Grannoms and treatment plants

[TimRobinsin]

I hit a creek a few weeks back that had crazy amounts of grannoms on top of the rocks below a treatment plant but above the treatment plant there was nothing to be found.

now maybe the treatment plant wasn't the only thing going on here but has anyone ever noticed this or seen this before?

 

[troutbert]

What stream was it?

To answer the question, no I've never seen that. It is common to find large numbers of Hydropsyche caddis below sewage plants and fish hatcheries.

To find large numbers of grannoms below a sewage plant is surprising, and interesting.

 

[dryflyguy]

And to see grannoms anywhere this time of year, is very surprising to me.
Are you sure they weren't stoneflies?

 

[JMP]

The treatment plants provide certain nutrients into the water that grannoms desire (I believe nitrates). When the treatment plant in Tyrone is required to remove these, we will see a dramatic decrease in the grannom population in the Little J.??

 

[TimRobinsin]

These were chimney caddis.

I posted about them on my website. I will put the link here because I can never get pictures to work on this site plus they are all on instagram so I have no idea how to get them from there to here.

www.keystoneflyguides.com

let me know what you guys think. I think the treatment plant played a big factor in this. These caddis were literally all over all of the underwater rocks, especially large submerged rocks approx the size of a soccer or basketball. Perhaps these rocks hold heat longer in the winter?

Anywho, it was a fun encounter.

 

[troutbert]

I went to your website.

OK, so we're talking about the Bellefonte sewage plant on Spring Creek.

And yes those are grannom caddis cases and larvae.

There are significant numbers of grannoms in Bald Eagle Creek, and in Spring Creek from the mouth up to Bellefonte.

(There are also some from Bellefonte on up at least as far as Rock Road, but only in small numbers.)

Grannoms have been in Spring Creek from the mouth up to Bellefonte since at least the late 1980s, when I first saw them there, so it's not a recent change.

I've seen loads of grannoms flying around and on the bridges at Lamb Street and High Street (just below the park in Bellefonte), which are locations well above the sewage plant.

I think the reason there are many grannoms below Bellefonte, but few above is the influx of a very large volume of cold, clean water from Logan Branch, and the Big Spring, at Bellefonte.

Grannoms certainly do not need sewage plant discharge. They are found in many places in large numbers with little or new influence from sewage discharge, and of course existed for thousands of years before sewage plants existed.

 

[Acristickid]

Isn't water reentering the waterways from the treatment plants generally warmer? Wonder if has any impact?

 

[troutbert]

acristickid wrote:
Isn't water reentering the waterways from the treatment plants generally warmer? Wonder if has any impact?

That's opening up a different topic, so it would be better in another thread, in the conservation forum.

But the answer is yes, in the summer, sewage plants can warm the water, and the effect can be significant.

 

[dryflyguy]

There are also sewage treatments plants dumping into spring creek upstream of Bellefonte. And if that was something that aided a grannom hatch, you should also see nice hatches of them on those stretches - which you don't.

 

[troutbert]

I checked some rocks in a few riffles above the kayak course, about 0.5-0.5 miles above the sewage discharge. There were lots of grannom cases on the rocks there. About a dozen or so on average on a rock the size that is easy to pick up with one hand.

When looking for grannoms, look in fast, tumbling, rocky riffles. They were plentiful there. Even in riffles with moderate flow speed, there were few. In slow water you'd probably find none at all.

I also found a March Brown nymph, which is cool to see in Spring Creek. They are not real abundant in Spring Creek, but there are some.

 

[TimRobinsin]

Thanks Dwight, that is very insightful.

I suspected that Bald Eagle may have had something to do with this as well.

It's interesting to think that a larger body of water can serve as a reserve or pathway for species to slowly migrate to other streams. the example would be if a tributary doesn't have a particular hatch but the larger body of water does the bugs can make there way up from the larger, potentially more diverse water and populate or in cases of pollution repopulate a stream after a bug kill.

Thanks for the info man. It was really crazy to see that many all over the tops of the rocks. It was really like when I wasn't catching fish I was hooking those damn caddis !

 

[troutbert]

The grannoms were in that part of Spring Creek when I first began fishing there regularly, in the late 1980s.

Whether they were always there, or whether they were wiped out at some point, then re-colonized, I don't know. I think either scenario is possible.

 

[albud1962]

I saw some grannoms at benner spring today. Not many but the fish sure liked them.

 

[nymphingmaniac]

grannom like algae. Treatment plants and hatcheries promote its growth. Both chemistry and warming the water