Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Why do Big Lakes not have Filamentous Algae issue?

Why do Large Lakes not get Filamentous Algae problems like smaller ponds? Just had a 1 hr discussion with one of my good friends on this topic. Anyone want to chime in?

What's the cut off between a large and small lake? Would it have something to do with wind being able to move more water on a large lake than a pond, which would be more susceptible to more stagnant water that filamentous algae might have more a tendency to be more prevalent in? Or is it there, but because of it's large size, it's dissipated and not as obvious to an observer?

Wind and waves?

Edit by me: Omaha, we hit at same time

Ok.. Not to be Devil’s Advocate here.. but If it was water movement than why am I always scraping it off waterfalls … Why is it a problem in some Springs and rivers..

I never see it in rivers around here so I can't attest to that. But waterfalls, possibly it's a consistency thing. I'm just throwing darts at this point, I have no idea. But if similar water and oxygen are hitting the same area, possibly that increases the chances of the algae sticking around. Again, just guessing...and desperately waiting for someone who knows what they're talking about to come along.

Currents.

I was thinking more along the lines of aeration.

For it being such a cooler water lover I don't see it much around here. It seems to me it needs lots of sunlight and little fertility. But I am kind of like Omaha and just tossing stuff out there.

That being said I don't see it at all in northern crystal clear lakes. I'm confusing myself

Typically lower fish densities hence lower addition of nutrients and phosphorus
Typically lower nitrate levels that fuel algae growth due to more phytoplankton numbers to compete with FA
Typically less shallow area FA need for light penetration (littoral zone)
Potentially more competition for nitrates by macrophytes
Potential more areas of denitrification that change nitrates to nitrogen gas (anoxic deeper water)
Larger water more dilution of nutrients and phosphorus
More stable water chemistry
More surface area for better circulation and D.O. levels
Lakes tend to be less eutrophic than pond with exceptions of course

May be on to something with it being Nitrogen limiting not Phosphorus limiting... but very shallow lakes that are hypereutrophic have no vegitation...Lake St. Marys-Ohio, Lake Apopka-Florida, Kokomo Reservoir-Indiana all are very shallow with average depths, I bet less than 6 ft… all have no filamentous algae…All have planktonic/Blue green Algae blooms

Good topic Matt. Cecil's reasons are a lot of the probable contributing reasons IMO. Different variables will combine to cause or hinder dense filamentous algae growths. Kokomo Res is usually turbid (sediment) with reduced light penetration, murky water - lack of light is a big factor there IMO. What are average water clarities in Lk Apopka? Grand Lake St Marys has lots of shallows, low average depths (alot of it is 6') with abundant ski boat traffic and wind action that keeps it stirred up and quite turbid which is why the alum treatments did not work very well - too much resuspension of sediments. I suspected that would happen. Alum works best in deep lakes with minimial resuspension of settled floc. Hypereutrophic usually has dense blooms due to higher P concentration. Dense blooms limit light penetration.

In clear waters usually macrophytes use a lot of the nutrients competing against phytoplankton and filamentous. Filamentous algae (cold-cool water forms), periphyton, or minor phyto blooms will sometimes develop growths in early spring in clearer lakes until the macrophytes get growing, then the filamentous algae gets starved and dies out. As the filamentous decays the macrophytes consume most of those nutrients. This pattern is noted in Welch's limnology texts and it also occurs in my pond with filamentous taxa and macrophytes.

Different filamentous species prefer different nutrient concentrations. Cladophora is considered a P hog.

Yes the algae blooms out compete the filamentous algae but like Bill says they can be quite turbid too from time to time in colloidal clays from what I've heard. Lots of farm run off in those areas.

Wow I got some really anemic bass and crappie to mount out of Lake St. Mary's-Ohio once. Really sad!

We had a place on 88 acre Round Lake in north central Indiana. The lake was shallow and very clear and had a lot of weeds but I don't remember any FA. Some people did use copper sulfate to control weeds in their lake front. I was always told that runoff from nearby farms cause the weed problems. There was about 5 acres of solid weeds a ways out in the lake that actually looked like land. No boats could penetrate this area but I had an asymmetric catamaran sail boat that didn't need dagger boards to sail and so I could lift the rudders and go right through the thick weeds.

John,

Which Round Lake was that? What was the nearest town?

