A review and evaluation of the effects of hydrodynamic variables on freshwater mussel communities

Riverine species are governed by the physical (i.e. hydrodynamic) forces generated flowing water. Freshwater also disproportionately imperilled compared to terrestrial and marine in large part due widespread anthropogenic alteration of natural flow regimes which organisms adapted. Sedentary such as freshwater mussels (Bivalvia: Unionoida) especially vulnerable because they unable move quickly response novel patterns created impoundments water withdrawals. We evaluated effects hydrodynamic variables on mussel communities. reviewed literature synthesise relationships between three categories (hydrologic, simple hydraulic, complex hydraulic) community parameters. most useful predicting presence, abundance, richness, provided recommendations help standardise their use characterising habitat reciprocal influence hydraulic at sediment–water interface. Hydrologic stream size were basin- landscape-scale changes At finer scales, variables—mainly shear stress Reynolds number—were more responses. Simple (flow velocity, depth, discharge) had mixed success predictors parameters likely be indirectly correlated responses used calculate variables. More emphasis should placed species- basin-specific when considering hydrologic regime mussels, with an eye towards sustainable management (e.g. restoration, environmental flows). assessed across range discharge a site, combination channel substrate characteristics. This allows calculation that may directly limiting Mussels alter near-bed characteristics, resulting feedbacks local variable s. Researchers consider beds have characteristics continue explore ecological engineering for possible interspecific facilitation benefits species.