inches per cubic foot = 33.504 cubic foot

Granite averages 166.5 lbs per cubic foot so 33.504 x 166.5 lbs per cubic foot = 5587.416 pounds

So if a flow of 470 cfs can move a boulder that weighs nearly 3 tons, what chance does a little rock that a dredge pick up have. Yet dredgers get blamed for the shifting of the river.

Coincidentally, I found out that the minimum flow of the Klamath has been set at 470 cfm since 1991. http://en.wikipedia.org/wiki/Klamath_River It's under natural history.

So what this is telling me is this river is in a constant state of flux and whatever small amount of material a dredge moves in basically inconsequential under normal flows. Under reduced flows, dredging helps suspends the sediment and keeps it from building up.
 

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The government is trying to point fingers at dredgers. The culpabilty lies with poorly planned hydro storage. Fish ladders and hatcheries were almost an afterthought. Low flows and high temperatures kill fish not minute quantities of turbidity. Why take the blame yourself when you can blame someone else.
 

Many media outlets WILL publish the twisted information that the environuts provide to them because the money is good for doing it. They will NOT publish "True Science" reports that refute what the environuts are touting because the uproar from those that pay them handsomely for publishing total crap, would put the media outlets out of business. Follow the money and have your opinions spoon-fed to you without opposition........that's the way it seems to me anyway :hello:
 

Many media outlets WILL publish the twisted information that the environuts provide to them because the money is good for doing it. They will NOT publish "True Science" reports that refute what the environuts are touting because the uproar from those that pay them handsomely for publishing total crap, would put the media outlets out of business. Follow the money and have your opinions spoon-fed to you without opposition........that's the way it seems to me anyway :hello:

Very close but not quite. What has happened is the '60-'70's era hippies have grown up and now the inmates are running the asylum. Hence the reason we are basically going to hell in a hand basket.
 

Let's start a petition to ban dredgeing the shipping channels in Singapore!
 

We should dispose our trash correctly.
 


I had to make some popcorn for this one.

So you want to use a country whose environmental law is still in its infancy as a reason to ban dredging here. All I can say is wow. And by the way if you actually read about what is going on in Singapore, that pollution is from industrial sources. Last I checked we passed the Clean water Act in 1972 specifically to deal with stuff like this. And we have effectively eliminated that problem. Next!
 


And this is a dredger's problem how? Scrap the bottom of the barrel much?

We have refuse laws to deal with things like this.

Edit: I just remembered this.

Remember those mining companies that are just oh so bad. READ THIS: http://fcx.com/sd/pdfs/audits/Executive_Summary_Audit_PTFI_2011.pdf

Unlike enviro nuts who just cry about a problem, a mining company is doing something about it.

And when your done reading that, look up ISO 14001. Nevermind. http://www.iso.org/iso/iso14000
 

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messing with the water doesn't do a thing to the fish eh?

Hawaii molasses spill killing thousands of fish

nobody is saying that "messing",with water isnt bad for fish,hell,just last week in China Millions of fish were killed at the hand of man(how many of those fish will end up on our market?)What we are saying is that dredging is not bad for fish,quite the contrary...and scientific fact backs that up

Studies have shown that Hydro ElectricPlants in the upper Klammath Basin are raising the water temps to lethal(to fish)heights,and the pesticide run off of ag ops is also detrimental to the fish.The Environuts are wanting to tear dams out that have a hundred years of silt build up...you remove those dams and you damage that waterway indefinetly
 

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I know sir...was just being a pill..
everything humans do, effects the environment...good or bad...who knows? it takes years for the damage to show up in most cases.
here, just add sugar, fish die. in the ocean...not a contained stream or lake.
 

I know sir...was just being a pill..
everything humans do, effects the environment...good or bad...who knows? it takes years for the damage to show up in most cases.
here, just add sugar, fish die. in the ocean...not a contained stream or lake.

Donald,

I am going to show you something that is bad for fish. We are expecting the river here to crest at 25 feet and 35,000+ CFS. This is because of the Whitewater Badly Fire and the resultant burn scar being hydroscopic.

Glenwood got destroyed last night into this morning. It was just short of a major flood. The Frisco there crested at 18.87 feet and 19 feet is major flood stage. And for all intensive purposes the Catwalks are gone. Whitewater crested at a little over 19 feet and over 17,000 CFS.

All of this because of the "rules" governing wilderness areas.

I get some video up here later. I'm heading out to film the crest here.
 

As promised Donald,

Things that are bad for fish:

Crested at a little over 24' and 31,000 CFS.



Here's another one:



Both of these are the direct result of rabid environmentalism that says everything is bad.


Unlike many, including more than a few Professors, I actually do read and understand Biological Opinions and most I read are less than stellar to be nice.

And I have even more devastating video to put up once I get to it.
 

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