Fisheries technician Maddy Watt walked briskly toward the Boise River from a hatchery truck with a net full of about 25 wiggling rainbow trout.
She flipped the net and the fish were splashing, rolling and diving into the depths of the river.
Watt dumped several more netfuls of trout in a riffle near Barber Park on a mild February day. It was the first trout stocking this year for the river and nearby ponds, and a sure start of the fishing season.
Fishing doesn’t always mean catching, but with Idaho Fish and Game hatchery trucks rolling around the state stocking millions of trout in hundreds of lakes and streams, anglers’ chances go up pretty fast.
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That was easy to see a few days later when parents and kids were hooking rainbows with worms and PowerBait.
A lot of low-elevation waters in Southwest Idaho are stocked constantly from February to December, and that keeps anglers showing up on popular waters like the Boise River and Treasure Valley ponds even when it’s cold enough to freeze fingers.
Hundreds of thousands of pan-size rainbow trout are expected to be stocked in waters this year from McCall to Treasure Valley and beyond toward Stanley as the fish-stocking gets into high gear. Statewide, F&G plans to stock about 1.6 million catchable (10- to 12-inch ) rainbow trout in 2016.
“We choose stocking sites where anglers have access,” said Bob Becker, manager of the Fish and Game’s Nampa Hatchery. “We make sure the resource is available for the public.”
Becker’s philosophy echoes the policy of Fish and Game’s rainbow trout hatchery program. It exists for one sole purpose and that’s putting fish in Idaho waters for anglers to catch and keep.
So, let’s rig a line and get out there.
Here are some examples of how the crew at the Nampa Hatchery stocks the southwest region of the state:
Boise River: The urban river gets more fish annually than any single water in the region that is not a large lake or reservoir. The river from Barber Park to Star gets 30,240 (10-inch) rainbows and is stocked every month except January. The only time stocking can be curtailed is during high flows possibly from late April to early June. But that depends on the amount of snowpack and resulting runoff. In the height of the summer when flows are moderate, the river gets about 4,000 fish a month.
Treasure Valley community ponds: More than 110,000 trout are stocked in family fishing ponds across the valley in an area from Marsing to Kuna, through Boise and up to Horseshoe Bend and out to Weiser. The ponds are popular with families and are stocked almost all year, except when they are frozen. Stocking is limited in the summer months at some valley ponds because of hot weather and high water temperatures, which are lethal for rainbow trout.
Large lakes and reservoirs: About 140,000 (12-inch) trout are spread out across waters from McCall to Treasure Valley and some areas of Stanley Basin. These are waters such as Lake Cascade, Lucky Peak Reservoir, Horsethief Reservoir, Stanley Lake and Sagehen Reservoir. Most of the stocking is done May to early July.
Mountain stocking: Fish and Game stocks about 53,000 (10-inch) rainbows spread out in smaller loads to small lakes such as Bull Trout, Perkins and Josephus, as well as flowing waters like Silver Creek (near Crouch), the Middle Fork of the Boise River and Crooked River. The areas are stocked when high flows subside and access through snow is no longer a problem. Stocking is usually late May through Labor Day. These stockings are done for the summer camping crowd. Fish and Game targets popular camping waters just ahead of holiday weekends (Memorial Day, July 4, Labor Day). Fish stocking is also spread out throughout the month.
Fingerlings: The Nampa Hatchery stocks about 10,000 rainbow fingerlings at Deadwood Reservoir and 10,000 at Horsethief Reservoir. Fingerlings are finger-length fish that are allowed to grow up in the reservoir instead of the hatchery.
Other fish: Non-rainbow fingerlings raised at the hatchery include 20,000 landlocked fall chinook salmon for Deadwood, Anderson Ranch and Lucky Peak reservoirs. The idea is to introduce predator fish to control the kokanee salmon population and drive up the size of the kokanee. If kokanee become too abundant, they don’t have enough food in a reservoir and don’t grow to a larger length. About 10,000 brown trout fingerlings are stocked in Horsethief Reservoir, east of Cascade, and 43,000 Lahontan cutthroat fingerlings in the Riddle Lakes in Owyhee if there is enough snowpack in the Owyhee Mountains to supply enough runoff to fill the high-desert lakes.
Catch and eat hatchery trout. That’s why they are stocked. Releasing them doesn’t necessarily mean anglers are helping create a larger population of trout in a river or lake. Hatchery trout are sterile and will not spawn and reproduce. Releasing them could mean catching them another day, but it also can mean a wasted fish. If a hatchery trout is not released properly, it could struggle to live after experiencing the stress of being caught and released.
The taste of trout. The folks at Idaho Fish and Game say the taste is good because hatchery trout are raised on fish pellets made with fish meal. They don’t usually get complaints from anglers. In some cases, the fish meal used by Fish and Game comes from the same sources of food used at commercial hatcheries supplying restaurants. So, is the taste of a trout caught in the Boise River the same as that in a gourmet restaurant in New York City? You decide. By the way, Fish and Game says catchable-size hatchery trout retain a good flavor because they’re usually caught fast. They don’t have a chance to take on a different flavor. Some trout that remain in ponds or reservoirs for longer periods may get an off-flavor, especially as the water warms and more weeds and algae bloom in late summer.
Red-meated fish: Trout with red flesh aren’t necessarily wild fish. Fingerlings that are stocked and allowed to grow to adult size in a lake or reservoir may have flesh the same color as the pigments in the aquatic organisms that they feed upon.
How do you tell a hatchery fish? Hatchery-raised fish typically have some level of wear on the dorsal fin (the “shark” fin in the middle of the back). If you catch a rainbow in a water that is stocked and it has some fin wear, it’s probably a hatchery fish. This is a result of living in close quarters in the hatchery’s raceways and rubbing against other fish and rearing structures.
Ten-inch vs. 12-inch fish: Based on extensive catch-rate studies, Fish and Game shifted almost all large lakes (50 or more acres in size) to the stocking of 12-inch rather than 10-inch fish. This is a result of a study by Fish and Game. Fisheries researchers tagged thousands of fish over a four-year period, and tracked the tags with the help from anglers. The results showed that 12-inch rainbow trout are more likely to be caught than 10-inch trout. This has allowed F&G researchers to reorganize the hatchery rainbow trout program in a way that puts larger trout in the creels of Idaho anglers without increasing the cost of the hatchery program. The science and math showed that for every limit of six rainbow trout anglers catch, Fish and Game must stock roughly 18 (10-inch) trout. When 12-inch trout are stocked in the same waters, only 11 fish are needed for each six-fish limit, on average. The 12-inch fish are called magnums. F&G hatcheries have converted approximately half of the statewide catchable production from 10-inch fish to 12-inchers.
How long before hatchery trout bite after being stocked? It’s a common question, but Fish and Game admits that this is tough to answer. Sometimes it can be minutes, sometimes at least a day or so. Loading and hauling fish causes stress. One of the first things hatchery personnel notice if fish are stressed or potentially sick at a hatchery is their lack of appetite. Stressed fish will stop eating. It is common practice to leave fish off of feed for a minimum of three days prior to hauling, often longer, to help this issue and ease hauling stress. They might not bite right out of the truck, but it usually doesn’t take long. Fish usually start biting within a day or so after being stocked.
Zimo Note: I’ve caught trout within minutes of being stocked on a few occasions. Then on other occasions, newly released trout didn’t bite until a day or so later.
How often do you stock a fishing hole? The best way to find out is to check out Idaho Fish and Game’s website showing stocking schedules: fishandgame.idaho. gov/public/fish/stocking.