Deep Salmon Breakthrough

All of this begs questions nobody can yet answer. Like, what are they eating at that depth? We can’t trust stomach content, because kings may have been 400 feet higher in the water column mere minutes before being hooked downtown.

Dr. Jeff Schaeffer of the U.S.G.S. says alewives and other baitfish have declined severely in shallow-water habitat throughout Lake Huron and Lake Michigan. “Salmon could be going deep because that’s where the most prey exists,” he says. “The prey I suspected was the bloater chub, but we don’t find them any deeper than 350 feet. We don’t have much data from deeper than that. We know sculpins can persist down to 150 meters (492 feet), so they’re probably found in the deepest areas of the lake. On Lake Superior, during the course of deep exploration with a submarine, fish of various species were found at the deepest points of exploration, over 1,000 feet down.”

Sculpins, like gobies, have no swim bladders and cannot suspend off bottom, which could be the reason Chmura always finds deep, active salmon pinned to structure. And Chmura’s 10 a.m. schedule plugs nicely into Bergstedt’s data, which revealed that summer salmon were grouped tightest during the low-light periods of morning and evening, usually somewhere between depths of 45 and 90 feet. At daybreak every day, some of those fish went deep, but some moved even shallower. During the day, tagged salmon moved up and down like yo-yos, and were scattered widely from 50 to 500 feet at any given moment.

“I just changed from 500 feet of cable to 750 feet on my Big Jon downriggers,” Chmura says. “Some spools hold 2,000 feet. This year, I’m going down until I find their maximum depth range. I think kings are using the deepest water, depths of 900 feet and greater, in Lake Michigan. At any rate, adult salmon are biting near bottom as deep as I can troll. And I wouldn’t know where to troll without the split-screen zoom function on my sonar. Without it, you’re not going to see these fish. I’m using Si-Tex sonar right now, but I’m thinking of switching to Ray Marine. The Ray Marine E-Series includes a model that has GPS in 3D that shows you nooks and crannies at those depths. I set the zoom at 10 feet above bottom, making it far easier to locate fish when you’re talking about sounding through 500 feet of water column. Trying to locate and zero in on suspended fish at 500 feet is like targeting mosquitoes with a slingshot. Using a 24-pound downrigger ball near bottom, I caught kings as deep as 436 feet, which was my maximum operating range last year. This year, I’m goin’ way downtown, but staying on structure.

“My Si-Tex graph, with the zoom showing the bottom 10 feet, always shows activity, every month of the year. I thought they were whitefish and lake trout at first, but the majority of those fish are kings. How many times have you had people say their depthfinders suddenly lit up with fish? When I hear salmon fishermen say it, I believe those fish suddenly rose from the depths.”