Matt:

Late to the discussion here but here's my take:

I believe it's a combination of things, not one thing specific. Nutrient loading and water clarity.

I agree that it's not current, as I have to treat man-made streams/waterfalls for Filamentous Algae (FA) too.

It will be interesting to see what happens to the local lake this year. They treated it with Fluridone last year (all 365 acres of it) for Eurasian Water Milfoil and Curly Leaf Pondweed. Typically the majority of the shoreline out to 200' would be completely choked off by EWM, and if the water clarity allowed it, CLPW would grow in water up to 12' deep.

After the lake was treated, the lake had it's typical algae bloom and all was good. We'll see if FA shows up this Spring.

Wow I wonder how much that cost!

50% was funded by a Fed grant.

Remember the original question was about large bodies of water. Nutrients – primarily nitrogen and phosphorus – when in excess are directly available and allow normal background levels of algae to grow into excessive blooms. The currents in large bodies of water will distribute and dilute the Nutrients (primarily nitrogen and phosphorus) levels with less Nutrient rich waters in the impoundment. This is why you can find isolated areas with FA problems on a large lake and not have a overall FA problem. These isolated areas tend to not have enough current or less nutrient rich waters to dilute the nutrient level in those isolated areas. Also note that you can find areas where inflows of high nutrient water can cause problems in the same lake (say near a sewage discharge where the nutrient levels remain to high.

The streams, rivers & waterfalls you are encountering (while they have current) do not have this dilution process that big lakes do to prevent the FA problems.

If statement is wrong on this I will defer the blame back to my marine biology professors at Troy University. I am only passing along some of my teachings as I was trained back in the day and realize things do change. If I had not answered from my phone I would have explained why my answer was currents in more detail the other evening.

Tums, I agree with your previous post. One lake comes to mind where a drainage ditch empties into the lake after running thru numerous farm fields and pastures. It dumps into a small bay, and that area is usually packed pretty well with FA. Once the bay opens out into the lake, the FA doesn't grow.

40 years ago that bay was 10' deep near where the ditch entered the lake. Now it has less than 24" of water in that area when the lake is at it's normal level.

Cecil this Round Lake was roughly 7 miles north of Columbia City and was connected to Little Cedar and Big Cedar lakes, The Tri-Lakes.

How about a geometric possibility?

Is it possible that large ponds have relatively lower percentage of shoreline to surface area? Assuming that most of the FA grows along the shoreline where the water is shallower???

Take a circular pond for example... A pond with a radius of 100' has a circumference (shoreline) of about 6000' (2xPixR) and a surface area of about 30,000 sq. ft. (PixRxR). A pond with a radius of 1000' has a circumference of 60000' and surface area of about 3,000,000 sq. ft.

The area grows at a 10 to 1 ratio of the circumference in my example.

Any validity?

Geometric can play a role. Geometric (morphometry) will have a big influence on how bad or massive the problem gets. I always say the plant problems occur most in shallow water not in the deep middle areas of the pond.

Numerous variables can contribute to filamentous growths, but it will not grow if the nitrogen phosphorus ratio and light are not optimum for that specie of filamentous, no matter what the other factors are. Thus nutriens and light are the most important factors, others are seconday or lesser importance.

Once you start studying the filamentous algae you realize there are many different species. Each species no doubt prefers a unique nutrient P:N ratio and growing conditions. Similarily not all fish Be careful in lumping the ecological requirements (ethology) of all filamentous algae into one group.

O.K. China paid for half of it indirectly.

Have worked on reservoirs from 300 ac to 100k+ ac in the southeast, varying trophic levels from oligotrophic to hypereutrophic. Highly complex systems influenced by age (influences depth, nutrient levels), inflow/outflow (landscape drainage, annual rainfall, hydroelectric manipulation), morphology (fetch a big player), trophic status, and fish species present. I'd say soil types, nutrient levels and cycles, and fetch the dominant players in FA occurrence. Fairly common to see small patches of various FA in secluded areas during spring and fall in nearly all trophic levels. Large populations of rough fish e.g.common carp also figure into the mix of many variables.

Based on the shore of Lake Ontario in almost any time of year, that is not true. Gobs of disgusting FA always floating up on shore with plenty of other nasties. This is mostly due to processed sewage being dumped into the lake well offshore providing for more than enough nutrients for FA to form.