While Iowa lawmakers have been discussing high-tech ways to track criminals in the state, a project that’s tracked one of the state’s natural resources has been going on for over two decades. Iowa Department of Natural Resources biologist, Jonathan Meerbeek, oversees the program that keeps a database on the walleye population in the Iowa Great Lakes.
Meerbeek says they use tags that are attached to the lower jaw of the fish. “It just has a unique code, usually a letter followed by two numbers and different colors. By using the color coding and different numbers we can uniquely individually mark fish and follow their growth in that fish’s history over time. And by looking at that, we can use some certain models that they use to evaluate abundance and other population dynamics of the walleye population,” Meerbeek says.
The D.N.R. does annual surveys of the fish in the spring and they get reports from people who catch the fish and read the tag. Some fish they see every year and that gives them individual growth information on them. Right now they have about 24,000 walleyes that sport tags from the D.N.R.
Meerbeek says the tags offer some fun information for anglers who are curious about their catch. “The can report that fish, that tag that they catch, if they harvest it or if they release the fish, they can call in and see the history of that fish,” Meerbeek explains. He says the more people that call in information on tagged fish, the more they know about the population.
The data they’ve collected show a strong population. “In more recent years we’ve seen some really good abundance estimates for walleyes in the lakes, where our brood stock is getting to a good number, where it doesn’t take us very long to get to our egg collection nowadays,” Meerbeek says. He says in the past it could take two to three weeks to get enough fish to collect the eggs for the hatchery, while now they can do that in two or three nights.
The Spirit Lake hatchery uses the eggs to produce more than 67-million walleye fry that are eventually stocked into lakes and streams all across the state.