Eastern oyster Crassostrea virginica populations have been declining steadily over the past several decades across the North American East coast. The Great Bay Estuary (GBE), located in New Hampshire, is experiencing this loss and restoration efforts have been put into effect. This paper characterizes larval abundances of settled spat and two early stages of C. virginica, D-hinge and veliger, in GBE from 2018 to 2020. Abundances are compared based on date of sampling, year, collection site, and the physicochemical data recorded on each sampling date. It was found that overall, D-hinge larval abundances have declined significantly from 2018 to 2020, whereas veliger abundances have remained steady or increased. Although the physicochemical factors are known to play a role in larval abundance, very little significance was found, suggesting future study may need to be modified to include a broader range of factors (e.g., more temporal sampling). This study indicates that both D-hinge, veliger, and spat settlement occur in GBE before sampling traditionally has started (June), suggesting an earlier than previously thought first spawn of C. virginica in GBE. This finding can be used to enhance restoration efforts as it suggests that spat brought in to augment current sites of active restoration should be released earlier in the season and that recruitment devices should be deployed before the previously thought first spawn of each season.