Fish and Game Reports Fish Kill at Little Valley Reservoir

Several hundred rainbow trout were found dead Friday, August 8, throughout Little Valley Reservoir near Montpelier, Idaho. The culprit behind the fish kill was a lack of oxygen in the reservoir's water. Fish and Game officials are not sure what caused the low oxygen levels in the reservoir. During a site visit by Fish and Game personnel Friday, a "bloom" of blue-green algae was observed. When blue-green algae begins to decay, it uses up available oxygen in a body of water. But there are a number of other possible causes of low oxygen in water bodies during the summer months. For example, because Little Valley Reservoir is a small, shallow body of water it is susceptible to water column turnover. When storms roll through the area, winds can literally churn the waters, bringing up the poorly oxygenated waters from the bottom. This mixing can result in low oxygen levels throughout a body of water, killing fish and other aquatic organisms. This is the second fish kill from at Little Valley Reservoir since 2006. That year, some of the fish survived and carried over to the following year. It is possible that fish will survive this oxygen depletion event as well. But Fish and Game officials stress that any fish still alive in the reservoir are likely physically stressed, and fishing will be poor until oxygen levels improve. Fish and Game plans to restock the reservoir next year.