TITLE:
In Situ Filtration Rates of Blue Mussels (Mytilus edulis) Measured by an Open-Top Chamber Method
AUTHORS:
Florian Lüskow, Hans Ulrik Riisgård
KEYWORDS:
Bivalvia, Filter-Feeding, Zoobenthos, Valve-Opening Degree, Cultivated Algal Cells, Free-Living Bacteria, Particle Retention Efficiency
JOURNAL NAME:
Open Journal of Marine Science,
Vol.8 No.4,
September
5,
2018
ABSTRACT: Blue mussels, Mytilus edulis , form dense beds of both commercial and ecological
importance, and many attempts have been made to determine their
filtration rate. The total time in which mussels actually utilise their filtration
capacity in nature varies greatly, making in situ methods for filtration rate
measurements relevant. Further, it is being debated to what extend filtration
rates measured in the laboratory using cultivated algal cells may apply for
mussels in nature. In the present study, we have used an open-top chamber
setup in order to allow repeated in situ filtration rate measurements of M.
edulis using ambient natural phytoplankton and free-living bacteria. We
found that the in situ measured filtration rates are comparable to filtration
rates obtained in laboratory studies using different methods and controlled
diets of cultivated algal cells. Further, we found that the retention efficiency of
free-living bacteria was between 22.2% and 29.9%, in good agreement with
values from laboratory studies. Our findings support the assumption that
mussels in nature tend to use their filtration capacity when the phytoplankton
concentration is above a certain lower trigger level.