The Stream Doctor

August 18th, 2003


Q. From Tie 1 On: I am interested in studying aquatic insect ecology "up close and personal." To accomplish this, I'm contemplating an aquarium project. Most freshwater aquaria references don't address trout environments. Any tips, experience or specific references I could turn to? Thanks.

A. A noble project, but I hope you have plenty of money, resources, and facilities to undertake such a project. I say this because it is very difficult to culture most aquatic insects under aquarium conditions. This is a generality, because I don't know which specific insects you are talking about (stream insects, lake insects). Environmental characteristics such as physical (temperature, flow-rate, substratum type, light), chemical (dissolved oxygen, pH, nutrients), and nutritional (seston, algae, invertebrates, organic matter) requirements differ considerably from species to species and all have to be maintained properly if you expect to raise a particular species through its life cycle. For instance, if you are interested in studying a grazing insect, then you will have to furnish the proper substratum for it to live on, sufficient light to insure that its algal food base will grow on the substratum, the correct types and amounts of nutrients to be sure the algae will grow, and the temperature for all of this to work. The easiest way to solve much of this is to have a flow-through system using a natural stream for a water source. That usually provides everything except the substratum to your system.

If you are interested in stream insects, there have been a wide variety of systems used by scientists studying various aspects of insect ecology. These range from simple laboratory streams (a 6" plastic irrigation pipe cut in half lengthwise, filled with gravel and rocks with water running in one end and out the other) to elaborate experimental stream set-ups involving hatchery troughs (or something similar) with paddle wheels to maintain flow. We are currently using some wooden troughs approximately 50 meters long that can be adjusted for gradient in our research. Or people have used circular trough set-ups where the water is circulated either by air or a directed current to produce unidirectional flow. The point I'm trying to make is that there have been literally hundreds of different designs for studying aquatic insect ecology in the laboratory, but most have been designed with a specific purpose in mind depending on the goals of the research. I have used experimental troughs, flow-through glass chambers, plexiglass chambers, circular systems, linear systems, and others.

I'm not trying to discourage you, but to make sure you are aware of what you are undertaking. Rather than go on and on about the complexities involved, maybe it would be better if you let me know (via FAOL or directly to more about what species you are interested in, what environments, what resources you have, and something of your background (teacher?) so that I can have a better feel of what is involved.
~ C. E. (Bert) Cushing, aka Streamdoctor
105 W. Cherokee Dr.
Estes Park, CO 80517
Phone: 970-577-1584



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