How to Read a Hatch Chart
|Fly Fishing the Great Smoky Mountains National Park
The hatch rating is provided to give anglers an idea as to the availability of an insect or what the trout are most likely feeding on. It is not a
rating of importance. An insect with a one * rating may be more important than anything else at a particular time of the year, month, day or
hour. A ***** rating simply means there usually are a lot of the insects available. This doesn't necessarily mean that the insect is available
any and everywhere on the stream. It is available only where the insect's preferred habitat exists on that stream. If the trout are feeding on an
insect with a * star rating and it is the most available insects at the time, it is very important. What is important is what is hatching at the time
you are there fishing.
On any given stream there may be hundreds of different species of aquatic insects that exist in some quantity. Some species may occur only
in certain isolated areas of the stream. We are listing what we believe are the most prevalent and important hatches that anglers should be
concerned with. Although the density of any hatch can vary drastically, the hatches are noted as ”dense, normal or sparse” in order that you
have a better idea of what to expect.
The species we list are usually not concentrated throughout the entire stream, only in the portions of the stream that offer the proper habitat.
For example, if a certain stonefly hatch is shown on a river that is thirty miles long, don’t expect to find them at the lower end of the river in
pools of slow moving water unsuitable for stoneflies. Also, you should be aware that hatches could progress upstream from day to day,
especially on those steams with steep declinations, so they may occur at different sections of water from day to day.
Remember that seasonal weather conditions can change the dates that hatches actually occur from the predicted time periods the charts
indicate. An unusually cold year may delay a hatch a week or two, in some cases, even longer. However, the sequence in which the different
specie hatch will generally occur in the same order.
Prior to fishing any given stream, you should make a list of the insects and other trout food shown on the hatch guides along with the
recommended flies that imitate them for the time period you intend to fish. Make some allowances for the indicated time period, just in case.
In other words, if a certain insect is shown to start hatching on March 1 and you are fishing February 26th, list it.
Do not forget that the charts show the predicted “hatch” dates. Normally, the nymph or larvae, and pupa stages of the insects are available
for trout to eat well in advance to those dates. In fact, in many cases, depending on the particular species, the insects are much more
important to the angler prior to the hatch than they are after the hatch occurs.
Copyright 2011 James Marsh