Matching the hatch at Bennett Spring
While fishing at Bennett Spring State Park, I tested the insect population in the outflow stream below the hatchery runways. I used an insect seine that I got from Allen Gardner’s Insect Course. I wrap this seine over the outside rim of my fish net, hold it in the water with the rim on the bottom of the creek, then I kick up the creek bed with my foot upstream of the seine. This will tell me what critters are crawling around and available for the fish to eat. I found sowbugs. Nothing else. They were dark grey and most were about the size of 16 hook. There were fewer size 18 and one size 20. I tied on a light grey sowbug fly and had good success with it until I lost it. I tied on another sowbug that was darker and should have been the first fly. I thought it was brown but upon closer examination, it was the Goldilocks shade of grey. I did well. I also tied on a bead head Prince Nymph above it. To my surprise, the fish took it about half the time. I usually tie my dropper tippet onto the bend of the upper hook with less than happy results as they almost always take the bottom fly. By tying both flies into the upper hook eye, I had better hook ups on the upper fly. Note that I was directly below the lowest raceway outflow.
I wonder why I didn’t find any nymphy looking things in my seine. Two guesses. I didn’t exactly test the whole water column, just the creek bottom. I tested the slower water where I could stand safely without fighting so much current. Maybe just a couple of feet to my left where the current is stronger and the rock sizes are bigger, there are nymphy looking things deeper down between the rocks. I would also be interesting to check further downstream to see how the populations change. I did this once before down by the Gut Hole and found some scuds.
Yes, I know you cannot net trout. When I test the water for insect populations, I place my rod in a safe place on the bank. I think that if I have to explain myself to a conservation agent or park ranger, it will help to show him/her the bugs in my seine. They would surely think me to be completely stupid to be kicking up the stream bed while trying to net a fish. I think they would also enjoy the knowledge gained.
Yes, I know that sowbugs are not insects. They are aquatic crustaceans in the Isopod order. The fish don’t care.