Mathematical analysis of the effects of particle retention efficiency on determination of filtration rate

Potential methodological influences on the determination of particle retention efficiency by suspension feeders: Mytilus edulis and Ciona intestinalis

“…The CRs of mussels, which averaged 4.5 l h −1 for the flow-independent phase, were measured using the commonly accepted approach of assuming 100% RE for particles larger than approximately 4 μm (Cranford et al 2011). Rather than being completely retained, 4 μm particles were actually retained at 61 to 86% efficiency, indicating an incorrect use of the indirect method (Williams 1982). Recalculation based on the measured depletion of particles in the 8.25 to 11.25 μm size range yielded a 20% increase in average CR (5.6 l h −1 ; SD = 1.5).…”

“…Coughlan (1969) outlined the fundamental assumptions of the indirect ap proach for estimating CR, including the requirement that the organism retain tracer particles of a predetermined size range with known efficiency (usually 100%). Williams (1982) subsequently showed that the ob served rate of particle removal cannot easily be trans lated into a CR when RE is less than 100%. Knowledge on the relationship between RE and particle size is therefore essential for determining accurate CRs and subsequently for interpreting ecosystem interactions with bivalve populations.…”

Feeding responses of the gastropod Crepidula fornicata to changes in seston concentration

“…5A). We suspect that methodological differences may explain this divergence, because Johnson applied the clearance method (Coughlan 1969) using silt concentration in the CR equation, probably not taking into account the inefficiently retained particles in suspension in his static system (Williams 1982). However, Shumway et al (2003) reported a significant effect of clay particulates on C. fornicata CRs but at a much higher concentration (10 000 mg l -1 ).…”

Retention efficiency and pumping rate of Ostrea edulis in suspensions of Isochrysis galbana

“…O Inter-Research/Printed in F. R Germany (1972a, b, 1973a, b), Palmer and Williams (1980) and Williams (1982). Indirect methods can be used to measure E, but not E.…”