On Tuesday morning, I drove out to Pyramid Lake in a snowstorm. It wasn’t a nice fluffy snow, but the kind that comes down in little round pellets, sideways, with wind. At Pyramid, this seemed likely to make for either an exceptionally miserable or beautiful morning. I took my chances. I was hoping to see spawning Lahontan cutthroat trout — a worthwhile event in any weather. Spawning, the way that most fish reproduce, happens when a female fish releases unfertilized eggs into the water and a male fish releases “milt” (sperm) over the eggs to fertilize them. Different species have different strategies for spawning — some make “nests” out of gravel or other materials, some guard their eggs until they hatch, some make long spawning migrations, and others do none of those things.
At Pyramid Lake, the Lahontan cutthroat trout spawning story is complex and interesting. Here, trout spend most of the year swimming in Pyramid’s warm and slightly saline lake waters, but during spring, snowmelt rushes down the Truckee River from the Sierra Nevadas, and the influx of fresh, cool water triggers an instinct in the trout to migrate upstream to spawn. Historically, Lahontan cutthroat trout were able to do just this, but during the early 1900s, a drop in lake level associated with upstream water diversions at Derby Dam prevented the fish from entering the Truckee River to spawn for a number of years. This, in combination with a few other factors, led to the extinction of Lahontan cutthroat trout in Pyramid Lake by 1944.
A fisherman at Pyramid Lake, April 13, 2015.
Lahontan cutthroat trout, Sutcliffe, NV. April 13, 2015.
During the 1970s, Lahontan cutthroat trout were reintroduced into Pyramid Lake via a strain of hatchery-raised fish taken from Summit Lake, located in far northwestern Nevada. These fish survived in Pyramid Lake, but have never been known to reproduce here naturally. Instead, eggs and milt are taken from these fish each spring, mixed together, and raised in local fish hatcheries for release.
In 1995, biologists from the Lahontan National Fish Hatchery Complex collected eggs of Lahontan cutthroat trout from the Pilot Mountains of Utah, and brought them to Nevada to start a captive broodstock program. These fish were believed to be descendents of the original strain of Pyramid Lake trout, which had been transplanted to Pilot Peak long ago (is this story confusing yet?). DNA evidence supports this hypothesis. In 2006, Pilot Peak trout were released into Pyramid Lake, and last year, some of these Pilot Peak trout spawned in the lower Truckee River for the first time since 1938.
During higher water years, a fish elevator at Marble Bluff Dam actually lifts fish over the dam so that they can access higher reaches of river during spawning season. There is also a man-made “fishway”, a channel that leads fish past the dam. This year, there isn’t much water coming down the Truckee and the fish elevator is not currently in operation, but at the Pyramid Lake Fisheries facility in Sutcliffe, NV, Lahontan cutthroat trout are swimming up into a man-made channel to spawn.
The fish spawning channel at the Pyramid Lake Fisheries facility in Sutcliffe, NV. April 13, 2015.
Lahontan cutthroat trout in the spawning channel, Sutcliffe, NV. April 13, 2015.
Pyramid Lake is beautiful on a regular day, but on a stormy day, it’s stunning. I drove up over a ridge and the lake came into view, the blues of the water changing from cobalt to caribbean to gray. The mountains behind it were shaded in purples and browns, and dusted with light snow. The sun shone through puffy, cold gray clouds, making shadows on the water.
Entering Sutcliffe, I drove down toward the Pyramid Lake Fisheries facility near the lakeshore, and made my way toward a group of people gathered around the spawning channel. Desmond Mitchell, Lake Operations Supervisor and Supervisor of the Dunn Hatchery in Sutcliffe, welcomed me to join them, and explained what was going on. “We draw the fish up the channel with cool water,” said Mitchell. Once the trout swim up into the channel, they are prevented from swimming back downstream via metal gates, and biologists pull them out of the water to collect their eggs and milt, he explained. “We’ll do this four times this month,” said Mitchell. “We’ve done it once already, we’ll do it two more times. Every Tuesday.”
David Miller, a fishery biologist for the US Fish and Wildlife Service in Reno, was lifting fish from the channel and scanning their heads through a blue metal device, sorting them to see which were tagged. “They have a coated wire tag in their snouts that tell how old they are,” Miller explained. Many of the fish are also tagged on their backs, with a thin colored and numbered wire that can be read without a scanner.
David Miller, Fishery Biologist for the USFWS, scans a fish to see whether it has been tagged. April 13, 2015.
A net full of Lahontan cuttroat trout, Sutcliffe, NV. April 13, 2015.
A numbered tag on the back of a Lahontan cutthroat trout helps biologists to identify the fish. April 13, 2015.
Inside a small building next to the channel, biologists were collecting eggs and milt from “ripe” trout. They held each fish over a small metal bowl, and squeezed out big spurts of orange eggs or white milt. “You put a little pressure on their abdomen and the eggs just fall out,” explained Gaytha Babcock, fishery technician for the USFWS. Today, most of the fish they were processing were of the Summit Lake strain. These will be raised at the Dunn Hatchery, located just up the hill from the spawning channel in Sutcliffe.
“We’ve had about 40 Pilot Peak fish come through in the last two weeks,” said Tim Loux, a fishery biologist with the USFWS. “That’s more than we had last year.” They are very careful with the genetics of the Pilot Peak fish, Loux explained, only mixing the eggs and milt for these fish once they’ve checked the DNA records to see how closely related the fish are and determine whether two fish are a good match for breeding.
Isolated in a separate cage in the channel were two of the Pilot Peak trout, which were noticeably bigger than the rest. One at a time, David Miller took them out of the water, taking measurements and weights for each. The second fish, the larger of the two, weighed in at about 14 pounds. It was pretty immense and impressive, making it hard to imagine fish of the size that used to be caught around here. The record weight at Pyramid? A 41 pounder, caught in 1925!
Extracting the milt from a male Lahontan cutthroat trout. Sutcliffe, NV, April 13, 2015.
Isolated from the Summit Lake trout, two large Lahontan Cutthroat trout of the Pilot Peak strain await processing. Sutcliffe, NV, April 13, 2015.
Measuring a Lahontan cutthroat trout, Sutcliffe, NV. April 13, 2015.
Want to check out the spawning operation? You can visit the Pyramid Lake Fisheries facility in Sutcliffe on one of the next two Tuesdays (April 21st and 28th). For more information, contact Pyramid Lake Fisheries. Get a day use permit for the Pyramid Lake Paiute Reservation ($6) on your way, available at most nearby gas stations.