Turbulence is a key environmental factor influencing the early life stages of aquatic organisms, yet its role in broadcast spawner recruitment remains underexplored. This study examined the effects of isotropic turbulence with zero mean flow on fertilization success and embryonic development in the invasive quagga mussel (Dreissena bugensis). Turbulence was generated using an oscillating grid for a range of mean energy dissipation rates representative of small-scale hydrodynamics in lakes. Fertilization success was enumerated with two different protocols, one that introduced KCl 5 minutes post gamete exposure to turbulence, and another that had no addition and ran for 60 minutes. A staging scheme was used to enumerate embryonic development as a percentage success reaching morphological milestones over a 24-hour period to assess development. Fertilization success exhibited a complex response to increasing turbulence, with peak success at low to moderate energy dissipation followed by a decline at high turbulence, suggesting that mild mixing enhances gamete encounters, while stronger turbulence reduces fertilization efficiency. Embryonic developmental success increased under moderate turbulence but declined at the highest turbulence treatments, whereas morphology and mortality of embryos was largely unaffected, indicating resilience to the hydrodynamic conditions of lentic environments. These findings improve the understanding of the reproductive ecology of dreissenid mussels and highlight the importance of hydrodynamic context in predicting recruitment and spread of invasive freshwater species.