Nymph Survey Through the Seasons

[Dave_W]

redietz wrote:
I'm not saying the data you have isn't valuable, just wondering what your thoughts are about biases?

At any rate, thanks for taking the time to do this.

This is worth noting and a good point: the methodology - kick seine in riffles - would likely select more for certain species. For this reason, many macro surveys include, in addition to the seine, manual examination of rocks and woody debris. For reasons of time I simply had to limit the locations and survey methods. Perhaps in the future, we can follow up on this survey with larger sample sizes/methods and more waterways(?).

Regarding caddis, the surveys did reveal a good number of them and in Concocheague caddis did outnumber mayflies by a small percentage during January and November. Some evidence of caddis cases did turn up in the siene but I did not count them in the bug totals unless an actual nymph was visible. These cases were mostly grannom "boxes."

 

[afishinado]

One thing often overlooked by anglers seining for bugs or turning over rocks to determine what to tie on their tippet, is how often will these creatures end up in the drift and be available for fish to actually feed on?

Many/if not most of these macros, especially the immature ones, will stay hidden from fish under rocks until they are ready to hatch.

A more useful utilization of the info gleaned would be the prediction of hatches in the future - ie, if you find a bunch of immature hendrickson nymphs in the winter, that's the place to be in April during the hatch.

In addition, as mentioned above, many macros are hidden in the substrate, in weeds or roots or wood or maybe found in deep water.

It's fun to check out the bugs in the stream, If you do it often enough, during different seasons and in different places on a stream, you can get a handle on what the macro population consists of in that stream. This will allow you to make a more informed decision on what fly to fish that day, and maybe more important where to be when the hatches occur.

......or just use the "Mo" method > fling out a pink worm and hope

 

[Maurice]

I don’t know why you gotta poke me in the eye to make your point. I am one of the biggest proponents of turning over rocks. And to your point, there is a thing called biological/behavioral drift that occurs at sunrise and sunset for about an hour where the “homeless” macros roam the currents looking for new places to habitate.

Some of those are aquatic worms of the pink variety...I hope anyway.

 

[Dave_W]

afishinado wrote:
......or just use the "Mo" method > fling out a pink worm and hope

I'll pile on and poke Maurice in his other eye....

Kidding aside however, aquatic worms were prevalent in this survey. If you go up a few posts (#35) to the November Letort photo, you can see some worms. The tiny red midge larva are obvious but also in that tray is a typical worm. The worms I found in my seine looked just like conventional earthworms in form and color, however they were very small, usually only about 1-2" in length and 1-2mm in diameter.

Also of note, although they were never numerous, worms were present in all seasons.

 

[troutbert]

Maurice wrote:

Some of those are aquatic worms of the pink variety...I hope anyway.

http://www.nwnature.net/macros/worms.html

 

[afishinado]

Maurice wrote:
I don’t know why you gotta poke me in the eye to make your point. I am one of the biggest proponents of turning over rocks. And to your point, there is a thing called biological/behavioral drift that occurs at sunrise and sunset for about an hour where the “homeless” macros roam the currents looking for new places to habitate.

Some of those are aquatic worms of the pink variety...I hope anyway.

Behaviorial drift is an interesting as well as complex thing. It depends on the types of insects, time of day, season, predators, O2 content, temperature......

My point is, checking out the bugs under the rocks is definitely a smart thing, but it really doesn't solve the puzzle, for the most part it just lays out some the pieces of the puzzle.

And yes aquatic worms are a piece of the puzzle....DaveW seined up a whole bunch in the Letort a few years ago as I recall. All fun.

 

[JackM]

Dave, I am curious about your seining technique. Do you have pictures of your net and how you use it?

As for Maurice's eye, I am reminded of the late great comedian Rodney Dangerfield: "My wife has all these marks all over her from people touching her with an eleven foot pole."

 

[Dave_W]

JackM wrote:
Dave, I am curious about your seining technique. Do you have pictures of your net and how you use it?

I use what is commonly referred to as a "kick seine." Mine is homemade using soft window screen material between a couple of poles about 4' in length. The net part itself is about 20"x24 inches. I believe in PA such a seine must not exceed 4' square in total net size(?).

The way you use this is you stand in shallow current and put the net downstream of your body so that the mesh is down on the stream bottom. While holding the handles, you then use your feet to shuffle ("kick") the rocks just upstream of the net. To be consistent in this survey, I made three side to side kicks and three forward and backward kicks followed by a 10 second count before lifting up the net.