AiS Challenge Team Interim

Team Number: 093

School Name: Silver High School

Area of Science: Physics

Project Title: Physics of "Electrofishing"



Physics of Electrofishing

By Monte Topmiller and Davin Richardson

Phase I

-Problem Definition-

Electrofishing is the use of electricity generated by batteries, electric generators and other sources of electric power to kill, stupefy, disable or render unconscious fishery species. If it is done right, it is a fun and easy way for biologists to catch, study, and release the fish back to the water unharmed. When using the Type VII Backpack Electrofisher, an electrode is put into the water sending out pulses of electricity to shock fish. Once a fish has been shocked with the correct amount of electricity it will either float to the top and be caught with dip nets or it will flow down stream into a seine. If too much electricity is shot out, the fish that are wanted for studying will be electrocuted to death. When a fish has been shocked with too much electricity, muscle hemorrhage and spinal damage are caused by contractions on both sides of the fish. If too little electricity is used the fish will be unaffected and will swim off. Either way, the results of a shocking trip will be unreliable. This is why it is important to have the electorfisher set on the proper settings and have an experienced user. Even with an experienced user there is a lot of time wasted because the biologist have to start at a low level of electricity and gradually move to the right setting in order to not harm any fish. These settings still might not be the best that they can be and will destroy the reliability of studies. When a biologist does this, the lower amounts of electricity might not be able to shock the fish and instead will just scare them off and by the time the electrofisher is set on the proper settings there might not be any fish left. Most people would say that if this scares off fish, just start at a higher level of electricity. This is not a good way either because the shocked fish will not just be shocked they will be killed.

-Problem Solution-

Biologists are not electricians therefore a solution to this problem would be an easy to use program that could be used on a laptop that explains the basics of fish shocking electricity. A program that the user could input what they think the electorfisher should be set at and the computer would in return give information that would either support the decision or recommend another setting that would be better. The outputted information would be the shape of the pulse, the width, and the frequency. Other outputted information would be some basic information that would help in the final decision such as the high or low conductivity, big or little fish, temperature, etc. For high conductivity if might look something like this.

High Conductivity: Use low voltage and high currents. A program of this nature would not only save time but would also increase the reliability of studies by allowing biologists to only shock an area once and to be sure the right amount of electricity is used.

-Progress to Date-

The progress of this project to date has mostly been researching and finding information on: the affect electricity has on fish, the width and frequency of the pulses, and which pulses are the best considering different variables. Among these variables are conductivity of fish, conductivity of water, conductivity of lake or streambed, size of the fish, and the temperature of the water. The next step (Phase II) in this project will be writing a C++ program that calculates all this information and outputs an idea of what the electrofisher should be set at. After this is completed it will be time to go out into the field and test the program making sure it works as it is supposed to. (Phase III)

-Expected Results-

The expected results of this project are a user-friendly C++ program that is professionally written and a helpful hand. A program like the one described in the problem solution section of this report is what the planned finish project will be. A biologist that is new to fish shocking will be able to shock without harming any fish and will still be able to make reliable studies using this program.

Team Members

Team Mail

Peggy Larisch

Joy Garcia