I have a place on a lake that was built back in 1937. When I was a kid back in the seventies I remember that they had a weed or algae problem. They had a float constructed that they put bags of copper sulfate on and let the wave action dissolve it into the lake. I have no idea how much that they put in the 25.4 acre lake then. My question is this could all the copper sulfate that they put in keep the benificial weeds from growing in the lake? What are your thoughts? An aeration system is now in place.

IMO, yes - excessive concentrations of copper can severely limit plant-growth - and cause many other issues since it never degrades (a heavy metal element).

Ok since we have the copper sulfate in the lake is there any way we can get it out of there other than dredging?

Copper carbonate and associated bound products are in the sediments until dredging. Bound copper as a heavy metal is a pretty stable compound. Some sediment chemistries can cause short term redissolving of bound copper depending on conditions, mostly shifts of aerobic vs anaerobic chemistries.

Bill, do you have time for giving a crash course in chemistry? I understand that copper is a required trace "mineral", to ensure the proper biological function of many organisms, but at what point does copper become toxic to humans? I am not being a naysayer here by any means, I SWEAR!! I know in sheep, you never feed anything with copper, but with cattle and goats, a little is a good thing. help me understand? And then you read "reports" and copper plumbing is not good for you, and modern PVC contains estrogen mimicking compounds,but drinking out of the ditch aint much good either.....any off the record, non-liable opinions? The whole metals thing has me confused?

James, I can't shed any light on the subject except for this:

When questioning the trout hatchery that I know, they said not to use any copper based product (i.e. Copper Sulphate or, Cutrine) within a month of wanting to stock trout, or when the fish are actually in the pond. How true this is, I have no idea. But, since I buy trout from him, I'm going to take him for his word and make sure not to use any.

Copper is a required trace metal/mineral for many organisms as with many other chemicals. When in excess these same chemcials can have toxic affects; i.e. salt, vitamins, water, etc. the list is extensive. Lots of scientific info is available on the fate of Cu and other heavy metals in the environment. Cu is on the hazardous chemical list for at least three gov agencies. Its use in lakes and ponds as an algacide has been banned in several states with probably more states to follow suit as more scientific information becomes available. Main problem with Cu as with many other products IMO, is overuse and misuse by irresponsible. unknowing, and uninformed users.

A very good idea for us all to think about the chemistry of things.

Here is a related point to Bill's comments from the presentation on fish nutrition from PBIV.

"Although vitamins and minerals are required in minute amounts compared with protein, lipid, and so forth, they are critically important, … Every micronutrient has a deficiency disease associated with it, the effects of which are sometimes irreversible or fatal. For a few vitamins and most minerals, excess can be equally detrimental, resulting in toxicity."

Whether it’s in the soil , water or fish food etc or in some product you add, it’s still chemistry in action. They are all part of the whole.

Cody's comments really have me concerned. Some of you might remember my efforts to clean the edges of my pond during last year's drought. I was able to pull debris from 12-15 feet out from the high water line.



My pond turned a bright green shortly after this effort, and stayed that way from about the middle of September until the end of April this year.

This has been the worst fishing season in the six years we've owned this property.

When we bought this property, the pond had a lot of very serious issues -- thick filamentous algae, lots of turbidity/mud, cattails, dozens of monster catfish, stunted bluegill, crappie, bass, . . .

I got my bluegill to trophy size -- and then it seemed to collapse last year.

During spawning this year, we did see lots of 10-12 inch bluegill and red-eared sunfish on the beds. We saw lots of YOY BG and LMB.

One thing that I hadn't considered was the many partial buckets of copper-based pond products we found in the basement and barns of the farm. Several years ago, I took all of these to the hazardous waste dump.

I thought that the absence of weeds was due to the grass carp and koi. I now believe it may have been due to massive dumping of copper based products to control the FA and other pond growth due to the heavy fertilization from the pastures and cattle feed areas above my pond. (This was one of the first control projects I started when we bought this property six years ago.)

The pond edge areas I graded last year, during the drought, now have lots of vegetation growing. Earlier in the season these areas were saturated with small bluegill and bass -- more than I've ever seen before. It seems like my white- and channel-catfish have successfully spawned for at least two seasons.

Fishing in the pond remains dismal. We have caught few fish since early May.

After reading the posts above, I now have a fear that there are hundreds of pounds of copper products in the bottom of my pond.

If so, what do I do now?

