Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Cold tolerant FA species?

Hello PB gang. I had a new occurrence at our pond this spring. Normally, any living FA mats we see in the fall are killed with frost/freezing and ice formation. So in the spring we start with clean edges on the pond. This past fall, I noticed the FA mats didn't seem to die with the fall freeze, and could actually see FA on the surface and frozen in the ice this year, which was a new thing. Then at ice off, those same FA mats didn't sink and are (mostly) greening back up. So instead of a clean edge to start the spring, we already have 30% edge coverage or more. Very disappointing way to start the spring. We have a very old (eutrophic) pond, and always fight FA. However, we've learned to get pond dye in at ice off, and keep adding every month or so, to cut down light penetration in the shallow edges. This helps to a degree. We then put down copper granules around the edges right away, to hit the FA mats that appear on the bottom, before they get growing and any surface mats form. Next, we use liquid cutrine plus to spray any surface mats that do appear, and repeat this about monthly. With this combo, we can keep our edges fairly clean (not perfect, but not much FA). After reading a bit and working the PB forum archives/threads, I am worried we have developed a copper resistance and/or cold resistant strain of FA. Anyone with experience with something similar?
I am hope Bill Cody will see this post and chime in. I almost just direct messaged him, but posted my question instead, so any possible solutions could be shared with everyone.

Unrelated side note, saw 7 wood ducks on the pond this morning! I have our duck boxes re-set and ready for takers. I might try and stream from our duck box with the camera again this year.

I have seen FA during the winter in Oklahoma ponds. Usually a much different set of circumstances.

If you are constantly battling FA, I would get the Phosphorus level checked in your water. That is most likely the catalyst for FA growth.

I have no doubt of phosphorus and nitrates. We (unfortunately) have over 60 acres of run off from row crop Ag fields flowing into our pond. I do have two small silt catch ponds, but both are heavily silted in from many years of run off. It would be ideal to have both cleaned out and even deepened. However, my pond budget isn't large enough for this job. As many PB members are aware, moving dirt is pricey. And then having a place to dump the silt, to dry and turn and dry is also a challenge.

So you are completely correct. I hate to admit it, but I find myself doing 'California Forest management' on my pond. Even though I know the best and proper way to address the issue, I instead just treat the end results of my poor management choices. But I suppose we all do the best we can with the options in front of us, eh?

Congrats on your wood duck arrivals. I always enjoy your posts showing them thriving at your place!

As to the FA doing better over the winter this year, there are many, many possible causes.

If it was a new pond, I would expect that the age-related, inevitable increase in captured nutrients caused the change. However, for an old pond it is less likely that you finally, and permanently crossed some important threshold.

In my (non-expert) opinion, it was probably some random weather-related event that helped your FA survive through the winter. For example, perhaps you got heavy rains that occurred right after the fertilizer was applied to your adjacent ag lands, and you therefore received an extra "dose" of fertilizer.

Unfortunately, if no FA is ever physically removed from your watershed, then even after your spring treatments this year, those extra nutrients will still remain in your pond.

I would follow your regular spring protocols, and if you do get some heavy mats, maybe pull some out and deposit them outside of your watershed basin that feeds your pond.

Also, maybe add a few more FA combat protocols. Can you put in some tilapia if you can get a split load from a PB buddy in your area? Can you plant some attractive emergent plants that will steal some of the nutrients from the FA? My wife likes that one, and says she would do most of the care if I can ever get my ponds re-done. There are several other reasonably priced options in the FA threads.

(I don't know about cold-tolerant FA. Perhaps our plant experts will know. However, once established, I think your eradication efforts would probably be very similar to normal FA procedures?)

Good luck on your efforts to have a nice pond this warm season!

Over the years, and every year, we've raked out many many bucket loads of FA mats. We pile them with our leaf pile and let them break down. Makes some killer garden box soil after a couple seasons. I don't know if there has been a net reduction of nutrients, but a fella can dream..

I looked into tilapia big time a few years back. Unfortunately for me, the state has taken the position that tilapia are 'no bueno' for Iowa, due to being a 'potential invasive species'. This is despite the fact they can't survive our winters, and that our neighboring states allow them. But you've inspired me to write another letter to my state rep about it. Might also call the state fisheries biologist again.

I also tried to plant some water lettuce starts I bought on-line from a place in Wisconsin. I can't see any evidence they took hold. However, that would also be worth trying again, maybe inside a protective cage with closer monitoring. I did move some American pond weed from our silt ponds into the big pond, and that did take, but only in a couple places. I have not dabbled with the emergents, but also think that's a great idea. I know there are some water loving iris species that are pretty cool. We have a lot of iris beds, and love the flowers and the lack of need for much care.

I appreciate the suggestions!

The water iris is definitely one of the plants that my wife wants for some of our pond edges. I believe they spread very slowly.

I did have one other thought, since you have upslope silt ponds. You could plant something that spreads rapidly in those ponds in the hopes that plant takes up a significant load of the nutrients.

