The weird green lake thing

[Santa]

Anyone know these?

I grew up by a lake and once a year huge amount of round green weedy things ranging from the size of pingpong to tennis balls would detach from the bottom and float to the surface .

THe texture of the weed would be very fine and mossy, it would have a hollow core filled with air or gas. If you squeezed it it would react like a sponge - and if you didn't it made a great missile ;o).

THere's a theory - possibly one by my biology freak uncle - that bubbles of methane gas from the rotting lake floor would attach to a stone covered with this soft mossy weed and become enveloped by it as it rolled with the waves or current. At some point seasonal changes in light and water clarity would make them all tear loose and surface.

I was told once that this phenomenon is restricted to only ten lakes in the world. And as the environment has changed over the years - it has come and gone.

THe local danish name for it is "gede-boller" which, charmingly, translates as "Goats' balls" or possibly and more appropriately "Pikes' balls". Bit of a double entendeur really.

What say you, crypto-biologists and lakelovers of the world?

 

[archman]

It's fairly routine for small lakes around the world to display seasonal bursts of submergent vegetation. Many species have lightweight and/or gelatinous anatomy, which can retain a great deal of internal gas volume (helps with buoyancy for the positive phototaxis).

There are so many species of aquatic plants, I hesitate to comment on the thing(s) growing in your particular lake. It could be a alga.

 

[Santa]

It's fairly routine for small lakes around the world to display seasonal bursts of submergent vegetation. Many species have lightweight and/or gelatinous anatomy, which can retain a great deal of internal gas volume (helps with buoyancy for the positive phototaxis).

There are so many species of aquatic plants, I hesitate to comment on the thing(s) growing in your particular lake. It could be a alga.

It definately would make sense for it to be some kind of algae considering the structure. The unique thing, or what I''ve never seen anywhere else, is the perfectly round shape. The presumed gas bubble would be about the size of a die in a tennisball-size specimen. That makes the material a couple of centimetres thick. It tears quite easily and looks the same all the way through.

 

[Fr3d]

Sounds like a form of green algae. A already mentioned various algae have air sacs to aid buoyancy and other processes. Really doubt it it a 'plant', but without seeing the actual organism I can't say for certain.

As for the theory, it sounds a little crazy too me lol

 

[Santa]

Sounds like a form of green algae. A already mentioned various algae have air sacs to aid buoyancy and other processes. Really doubt it it a 'plant', but without seeing the actual organism I can't say for certain.

Thanks for bothering )

Just spoke to my uncle again this christmas.

Apparently these things have started to pop up in a few shallow water, brackish saltwater bays as well. These tend to be very static environments that grow warm and smelly during summer.

Also, some years, he has seen them on the lake floor but they don't surface possibly because other algae (bright green, slimy stuff - I'm being very scientific here) steal the sunlight that is supposed to drive the process. (rereading this I find it smacks slightly of lovecraftian paranoia "They pop up everywhere these days, they're ... increasing their numbers!!!"

As for the theory, it sounds a little crazy too me lol

That's my mad enthusiast uncle for you (mad enthusiasts are really so much more colourful than mad scientists - their theories are not hampered by method and empirical considerations).

Anyhow it does seem more plausible to me that the circular shape with the gas core is just the way the thing naturally 'arranges' itself.

I shall try to get a digital picture of one come spring.

Note: They're not gelatinous in any way. They're firm and mossy and you can squeeze them dry like a sponge without destroying them. Sadly it makes them smaller and less impressive from a 'treasurehunting' point of view.