Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Green Layer on Pond

Hello, we are in California. We have a small pond that seems to be having some issues. I'll try to brief the timeline...

Originally we had alot of tadpoles, frogs, mosquito fish, bluegill/sunfish, crappy, and channel cats. We stock it with 500lbs of trout every April right before the water heats up.

These days we are mostly down to just year round channel cats and we stock it with trout once a year still. There are traces of the other life in their but not very abundant.

A couple years ago we stocked the pond and the trout didn't make it. They are from high altitudes though and we are not. So we had guessed it was that the water was a tinge to warm or not enough oxygen.

This April we stocked the pond but we threw a giant pump in their to put more oxygen into the water. This really had 1/4 the water in our pond really bouncing... The majority of the trout made it though : )

As we got into the summer and removed the pump then the pond began getting a real lime green color. Pretty close to around the time the trees were dropping pollen so we had assumed maybe it was caused from tree pollen.

Rather then relying on our springs we started running a tiny bit of water into it to try and dilute it or something.

As the rain etc started then the lime green color deluted mostly.

Now we have had this green layer floating around on the pond that doesn't seem to be going away. It's a really grainy look to it. I haven't touched it but it doesn't look slimmy or weedy like typical pond scum. Is there any ideas of what this could be and how to get rid of it? Also if it's harmful in any way?

Thanks and sorry the picts are kind of blurry... I chose splotchy areas to try and get a good picture of it but it's more of a solid film in most areas. We also have ducks and have had tons of Canadian geese around (although the geese don't go in the water rarely).

Welcome. Can you take a better sharper picture the floating material? It could be an algae or maybe duckweed or water meal? If it is an algae all we can do is guess what type it is unless someone looks at it with a microscope to identify the group or genus. I do that sort of thing if you are interested to know exactly what that floating stuff is.

Regarding the trout, why not stock them in the fall as soon as the water temperature drops to the mid60F range?. They will grow in fall and winter and be larger in spring when you can fish for them until they die when water gets too warm for them (>72F). If you are not feeding the channel cats the older, larger ones may be eating all the smaller invertebrates and smaller fish. Do you catch and remove any catfish?

Ok, I'll try to take a sharper picture tomorrow when it's light out and we'll go from there...

We don't stock the pond in the fall because we have heron's etc that crowd around as if it's a buffet. They go through the trout really fast. We stock the pond in April because the water is typically still very cold and it's right when our customers come to fish it. The trout usually last until July before they are fished or eaten out by other things.

We don't remove the catfish because our customers love to feed them year round. They are very large and the tamest you'll see. They are pretty much our parks pets... (as odd as that sounds. Especially being a sucker fish...LOL)

I don't believe the other fish have died because of this green stuff. I believe the cat fish and herons ate them or they were fished. I'm just worried that maybe we are getting this green stuff because we don't have enough little fish to keep the pond clean enough?

The google images I've found it does look alot like water meal or duckweed. Looks similar to some Microcystis (whatever that is) images too? Algae seems to look to thick and slimy IMO but maybe.

Again, I'll take more picts tomorrow. Thanks!

Okay - your added information helped a lot. Numerous large catfish will consume lots of smaller fish. A big catfish can eat a pretty large fish. If it will fit in their wide mouth, they will likely eat it. Large catfish has a big mouth opening.

Contrary to some beliefs, little fish will not keep the green stuff under control and keep the pond clean - an old wives tale that persists with some. The recent occurrence of floating green stuff is very likely a sign of added or progressive nutrient accumulation and added enrichment from feeding the fish.

Where in Ca. are you located? With the diversity in the state, the water could run from warm during the summer like the Salton Sea or the Imperial Valley to frozen over half of the year like up near Mammoth Lakes.

How big is the pond, and how deep does it get?

We only feed the cat fish a few times a year with actual fish food pellets. Otherwise we will toss a few loafs of bread to them every few days.

The pond is 20 years old. It started as a mud hole with bull frogs but we dug it out with bull dozers till we got good water sprouting from the springs in the bottom. Now I'd guess its about 20 feet deep in the deepest points. I also believe the springs are probably alot less active now as lots of muddy water from ditches etc flows in their and has settled on the bottom making it less deep over the years.

Only water running into it is from ditches and a freeway ditch runoff (unfortunately). There is no mountain water running into it or anything.

