Lasers used in fish research
The Michigan Department of Natural Resources is working closely with biology department faculty member Kevin Pangle and some of his ecology students to conduct research with otoliths in different fish species.
One of the more prevalent fish being researched is the steelhead fish, being studied in 40 different streams in the Lake Michigan Basin.
“This gives me more of a real world application for research,” said graduate student Nicole Watson, who is using the steelhead research for her thesis. “I can actually see how the fish species will be targeted better so it’s really good (working with the Michigan DNR).”
The graduate student said she is typically in the lab every day extracting and preparing otoliths—commonly known as “fish earbones” from steelhead fish. After the otoliths are removed from the fish, dried, embedded in epoxy, cured overnight, sectioned, polished, prepared and cleaned, they are finally ready for laser ablation, or removing materials from the specimen with a laser.
Watson said she is fortunate enough to have student volunteers to assist her with each step of the process.
The laser ablation process takes place in the Central Michigan Research Corporation's CART facility, in Mount Pleasant's Smart Zone. Otoliths are shot through their core with a laser to retrieve information about the origins of the fish and the chemical makeup of the streams it swam in.
“It’s like a diary with the fishes’ whole life history and it’s so subtle and minute, but we’re at the point in science that we can do all of this cutting-edge chemistry and figure it out,” Pangle said.
Pangle said the steelhead is a relevant fish to study in terms of research for the Michigan DNR because its importance in the recreational fishing industry.
“My goal is to protect our fish and their habitat,” Watson said. “I know that this work will benefit steelhead in the Great Lakes region, for both the management of the steelhead and their natal habitats.”
The research project has a projected duration of three years and is going into its second year. Watson helps students get into the lab to gain hands on experience as well.
Blanchard senior Frankie Baker is performing the same kind of research as the steelhead project with the alligator gar fish—a large predatory fish from Texas rivers. This work is almost entirely lab-based because the otoliths from the fish are shipped from Texas before they are able to be worked with in the lab and with the laser ablation.
“Getting to help future scientists understand and manage fish populations is very rewarding and I am extremely grateful for the opportunity I've been given," said Baker. "This project has been an amazing opportunity for starting my career in aquatic biology."
Putting in about 20 hours of labwork a week, Baker mounts, sections, polishes and ablates the otoliths of the alligator gar.
