The land locked king salmon fishery in Lake Oroville has been a tough one to figure out. They are a cold water fish that stays down deep for most of the season. Shore based anglers rarely can reach them and boat fishermen have a tough time finding the correct combination of depth, speed and lure.
The story of the cold water fishery in Lake Oroville goes back to the completion of the dam in the 1960s. The DF&W wants to have both a warm water fishery in the foothill reservoirs, bass, panfish and catfish as well as a cold water fishery, trout and/or salmon.
Originally there were rainbow trout planted in Lake Oroville similar to Shasta and other major reservoirs in the state. Then a problem arose. There is some pathogen that is natural to the Feather River above the lake that affects rainbow trout. The concern is that large populations of rainbows in the lake might become infected with the disease and contaminate the steelhead hatchery below the dam. The way to manage for this condition is keep the rainbow trout population to a minimum.
The quest then became to find a cold water fish that was immune to the condition to meet the cold water fishery goal for the lake. One candidate was the king salmon that were raised in the hatchery below the dam. I remember the 1990s and the reports from Oroville mentioning fishing deep with minnows near the face of the dam to catch king salmon.
After the turn of the century the cold water component of the lake was shifted to silver salmon. Eggs were brought in from Washington state and raised in the Feather River Hatchery then planted in the fall. The silver salmon fishery was very well received by anglers. Silvers are aggressive fish that readily hit almost anything that moves. With up to 400,000 per year planted in the lake the catching was excellent. Even the bass anglers were catching lots of silvers. The problem was that silvers were escaping into the river system below.
Current policy of the DF&W is prejudiced against non native fish and the decision was made to halt the silver plants and go back to the native king salmon. The silver salmon had increased the popularity of trolling at Oroville and with the change over there was a renewed interest in the king salmon and how to catch them.
Another component to this story is the bait fish in Lake Oroville. Originally shad were introduced as the forage fish. By the 1980s pond smelt were introduced into Lake Almanor up stream and they migrated down the Feather into Oroville.. Pond smelt have the trait of displacing other plankton feeding fish including both kokanee and shad. By the late 1990s pond smelt were the dominant bait fish. They have proliferated and schools of them have been seen as large as a garage.
After the reintroduction of king salmon the anglers began the process of trying to figure out this puzzle. A lot of the experimentation centered on the tactics that were effective on king salmon in Lake Shasta, “rolling frozen shad”, Speede Shiner spoons, Apex lures and anchovies. Yes, these caught fish but the bite was tough.
In mid July I received a call from Ed Fisk (www.fishtalesguideservice.net). He had been trolling on Oroville with a variety of lures. When cleaning the salmon he noticed in the stomach contents were small pond smelt, an inch to an inch and a half. Ed has a collection of trolling flies in his gear and he came up with a Marabou Minnow in the pond smelt color (http://www.trollingflies.com/marabou-minnow-series/ ). On his next outing the small fly put the fish in the boat. He only had one that size. He fished longer flies and hootchies in similar shades of white and everything was rigged behind a dodger. The longer lures did not produce. The variable was length.
Micro Tube Fly white (available 2017).
He asked if I could tie some micro tube flies in white with a hint of sparkle to reflect some light. Of course I could but I would need an invite to the test. We settled on a Friday and we were on the lake at dawn. The previous trip Ed had hit a school of fish a hundred yards from the spillway launch ramp and almost finished his limits right there. This day we picked up only one fish in the first hour and some doubt could be sensed on the boat by mid morning.
Another factor working against an early bite was the full moon on Wednesday. Typically on a full moon the best fishing is at midnight and again at midday. By late morning we began to hook up salmon. We were changing depths and locations. We never got into a red-hot bite but we consistently landed salmon and an occasional spotted bass. By mid afternoon we had a dozen salmon in the 14 to 15 inch range. Our first fish was hooked at 65 feet and by the end of the trip we were hooking them at 85 feet down.
We were trolling with four rods. Three of them were rigged with short white flies and one was set up with a two inch Apex spoon as a control. The Apex caught one or two and the balance were all on the Marabou Minnows and micro tube flies.
I think of fishing as a puzzle. There are numerous variables that range from moon phase, water temperature, depth, food type and location, lure color, boat speed and the list goes on. Success at fishing in large part is working through a process of elimination to find a combination that works at that time and place.
It is not possible to make a blanket conclusion about catching king salmon in Lake Oroville. The variables are constantly changing. I can say that the primary food of the salmon is the pond smelt. The smelt spawn in the late winter and mature adults can be as long as 3 inches the following year. Mid summer this year the salmon are feeding on smelt schools made up of 1” to 1.5” minnows and the salmon are selective on length.
My conclusion: Yes, contrary to some claims, size does matter!
This article first published in "The Union" newspaper Grass Valley CA. August 12, 2016.
Author: Denis Peirce