Thanks,
Ken

Hey Cat, I am not a chemist, but have read some on chelated metals.Cody's key word was "bound" copper. This is my take, and am probably only partly right, but maybe an expert will weigh in.Bound means to me that the copper molecule when bound, has "binded" with another molecule or molecules, causeing the copper molecule to no longer be broken down into a free molecule, thus the copper molecule is no longer able to move freely. When attached to another molecule, it is now "bound" and not able to move freely, kind of like having an anchor tied to it.I can only guess that previous to cleaning your edges, the copper had settled to the bottom, had organic matter and sediment on top of it, and was basically "bound". You stirred the pot.Probably a good research term for you is "chelated".It will give you better insight as to my layman's babblings. ( pronounced "key-lated")

I opened my warehouse of ignorance and spilled the contents for all to see. Cody I beleive is suggesting that copper sulfate is a bound Cu. To chelate means to be bound with another molecule. As I said....I was babbling....but hey I learned from my mistake!

During certain chemistries in the sediments bound metals can be released from the stable state. Hutchinson in his A Treatsie on Limnology touched on this topic. I am not a chemist and do not know all the specifics of the topic. More research needs to be conducted on the fate of Cu in aquatic habitats under varying conditions. A fisheries grad student at BGSU is looking into the lack of YP recruitment in a couple local municipal reservoirs - long term copper sulfate usage is one subject being investigated.

Boy I am having a hard time with this one trying to understand. Just tell me if you have aeration in the lake will it stur up the copper sulfate that was put in the lake? Will this stop the benificial weeds from growing?

It can do that.

That's why I mentioned in an earlier post, atrazine does not concern me as much as copper and aluminum (alum).

If I am getting this right this would be the only thing bad about aeration. That it would stur up the copper that is on the bottom. But the benifits of aeration would out weigh the negitive of the copper sulfate. If I am right this would also stur up the copper and would kill the algae if you would still have an algae problem. Makes you want to really think before you do anything with a lake. You will fix one problem an start another. I have always told my fellow lake members you can nudge mother nature but you can't force her you will get another problem.

Catmandoo - Did some reading and came across this at Mississippi U @ http://msucares.com/pubs/infosheets/is1334.htm (my italics)



So, my question is, would adding Ag Lime help? Along the same line, I also noticed that other industries use sodium bicarb.

A chelated form of copper like that found in cutrine plus is much safer and is not dependent on water hardness like copper sulfate.

I’m confused… I just checked the CutrinePlus warning label online and found this (italics are mine):



Is CuprinePlus not dependent on water hardness when controlling weeds even though the effect on fish is?

Be careful! All forms of copper can threaten fish and other aquatic organisms. The variable that influences the potential level of toxicity is the copper-concentration relative to the water's hardness (less copper is required for fish-toxicity in low-aklaline waters).
Chelated forms of copper seem to be more efficient for controlling algae (ie. good algae control with less elemental copper required). However, water hardness will reduce the activity of both chelated copper and copper sulfate - especially the later.

Kelly-
Would not adding AgLime to keep alkalinities above 300ppm (per mississippi u) alleviate Catmandoo's concern? Or, am I missing something here?

If I had trout I wouldn't use any copper at all, JMO. I called the company and asked to speak to someone who could answer a technical question concerning testing for water hardness prior to treatment. I wanted to check my water hardness prior to treatment for various reasons. One of my concerns was my dogs drinking the water, I breed labrador retrievers. I was amazed at the knowledge they had concerning specific conditions in dogs. If you have any concerns about the safety or effectiveness of cutrine, I would ask them. Their methods of chelation differs from some generic brands and they can explain how it is degraded.

Which concern?

How what is degraded? The copper in Cutrine?

Loretta, My lab got in my pond an hour after I sprayed some Cutrine Plus. I'm sure she drank some of the water while swimming-she always does. What did the Cutrine people tell you about the chemical and dogs?

Advanced reading about copper, copper sulfate, chelated copper (Cutrine and similar products,) and associated complexes:

http://www.mass.gov/agr/pesticides/aquatic/docs/copper.pdf

Bound forms of copper are less stable in acidic, anoxic sediments [u][/u]

Kelly,

I found Catmandoo's post thought provoking:


and


I believe he was referring to these comments:

and


Since dredging an entire pond seems to beyond the scope for most, I was wondering if keeping the "alkalinities" at or above 300ppm (per Miss U) through the addition of Ag Lime(?) would be reasonable (ie., the Cu that is present "deactivated")?

Bill-
Great resource -Miss U was the easy reader version! Seriously, though, a good read.

I don't think the alkalinities have to be as high as 300ppm(mg/L) to keep sediments saturated with Cu to a minimum. Well oxygenated conditions at the sediment water interface and alk at above 125mg/L IMO would do pretty good at Cu suppression. I am not a chemist but did play one on PBoss Forum.

Give Miz Cody's boy an Academy Award for his acting.