Spring creeks can be found all over the world and occur when groundwater bubbles up from below the Earth’s surface. But we’re pretty sure you already know that and are aware of how much trout love them. As the water comes up through the ground, it carries with it tons of nutrients and, usually, a perfect PH level and temperature for trout and their prey. These 2 factors allow for tons of vegetation and insect growth and essentially become a cafeteria for wise, old trout. For many anglers, these creeks are a daunting challenge filled with crystal clear waters, hyper-wary trout, and meandering confused currents. But with the right arsenal of flies and tactics, any angler can have success in these big trout factories. Personally, I believe the most important piece of that arsenal is a box full of Cress Bug patterns.
What Are Cress Bugs (Asellus aquaticus)
Cress Bugs (as they are commonly known to most anglers) are small macroinvertebrates (read: bugs) that make their homes in aquatic plants that call many creeks and streams home, but their favorite habitat of all is a cold spring creek filled with watercress. They don’t swim very well and spend most of their time in vegetation, but if they slip up and get caught up in the current, they make an easy snack for any hungry trout.
Cress Bug Fly Pattern Choice
As with just about any fly pattern in existence, there are infinitely different variations of this pattern, with tyers modifying color, size, shape, weighted vs. unweighted etc… to match the look of their local cress bug populations. I typically keep a few color variations of the fly above in my box, the most effective for my region’s (Southern PA) spring creeks are Olive, Rainbow, Brown, and Tan. I have found the best way to find out what your local cress bugs look like is to go to the creek, rip up a chunk of cress and see what color and size bugs fall out, or simply call a fly shop close to the creek and start asking questions.
How to Fish Them
You can fish cress bugs just like any other wet fly or nymph but when you are fishing in gin-clear spring creeks, a few special tactics are definitely worth trying out to fool your targets. Most typical spring creeks are slower moving creeks and this can pose a few challenges to anyone, first being that a slow current makes it easier for trout to sense you as you approach, so pay extra attention to how you are moving and be as stealthy as possible. Another challenge is the clarity of the water, this means that you will need to use lighter tippet (I almost always use 6x) and avoid loud strike indicators. My best method for fishing cress bugs is using a Dry-Dropper rig, this allows my presentation to be very soft, and I am still able to use my dry fly as an indicator of sorts. If you’re heart-set on using an indicator, I would recommend checking out this post to find the right one for your situation.
Now you’re ready to make your presentation to the fish. There are a few key places in the creek that you need to make sure you fish with your cress bugs. The edges of weed beds in the current are a prime spot for trout to hold while waiting for errant cress bugs to get knocked loose from their leafy abode. Run your flies along the edges and watch for the telltale flash of a trout munching a fly. Another tactic for fishing weed beds is to cast your flies over the top of the weed bed and drag them slowly across so they fall over the edge into the current, this will simulate a cress bug getting washed off the top of the weeds. This tactic has fooled a few wary trout that had previously refused other presentation styles. But most important is to fish them in all parts of the creek and to work all the water available to you.
Cress bugs will work in almost any part of a spring creek so be sure to work all the water available to you and keep your head on a swivel looking for trout. These creeks are a great way to hone your fish spotting techniques as the clear water will make it a breeze with polarized sunglasses. So stay stealthy out there my friends and give spring creeks and cress bigs a try this year, you won’t be disappointed.
Dan Zazworsky’s passion is sharing his love of fly fishing with anyone that will listen, read or watch. You can find him exploring new waters every day while chasing any fish that will eat a fly!