Open AccessLong-term changes in nutrient dynamics and plankton communities following the creation of a new reservoir
Author(s) -
Michael Paterson,
K. G. Beaty,
D. L. Findlay,
W Findlay,
Sherry L. Schiff,
Vincent L. St. Louis,
Jason J. Venkiteswaran
Publication year - 2019
Publication title -
canadian journal of fisheries and aquatic sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.09
H-Index - 153
eISSN - 1205-7533
pISSN - 0706-652X
DOI - 10.1139/cjfas-2018-0197
Subject(s) - zooplankton , plankton , nutrient , phytoplankton , trophic level , environmental science , sink (geography) , biomass (ecology) , ecology , trophic state index , oceanography , biology , geography , geology , cartography
Reservoir creation often leads to a “trophic upsurge” of nutrients that may affect communities living near impoundments. We determined the duration of the nutrient upsurge and associated changes in plankton in a study of a new reservoir (Lake 979; L979) in northwestern Ontario that included 2 years pre-impoundment, 16 years of impoundment, and 2 years postimpoundment. Secondarily, we determined allochthonous versus autochthonous carbon (C) use by zooplankton with reservoir development. For the first 6–14 years of impoundment, mean concentrations of total phosphorus (TP), total nitrogen (TN), and dissolved organic carbon increased 3.6, 2.4, and 1.7 times above pre-impoundment levels, respectively, decreasing thereafter. L979 shifted from a net sink to a source of TP and TN for the first 6 years of impoundment. Mean annual biomasses of bacteria, phytoplankton, and zooplankton increased 4.6, 17, and 32.6 times above pre-impoundment levels, respectively, with associated changes in community composition. Bacteria and phytoplankton returned to pre-impoundment levels within 4 and 10 years, respectively, but zooplankton densities remained elevated even after 18 years. Changes in δ 13 C suggested that postimpoundment zooplankton biomass was not supported predominantly by allochthonous C.