Floating brown stuff in the Soar

[Brick]

There is now strange brown stuff floating in the River Soar again. I've had the misfortune to have had a close encounter with it last year, and it's some brown, really thick "stuff" that floats. There are really big clumps of it further down the river, and in a canalised part of the river, there are much smaller bits of it floating. Further up, there's none. And there's no obvious source for it that I can see.

What is this stuff? It's existence is one of the reasons I demurred when Wildie suggested I could establish a precedent by swimming in the Soar at Abbey Park.

Without knowing what it is, it's really off-putting. Any ideas what it is?

[proud2bwelsh]

Brick, my research on the web has led me to this. However I think I'm wrong. The stuff on the website doesn't make allot of sense really, one part of it says it sinks, and the other says it mixed up according to the turbidity.

Diatom - a type of algae (http://en.wikipedia.org/wiki/Diatom)

Most diatom species are non-motile but some are capable of an oozing motion. As their relatively dense cell walls cause them to readily sink, planktonic forms in open water usually rely on turbulent mixing of the upper layers by the wind to keep them suspended in sunlit surface waters. Some species actively regulate their buoyancy with intracellular lipids to counter sinking.

[Brick]

I've had a look around on pages discussing diatoms, and I can't find evidence of floating clumps of it. Yet.

Algae can form clumps, it seems:

http://www.pondmill.com/en/management_surface_water.html#algea

Although what I see is brown, the closest thing to what I see on this page is floating clumps of dead green algae Ulothrix on this photo page:

http://healthvermont.gov/enviro/bg_algae/photos.aspx

The description says that the clumps appear when the temperature rises and the algae breaks off the rocks. That would be consistent with the timing, as it appeared as the temperature rose over the last two weeks or so. But what I see is completely brown, not a mix of green and brown as described.

[Wildswimmer]

It's the brown sausages gift-wrapped in tissue (aka Admiral Browns) that you should be concerned about, not really anything else. Fortunately Admiral Browns are now a very, very rare occurrence and generally only escape from sewage plants overloaded by storm water (when as the river would be in spate you shouldn't swim in it anyway).

I've noticed the brown clumps in all rivers I've swum in - they are perfectly natural and harmless. Brick, you do seem unusually concerned over the quality of open water. If I were there I wouldn't think twice about jumping into your rivers - irrespective of colour, unidentified floating objects, or temperature. I've been swimming outdoors for nearly forty years, and started when rivers were a lot dirtier than now. Yet I've never caught any illness from open water. If you're concerned about the cleanliness of the water, just do head-up and don't swallow any.

Back in the Sixties when crossing the Mersey by ferry one used to see shoals of what were euphemistically called "Mersey salmon": rubber items with a knot at one end. Now the only Mersey salmon you'll see are large, silvery, have fins, and taste nice.

Wildswimmer Pete

[Brick]

I think I've said before that I now feel a bit more concerned about water quality and various unknowns, while in childhood I quite happily waded out past the floating algae mats in Lake Pupuke and swam, or waded out through the stinky black mud in Blockhouse Bay, to swim. I think I need to get used to this sort of thing again, and think it'll be easier to start with the easier locations, than to jump straight in to the slime and rubbish. Even if said slime and rubbish is actually harmless.

Interestingly enough, the River Soar used to be infinitely more polluted than it is now. It was famously pink from the dyes used in textile manufacture. And I'm told that 10-20 years ago you could more or less "walk across it". But back then was when people used to swim in Abbey Park with the encouragement of the council, while today nobody swims there at all (I don't really count the people jumping off bridges).

There are people even more fussy than me. One person from the triathlon club told me that we'd also be training in Bosworth Water, where the water is much clearer than King Lear's lake, which is a bit cloudy and "yuk". I expressed surprise as I'd visited KLL the previous day, and while cloudy, it looked a "normal" cloudiness, and an excellent place to swim.

[Juicy Lucy]

It's the brown sausages gift-wrapped in tissue (aka Admiral Browns) that you should be concerned about,.... If you're concerned about the cleanliness of the water, just do head-up and don't swallow any.

Back in the Sixties when crossing the Mersey by ferry one used to see shoals of what were euphemistically called "Mersey salmon": rubber items with a knot at one end.

Wildy, you certainly know how to stop people from entering open water events.

I'll never go in after reading this. Thanks.

JL

[Brick]

This morning I took another route into work where I cycled over a large weir. [Over a bridge raised above the weir that is]. That weir has a lot of green algae growing on it. Near the weir there were large floating mats of "the brown stuff". But I could see that it was more green than elsewhere, and that it was in a more filamentous state.

So, I think that solves the mystery of the floating brown stuff. The algae that lines the canal further up is more brown, and shorter, than that growing on that weir. That, I presume, explains the change of colour.

Before I started reading up on this stuff, I wasn't aware that some of the surface scums found in natural water are actually pollen.

It seems to me that the take-home lesson here is that perhaps some of the public's view of natural water as being "filthy" is due to not knowing that some potentially "unattractive" looking features of the water are actually natural. And not a symptom of "dirt".

[Wildswimmer]

But I could see that it was more green than elsewhere, and that it was in a more filamentous state.

The filamentous stuff was probably that favourite set piece of biology teachers everywhere: spirogyra. When I was a kid we were forever wading about in streams collecting the stuff (of course the H&S Gestapo weren't around then). It's completely harmless and those bubbles of gas often seen within clumps of spirogyra are in fact oxygen. It's a major oxygenator of open water.


Before I started reading up on this stuff, I wasn't aware that some of the surface scums found in natural water are actually pollen.

The pollen films on Hatchmere are frequently brown mottled with white. Most unattractive looking but completely harmless. The appearance of pollen scum will vary according to the composition of local flora.

It seems to me that the take-home lesson here is that perhaps some of the public's view of natural water as being "filthy" is due to not knowing that some potentially "unattractive" looking features of the water are actually natural. And not a symptom of "dirt".

Much encouraged by the likes of RoSPA. However the tide is turning (groan :rolleyes:). According to a recent Government survey participation in open water swimming is increasing faster than any other outdoor water sport.

Wildswimmer Pete