Originally Posted by Hardyreels
I can relate to that, however I would caution against harvesting the largest males from the fishery. Those fish are indeed your hope for the future of fishing there. I also would keep a tight lip regarding any positive results to any other fishermen as far as where you fish exactly.
The first thing to do is to not fish, spend some time observing the pond. You haven't mentioned whether this is a beaver pond or some man made one. If there is an inflow you will want to pay close attention to that area. Through observation you will learn where the larger fish reside and feed. The smaller fish will occupy those ares allowed them by the absence of large fish.
Once determining where the fish are at you must now consider presentation. If the pond gets sufficient fishing pressure the large fish that remain are not there because they are stupid. They will be wary. Although windy days are not the best for casting fly lines they along with rainy days create enough surface disturbance to help to hide the landing of a fly line. If you wish to fish surface flies I would not go larger than a #18 Blue Quill and otherwise would use Lew Oatman's Brook Trout Minnow tied to his recipe.
The rest is up to you as far as your ability to make presentations when and where you need to. The point of study and observation can not be stressed enough. All to often a person begins fishing while having no prior knowledge as to where the fish are at. This often results in poor yield in catch. I do not cast until I am pretty sure I'm going to catch something. This would perhaps be a good experiment for you to adapt as regular practice.
A little insight to this pond:
It's natural, roughly rectangular shaped, about 2000 ft long by 750 at the widest. There's no beaver dam at the brook running out, but there's an active lodge about 100 ft from the brook running in.
That brook running in is slow moving and basically being fed by a marsh. It has a muddy bottom, 6'-8' wide and 4'-6' deep and I can usually hook 1 or 2 12" + trout in that brook on a spinner. The area, let's say 40' radius, where the brook runs in, has a few lily pads and grasses and is populated mostly (from what I can tell) by small trout up to 7". (NOTE: This is an area I like to fish with the fly rod because it's a comfortable place to learn with mostly scrub brush, so minimal taller growth to interfere with the back-cast.) It's just outside of that where the vegitation is more dense the bigger ones hang out, with a "reported" presence of numerous German Browns (personally, I've never hooked one here). A little point of land just below the beaver lodge gives access to the outer range of the vegitation line with spinning gear, and that's mostly where I hook the bigger ones. However, dense spruce and pine grow right to the edge, and the pond depth and bottom type prevent any access, even with chest waders, and hence for someone with my "fly" casting skills (or lack thereof
Now my thoughts have been that if I can catch decent trout in the brook, and know they're on the edge of and outside the vegitation line, they have to be travelling back and forth around the area outside of the brook. While I realize this is probably faulty logic, I haven't accepted yes it's totally wrong.
As for the diet of the trout, I've cut open the gut of several, and regardless of size, it looks to be the same with various small dark flies and some grubs.
I have had some success with the following popular local patterns for the smaller ones:
So, to end the rambling, the diet of all sizes of fish seems to be the same, hence the reasoning for the original question in this thread, the size of the fly.
From what I've taken from the responses in this thread, a #20 can just as easily take a big trout as a #12, so back to the drawing board and some more studying.