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Impact of invasive A sian clams, C orbicula spp., on a large river ecosystem
Author(s) -
Pigneur LiseMarie,
Falisse Elodie,
Roland Kathleen,
Everbecq Etienne,
Deliège JeanFrançois,
Smitz Joseph S.,
Doninck Karine,
Descy JeanPierre
Publication year - 2014
Publication title -
freshwater biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.297
H-Index - 156
eISSN - 1365-2427
pISSN - 0046-5070
DOI - 10.1111/fwb.12286
Subject(s) - zooplankton , plankton , phytoplankton , environmental science , biomass (ecology) , productivity , ecosystem , water quality , invasive species , ecology , corbicula fluminea , fishery , primary production , biology , oceanography , nutrient , economics , macroeconomics , geology
Summary Over the past few decades, A siatic clams ( C orbicula spp.) have spread spectacularly in several large European rivers. In the River Meuse, a transnational lowland river, a substantial chlorophyll a decline has been recorded since the mid‐2000s, which seems to be related to the invasion by these exotic bivalves. This study aimed at verifying this hypothesis, using data on clam density from field surveys, water quality monitoring data and a simulation model. Corbicula density was estimated at between 50 and 900 m −2 , depending on the site. Assuming a maximum filtration rate per clam body mass of 0.086 m 3 g C −1 day −1 at 20 °C, derived from the literature, we ran simulations with a non‐stationary model to estimate the impact of the bivalve on the river plankton and water quality. In the stretches where the invasive clams were most abundant, we estimated a 70% loss of phytoplankton biomass, due to their filtration, and a 61% decline in annual primary production compared with a situation without clams. Model simulations also showed that zooplankton may have suffered as much as a 75% loss of biomass. The simulations also point to substantial effects of C orbicula on the river oxygen budget and on nutrient cycling. We suggest that, in the heavily regulated sectors of the river, the loss of planktonic production due to these invasive filter‐feeders negatively affects other suspension feeders and alters ecosystem processes and productivity.