J. Schutten et al., SUBMERGED MACROPHYTES IN THE RECENTLY FRESHENED LAKE SYSTEM VOLKERAK-ZOOM (THE NETHERLANDS), 1987-1991, Hydrobiologia, 276, 1994, pp. 207-218
Extensive biological research has been carried out during the first fo
ur years after isolation and freshening of Lake Volkerak-Zoom, a forme
r part of the marine-tidal Oosterschelde. Freshening took place in 8 m
onths. Research on submerged macrophytes has been an important part of
the investigation because the aim of the water management was to esta
blish a clear and stable freshwater ecosystem, despite high nutrient l
oading. In the first year after closure the marine Zostera noltii vani
shed. and the brackish water Ruppia maritima colonized the lake. In su
bsequent years, several freshwater species colonized the lake (e.g. Po
tamogeton pusillus, P. pectinatus, Zannichellia palustris, Callitriche
sp. and Chara sp.). The total area in the shallow zone (0.5-5.0 m) co
vered by submerged macrophytes, increased from less than 1 % in 1987 t
o 22.5 % in 1991. Characteristics (height, flowering and fruiting) of
the main species (P. pusillus, P. pectinatus, Z. palustris, R. maritim
a) were closely related to water temperature and secchi depth. Waterfo
wl consumed about half of the production of the submerged macrophytes.