In:
Canadian Journal of Fisheries and Aquatic Sciences, Canadian Science Publishing, Vol. 76, No. 8 ( 2019-08), p. 1459-1469
Kurzfassung:
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.
Materialart:
Online-Ressource
ISSN:
0706-652X
,
1205-7533
DOI:
10.1139/cjfas-2018-0197
Sprache:
Englisch
Verlag:
Canadian Science Publishing
Publikationsdatum:
2019
ZDB Id:
7966-2
ZDB Id:
1473089-3
SSG:
21,3
SSG:
12
