Model-based analysis of oxygen budget and biological processes in the regulated rivers Moselle and Saar: modelling the influence of benthic filter feeders on phytoplankton

Citation
A. Schol et al., Model-based analysis of oxygen budget and biological processes in the regulated rivers Moselle and Saar: modelling the influence of benthic filter feeders on phytoplankton, HYDROBIOL, 410, 1999, pp. 167-176
Citations number
31
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Aquatic Sciences
Journal title
HYDROBIOLOGIA
ISSN journal
0018-8158 → ACNP
Volume
410
Year of publication
1999
Pages
167 - 176
Database
ISI
SICI code
0018-8158(199909)410:<167:MAOOBA>2.0.ZU;2-4
Abstract
The oxygen budget of the regulated rivers Moselle and Saar was analyzed wit h a water quality model for rivers (BfG model). In the river Moselle in mid summer 1994 a strong oxygen decline between Hauconcourt and Palzem was corr elated with a decrease of algal biomass. Further oxygen depletion in later summer in both rivers was a result of oxygen-consuming processes, bacterial carbon oxidation and nitrification, in times of low phytoplankton biomass and photosynthesis. As computed by our model, algal biomass is reduced in s ummer and autumn by highly efficient grazing of the zebra mussel Dreissena polymorpha. From July until September 1994 in the upper part of the river M oselle, a mean reduction of chlorophyll a of about 50% was computed. A dyna mic approach is used to compute the seasonal increase of D. polymorpha popu lation density and filtering capacity as well. The longitudinal decrease of mussel population density in the Moselle towards the river mouth is a cons equence of the decreasing food concentration mainly due to the filtering ac tivity of D. polymorpha in upstream reaches.