Hansen, A. S. National Environmental Research Institute, ash@dmu.dk
Herman, P. M.J. Centre for Estuarine and Coastal Ecology, NIOO-CEMO, herman@cemo.nioo.knaw.nl

The literature on benthic filter-feeders physiology abounds with controversies about, e.g., water pumping rates, the existence of physiological regulation and the effect of quantity and quality of seston. At least two schools have formed, that partly reject each other's results. A general model, however, should explain all the observed values under a broad range of environmental conditions. The filtration by the blue mussel, Mytilus edulis, was studied as an example. Basic questions in the controversy are whether a) regulation mechanisms of pumping exist and b) if regulation maximizes the organisms' energy gain. Most studies from both schools support the existence of variable rates of clearance with seston quantity, which leaves the question whether this is a result of energy gain optimization mechanisms or simply of limitation by the rate of food processing in the gut. These two theories are tested as alternative formulations in a physiological mussel model including filtration, particle selection and gut characteristics. The results indicate that both theories can describe the observed responses in the literature, depending on actual model parameterization. The modeling supports the existence of regulated clearance rates dependent on seston quantity and quality, but not necessarily as an optimization of net energy gain.
Day: Wednesday, Feb. 3
Time: 03:30 - 03:45pm
Location: Hilton of Santa Fe
Code: SS21WE0345H