The tags, which are embedded into the snouts of the young fish, include numbers identifying when and where the fish were stocked. The tags themselves are smaller than a fine sliver of pencil lead, yet when entered into a database maintained by U.S. Fish and Wildlife Service scientists, they provide a powerful narrative about the lives of these fish.

“We could not undertake this type of research without the support of an educated and dedicated group of anglers willing to save the fish heads and bring them in to our collection points,” says Eggold. “The results continue to provide incredible insights into the movement and reproduction of Chinook salmon while demonstrating the benefits of interstate cooperation. For example, anglers harvesting fish in Racine are catching fish stocked everywhere in Lake Michigan and in some cases, fish stocked in Lake Huron.”

While the natural reproduction data varies somewhat by year – in part due to inconsistencies in the number of fish heads collected – a six-year time series dating from 2006 to 2011 indicates natural reproduction levels well above 50 percent. The results represent good news for anglers, whose license purchases have provided the funding to support biological research, as fisheries managers will continue to fine-tune stocking strategies based on the latest scientific data.

Eggold says state agencies with jurisdiction surrounding Lake Michigan as well as the U.S. Fish and Wildlife Service would like to encourage anglers to continue providing fish heads so the research can progress through additional years. While the tiny coded wire tags placed in the snout of the fish may be difficult to see, anglers can tell whether their salmon or trout carries a tag because the adipose fin on the fish’s back, just in front of the tail, will be missing.

DNR appreciates the efforts of the more than 200 anglers who participated last year and the businesses that serve as collection points. These businesses have been given a supply of forms for anglers to fill out and bags to use for freezing the heads.
The forms ask anglers to include basic information such as the date of capture, capture location, fish species, length, weight and gender. Drop-off locations include:
• Algoma – Algoma Hardware, 513 4th St., 920-487-3374;
• Green Bay – Department of Natural Resources, 2984 Shawano Ave., (Hours – Monday-Friday 8:30 a.m. to 4 p.m.), 920-662-5100;
• Kenosha – Gander Mountain, 6802 118th Ave., 262-857-3757;
• Kewaunee – Accurate Marine and Storage, 203 Dodge St., 920-388-2326;
• Marinette – A&K Feed, Seed, & Bait, 1616 Shore Drive, 715-732-6100;
• Milwaukee – Gander Mountain, 6939 S. 27th St., Franklin, 414-761-1500;
• Milwaukee – DNR, UW-Milwaukee School of Freshwater Sciences, 600 E. Greenfield Ave., (Hours vary – Monday-Thursday – call ahead), 414-382-7929;
• Peshtigo – Peshtigo Shell Gas Station, 815 French St., 715-582-3681;
• Peshtigo – Department of Natural Resources, 101 N. Ogden Road, (Hours – Monday-Friday, 11 a.m. to 2 p.m.) , 715-582-5000;
• Port Washington – The Bait Box, 215 E. Washington St., 262-284-9355;
• Racine – Turk’s Bait, 2950 93rd St., Sturtevant, 262-886-3061;
• Racine – Department of Natural Resources, 9531 Rayne Road, Suite 4, Sturtevant, (Hours – Monday-Friday, 11 a.m. to 2 p.m.), 262-884-2300;
• Sheboygan – The Wharf, 733 Riverfront Drive, 920-458-4406;
• Sheboygan – Department of Natural Resources, 1155 Pilgrim Road, Plymouth, (Hours – Monday-Friday, 11 a.m. to 2 p.m.), 920-892-8756;
• Sturgeon Bay – Howie’s Tackle, 1309 Green Bay Road, 920-746-9916;
• Sturgeon Bay – Department of Natural Resources, 110 S. Neenah Ave., (Hours – Monday-Friday, 11 a.m. to 2 p.m.), 920-746-2860; and
• Two Rivers – Seagull Sports Marina, 1400 Lake St., 920-794-7533.
For more information, visit dnr.wi.gov and search for “adipose missing fin.”