06-10-2013, 05:23 PM
Re: Dydimo spread not due to felt soled boots?
"The native distribution of D. geminata is the cool temperate regions of the Northern Hemisphere, including the rivers of northern forests and alpine regions of Europe, Asia and parts of North America. Until its recent discovery in New Zealand, where it was introduced, it was never previously found in the Southern Hemisphere. The distribution of didymo in the last two decades appears to be gradually expanding outside its native range. Even within its native range, there have been reports of excessive growths in areas where it previously existed only in low concentrations."
Originally Posted by Flyfisher for men
This was from one of silvercreek's posts (not trying to pick on him by any means).
It does raise some questions, though, of why and how those blooms are taking place now.
Presumably, if the low phosphorus has been a constant for many years in New Zealand, why are we suddenly start seeing blooms there now?
Also, if you look to North America in its earliest days when there was little use of fertilizer, then didymo, all else being equal, would have been present, then declined as fertilizers came into use. Anyone know anything about the historical record?
I think without question dydimo spread to NZ, probably on the equipment of fishermen. So my supposition is that the blooms there are the result of recent contamination.
North America is a totally different. Dydimo is a "native species" and has been here for many decades and presumably been spread during that time. My guess
is that the use of chemical fertilizers was well established before the major spread of dydimo and/or the limnology of the bulk of the rivers in NA differs from NZ.
The question is not whether dydimo can be spread by wading boot felt, laces, fabric boot facing, neoprene, wader fabric, and flies, etc. I think it can. The question is whether the banning of felt to prevent spread is an effective strategy when dydimo has had decades to spread to every fresh water system that can support it.
---------- Post added at 05:23 PM ---------- Previous post was at 05:14 PM ----------
Originally Posted by silver creek
Were they New Zealand Mud Snails?
Honestly don't know the answer to that question, but do remember one reference to them as 'Zebra Snails.' Shells in the one printed picture was a no brainier to see the stripes. No idea if that's of any help.
I think they were Zebra Mussels.
They attach to boats and motors, hence the inspection that found them
They are a bad invasive. We have them in the Great Lakes and utilities spend million of dollar to clear clogged water intake pipes.
"Discovery consists of seeing what everybody has seen and thinking what nobody has thought"..........Szent-Gyorgy