Mariculture of white leg shrimp, Litopenaeus vannamei, provides a crucial protein source for humans. Aquaculture of this species also generates significant nitrogen (N) pollution, which can trigger harmful algal blooms in coastal environments. Although mariculture typically has low profitability, it is essential to establish ecologically and economically sound ways to minimize the release of N into the environment. Oyster polyculture within L. vannamei ponds presents a promising approach for reducing the release of N because oysters have a strong capacity to filter N from the environment while producing a marketable commodity. This study investigated spatiotemporal variations in dissolved N forms (NH₄⁺, NO₂⁻, NO₃⁻, and total N) in shrimp pond water with and without oyster co-cultivation. The results demonstrated that the oyster-integrated pond exhibited significantly lower N pollutant concentrations when compared with the control pond. Specifically, NH₄⁺, NO₂⁻, NO₃⁻, and total nitrogen content decreased by 39.8%, 52.6%, 27.3%, and 51.4%, respectively. Notably, these reductions lowered N concentrations below local regulatory thresholds for the discharge of mariculture wastewater. These findings highlight the potential for the use of oyster polyculture as an effective and dual-purpose method that can be used to mitigate N pollution while maintaining shrimp production yields for L. vannamei mariculture.