Algae Communities

[MikeM]

In a thread on another board several days ago, we were discussing algae on pond walls. The biofilm community, and nitrifiers in particular, get most of our attention... and for good reason. The algae community is of secondary importance to koi health, but it is important nonetheless. I think of it as an extra cushion of protection, consuming ammonia and nitrates, metals and other 'nutrient' in the water column. Algal cell walls are highly permeable. Water virtually flows through the cells, and in the process the algae removes some of the water's content; and the algae adds its own discharges of metabolic wastes, allelochemicals, hormones and such. The water is altered, conditioned if you will, as only algae can do.

Too much algae can be a hassle, and infestations of hair algae an absolute misery. When a mature community of short, filamentous algae is established, it gives me real pleasure. And, the koi like it too.

While doing a water change this morning, I took some photos of the algae on the pond walls. For the first few inches, where the surface can dry during water changes we see one sort of 'black algae'. Below that, a carpet of green algae that covers not only the walls, but also the bottom, 6 feet down.

[dick benbow]

So the one clump of algea turns to the other and says, "you don't suppose
Mike is up to something do you"? To which the other clump replies..."no, I really think he's beginning to see the light at the end of the tunnel"....!

[dOHd]

Mike

AS you mentioned, Algae is one of the most important aspects of the vast majority of ponds in the USA, and probably world wide. Without it most ponds would fail terribly, and very quickly too.

IF you take a sample of the algae on the walls, you will find all sorts of creatures, for the most part, going about life doing what they do best, consuming waste. The algae is their home and protects them.

In many cases the creatures large and small in that algae coat also use much more oxygen than do the fish we love to shower with O2. Both bacterial and larger lifeforms need the O2 as much as the fish.

So while most people take a one sided look at keeping their pond good enough for fish, the ones without problems always keep in mind what they are really doing is supporting the pond, which in turn supports the fish. The long term view.

Anyway, that is my take on algae.

d

[kingkong]

Nice crop. What material is the final coat of the pond the algae is growing on and how old is this crop? Oh, what is your koi population Mike? Do you have any plecos in there?

[MikeM]

KK: No plecos. Just koi... 20 in 12,500 gallons. 5 were acquired in March as tosai. The pond surfaces are polyurea spray-on liner over block. This is at 26 months.

The first colonizers were the simple non-filamentous types of algae. Small colonies of the 'carpet algae' began getting established after a few months. After about 10 months, some hair algae appeared, but it did not become rampant. It was on the wane last summer and disappeared altogether last Fall in the competition with the shorter types. (Of course, it always lingers in a pond, even if not seen.) Other parameters: no detectable ammonia/nitrite; nitrate typically below 5ppm; pH 7.8-8.0; Hardness 160-180 ppm. Oxygen is at saturation levels. Pond is under shadecloth and the shade of a large tree, receiving moderate direct sun in the afternoon when the angle of the sun is not overhead.

[kingkong]

Thanks Mike. I would like to purchase a "start" of that algae from you sometime. If you are ever thinking about it and have a host object with a culture growing on it...that would be great. Sure is a nice look.

[MikeM]

LOL... maybe I can put a rock in the pond to get a 'start' for you. Algae is not as ubiquitous as bacteria, but I think it will appear where conditions are right. Moi posted a photo of the algae growing in his pond. It is very different... more like a moss. I've borrowed his photo. It appears below. (Hope he does not mind.) His is a well-established pond, and the algae growth is light although in bright conditions. I've not seen growth such as his in an established pond before. The bright green is quite attractive.