In many coastal ecosystems suspension feeding bivalves are responsible for significant energy flow between the benthic and pelagic environments. Hydrodynamics affect this energy flow directly by altering feeding rates and indirectly by altering food supply. This thesis addresses aspects of the relationship between hydrodynamics and the production of the suspension feeding bivalve, Placopecten magellanicus. Indirect effects of flow were studied on small scales, by examining the effect of scallops on deposition of phytoplankton to sand beds in laboratory and field experiments. Scallops enhanced the flux of phytoplankton toward the bed upstream and downstream of the shell increasing deposition by 36-87 %, thus forming a potential food source if resuspended. The magnitude of phytoplankton deposition was a function of sediment grain size. Though individually a small effect, the integrated effect of many such roughness elements may play a significant role in benthic-pelagic coupling. On a larger scale, flow indirectly effects the food supply by regulating the particle flux to bivalve populations. At high densities, suspension feeders may deplete the water of seston at a faster rate than it can be supplied by advection and diffusion, thus limiting production. A modelling study of scallops in suspended culture demonstrated that an existing aquaculture site in Nova Scotia, if expanded to the available area, could experience a 20-30 % depletion in seston concentration. Scaling arguments showed that seston depletion could be reduced by optimising the shape and orientation of the lease to the predominant flow direction. Seston concentration entering the lease depends on larger scale variations in flow. For example, a field study showed that the food supply was altered not only by changes in flow and seston concentration due to the tide, but also changes at larger scales (8-10 days) due to flushing of the bay. Temperature fluctuations associated with these mesoscale flushing events, may also effect production by influencing feeding and respiration rates. In a laboratory study, rapid variations in temperature on an 8-day cycle similar to coastal upwelling events affected scallop metabolism but not growth. At the end of the 48-day experiment, scallop metabolism showed no evidence of thermal acclimation, the metabolic rate still a function of ambient temperature. However, in natural environments where food may be more limited, increased energetic costs at higher temperatures may affect production. The flow can directly affect production by inhibiting feeding; flow affects the pressure differential between the inhalant and exhalant currents against which the bivalve must pump, altering rates of particle capture. A laboratory study showed scallop feeding was inhibited at flow speeds of 25 cm s-1. Furthermore, bi-hourly variations in food supply (flow speed and/or seston concentration) showed that the previous feeding history was a strong determinant of the clearance rate. These experiments demonstrated that the effect of variations in flow speed and seston concentration on feeding behaviour, in particular feeding history, is an equally important component as the indirect effect of varying food supply in modelling bivalve energetics. In a more general sense, these results will ultimately improve predictions of scallop-mediated energy flow through coastal environments.