Summer Production of Coho Salmon Stocked in Mount St. Helens Streams 3–6 Years after the 1980 Eruption

Publisher Website
Google Scholar
Abstract
We monitored habitat use and summer production of stocked underyearling coho salmon Oncorhynchus kisutch from 1983 to 1986 in three streams affected by the 1980 eruption of Mount St. Helens, Washington. Two streams were in the blast area and one was on a volcanic mudflow terrace, Midsummer water temperatures frequently exceeded presumed stressful thresholds and occasionally surpassed the incipient lethal limit. Temperatures at the study sites (up to 29.5°C) may have been the highest ever recorded in small streams in western Washington. In addition, there was relatively little submerged cover and limited pool habitat. Despite the severe conditions created by the eruption, production rates of stocked coho salmon at all sites ranged from 15.1 to 143.8 mg/m2·d (2.3–21.6 g/m2 over an average 150-d summer period) and were equal to or greater than those measured in other streams of comparable size in the region. Coho salmon production in the streams was more strongly influenced by population biomass and...

This publication has 16 references indexed in Scilit: