©2020 Biological and Chemical Oceanography Data Management Office.Funded by the U.S. National Science Foundation
©2020 Biological and Chemical Oceanography Data Management Office.Marine mussels are a highly important coastal ecosystem engineer, creating dense aggregations that can act as a refuge from the many stressors experienced by intertidal organisms. While it is known that their complex 3D structure can have significant impacts on local hydrodynamics, and thus the transport of key metabolites/materials, the role of their individual pumping behavior on these processes has not been well quantified. Our study uses hydrodynamic measurements of mussels in a natural mussel bed, in a mussel aquaculture facility, within a laboratory flume, and utilizing a computational fluid dynamics model that aims to explore the impact of mussel pumping on the hydrodynamics in and around a bivalve aggregation. Field and laboratory measurements showed that dense aggregations of mussels can lower both oxygen and pH levels, and greater decreases were found under low flow conditions. Within a computational fluid dynamics model, a 3-dimensional model bed was created with pumping and non-pumping mussel geometries, and a variety of simulations are run at different background flow conditions, pumping frequencies (% of mussels in bed pumping), and levels of bed complexity (single vs. multi-layer) and oxygen concentrations. Impacts off pumping on hydrodynamic quantities (velocities, turbulent kinetic energy, eddy viscosity) were greatest at the slowest background flow speeds (< 3 cm/s) and within the lower levels of the bed (z= 0-10cm). At these slower flow speeds, the impact of mussel exhalant jets can extend into the overlying boundary layer, increasing the height of the turbulent boundary layer surrounding the aggregation. At faster flow speeds, exhalant jets are pushed down by the background flow and differences in turbulent quantities between pumping and non-pumping simulations are significantly decreased. Overall, our results indicate that mussel pumping activity can ameliorate stagnation of water in dense aggregations, injecting turbulence into the overlying water column and increasing flow within the interstices of the bed. This bio-mixing can have a significant impact on the conditions (i.e., temperature, oxygen levels, pH) within a mussel aggregation.
Last Modified: 04/25/2025
Modified by: Matthew A Reidenbach
| Dataset | Latest Version Date | Current State |
|---|---|---|
| Water chemistry and temperature measured within and above dense aggregation of mussels from a flume experiment conducted July 2023 | 2025-08-18 | Preliminary and in progress |
| Velocity and turbulence measurements around a dense aggregation of mussels from a flume experiment conducted July 2023 | 2025-08-18 | Preliminary and in progress |
| Water Quality and Velocity data collected from Penn Cove Shellfish Hatchery in Washington, USA from July 11 to July 23, 2023 | 2025-10-13 | Data not available |
| Velocity, oxygen, and pH measurements over a mussel bed in water flume at Friday Harbor Labs, Washington in July 2023 | 2025-10-13 | Data not available |
| Particle Image Velocimetry videos of flow and spawning over mussel aggregations within a flume at Friday Harbor Labs, Washington during the summer of 2021 | 2025-11-25 | Data not available |
| Velocity data collected at Brady's Beach in Bamfield British Columbia, Canada in July 2024 | 2025-10-13 | Data not available |
Principal Investigator: Matthew A. Reidenbach (University of Virginia Main Campus)