Present status and changes of the phytoplankton community after
invasion of Neosalanx taihuensis since 1982 in a deep oligotrophic plateau
lake, Lake Fuxian in the subtropical China
Affiliations: Donghu Experimental Station of Lake Ecosystems, State
Key Laboratory for Freshwater Ecology and Biotechnology of China, Institute of
Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
Abstract: Phytoplankton assemblages in the subtrophical oligotrophic Lake
Fuxian, the second deepest lake in China, were investigated monthly from
September 2002 to August 2003. A total of 113 species belonging to seven phyla
were identified, among them, a filamentous green alga, Mougeotia sp., dominated
almost throughout the study period and comprised most of the total
phytoplankton biomass. Mougeotia sp. has made a substantial development during
the past decades: it was absent in 1957, only occasionally present in 1983,
increased substantially in 1993, and became predominant in 2002–2003. It
is likely that natural invasion of the Taihu Lake noodlefish (Neosalanx
taihuensis) has led to a change of dominant herbivorous zooplankton from small
to large calanoid, which has increased grazing pressure on small edible algae,
and thus has indirectly favored the development of the inedible filamentous
Mougeotia sp.
Keywords: phytoplankton community, Neosalanx taihuensis, oligotrophic plateau lake