Skip to main content
idfg-badge

Idaho Fish and Game

Another Dry Year for Fisheries

idfg-staff
A dry spring across southern Idaho may be signaling another tough year for fisheries. A detailed article on the impacts of drought on fish can be found in the current issue of Fish and Game's web magazine at www2.state.id.us/fishgame in Incredible Idaho. The following is an abbreviated version of Vicky Osborn's article: Drought. This one word captures the slow, painful experience of a landscape shriveling up from lack of water. Not much is spared and not much can be done about it. Agriculture interests learned to stave off drought by building reservoirs to trap snow melt and spring rains for when water was needed another day. But even reservoirs are vulnerable to drought. In 2001, five reservoirs were completely drained to meet irrigation demands. Other reservoirs were severely drawn down.There simply wasn't enough water to go around and many farmers and ranchers chose not to fight the drought. Instead of using their water to irrigate crops, they leased their share of the water to Idaho Power for generating electricity. When drought overwhelms Idaho, people aren't the only ones who lose. Many reservoirs support local fisheries, especially in southern Idaho. Last summer, many popular fisheries were lost when reservoirs dried up, fisheries suffered when stream flows fell dangerously low, and wild native fish populations dropped as well. Idaho Fish and Game's attempts to maintain the state's valuable fisheries set in motion a complex juggling act. Declining waters creates a moving target for fishery managers. All summer long they juggle a series of questions. Will a reservoir hold water through the season? If so, will there be enough for fish to survive the winter? If not, when will it go dry? Will the spring be wet enough to stock catchable trout for a May and June fishery? What happens to the fingerlings that were destined for a faltering reservoir? What body of water can take what are now surplus hatchery fish? Is a fishery ultimately going to be lost and should it be salvaged? Salvage Fishing Fishery managers prefer to see anglers salvage fish through fishing, as opposed to implementing costly salvage operations. Largescale salvaging operations are expensive and often the number of fish saved doesn't justify the cost of time and money. However, when the right conditions exist, Fish and Game collects fish from failing bodies of water and transports them to other waters. For example, last summer Indian Creek Reservoir was drying up. Fish crews collected bluegills and bass and moved them to several urban ponds in Boise where anglers could still fish for them. Silver Linings and Surplus Hatchery Fish While fish populations decline and disappear in some waters during a drought, fisheries in other waters may get a boost. Such was the case of C.J. Strike Reservoir on the mainstem of the Snake River. In typical water years, C.J. Strike provides a modest trout fishery. In 2001, however, lower flows in the Snake River meant water moved more slowly through the reservoir. This allowed more nutrients in the reservoir to be converted into more food for fish. At the same time, some fish initially scheduled for other, drought-stricken, reservoirs wound up being stocked in C.J. Strike. Trout Fisheries The department actively stocks both catchable and fingerling trout in many bodies of water. Catchable trout are about 10-12 inches long and put in the reservoirs to provide a readymade fishery for anglers. Most of the trout stocked are fingerlings and take about a year to grow before they provide good fishing opportunities. Fish managers say it only takes 12-18 months to kickstart trout fisheries in reservoirs that have gone dry. Unfortunately, another summer of drought is predicted across southern Idaho, and restocking reservoirs with fingerlings will have to wait another year. Catchable trout were stocked in reservoirs that had enough water for a spring fishery. Idaho's native trout evolved with lean water years and are fairly resilient. Drought may set their numbers back, but they will rebound naturally as long as water flows return the following year and habitat is good. Natural production is the backbone to keeping healthy populations in stream fisheries. Unless a stream was completely dewatered, which would kill both juvenile and adult fish, most anglers probably won't notice the effects of a one-year drought. Warm Water Fisheries Warm water fisheries are rebuilt through natural production. When these fisheries are lost Idaho Fish and Game starts from scratch, restocking waters with adult crappie, bluegill and bass. The fish can be caught, but the goal is for them to spawn and create the next generation of fish. It takes two to three years for crappie and bluegill to become a mature fishery again, and four to six years for bass. Outlook Fish managers were anticipating drought conditions in southern Idaho in 2002. Some reservoirs didn't have enough water to stock fish, while others only had enough water for a spring fishery. Once again, reservoirs on the mainstem of the Snake River, like C.J. Strike, are offering excellent fishing. There's likely to be good stream fishing in the spring in low water areas, as well. Anglers in most parts of the state should have a typical year. But the best advice for anglers in southern Idaho is go fishing early and often.