New Info about didymo

[Chaz]

I first heard about this in March, but this is the first time I've actually found info on it. Keep in mind this is an attendees interpatation of what was presented.

Didymo

 

[afishinado]

Great info! Thanks for posting, Chaz.

 

[mikesl]

Excellent read, thanks

 

[geebee]

i read somewhere that one winter a stream was treated with Phosphorus and the Didymo never came back.

 

[Fishidiot]

Yep - good read. Thanks Chaz.

Although I've long suspected that didymo is present in many more waterways than we're currently aware of.......I didn't know the connection between snot and phosphorus rates. It does make sense.

 

[greenghost]

"Examination of lake sediments by Dr. Sarah Spaulding show that didymo has been present for more than 10,000 years and there is strong evidence that there were historic bloom events prior to any human activity."

This is surprising. I always thought it was an invasive species. Apparently not. Only in a few waters.

 

[krayfish]

Interesting read. I'll venture a guess that it's on many streams...we just haven't found it yet. I saw it in one section of the upper EB a few years back and it was like nothing you've ever seen before. It was about a 1/3 mile long with a 12-18" thick blanket on the bottom. You couldn't see anything but rock snot. Hopefully a phosphorus treatment can control it without harming the rest of the ecosystem.

 

[Chaz]

As the Phosphorus decreaes the didymo starts growing stalks or straw. And it only occurs in cold water stream with good water quality.

 

[nymphingmaniac]

yeah you have to read the part about phosphorous carefully and follow up by reading other sources. low phosphorous produces stalk growth, which is a dormant state of the organism and it no longer divides (making new cells). This is a typical nutrient deprivation response observed in many microorganisms. So low P, actually CAN reduce the number of didymo cells in a waterway.
Low P causes stalk formation. The current hypothesis is that the mat caused by stalk formation is a type of structure like biofilms that are made by bacteria and fungi (part of what makes pathogenic microbes hard to treat)- a phrase used to describe it is microbial communities. Scientists think that the mat formation is important for didymo to survive in low nutrient waters. A clue why was discovered by the analysis of bacteria and other microbes growing in the mat. Scientists found that these bacteria act in a symbiotic manner with didymo, concentrating nutrients (phosphorous is one). The discovery of this symbiosis-like situation helps illuminate why didymo can grow in low nutrient environments.
It's not as easy as adjusting P (or other nutrient levels). Perhaps the next "treatment" will involve competing these symbiotic bacteria with ones that do not 'feed" the didymo. But, this is dangerous too. Who knows what eliminating these microbes might do to the ecosystem

 

[whheff]

Good article. Thanks for sharing it.

 

[JeffK]

The didymo in the upper East Branch is odd. The last years it was horrible creating huge mats everywhere. This year I've been fishing around Corbett and haven't seen any. Hopefully it has naturally reduced.

 

[JeffK]

Some of the unresolved issues have a similarity to the invasive species issues with phragmites and sea lampreys in Lake Ontario and the Finger Lakes. Both are native, but both went crazy due to human caused changes. In the case of phragmites, the current thinking is that introduced European strains interbred with the native strains causing a super strain that takes over wetlands. In the case of the Finger Lakes sea lampreys it appears sedimentation of the tributary streams made much better breeding habitat. Why native species become "invasive" is a more interesting, but difficult problem.

 

[krayfish]

I also fish up near corbett and don't see much. I think it was in that big flat able Al's if I remember correctly. It comes and goes.