Pyramid Lake, located entirely within the Pyramid Lake Paiute Indian Reservation, is the terminal water body of the Truckee River system originating approximately 120 river miles upstream at Lake Tahoe. The Lahontan cutthroat trout (Oncorhynchus clarkii henshawi) is a member of the Salmonidae (trout and salmon) family and is native to the Lahontan Basin. It is the main sport fish in Pyramid Lake attracting anglers globally.
The Lahontan cutthroat is the largest of the cutthroat species. Cutthroats are an opportunistic feeder, with the juvenile diet consisting mainly of invertebrates while the diet larger individuals composed principally of fish. As far as my angling success goes, the Pyramid Lake Lahontan cutthroat population activity level is at a maximum from December through March although June can be spectacular!
The motives that stimulate folks to fish for the Lahontan cutthroat are diverse. Some wish only to get outdoors to relax. Many are motivated by the competitive urge. Others find in angling a means to explore and appreciate the splendor and mystery of Nature. I fish to catch fish and almost always succeed.
I fished Pyramid Lake at the end of April through early May. Once again strong winds limited the number of days I was able to fish. More changes were in store from my previous trips this winter and spring. Water temperature is on the rise. I opted to fish from 10 to 40 feet and used Size #4 and #5 Lyman’s, various flatfish and crank baits. I saw a trend developed over the April/May time period. That trend was that I caught fewer fish on each trip. Thirty to forty fish days were common from December through early April. My numbers fell to 20, 11, 4 and finally 0 Lahontan cutthroats on my last trip! I interviewed fisherman as they came in and charter boat personnel and all were experiencing the same results.
What changed? Why do fish shut down and not bite? This is and always has been a hotly debated topic. To me, when the usual techniques fail, the reasons become as important. The reality is that the answers can be as complex scientific experiment and probably due to several simultaneous factors. The solution can be as much to the art as it is science.
It is the nature and amounts of chemical ingredients or impurities in water which, together with temperature, depth, and water movement, largely determine what fishes will be present where and when. In April and May changes in water clarity, barometric pressure and temperature all affected Pyramid Lake. One only has to look at the south end of Pyramid Lake at its confluence with the Truckee River. The snow melt runoff into the lake has spread a starkly visible plume of mud that has traveled to at least Anaho Island making the water have the appearance of a chocolate milk shake.
Studies have shown even small reductions in water clarity (turbidity) reduce predation rates. This decrease in predation with increased turbidity shows predation rates declined by approximately 80% for Lahontan cutthroat trout. There is also abundant research which suggests that changes in barometric pressure have an effect upon fish behavior and particularly feeding behavior. A rising barometer is usually associated with increased feeding activity, and a falling barometer with decreased activity.
Lee A. Weber, Ph.D. Professor of Biology, UNR
With longer day length water temperature is on the rise as the first day’s trip saw a rise in surface temperature of nearly 5 degrees from morning until that afternoon. Pyramid Lake water forms layers (strata) of different temperatures. The strata will form and re-form with the seasons, and their characteristics will have a significant effect upon fish behavior. At different points of the lake several miles apart on the same day, the depth, thickness, and temperature can vary significantly. This stratification largely determines what fish will be where and when. During late fall and winter, trout inhabit predominantly inshore areas. The temperature relationship clearly illustrates the habitat preference of Lahontan cutthroat trout for cool waters. The lowest summer density of cutthroat trout occurs in littoral benthic and inshore surface waters, and the highest density in benthic waters in or below the thermocline. During the summer months, cutthroats are well represented at depths of approximately 60- 200 feet in benthic areas, while avoiding the surface waters of the offshore limnetic zone.
I noticed in late March that many Lahontan cutthroats were in the earlier stages of spawning development and progressed as time passed. Historically, peak Lahontan cutthroat spawning has occurred during April and May. Lahontan cutthroat spawning migration occurred into the Truckee River at river water temperatures varying from approximately 46o to 60oF. Reseachers have shown feeding response is weakest cutthroat are in the mature and ripe stages, when fish are reported not to feed. Lahontan cutthroat, like other trout species, resume feeding and experience their strongest feeding response after spawning completion.
What changed? Everything changed. You can’t simply say the fish aren’t biting because of the phase of the moon. Barometric pressure, turbidity and temperature can change at any moon phase.
I believe the current reluctance of fish to bite at Pyramid at this time is most likely part of spawning behavior. The fish which complete spawning activities will feed voraciously at the end of May and June.
Finally, there is one probable reason I haven’t mentioned and that is an insistence upon catching the fish on the angler’s terms, rather than those of the fish. This gullibility and stubbornness are largely responsible for the failures and frustrations of the fisherman. Always adapt and remember “Fish Consciousness”, the difference between “fisherman and guys that go fishing.”
Paul L. Dalka