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The origin of a metalimnetic chrysophyte peak
Author(s) -
Pick F. R.,
Nalewajko C.,
Lean D. R. S.
Publication year - 1984
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1984.29.1.0125
Subject(s) - epilimnion , thermocline , algae , chlorophyll a , oceanography , population , biomass (ecology) , bloom , chlorophyll , hypolimnion , environmental science , biology , nutrient , ecology , geology , eutrophication , botany , demography , sociology
A metalimnetic chlorophyll peak (40–70 µ g·liter ‒1 ) in Jacks Lake, Ontario, was due primarily to a colonial chrysophyte, Chrysosphaerella longispina. The peak was not the result of in situ growth, nor of a passive and progressive accumulation of epilimnetic cells. Instead, a sudden bloom of the algae which occurred in the epilimnion at the end of June, possibly due to excystment, descended rapidly and within no more than 4 days concentrated in a narrow band below the thermocline. There was no net increase in chlorophyll a or cell biomass with time once the population was established in this region. No dividing cells were observed. After about 2 weeks the Chl a concentration at the peak began to decline and the peak disappeared by the end of August. The importance of metalimnetic peaks is greatly exaggerated by the measurement of Chl a.