Written by 2025 FOMR Biological Technician Lisa Leen/Photo of redside shiners by NPS/Rawhouser
Fish Traps
All four of the fish traps (Sodhouse, Busse, Grain Camp, and Page Springs) along the Blitzen River were in operation starting from May 23, 2025. By July 7, 2025, the water flow for the fish ladder for Busse and Grain Camp was too low for the fish to utilize, and the traps were taken out of the water. In early August the Page Springs and Sodhouse traps were also removed.
Ten species of fish were recorded making their way upriver via the fish traps. Seven were native species: the Redband trout (Oncorhynchus mykiss), Redside shiner (Richardsonius balteatus), Bridgelip sucker (Catostomus columbianus), Mountain whitefish (Prosopium williamsoni), Largescale sucker (Catostomus macrocheilus), Longnose dace (Rhinichthys cataractae), and Tui chub (Siphateles bicolor). The three non-native/invasive species recorded were the Common Carp (Cyprinus carpio), Green sunfish (Lepomis cyanellus), and Brown Bullhead (Ictalurus nebulosus).
Busse had the widest range in species, with 9 out of 10 of the species present at that trap, with only the carp absent. Sodhouse came second with 8 out of 10 of the species, with the Tui chub and mountain whitefish absent. Grain camp only had 5 species present, which were the Redband trout, Bridgelip sucker, Redside shiner, Mountain whitefish, and the Green sunfish. Page Springs had the lowest range in species, with the Redband trout and the Mountain whitefish being present. The most common species found in the traps was the Redside shiner, with over 1600 being found in the majority of the traps. Other common species were the mountain whitefish at 225 present, the Bridgelip sucker at 222 present, and the Redband trout at 199. While least common was the carp, with just two being present at the Sodhouse fish trap. The most common non-native species found was the Green sunfish, with 128 present and the least common native fish was the Largescale sucker with 4 present.
Electro Fishing
On July 10, 2025, the Blitzen River was electroshocked via a shock boat to survey for the abundance of Redband trout. It was shocked from the bridge on Sodhouse Lane to Kado bridge on the lower part of the river. Eleven fish were netted, which were 3 Redside shiner, 3 Bridgelip sucker, 4 Redband trout that varied in length of 12-17 inches, and 1 common carp that appeared to have a case of Koi herpes. The carp was taken in as a specimen, while the rest of the fish were released back into the river.
On August 4, 2025, the Blitzen was electroshocked again on the same stretch of the river with the same shock boat. Forty-one fish were netted on this day with 5 different species which were 2 Redband trout, 3 Bridgelip suckers, 9 Largerscale suckers, 11 Redside shiner, and 16 Green sunfish. Being the only nonnative species caught, the sunfish were removed from the river and the rest of the fish were released back into the river.
