Electronic Thesis and Dissertation Repository


Master of Science




Yates, Adam G.


Spatio-temporal patterns of benthic metabolism were measured to determine associations with substrate (cobble vs sand), channel location (main vs side channel), flow regulation (medium-head vs low-head) and temporal variability during the summer months. Benthic metabolism was estimated in two reaches of the Saint John River in New Brunswick, Canada using benthic chambers. General linear models indicated gross primary production (GPP) and community respiration (CR) was greater in cobble substrate in June, but only GPP was greater in July. CR differed between channel locations in July with greater rates in the side channel. Assessment of flow regulation showed greater GPP in the medium-head reach during July and August, but greater CR in July only. Regression analysis indicated temporal variation in GPP was associated with light, whereas CR was associated with GPP and water temperature. Results demonstrate that there are strong spatial and temporal trends for benthic metabolism in a large river.