I suspect that would only work for smaller rain events, where the incoming water does little more than displace the existing water in your catch ponds. Also, you would definitely have to pick a plant that does not spread by seeds or broken pieces of the plant - since you don't want it in your main pond. Our plant experts might have some proper candidates.

As a bonus, a thick mat of plants in your silt ponds would more effectively catch silt and keep a bit more out of your main pond. Of course your silt ponds would then fill in even faster.

I do not know the size of your silt ponds, but renting a mini-excavator for the weekend is pretty cheap. The biggest minis have a decent reach. Further, if your pond bottoms are solid and the slope is gentle, then you can drive into shallow water and operate.

I also don't know how far you need to "throw" your excavated material to keep it above the flood line for heavy rains? If you can get by just rotating and dumping the bucket and then later spreading the spoils a little bit up-slope, then you could probably renovate your silt ponds yourself.

You could look into using Phoslock as a more feasible option.

No concern about one of those rapidly growing plants upstream relocating into the main pond?

Definitely a big concern!

That is why I listed at least two of the requirements for safety against spreading.

Perhaps no plant meets those requirements?

I hope Bill sees this. I'd love to know what temp ranges the different FA species have.

We've done some thinking about planting 'something' in the silt ponds, to catch nutrients, but every high water event fills them completely and then washes stuff into the main pond via the overflow ditches. As you noted, I still can't settle on a species that wouldn't take hold and maybe run wild in the main pond. I learned long ago that my 'control' over the pond is tenuous at best.

We've looked into renting a mini X and play small ball with excavating the silt ponds. My brother-in-law even volunteered to operate it (he's got lots of work experience with excavators). The Boss says I'd need to haul it 'somewhere' and not just pile it to haul later. I'd need to purchase a small dump trailer to make that work. I put that request in to The Boss, but so far it's been slid down the list below silly stuff like new windows on the house, replacement deck boarding, a swim spa for the afore mentioned Boss, and groceries. :-)

I did a bit of research on nitrogen mitigation via floating plant islands. The roots grow down through the island into the water, and periphyton grows on the roots, and then consume the nitrogen. There are even commercial places the sell them. I think maybe I could build something, but it might be a push on the cost vs just buying one? Not sure how I'd gauge success. Maybe serial water tests before and after?

Topic: "" Nutrients and siltation from over 60 acres of run off from row crop Ag fields flowing into our pond.""

You are in a tough place managing a pond with constant incoming agri-nutrients. This creates a BIG plant problem for a pond. Been there done that. As you know nutrients grow good row crops and when those nutrients are in your pond they do the same thing to grow bigtime crops of pond algae & plants. As long as the watershed feeds the pond and remain in the pond, the pond will want to grow a plethora of green stuff. By continually suppressing the FA you are allowing an accumulation of a bigger and bigger total nutrient sink accumulation to develop in the pond. This will cause the pond to want to respectively grow more and more green as time passes. What grows is basically determined by the historically accumulated and fresh input load of nutrients.

If the pond water is usually clear (4-5ft+) the balance of N:P is favoring FA and not phytoplankton. Some forms or types of FA are known Phosphorus Hogs. High amounts of phytoplankton will usually shade the water enough and starve the FA to a point that FA would be suppressed. If the water has low visibility due to silt turbidity, then the nutrient load is very high to create overloads of FA from just the shallow illuminated area / zone of turbid water while noticeably less or none grow in deeper low light areas.

Since we do not know the specific type of FA that is causing the problem, we do not know if the current type is the same specie/s ? type that was prevalent in earlier years. Constantly suppressing the FA with the same annual procedure likely allows the FA to adapt and/or resort to or develop a new introduced specie to the same old treatment methods or it could form a more tolerant strain or type of FA.

I had a very similar pond originally built that received similar agri-runoff. I then rebuilt the 35 yr old pond and rerouted the inlet water. This noticeably reduced a lot of my pond problems. In your situation, I would explore various methods of nutrient abetment for ways to consume and bind excess nutrients that would could be bound then ideally be removed. IMO some form of plant excess growth will always occur and need to be dealt with as long as the high inflow of agricultural nutrients annually enters the pond.

Once nutrients are introduced into a non-flow through pond some sort of harvest or binding is about the only way nutrients can be actually removed. Compare the amount of agri-harvest used on the 60acre watershed and then transfer a similar amount of needed crop harvest work for the respective acreage of your pond.

IMO constant, regular, and continual chemical binding of a constant high input of nutrients is or will eventually be detrimental to the pond ecosystem as a whole.

Floating plant islands are a good non-algaecide possibility, however with the high annual nutrient input to the pond a lot of island surface area would be needed to see a good impact. Homework needed for island surface area vs nutrient load/s. Nature demands that something will utilize the available nutrients. I would check with the floating island's Bruce Kania to see if they harvest any plant materials from their floating islands other than harvesting just fish as their form of nutrient removal / abatement. Bob Lusk has been associated with Bruce Kania for a few of the PB mag articles. There are several good videos on Youtube for building low cost large floating islands.

I really appreciate your input sir!