We are just below tahoe in the foothills. 1400 ft. I've took a picture of about half the pond in the images below so picture it a little over twice that size.

In these pictures I start zoomed out and zoom in alot. It looks grainy until zoomed in even more then it kind of looks like little grass seeds in the pictures. I still haven't touched it but it doesn't look slimmy. Although if you look at one of the images zoomed it and some of the green is on a stick... it looks like it slimes once it's actually on something. I've also just notices these leaves that it appears it dried on. I'm not positive its the same stuff but I'm 98% sure. Kind of looks like paint? Hopefully this helps identify... Thanks!


I can post the larger versions of these images if needed. I was just trying to avoid forum picture pollution...LOL.

Pictures of the stuff in the water are out of focus. The leaves and stuff on them are in good focus. You could have two types; stuff on the leaves and the floating spindle shaped clumps. Maybe try to put some of the floating stuff in a dish or pan and get a picture? One good sharp picture is enough.

To add to what Bill said, plants usually show up with good definition when a single plant or stalk is placed on white paper, not a clump of plants.

I've been working a little on this algae film problem. I think, as I first suspected, it is a growth form of a common bluegreen algae called Aphanizomeon flos-aquae. It doesn't normally grow exactly like that pictured above but at times it will look like this. Cecil will be along shortly and post a picture of 3 examples of A.flos-aquae that appear like the algae above from JLS.

Ok, tried again. It is REALLY hard to get a focused picture of this stuff. Especially since I'm dancing around it like a fool thinking it could be E Coli. Anyways, I've tried again but still don't know if these pictures are good enough. I pulled it out of the water this time... Our camera just isn't powerful enough I think.

The stuff on the leaves really looks like paint but after inspection from me and a couple others we fully believe that it is the same thing. I'm not sure how as it looks totally different but the stuff is on the leaves because it's raining like crazy out here and the water rose... when the water dropped back down because it's getting released by our overflow it left those leaves everywhere the water reached.

Unless the water itself is causing the leaves to be that color but that doesn't make sense either as the water is clear to muddy clear looking in these areas. Not green... only floating green stuff.

Here are the links. Click on the images to zoom in. The images should be huge...

http://img227.imageshack.us/img227/8780/pondclose2.jpg

http://img442.imageshack.us/img442/885/pondclose.jpg

How hard is it, how quick is it, and how much would it cost to have you test this if we can't figure it out?

It is not E.coli and will not make you sick unless you eat a gallon of it. I will look at it for free. Just contact me for collection and shipping info. For preserving you will need some iodine based skin cleanser available over the counter in pharmacy.
JLS - check your Pond Boss Private messages (in My Stuff) for sending algae to me.

O.K. here is what Bill wanted me to post:

Growth form of Aphanizomenon flos-aquae a bluegreen algae (Cyanobacteria) that commonly forms surface films.

I agree with Bill - probably a type of BG algae. The good news is that it is not DW or WM.

In the cause area note also that churning up the bottom by catfish , pumped water or whatever causes the settled nutrients to come back into and available for plant use including BG algae.

Hopefully one of these links will stay up for a while.

Blue-Green Algae May Fight Lou Gehrig's Disease -- MP3 Audio

Blue-green algae used for treating Lou Gehrig's disease in mice model

Anyway, quite interesting. Time to go swimming in our ponds!

Cody Note: Spirulina (individuals shaped like a coiled spring), the subject of the above bluegreen research, to my knowledge is not all that common in ponds. I have never seen it more abundant than 'scarce' in ponds. I am not sure what causes it to be a dominant player in pond habitats. There are numerous species of Spirulina; both in fresh and apparently some salt water. I don't think it forms surface films and is mostly a suspended or planktonic algae. Someone correct me if I am wrong. So if you have a surface film, one can eliminate Spirulina as the offending bluegreen genus.
Several of the bluegreen algae cause big time nuisance problems in ponds. The species developed for some reason, it would be a 'strange twist' if one or two of these nuisance offending bluegreen species could provide a cure for some of the terrible human diseases. Maybe there is a God directed plan and we haven't figured much about that plan yet.

http://protist.i.hosei.ac.jp/PDB/Images/prokaryotes/Oscillatoriaceae/Spirulina_2.html