Increased number of predatory walleye recorded at Lower Granite Dam | Idaho

LEWISTON – Walleye unfold all through the Columbia River Basin following an unauthorized introduction into Lake Roosevelt within the mid-Twentieth century. These fish remained downstream of Idaho’s salmon and rainbow trout rivers till not too long ago. Information collected on the Decrease Granite Dam grownup fish entice confirmed that walleye have been shifting by means of the fish ladder and have possible handed over this dam since a minimum of 2016 (2016=2; 2017=11; 2018= 49; 2019=20; 2020= 45; 2021=75).

The grownup fish entice is positioned midway up the fish ladder and permits biologists to entice and manipulate a few of the fish shifting up the ladder. Because the grownup entice solely collects a portion of the fish shifting up the ladder, the numbers symbolize a fraction of what has really occurred above the dam lately. Fish and Recreation estimates that 160 walleye in 2020 and 294 in 2021 handed by means of the Decrease Granite Dam, and the passage in 2022 guarantees to be the biggest but. Moreover, anglers are more and more encountering walleye within the anadromous waters of Idaho, together with a fish caught greater than 80 miles up the Salmon River close to Riggins.

Walleye are environment friendly and opportunistic predators that feed on migrating salmon and rainbow smolts. Juvenile salmonids in Idaho’s rivers and streams are already being affected by predation by native and non-native birds and fish, and as extra walleye proceed to maneuver and colonize upstream of Decrease Granite, predation charges will proceed to extend. Downstream researchers have estimated that walleye eat a median of about 2.5 smolts per day within the spring (McMichael and James 2017), and that non-native predators, together with walleye, might eat as much as 17% of some juvenile emigrant populations (Harnish et al. 2014). This mortality scale could scale back grownup returns.

Angling encounters with walleye will solely enhance as extra of those fish cross over Decrease Granite, so it could be time to hone your walleye identification abilities. yellow. Usually talking, the walleye has a darkish inexperienced again, which transitions to a golden aspect and a light-weight white stomach. Walleye is carefully associated to yellow perch, however lacks the darkish vertical bars you’ll see on the aspect of a perch. The walleye has a protracted, slender form with a tapering head, considerably much like the overall form of a northern pike. Nonetheless, these two species can simply be differentiated by remembering just a few key traits. Walleye has two distinct dorsal fins (the primary has spiny rays and the second has tender rays), whereas northern pike has just one soft-rayed dorsal fin. Additionally, walleye have sharp, apparent tooth, whereas pike don’t have any tooth (do not attempt to seize a walleye by the lip!). When you have questions on figuring out walleye and different species in Idaho, see pages 58-61 of the 2022-2024 IDFG Fishing Rules.

Within the anadromous waters of Idaho (Clearwater River, Salmon River, and Snake River under Hells Canyon), there aren’t any restrictions on the day by day bag, dimension, or possession restrict of walleye. The typical walleye now we have sampled from the Decrease Granite Scale over the previous few years has been practically 18 inches and just below two kilos, with the biggest fish reaching 23 inches and 4 and a half kilos. Fish and Recreation officers say that when you discover one on the finish of your line, you are inspired to maintain it and luxuriate in it as a meal.