It’s not the biggest walleye to come from Lake Sakakawea, but it’s definitely the oldest.
The oldest ever documented, at least.
A 25.2-inch walleye sampled last July during an annual fisheries assessment on Lake Sakakawea was 27 years old, topping the reservoir’s previous oldest walleye, a 24-year-old fish collected the previous year, the North Dakota Game and Fish Department reported on its Facebook page.
Department fisheries biologist Russ Kinzler aged the fish by counting the growth rings on the walleye’s otolith, an ear bone, a process similar to how foresters age trees by counting the growth rings in the wood.
Kinzler said he’d heard of similar-age walleyes taken on the Missouri River System in Montana but none older, the Facebook post noted.
The Facebook post also indicated walleye abundance in Sakakawea is at its highest level since Garrison Dam was closed in 1953, and there’s a high abundance of fish in all ages and sizes.
“We have had numerous strong year-classes since 2010, and they have driven the population abundance upward pretty dramatically,” the post noted. “The presence of very old fish in a system does tell us one thing — that overall mortality (including natural and angling) is very low in Sakakawea. On Lake Sakakawea, we do have some very old fish as part of the population as well as many younger year-classes.”