Aquatic Insect Sampling

Aquatic Insect Sampling

Aquatic insect sampling is done to accumulate the information for stream monitoring.

The videos below were taken during a Sampling Class done by Enviornmental Quality Institute (EQI) at Haywood Community College*.

The above video is from a class on Stream Sampling conducted at Haywood Community College by EBI.  What is going on is a net is positioned below (about the same length below as is the size of the net) a partner who is kicking up the substrate to dislodge the developing insects below the surface of the bottom.  The Stream Monitoring Information Exchange (SMIE) recommended technique: One person holding the net and the other kicking up the bottom for a full one (long) minute.  The net is taken to the stream side and laid flat (preferably on a folding/portable table) There it is inspected by the same two persons.

The above video is  a clip illustrating the technique for getting the specimens segregated for identification.  First of all the net used for capturing them is placed down on the flat table surface.  Using the same two individuals who brought the net from the stream, the specimens are picked out of the net with tweezers and put into containers of water.  A prescribed formula  for this step of the sampling is two people spend 20 minutes picking the specimens from the net.  The specimens are picked out of the net and put into containers of water.  This can be done in one of two ways: 1.  Put all of the specimens into a shallow but larger container, then select certain types and put into segregated  containers of water…in this case the ice cube trays.  2.  Put the specimens directly into the ice cube trays segregating the different types as you go.

I heartily recommend this for anyone who is committed to fly fishing for trout.  It is many lessons on one trip.  I have done this before and never fail to learn a little more each time.

PS:  Is that Stonefly big enough for you.  Thought I was in Montana for a moment!

The other means of sampling a stream is by Visual sampling by turning over rocks, sticks, and inspecting; and inspecting the roots of trees etc that are visible along the bank.  Also inspect Leaf Packs where the insects are thriving between the leaves.  There are different population of insects in different locations on the stream, e.g.: riffles, runs, pools.

*I would highly recommend this one day class to anyone who has the slightest interest in our streams and the life under the surface, to attend a class and volunteer to sample our (or your) local streams.  It is a great contribution to the health of our streams and you will learn and have a great time getting close to what you love. Click on the EQI link for more information.