The relationship of macroinvertebrate assemblages to water chemistry in a polluted Colorado plains stream
Shieh, S.-H.; Kondratieff, B. C.; Ward, J. V.; Rice, D. A.
published: Jul 26, 1999
ArtNo. ESP141014504005, Price: 29.00 €
Macroinvertebrate assemblages and 27 water chemistry variables were investigated at 8 sampling sites over a 4-year period (1992-1995) in the plains section of the Cache la Poudre River, north central Colorado, influenced by urbanization and agricultural activities. Relationships between macroinvertebrate assemblages and water chemistry variables were examined along a longitudinal chemical gradient using ordination techniques (principal component analysis (PCA), redundancy analysis (RDA), and detrended canonical correspondence analysis (DCCA)). PCA ordination diagrams provide a reasonable two-dimensional representation of both the macroinvertebrate and environmental data. Concentrations of cations (e.g. Ca, Mg, Na, and K ions) exhibited the strongest relationship with macroinvertebrate assemblages along the river section. The inorganic nutrients (e.g. ammonia, total Kjeldahl nitrogen, and total phosphorus), suspended solids, and turbidity were also associated with macroinvertebrate assemblage structure. Temporal trends of macroinvertebrate assemblages, investigated using DCCA, showed that interannual and seasonal variations of macroinvertebrate assemblages were related to increases in concentrations of heavy metals and to decreases in concentrations of inorganic nutrients, suspended solids, and turbidity. Interannual variations were less important than seasonal changes in explaining temporal patterns of macroinvertebrate assemblages. The highest species turnover and the highest interannual and lowest seasonal variation of macroinvertebrate assemblages were found at the reference site.