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Trout Production and Standing Crop in Colorado's Small Streams, As Related to Environmental Features
Author(s) -
Scarnecchia Dennis L.,
Bergersen Eric P.
Publication year - 1987
Publication title -
north american journal of fisheries management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.587
H-Index - 72
eISSN - 1548-8675
pISSN - 0275-5947
DOI - 10.1577/1548-8659(1987)7<315:tpasci>2.0.co;2
Subject(s) - biomass (ecology) , trout , alkalinity , substrate (aquarium) , streams , environmental science , elevation (ballistics) , salmo , fishery , hydrology (agriculture) , ecology , fish <actinopterygii> , biology , geology , chemistry , mathematics , computer network , computer science , geometry , geotechnical engineering , organic chemistry
Annual production of trout (Salvelinus and Salmo spp.) in 10 small northern Colorado streams (elevation 2,146‐3,139 m above sea level) ranged from 1.5 to 18.4 g/m 2 in 1979 and 1980. Midsummer biomass ranged from 3.9 to 28.2 g/m 2. Ratios of production to biomass ranged from 0.23 to 0.95. Fish production and biomass were related inversely to elevation and directly to substrate diversity, conductivity, alkalinity, and water hardness. Combinations of the various factors explained much of the variation in production: elevation and width:depth ratio, 60%; elevation and substrate diversity, 54%; elevation, substrate diversity, and percentage of zero‐water‐velocity stations, 79%; and elevation, width: depth ratio, and alkalinity, 77%. Similar relationships were developed for midsummer biomass. There was a strong correlation between midsummer biomass and annual production as well as between annual production and the density of fish of desirable size (152 mm long or longer) in each stream. Several relationships are proposed from these data sets that can be used to predict trout production in small, high‐elevation streams. Estimated habitat quality indices for the 11 sections were significantly related to midsummer biomass of trout in 1979 but not in 1980.